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Sample records for biventricular assist device

  1. Biventricular assist using a portable driver in combination with implanted devices: preliminary experience.

    Science.gov (United States)

    von Segesser, L K; Tkebuchava, T; Leskosek, B; Marty, B; Pei, Y C; Turina, M

    1997-01-01

    Left ventricular assist systems with portable drive units are increasingly used in the clinical setting. However, such systems usually are not suitable for right ventricular support, and therefore, in the case of biventricular heart failure, they must be combined with other support devices that require additional drive consoles. As a result, most of the benefits of the wearable drive units (early mobilization and outpatient care) are lost. This present study was performed to evaluate biventricular support with implanted assist devices and a portable DC/battery-powered driver (Thoratec TLC-II). Electronic control by nonvolatile RAM accessible via RS232 interface, internal backup emergency battery, and optional manual activation are additional features of this 6 kg biventricular drive unit. In 3 bovine experiments (body weight 70 +/- 5 kg) partial cardiopulmonary bypass (CPB) was established, and two ventricular assist devices were implanted into a preperitoneal pocket on each side after connection to the right atrium and the pulmonary artery and to the left atrium and aorta, respectively. After weaning the patient from CPB, activated coagulation time (ACT) was kept at greater than 180 s, and biventricular support with the portable driver was activated. After 10 min, mean device flow stabilized at 3.5 +/- 0 L/min and remained at that level throughout the ensuing 6 h (3.5 +/- 0.3 L/min; NS). The heart rate moved from 130 +/- 13 beats per minute (bpm) at the end of CPB to 116 +/- 13 bpm after 10 min of assist (p < 0.05). Right atrial pressure moved from 11 +/- 2 mm Hg at the end of CPB to 13 +/- 3 mm Hg after 10 min of assist (not significant [NS]). Mean pulmonary artery pressure was 18 +/- mm Hg at the end of CPB and 17 +/- 5 mm Hg after 10 min of assist (NS). Left atrial pressure was 10 +/- 1 mm Hg at the end of CPB and 13 +/- 3 mm Hg after 10 min of assist (NS). Mean aortic pressure was 73 +/- 11 mm Hg at the end of CPB and 77 +/- 3 mm Hg after 10 min of assist (NS

  2. Personal digital assistant-based, internet-enabled remote communication system for a wearable pneumatic biventricular assist device.

    Science.gov (United States)

    Nam, Kyoung Won; Lee, Jung Joo; Hwang, Chang Mo; Choi, Seong Wook; Son, Ho Sung; Sun, Kyung

    2007-11-01

    Currently, personal mobile communication devices have become quite common, and the applications of such devices have expanded quickly. Remote communication systems might be employed for the telemonitoring of patients or the operating status of their medical devices. In this article, we describe the development of a mobile-based artificial heart telemanagement system for use in a wearable extracorporeal pneumatic biventricular assist device, which is capable of telemonitoring and telecontrolling the operating status of the ventricular assist device from any site. The system developed herein utilized small mobile phones for the client device and adopted a standard transmission control protocol/Internet protocol communication protocol for the purposes of telecommunication. The results of in vitro and animal experiments showed that the telemanagement system developed herein operated in accordance with the desired parameters.

  3. Comparison of total artificial heart and biventricular assist device support as bridge-to-transplantation.

    Science.gov (United States)

    Cheng, Allen; Trivedi, Jaimin R; Van Berkel, Victor H; Massey, H Todd; Slaughter, Mark S

    2016-10-01

    The use of left ventricular assist devices (LVAD) has increased significantly in the last decade. However, right heart dysfunction remains a problem despite the improved outcomes with continuous-flow LVADs. Surgical options for bridge to transplantation (BTT) in patients with biventricular failure are total artificial heart (TAH) or biventricular support (BiVAD). This study examines the differences in pre- and post-transplantation outcomes and survival in patients with TAH or BiVAD support as BTT. The United Network of Organ Sharing database was retrospectively queried from January 2005 to December 2014 to identify adult patients undergoing heart transplantation (n = 17,022). Patients supported with either TAH (n = 212) or BiVAD (n = 366) at the time of transplantation were evaluated. Pre- and post-transplantation Kaplan-Meier survival curves were examined. Cox regression model was used to study the hazard ratios of the association between TAH versus BiVAD support and post-transplant survival. The median age of the study groups was 49.8 ± 12.9 (TAH) and 47.2 ± 13.9 (BiVAD) years (range 18-74 years). There were more men, 87% versus 74%, in the TAH group (p < 0.0001) with greater body mass index, 27.3 ± 5.2 versus 25.6 ± 4.7 (p < 0.0001), compared to those with BiVADs. Creatinine was higher, 1.7 + 1.2 versus 1.3 + 0.8 mg/dL (p < 0.0001), in the TAH group before transplant. The 30-day, one-, and three-year post-transplantation survival was 88%, 78%, and 67%, respectively, for patients with TAH support versus 93%, 83%, and 73% (p = 0.06) for patients with BiVAD support. Cox regression model shows pre-transplant creatinine (HR = 1.21, p = 0.008) is associated with a lower post-transplant survival. TAH is not associated with a worse post-transplant survival (p = 0.1). There was no difference in wait-list survival in patients supported with TAH or BiVAD (p = 0.8). Although there has been a recent

  4. Simulation of Ventricular, Cavo-Pulmonary, and Biventricular Ventricular Assist Devices in Failing Fontan.

    Science.gov (United States)

    Di Molfetta, Arianna; Amodeo, Antonio; Fresiello, Libera; Trivella, Maria Giovanna; Iacobelli, Roberta; Pilati, Mara; Ferrari, Gianfranco

    2015-07-01

    Considering the lack of donors, ventricular assist devices (VADs) could be an alternative to heart transplantation for failing Fontan patients, in spite of the lack of experience and the complex anatomy and physiopathology of these patients. Considering the high number of variables that play an important role such as type of Fontan failure, type of VAD connection, and setting (right VAD [RVAD], left VAD [LVAD], or biventricular VAD [BIVAD]), a numerical model could be useful to support clinical decisions. The aim of this article is to develop and test a lumped parameter model of the cardiovascular system simulating and comparing the VAD effects on failing Fontan. Hemodynamic and echocardiographic data of 10 Fontan patients were used to simulate the baseline patients' condition using a dedicated lumped parameter model. Starting from the simulated baseline and for each patient, a systolic dysfunction, a diastolic dysfunction, and an increment of the pulmonary vascular resistance were simulated. Then, for each patient and for each pathology, the RVAD, LVAD, and BIVAD implantations were simulated. The model can reproduce patients' baseline well. In the case of systolic dysfunction, the LVAD unloads the single ventricle and increases the cardiac output (CO) (35%) and the arterial systemic pressure (Pas) (25%). With RVAD, a decrement of inferior vena cava pressure (Pvci) (39%) was observed with 34% increment of CO, but an increment of the single ventricle external work (SVEW). With the BIVAD, an increment of Pas (29%) and CO (37%) was observed. In the case of diastolic dysfunction, the LVAD increases CO (42%) and the RVAD decreases the Pvci, while both increase the SVEW. In the case of pulmonary vascular resistance increment, the highest CO (50%) and Pas (28%) increment is obtained with an RVAD with the highest decrement of Pvci (53%) and an increment of the SVEW but with the lowest VAD power consumption. The use of numerical models could be helpful in this innovative

  5. Synergy of first principles modelling with predictive control for a biventricular assist device: In silico evaluation study.

    Science.gov (United States)

    Koh, Vivian C A; Yong Kuen Ho; Stevens, Michael C; Salamonsen, Robert F; Lovell, Nigel H; Lim, Einly

    2017-07-01

    Control for dual rotary left ventricular assist devices (LVADs) used as a biventricular assist device (BiVAD) is challenging. If the control system fails, flow imbalance between the systemic and the pulmonary circulations would result, subsequently leading to ventricular suction or pulmonary congestion. With the expectation that advanced control approaches such as model predictive control could address the challenges naturally and effectively, we developed a synergistic first principles model predictive controller (MPC) for the BiVAD. The internal model of the MPC is a simplified state-space model that has been developed and validated in a previous study. A single Frank-Starling (FS) control curve was used to define the target pump flow corresponding to the preload on each side of the heart. The MPC was evaluated in a validated numerical model using three clinical scenarios: blood loss, myocardial recovery, and exercise. Simulation results showed that the MPC was effective in adapting to changes in physiological states without causing ventricular suction or pulmonary congestion. The use of MPC for a BiVAD eliminates the need for two controllers of dual LVADs thus making the task of controller tuning easier.

  6. High pulmonary vascular resistance in addition to low right ventricular stroke work index effectively predicts biventricular assist device requirement.

    Science.gov (United States)

    Imamura, Teruhiko; Kinugawa, Koichiro; Kinoshita, Osamu; Nawata, Kan; Ono, Minoru

    2016-03-01

    Although the right ventricular stroke work index (RVSWI) is a good index for RV function, a low RVSWI is not necessarily an indicator for the need for a right ventricular assist device at the time of left VAD implantation. We here aimed to determine a more precise indicator for the need for a biventricular assist device (BiVAD). In total, 116 patients (mean age, 38 ± 14 years), who underwent hemodynamic assessments preoperatively including 12 BiVAD patients, and had been followed at our institute from 2003 to 2015, were included. Multivariate logistic regression analysis indicated that RVSWI and pulmonary vascular resistance (PVR) were independent predictors of BiVAD requirement (P 5 g/m, PVR 5, PVR > 3.7), (3) RV failure (RVSWI 3.7), and examined. Most of the patients in Group 4 (75 %), with acutely depressed hemodynamics and inflammatory responses in the myocardium, required BiVAD. Overall, patients with BiVAD had a worse survival rate as compared with those with LVAD alone. In conclusion, high PVR in addition to low RVSWI effectively predicts BiVAD requirement.

  7. Bridge to transplantation using paracorporeal biventricular assist devices or the syncardia temporary total artificial heart: is there a difference?

    Science.gov (United States)

    Nguyen, A; Pozzi, M; Mastroianni, C; Léger, P; Loisance, D; Pavie, A; Leprince, P; Kirsch, M

    2015-06-01

    Biventricular support can be achieved using paracorporeal ventricular assist devices (p-BiVAD) or the Syncardia temporary total artificial heart (t-TAH). The purpose of the present study was to compare survival and morbidity between these devices. Data from 2 French neighboring hospitals were reviewed. Between 1996 and 2009, 148 patients (67 p-BiVADs and 81 t-TAH) underwent primary, planned biventricular support. There were 128 (86%) males aged 44±13 years. Preoperatively, p-BiVAD recipients had significantly lower systolic and diastolic blood pressures, more severe hepatic cytolysis and higher white blood cell counts than t-TAH recipients. In contrast, t-TAH patients had significantly higher rates of pre-implant ECLS and hemofiltration. Mean support duration was 79±100 days for the p-BiVAD group and 71±92 for t-TAH group (P=0.6). Forty two (63%) p-BiVAD recipients were bridged to transplantation (39, 58%) or recovery (3, 5%), whereas 51 (63%) patients underwent transplantation in the t-TAH group. Death on support was similar between groups (p-BiVAD, 26 (39%); t-TAH, 30 (37%); P=0.87). Survival while on device was not significantly different between patient groups and multivariate analysis showed that only preimplant diastolic blood pressure and alanine amino-transferase levels were significant predictors of death. Post-transplant survival in the p-BiVAD group was 76±7%, 70±8%, and 58±9% at 1, 3, and 5 years after transplantation, respectively, and was similar to that of the t-TAH group (77±6%, 72±6%, and 70±7%, P=0.60). Survival while on support and up to 5 years after heart transplantation was not significantly different in patients supported by p-BiVADs or t-TAH. Multivariate analysis revealed that survival while on transplantation was not affected by the type of device implanted.

  8. A durability study of a paracorporeal pulsatile electro-mechanical pneumatic biventricular assist device.

    Science.gov (United States)

    Choi, Hyuk; Lee, Heung-Man; Nam, Kyoung Won; Choi, Jaesoon; Lee, Jung-Joo; Kim, Ho Chul; Song, Seung Joon; Ahn, Chi Bum; Son, Ho Sung; Lim, Choon Hak; Son, Kuk Hui; Park, Yong Doo; Jeong, Gi Seok; Sun, Kyung

    2011-06-01

    In 2002, the paracorporeal pulsatile electro-mechanical pneumatic ventricular assist device (VAD) began to be developed by the Korea Artificial Organ Center at Korea University under a Health & Medical Technology Research and Development program which finished in 2008. In vitro durability testing was conducted on the paracorporeal pulsatile pneumatic VAD to determine device durability and to evaluate device failures. The 1- and 2-year reliability of the paracorporeal pulsatile pneumatic VAD was shown to be 91.2% and 54.9%, respectively, with an 80% confidence level. Failure modes were analyzed using fault tree analysis, with customized software continuously acquiring data during the test period. After this period, 21 in vivo animal tests were done, with 14 cases of left atrium to left ventricle (LV) inflow cannulation (36Fr)/outflow grafting to descending aorta, and seven cases of apex cannulation of LV to descending aorta (12 mm). The longest postoperative day (182 days) in Korea was recently recorded in in vivo animal testing (bovine, 90 kg, male, 3.5-4.0 L/min flow rate, and 55 bpm). © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  9. Risk stratification in patients with advanced heart failure requiring biventricular assist device support as a bridge to cardiac transplantation.

    Science.gov (United States)

    Cheng, Richard K; Deng, Mario C; Tseng, Chi-hong; Shemin, Richard J; Kubak, Bernard M; MacLellan, W Robb

    2012-08-01

    Prior studies have identified risk factors for survival in patients with end-stage heart failure (HF) requiring left ventricular assist device (LVAD) support. However, patients with biventricular HF may represent a unique cohort. We retrospectively evaluated a consecutive cohort of 113 adult, end-stage HF patients at University of California Los Angeles Medical Center who required BIVAD support between 2000 and 2009. Survival to transplant was 66.4%, with 1-year actuarial survival of 62.8%. All patients were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Level 1 or 2 and received Thoratec (Pleasanton, CA) paracorporeal BIVAD as a bridge to transplant. Univariate analyses showed dialysis use, ventilator use, extracorporal membrane oxygenation use, low cardiac output, preserved LV ejection fraction (restrictive physiology), normal-to-high sodium, low platelet count, low total cholesterol, low high-density and high-density lipoprotein, low albumin, and elevated aspartate aminotransferase were associated with increased risk of death. We generated a scoring system for survival to transplant. Our final model, with age, sex, dialysis, cholesterol, ventilator, and albumin, gave a C-statistic of 0.870. A simplified system preserved a C-statistic of 0.844. Patients were divided into high-risk or highest-risk groups (median respective survival, 367 and 17 days), with strong discrimination between groups for death. We have generated a scoring system that offers high prognostic ability for patients requiring BIVAD support and hope that it may assist in clinical decision making. Further studies are needed to prospectively validate our scoring system. Copyright © 2012 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  10. Physiological control of dual rotary pumps as a biventricular assist device using a master/slave approach.

    Science.gov (United States)

    Stevens, Michael C; Wilson, Stephen; Bradley, Andrew; Fraser, John; Timms, Daniel

    2014-09-01

    Dual rotary left ventricular assist devices (LVADs) can provide biventricular mechanical support during heart failure. Coordination of left and right pump speeds is critical not only to avoid ventricular suction and to match cardiac output with demand, but also to ensure balanced systemic and pulmonary circulatory volumes. Physiological control systems for dual LVADs must meet these objectives across a variety of clinical scenarios by automatically adjusting left and right pump speeds to avoid catastrophic physiological consequences. In this study we evaluate a novel master/slave physiological control system for dual LVADs. The master controller is a Starling-like controller, which sets flow rate as a function of end-diastolic ventricular pressure (EDP). The slave controller then maintains a linear relationship between right and left EDPs. Both left/right and right/left master/slave combinations were evaluated by subjecting them to four clinical scenarios (rest, postural change, Valsalva maneuver, and exercise) simulated in a mock circulation loop. The controller's performance was compared to constant-rotational-speed control and two other dual LVAD control systems: dual constant inlet pressure and dual Frank-Starling control. The results showed that the master/slave physiological control system produced fewer suction events than constant-speed control (6 vs. 62 over a 7-min period). Left/right master/slave control had lower risk of pulmonary congestion than the other control systems, as indicated by lower maximum EDPs (15.1 vs. 25.2-28.4 mm Hg). During exercise, master/slave control increased total flow from 5.2 to 10.1 L/min, primarily due to an increase of left and right pump speed. Use of the left pump as the master resulted in fewer suction events and lower EDPs than when the right pump was master. Based on these results, master/slave control using the left pump as the master automatically adjusts pump speed to avoid suction and increases pump flow

  11. Optimal pacing for right ventricular and biventricular devices: minimizing, maximizing, and right ventricular/left ventricular site considerations.

    Science.gov (United States)

    Gillis, Anne M

    2014-10-01

    The results from numerous clinical studies provide guidance for optimizing outcomes related to RV or biventricular pacing in the pacemaker and ICD populations. (1) Programming algorithms to minimize RV pacing is imperative in patients with dual-chamber pacemakers who have intrinsic AV conduction or intermittent AV conduction block. (2) Dual-chamber ICDs should be avoided in candidates without an indication for bradycardia pacing. (3) Alternate RV septal pacing sites may be considered at the time of pacemaker implantation. (4) Biventricular pacing may be beneficial in some patients with mild LV dysfunction. (5) LV lead placement at the site of latest LV activation is desirable. (6) Programming CRT systems to achieve biventricular/LV pacing >98.5% is important. (7) Protocols for AV and VV optimization in patients with CRT are not recommended after device implantation but may be considered for CRT nonresponders. (8) Novel algorithms to maximize the benefit of CRT are in evolution further.

  12. Assistive Devices

    Science.gov (United States)

    If you have a disability or injury, you may use a number of assistive devices. These are tools, products or types of equipment that help you perform tasks and activities. They may help you move around, see, communicate, eat, or get ...

  13. Left ventricular function and visual phase analysis with equilibrium radionuclide angiography in patients with biventricular device

    International Nuclear Information System (INIS)

    Muxi, Africa; Setoain, Francisco J.; Pons, Francisca; Paredes, Pilar; Duch, Joan; Fuertes, Silvia; Ortin, Jaime; Mont, Lluis; Diaz-Infante, Ernesto

    2008-01-01

    Cardiac resynchronisation therapy (CRT) is a technique indicated in patients with moderate to severe heart failure and ventricular dyssynchrony. To evaluate left ventricular ejection fraction (LVEF) and synchronisation changes after CRT with a biventricular pacing implant, we used an equilibrium radionuclide angiography (ERNA). Fifty patients were studied. An ERNA was made 72 h and 6 months after the implant. Two acquisitions were performed: with the CRT device connected and after disconnecting it. In the follow-up, responders were defined as those who had improved in accordance with various clinical variables. Quantitative changes in LVEF and visual changes in synchronisation (phase analysis) were studied comparing the two studies and also comparing the connected and disconnected modes. At 6 months, 30 patients were defined as responders. LVEF increased significantly at 6 months compared with the 72-h study only in responders. At 72 h, the number of patients showing a decrease in LVEF (p < 0.05) or a synchronisation worsening after disconnecting the device was higher in responders than in nonresponders. At 6 months, 57% of responders had no synchronisation changes between the connected and disconnected modes, suggesting a resynchronisation process. ERNA permits the study of resynchronisation patients, showing a statistical LVEF improvement at 6 months. Moreover, visual phase analysis permits the study of the mechanism involved in the response, with an important number of responders with no changes between the two modes at 6 months. In the 72-h study, after disconnection of the device, LVEF and resynchronisation worsening can predict patient improvement at 6 months. (orig.)

  14. Transesophageal Echocardiography-Guided Epicardial Left Ventricular Lead Placement by Video-Assisted Thoracoscopic Surgery in Nonresponders to Biventricular Pacing and Previous Chest Surgery.

    Science.gov (United States)

    Schroeder, Carsten; Chung, Jane M; Mackall, Judith A; Cakulev, Ivan T; Patel, Aaron; Patel, Sunny J; Hoit, Brian D; Sahadevan, Jayakumar

    2018-06-14

    The aim of the study was to study the feasibility, safety, and efficacy of transesophageal echocardiography-guided intraoperative left ventricular lead placement via a video-assisted thoracoscopic surgery approach in patients with failed conventional biventricular pacing. Twelve patients who could not have the left ventricular lead placed conventionally underwent epicardial left ventricular lead placement by video-assisted thoracoscopic surgery. Eight patients had previous chest surgery (66%). Operative positioning was a modified far lateral supine exposure with 30-degree bed tilt, allowing for groin and sternal access. To determine the optimal left ventricular location for lead placement, the left ventricular surface was divided arbitrarily into nine segments. These segments were transpericardially paced using a hand-held malleable pacing probe identifying the optimal site verified by transesophageal echocardiography. The pacing leads were screwed into position via a limited pericardiotomy. The video-assisted thoracoscopic surgery approach was successful in all patients. Biventricular pacing was achieved in all patients and all reported symptomatic benefit with reduction in New York Heart Association class from III to I-II (P = 0.016). Baseline ejection fraction was 23 ± 3%; within 1-year follow-up, the ejection fraction increased to 32 ± 10% (P = 0.05). The mean follow-up was 566 days. The median length of hospital stay was 7 days with chest tube removal between postoperative days 2 and 5. In patients who are nonresponders to conventional biventricular pacing, intraoperative left ventricular lead placement using anatomical and functional characteristics via a video-assisted thoracoscopic surgery approach is effective in improving heart failure symptoms. This optimized left ventricular lead placement is feasible and safe. Previous chest surgery is no longer an exclusion criterion for a video-assisted thoracoscopic surgery approach.

  15. Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Khuansiri Narajeenron

    2017-04-01

    Full Text Available Audience: The audience for this classic team-based learning (cTBL session is emergency medicine residents, faculty, and students; although this topic is applicable to internal medicine and family medicine residents. Introduction: A left ventricular assist device (LVAD is a mechanical circulatory support device that can be placed in critically-ill patients who have poor left ventricular function. After LVAD implantation, patients have improved quality of life.1 The number of LVAD patients worldwide continues to rise. Left-ventricular assist device patients may present to the emergency department (ED with severe, life-threatening conditions. It is essential that emergency physicians have a good understanding of LVADs and their complications. Objectives: Upon completion of this cTBL module, the learner will be able to: 1 Properly assess LVAD patients’ circulatory status; 2 appropriately resuscitate LVAD patients; 3 identify common LVAD complications; 4 evaluate and appropriately manage patients with LVAD malfunctions. Method: The method for this didactic session is cTBL.

  16. Cerebrovascular accidents in patients with a ventricular assist device.

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    Tsukui, Hiroyuki; Abla, Adib; Teuteberg, Jeffrey J; McNamara, Dennis M; Mathier, Michael A; Cadaret, Linda M; Kormos, Robert L

    2007-07-01

    A cerebrovascular accident is a devastating adverse event in a patient with a ventricular assist device. The goal was to clarify the risk factors for cerebrovascular accident. Prospectively collected data, including medical history, ventricular assist device type, white blood cell count, thrombelastogram, and infection, were reviewed retrospectively in 124 patients. Thirty-one patients (25%) had 48 cerebrovascular accidents. The mean ventricular assist device support period was 228 and 89 days in patients with and without cerebrovascular accidents, respectively (P cerebrovascular accidents occurred within 4 months after implantation. Actuarial freedom from cerebrovascular accident at 6 months was 75%, 64%, 63%, and 33% with the HeartMate device (Thoratec Corp, Pleasanton, Calif), Thoratec biventricular ventricular assist device (Thoratec Corp), Thoratec left ventricular assist device (Thoratec), and Novacor device (WorldHeart, Oakland, Calif), respectively. Twenty cerebrovascular accidents (42%) occurred in patients with infections. The mean white blood cell count at the cerebrovascular accident was greater than the normal range in patients with infection (12,900/mm3) and without infection (9500/mm3). The mean maximum amplitude of the thrombelastogram in the presence of infection (63.6 mm) was higher than that in the absence of infection (60.7 mm) (P = .0309). The risk of cerebrovascular accident increases with a longer ventricular assist device support period. Infection may activate platelet function and predispose the patient to a cerebrovascular accident. An elevation of the white blood cell count may also exacerbate the risk of cerebrovascular accident even in patients without infection. Selection of device type, prevention of infection, and meticulous control of anticoagulation are key to preventing cerebrovascular accident.

  17. Efficient adders for assistive devices

    Directory of Open Access Journals (Sweden)

    Mansi Jhamb

    2017-02-01

    Full Text Available The Body sensor network [IEEE 802.15] is a wireless communication network consisting of assistive devices which are of prime importance in medical applications. The delay critical and power hungry blocks in these assistive devices are designed so that they consume less power, have low latency and require a lesser area on chip. In this paper, we present a qualitative as well as a quantitative analysis of an asynchronous pipelined adder design with two latest computation completion sensing approaches based on Pseudo NMOS logic and other based on C-element. The Pseudo NMOS based completion sensing approach provides a maximum improvement of 76.92% in critical path delay at supply voltage of 1.2 V and the maximum drop in power dissipation has been observed at a supply voltage of 1.1 V which is 85.60% as compared to C-element based completion sensing approach. Even at low voltages such as 0.8 V, there is a significant improvement in speed and power which is 75.64% and 74.79% respectively. Since the adder is the most widely used component in all present day assistive devices, this analysis acts as a pointer for the application of asynchronous pipelined circuits with efficient Pseudo NMOS based completion sensing approach in low voltage/low power rehabilitative devices.

  18. Total artificial heart in the pediatric patient with biventricular heart failure.

    Science.gov (United States)

    Park, S S; Sanders, D B; Smith, B P; Ryan, J; Plasencia, J; Osborn, M B; Wellnitz, C M; Southard, R N; Pierce, C N; Arabia, F A; Lane, J; Frakes, D; Velez, D A; Pophal, S G; Nigro, J J

    2014-01-01

    Mechanical circulatory support emerged for the pediatric population in the late 1980s as a bridge to cardiac transplantation. The Total Artificial Heart (TAH-t) (SynCardia Systems Inc., Tuscon, AZ) has been approved for compassionate use by the Food and Drug Administration for patients with end-stage biventricular heart failure as a bridge to heart transplantation since 1985 and has had FDA approval since 2004. However, of the 1,061 patients placed on the TAH-t, only 21 (2%) were under the age 18. SynCardia Systems, Inc. recommends a minimum patient body surface area (BSA) of 1.7 m(2), thus, limiting pediatric application of this device. This unique case report shares this pediatric institution's first experience with the TAH-t. A 14-year-old male was admitted with dilated cardiomyopathy and severe biventricular heart failure. The patient rapidly decompensated, requiring extracorporeal life support. An echocardiogram revealed severe biventricular dysfunction and diffuse clot formation in the left ventricle and outflow tract. The decision was made to transition to biventricular assist device. The biventricular failure and clot formation helped guide the team to the TAH-t, in spite of a BSA (1.5 m(2)) below the recommendation of 1.7 m(2). A computed tomography (CT) scan of the thorax, in conjunction with a novel three-dimensional (3D) modeling system and team, assisted in determining appropriate fit. Chest CT and 3D modeling following implantation were utilized to determine all major vascular structures were unobstructed and the bronchi were open. The virtual 3D model confirmed appropriate device fit with no evidence of compression to the left pulmonary veins. The postoperative course was complicated by a left lung opacification. The left lung anomalies proved to be atelectasis and improved with aggressive recruitment maneuvers. The patient was supported for 11 days prior to transplantation. Chest CT and 3D modeling were crucial in assessing whether the device would

  19. Machines versus medication for biventricular heart failure: focus on the total artificial heart.

    Science.gov (United States)

    Arabia, Francisco A; Moriguchi, Jaime D

    2014-09-01

    The medical/surgical management of advanced heart failure has evolved rapidly over the last few decades. With better understanding of heart failure pathophysiology, new pharmacological agents have been introduced that have resulted in improvements in survival. For those patients that fail to improve, mechanical circulatory support with left ventricular assist devices and total artificial hearts (TAHs) have served as a beneficial bridge to transplantation. The TAH has continued to play a significant role as a bridge to transplantation in patients with biventricular failure and more selected indications that could not be completely helped with left ventricular assist devices. Improved survival with the TAH has resulted in more patients benefiting from this technology. Improvements will eventually lead to a totally implantable device that will permanently replace the failing human heart.

  20. Wearable Assistive Devices for the Blind

    OpenAIRE

    Velazquez, Ramiro

    2016-01-01

    Assistive devices are a key aspect in wearable systems for biomedical applications, as they represent potential aids for people with physical and sensory disabilities that might lead to improvements in the quality of life. This chapter focuses on wearable assistive devices for the blind. It intends to review the most significant work done in this area, to present the latest approaches for assisting this population and to understand universal design concepts for the development of wearable ass...

  1. Assistive Devices for Students with Disabilities.

    Science.gov (United States)

    Wisniewski, Lech; Sedlak, Robert

    1992-01-01

    Describes a variety of devices that can assist students with disabilities. Highlights recently developed devices for students with specific learning disabilities, and with vision, hearing, health, physical, and speech and language impairments. The devices can help rehabilitate, reeducate, facilitate normalcy, or augment current functioning. (GLR)

  2. Evaluation of Automated Flagger Assistance Devices

    Science.gov (United States)

    2018-02-01

    Automated flagger assistance devices (AFADs) are designed to improve worker safety by replacing flaggers who are typically located near traffic approaching a work zone. In this study, a new AFAD developed by the Missouri Department of Transportation ...

  3. The Achilles' heel of left ventricular assist device therapy: right ventricle.

    Science.gov (United States)

    Ranganath, Neel K; Smith, Deane E; Moazami, Nader

    2018-06-01

    Many patients suffer from either persistent right ventricular failure (RVF) at the time of left ventricular assist device (LVAD) or have ongoing symptoms consistent with RVF during chronic mechanical circulatory support. The lack of long-term right ventricular assist devices (RVADs) has limited the impact that mechanical circulatory support can provide to patients with biventricular failure. We aim to review the entire spectrum of RVF in patients receiving LVADs and reflect on why this entity remains the Achilles' heel of LVAD therapy. In the early postoperative period, LVAD implantation reduces right ventricle (RV) afterload, but RV dysfunction may be exacerbated secondary to increased venous return. With prolonged therapy, the decreased RV afterload leads to improved RV contractile function. Bayesian statistical models outperform previously published preoperative risk scores by considering inter-relationships and conditional probabilities amongst independent variables. Various echocardiographic parameters and the pulmonary artery pulsatility index have shown promise in predicting post-LVAD RVF. Recent publications have delineated the emergence of 'delayed' RVF. Several devices are currently being investigated for use as RVADs. Post-LVAD RVF depends on the RV's ability to adapt to acute hemodynamic changes imposed by the LVAD. Management options are limited due to the lack of an easily implantable, chronic-use RVAD.

  4. Experience With a Long-term Pulsatile Ventricular Assist Device as a Bridge to Heart Transplant in Adults.

    Science.gov (United States)

    Gómez Bueno, Manuel; Segovia Cubero, Javier; Serrano Fiz, Santiago; Ugarte Basterrechea, Juan; Hernández Pérez, Francisco José; Goirigolzarri Artaza, Josebe; Castedo Mejuto, Evaristo; Burgos Lázaro, Raúl; García Montero, Carlos; Moñivas Palomero, Vanessa; Mingo Santos, Susana; González Román, Ana Isabel; Álvarez Avelló, José Manuel; Vidal Fernández, Mercedes; Forteza Gil, Alberto; Alonso-Pulpón, Luis

    2017-09-01

    Most long-term ventricular assist devices (VADs) that are currently implanted are intracorporeal continuous-flow devices. Their main limitations include their high cost and inability to provide biventricular support. The aim of this study was to describe the results of using paracorporeal pulsatile-flow VADs as a bridge to transplant (BTT) in adult patients. Retrospective analysis of the characteristics, complications, and outcomes of a single-center case series of consecutive patients treated with the EXCOR VAD as BTT between 2009 and 2015. During the study period, 25 VADs were implanted, 6 of them biventricular. Ventricular assist devices were indicated directly as a BTT in 12 patients and as a bridge to decision in 13 due to the presence of potentially reversible contraindications or chance of heart function recovery. Twenty patients (80%) were successfully bridged to heart transplant after a median of 112 days (range, 8-239). The main complications included infectious (52% of patients), neurological events (32%, half of them fatal), bleeding (28%), and VAD malfunction requiring component replacement (28%). Eighty percent of patients with the EXCOR VAD as BTT achieved the goal after an average of almost 4 months of support. The most frequent complications were infectious, and the most severe were neurological. In our enivonment, the use of these pulsatile-flow VAD as BTT is a feasible strategy that obtains similar outcomes to those of intracorporeal continuous-flow devices. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Advances in bioartificial liver assist devices.

    Science.gov (United States)

    Patzer, J F

    2001-11-01

    Rapid advances in development of bioartificial liver assist devices (BLADs) are exciting clinical interest in the application of BLAD technology for support of patients with acute liver failure. Four devices (Circe Biomedical HepatAssist, Vitagen ELAD, Gerlach BELS, and Excorp Medical BLSS) that rely on hepatocytes cultured in hollow-fiber membrane technology are currently in various stages of clinical evaluation. Several alternative approaches for culture and perfusion of hepatocytes have been evaluated in preclinical, large animal models of liver failure, or at a laboratory scale. Engineering design issues with respect to xenotransplantation, BLAD perfusion, hepatocyte functionality and culture maintenance, and ultimate distribution of a BLAD to a clinical site are delineated.

  6. Mycobacterium chimaera left ventricular assist device infections.

    Science.gov (United States)

    Balsam, Leora B; Louie, Eddie; Hill, Fred; Levine, Jamie; Phillips, Michael S

    2017-06-01

    A global outbreak of invasive Mycobacterium chimaera infections after cardiac surgery has recently been linked to bioaerosols from contaminated heater-cooler units. The majority of cases have occurred after valvular surgery or aortic graft surgery and nearly half have resulted in death. To date, infections in patients with left ventricular assist devices (LVADs) have not been characterized in the literature. We report two cases of device-associated M. chimaera infection in patients with continuous-flow LVADs and describe challenges related to diagnosis and management in this population. © 2017 Wiley Periodicals, Inc.

  7. Calculation of the ALMA Risk of Right Ventricular Failure After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Loforte, Antonio; Montalto, Andrea; Musumeci, Francesco; Amarelli, Cristiano; Mariani, Carlo; Polizzi, Vincenzo; Lilla Della Monica, Paola; Grigioni, Francesco; Di Bartolomeo, Roberto; Marinelli, Giuseppe

    2018-05-08

    Right ventricular failure after continuous-flow left ventricular assist device (LVAD) implantation is still an unsolved issue and remains a life-threatening event for patients. We undertook this study to determine predictors of the patients who are candidates for isolated LVAD therapy as opposed to biventricular support (BVAD). We reviewed demographic, echocardiographic, hemodynamic, and laboratory variables for 258 patients who underwent both isolated LVAD implantation and unplanned BVAD because of early right ventricular failure after LVAD insertion, between 2006 and 2017 (LVAD = 170 and BVAD = 88). The final study patients were randomly divided into derivation (79.8%, n = 206) and validation (20.1%, n = 52) cohorts. Fifty-seven preoperative risk factors were compared between patients who were successfully managed with an LVAD and those who required a BVAD. Nineteen variables demonstrated statistical significance on univariable analysis. Multivariable logistic regression analysis identified destination therapy (odds ratio [OR] 2.0 [1.7-3.9], p = 0.003), a pulmonary artery pulsatility index right ventricle/left ventricle end-diastolic diameter ratio >0.75 (OR 2.7 [1.5-5.5], p = 0.001), an right ventricle stroke work index 17 (OR 3.5 [1.9-6.9], p the major predictors of the need for BVAD. Using these data, we propose a simple risk calculator to determine the suitability of patients for isolated LVAD support in the era of continuous-flow mechanical circulatory support devices.

  8. Association between frequency of atrial and ventricular ectopic beats and biventricular pacing percentage and outcomes in patients with cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Ruwald, Martin H; Mittal, Suneet; Ruwald, Anne-Christine

    2014-01-01

    -defibrillator device with data available on biventricular pacing percentage and pre-implantation 24-h Holter recordings were included. Using logistic regression, we estimated the influence of ectopic beats on the percentage of biventricular pacing. Reverse remodeling was measured as reductions in atrial and left...

  9. Brain-controlled body movement assistance devices and methods

    Energy Technology Data Exchange (ETDEWEB)

    Leuthardt, Eric C.; Love, Lonnie J.; Coker, Rob; Moran, Daniel W.

    2017-01-10

    Methods, devices, systems, and apparatus, including computer programs encoded on a computer storage medium, for brain-controlled body movement assistance devices. In one aspect, a device includes a brain-controlled body movement assistance device with a brain-computer interface (BCI) component adapted to be mounted to a user, a body movement assistance component operably connected to the BCI component and adapted to be worn by the user, and a feedback mechanism provided in connection with at least one of the BCI component and the body movement assistance component, the feedback mechanism being configured to output information relating to a usage session of the brain-controlled body movement assistance device.

  10. The medical physics of ventricular assist devices

    International Nuclear Information System (INIS)

    Wood, Houston G; Throckmorton, Amy L; Untaroiu, Alexandrina; Song Xinwei

    2005-01-01

    Millions of patients, from infants to adults, are diagnosed with congestive heart failure each year all over the world. A limited number of donor hearts available for these patients results in a tremendous demand for alternative, supplemental circulatory support in the form of artificial heart pumps or ventricular assist devices (VADs). The development procedure for such a device requires careful consideration of biophysical factors, such as biocompatibility, haemolysis, thrombosis, implantability, physiologic control feasibility and pump performance. Conventional pump design equations based on Newton's law and computational fluid dynamics (CFD) are readily used for the initial design of VADs. In particular, CFD can be employed to predict the pressure-flow performance, hydraulic efficiencies, flow profile through the pump, stress levels and biophysical factors, such as possible blood cell damage. These computational flow simulations may involve comprehensive steady and transient flow analyses. The transient simulations involve time-varying boundary conditions and virtual modelling of the impeller rotation in the blood pumps. After prototype manufacture, laser flow measurements with sophisticated optics and mock circulatory flow loop testing assist with validation of pump design and identification of irregular flow patterns for optimization. Additionally, acute and chronic animal implants illustrate the blood pump's ability to support life physiologically. These extensive design techniques, coupled with fundamental principles of physics, ensure a reliable and effective VAD for thousands of heart failure patients each year

  11. Endocarditis in left ventricular assist device

    Science.gov (United States)

    Thyagarajan, Braghadheeswar; Kumar, Monisha Priyadarshini; Sikachi, Rutuja R; Agrawal, Abhinav

    2016-01-01

    Summary Heart failure is one of the leading causes of death in developed nations. End stage heart failure often requires cardiac transplantation for survival. The left ventricular assist device (LVAD) has been one of the biggest evolvements in heart failure management often serving as bridge to transplant or destination therapy in advanced heart failure. Like any other medical device, LVAD is associated with complications with infections being reported in many patients. Endocarditis developing secondary to the placement of LVAD is not a frequent, serious and difficult to treat condition with high morbidity and mortality. Currently, there are few retrospective studies and case reports reporting the same. In our review, we found the most common cause of endocarditis in LVAD was due to bacteria. Both bacterial and fungal endocarditis were associated with high morbidity and mortality. In this review we will be discussing the risk factors, organisms involved, diagnostic tests, management strategies, complications, and outcomes in patients who developed endocarditis secondary to LVAD placement. PMID:27672540

  12. Biventricular pacemaker implantation with the BV Pulsera

    Energy Technology Data Exchange (ETDEWEB)

    Wright, J.D.W.; Todd, D.; Waktare, J.E.P.; Hughes, S.; Abell, C. [The Cardiothoracic Centre, Liverpool (United Kingdom)

    2005-07-01

    The BV Pulsera mobile X-ray system is used for biventricular pacemaker implantation in a surgical environment. It provides high-quality images of the moving structures, including the fine coronary leads, and can be used for long fluoroscopy runs without overheating. (orig.)

  13. Biventricular pacemaker implantation with the BV Pulsera

    International Nuclear Information System (INIS)

    Wright, J.D.W.; Todd, D.; Waktare, J.E.P.; Hughes, S.; Abell, C.

    2005-01-01

    The BV Pulsera mobile X-ray system is used for biventricular pacemaker implantation in a surgical environment. It provides high-quality images of the moving structures, including the fine coronary leads, and can be used for long fluoroscopy runs without overheating. (orig.)

  14. Design of wheel-type walking-assist device

    International Nuclear Information System (INIS)

    Jung, Seung Ho; Kim, Seung Ho; Kim, Chang Hoi; Seo, Yong Chil; Jung, Kyung Min; Lee, Sung Uk

    2006-03-01

    In this research, a outdoor wheel-type walking-assist device is developed to help an elder having a poor muscular strength at legs for walking, sitting and standing up easily at outdoors, and also for going and downing stairs. In conceptually designing, the environments of an elder's activity, the size of an elder's body and a necessary function of helping an elder are considered. This device has 4 wheels for stability. When an elder walks in incline plane with the proposed device, a rear-wing is rotated to keep the supporting device horizontal, regardless of an angle of inclination. A height-controlling device, which can control the height of the supporting device for adjusting an elder's height, is varied vertically to help an elder to sit and stand-up easily. Moreover, a outdoor wheel-type walking-assist device is conceptually designed and is made. In order to design it, the preview research is investigated firstly. On the basis of the proposed walking-assist device, the outdoor walking-assist device is designed and made. The outdoor wheel-type walking-assist device can go and down stairs automatically. This device go up and down the stair of having maximum 20cm height and an angle of 25 degrees with maximum 4 sec/stairs speed, and move at flatland with 60cm/sec speed

  15. Reference Device-Assisted Adaptive Location Fingerprinting

    Directory of Open Access Journals (Sweden)

    Dongjin Wu

    2016-06-01

    Full Text Available Location fingerprinting suffers in dynamic environments and needs recalibration from time to time to maintain system performance. This paper proposes an adaptive approach for location fingerprinting. Based on real-time received signal strength indicator (RSSI samples measured by a group of reference devices, the approach applies a modified Universal Kriging (UK interpolant to estimate adaptive temporal and environmental radio maps. The modified UK can take the spatial distribution characteristics of RSSI into account. In addition, the issue of device heterogeneity caused by multiple reference devices is further addressed. To compensate the measuring differences of heterogeneous reference devices, differential RSSI metric is employed. Extensive experiments were conducted in an indoor field and the results demonstrate that the proposed approach not only adapts to dynamic environments and the situation of changing APs’ positions, but it is also robust toward measuring differences of heterogeneous reference devices.

  16. 78 FR 34922 - Definition of Auditory Assistance Device

    Science.gov (United States)

    2013-06-11

    ... permitting such use of these devices would increase the comprehension of persons that need language... communications (including but not limited to applications such as assistive listening, auricular training, audio...

  17. Ethical Analysis of Withdrawing Ventricular Assist Device Support

    OpenAIRE

    Mueller, Paul S.; Swetz, Keith M.; Freeman, Monica R.; Carter, Kari A.; Crowley, Mary Eliot; Severson, Cathy J. Anderson; Park, Soon J.; Sulmasy, Daniel P.

    2010-01-01

    OBJECTIVE: To describe a series of patients with heart failure supported with a ventricular assist device (VAD) who requested (or whose surrogates requested) withdrawal of VAD support and the legal and ethical aspects pertaining to these requests.

  18. Introduction of assistive devices: home nurses' practices and beliefs.

    Science.gov (United States)

    Roelands, Marc; Van Oost, Paulette; Depoorter, Anne Marie; Buysse, Ann; Stevens, Veerle

    2006-04-01

    This paper reports a study describing home nurses' intention and current practices regarding introducing assistive devices, and investigating whether their practice is related to social cognitive factors (attitudes, subjective norms and self-efficacy). Home nurses not only care for patients in particular medical domains, but also educate and guide them towards more independence. Patients with age-related disabilities in mobility and self-care might benefit from the use of assistive devices. A home nurse might be the first and only person to discuss the disability and use of an assistive device. Therefore, home nurses' beliefs about the introduction of assistive devices could affect their daily practices. A cross-sectional study was conducted with a convenience sample of 64 home nurses chosen from a random sample of home nursing departments. The home nurses completed a self-administered questionnaire. The Theory of Planned Behaviour framework was used to develop the social cognitive measures regarding each of the six steps distinguished in the introduction of assistive devices. Home nurses had positive attitudes and high levels of intention, subjective norm and self-efficacy towards most steps of the decision process to introduce assistive devices. In a multiple linear regression analysis, attitude and self-efficacy predicted intention to introduce assistive devices to older clients with disabilities. Intention was correlated to home nurses' current practices. The findings suggest that conditions are present to involve home nurses more explicitly in the introduction of assistive devices to their patients. Social cognitive factors should be taken into account when developing interventions that aim to support home nurses to do this.

  19. Right heart failure due to loss of right ventricular capture in a patient with atrioventricular junction ablation and biventricular pacing.

    Science.gov (United States)

    Raffa, Santi; Fantoni, Cecilia; Restauri, Luigia; Auricchio, Angelo

    2005-10-01

    We describe the case of a patient with atrioventricular (AV) junction ablation and chronic biventricular pacing in which intermittent dysfunction of the right ventricular (RV) lead resulted in left ventricular (LV) stimulation alone and onset of severe right heart failure. Restoration of biventricular pacing by increasing device output and then performing lead revision resolved the issue. This case provides evidence that LV pacing alone in patients with AV junction ablation may lead to severe right heart failure, most likely as a result of iatrogenic mechanical dyssynchrony within the RV. Thus, probably this pacing mode should be avoided in pacemaker-dependent patients with heart failure.

  20. Human Grasp Assist Device With Exoskeleton

    Science.gov (United States)

    Bergelin, Bryan J (Inventor); Ihrke, Chris A. (Inventor); Davis, Donald R. (Inventor); Linn, Douglas Martin (Inventor); Bridgwater, Lyndon B. J. (Inventor)

    2014-01-01

    A grasp assist system includes a glove, actuator assembly, and controller. The glove includes a digit, i.e., a finger or thumb, and a force sensor. The sensor measures a grasping force applied to an object by an operator wearing the glove. Phalange rings are positioned with respect to the digit. A flexible tendon is connected at one end to one of the rings and is routed through the remaining rings. An exoskeleton positioned with respect to the digit includes hinged interconnecting members each connected to a corresponding ring, and/or a single piece of slotted material. The actuator assembly is connected to another end of the tendon. The controller calculates a tensile force in response to the measured grasping force, and commands the tensile force from the actuator assembly to thereby pull on the tendon. The exoskeleton offloads some of the tensile force from the operator's finger to the glove.

  1. A monitoring device for pressurised-air-driven diaphragm-based artificial heart assist devices

    NARCIS (Netherlands)

    Hoeben, F.P.; Hoeben, F.P.; de Mul, F.F.M.; Stokkink, J.S.D.; Stokkink, H.S.D.; Koelink, M.H.; Koelink, M.H.; Greve, Jan

    1992-01-01

    A non-invasive device has been developed to monitor the diaphragm position and the blood flow in artificial heart assist devices equipped with a pressurised-air-driven diaphragm. Light scattering from the diaphragm is used as a mechanism for measuring. Information about the position of several

  2. Vocational Reintegration of Handicapped Workers with Assistive Devices

    Science.gov (United States)

    Cooper, N. E.

    1977-01-01

    Two approaches to vocational reintegration of handicapped workers are described: (1) adapting the disabled to the working environment through treatment, therapy, counseling, selective placement, and prostheses, and (2) adapting the working environment to particular handicaps, with the assistive device fitted to the machine or tool rather than to…

  3. Monitoring mobility assistive device use in post-stroke patients

    DEFF Research Database (Denmark)

    Boissy, Patrice; Hester, Todd; Sherrill, Delsey

    2007-01-01

    Mobility assistive devices (MAD) such as canes can improve mobility and allow independence in the performance of mobility-related tasks. The use of MAD is often prescribed for stroke survivors. Despite their acknowledged qualities, MAD in real life conditions are typically underutilized, misused...

  4. Left Ventricular Assist Devices: The Adolescence of a Disruptive Technology.

    Science.gov (United States)

    Pinney, Sean P

    2015-10-01

    Clinical outcomes for patients with advanced heart failure receiving left ventricular assist devices are driven by appropriate patient selection, refined surgical technique, and coordinated medical care. Perhaps even more important is innovative pump design. The introduction and widespread adoption of continuous-flow ventricular assist devices has led to a paradigm shift within the field of mechanical circulatory support, making the promise of lifetime device therapy closer to reality. The disruption caused by this new technology, on the one hand, produced meaningful improvements in patient survival and quality of life, but also introduced new clinical challenges, such as bleeding, pump thrombosis, and acquired valvular heart disease. Further evolution within this field will require financial investment to sustain innovation leading to a fully implantable, durable, and cost-effective pump for a larger segment of patients with advanced heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Novel nonsurgical left ventricular assist device and system.

    Science.gov (United States)

    Misiri, Juna; DeSimone, Christopher V; Park, Soon J; Kushwaha, Sudhir S; Friedman, Paul A; Bruce, Charles J; Asirvatham, Samuel J

    2013-01-01

    Treatment options for advanced stages of congestive heart failure remain limited. Left ventricular assist devices (LVADs) have emerged as a means to support failing circulation. However, these devices are not without significant risk such as major open chest surgery. We utilized a novel approach for device placement at the aorto-left atria continuity as a site to create a conduit capable of accommodating a percutaneous LVAD system. We designed and developed an expandable nitinol based device for placement at this site to create a shunt between the LA and aorta. Our experiments support this anatomic location as an accessible and feasible site for accommodation of an entirely percutaneous LVAD. The novelty of this approach would bypass the left ventricle, and thereby minimize complications and morbidities associated with current LVAD placement. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Intraoperative bronchoscopic visualization of left ventricular assist device thrombus.

    Science.gov (United States)

    Yost, Gardner; Bhat, Geetha; Modi, Sejal; Pappas, Pat; Tatooles, Antone

    2016-07-01

    Despite advancements in left ventricular assist device (LVAD) design and clinical management, device thrombosis remains a pertinent complication. Limited imaging makes precise visualization of clot location and shape very challenging. We report the usage of videobronchoscopic exploration of explanted LVADs for direct visualization of clot in two patients. This technique is a rapid and inexpensive means of improving our understanding of LVAD clot formation and may be useful in surgical exploration of inflow and outflow tracts during LVAD exchange. © The Author(s) 2015.

  7. Modeling Users, Context and Devices for Ambient Assisted Living Environments

    Science.gov (United States)

    Castillejo, Eduardo; Almeida, Aitor; López-de-Ipiña, Diego; Chen, Liming

    2014-01-01

    The participation of users within AAL environments is increasing thanks to the capabilities of the current wearable devices. Furthermore, the significance of considering user's preferences, context conditions and device's capabilities help smart environments to personalize services and resources for them. Being aware of different characteristics of the entities participating in these situations is vital for reaching the main goals of the corresponding systems efficiently. To collect different information from these entities, it is necessary to design several formal models which help designers to organize and give some meaning to the gathered data. In this paper, we analyze several literature solutions for modeling users, context and devices considering different approaches in the Ambient Assisted Living domain. Besides, we remark different ongoing standardization works in this area. We also discuss the used techniques, modeled characteristics and the advantages and drawbacks of each approach to finally draw several conclusions about the reviewed works. PMID:24643006

  8. Network-Assisted Device-to-Device (D2D) Direct Proximity Discovery with Underlay Communication

    DEFF Research Database (Denmark)

    Pratas, Nuno; Popovski, Petar

    2015-01-01

    ) direct communication between proximate devices. While (ii) is treated extensively in the recent literature, (i) has received relatively little attention. In this paper we analyze a network-assisted underlay proximity discovery protocol, where a cellular device can take the role of: announcer (which......Device-to-Device communications are expected to play an important role in current and future cellular generations, by increasing the spatial reuse of spectrum resources and enabling lower latency communication links. This paradigm has two fundamental building blocks: (i) proximity discovery and (ii......, we consider the case where the announcers underlay their messages in the downlink transmissions that are directed towards the monitoring devices. We propose a power control scheme applied to the downlink transmission, which copes with the underlay transmission via additional power expenditure, while...

  9. Current Trends in Implantable Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Jens Garbade

    2011-01-01

    Full Text Available The shortage of appropriate donor organs and the expanding pool of patients waiting for heart transplantation have led to growing interest in alternative strategies, particularly in mechanical circulatory support. Improved results and the increased applicability and durability with left ventricular assist devices (LVADs have enhanced this treatment option available for end-stage heart failure patients. Moreover, outcome with newer pumps have evolved to destination therapy for such patients. Currently, results using nonpulsatile continuous flow pumps document the evolution in outcomes following destination therapy achieved subsequent to the landmark Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure Trial (REMATCH, as well as the outcome of pulsatile designed second-generation LVADs. This review describes the currently available types of LVADs, their clinical use and outcomes, and focuses on the patient selection process.

  10. Conventional radiography and computed tomography of cardiac assist devices

    Energy Technology Data Exchange (ETDEWEB)

    Scheffel, Hans; Stolzmann, Paul; Desbiolles, Lotus; Leschka, Sebastian; Frauenfelder, Thomas; Schertler, Thomas; Marincek, Borut; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Wilhelm, Markus J.; Lachat, Mario [University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland)

    2009-09-15

    Patients intended for circulatory support by cardiac assist devices (CAD) usually suffer from end-stage acute or chronic heart failure. Since the introduction of CAD in 1963 by DeBakey and coworkers, the systems have gone through a substantial evolution and have been increasingly used in the intervening decades. The spectrum of CAD includes a variety of systems serving to assist the systolic function of the left ventricle, the right ventricle, or both. Conventional radiography and multislice spiral computed tomography (CT) are the most commonly used radiological techniques for imaging patients with a CAD. CT is very useful for evaluating CAD systems by using both two- and three-dimensional reconstructions of the volumetric data sets. The two techniques together allow for the comprehensive assessment of patients with devices by imaging the in- and outflow cannulae, the anastomoses, the position of the pump, as well as associated complications. A close collaboration with cardiac surgeons with expertise in the field of circulatory support is deemed necessary for adequate image interpretation. This article describes the technical diversity of the currently available CAD systems. The imaging characteristics on conventional radiography and multislice spiral CT as well as the typical complications of their use are demonstrated. (orig.)

  11. Fiber Bragg grating sensor-based communication assistance device

    Science.gov (United States)

    Padma, Srivani; Umesh, Sharath; Pant, Shweta; Srinivas, Talabattula; Asokan, Sundarrajan

    2016-08-01

    Improvements in emergency medicine in the form of efficient life supporting systems and intensive care have increased the survival rate in critically injured patients; however, in some cases, severe brain and spinal cord injuries can result in a locked-in syndrome or other forms of paralysis, and communication with these patients may become restricted or impossible. The present study proposes a noninvasive, real-time communication assistive methodology for those with restricted communication ability, employing a fiber Bragg grating (FBG) sensor. The communication assistive methodology comprises a breath pattern analyzer using an FBG sensor, which acquires the exhalation force that is converted into strain variations on a cantilever. The FBG breath pattern analyzer along with specific breath patterns, which are programmed to give specific audio output commands, constitutes the proposed fiber Bragg grating sensor-based communication assistive device. The basic communication can be carried out by instructing the patients with restricted communication ability to perform the specific breath patterns. The present approach is intended to be an alternative to the common approach of brain-computer interface in which an instrument is utilized for learning of brain responses.

  12. An Implantable Intravascular Pressure Sensor for a Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Luigi Brancato

    2016-08-01

    Full Text Available The aim of this study is to investigate the intravascular application of a micro-electro-mechanical system (MEMS pressure sensor to directly measure the hemodynamic characteristics of a ventricular assist device (VAD. A bio- and hemo-compatible packaging strategy is implemented, based on a ceramic thick film process. A commercial sub-millimeter piezoresistive sensor is attached to an alumina substrate, and a double coating of polydimethylsiloxane (PDMS and parylene-C is applied. The final size of the packaged device is 2.6 mm by 3.6 mm by 1.8 mm. A prototype electronic circuit for conditioning and read-out of the pressure signal is developed, satisfying the VAD-specific requirements of low power consumption (less than 14.5 mW in continuous mode and small form factor. The packaged sensor has been submitted to extensive in vitro tests. The device displayed a temperature-independent sensitivity (12 μ V/V/mmHg and good in vitro stability when exposed to the continuous flow of saline solution (less than 0.05 mmHg/day drift after 50 h. During in vivo validation, the transducer has been successfully used to record the arterial pressure waveform of a female sheep. A small, intravascular sensor to continuously register the blood pressure at the inflow and the outflow of a VAD is developed and successfully validated in vivo.

  13. Accuracy of different imaging modalities prior to biventricular repair ...

    African Journals Online (AJOL)

    Arun Kumar Agnihotri

    catheterization with invasive angiocardiography is indicated when the PA ... arterial and venous imaging.3,4. The major ... history of aorto-pulmonary shunt awaiting bi-ventricular ..... regarding the central and peripheral PAs, APCs as well as in ...

  14. Bridge to transplantation with a left ventricular assist device.

    Science.gov (United States)

    Jung, Jae Jun; Sung, Kiick; Jeong, Dong Seop; Kim, Wook Sung; Lee, Young Tak; Park, Pyo Won

    2012-04-01

    A 61-year-old female patient was diagnosed with dilated cardiomyopathy with severe left ventricle dysfunction. Two days after admission, continuous renal replacement therapy was performed due to oliguria and lactic acidosis. On the fifth day, an intra-aortic balloon pump was inserted due to low cardiac output syndrome. Beginning 4 days after admission, she was supported for 15 days thereafter with an extracorporeal left ventricular assist device (LVAD) because of heart failure with multi-organ failure. A heart transplant was performed while the patient was stabilized with the LVAD. She developed several complications after the surgery, such as cytomegalovirus pneumonia, pulmonary tuberculosis, wound dehiscence, and H1N1 infection. On postoperative day 19, she was discharged from the hospital with close follow-up and treatment for infection. She received follow-up care for 10 months without any immune rejection reaction.

  15. Grasp Assist Device with Shared Tendon Actuator Assembly

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Bergelin, Bryan J. (Inventor); Bridgwater, Lyndon (Inventor)

    2015-01-01

    A grasp assist device includes a glove with first and second tendon-driven fingers, a tendon, and a sleeve with a shared tendon actuator assembly. Tendon ends are connected to the respective first and second fingers. The actuator assembly includes a drive assembly having a drive axis and a tendon hook. The tendon hook, which defines an arcuate surface slot, is linearly translatable along the drive axis via the drive assembly, e.g., a servo motor thereof. The flexible tendon is routed through the surface slot such that the surface slot divides the flexible tendon into two portions each terminating in a respective one of the first and second ends. The drive assembly may include a ball screw and nut. An end cap of the actuator assembly may define two channels through which the respective tendon portions pass. The servo motor may be positioned off-axis with respect to the drive axis.

  16. Memory-assisted measurement-device-independent quantum key distribution

    Science.gov (United States)

    Panayi, Christiana; Razavi, Mohsen; Ma, Xiongfeng; Lütkenhaus, Norbert

    2014-04-01

    A protocol with the potential of beating the existing distance records for conventional quantum key distribution (QKD) systems is proposed. It borrows ideas from quantum repeaters by using memories in the middle of the link, and that of measurement-device-independent QKD, which only requires optical source equipment at the user's end. For certain memories with short access times, our scheme allows a higher repetition rate than that of quantum repeaters with single-mode memories, thereby requiring lower coherence times. By accounting for various sources of nonideality, such as memory decoherence, dark counts, misalignment errors, and background noise, as well as timing issues with memories, we develop a mathematical framework within which we can compare QKD systems with and without memories. In particular, we show that with the state-of-the-art technology for quantum memories, it is potentially possible to devise memory-assisted QKD systems that, at certain distances of practical interest, outperform current QKD implementations.

  17. Inhaled Milrinone After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Haglund, Nicholas A; Burdorf, Adam; Jones, Tara; Shostrom, Valerie; Um, John; Ryan, Timothy; Shillcutt, Sasha; Fischer, Patricia; Cox, Zachary L; Raichlin, Eugenia; Anderson, Daniel R; Lowes, Brian D; Dumitru, Ioana

    2015-10-01

    Proven strategies to reduce right ventricular (RV) dysfunction after continuous-flow left ventricular assist device (CF-LVAD) implantation are lacking. We sought to evaluate the tolerability, feasibility, efficacy, and pharmacokinetics of inhaled milrinone (iMil) delivery after CF-LVAD implantation. We prospectively evaluated fixed-dose nebulized iMil delivered into a ventilator circuit for 24 hours in 10 postoperative CF-LVAD (Heartmate-II) patients. Tolerability (arrhythmias, hypotension, and hypersensitivity reaction), efficacy (hemodynamics), pharmacokinetics (plasma milrinone levels), and cost data were collected.Mean age was 56 ± 9 years, 90% were male, and mean INTERMACS profile was 2.5 ± 0.8. No new atrial arrhythmia events occurred, although 3 (30%) ventricular tachycardia (1 nonsustained, 2 sustained) events occurred. Sustained hypotension, drug hypersensitivity, death, or need for right ventricular assist device were not observed. Invasive mean pulmonary arterial pressure from baseline to during iMil therapy was improved (P = .017). Mean plasma milrinone levels (ng/mL) at baseline, and 1, 4, 8, 12, and 24 hours were 74.2 ± 35.4, 111.3 ± 70.9, 135.9 ± 41.5, 205.0 ± 86.7, 176.8 ± 61.3 187.6 ± 105.5, respectively. Reduced institutional cost was observed when iMil was compared with nitric oxide therapy over 24 hours ($165.29 vs $1,944.00, respectively). iMil delivery after CF-LVAD implantation was well tolerated, feasible, and demonstrated favorable hemodynamic, pharmacokinetic, and cost profiles. iMil therapy warrants further study in larger clinical trials. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Our experience with implantation of VentrAssist left ventricular assist device

    Directory of Open Access Journals (Sweden)

    Hiriyur Shivalingappa Jayanthkumar

    2013-01-01

    Full Text Available Perioperative anaesthetic management of the VentrAssist TM left ventricular assist device (LVAD is a challenge for anaesthesiologists because patients presenting for this operation have long-standing cardiac failure and often have associated hepatic and renal impairment, which may significantly alter the pharmacokinetics of administered drugs and render the patients coagulopathic. The VentrAssist is implanted by midline sternotomy. A brief period of cardiopulmonary bypass (CPB for apical cannulation of left ventricle is needed. The centrifugal pump, which produces non-pulsatile, continuous flow, is positioned in the left sub-diaphragmatic pocket. This LVAD is preload dependent and afterload sensitive. Transoesophageal echocardiography is an essential tool to rule out contraindications and to ensure proper inflow cannula position, and following the implantation of LVAD, to ensure right ventricular (RV function. The anaesthesiologist should be prepared to manage cardiac decompensation and acute desaturation before initiation of CPB, as well as RV failure and severe coagulopathic bleeding after CPB. Three patients had undergone implantation of VentrAssist in our hospital. This pump provides flow of 5 l/min depending on preload, afterload and pump speed. All the patients were discharged after an average of 30 days. There was no perioperative mortality.

  19. Development of Hand Grip Assistive Device Control System for Old People through Electromyography (EMG) Signal Acquisitions

    OpenAIRE

    Khamis Herman; Mohamaddan Shahrol; Komeda Takashi; Alias Aidil Azli; Tanjong Shirley Jonathan; Julai Norhuzaimin; Hashim Nurul ‘Izzati

    2017-01-01

    The hand grip assistive device is a glove to assist old people who suffer from hand weakness in their daily life activities. The device earlier control system only use simple on and off switch. This required old people to use both hand to activate the device. The new control system of the hand grip assistive device was developed to allow single hand operation for old people. New control system take advantages of electromyography (EMG) and flex sensor which was implemented to the device. It wa...

  20. Integrating medical, assistive, and universally designed products and technologies: assistive technology device classification (ATDC).

    Science.gov (United States)

    Bauer, Stephen; Elsaesser, Linda-Jeanne

    2012-09-01

    ISO26000:2010 International Guidance Standard on Organizational Social Responsibility requires that effective organizational performance recognize social responsibility, including the rights of persons with disabilities (PWD), engage stakeholders and contribute to sustainable development. Millennium Development Goals 2010 notes that the most vulnerable people require special attention, while the World Report on Disability 2011 identifies improved data collection and removal of barriers to rehabilitation as the means to empower PWD. The Assistive Technology Device Classification (ATDC), Assistive Technology Service Method (ATSM) and Matching Person and Technology models provide an evidence-based, standardized, internationally comparable framework to improve data collection and rehabilitation interventions. The ATDC and ATSM encompass and support universal design (UD) principles, and use the language and concepts of the International Classification of Functioning, Disability and Health (ICF). Use ATDC and ICF concepts to differentiate medical, assistive and UD products and technology; relate technology "types" to markets and costs; and support provision of UD products and technologies as sustainable and socially responsible behavior. Supply-side and demand-side incentives are suggested to foster private sector development and commercialization of UD products and technologies. Health and health-related professionals should be knowledgeable of UD principles and interventions.

  1. Biventricular thrombus in hypereosinophilic syndrome presenting with shortness of breath

    Directory of Open Access Journals (Sweden)

    Abdul Baqi

    2016-06-01

    Full Text Available A 48 years old male presented to clinic with 12 months of low grade fever with shortness of breath which has progressively worsened with no associated weight loss, night sweats or loss of appetite. There was no prior history of chronic illness before the current illness. Laboratory workup revealed a high white blood cell count with predominant eosinophils. Chest X-ray was normal. Transthoracic echocardiography and Cardiac Magnetic Resonance showed biventricular thrombi. On further extensive workup the findings were consistent with hypereosinophilic syndrome. The patient was started on oral steroids, hydroxyurea, imatanib mesylate and oral anticoagulation. The patient responded to the treatment with complete resolution of his symptoms over the course of few months. The repeat Echocardiogram after a year showed normal left ventricular systolic and diastolic function with complete resolution of biventricular thrombi. Keywords: Hypereosinophilic syndrome, Thrombus

  2. Left ventricular assist device exchange: the Toronto General Hospital experience.

    Science.gov (United States)

    Tsubota, Hideki; Ribeiro, Roberto V P; Billia, Filio; Cusimano, Robert J; Yau, Terrence M; Badiwala, Mitesh V; Stansfield, William E; Rao, Vivek

    2017-08-01

    As support times for left ventricular assist devices (LVADs) become longer, several complications requiring device exchange may occur. To our knowledge, this is the first Canadian report regarding implantable LVAD exchange. We retrospectively reviewed the cases of consecutive, unique patients implanted with an LVAD between June 2006 and October 2015 at Toronto General Hospital. In total, 122 patients were impanted with an LVAD during the study period. Eight patients required LVAD exchange, and 1 patient had 2 replacements (9 of 122, 7.3%). There were 7 HeartMate II (HMII), 1 HVAD and 1 DuraHeart pumps exchanged. Two of these exchanges occurred early at the time of initial implant, whereas 7 occurred late (range 8-623 d). Six exchanges were made owing to pump thrombosis. Of the 3 exchanges made for other causes, 1 HMII exchange was owing to a driveline fracture, 1 DuraHeart patient had early inflow obstruction requiring exchange to HMII at the initial implant, and the third had a suspected inflow obstruction with no evidence of thrombosis at the time of the procedure. The mean support time before exchange was 225 days, and time from exchange to transplant, death or ongoing support was 245 days. Three patients were successfully bridged to transplant, and at the time of data collection 2 were supported awaiting transplant. Three patients died after a mean duration of 394.3 days (range 78-673 d) of support postreplacement. Four cases were successfully performed using a subcostal approach. Pump thrombosis is the most common cause for LVAD exchange, which can be performed with acceptable morbidity and mortality. The subcostal approach may be the preferred procedure for an HMII exchange when indicated.

  3. Stroke Risk and Mortality in Patients With Ventricular Assist Devices.

    Science.gov (United States)

    Parikh, Neal S; Cool, Joséphine; Karas, Maria G; Boehme, Amelia K; Kamel, Hooman

    2016-11-01

    Ventricular assist devices (VADs) have advanced the management of end-stage heart failure. However, these devices are associated with hemorrhagic and thrombotic complications, including stroke. We assessed the incidence, risk factors, and outcomes of ischemic and hemorrhagic stroke after VAD placement. Using administrative claims data from acute care hospitals in California, Florida, and New York from 2005 to 2013, we identified patients who underwent VAD placement, defined by the International Classification of Diseases, Ninth Revision, Clinical Modification code 37.66. Ischemic and hemorrhagic strokes were identified by previously validated coding algorithms. We used survival statistics to determine the incidence rates and Cox proportional hazard analyses to examine the associations. Among 1813 patients, we identified 201 ischemic strokes and 116 hemorrhagic strokes during 3.4 (±2.0) years of follow-up after implantation of a VAD. The incidence of stroke was 8.7% per year (95% confidence interval [CI], 7.7-9.7). The annual incidence of ischemic stroke (5.5%; 95% CI, 4.8-6.4) was nearly double that of hemorrhagic stroke (3.1%; 95% CI, 2.6-3.8). Women faced a higher hazard of stroke than men (hazard ratio, 1.6; 95% CI, 1.2-2.1), particularly hemorrhagic stroke (hazard ratio, 2.2; 95% CI, 1.4-3.4). Stroke was strongly associated with subsequent in-hospital mortality (hazard ratio, 6.1; 95% CI, 4.6-7.9). The incidence of stroke after VAD implantation was 8.7% per year, and incident stroke was strongly associated with subsequent in-hospital mortality. Notably, ischemic stroke occurred at nearly twice the rate of hemorrhagic stroke. Women seemed to face a higher risk for hemorrhagic stroke than men. © 2016 American Heart Association, Inc.

  4. Ergonomic evaluation of a wearable assistive device for overhead work.

    Science.gov (United States)

    Rashedi, Ehsan; Kim, Sunwook; Nussbaum, Maury A; Agnew, Michael J

    2014-01-01

    Overhead work is an important risk factor for upper extremity (UE) musculoskeletal disorders. We examined the potential of a mechanical arm and an exoskeletal vest as a wearable assistive device (WADE) for overhead work. Twelve participants completed 10 minutes of simulated, intermittent overhead work, using each of three payloads (1.1, 3.4 and 8.1 kg) and with/without the WADE. Ratings of perceived discomfort (RPDs) and electromyography (EMG) were obtained for the upper arms, shoulders and low back. Using the WADE, UE RPDs decreased by ∼50% with the heavier payloads, whereas smaller (∼25%) and non-significant increases in low-back RPDs were found and were relatively independent of payload. Changes in RPDs with WADE use were consistent with physical demands indicated by EMG, though EMG-based differences in fatigue were less apparent. Participants generally preferred using the WADE, particularly with heavier payloads. These results supported the potential utility of a WADE as an intervention for overhead work.

  5. Memory-assisted measurement-device-independent quantum key distribution

    International Nuclear Information System (INIS)

    Panayi, Christiana; Razavi, Mohsen; Ma, Xiongfeng; Lütkenhaus, Norbert

    2014-01-01

    A protocol with the potential of beating the existing distance records for conventional quantum key distribution (QKD) systems is proposed. It borrows ideas from quantum repeaters by using memories in the middle of the link, and that of measurement-device-independent QKD, which only requires optical source equipment at the user's end. For certain memories with short access times, our scheme allows a higher repetition rate than that of quantum repeaters with single-mode memories, thereby requiring lower coherence times. By accounting for various sources of nonideality, such as memory decoherence, dark counts, misalignment errors, and background noise, as well as timing issues with memories, we develop a mathematical framework within which we can compare QKD systems with and without memories. In particular, we show that with the state-of-the-art technology for quantum memories, it is potentially possible to devise memory-assisted QKD systems that, at certain distances of practical interest, outperform current QKD implementations. (paper)

  6. Comparison of Transplant Waitlist Outcomes for Pediatric Candidates Supported by Ventricular Assist Devices Versus Medical Therapy.

    Science.gov (United States)

    Law, Sabrina P; Oron, Assaf P; Kemna, Mariska S; Albers, Erin L; McMullan, D Michael; Chen, Jonathan M; Law, Yuk M

    2018-05-01

    Ventricular assist devices have gained popularity in the management of refractory heart failure in children listed for heart transplantation. Our primary aim was to compare the composite endpoint of all-cause pretransplant mortality and loss of transplant eligibility in children who were treated with a ventricular assist device versus a medically managed cohort. This was a retrospective cohort analysis. Data were obtained from the Scientific Registry of Transplant Recipients. The at-risk population (n = 1,380) was less than 18 years old, either on a ventricular assist device (605 cases) or an equivalent-severity, intensively medically treated group (referred to as MED, 775 cases). None. The impact of ventricular assist devices was estimated via Cox proportional hazards regression (hazard ratio), dichotomizing 1-year outcomes to "poor" (22%: 193 deaths, 114 too sick) versus all others (940 successful transplants, 41 too healthy, 90 censored), while adjusting for conventional risk factors. Among children 0-12 months old, ventricular assist device was associated with a higher risk of poor outcomes (hazard ratio, 2.1; 95% CI, 1.5-3.0; p comparative study of ventricular assist devices versus medical therapy in children. Age is a significant modulator of waitlist outcomes for children with end-stage heart failure supported by ventricular assist device, with the impact of ventricular assist devices being more beneficial in adolescents.

  7. A novel implantable electromechanical ventricular assist device - First acute animal testing

    NARCIS (Netherlands)

    Kaufmann, R; Rakhorst, G; Mihaylov, D; Elstrodt, J; Nix, C; Reul, H; Rau, G

    1997-01-01

    A novel ventricular assist device (HIA-EMLVAD-AT1, Helmholtz Institute Aachen-electromechanical Left Ventricular Assist Device-Animal Test Version 1), driven by a uniformly and unidirectionally rotating actuator and a patented hypocycloidic pusherplate displacement gear unit, was developed and

  8. Internet-Based Device-Assisted Remote Monitoring of Cardiovascular Implantable Electronic Devices

    Science.gov (United States)

    Pron, G; Ieraci, L; Kaulback, K

    2012-01-01

    Executive Summary Objective The objective of this Medical Advisory Secretariat (MAS) report was to conduct a systematic review of the available published evidence on the safety, effectiveness, and cost-effectiveness of Internet-based device-assisted remote monitoring systems (RMSs) for therapeutic cardiac implantable electronic devices (CIEDs) such as pacemakers (PMs), implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices. The MAS evidence-based review was performed to support public financing decisions. Clinical Need: Condition and Target Population Sudden cardiac death (SCD) is a major cause of fatalities in developed countries. In the United States almost half a million people die of SCD annually, resulting in more deaths than stroke, lung cancer, breast cancer, and AIDS combined. In Canada each year more than 40,000 people die from a cardiovascular related cause; approximately half of these deaths are attributable to SCD. Most cases of SCD occur in the general population typically in those without a known history of heart disease. Most SCDs are caused by cardiac arrhythmia, an abnormal heart rhythm caused by malfunctions of the heart’s electrical system. Up to half of patients with significant heart failure (HF) also have advanced conduction abnormalities. Cardiac arrhythmias are managed by a variety of drugs, ablative procedures, and therapeutic CIEDs. The range of CIEDs includes pacemakers (PMs), implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices. Bradycardia is the main indication for PMs and individuals at high risk for SCD are often treated by ICDs. Heart failure (HF) is also a significant health problem and is the most frequent cause of hospitalization in those over 65 years of age. Patients with moderate to severe HF may also have cardiac arrhythmias, although the cause may be related more to heart pump or haemodynamic failure. The presence of HF, however

  9. Ethical challenges with the left ventricular assist device as a destination therapy

    Directory of Open Access Journals (Sweden)

    Rady Mohamed Y

    2008-08-01

    Full Text Available Abstract The left ventricular assist device was originally designed to be surgically implanted as a bridge to transplantation for patients with chronic end-stage heart failure. On the basis of the REMATCH trial, the US Food and Drug Administration and the US Centers for Medicare & Medicaid Services approved permanent implantation of the left ventricular assist device as a destination therapy in Medicare beneficiaries who are not candidates for heart transplantation. The use of the left ventricular assist device as a destination therapy raises certain ethical challenges. Left ventricular assist devices can prolong the survival of average recipients compared with optimal medical management of chronic end-stage heart failure. However, the overall quality of life can be adversely affected in some recipients because of serious infections, neurologic complications, and device malfunction. Left ventricular assist devices alter end-of-life trajectories. The caregivers of recipients may experience significant burden (e.g., poor physical health, depression, anxiety, and posttraumatic stress disorder from destination therapy with left ventricular assist devices. There are also social and financial ramifications for recipients and their families. We advocate early utilization of a palliative care approach and outline prerequisite conditions so that consenting for the use of a left ventricular assist device as a destination therapy is a well informed process. These conditions include: (1 direct participation of a multidisciplinary care team, including palliative care specialists, (2 a concise plan of care for anticipated device-related complications, (3 careful surveillance and counseling for caregiver burden, (4 advance-care planning for anticipated end-of-life trajectories and timing of device deactivation, and (5 a plan to address the long-term financial burden on patients, families, and caregivers. Short-term mechanical circulatory devices (e

  10. Translation and validation of the assistive technology device predisposition assessment in Greek in order to assess satisfaction with use of the selected assistive device.

    Science.gov (United States)

    Koumpouros, Yiannis; Papageorgiou, Effie; Karavasili, Alexandra; Alexopoulou, Despoina

    2017-07-01

    To examine the Assistive Technology Device Predisposition Assessment scale and provide evidence of validity and reliability of the Greek version. We translated and adapted the original instrument in Greek according to the most well-known guidelines recommendations. Field test studies were conducted in a rehabilitation hospital to validate the appropriateness of the final results. Ratings of the different items were statistically analyzed. We recruited 115 subjects who were administered the Form E of the original questionnaire. The experimental analysis conducted revealed a three subscales structure: (i) Adaptability, (ii) Fit to Use, and (iii) Socializing. According to the results of our study the three subscales measure different constructs. Reliability measures (ICC = 0.981, Pearson's correlation = 0.963, Cronbach's α = 0.701) yielded high values. Test-retest outcome showed great stability. This is the first study, at least to the knowledge of the authors, which focuses merely on measuring the satisfaction of the users from the used assistive device, while exploring the Assistive Technology Device Predisposition Assessment - Device Form in such depth. According to the results, it is a stable, valid and reliable instrument and applicable to the Greek population. Thus, it can be used to measure the satisfaction of patients with assistive devices. Implications for Rehabilitation The paper explores the cultural adaptability and applicability of ATD PA - Device Form. ATD PA - Device Form can be used to assess user satisfaction by the selected assistive device. ATD PA - Device Form is a valid and reliable instrument in measuring users' satisfaction in Greekreality.

  11. Left ventricular assist device (lvad design features: literature review

    Directory of Open Access Journals (Sweden)

    Yu. V. Bogdanova

    2014-01-01

    Full Text Available More than 8 million people in our country suffer from heart failure. About one million of these people die each year [1]. The problem of ventricular assist device creating - a mechanical device used for partial or complete replacement of heart function - is investigated for a long time (according to [2] just in our country since the 1970s. Today plenty of encouraging results are received. There is a number of VAD models which are successfully applied to patients with heart failure. After implantation, patients conduct a way of life that is normal in many respects: they are in the family, often they have an opportunity to work in their former specialty. Some of them live with the device about 8 years [3].According to [4] for 2010 the estimated total number of long-term devices implanted in the United States per year is over 1,700 (the population of the U.S. is 305 million, compared with over 430 per year in Europe (the population of Europe is 731 million. Unfortunately, people who need a heart transplant are much more.The principle of VAD is that being connected to the left ventricle with one cannula and to the ascending aorta with the other cannula the pump fully or partially replaces the function of the natural heart. This scheme allows the use of VAD in two ways: as a "bridge to transplantation" when the device is used temporarily until the donor heart is found, and a "bridge to recovery", when through the use of VAD the function of the heart muscle is recovered.VAD system can be divided into three subsystems: blood pump, power supply system and control system (Fig. 1.Each subsystem can be the subject of separate study. Special role in the development of VAD plays medical side of the issue. Successful research and development require interaction with qualified professionals in this field. The development of VAD is a multidisciplinary problem which demands fulfilment of a number of requirements.One of the most active programs in implantation of

  12. Right ventricular functional analysis utilizing first pass radionuclide angiography for pre-operative ventricular assist device planning: a multi-modality comparison.

    Science.gov (United States)

    Avery, Ryan; Day, Kevin; Jokerst, Clinton; Kazui, Toshinobu; Krupinski, Elizabeth; Khalpey, Zain

    2017-10-10

    FPRNA was 32.6% (9 - 56%). The mean discrepancy for LVEF between cardiac MRI and MUGA was 4.1% (0 - 9%), and correlation of calculated LVEF using cardiac MRI and MUGA demonstrated an R of 0.9. The mean discrepancy for RVEF between cardiac MRI and FPRNA was 12.0% (range: 2 - 24%) with a moderate correlation (R = 0.5). The increased discrepancies for RV analysis were statistically significant using an unpaired t-test (t = 3.19, p = 0.0061). Echocardiogram parameters of RV function, including TAPSE and FAC, were for available for all 9 patients and agreement with cardiac MRI demonstrated a kappa statistic for TAPSE of 0.39 (95% CI of 0.06 - 0.72) and for FAC of 0.64 (95% of 0.21 - 1.00). Heart failure patients are increasingly requiring left ventricular assist device placement; however, definitive evaluation of biventricular function is required due to the increased mortality rate associated with right heart failure after assist device placement. Our results suggest that FPRNA only has a moderate correlation with reference standard RVEFs calculated using cardiac MRI, which was similar to calculated agreements between cardiac MRI and echocardiographic parameters of right ventricular function. Given the need for identification of patients at risk for right heart failure, further studies are warranted to determine a more accurate estimate of RVEF for heart failure patients during pre-operative ventricular assist device planning.

  13. Percutaneous Repair of Postoperative Mitral Regurgitation After Left Ventricular Assist Device Implant.

    Science.gov (United States)

    Cork, David P; Adamson, Robert; Gollapudi, Raghava; Dembitsky, Walter; Jaski, Brian

    2018-02-01

    Mitral regurgitation commonly improves after implantation of a left ventricular assist device without concomitant valvular repair owing to the mechanical unloading of the left ventricle. However, the development (or persistence) of significant mitral regurgitation after implantation of a left ventricular assist device is associated with adverse clinical events. We present a case of a left ventricular assist device patient who successfully underwent a percutaneous MitraClip procedure for repair of persistent late postoperative mitral insufficiency with demonstrable clinical and hemodynamic improvement. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Grasp Assist Device with Automatic Mode Control Logic

    Science.gov (United States)

    Davis, Donald R. (Inventor); Ihrke, Chris A. (Inventor); Laske, Evan (Inventor)

    2018-01-01

    A system includes a glove, sensors, actuator assemblies, and controller. The sensors include load sensors which measure an actual grasping force and attitude sensors which determine a glove attitude. The actuator assembly provides a grasp assist force to the glove. Respective locations of work cells in the work environment and permitted work tasks for each work cell are programmed into the controller. The controller detects the glove location and attitude. A work task is selected by the controller for the location. The controller calculates a required grasp assist force using measured actual grasping forces from the load sensors. The required grasp assist force is applied via the glove using the actuator assembly to thereby assist the operator in performing the identified work task.

  15. Ethical framework of assistive devices: review and reflection

    OpenAIRE

    Mansouri, Nazanin; Goher, Khaled; Hosseini, Seyed Ebrahim

    2017-01-01

    The population of ageing is growing significantly over the world, and there is an emerging demand for better healthcare services and more care centres. Innovations of Information and Communication Technology has resulted in development of various types of assistive robots to fulfil elderly’s needs and independency, whilst carrying out daily routine tasks. This makes it vital to have a clear understanding of elderly’s needs and expectations from assistive robots. This paper addresses current e...

  16. Durability of central aortic valve closure in patients with continuous flow left ventricular assist devices.

    Science.gov (United States)

    McKellar, Stephen H; Deo, Salil; Daly, Richard C; Durham, Lucian A; Joyce, Lyle D; Stulak, John M; Park, Soon J

    2014-01-01

    A competent aortic valve is essential to providing effective left ventricular assist device support. We have adopted a practice of central aortic valve closure by placing a simple coaptation stitch at left ventricular assist device implantation in patients with significant aortic insufficiency. We conducted a follow-up study to evaluate the efficacy and durability of this procedure. The study included patients who had undergone continuous flow left ventricular assist device implantation. The patients were divided into 2 groups, those who did not require any aortic procedure because the valve was competent and those who underwent central aortic valve closure for mild or greater aortic regurgitation. The clinical endpoints were mortality, progression or recurrence of aortic insufficiency, and reoperation for aortic valve pathologic features. Aortic insufficiency was measured qualitatively from mild to severe on a scale of 0 to 5. A total of 123 patients received continuous flow left ventricular assist devices from February 2007 to August 2011. Of those, 18 (15%) underwent central aortic valve closure at left ventricular assist device implantation because of significant aortic insufficiency (1.8 ± 1.4) and 105 who did not (competent aortic valve, 0.15 ± 0.43; P assist device-supported patients, with follow-up extending into 2 years. Although aortic insufficiency progressed over time in those with minimal native valve regurgitation initially, no such progression was noted in those with central aortic valve closure. Additional investigation is needed to evaluate whether prophylactic central aortic valve closure should be performed at left ventricular assist device implantation to avoid problematic aortic regurgitation developing over time, in particular in patients undergoing left ventricular assist device implantation for life-long (destination therapy) support. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights

  17. Left ventricular assist device as destination therapy: application of the payment-by-results approach for the device reimbursement.

    Science.gov (United States)

    Messori, Andrea; Trippoli, Sabrina; Bonacchi, Massimo; Sani, Guido

    2009-08-01

    Value-based methods are increasingly used to reimburse therapeutic innovation, and the payment-by-results approach has been proposed for handling interventions with limited therapeutic evidence. Because most left ventricular assist devices are supported by preliminary efficacy data, we examined the effectiveness data of the HeartMate (Thoratec Corp, Pleasanton, CA) device to explore the application of the payment-by-results approach to these devices and to develop a model for handling reimbursements. According to our model, after establishing the societal economic countervalue for each month of life saved, each patient treated with one such device is associated to the payment of this countervalue for every month of survival lived beyond the final date of estimated life expectancy without left ventricular assist devices. Our base-case analysis, which used the published data of 68 patients who received the HeartMate device, was run with a monthly countervalue of euro 5000, no adjustment for quality of life, and a baseline life expectancy of 150 days without left ventricular assist devices. Sensitivity analysis was aimed at testing the effect of quality of life adjustments and changes in life expectancy without device. In our base-case analysis, the mean total reimbursement per patient was euro 82,426 (range, euro 0 to euro 250,000; N = 68) generated as the sum of monthly payments. This average value was close to the current price of the HeartMate device (euro 75,000). Sensitivity testing showed that the base-case reimbursement of euro 82,426 was little influenced by variations in life expectancy, whereas variations in utility had a more pronounced impact. Our report delineates an innovative procedure for appropriately allocating economic resources in this area of invasive cardiology.

  18. Analysis of Contemporary Methods for Designing Rotary Type Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    E. P. Banin

    2015-01-01

    Full Text Available The research object is inlet apparatus of ventricular assist device, namely inlet cannula and straightener.The purpose of the study is to reveal features of blood flow in inlet apparatus of ventricular assist device. The mathematical modeling is carried out by computational fluid dynamics analysis in a stationary setting.The first part of study concerns the analysis of existing approaches to the numerical and experimental studies in designing the ventricular assist devices of rotary type. It reveals the features of each approach for their further application in practice. The article presents an original design of developed hydraulic test bench to verify the results of mathematical modeling. Analysis of foreign authors’ studies showed that there is no enough attention paid to design of the adjacent pump assemblies of ventricular assist device. The second part of study considers direct mathematical modeling of input apparatus of ventricular assist device. The study examined straightener with three or four blades. Mathematical modeling has revealed the presence of potentially dangerous stagnation zones and essential asymmetry of the outlet flow from the input unit. The found features must be taken in consideration in designing the ventricular assist device pumps. In the future we plan to use obtained data to create a parametric model of the rotor and the diffuser considering the abovementioned features.

  19. Impact of interface charge on the electrostatics of field-plate assisted RESURF devices

    NARCIS (Netherlands)

    Boksteen, B.K.; Ferrara, A.; Heringa, A.; Steeneken, P.G.; Hueting, Raymond Josephus Engelbart

    2014-01-01

    A systematic study on the effects of arbitrary parasitic charge profiles, such as trapped or fixed charge, on the 2-D potential distribution in the drain extension of reverse-biased field-plate-assisted reduced surface field (RESURF) devices is presented. Using TCAD device simulations and analytical

  20. Magnet-assisted device-level alignment for the fabrication of membrane-sandwiched polydimethylsiloxane microfluidic devices

    International Nuclear Information System (INIS)

    Lu, J-C; Liao, W-H; Tung, Y-C

    2012-01-01

    Polydimethylsiloxane (PDMS) microfluidic device is one of the most essential techniques that advance microfluidics research in recent decades. PDMS is broadly exploited to construct microfluidic devices due to its unique and advantageous material properties. To realize more functionalities, PDMS microfluidic devices with multi-layer architectures, especially those with sandwiched membranes, have been developed for various applications. However, existing alignment methods for device fabrication are mainly based on manual observations, which are time consuming, inaccurate and inconsistent. This paper develops a magnet-assisted alignment method to enhance device-level alignment accuracy and precision without complicated fabrication processes. In the developed alignment method, magnets are embedded into PDMS layers at the corners of the device. The paired magnets are arranged in symmetric positions at each PDMS layer, and the magnetic attraction force automatically pulls the PDMS layers into the aligned position during assembly. This paper also applies the method to construct a practical microfluidic device, a tunable chaotic micromixer. The results demonstrate the successful operation of the device without failure, which suggests the accurate alignment and reliable bonding achieved by the method. Consequently, the fabrication method developed in this paper is promising to be exploited to construct various membrane-sandwiched PDMS microfluidic devices with more integrated functionalities to advance microfluidics research. (paper)

  1. De novo development of eosinophilic myocarditis with left ventricular assist device support as bridge to transplant.

    Science.gov (United States)

    Pereira, Naveen L; Park, Soon J; Daly, Richard C; Kushwaha, Sudhir S; Edwards, William D

    2010-10-01

    The de novo development of myocarditis during left ventricular assist device support for dilated cardiomyopathy has not been previously described. We report a case of severe eosinophilic myocarditis associated with the use of leukotriene-receptor antagonist montelukast that developed during left ventricular assist device support accompanied by intra-device thrombus formation that was hemodynamically tolerated and subsequently discovered in the explanted heart. There may be no visible change in cardiac function as assessed by echocardiography, but the diagnosis should be entertained with the development of peripheral eosinophilia. Copyright © 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  2. User assistance for multitasking with interruptions on a mobile device

    NARCIS (Netherlands)

    Nagata, S.F.

    2006-01-01

    Issues users have with use of the web on a mobile device can be attributed to difficulties with the mobile interface. A major challenge that we address is improving the user experience for handling of interruptions and multitasking when using the web in a mobile context. The usability issues with a

  3. User Assistance for Multitasking with Interruptions on a Mobile Device

    NARCIS (Netherlands)

    Nagata, S.F.

    2006-01-01

    Issues users have with use of the web on a mobile device can be attributed to difficulties with the mobile interface. A major challenge that we address is improving the user experience for handling of interruptions and multitasking when using the web in a mobile context. The usability issues with a

  4. Ethical framework of assistive devices: review and reflection.

    Science.gov (United States)

    Mansouri, Nazanin; Goher, Khaled; Hosseini, Seyed Ebrahim

    2017-01-01

    The population of ageing is growing significantly over the world, and there is an emerging demand for better healthcare services and more care centres. Innovations of Information and Communication Technology has resulted in development of various types of assistive robots to fulfil elderly's needs and independency, whilst carrying out daily routine tasks. This makes it vital to have a clear understanding of elderly's needs and expectations from assistive robots. This paper addresses current ethical issues to understand elderly's prime needs. Also, we consider other general ethics with the purpose of applying these theories to form a proper ethics framework. In the ethics framework, the ethical concerns of senior citizens will be prioritized to satisfy elderly's needs and also to diminish related expenses to healthcare services.

  5. VENTRICLE ASSIST DEVICE: PAST, PRESENT, AND FUTURE NONPULSATILE PUMPS

    Directory of Open Access Journals (Sweden)

    G. Р. Itkin

    2009-01-01

    Full Text Available The article briefly describes the history of the non-pulsating type blood pumps for ventricular assist circulation and heart-lung machine. Disclosed the main advantages of these pumps before pulsating type, especially for implantable systems development. However, disadvantages of these pumps and the directions of minimize or eliminate ones have shown. Specific examples of our implantable centrifugal and axial pump developments are presented. Declare the ways to further improve the pumps. 

  6. Stretchable Materials for Robust Soft Actuators towards Assistive Wearable Devices

    Science.gov (United States)

    Agarwal, Gunjan; Besuchet, Nicolas; Audergon, Basile; Paik, Jamie

    2016-09-01

    Soft actuators made from elastomeric active materials can find widespread potential implementation in a variety of applications ranging from assistive wearable technologies targeted at biomedical rehabilitation or assistance with activities of daily living, bioinspired and biomimetic systems, to gripping and manipulating fragile objects, and adaptable locomotion. In this manuscript, we propose a novel two-component soft actuator design and design tool that produces actuators targeted towards these applications with enhanced mechanical performance and manufacturability. Our numerical models developed using the finite element method can predict the actuator behavior at large mechanical strains to allow efficient design iterations for system optimization. Based on two distinctive actuator prototypes’ (linear and bending actuators) experimental results that include free displacement and blocked-forces, we have validated the efficacy of the numerical models. The presented extensive investigation of mechanical performance for soft actuators with varying geometric parameters demonstrates the practical application of the design tool, and the robustness of the actuator hardware design, towards diverse soft robotic systems for a wide set of assistive wearable technologies, including replicating the motion of several parts of the human body.

  7. Modelling Framework and Assistive Device for Peripheral Intravenous Injections

    Science.gov (United States)

    Kam, Kin F.; Robinson, Martin P.; Gilbert, Mathew A.; Pelah, Adar

    2016-02-01

    Intravenous access for blood sampling or drug administration that requires peripheral venepuncture is perhaps the most common invasive procedure practiced in hospitals, clinics and general practice surgeries.We describe an idealised mathematical framework for modelling the dynamics of the peripheral venepuncture process. Basic assumptions of the model are confirmed through motion analysis of needle trajectories during venepuncture, taken from video recordings of a skilled practitioner injecting into a practice kit. The framework is also applied to the design and construction of a proposed device for accurate needle guidance during venepuncture administration, assessed as consistent and repeatable in application and does not lead to over puncture. The study provides insights into the ubiquitous peripheral venepuncture process and may contribute to applications in training and in the design of new devices, including for use in robotic automation.

  8. Towards automated assistance for operating home medical devices.

    Science.gov (United States)

    Gao, Zan; Detyniecki, Marcin; Chen, Ming-Yu; Wu, Wen; Hauptmann, Alexander G; Wactlar, Howard D

    2010-01-01

    To detect errors when subjects operate a home medical device, we observe them with multiple cameras. We then perform action recognition with a robust approach to recognize action information based on explicitly encoding motion information. This algorithm detects interest points and encodes not only their local appearance but also explicitly models local motion. Our goal is to recognize individual human actions in the operations of a home medical device to see if the patient has correctly performed the required actions in the prescribed sequence. Using a specific infusion pump as a test case, requiring 22 operation steps from 6 action classes, our best classifier selects high likelihood action estimates from 4 available cameras, to obtain an average class recognition rate of 69%.

  9. Development of Hand Grip Assistive Device Control System for Old People through Electromyography (EMG Signal Acquisitions

    Directory of Open Access Journals (Sweden)

    Khamis Herman

    2017-01-01

    Full Text Available The hand grip assistive device is a glove to assist old people who suffer from hand weakness in their daily life activities. The device earlier control system only use simple on and off switch. This required old people to use both hand to activate the device. The new control system of the hand grip assistive device was developed to allow single hand operation for old people. New control system take advantages of electromyography (EMG and flex sensor which was implemented to the device. It was programmed into active and semi-active mode operation. EMG sensors were placed on the forearm to capture EMG signal of Flexor Digitorum Profundus muscle to activate the device. Flex sensor was used to indicate the finger position and placed on top of the finger. The signal from both sensors then used to control the device. The new control system allowed single hand operation and designed to prevent user from over depended on the device by activating it through moving their fingers.

  10. 14 CFR 382.121 - What mobility aids and other assistive devices may passengers with a disability bring into the...

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false What mobility aids and other assistive... Aids, and Other Assistive Devices § 382.121 What mobility aids and other assistive devices may... or collapsible wheelchairs; (2) Other mobility aids, such as canes (including those used by persons...

  11. Association of HeartMate II left ventricular assist device flow estimate with thermodilution cardiac output.

    Science.gov (United States)

    Hasin, Tal; Huebner, Marianne; Li, Zhuo; Brown, Daniel; Stulak, John M; Boilson, Barry A; Joyce, Lyle; Pereira, Naveen L; Kushwaha, Sudhir S; Park, Soon J

    2014-01-01

    Cardiac output (CO) assessment is important in treating patients with heart failure. Durable left ventricular assist devices (LVADs) provide essentially all CO. In currently used LVADs, estimated device flow is generated by a computerized algorithm. However, LVAD flow estimate may be inaccurate in tracking true CO. We correlated LVAD (HeartMate II) flow with thermodilution CO during postoperative care (day 2-10 after implant) in 81 patients (5,616 paired measurements). Left ventricular assist device flow and CO correlated with a low correlation coefficient (r = 0.42). Left ventricular assist device readings were lower than CO measurements by approximately 0.36 L/min, trending for larger difference with higher values. Left ventricular assist device flow measurements showed less temporal variability compared with CO. Grouping for simultaneous measured blood pressure (BP device flow generally trends with measured CO, but large variability exists, hence flow measures should not be assumed to equal with CO. Clinicians should take into account variables such as high CO, BP, and opening of the aortic valve when interpreting LVAD flow readout. Direct flow sensors incorporated in the LVAD system may allow for better estimation.

  12. Assistive acting movement therapy devices with pneumatic rotary-type soft actuators.

    Science.gov (United States)

    Wilkening, André; Baiden, David; Ivlev, Oleg

    2012-12-01

    Inherent compliance and assistive behavior are assumed to be essential properties for safe human-robot interaction. Rehabilitation robots demand the highest standards in this respect because the machine interacts directly with weak persons who are often sensitive to pain. Using novel soft fluidic actuators with rotary elastic chambers (REC actuators), compact, lightweight, and cost-effective therapeutic devices can be developed. This article describes modular design and control strategies for new assistive acting robotic devices for upper and lower extremities. Due to the inherent compliance and natural back-drivability of pneumatic REC actuators, these movement therapy devices provide gentle treatment, whereby the interaction forces between humans and the therapy device are estimated without the use of expensive force/torque sensors. An active model-based gravity compensation based on separated models of the robot and of the individual patient's extremity provides the basis for effective assistive control. The utilization of pneumatic actuators demands a special safety concept, which is merged with control algorithms to provide a sufficient level of safeness and to catch any possible system errors and/or emergency situations. A self-explanatory user interface allows for easy, intuitive handling. Prototypes are very comfortable for use due to several control routines that work in the background. Assistive devices have been tested extensively with several healthy persons; the knee/hip movement therapy device is now under clinical trials at the Clinic for Orthopaedics and Trauma Surgery at the Klinikum Stuttgart.

  13. A Passively-Suspended Tesla Pump Left Ventricular Assist Device

    Science.gov (United States)

    Izraelev, Valentin; Weiss, William J.; Fritz, Bryan; Newswanger, Raymond K.; Paterson, Eric G.; Snyder, Alan; Medvitz, Richard B.; Cysyk, Joshua; Pae, Walter E.; Hicks, Dennis; Lukic, Branka; Rosenberg, Gerson

    2009-01-01

    The design and initial test results of a new passively suspended Tesla type LAVD blood pump are described. CFD analysis was used in the design of the pump. Overall size of the prototype device is 50 mm in diameter and 75 mm in length. The pump rotor has a density lower than that of blood and when spinning inside the stator in blood it creates a buoyant centering force that suspends the rotor in the radial direction. The axial magnetic force between the rotor and stator restrain the rotor in the axial direction. The pump is capable of pumping up to 10 liters/min at a 70 mmHg head rise at 8000 RPM. The pump has demonstrated a normalized index of hemolysis level below .02 mg/dL for flows between 2 and 9.7 L/min. An inlet pressure sensor has also been incorporated into the inlet cannula wall and will be used for control purposes. One initial in vivo study showed an encouraging result. Further CFD modeling refinements are planned as well as endurance testing of the device. PMID:19770799

  14. Laser assisted soldering: microdroplet accumulation with a microjet device.

    Science.gov (United States)

    Chan, E K; Lu, Q; Bell, B; Motamedi, M; Frederickson, C; Brown, D T; Kovach, I S; Welch, A J

    1998-01-01

    We investigated the feasibility of a microjet to dispense protein solder for laser assisted soldering. Successive micro solder droplets were deposited on rat dermis and bovine intima specimens. Fixed laser exposure was synchronized with the jetting of each droplet. After photocoagulation, each specimen was cut into two halves at the center of solder coagulum. One half was fixed immediately, while the other half was soaked in phosphate-buffered saline for a designated hydration period before fixation (1 hour, 1, 2, and 7 days). After each hydration period, all tissue specimens were prepared for scanning electron microscopy (SEM). Stable solder coagulum was created by successive photocoagulation of microdroplets even after the soldered tissue exposed to 1 week of hydration. This preliminary study suggested that tissue soldering with successive microdroplets is feasible even with fixed laser parameters without active feedback control.

  15. Sensor-Based Assistive Devices for Visually-Impaired People: Current Status, Challenges, and Future Directions

    Directory of Open Access Journals (Sweden)

    Wafa Elmannai

    2017-03-01

    Full Text Available The World Health Organization (WHO reported that there are 285 million visuallyimpaired people worldwide. Among these individuals, there are 39 million who are totally blind. There have been several systems designed to support visually-impaired people and to improve the quality of their lives. Unfortunately, most of these systems are limited in their capabilities. In this paper, we present a comparative survey of the wearable and portable assistive devices for visuallyimpaired people in order to show the progress in assistive technology for this group of people. Thus, the contribution of this literature survey is to discuss in detail the most significant devices that are presented in the literature to assist this population and highlight the improvements, advantages, disadvantages, and accuracy. Our aim is to address and present most of the issues of these systems to pave the way for other researchers to design devices that ensure safety and independent mobility to visually-impaired people.

  16. Sensor-Based Assistive Devices for Visually-Impaired People: Current Status, Challenges, and Future Directions

    Science.gov (United States)

    Elmannai, Wafa; Elleithy, Khaled

    2017-01-01

    The World Health Organization (WHO) reported that there are 285 million visually-impaired people worldwide. Among these individuals, there are 39 million who are totally blind. There have been several systems designed to support visually-impaired people and to improve the quality of their lives. Unfortunately, most of these systems are limited in their capabilities. In this paper, we present a comparative survey of the wearable and portable assistive devices for visually-impaired people in order to show the progress in assistive technology for this group of people. Thus, the contribution of this literature survey is to discuss in detail the most significant devices that are presented in the literature to assist this population and highlight the improvements, advantages, disadvantages, and accuracy. Our aim is to address and present most of the issues of these systems to pave the way for other researchers to design devices that ensure safety and independent mobility to visually-impaired people. PMID:28287451

  17. Improving hemodynamics of cardiovascular system under a novel intraventricular assist device support via modeling and simulations.

    Science.gov (United States)

    Zhu, Shidong; Luo, Lin; Yang, Bibo; Li, Xinghui; Wang, Xiaohao

    2017-12-01

    Ventricular assist devices (LVADs) are increasingly recognized for supporting blood circulation in heart failure patients who are non-transplant eligible. Because of its volume, the traditional pulsatile device is not easy to implant intracorporeally. Continuous flow LVADs (CF-LVADs) reduce arterial pulsatility and only offer continuous flow, which is different from physiological flow, and may cause long-term complications in the cardiovascular system. The aim of this study was to design a new pulsatile assist device that overcomes this disadvantage, and to test this device in the cardiovascular system. Firstly, the input and output characteristics of the new device were tested in a simple cardiovascular mock system. A detailed mathematical model was established by fitting the experimental data. Secondly, the model was tested in four pathological cases, and was simulated and coupled with a fifth-order cardiovascular system and a new device model using Matlab software. Using assistance of the new device, we demonstrated that the left ventricle pressure, aortic pressure, and aortic flow of heart failure patients improved to the levels of a healthy individual. Especially, in state IV level heart failure patients, the systolic blood pressure increased from 81.34 mmHg to 132.1 mmHg, whereas the diastolic blood pressure increased from 54.28 mmHg to 78.7 mmHg. Cardiac output increased from 3.21 L/min to 5.16 L/min. The newly-developed assist device not only provided a physiological flow that was similar to healthy individuals, but also effectively improved the ability of the pathological ventricular volume. Finally, the effects of the new device on other hemodynamic parameters are discussed.

  18. Embedded Control System for Smart Walking Assistance Device.

    Science.gov (United States)

    Bosnak, Matevz; Skrjanc, Igor

    2017-03-01

    This paper presents the design and implementation of a unique control system for a smart hoist, a therapeutic device that is used in rehabilitation of walking. The control system features a unique human-machine interface that allows the human to intuitively control the system just by moving or rotating its body. The paper contains an overview of the complete system, including the design and implementation of custom sensors, dc servo motor controllers, communication interfaces and embedded-system based central control system. The prototype of the complete system was tested by conducting a 6-runs experiment on 11 subjects and results are showing that the proposed control system interface is indeed intuitive and simple to adopt by the user.

  19. The embodiment of assistive devices-from wheelchair to exoskeleton

    Science.gov (United States)

    Pazzaglia, Mariella; Molinari, Marco

    2016-03-01

    Spinal cord injuries (SCIs) place a heavy burden on the healthcare system and have a high personal impact and marked socio-economic consequences. Clinically, no absolute cure for these conditions exists. However, in recent years, there has been an increased focus on new robotic technologies that can change the frame we think about the prognosis for recovery and for treating some functions of the body affected after SCIs. This review has two goals. The first is to assess the possibility of the embodiment of functional assistive tools after traumatic disruption of the neural pathways between the brain and the body. To this end, we will examine how altered sensorimotor information modulates the sense of the body in SCI. The second goal is to map the phenomenological experience of using external tools that typically extend the potential of the body physically impaired by SCI. More specifically, we will focus on the difference between the perception of one's physically augmented and non-augmented affected body based on observable and measurable behaviors. We discuss potential clinical benefits of enhanced embodiment of the external objects by way of multisensory interventions. This review argues that the future evolution of human robotic technologies will require adopting an embodied approach, taking advantage of brain plasticity to allow bionic limbs to be mapped within the neural circuits of physically impaired individuals.

  20. The embodiment of assistive devices-from wheelchair to exoskeleton.

    Science.gov (United States)

    Pazzaglia, Mariella; Molinari, Marco

    2016-03-01

    Spinal cord injuries (SCIs) place a heavy burden on the healthcare system and have a high personal impact and marked socio-economic consequences. Clinically, no absolute cure for these conditions exists. However, in recent years, there has been an increased focus on new robotic technologies that can change the frame we think about the prognosis for recovery and for treating some functions of the body affected after SCIs. This review has two goals. The first is to assess the possibility of the embodiment of functional assistive tools after traumatic disruption of the neural pathways between the brain and the body. To this end, we will examine how altered sensorimotor information modulates the sense of the body in SCI. The second goal is to map the phenomenological experience of using external tools that typically extend the potential of the body physically impaired by SCI. More specifically, we will focus on the difference between the perception of one's physically augmented and non-augmented affected body based on observable and measurable behaviors. We discuss potential clinical benefits of enhanced embodiment of the external objects by way of multisensory interventions. This review argues that the future evolution of human robotic technologies will require adopting an embodied approach, taking advantage of brain plasticity to allow bionic limbs to be mapped within the neural circuits of physically impaired individuals. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Ventricular assist device implantation in a young patient with non-compaction cardiomyopathy and hereditary spherocytosis.

    Science.gov (United States)

    Huenges, Katharina; Panholzer, Bernd; Cremer, Jochen; Haneya, Assad

    2018-04-01

    A case of a 15-year-old female patient with acute heart failure due to non-compaction cardiomyopathy and hereditary anaemia (hereditary spherocytic elliptocytosis) requiring ventricular assist device implantation as a bridge to transplantation is presented. The possible effects of mechanical stress on erythrocytes potentially induced by mechanical circulatory support remains unclear, but it may lead to haemolytic crisis in patients suffering from hereditary anaemia. In our case, ventricular assist device therapy was feasible, and haematological complications did not occur within 6 weeks of bridging our patient to heart transplantation.

  2. Intelligent speed adaptation as an assistive device for drivers with acquired brain injury

    DEFF Research Database (Denmark)

    Klarborg, Brith; Lahrmann, Harry Spaabæk; Agerholm, Niels

    2012-01-01

    Intelligent speed adaptation (ISA) was tested as an assistive device for drivers with an acquired brain injury (ABI). The study was part of the “Pay as You Speed” project (PAYS) and used the same equipment and technology as the main study (Lahrmann et al., in press-a, in press-b). Two drivers......, and in general they described driving with ISA as relaxed. ISA reduced the percentage of the total distance that was driven with a speed above the speed limit (PDA), but the subjects relapsed to their previous PDA level in Baseline 2. This suggests that ISA is more suited as a permanent assistive device (i...

  3. Non-Exposure, Device-Assisted Endoscopic Full-thickness Resection.

    Science.gov (United States)

    Bauder, Markus; Schmidt, Arthur; Caca, Karel

    2016-04-01

    Recent developments have expanded the frontier of interventional endoscopy toward more extended resections following surgical principles. This article presents two new device-assisted techniques for endoscopic full-thickness resection in the upper and lower gastrointestinal tract. Both methods are nonexposure techniques avoiding exposure of gastrointestinal contents to the peritoneal cavity by a "close first-cut later" principle. The full-thickness resection device is a novel over-the-scope device designed for clip-assisted full-thickness resection of colorectal lesions. Endoscopic full-thickness resection of gastric subepithelial tumors can be performed after placing transmural sutures underneath the tumor with a suturing device originally designed for endoscopic antireflux therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Pre-ejection period by radial artery tonometry supplements echo doppler findings during biventricular pacemaker optimization

    Directory of Open Access Journals (Sweden)

    Qamruddin Salima

    2011-07-01

    Full Text Available Abstract Background Biventricular (Biv pacemaker echo optimization has been shown to improve cardiac output however is not routinely used due to its complexity. We investigated the role of a simple method involving computerized pre-ejection time (PEP assessment by radial artery tonometry in guiding Biv pacemaker optimization. Methods Blinded echo and radial artery tonometry were performed simultaneously in 37 patients, age 69.1 ± 12.8 years, left ventricular (LV ejection fraction (EF 33 ± 10%, during Biv pacemaker optimization. Effect of optimization on echo derived velocity time integral (VTI, ejection time (ET, myocardial performance index (MPI, radial artery tonometry derived PEP and echo-radial artery tonometry derived PEP/VTI and PEP/ET indices was evaluated. Results Significant improvement post optimization was achieved in LV ET (286.9 ± 37.3 to 299 ± 34.6 ms, p Conclusion An acute shortening of PEP by radial artery tonometry occurs post Biv pacemaker optimization and correlates with improvement in hemodynamics by echo Doppler and may provide a cost-efficient approach to assist with Biv pacemaker echo optimization.

  5. Inappropriate shock and battery switching to "End of Life" in a patient with biventricular ICD during magnetic resonance imaging.

    Science.gov (United States)

    Atar, İlyas; Bal, Uğur; Ertan, Çağatay; Özin, Bülent; Müderrisoğlu, Haldun

    2016-01-01

    Presence of a cardiac pacemaker or implantable cardioverter defibrillator (ICD) is a relative contraindication to magnetic resonance imaging (MRI). Biventricular ICDs are often used in the treatment of advanced heart failure; however, reports on experience with biventricular ICDs are lacking in the literature. In this case report, we describe a pacemaker-dependent patient with a biventricular ICD on whom an MRI of the lumbar spine was performed without having realized the presence of the ICD.

  6. Using left-ventricular-only pacing to eliminate T-wave oversensing in a biventricular implantable cardiac defibrillator.

    Science.gov (United States)

    Khoo, Clarence; Bennett, Matthew; Chakrabarti, Santabhanu; LeMaitre, John; Tung, Stanley K K

    2013-02-01

    A man aged 75 years and with nonischemic cardiomyopathy had implantation of a biventricular implantable cardiac defibrillator (ICD). Consistent biventricular pacing was limited by intermittent T-wave oversensing (TWOS). A strategy of left-ventricular-only pacing was used to eliminate TWOS. This strategy obviates the need to reduce ventricular sensitivity and thus may be an effective alternative to biventricular pacing complicated by TWOS. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  7. Left ventricular assist device management in patients chronically supported for advanced heart failure.

    Science.gov (United States)

    Cowger, Jennifer; Romano, Matthew A; Stulak, John; Pagani, Francis D; Aaronson, Keith D

    2011-03-01

    This review summarizes management strategies to reduce morbidity and mortality in heart failure patients supported chronically with implantable left ventricular assist devices (LVADs). As the population of patients supported with long-term LVADs has grown, patient selection, operative technique, and patient management strategies have been refined, leading to improved outcomes. This review summarizes recent findings on LVAD candidate selection, and discusses outpatient strategies to optimize device performance and heart failure management. It also reviews important device complications that warrant close outpatient monitoring. Managing patients on chronic LVAD support requires regular patient follow-up, multidisciplinary care teams, and frequent laboratory and echocardiographic surveillance to ensure optimal outcomes.

  8. Left Ventricular Assist Device Implantation with Concomitant Aortic Valve and Ascending Aortic Replacement.

    Science.gov (United States)

    Huenges, Katharina; Panholzer, Bernd; Cremer, Jochen; Haneya, Assad

    2018-01-01

    Left ventricular assist device (LVAD) is nowadays a routine therapy for patients with advanced heart failure. We present the case of a 74-year-old male patient who was admitted to our center with terminal heart failure in dilated cardiomyopathy and ascending aortic aneurysm with aortic valve regurgitation. The LVAD implantation with simultaneous aortic valve and supracoronary ascending aortic replacement was successfully performed.

  9. Extraction of the Electric Field in Field Plate Assisted RESURF Devices

    NARCIS (Netherlands)

    Boksteen, B.K.; Dhar, S.; Heringa, A.; Koops, G.E.J.; Hueting, Raymond Josephus Engelbart

    2012-01-01

    It has previously been reported that the lateral electric field (Ex) in the drain extension of thin SOI HV (700V) field plate assisted RESURF devices can be extracted from their ID-VD characteristics in the subthreshold regime. In this work the prerequisites for valid field extraction and the

  10. Psychological distress in patients with a left ventricular assist device and their partners : An exploratory study

    NARCIS (Netherlands)

    Brouwers, C.J.; Denollet, J.; Caliskan, K.; de Jonge, N.; Constantinescu, A.; Young, Q.; Kaan, A.; Pedersen, S.S.

    2015-01-01

    Background: Left ventricular assist device (LVAD) therapy is increasingly used in patients with advanced heart failure,and may have a significant psychological impact on both patients and their partners. Hence, we examined the distress levels of LVAD patients and their partners. Methods: Anxiety,

  11. Psychological distress in patients with a left ventricular assist device and their partners : an exploratory study

    NARCIS (Netherlands)

    Brouwers, Corline; Denollet, Johan; Caliskan, Kadir; de Jonge, N; Constantinescu, Alina; Young, Quincy; Kaan, Annemarie; Pedersen, Susanne S

    BACKGROUND: Left ventricular assist device (LVAD) therapy is increasingly used in patients with advanced heart failure, and may have a significant psychological impact on both patients and their partners. Hence, we examined the distress levels of LVAD patients and their partners. METHODS: Anxiety,

  12. Minimally Invasive Cochlear Implantation Assisted by Bi-planar Device: An Exploratory Feasibility Study in vitro

    Directory of Open Access Journals (Sweden)

    Jia Ke

    2016-01-01

    Conclusions: This exploratory study demonstrated the safety of the newly developed image-guided minimally invasive cochlear implantation assisted by the bi-planar device and established the operational procedures. Further, more in vitro experiments are needed to improve the system operation and its safety.

  13. Assistive device use and mobility-related factors among adults aged≥65years.

    Science.gov (United States)

    West, Bethany A; Bhat, Geeta; Stevens, Judy; Bergen, Gwen

    2015-12-01

    Examining how assistive device (cane, walker) use relates to other mobility factors can provide insight into older adults' future mobility needs. Data come from the Second Injury Control and Risk Survey, Phase 2 (ICARIS2-P2), conducted from March 2007 to May 2008. Prevalence estimates were calculated for older adults (aged ≥65) and multivariable logistic regression was used to explore associations between assistive device use and mobility-related characteristics. Compared with non-users, assistive device users were more likely to report a recent fall (AOR 12.0; 95% CI 4.9-29.3), limit walking outside due to concerns about falling (AOR 7.1; 95% CI 2.6-19.1), be unable to walk outside for 10min without resting (AOR 3.3; 95% CI 1.1-9.3), and be no longer driving (AOR 6.7; 95% CI 2.0-22.3). Assistive device users have limited mobility and an increased risk for fall injury compared with non-users. Effective fall prevention interventions, and innovative transportation options, are needed to protect the mobility of this high-risk group. Published by Elsevier Ltd.

  14. Right ventricular failure after implantation of a continuous-flow left ventricular assist device

    DEFF Research Database (Denmark)

    Cordtz, Johan Joakim; Nilsson, Jens C; Hansen, Peter B

    2014-01-01

    Right ventricular failure (RVF) is a significant complication after implantation of a left ventricular assist device. We aimed to identify haemodynamic changes in the early postoperative phase that predicted subsequent development of RVF in a cohort of HeartMate II (HMII) implanted patients....

  15. Left ventricular assist device implantation via left thoracotomy: alternative to repeat sternotomy.

    Science.gov (United States)

    Pierson, Richard N; Howser, Renee; Donaldson, Terri; Merrill, Walter H; Dignan, Rebecca J; Drinkwater, Davis C; Christian, Karla G; Butler, Javed; Chomsky, Don; Wilson, John R; Clark, Rick; Davis, Stacy F

    2002-03-01

    Repeat sternotomy for left ventricular assist device insertion may result in injury to the right heart or patent coronary grafts, complicating intraoperative and postoperative management. In 4 critically ill patients, left thoracotomy was used as an alternative to repeat sternotomy. Anastomosis of the outflow conduit to the descending thoracic aorta provided satisfactory hemodynamic support.

  16. COST-EFFECTIVENESS OF CONTINUOUS-FLOW LEFT VENTRICULAR ASSIST DEVICES

    NARCIS (Netherlands)

    Neyt, Mattias; Van den Bruel, Ann; Smit, Yolba; De Jonge, Nicolaas; Erasmus, Michiel; Van Dijk, Diederik; Vlayen, Joan

    Objectives: Mechanical circulatory support through left ventricular assist devices (LVADs) improves survival and quality of life for patients with end-stage heart failure who are ineligible for cardiac transplantation. Our aim was to calculate the cost-effectiveness of continuous-flow LVADs.

  17. A Systematic Review on Existing Measures for the Subjective Assessment of Rehabilitation and Assistive Robot Devices

    Directory of Open Access Journals (Sweden)

    Yiannis Koumpouros

    2016-01-01

    Full Text Available The objective of the current study is to identify and classify outcome measures currently used for the assessment of rehabilitation or assistive robot devices. We conducted a systematic review of the literature using PubMed, MEDLINE, CIRRIE, and Scopus databases for studies that assessed rehabilitation or assistive robot devices from 1980 through January 2016. In all, 31 articles met all inclusion criteria. Tailor-made questionnaires were the most commonly used tool at 66.7%, while the great majority (93.9% of the studies used nonvalidated instruments. The study reveals the absence of a standard scale which makes it difficult to compare the results from different researchers. There is a great need, therefore, for a valid and reliable instrument to be available for use by the intended end users for the subjective assessment of robot devices. The study concludes by identifying two scales that have been validated in general assistive technology devices and could support the scope of subjective assessment in rehabilitation or assistive robots (however, with limited coverage and a new one called PYTHEIA, recently published. The latter intends to close the gap and help researchers and developers to evaluate, assess, and produce products that satisfy the real needs of the end users.

  18. Noninvasive arterial blood pressure waveforms in patients with continuous-flow left ventricular assist devices

    NARCIS (Netherlands)

    Martina, Jerson R.; Westerhof, Berend E.; de Jonge, Nicolaas; van Goudoever, Jeroen; Westers, Paul; Chamuleau, Steven; van Dijk, Diederik; Rodermans, Ben F. M.; de Mol, Bas A. J. M.; Lahpor, Jaap R.

    2014-01-01

    Arterial blood pressure and echocardiography may provide useful physiological information regarding cardiac support in patients with continuous-flow left ventricular assist devices (cf-LVADs). We investigated the accuracy and characteristics of noninvasive blood pressure during cf-LVAD support.

  19. New Monitoring Technology to Objectively Assess Adherence to Prescribed Footwear and Assistive Devices During Ambulatory Activity

    NARCIS (Netherlands)

    Bus, Sicco A.; Waaijman, Roelof; Nollet, Frans

    2012-01-01

    Bus SA, Waaijman R, Nollet F. New monitoring technology to objectively assess adherence to prescribed footwear and assistive devices during ambulatory activity. Arch Phys Med Rehabil 2012;93:2075-9. Objective: To assess the validity and feasibility of a new temperature-based adherence monitor to

  20. Surface Modifications of Polymeric Materials for Application in Artificial Heart and Circulatory Assist Devices

    NARCIS (Netherlands)

    Feijen, J.; Engbers, G.H.M.; Terlingen, J.G.A.; van Delden, C.J.; Poot, A.A.; Vaudaux, P.; Akutsu, Tetsuzo; Koyanagi, Hitoshi

    1996-01-01

    Several methods have been developed to modify the surfaces of materials used in artificial hearts and circulatory assist devices to suppress the host response, especially with respect to the occurrence of clotting, cellular damage, and infections. In this review, special attention is paid to

  1. Embodying prostheses - how to let the body welcome assistive devices. Comment on "The embodiment of assistive devices-from wheelchair to exoskeleton" by M. Pazzaglia and M. Molinari

    Science.gov (United States)

    Longo, Matthew R.; Sadibolova, Renata; Tamè, Luigi

    2016-03-01

    A growing body of research has focused on the development of assistive devises to improve the recovery and ameliorate the quality of life of people suffering from spinal cord injuries (SCI). In their stimulating and timely paper, Pazzaglia and Molinari [1] review the significant progress made by biotechnology studies in providing increasing sophisticated assistive tools (e.g., prostheses and exoskeletons) that extend the functionality of patients' bodies. However, despite this extraordinary technological effort [2], it remains uncertain how these devices can be appropriately embedded into the mental representation of the body. Here, we wish to amplify the points raised by Pazzaglia and Molinari by discussing three challenges facing work on embodying prostheses raised by experimental research on body representation.

  2. The influence of device position on the flow within the Penn State 12 cc pediatric ventricular assist device.

    Science.gov (United States)

    Schönberger, Markus; Deutsch, Steven; Manning, Keefe B

    2012-01-01

    Ventricular assist devices are a commonly used heart failure therapy for adult patients as bridge-to-transplant or bridge-to-recovery tools. The application of adult ventricular assist devices in pediatric patients has led to increased thrombotic events. Therefore, we have been developing a pediatric ventricular assist device (PVAD), the Penn State 12 cc PVAD. It is designed for patients with a body weight of 5-15 kg and has a stroke volume of 12 cc. Clot formation is the major concern. It is correlated to the coagulability of blood, the blood contacting materials and the fluid dynamics within the system. The intent is for the PVAD to be a long term therapy. Therefore, the system may be oriented in different positions according to the patient's behavior. This study evaluates for the first time the impact of position on the flow patterns within the Penn State 12 cc PVAD, which may help to improve the PVAD design concerning chamber and ports geometries. The fluid dynamics are visualized by particle image velocimetry. The evaluation is based on inlet jet behavior and calculated wall shear rates. Vertical and horizontal model orientations are compared, both with a beat rate of 75, outlet pressures of 90/60 mm Hg and a flow rate of 1.3 l/min. The results show a significant change of the inlet jet behavior and the development of a rotational flow pattern. Vertically, the inlet jet is strong along the wall. It initiates a rotational flow pattern with a wandering axis of rotation. In contrast, the horizontal model orientation results show a weaker inlet jet along the wall with a nearly constant center of rotation location, which can be correlated to a higher risk of thrombotic events. In addition, high speed videography illustrates differences in the diaphragm motion during diastole. Diaphragm opening trajectories measurements determine no significant impact of the density of the blood analog fluids. Hence, the results correlate to human blood.

  3. 49 CFR 39.93 - What wheelchairs and other assistive devices may passengers with a disability bring onto a...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false What wheelchairs and other assistive devices may passengers with a disability bring onto a passenger vessel? 39.93 Section 39.93 Transportation Office of the... and Services to Passengers With Disabilities § 39.93 What wheelchairs and other assistive devices may...

  4. [Intelligent operating room suite : From passive medical devices to the self-thinking cognitive surgical assistant].

    Science.gov (United States)

    Kenngott, H G; Wagner, M; Preukschas, A A; Müller-Stich, B P

    2016-12-01

    Modern operating room (OR) suites are mostly digitally connected but until now the primary focus was on the presentation, transfer and distribution of images. Device information and processes within the operating theaters are barely considered. Cognitive assistance systems have triggered a fundamental rethinking in the automotive industry as well as in logistics. In principle, tasks in the OR, some of which are highly repetitive, also have great potential to be supported by automated cognitive assistance via a self-thinking system. This includes the coordination of the entire workflow in the perioperative process in both the operating theater and the whole hospital. With corresponding data from hospital information systems, medical devices and appropriate models of the surgical process, intelligent systems could optimize the workflow in the operating theater in the near future and support the surgeon. Preliminary results on the use of device information and automatically controlled OR suites are already available. Such systems include, for example the guidance of laparoscopic camera systems. Nevertheless, cognitive assistance systems that make use of knowledge about patients, processes and other pieces of information to improve surgical treatment are not yet available in the clinical routine but are urgently needed in order to automatically assist the surgeon in situation-related activities and thus substantially improve patient care.

  5. Impact of pacing modality and biventricular pacing on cardiac output and coronary conduit flow in the post-cardiotomy patient.

    LENUS (Irish Health Repository)

    Healy, David G

    2012-02-03

    We have previously demonstrated the role of univentricular pacing modalities in influencing coronary conduit flow in the immediate post-operative period in the cardiac surgery patient. We wanted to determine the mechanism of this improved coronary conduit and, in addition, to explore the possible benefits with biventricular pacing. Sixteen patients undergoing first time elective coronary artery bypass grafting who required pacing following surgery were recruited. Comparison of cardiac output and coronary conduit flow was performed between VVI and DDD pacing with a single right ventricular lead and biventricular pacing lead placement. Cardiac output was measured using arterial pulse waveform analysis while conduit flow was measured using ultrasonic transit time methodology. Cardiac output was greatest with DDD pacing using right ventricular lead placement only [DDD-univentricular 5.42 l (0.7), DDD-biventricular 5.33 l (0.8), VVI-univentricular 4.71 l (0.8), VVI-biventricular 4.68 l (0.6)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.023) and VVI-biventricular pacing (P=0.001) but there was no significant advantage to DDD-biventricular pacing (P=0.45). In relation to coronary conduit flow, DDD pacing again had the highest flow [DDD-univentricular 55 ml\\/min (24), DDD-biventricular 52 ml\\/min (25), VVI-univentricular 47 ml\\/min (23), VVI-biventricular 50 ml\\/min (26)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.006) pacing but not significantly different to VVI-biventricular pacing (P=0.109) or DDD-biventricular pacing (P=0.171). Pacing with a DDD modality offers the optimal coronary conduit flow by maximising cardiac output. Biventricular lead placement offered no significant benefit to coronary conduit flow or cardiac output.

  6. A novel vibration assisted polishing device based on the flexural mechanism driven by the piezoelectric actuators

    Directory of Open Access Journals (Sweden)

    Guilian Wang

    2018-01-01

    Full Text Available The vibration assisted polishing has widely application fields because of higher machining frequency and better polishing quality, especially the polishing with the non-resonant mode that is regarded as a kind of promising polishing method. This paper reports a novel vibration assisted polishing device, consisting of the flexible hinge mechanism driven by the piezoelectric actuators, which is suitable for polishing planes or curve surfaces with slow curvature. Firstly, the generation methods of vibration trajectory are investigated for the same frequency and different frequency signals’ inputs, respectively, and then the types of elliptic and Lissajous’s vibration trajectories are generated respectively. Secondly, a flexural mechanism consisting of the right circular flexible hinges and the leaf springs is developed to produce two-dimensional vibration trajectory. Statics and dynamics investigating of this flexible mechanism are finished in detail. The analytical models about input and output compliances of the flexural mechanism are established according to the matrix-based compliance modeling, and the dynamic model of the flexural mechanism based on the Euler-Lagrange equation is also presented. The finite element model of the flexural mechanism was established to carry out the numerical simulation in order to testify the rationality of device design. Finally, the polishing experiment is carried out to prove the effectiveness of the vibration device. The experimental results show that this novel vibration assisted polishing device developed in this study can remove more effectively the cutting marks left by last process and obviously reduce the workpiece surface roughness.

  7. Management of severe ischemic cardiomyopathy: left ventricular assist device as destination therapy versus conventional bypass and mitral valve surgery.

    Science.gov (United States)

    Maltais, Simon; Tchantchaleishvili, Vahtang; Schaff, Hartzell V; Daly, Richard C; Suri, Rakesh M; Dearani, Joseph A; Topilsky, Yan; Stulak, John M; Joyce, Lyle D; Park, Soon J

    2014-04-01

    Patients with severe ischemic cardiomyopathy (left ventricular ejection fraction assist device as destination therapy is reserved for patients who are too high risk for conventional surgery. We evaluated our outcomes with conventional surgery within this population and the comparative effectiveness of these 2 therapies. We identified patients who underwent conventional surgery or left ventricular assist device as destination therapy for severe ischemic cardiomyopathy (left ventricular ejection fraction assist device as destination therapy. We compared baseline patient characteristics and outcomes in terms of end-organ function and survival. A total of 88 patients were identified; 55 patients underwent conventional surgery (63%), and 33 patients (37%) received a left ventricular assist device as destination therapy. Patients who received left ventricular assist device as destination therapy had the increased prevalence of renal failure, inotrope dependency, and intra-aortic balloon support. Patients undergoing conventional surgery required longer ventilatory support, and patients receiving a left ventricular assist device required more reoperation for bleeding. Mortality rates were similar between the 2 groups at 30 days (7% in the conventional surgery group vs 3% in the left ventricular assist device as destination therapy group, P = .65) and at 1 year (22% in the conventional surgery group vs 15% in the left ventricular assist device as destination therapy group, P = .58). There was a trend toward improved survival in patients receiving a left ventricular assist device compared with the propensity-matched groups at 1 year (94% vs 71%, P = .171). The operative mortality and early survival after conventional surgery seem to be acceptable. For inoperable or prohibitive-risk patients, left ventricular assist device as destination therapy can be offered with similar outcomes. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby

  8. Interacting with and via mobile devices and mobile robots in an assisted living setting

    Directory of Open Access Journals (Sweden)

    Maria Dagioglou

    2015-05-01

    Full Text Available Using robotic home assistants as a platform for remote health monitoring offers several advantages, but also presents considerable challenges related to both the technical immaturity of home robotics and to user acceptance issues. In this paper we explore tablets and similar mobile devices as the medium of communication between robots and their users, presenting relevant current and planned research in humanrobot interaction that can help the telehealth community circumvent technical shortcomings, improve user acceptance, and maximize the quality of the data collected by robotic home assistants.

  9. Biventricular / Left Ventricular Pacing in Hypertrophic Obstructive Cardiomyopathy: An Overview

    Directory of Open Access Journals (Sweden)

    Radu Vatasescu, MD

    2012-05-01

    Full Text Available Hypertrophic cardiomyopathy (HCM is an autosomal dominant inherited genetic disease characterized by compensatory pathological left ventricle (LV hypertrophy due to sarcomere dysfunction. In an important proportion of patients with HCM, the site and extent of cardiac hypertrophy results in severe obstruction to LV outflow tract (LVOT, contributing to disabling symptoms and increasing the risk of sudden cardiac death (SCD. In patients with progressive and/or refractory symptoms despite optimal pharmacological treatment, invasive therapies that diminish or abolish LVOT obstruction relieve heart failure-related symptoms, improve quality of life and could be associated with long-term survival similar to that observed in the general population. The gold standard in this respect is surgical septal myectomy, which might be supplementary associated with a reduction in SCD. Percutaneous techniques, particularly alcohol septal ablation (ASA and more recently radiofrequency (RF septal ablation, can achieve LVOT gradient reduction and symptomatic benefit in a large proportion of HOCM patients at the cost of a supposedly limited septal myocardial necrosis and a 10-20% risk of chronic atrioventricular block. After an initial period of enthusiasm, standard DDD pacing failed to show in randomized trials significant LVOT gradient reductions and objective improvement in exercise capacity. However, case reports and recent small pilot studies suggested that atrial synchronous LV or biventricular (biV pacing significantly reduce LVOT obstruction and improve symptoms (acutely as well as long-term in a large proportion of severely symptomatic HOCM patients not suitable to other gradient reduction therapies. Moreover, biV/LV pacing in HOCM seems to be associated with significant LV reverse remodelling.

  10. The impact of mobility assistive technology devices on participation for individuals with disabilities.

    Science.gov (United States)

    Carver, Jordan; Ganus, Ashley; Ivey, Jon Mark; Plummer, Teresa; Eubank, Ann

    2016-08-01

    This study aims to address the gap in research and contribute to the body of knowledge on the perspectives assistive technology device users have toward their devices. Mixed methods were used to better understand the impact of mobility assistive technology devices (MATDs) on participation for individuals with disabilities. The Functional Mobility Assessment was administered in conjunction with two qualitative questions developed by the research team allowing participants to expound on the impact of their MATD experience. Participants were recruited online via the National Spinal Cord Injury Association website and in-person at Abilities Expo in Atlanta, Georgia, and the International Seating Symposium in Nashville, Tennessee. Results are consistent with findings from prior research regarding accessibility for individuals with disabilities. Corresponding findings were found in both the quantitative and qualitative data and are categorized into several major themes: environment (indoor and outdoor), surface heights, transportation, dependence, independence, quality of life and participation. Quantitative data from this study indicate that users of MATD are satisfied with the way in which their devices enable maneuvering indoors, while qualitative data suggest otherwise. Implications for healthcare practitioners are described and future recommendations are provided. Implications for Rehabilitation Healthcare professionals should advocate for proper mobility assistive technology devices (MATDs) for their patients in order to enable increased independence, safety and efficiency. Healthcare professionals must be cognizant of the impact of the environment and/or environmental barriers when prescribing MATD. Additional areas of interest for future research may include investigating the impact of MATD in association with date of onset of disability, according to diagnoses, or specific to length of time since acquiring the device.

  11. Developing an Anti-Xa-Based Anticoagulation Protocol for Patients with Percutaneous Ventricular Assist Devices.

    Science.gov (United States)

    Sieg, Adam; Mardis, B Andrew; Mardis, Caitlin R; Huber, Michelle R; New, James P; Meadows, Holly B; Cook, Jennifer L; Toole, J Matthew; Uber, Walter E

    2015-01-01

    Because of the complexities associated with anticoagulation in temporary percutaneous ventricular assist device (pVAD) recipients, a lack of standardization exists in their management. This retrospective analysis evaluates current anticoagulation practices at a single center with the aim of identifying an optimal anticoagulation strategy and protocol. Patients were divided into two cohorts based on pVAD implanted (CentriMag (Thoratec; Pleasanton, CA) / TandemHeart (CardiacAssist; Pittsburgh, PA) or Impella (Abiomed, Danvers, MA)), with each group individually analyzed for bleeding and thrombotic complications. Patients in the CentriMag/TandemHeart cohort were subdivided based on the anticoagulation monitoring strategy (activated partial thromboplastin time (aPTT) or antifactor Xa unfractionated heparin (anti-Xa) values). In the CentriMag/TandemHeart cohort, there were five patients with anticoagulation titrated based on anti-Xa values; one patient developed a device thrombosis and a major bleed, whereas another patient experienced major bleeding. Eight patients received an Impella pVAD. Seven total major bleeds in three patients and no thrombotic events were detected. Based on distinct differences between the devices, anti-Xa values, and outcomes, two protocols were created to guide anticoagulation adjustments. However, anticoagulation in patients who require pVAD support is complex with constantly evolving anticoagulation goals. The ideal level of anticoagulation should be individually determined using several coagulation laboratory parameters in concert with hemodynamic changes in the patient's clinical status, the device, and the device cannulation.

  12. Internal vacuum-assisted closure device in the swine model of severe liver injury

    Directory of Open Access Journals (Sweden)

    Everett Christopher B

    2012-12-01

    Full Text Available Abstract Objectives The authors present a novel approach to nonresectional therapy in major hepatic trauma utilizing intraabdominal perihepatic vacuum assisted closure (VAC therapy in the porcine model of Grade V liver injury. Methods A Grade V injury was created in the right lobe of the liver in a healthy pig. A Pringle maneuver was applied (4.5 minutes total clamp time and a vacuum assisted closure device was placed over the injured lobe and connected to suction. The device consisted of a perforated plastic bag placed over the liver, followed by a 15 cm by 15cm VAC sponge covered with a nonperforated plastic bag. The abdomen was closed temporarily. Blood loss, cardiopulmonary parameters and bladder pressures were measured over a one-hour period. The device was then removed and the animal was euthanized. Results Feasibility of device placement was demonstrated by maintenance of adequate vacuum suction pressures and seal. VAC placement presented no major technical challenges. Successful control of ongoing liver hemorrhage was achieved with the VAC. Total blood loss was 625 ml (20ml/kg. This corresponds to class II hemorrhagic shock in humans and compares favorably to previously reported estimated blood losses with similar grade liver injuries in the swine model. No post-injury cardiopulmonary compromise or elevated abdominal compartment pressures were encountered, while hepatic parenchymal perfusion was maintained. Conclusion These data demonstrate the feasibility and utility of a perihepatic negative pressure device for the treatment of hemorrhage from severe liver injury in the porcine model.

  13. TongueToSpeech (TTS): Wearable wireless assistive device for augmented speech.

    Science.gov (United States)

    Marjanovic, Nicholas; Piccinini, Giacomo; Kerr, Kevin; Esmailbeigi, Hananeh

    2017-07-01

    Speech is an important aspect of human communication; individuals with speech impairment are unable to communicate vocally in real time. Our team has developed the TongueToSpeech (TTS) device with the goal of augmenting speech communication for the vocally impaired. The proposed device is a wearable wireless assistive device that incorporates a capacitive touch keyboard interface embedded inside a discrete retainer. This device connects to a computer, tablet or a smartphone via Bluetooth connection. The developed TTS application converts text typed by the tongue into audible speech. Our studies have concluded that an 8-contact point configuration between the tongue and the TTS device would yield the best user precision and speed performance. On average using the TTS device inside the oral cavity takes 2.5 times longer than the pointer finger using a T9 (Text on 9 keys) keyboard configuration to type the same phrase. In conclusion, we have developed a discrete noninvasive wearable device that allows the vocally impaired individuals to communicate in real time.

  14. Creating Shape Templates for Patient Specific Biventricular Modeling in Congenital Heart Disease

    Science.gov (United States)

    Gilbert, Kathleen; Farrar, Genevieve; Cowan, Brett R.; Suinesiaputra, Avan; Occleshaw, Christopher; Pontré, Beau; Perry, James; Hegde, Sanjeet; Marsden, Alison; Omens, Jeff; McCulloch, Andrew; Young, Alistair A.

    2018-01-01

    Survival rates for infants with congenital heart disease (CHD) are improving, resulting in a growing population of adults with CHD. However, the analysis of left and right ventricular function is very time-consuming owing to the variety of congenital morphologies. Efficient customization of patient geometry and function depends on high quality shape templates specifically designed for the application. In this paper, we combine a method for creating finite element shape templates with an interactive template customization to patient MRI examinations. This enables different templates to be chosen depending on patient morphology. To demonstrate this pipeline, a new biventricular template with 162 elements was created and tested in place of an existing 82-element template. The method was able to provide fast interactive biventricular analysis with 0.31 sec per edit response time. The new template was customized to 13 CHD patients with similar biventricular topology, showing improved performance over the previous template and good agreement with clinical indices. PMID:26736353

  15. Design, analysis, and testing of a flexure-based vibration-assisted polishing device

    Science.gov (United States)

    Gu, Yan; Zhou, Yan; Lin, Jieqiong; Lu, Mingming; Zhang, Chenglong; Chen, Xiuyuan

    2018-05-01

    A vibration-assisted polishing device (VAPD) composed of leaf-spring and right-circular flexure hinges is proposed with the aim of realizing vibration-assisted machining along elliptical trajectories. To design the structure, energy methods and the finite-element method are used to calculate the performance of the proposed VAPD. An improved bacterial foraging optimization algorithm is used to optimize the structural parameters. In addition, the performance of the VAPD is tested experimentally. The experimental results indicate that the maximum strokes of the two directional mechanisms operating along the Z1 and Z2 directions are 29.5 μm and 29.3 μm, respectively, and the maximum motion resolutions are 10.05 nm and 10.01 nm, respectively. The maximum working bandwidth is 1,879 Hz, and the device has a good step response.

  16. Does reduced movement restrictions and use of assistive devices affect rehabilitation outcome after total hip replacement?

    DEFF Research Database (Denmark)

    Mikkelsen, Lone Ramer; Petersen, Annemette Krintel; Søballe, Kjeld

    2014-01-01

    slower recovery in patient-reported function after reduction in movement restrictions and use of assistive devices, but the difference was eliminated after 6 weeks. Reduced movement restrictions did not affect the other patient-reported outcomes and led to earlier return to work. CLINICAL REHABILITATION......). This group was compared to patients included the following 3 months with less restricted hip movement and use of assistive devices according to individual needs (unrestricted group). Questionnaires on function, pain, quality of life (HOOS), anxiety (HADS), working status and patient satisfaction were.......004). Return to work 6 weeks after THR for the unrestricted group compared to restricted group was: 53% versus 32% (P=0.045). No significant differences between groups in pain, symptoms, quality of life, anxiety/depression, hip dislocations and patient satisfaction. CONCLUSION: This study showed slightly...

  17. Implantation of a HeartMate II left ventricular assist device via left thoracotomy.

    Science.gov (United States)

    Cho, Yang Hyun; Deo, Salil V; Schirger, John A; Pereira, Naveen L; Stulak, John M; Park, Soon J

    2012-11-01

    Left thoracotomy was used as an approach for the implantation of pulsatile ventricular assist devices. Avoiding the standard approach of median sternotomy is attractive in patients undergoing complicated redo cardiac surgery, especially with prior mediastinal radiation. We report a case of the use of left thoracotomy for the implantation of the HeartMate II axial-flow pump. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Focused review on transthoracic echocardiographic assessment of patients with continuous axial left ventricular assist devices.

    Science.gov (United States)

    Topilsky, Yan; Maltais, Simon; Oh, Jae K; Atchison, Fawn W; Perrault, Louis P; Carrier, Michel; Park, Soon J

    2011-02-08

    Left ventricular assist devices (LVADs) are systems for mechanical support for patients with end-stage heart failure. Preoperative, postoperative and comprehensive followup with transthoracic echocardiography has a major role in LVAD patient management. In this paper, we will present briefly the hemodynamics of axial-flow LVAD, the rationale, and available data for a complete and organized echocardiographic assessment in these patients including preoperative assessment, postoperative and long-term evaluation.

  19. Evaluation of gait performance of knee osteoarthritis patients after total knee arthroplasty with different assistive devices

    OpenAIRE

    Tereso,Ana; Martins,Maria Manuel; Santos,Cristina Peixoto

    2015-01-01

    IntroductionNowadays Knee Osteoarthritis (KOA) affects a large percentage of the elderly, and one solution is to perform a Total Knee Arthroplasty (TKA). In this paper, one intends to study the gait and posture of these patients after the TKA, while walking with three assistive devices (ADs) (crutches, standard walker (SW) and rollator with forearm supports (RFS)).MethodsEleven patients were evaluated in 2 phases: 5 days and 15 days after surgery. This evaluation was conducted with two inerti...

  20. Assistive devices alter gait patterns in Parkinson disease: advantages of the four-wheeled walker.

    Science.gov (United States)

    Kegelmeyer, Deb A; Parthasarathy, Sowmya; Kostyk, Sandra K; White, Susan E; Kloos, Anne D

    2013-05-01

    Gait abnormalities are a hallmark of Parkinson's disease (PD) and contribute to fall risk. Therapy and exercise are often encouraged to increase mobility and decrease falls. As disease symptoms progress, assistive devices are often prescribed. There are no guidelines for choosing appropriate ambulatory devices. This unique study systematically examined the impact of a broad range of assistive devices on gait measures during walking in both a straight path and around obstacles in individuals with PD. Quantitative gait measures, including velocity, stride length, percent swing and double support time, and coefficients of variation were assessed in 27 individuals with PD with or without one of six different devices including canes, standard and wheeled walkers (two, four or U-Step). Data were collected using the GAITRite and on a figure-of-eight course. All devices, with the exception of four-wheeled and U-Step walkers significantly decreased gait velocity. The four-wheeled walker resulted in less variability in gait measures and had less impact on spontaneous unassisted gait patterns. The U-Step walker exhibited the highest variability across all parameters followed by the two-wheeled and standard walkers. Higher variability has been correlated with increased falls. Though subjects performed better on a figure-of-eight course using either the four-wheeled or the U-Step walker, the four-wheeled walker resulted in the most consistent improvement in overall gait variables. Laser light use on a U-Step walker did not improve gait measures or safety in figure-of-eight compared to other devices. Of the devices tested, the four-wheeled-walker offered the most consistent advantages for improving mobility and safety. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. A wound retraction device for laparoscopic-assisted intestinal surgery in dogs and cats.

    Science.gov (United States)

    Gower, Sara B; Mayhew, Philipp D

    2011-06-01

    To report experience with laparoscopic-assisted intestinal resection and anastomosis for treatment of discrete intestinal masses using a novel wound retraction device. Case series. Dogs (n=2) and cats (6). Dogs and cats with discrete intestinal masses identified by ultrasonography without evidence of intestinal perforation or peritonitis, were included. A 2 portal technique was used; 1 portal was enlarged for insertion of the wound retraction device through which the intestine was examined as thoroughly as possible. The diseased portion of the intestine was exteriorized through the wound retractor and resection and anastomosis of the intestinal mass performed. Of the 8 animals, laparoscopic-assisted intestinal resection and anastomosis through the wound retractor was performed in 2 dogs and 3 cats. In 3 cats, based on either location or extent of the lesion, 2 were converted to laparoscopic-assisted intestinal biopsies and 1 to an open colocolostomy. No other intra- or perioperative complications were encountered and all animals survived to discharge. Laparoscopic-assisted intestinal resection and anastomosis can be performed in select canine and feline patients with modestly sized, discrete intestinal masses. © Copyright 2011 by The American College of Veterinary Surgeons.

  2. Total artificial heart implantation for biventricular failure due to eosinophilic myocarditis.

    Science.gov (United States)

    Kawabori, Masashi; Kurihara, Chitaru; Miller, Yair; Heck, Kent A; Bogaev, Roberta C; Civitello, Andrew B; Cohn, William E; Frazier, O H; Morgan, Jeffrey A

    2017-09-01

    Idiopathic hypereosinophilic syndrome is a condition of unknown etiology characterized by proliferation of eosinophils and their infiltration into tissues. Although cardiac involvement is rare, eosinophilic myocarditis can lead to life-threating fulminant congestive heart failure. Treatment of patients with eosinophilic myocarditis is challenging as heart failure can be caused by biventricular dysfunction. To our knowledge, this is the first case reported in the literature describing a patient with acute severe biventricular heart failure caused by eosinophilic myocarditis with mural left ventricular apical thrombus who was successfully treated with implantation of a total artificial heart as a bridge to heart transplant.

  3. Bioartificial liver assist devices in support of patients with liver failure.

    Science.gov (United States)

    Patzer II, John F; Lopez, Roberto C; Zhu, Yue; Wang, Zi-Fa; Mazariegos, George V; Fung, John J

    2002-02-01

    Bioartificial liver assist devices (BALs) offer an opportunity for critical care physicians and transplant surgeons to stabilize patients prior to orthotopic liver transplantation. Such devices may also act as a bridge to transplant, providing liver support to patients awaiting transplant, or as support for patients post living-related donor transplant. Four BAL devices that rely on hepatocytes cultured in hollow fiber membrane cartridges (Circe Biomedical HepatAssist(r), Vitagen ELADTM, Gerlach BELS, and Excorp Medical BLSS) are currently in various stages of clinical evaluation. Comparison of the four devices shows that several unique approaches based upon the same overall system architecture are possible. Preliminary results of the Excorp Medical BLSS Phase I safety evaluation at the University of Pittsburgh, after treating four patients (F, 41, acetominophen-induced, two support periods; M, 50, Wilson's disease, one support period; F, 53, acute alcoholic hepatitis, two support periods; F, 24, chemotherapy-induced, one support period, are presented. All patients presented with hypoglycemia and transient hypotension at the start of extracorporeal perfusion. Hypoglycemia was treated by IV dextrose and the transient hypotension responded positively to IV fluid bolus. Heparin anticoagulation was used only in the second patient. No serious or adverse events were noted in the four patients. Moderate Biochemical response to support was noted in all patients. More complete characterization of the safety of the BLSS requires completion of the Phase I safety evaluation.

  4. Ab initio assisted process modeling for Si-based nanoelectronic devices

    International Nuclear Information System (INIS)

    Windl, Wolfgang

    2005-01-01

    In this paper, we discuss concepts and examples of ab initio calculations assisting physics-based process simulation. We focus on how to determine diffusion and reaction constants, where modern methods such as the nudged elastic band method allow a systematic and reliable search for the minimum energy migration path and barrier. We show that once the saddle point is determined, the underlying harmonic transition state theory also allows to calculate the prefactors. The discussed examples include nitrogen diffusion, boron deactivation and boron interface segregation. Finally, some concepts are discussed for future device technologies such as molecular devices, where the currently prevalent multiscale approach (kinetic parameters used in higher level models like diffusion-reaction or kinetic Monte Carlo modeling) would not be sensible anymore. As an example, we described the ab initio temperature-accelerated dynamics modeling of contact formation in carbon nanotube devices

  5. A Numerical Analysis of Phononic-Assisted Control of Ultrasound Waves in Acoustofluidic Device

    DEFF Research Database (Denmark)

    Moiseyenko, Rayisa; Bruus, Henrik

    2015-01-01

    and streaming has received much attention, since it relies solely on mechanical properties such as particle size and contrast in density and compressibility. We present a theoretical study of phononic-assisted control of ultrasound waves in acoustofluidic devices. We propose the use of phononic crystal...... diffractors, which can be introduced in acoustofluidic structures. These diffractors can be applied in the design of efficient resonant cavities, directional sound waves for new types of particle sorting methods, or acoustically controlled deterministic lateral displacement. The PnC-diffractor-based devices...... can be made configurable, by embedding the diffractors, all working at the same excitation frequency but with different resulting diffraction patterns, in exchangeable membranes on top of the device....

  6. Stroke rehabilitation: assistive technology devices and environmental modifications following primary rehabilitation in hospital--a therapeutic perspective

    DEFF Research Database (Denmark)

    Sørensen, Hanne Vinkel; Lendal, Susie; Schultz-Larsen, Kirsten

    2003-01-01

    The aim of this article is to describe the need for assistive devices and environmental modifications among long-living stroke survivors and to investigate if the need is continued and growing over time. The study sample of 155 consecutive stroke patients with stroke-related impairment, discharged...... home from three hospitals in Copenhagen from 1996 through 1998, constituted 20% of the total population of stroke survivors in this area. The results showed that 75% of these patients were provided with assistive devices and/or environmental modifications at discharge. Six months after discharge...... be required in order to target stroke survivors' changing needs for assistive devices and environmental modifications....

  7. Cross-cultural adaptation of the psychosocial impact of assistive device scale (PIADS) for Puerto Rican assistive technology users.

    Science.gov (United States)

    Orellano, Elsa M; Jutai, Jeffrey W

    2013-01-01

    Assistive technology (AT) is important for individuals with disabilities' independence and participation in daily life, and there is a lack of valid AT outcome tools for the Puerto Rican population. This pilot study examined the content validity of a new adaptation of the Psychosocial Impact of Assistive Device Scale (PIADS): the Puerto Rican-Spanish PIADS (PR-PIADS). Following standard procedures, the cultural adaptation methodology included a bilingual multidisciplinary committee review of the original (English language) and Spanish versions of the PIADS and pilot testing of the preliminary version of the PR-PIADS with 20 AT users. The committee recommended a total of 58 semantic and conceptual modifications of the Spanish PIADS. Pilot data analysis resulted in 4 additional semantic and conceptual modifications of items that did not reach the minimum content validity ratio of 0.42 for a panel composed by 20 members: competence (0), efficiency (-0.6), performance (-0.95), and eagerness to take chances (-0.6). This pilot study demonstrated evidence of initial content validity of the PR-PIADS. Future research is required before using this tool with greater confidence to address the construct validity and reliability that are also critical to a successful cultural adaptation.

  8. Perioperative management of calves undergoing implantation of a left ventricular assist device.

    Science.gov (United States)

    Wilson, D V; Kantrowitz, A; Pacholewicz, J; Salat, O; Paules, B R; Zhou, Y; Dawe, E J

    2000-01-01

    To describe perioperative management of calves that underwent left lateral thoracotomy, aortic cross-clamping, partial left heart bypass and implantation of a left ventricular assist device. A total of 43 healthy castrated male calves, weighing 121 +/- 24 kg. Diazepam (mean +/- SD, 0.26 +/- 0.07 mg/kg), ketamine (5.9 +/- 2.17 mg/kg) and isoflurane were used in the anesthetic management of calves undergoing implantation of a left ventricular assist device in the descending thoracic aorta. Other adjunctive agents administered were fentanyl (11 +/- 5.4 microg/kg), lidocaine (4.9 +/- 3.19 mg/kg), bupivacaine (0.75%) and butorphanol (0.49 +/- 0.13 mg/kg). None of the calves regurgitated at induction or during intubation. A tube was used to drain the rumen and prevent bloat during the procedure. Partial left heart bypass was used to perfuse the caudal half of the body during the period of aortic cross clamp and device implantation. Initial mean systemic blood pressure was 96 +/- 25 mm Hg, and pressures measured in the auricular artery increased during aortic cross-clamping and bypass. Vasoconstrictor therapy was required to treat caudal arterial hypotension during the procedure in 9 calves. Mean systemic arterial pressures returned to baseline values by the end of the anesthetic period. Initial mean pulmonary arterial pressures (PAP) were 22 +/- 3 mm Hg. A significant but transient increase in pulmonary arterial pressure occurred after both heparin and protamine administration. The described anesthetic protocol was effective for thoracotomy and implantation of an intra-aortic left ventricular assist device in normal calves. Partial left ventricular bypass was a useful adjunct during the period of aortic cross clamp. The doses of heparin and protamine administered were effective. Responsibility to monitor oxygenation of the cranial half of the animal continues during the bypass period as hypoxemia due to pulmonary dysfunction will not be detected by the perfusionist.

  9. Physical interface dynamics alter how robotic exosuits augment human movement: implications for optimizing wearable assistive devices.

    Science.gov (United States)

    Yandell, Matthew B; Quinlivan, Brendan T; Popov, Dmitry; Walsh, Conor; Zelik, Karl E

    2017-05-18

    Wearable assistive devices have demonstrated the potential to improve mobility outcomes for individuals with disabilities, and to augment healthy human performance; however, these benefits depend on how effectively power is transmitted from the device to the human user. Quantifying and understanding this power transmission is challenging due to complex human-device interface dynamics that occur as biological tissues and physical interface materials deform and displace under load, absorbing and returning power. Here we introduce a new methodology for quickly estimating interface power dynamics during movement tasks using common motion capture and force measurements, and then apply this method to quantify how a soft robotic ankle exosuit interacts with and transfers power to the human body during walking. We partition exosuit end-effector power (i.e., power output from the device) into power that augments ankle plantarflexion (termed augmentation power) vs. power that goes into deformation and motion of interface materials and underlying soft tissues (termed interface power). We provide empirical evidence of how human-exosuit interfaces absorb and return energy, reshaping exosuit-to-human power flow and resulting in three key consequences: (i) During exosuit loading (as applied forces increased), about 55% of exosuit end-effector power was absorbed into the interfaces. (ii) However, during subsequent exosuit unloading (as applied forces decreased) most of the absorbed interface power was returned viscoelastically. Consequently, the majority (about 75%) of exosuit end-effector work over each stride contributed to augmenting ankle plantarflexion. (iii) Ankle augmentation power (and work) was delayed relative to exosuit end-effector power, due to these interface energy absorption and return dynamics. Our findings elucidate the complexities of human-exosuit interface dynamics during transmission of power from assistive devices to the human body, and provide insight into

  10. Network-Assisted Distributed Fairness-Aware Interference Coordination for Device-to-Device Communication Underlaid Cellular Networks

    Directory of Open Access Journals (Sweden)

    Francis Boabang

    2017-01-01

    Full Text Available Device-to-device (D2D communication underlaid cellular network is considered a key integration feature in future cellular network. However, without properly designed interference management, the interference from D2D transmission tends to degrade the performance of cellular users and D2D pairs. In this work, we proposed a network-assisted distributed interference mitigation scheme to address this issue. Specifically, the base station (BS acts as a control agent that coordinates the cross-tier interference from D2D transmission through a taxation scheme. The cotier interference is controlled by noncooperative game amongst D2D pairs. In general, the outcome of noncooperative game is inefficient due to the selfishness of each player. In our game formulation, reference user who is the victim of cotier interference is factored into the payoff function of each player to obtain fair and efficient outcome. The existence, uniqueness of the Nash Equilibrium (NE, and the convergence of the proposed algorithm are characterized using Variational Inequality theory. Finally, we provide simulation results to evaluate the efficiency of the proposed algorithm.

  11. Management issues during HeartWare left ventricular assist device implantation and the role of transesophageal echocardiography

    Directory of Open Access Journals (Sweden)

    Sanjay Orathi Patangi

    2013-01-01

    Full Text Available Left ventricular assist devices (LVAD are increasingly used for mechanical circulatory support of patients with severe heart failure, primarily as a bridge to heart transplantation. Transesophageal echocardiography (TEE plays a major role in the clinical decision making during insertion of the devices and in the post-operative management of these patients. The detection of structural and device-related mechanical abnormalities is critical for optimal functioning of assist device. In this review article, we describe the usefulness of TEE for optimal perioperative management of patients presenting for HeartWare LVAD insertion.

  12. An accelerometry-based comparison of 2 robotic assistive devices for treadmill training of gait.

    Science.gov (United States)

    Regnaux, Jean-Philippe; Saremi, Kaveh; Marehbian, Jon; Bussel, Bernard; Dobkin, Bruce H

    2008-01-01

    Two commercial robotic devices, the Gait Trainer (GT) and the Lokomat (LOKO), assist task-oriented practice of walking. The gait patterns induced by these motor-driven devices have not been characterized and compared. A healthy participant chose the most comfortable gait pattern on each device and for treadmill (TM) walking at 1, 2 (maximum for the GT), and 3 km/h and over ground at similar speeds. A system of accelerometers on the thighs and feet allowed the calculation of spatiotemporal features and accelerations during the gait cycle. At the 1 and 2 km/h speed settings, single-limb stance times were prolonged on the devices compared with overground walking. Differences on the LOKO were decreased by adjusting the hip and knee angles and step length. At the 3 km/h setting, the LOKO approximated the participant's overground parameters. Irregular accelerations and decelerations from toe-off to heel contact were induced by the devices, especially at slower speeds. The LOKO and GT impose mechanical constraints that may alter leg accelerations-decelerations during stance and swing phases, as well as stance duration, especially at their slower speed settings, that are not found during TM and overground walking. The potential impact of these perturbations on training to improve gait needs further study.

  13. Rapid prototyping of 2D glass microfluidic devices based on femtosecond laser assisted selective etching process

    Science.gov (United States)

    Kim, Sung-Il; Kim, Jeongtae; Koo, Chiwan; Joung, Yeun-Ho; Choi, Jiyeon

    2018-02-01

    Microfluidics technology which deals with small liquid samples and reagents within micro-scale channels has been widely applied in various aspects of biological, chemical, and life-scientific research. For fabricating microfluidic devices, a silicon-based polymer, PDMS (Polydimethylsiloxane), is widely used in soft lithography, but it has several drawbacks for microfluidic applications. Glass has many advantages over PDMS due to its excellent optical, chemical, and mechanical properties. However, difficulties in fabrication of glass microfluidic devices that requires multiple skilled steps such as MEMS technology taking several hours to days, impedes broad application of glass based devices. Here, we demonstrate a rapid and optical prototyping of a glass microfluidic device by using femtosecond laser assisted selective etching (LASE) and femtosecond laser welding. A microfluidic droplet generator was fabricated as a demonstration of a microfluidic device using our proposed prototyping. The fabrication time of a single glass chip containing few centimeter long and complex-shaped microfluidic channels was drastically reduced in an hour with the proposed laser based rapid and simple glass micromachining and hermetic packaging technique.

  14. The Ventricular Assist Device in the Life of the Child: A Phenomenological Pediatric Study

    Science.gov (United States)

    van Manen, Michael A.

    2017-01-01

    What is it like for a child to live with an artificial heart? The use of some medical therapies in children requires developmental considerations, is associated with psychosocial consequences, and calls for ethical sensitivities. A critical case is the ventricular assist device (VAD), a mechanical pump used to support the functioning of a failing heart. As a pediatric therapy, the device can be used as a temporary solution for poor heart function, a bridge to transplantation or recovery, or as a destination therapy. While the mechanical-technical operation of the VAD is well understood, the clinical-technical aspects of young people living with this device are largely unexplored. Drawing on interviews of school-aged children, the aim of this phenomenological study is to explore how a VAD may structure or condition a child’s meaningful experience of their world outside the hospital. The driveline of an implanted VAD is the peripheral attachment, extruding through the skin to connect the controller-power supply. The materiality of the device may be interruptive, restrictive, and disturbing to the psycho-physical being and sense of self-identity of the child as a child. And while a child equipped with a VAD is not necessarily conspicuous among other children, the child may experience the device as an exposing presence, while living with the worry of a caregiver who takes on the role not simply of parent but of watchful health professional. A phenomenological understanding of the VAD should assist parents and caregiving health professionals knowing how to deal with specific issues arising in the life of the VAD child. PMID:28682718

  15. The Ventricular Assist Device in the Life of the Child: A Phenomenological Pediatric Study.

    Science.gov (United States)

    van Manen, Michael A

    2017-05-01

    What is it like for a child to live with an artificial heart? The use of some medical therapies in children requires developmental considerations, is associated with psychosocial consequences, and calls for ethical sensitivities. A critical case is the ventricular assist device (VAD), a mechanical pump used to support the functioning of a failing heart. As a pediatric therapy, the device can be used as a temporary solution for poor heart function, a bridge to transplantation or recovery, or as a destination therapy. While the mechanical-technical operation of the VAD is well understood, the clinical-technical aspects of young people living with this device are largely unexplored. Drawing on interviews of school-aged children, the aim of this phenomenological study is to explore how a VAD may structure or condition a child's meaningful experience of their world outside the hospital. The driveline of an implanted VAD is the peripheral attachment, extruding through the skin to connect the controller-power supply. The materiality of the device may be interruptive, restrictive, and disturbing to the psycho-physical being and sense of self-identity of the child as a child. And while a child equipped with a VAD is not necessarily conspicuous among other children, the child may experience the device as an exposing presence, while living with the worry of a caregiver who takes on the role not simply of parent but of watchful health professional. A phenomenological understanding of the VAD should assist parents and caregiving health professionals knowing how to deal with specific issues arising in the life of the VAD child.

  16. Fertility, pregnancy, and delivery after biventricular repair for pulmonary atresia with an intact ventricular septum

    NARCIS (Netherlands)

    Drenthen, Willem; Pieper, Petronella G.; Roos-Hesselink, Jollen W.; Zoon, Nicole; Voors, Adrlaan A.; Mulder, Barbara J. M.; van Dijk, Arie P. J.; Vliegen, Hubert W.; Sollie, Krystyna M.; Ebels, Tjark; van Veldhuisen, Dirk J.

    2006-01-01

    The objective of the present study to investigate fertility, pregnancy, and delivery in women with biventricular repair for pulmonary atresia with an intact ventricular septum (PAIVS). Using a nationwide registry (CONCOR), 37 patients with pulmonary atresia were identified, 6 of whom (aged 21 to 34

  17. Fertility, pregnancy, and delivery after biventricular repair for pulmonary atresia with an intact ventricular septum.

    NARCIS (Netherlands)

    Drenthen, W.; Pieper, P.G.; Roos-Hesselink, J.W.; Zoon, N.; Voors, A.A.; Mulder, B.J.M.; Dijk, A.P.J. van; Vliegen, H.W.; Sollie, K.M.; Ebels, T.; Veldhuisen, D.J. van

    2006-01-01

    The objective of the present study to investigate fertility, pregnancy, and delivery in women with biventricular repair for pulmonary atresia with an intact ventricular septum (PAIVS). Using a nationwide registry (CONCOR), 37 patients with pulmonary atresia were identified, 6 of whom (aged 21 to 34

  18. Impact of Tricuspid Valve Surgery at the Time of Left Ventricular Assist Device Insertion on Postoperative Outcomes

    OpenAIRE

    Dunlay, Shannon M.; Deo, Salil V.; Park, Soon J.

    2015-01-01

    Tricuspid regurgitation (TR) is common in patients with heart failure undergoing left ventricular assist device (LVAD) implantation. Whether the TR should be surgically managed at the time of LVAD surgery is controversial.

  19. A programmable and portable NMES device for drop foot correction and blood flow assist applications.

    Science.gov (United States)

    Breen, Paul P; Corley, Gavin J; O'Keeffe, Derek T; Conway, Richard; Olaighin, Gearóid

    2009-04-01

    The Duo-STIM, a new, programmable and portable neuromuscular stimulation system for drop foot correction and blood flow assist applications is presented. The system consists of a programmer unit and a portable, programmable stimulator unit. The portable stimulator features fully programmable, sensor-controlled, constant-voltage, dual-channel stimulation and accommodates a range of customized stimulation profiles. Trapezoidal and free-form adaptive stimulation intensity envelope algorithms are provided for drop foot correction applications, while time dependent and activity dependent algorithms are provided for blood flow assist applications. A variety of sensor types can be used with the portable unit, including force sensitive resistor-based foot switches and MEMS-based accelerometer and gyroscope devices. The paper provides a detailed description of the hardware and block-level system design for both units. The programming and operating procedures for the system are also presented. Finally, functional bench test results for the system are presented.

  20. Wireless sEMG-Based Body-Machine Interface for Assistive Technology Devices.

    Science.gov (United States)

    Fall, Cheikh Latyr; Gagnon-Turcotte, Gabriel; Dube, Jean-Francois; Gagne, Jean Simon; Delisle, Yanick; Campeau-Lecours, Alexandre; Gosselin, Clement; Gosselin, Benoit

    2017-07-01

    Assistive technology (AT) tools and appliances are being more and more widely used and developed worldwide to improve the autonomy of people living with disabilities and ease the interaction with their environment. This paper describes an intuitive and wireless surface electromyography (sEMG) based body-machine interface for AT tools. Spinal cord injuries at C5-C8 levels affect patients' arms, forearms, hands, and fingers control. Thus, using classical AT control interfaces (keypads, joysticks, etc.) is often difficult or impossible. The proposed system reads the AT users' residual functional capacities through their sEMG activity, and converts them into appropriate commands using a threshold-based control algorithm. It has proven to be suitable as a control alternative for assistive devices and has been tested with the JACO arm, an articulated assistive device of which the vocation is to help people living with upper-body disabilities in their daily life activities. The wireless prototype, the architecture of which is based on a 3-channel sEMG measurement system and a 915-MHz wireless transceiver built around a low-power microcontroller, uses low-cost off-the-shelf commercial components. The embedded controller is compared with JACO's regular joystick-based interface, using combinations of forearm, pectoral, masseter, and trapeze muscles. The measured index of performance values is 0.88, 0.51, and 0.41 bits/s, respectively, for correlation coefficients with the Fitt's model of 0.75, 0.85, and 0.67. These results demonstrate that the proposed controller offers an attractive alternative to conventional interfaces, such as joystick devices, for upper-body disabled people using ATs such as JACO.

  1. An optimal controller for an electric ventricular-assist device: theory, implementation, and testing.

    Science.gov (United States)

    Klute, G K; Tasch, U; Geselowitz, D B

    1992-04-01

    This paper addresses the development and testing of an optimal position feedback controller for the Penn State electric ventricular-assist device (EVAD). The control law is designed to minimize the expected value of the EVAD's power consumption for a targeted patient population. The closed-loop control law is implemented on an Intel 8096 microprocessor and in vitro test runs show that this controller improves the EVAD's efficiency by 15-21%, when compared with the performance of the currently used feedforward control scheme.

  2. Is exercise training safe and beneficial in patients receiving left ventricular assist device therapy?

    Science.gov (United States)

    Alsara, Osama; Perez-Terzic, Carmen; Squires, Ray W; Dandamudi, Sanjay; Miranda, William R; Park, Soon J; Thomas, Randal J

    2014-01-01

    Because a limited number of patients receive heart transplantation, alternative therapies, such as left ventricular assist device (LVAD) therapy, have emerged. Published studies have shown that LVAD implantation, by itself, improves exercise tolerance to the point where it is comparable to those with mild heart failure. The improvement in exercise capacity is maximally achieved 12 weeks after LVAD therapy and can continue even after explantation of the device. This effect varies, depending on the type of LVAD and exercise training. The available data in the literature on safety and benefits of exercise training in patients after LVAD implantation are limited, but the data that are available suggest that training trends to be safe and have an impact on exercise capacity in LVAD patients. Although no studies were identified on the role of cardiac rehabilitation programs in the management of LVAD patients, it appears that cardiac rehabilitation programs offer an ideal setting for the provision of supervised exercise training in this patient group.

  3. Identification of tasks performed by stroke patients using a mobility assistive device

    DEFF Research Database (Denmark)

    Hester, Todd; Sherrill, Delsey M; Hamel, Mathieu

    2006-01-01

    of these devices. In this study, we propose the use of wearable sensors to identify tasks performed by stroke patients with a mobility assistive device. Subjects performed ten tasks with a three-axis accelerometer attached to their ankle and a neural network was trained to identify the task being performed...... tasks associated with the use of a cane. Therefore, we envision that the methodology presented in this paper could be used to evaluate the use of a cane in the context of the task being performed........ Results from 15 stroke patients indicated that these motor tasks can be reliably identified with a median sensitivity of 90 % at a median specificity of 95%. These results indicate that it is possible to use a single module with a three-axis accelerometer attached to the ankle to reliably identify motor...

  4. Evolution of general surgical problems in patients with left ventricular assist devices.

    Science.gov (United States)

    McKellar, Stephen H; Morris, David S; Mauermann, William J; Park, Soon J; Zietlow, Scott P

    2012-11-01

    Left ventricular assist devices (LVADs) are increasingly used to treat patients with end-stage heart failure. These patients may develop acute noncardiac surgical problems around the time of LVAD implantation or, as survival continues to improve, chronic surgical problems as ambulatory patients remote from the LVAD implant. Previous reports of noncardiac surgical problems in LVAD patients included patients with older, first-generation devices and do not address newer, second-generation devices. We describe the frequency and management of noncardiac surgical problems encountered during LVAD support with these newer-generation devices to assist noncardiac surgeons involved in the care of patients with LVADs. We retrospectively reviewed the medical records of consecutive patients receiving LVADs at our institution. We collected data for any consultation by noncardiac surgeons within the scope of general surgery during LVAD support and subsequent treatment. Ninety-nine patients received implantable LVADs between 2003 and 2009 (first-generation, n = 19; second-generation, n = 80). Excluding intestinal hemorrhage, general surgical opinions were rendered for 34 patients with 49 problems, mostly in the acute recovery phase after LVAD implantation. Of those, 27 patients underwent 28 operations. Respiratory failure and intra-abdominal pathologies were the most common problems addressed, and LVAD rarely precluded operation. Patients with second-generation LVADs were more likely to survive hospitalization (P = .04) and develop chronic, rather than emergent, surgical problems. Patients with LVADs frequently require consultation from noncardiac surgeons within the scope of general surgeons and often require operation. Patients with second-generation LVADs are more likely to become outpatients and develop more elective surgical problems. Noncardiac surgeons will be increasingly involved in caring for patients with LVADs and should anticipate the problems unique to this patient

  5. Impact of long term left ventricular assist device therapy on donor allocation in cardiac transplantation.

    Science.gov (United States)

    Uriel, Nir; Jorde, Ulrich P; Woo Pak, Sang; Jiang, Jeff; Clerkin, Kevin; Takayama, Hiroo; Naka, Yoshifumi; Schulze, P Christian; Mancini, Donna M

    2013-02-01

    Left Ventricular Assist Devices (LVAD) are increasingly used as a bridge to transplant (BTT) for patients with advanced congestive heart failure (CHF) and are assigned United Network for Organ Sharing (UNOS) high priority status (1B or 1A). The purpose of our study was asses the effect of organ allocation in the era of continuous flow pumps. A retrospective chart review was performed of all patients transplanted between 1/2001-1/2011 at Columbia University Medical Center. Seven hundred twenty six adult heart transplantations were performed. Two hundred seventy four BTT patients were implanted with LVAD; of which 227 patients were transplanted. Sixty three patients were transplanted as UNOS-1B, while 164 were transplanted as UNOS-1A (72%). Of these 164 patients, 65 were transplanted during their 30-day 1A period (43%) and 96 after upgrading to UNOS-1A for device complication (56%). For 452 non-device patients 139 (31%) were transplanted as UNOS-1A, 233 as UNOS-1B (52%), and 80 as UNOS-2 (17%). The percentage of patients bridged with LVAD increased from 19% in 2001 to 64% in 2010 while the number transplanted during their 30 day 1A grace period declined from 57% in 2005 to 16% in 2011; i.e. 84% of BTT patients in 2011 needed more than 30 days 1A time to be transplanted. Most LVAD patients are now transplanted while suffering device complication. There was no difference in post transplant survival between LVAD patients transplanted as UNOS 1B, 1A grace period or for a device complication As wait time for cardiac transplantation increased the percentage of patients being bridged to transplant with an LVAD has increased with the majority of them transplanted in the setting of device complication. Copyright © 2013 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  6. Development of a power-assisted lifting device for construction and periodic inspection

    International Nuclear Information System (INIS)

    Hayatsu, M.; Yamada, M.; Takasu, H.; Tagawa, Y.; Kajiwara, K.

    2001-01-01

    This study focuses on the control system design and control performance of a power-assisted lifting device. The device consists of several electric chain-blocks, each controlled by force sensors and a CPU. The mechanism is as follows: (1) Force sensors detect any chain tension changes (by human force), (2) The CPU calculates the required output, (3) Electric chain-blocks move the object in the intended direction. The feature of this device is that it does not require any information related to the suspension points of the electric chain-blocks. The controller was designed using the H method, which considers disturbances and aims to provide robust stability under the operation conditions of construction verified through experiments using a 700 kg steel dummy mass (control object) suspended by four electric chain-blocks. In the experiments, the controller, which was designed using the H method, was compared to the PI controller method, and the effectiveness of the H controller was proven. A control object could be moved, translated, and rotated by human force (of less than 10 kg). Positioning performance errors were suppressed to less than 0.5 mm, and operation time was reduced by about 50%. This device will improve working efficiency and rationalize lifting operations in nuclear power plants. (author)

  7. Prologue: ventricular assist devices and total artificial hearts. A historical perspective.

    Science.gov (United States)

    Frazier, O H

    2003-02-01

    In the 1960s, when LVADs and TAHs were introduced into clinical use, researchers estimated that, with this technology, the problem of heart failure could be solved within 20 years. Unfortunately, the evolution of these devices has taken much longer than anticipated. Nevertheless, significant advances have been achieved in both cardiac assistance and replacement, and today's cardiac surgeons have a wide range of devices from which to choose (Table 4). This progress has largely been due to the support of the NHLBI, especially the Devices and Technology Division headed by John Watson, and of the devoted commitment of the investigators. Because of the long-term commitment required for both basic and clinical research, commercial medical technology companies are unable to assume this burden. Advances in mechanical circulatory support and replacement have benefited numerous patients worldwide who would otherwise have died of heart failure, and devices now exist for use as bridges to recovery, bridges to transplant, and destination therapy. The current challenge is to refine what we have and to apply these technologies to broader patient populations with maximal safety and at a reasonable cost.

  8. An assistance device to help people with trunk impairment maintain posture.

    Science.gov (United States)

    Ogura, Tomoka; Itami, Taku; Yano, Ken'ichi; Mori, Ichidai; Kameda, Kazuhiro

    2017-07-01

    People with trunk impairment cannot lean forward because of the dysfunction of the trunk resulting from events such as cervical cord injury (CCI). It is therefore difficult for such people to work at a table because they may easily fall from their wheelchair, and it is also hard for them to return to their original position. This limits the activities of daily living (ADLs) of people with trunk impairment. These problems can be solved to some extent with equipment such as a wheelchair belt or a spinal orthosis that can help the person to maintain his or her posture. However, people cannot move freely with this equipment. Furthermore, if this equipment is used for a long time, there is a risk of physical pain and skin issues. In this study, we developed a device that assists the trunk of people with trunk impairment when they lean forward. This device supports people with trunk impairment so that they may take their meals at the table and prevents them from falling over their wheelchair without hindering their daily performance when they are sitting normally. The effectiveness of our proposed device was verified by experiments involving having a meal, operating a wheelchair, and colliding with a curb. Our device can help people with trunk impairment by improving their ADLs and quality of life (QOL).

  9. Anchoring in Destination-Therapy Left Ventricular Assist Device Decision Making: A Mechanical Turk Survey.

    Science.gov (United States)

    Paine, Arcadia M; Allen, Larry A; Thompson, Jocelyn S; McIlvennan, Colleen K; Jenkins, Amy; Hammes, Andrew; Kroehl, Miranda; Matlock, Daniel D

    2016-11-01

    People with end-stage heart failure may have to decide about destination-therapy left ventricular assist device (DT-LVAD). Individuals facing difficult decisions often rely on heuristics, such as anchoring, which predictably bias decision outcomes. We aimed to investigate whether showing a larger historical Heartmate XVE creates an anchoring effect, making the smaller Heartmate II (HMII) appear more favorable. With the use of Amazon Mechanical Turk, participants watched videos asking them to imagine themselves dying of end-stage heart failure, then were presented the option of LVAD as potentially life-prolonging therapy. Participants were randomized to a control group who were only shown the HMII device, and the intervention group who saw the XVE device before the HMII. Participants then completed surveys. A total of 487 participants completed the survey (control = 252; intervention = 235); 79% were affect likelihood of accepting the LVAD, it did affect device perception. This article highlights an important point with clinical implications: factors such as anchoring have the potential to inappropriately influence perceptions and decisions and should be carefully considered in research and practice. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Development of a power-assisted lifting device for construction and periodic inspection

    Energy Technology Data Exchange (ETDEWEB)

    Hayatsu, M.; Yamada, M.; Takasu, H. [Hitachi Plant Engineering and Construction, Chiba-ken (Japan); Tagawa, Y. [Tokyo Univ. of Agriculture and Technology (Japan); Kajiwara, K. [National Research Institute for Earth Science and Disaster Prevention, Tokyo (Japan)

    2001-07-01

    This study focuses on the control system design and control performance of a power-assisted lifting device. The device consists of several electric chain-blocks, each controlled by force sensors and a CPU. The mechanism is as follows: (1) Force sensors detect any chain tension changes (by human force), (2) The CPU calculates the required output, (3) Electric chain-blocks move the object in the intended direction. The feature of this device is that it does not require any information related to the suspension points of the electric chain-blocks. The controller was designed using the H method, which considers disturbances and aims to provide robust stability under the operation conditions of construction verified through experiments using a 700 kg steel dummy mass (control object) suspended by four electric chain-blocks. In the experiments, the controller, which was designed using the H method, was compared to the PI controller method, and the effectiveness of the H controller was proven. A control object could be moved, translated, and rotated by human force (of less than 10 kg). Positioning performance errors were suppressed to less than 0.5 mm, and operation time was reduced by about 50%. This device will improve working efficiency and rationalize lifting operations in nuclear power plants. (author)

  11. An Examination of the Impact of an Assistive Technology Device on the Quality of Adult/Young Child Interactions

    Science.gov (United States)

    Plunkett, Diane M.

    2013-01-01

    The purpose of this study was to gain greater understanding of the potential benefits of assistive technology (AT) devices on young children's social development. Specifically, changes to the quality of the adult/young child social interactions as a function of the child's access to and use of his/her personal AT device was examined. Using a…

  12. "Pseudo" Faraday cage: a solution for telemetry link interaction between a left ventricular assist device and an implantable cardioverter defibrillator.

    Science.gov (United States)

    Jacob, Sony; Cherian, Prasad K; Ghumman, Waqas S; Das, Mithilesh K

    2010-09-01

    Patients implanted with left ventricular assist devices (LVAD) may have implantable cardioverter defibrillators (ICD) implanted for sudden cardiac death prevention. This opens the possibility of device-device communication interactions and thus interferences. We present a case of such interaction that led to ICD communication failure following the activation of an LVAD. In this paper, we describe a practical solution to circumvent the communication interference and review the communication links of ICDs and possible mechanisms of ICD-LVAD interactions.

  13. Extracorporeal Life Support Bridge to Ventricular Assist Device: The Double Bridge Strategy.

    Science.gov (United States)

    Marasco, Silvana F; Lo, Casey; Murphy, Deirdre; Summerhayes, Robyn; Quayle, Margaret; Zimmet, Adam; Bailey, Michael

    2016-01-01

    In patients requiring left ventricular assist device (LVAD) support, it can be difficult to ascertain suitability for long-term mechanical support with LVAD and eventual transplantation. LVAD implantation in a shocked patient is associated with increased morbidity and mortality. Interest is growing in the utilization of extracorporeal life support (ECLS) as a bridge-to-bridge support for these critically unwell patients. Here, we reviewed our experience with ECLS double bridging. We hypothesized that ECLS double bridging would stabilize end-organ dysfunction and reduce ventricular assist device (VAD) implant perioperative mortality. We conducted a retrospective review of prospectively collected data for 58 consecutive patients implanted with a continuous-flow LVAD between January 2010 and December 2013 at The Alfred Hospital, Melbourne, Victoria, Australia. Twenty-three patients required ECLS support pre-LVAD while 35 patients underwent LVAD implantation without an ECLS bridge. Preoperative morbidity in the ECLS bridge group was reflected by increased postoperative intensive care duration, blood loss, blood product use, and postoperative renal failure, but without negative impact upon survival when compared with the no ECLS group. ECLS stabilization improved end-organ function pre-VAD implant with significant improvements in hepatic and renal dysfunction. This series demonstrates that the use of ECLS bridge to VAD stabilizes end-organ dysfunction and reduces VAD implant perioperative mortality from that traditionally reported in these "crash and burn" patients. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  14. Outcomes of patients with right ventricular failure on milrinone after left ventricular assist device implantation.

    Science.gov (United States)

    Tsiouris, Athanasios; Paone, Gaetano; Brewer, Robert J; Nemeh, Hassan W; Borgi, Jamil; Morgan, Jeffrey A

    2015-01-01

    Previous studies have grouped together both patients requiring right ventricular assist devices (RVADs) with patients requiring prolonged milrinone therapy after left ventricular assist device (LVAD) implantation. We retrospectively identified 149 patients receiving LVADs and 18 (12.1%) of which developed right ventricular (RV) failure. We then separated these patients into those requiring RVADs versus prolonged milrinone therapy. This included 10 patients who were treated with prolonged milrinone and eight patients who underwent RVAD placement. Overall, the RV failure group had worse survival compared with the non-RV failure cohort (p = 0.038). However, this was only for the subgroup of patients who required RVADs, who had a 1, 6, 12, and 24 month survival of 62.5%, 37.5%, 37.5%, and 37.5%, respectively, versus 96.8%, 92.1%, 86.7%, and 84.4% for patients without RV failure (p milrinone therapy for RV failure had similar survivals compared with patients without RV failure. In the RV failure group, age, preoperative renal failure, and previous cardiac surgery were predictors of the need for prolonged postoperative milrinone. As LVADs become a more widely used therapy for patients with refractory, end-stage heart failure, it will be important to reduce the incidence of RV failure, as it yields significant morbidity and increases cost.

  15. Older individuals' experiences during the assistive technology device service delivery process.

    Science.gov (United States)

    Gramstad, Astrid; Storli, Sissel Lisa; Hamran, Torunn

    2014-07-01

    Providing assistive technology devices to older individuals living in their ordinary homes is an important intervention to increase and sustain independence and to enable ageing at home. However, little is known about older individuals' experiences and needs in the assistive technology device (ATD) service delivery process. The purpose of this study was to investigate older individuals' experiences during the service delivery process of ATDs. Nine older individuals were interviewed three times each throughout the ATD service delivery process. The interviews were analysed within a hermeneutical phenomenological perspective. The results show that the service delivery process could be interpreted as an enigmatic journey and described using four themes: "hope and optimistic expectations", "managing after delivery or needing additional help", "having available help versus being abandoned", and "taking charge or putting up". The results emphasize the need for occupational therapists to maintain an individualized approach towards older clients throughout the service delivery process. The experiences of older individuals were diverse and related to expectations that were not necessarily articulated to the occupational therapist. The situation when the ATD is delivered to the client was highlighted by the clients as an important event with the potential to facilitate a successful service delivery process.

  16. Utilization of assistive devices for students with disabilities in the public schools

    Directory of Open Access Journals (Sweden)

    Carolina Bastos Plotegher

    2013-04-01

    Full Text Available Introduction: Assistive technology is an area of expanding knowledge in Brazil. Its use in school can help students with disabilities in performing important tasks to participate in different activities. Objectives: to report the experience of using assistive devices in the academic achievement of students with disabilities included in the regular school system of the municipality of Sao Carlos, state of Sao Paulo. Method: it was developed from an extension project conducted in 2010. Thirteen students with various types of disabilities participated in the project. The interventions were based on the School Function Assessment with the teachers to know the students’ difficulties. The students were also observed performing school tasks. Results: Forty-seven adaptations were made: thickeners, rings for zippers, slants, communication boards, non-slip mats, among others. Besides the adjustments, orientation regarding use of the devices was provided for teachers and persons responsible for the students. Conclusion: we believe that the project benefited the students, because it produced higher academic achievement and provided better school conditions for their school inclusion. For the undergraduate students of Occupational Therapy, the project enabled the dealing with real issues of inclusion and school interventions, thus approaching theory to practice.

  17. Environmental barriers to participation and facilitators for use of three types of assistive technology devices.

    Science.gov (United States)

    Widehammar, Cathrine; Lidström, Helene; Hermansson, Liselotte

    2017-08-07

    The aim was to compare the presence of environmental barriers to participation and facilitators for assistive technology (AT) use and study the relation between barriers and AT use in three different AT devices. A cross-sectional survey was conducted. Inclusion criteria were ≥one year of experience as a user of myoelectric prosthesis (MEP), powered mobility device (PMD), or assistive technology for cognition (ATC) and age 20-90 years. Overall, 156 participants answered the Swedish version of the Craig Hospital Inventory of Environmental Factors and a study-specific questionnaire on facilitating factors. Non-parametric tests were used for comparisons. Barriers to participation were lowest in MEP users (md=0.12; p>0.001), and highest in ATC users (md=1.56; p>0.001) with the least support for AT use (p>0.001 - p=0.048). A positive correlation between fewer barriers and higher use of MEP was seen (r=0.30, p=0.038). The greatest barriers to participation were Natural environment, Surroundings and Information, and the most support came from relatives and professionals. Support, training and education are vital in the use of AT. These factors may lead to a more sustained and prolonged use of AT and may enable increased participation. Future research should focus on interventions that meet the needs of people with cognitive disabilities.

  18. Laparoscopy-assisted percutaneous endoscopic gastrostomy using a "Funada-kit II" device.

    Science.gov (United States)

    Takahashi, Toshiaki; Miyano, Go; Shiyanagi, Satoko; Lane, Geoffrey J; Yamataka, Atsuyuki

    2012-09-01

    We aimed at assessing the effect of using a "Funada-kit II" device during laparoscopy-assisted percutaneous endoscopic gastrostomy (Lap-PEG), by reviewing 29 cases of Lap-PEG we performed from 2001 to 2011. We started using the "Funada-kit II" (CREATE MEDIC CO., Kanagawa, Japan) device with two parallel needles to puncture the stomach and assist suturing the anterior gastric wall to the anterior abdominal wall during Lap-PEG in 2011 (F-PEG). By introducing a loop through the lumen of one needle which allows placement of a suture introduced through the lumen of the other needle. Once repeated, the stomach can be pexied at two points, approximately 2 cm apart. We compared Lap-PEG (n = 23) with F-PEG (n = 6) where the mean ages and weights at surgery and sex ratios were similar. All cases were uneventful without intraoperative complications, although one postoperative wound infection occurred in a Lap-PEG case. There were no differences in the duration of analgesia, time taken to commence tube feeding, and return to full feeding. However, mean operating time was significantly shorter in F-PEG (28.1 min) versus Lap-PEG (46.1 min) p < 0.05. As per results F-PEG would appear to be as safe as Lap-PEG, but much quicker.

  19. Prototype of a mechanical assistance device for the wrists' flexion-extension movement

    International Nuclear Information System (INIS)

    Politti, Julio C; Puglisi, Lisandro J; Farfan, Fernando D

    2007-01-01

    Using CMU actuators, a Prototype of Mechanical Assistance Device for the Wrist's Flexion Movement (PMA) was developed and probed in a mechanical model, in order to be implemented in a future as a dynamic powered orthosis or as a rehabilitation assistant instrument. Two Mayor Actuators conformed by three CMU actuators arranged in a series configuration, allows to an artificial hand to be placed in four predefined positions: 0 0 , 20 0 , 40 0 and 60 0 . The synchronism and control of the actuators is achieved with the Programmable Control Module (PCM). It is capable to drive up to six CMU actuators, and possess two different modes of execution: a Manual mode and an Exercise mode. In the Manual Mode, the position of the hand responds directly to the commands of the keyboard of the front panel, and in the Exercise mode, the hand realizes a repetitive and programmed movement. The prototype was tested in 100 positions in the Manual Mode and for 225 works cycles in the Exercise Mode. The relative repetition error was less than 5% for both test. This prototype only consumes 4,15W, which makes it possible to be powered by small rechargeable batteries, allowing its use as a portable device

  20. Intraoperative Transesophageal Echocardiography and Right Ventricular Failure After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Silverton, Natalie A; Patel, Ravi; Zimmerman, Josh; Ma, Jianing; Stoddard, Greg; Selzman, Craig; Morrissey, Candice K

    2018-02-15

    To determine whether intraoperative measures of right ventricular (RV) function using transesophageal echocardiography are associated with subsequent RV failure after left ventricular assist device (LVAD) implantation. Retrospective, nonrandomized, observational study. Single tertiary-level, university-affiliated hospital. The study comprised 100 patients with systolic heart failure undergoing elective LVAD implantation. Transesophageal echocardiographic images before and after cardiopulmonary bypass were analyzed to quantify RV function using tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (S'), fractional area change (FAC), RV global longitudinal strain, and RV free wall strain. A chart review was performed to determine which patients subsequently developed RV failure (right ventricular assist device placement or prolonged inotrope requirement ≥14 days). Nineteen patients (19%) subsequently developed RV failure. Postbypass FAC was the only measure of RV function that distinguished between the RV failure and non-RV failure groups (21.2% v 26.5%; p = 0.04). The sensitivity, specificity, and area under the curve of an abnormal RV FAC (failure after LVAD implantation were 84%, 20%, and 0.52, respectively. No other intraoperative measure of RV function was associated with subsequent RV failure. RV failure increased ventilator time, intensive care unit and hospital length of stay, and mortality. Intraoperative measures of RV function such as tricuspid annular plane systolic excursion, tricuspid annular systolic velocity, and RV strain were not associated with RV failure after LVAD implantation. Decreased postbypass FAC was significantly associated with RV failure but showed poor discrimination. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Pathology in patients with ventricular assist devices: a study of 21 autopsies, 24 ventricular apical core biopsies and 24 explanted hearts.

    Science.gov (United States)

    Rose, Alan G; Park, Soon J

    2005-01-01

    Ventricular assist devices (VADs) are used as a bridge to cardiac transplantation or as a permanent or sometimes temporary treatment for end stage heart failure. Our autopsy and surgical pathology experience with VADs prior to August 2002 was reviewed. Noted were patient's age, sex, underlying (UCOD) and proximate causes of death (PCOD), duration of VAD implantation, presence of native or prosthetic valvar disease and organ complications. Myocardium from biopsies and explanted hearts were blindly assessed for coagulative necrosis (CN), contraction bands (CB), myocytolysis (MC), increased eosinophilia (IE), myocyte waviness (MW) and fibrosis (F). Each was graded as either mild (score 1), moderate (score 2) or severe (score 3). Autopsy patients: Twenty-one patients, with mean age 55 years (range 10-73), comprised 10 women and 11 men. UCOD was ischemic disease in 16 patients, dilated cardiomyopathy in 4 and aortic valve disease in 1. The mean duration of VAD implantation was 125.7 days (range 1-1095 days, S.D.=253.6). Five patients had biventricular VADs, and 16 had LVAD only. Acquired aortic valve fusion was noted in three patients. PCOD was VAD related in six, donor heart problem in four, cerebrovascular accident in four, miscellaneous in three, pulmonary hypertension in two and aortic disease in two patients. Morbidity: local liver necrosis in seven, acquired aortic valve disease in four, gut infarction in three, abdominal aortic aneurysm in two and host cell assault against VAD porcine aortic valves in one case. Biopsies and explanted hearts: Twenty-four patients had a mean age of 53 years (range 38-68, S.D.=8.6). VADs were implanted for 177.8 days (range 7-593 days, S.D.=151.1). Comparison of histologic scores of biopsies with explanted hearts showed the following: CN 1.33 (S.D.=1.4)/0.21 (S.D.=0.66; P<.001); CB: 2.1 (S.D.=0.93)/0.83 (S.D.=0.28; NS); MC: 0.88 (S.D.=1.19)/0.13 (S.D.=0.34; P<.01); IE: 1.71 (S.D.=1.27)/0.38 (S.D.=0.65; NS); fibrosis: 1.08 (S.D.=1

  2. Early Right Ventricular Assist Device Use in Patients Undergoing Continuous-Flow Left Ventricular Assist Device Implantation: Incidence and Risk Factors From the Interagency Registry for Mechanically Assisted Circulatory Support.

    Science.gov (United States)

    Kiernan, Michael S; Grandin, E Wilson; Brinkley, Marshall; Kapur, Navin K; Pham, Duc Thinh; Ruthazer, Robin; Rame, J Eduardo; Atluri, Pavan; Birati, Edo Y; Oliveira, Guilherme H; Pagani, Francis D; Kirklin, James K; Naftel, David; Kormos, Robert L; Teuteberg, Jeffrey J; DeNofrio, David

    2017-10-01

    To investigate preimplant risk factors associated with early right ventricular assist device (RVAD) use in patients undergoing continuous-flow left ventricular assist device (LVAD) surgery. Patients in the Interagency Registry for Mechanically Assisted Circulatory Support who underwent primary continuous-flow-LVAD surgery were examined for concurrent or subsequent RVAD implantation within 14 days of LVAD. Risk factors for RVAD implantation and the combined end point of RVAD or death within 14 days of LVAD were assessed with stepwise logistic regression. We compared survival between patients with and without RVAD using Kaplan-Meier method and Cox proportional hazards modeling. Of 9976 patients undergoing continuous-flow-LVAD implantation, 386 patients (3.9%) required an RVAD within 14 days of LVAD surgery. Preimplant characteristics associated with RVAD use included interagency registry for mechanically assisted circulatory support patient profiles 1 and 2, the need for preoperative extracorporeal membrane oxygenation or renal replacement therapy, severe preimplant tricuspid regurgitation, history of cardiac surgery, and concomitant procedures other than tricuspid valve repair at the time of LVAD. Hemodynamic determinants included elevated right atrial pressure, reduced pulmonary artery pulse pressure, and reduced stroke volume. The final model demonstrated good performance for both RVAD implant (area under the curve, 0.78) and the combined end point of RVAD or death within 14 days (area under the curve, 0.73). Compared with patients receiving an isolated LVAD, patients requiring RVAD had decreased 1- and 6-month survival: 78.1% versus 95.8% and 63.6% versus 87.9%, respectively ( P The need for RVAD implantation after LVAD is associated with indices of global illness severity, markers of end-organ dysfunction, and profiles of hemodynamic instability. © 2017 American Heart Association, Inc.

  3. Self-Organizing Wearable Device Platform for Assisting and Reminding Humans in Real Time

    Directory of Open Access Journals (Sweden)

    Yu Jin Park

    2016-01-01

    Full Text Available Most older persons would prefer “aging in my place,” that is, to remain in good health and live independently in their own home as long as possible. For assisting the independent living of older people, the ability to gather and analyze a user’s daily activity data would constitute a significant technical advance, enhancing their quality of life. However, the general approach based on centralized server has several problems such as the usage complexity, the high price of deployment and expansion, and the difficulty in identifying an individual person. To address these problems, we propose a wearable device platform for the life assistance of older persons that automatically records and analyzes their daily activity without intentional human intervention or a centralized server (i.e., cloud server. The proposed platform contains self-organizing protocols, Delay-Tolerant Messaging system, knowledge-based analysis and alerting for daily activities, and a hardware platform that provides low power consumption. We implemented a prototype smart watch, called Personal Activity Assisting and Reminding (PAAR, as a testbed for the proposed platform, and evaluated the power consumption and the service time of example scenarios.

  4. Cross-cultural adaptation of the assistive technology device - Predisposition assessment (ATD PA) for use in Brazil (ATD PA Br).

    Science.gov (United States)

    Alves, Ana Cristina de Jesus; Matsukura, Thelma Simões; Scherer, Marcia J

    2017-02-01

    The purpose of this study is to conduct a cross-cultural adaptation of the Assistive Technology Device Predisposition Assessment (ATD PA) for use in Brazil. The selection of the Assistive Technology Device Predisposition Assessment (ATD PA) was determined by previous literature reviews of articles published in 2014 and 2016 in six databases with the terms "assistive device" or "assistive technology" or "self-help device" combined with "evidence-based practice" or "framework" or "measurement scale" or "model and outcome assessment". This review indicated that the conceptual model of Assistive Technology (AT) most discussed in the literature was the Matching Person and Technology (MPT) model, and this finding determined the selection of ATD PA as an assessment within the MPT portfolio of measures. The procedures for cross-cultural adaptation were as follows: Equivalence of Concept, Semantic and Operational. Five experts were asked to translate 725 items and these translations were evaluated and a high level of agreement was demonstrated. The Portuguese version, Avaliação de Tecnologia Assistiva - Predisposição ao Uso - ATD PA Br, was derived from the original version in English (ATD PA). The ATD PA Br will support professionals and people with disabilities in Brazil to better select AT devices according to the clients' needs. Implications for rehabilitation Provides a systematic way of selecting assistive technology devices for the use of individuals with disabilities according to the Brazilian reality. A systematic way of selecting the assistive technology that can help decrease the abandonment of the assistive technology use. The use of the Matching Person and Technology theorical model and of the assessment ATD PA Br is essential to guide the researches and clinical practice in Brazil.

  5. Electric poling-assisted additive manufacturing process for PVDF polymer-based piezoelectric device applications

    International Nuclear Information System (INIS)

    Lee, ChaBum; Tarbutton, Joshua A

    2014-01-01

    This paper presents a new additive manufacturing (AM) process to directly and continuously print piezoelectric devices from polyvinylidene fluoride (PVDF) polymeric filament rods under a strong electric field. This process, called ‘electric poling-assisted additive manufacturing or EPAM, combines AM and electric poling processes and is able to fabricate free-form shape piezoelectric devices continuously. In this process, the PVDF polymer dipoles remain well-aligned and uniform over a large area in a single design, production and fabrication step. During EPAM process, molten PVDF polymer is simultaneously mechanically stresses in-situ by the leading nozzle and electrically poled by applying high electric field under high temperature. The EPAM system was constructed to directly print piezoelectric structures from PVDF polymeric filament while applying high electric field between nozzle tip and printing bed in AM machine. Piezoelectric devices were successfully fabricated using the EPAM process. The crystalline phase transitions that occurred from the process were identified by using the Fourier transform infrared spectroscope. The results indicate that devices printed under a strong electric field become piezoelectric during the EPAM process and that stronger electric fields result in greater piezoelectricity as marked by the electrical response and the formation of sharper peaks at the polar β crystalline wavenumber of the PVDF polymer. Performing this process in the absence of an electric field does not result in dipole alignment of PVDF polymer. The EPAM process is expected to lead to the widespread use of AM to fabricate a variety of piezoelectric PVDF polymer-based devices for sensing, actuation and energy harvesting applications with simple, low cost, single processing and fabrication step. (paper)

  6. Validation of a laser-assisted wound measurement device in a wound healing model.

    Science.gov (United States)

    Constantine, Ryan S; Bills, Jessica D; Lavery, Lawrence A; Davis, Kathryn E

    2016-10-01

    In the treatment and monitoring of a diabetic or chronic wound, accurate and repeatable measurement of the wound provides indispensable data for the patient's medical record. This study aims to measure the accuracy of the laser-assisted wound measurement (LAWM) device against traditional methods in the measurement of area, depth and volume. We measured four 'healing' wounds in a Play-Doh(®) -based model over five subsequent states of wound healing progression in which the model was irregularly filled in to replicate the healing process. We evaluated the LAWM device against traditional methods including digital photograph assessment with National Institutes of Health ImageJ software, measurements of depth with a ruler and weight-to-volume assessment with dental paste. Statistical analyses included analysis of variance (ANOVA) and paired t-tests. We demonstrate that there are significantly different and nearly statistically significant differences between traditional ruler depth measurement and LAWM device measurement, but there are no statistically significant differences in area measurement. Volume measurements were found to be significantly different in two of the wounds. Rate of percentage change was analysed for volume and depth in the wound healing model, and the LAWM device was not significantly different than the traditional measurement technique. While occasionally inaccurate in its absolute measurement, the LAWM device is a useful tool in the clinician's arsenal as it reliably measures rate of percentage change in depth and volume and offers a potentially aseptic alternative to traditional measurement techniques. © 2014 The Authors. International Wound Journal © 2014 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  7. Mechanisms and clinical applications of the vacuum-assisted closure (VAC) Device: a review.

    Science.gov (United States)

    Venturi, Mark L; Attinger, Christopher E; Mesbahi, Ali N; Hess, Christopher L; Graw, Katherine S

    2005-01-01

    The use of sub-atmospheric pressure dressings, available commercially as the vacuum-assisted closure (VAC) device, has been shown to be an effective way to accelerate healing of various wounds. The optimal sub-atmospheric pressure for wound healing appears to be approximately 125 mm Hg utilizing an alternating pressure cycle of 5 minutes of suction followed by 2 minutes off suction. Animal studies have demonstrated that this technique optimizes blood flow, decreases local tissue edema, and removes excessive fluid from the wound bed. These physiologic changes facilitate the removal of bacteria from the wound. Additionally, the cyclical application of sub-atmospheric pressure alters the cytoskeleton of the cells in the wound bed, triggering a cascade of intracellular signals that increases the rate of cell division and subsequent formation of granulation tissue. The combination of these mechanisms makes the VAC device an extremely versatile tool in the armamentarium of wound healing. This is evident in the VAC device's wide range of clinical applications, including treatment of infected surgical wounds, traumatic wounds, pressure ulcers, wounds with exposed bone and hardware, diabetic foot ulcers, and venous stasis ulcers. VAC has also proven useful in reconstruction of wounds by allowing elective planning of the definitive reconstructive surgery without jeopardizing the wound or outcome. Furthermore, VAC has significantly increased the skin graft success rate when used as a bolster over the freshly skin-grafted wound. VAC is generally well tolerated and, with few contraindications or complications, is fast becoming a mainstay of current wound care.

  8. Mechanical circulatory assist device development at the Texas Heart Institute: a personal perspective.

    Science.gov (United States)

    Frazier, O H

    2014-01-01

    In December 2013, we performed our 1000th ventricular assist device implantation at the Texas Heart Institute. In my professional career, I have been fortunate to see the development of numerous mechanical circulatory support devices for the treatment of patients with advanced heart failure. In fact, most of the cardiac pumps in wide use today were developed in the Texas Heart Institute research laboratories in cooperation with the National Heart, Lung and Blood Institute or device innovators and manufacturers and implanted clinically at our partner St. Luke's Episcopal Hospital. My early involvement in this field was guided by my mentors, Dr Michael E. DeBakey and, especially, Dr Denton A. Cooley. Also, many of the advances are directly attributable to my ongoing clinical experience. What I learned daily in my surgical practice allowed me to bring insights to the development of this technology that a laboratory researcher alone might not have had. Young academic surgeons interested in this field might be well served to be active not only in laboratory research but also in clinical practice. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Impact of the telephone assistive device (TAD) on stuttering severity while speaking on the telephone.

    Science.gov (United States)

    Chambers, Nola

    2009-01-01

    There is extensive experimental evidence that altered auditory feedback (AAF) can have a clinically significant effect on the severity of speech symptoms in people who stutter. However, there is less evidence regarding whether these experimental effects can be observed in naturalistic everyday settings particularly when using the telephone. This study aimed to investigate the effectiveness of the Telephone Assistive Device (TAD), which is designed to provide AAF on the telephone to people who stutter, on reducing stuttering severity. Nine adults participated in a quasi-experimental study. Stuttering severity was measured first without and then with the device in participants' naturalistic settings while making and receiving telephone calls (immediate benefit). Participants were then allowed a week of repeated use of the device following which all measurements were repeated (delayed benefit). Overall, results revealed significant immediate benefits from the TAD in all call conditions. Delayed benefits in received and total calls were also significant. There was substantial individual variability in response to the TAD but none of the demographic or speech-related factors measured in the study were found to significantly impact the benefit (immediate or delayed) derived from the TAD. Results have implications for clinical decision making for adults who stutter.

  10. General and acute care surgical procedures in patients with left ventricular assist devices.

    Science.gov (United States)

    Arnaoutakis, George J; Bittle, Gregory J; Allen, Jeremiah G; Weiss, Eric S; Alejo, Jennifer; Baumgartner, William A; Shah, Ashish S; Wolfgang, Christopher L; Efron, David T; Conte, John V

    2014-04-01

    Left ventricular assist devices (LVADs) have become common as a bridge to heart transplant as well as destination therapy. Acute care surgical (ACS) problems in this population are prevalent but remain ill-defined. Therefore, we reviewed our experience with ACS interventions in LVAD patients. A total of 173 patients who received HeartMate(®) XVE or HeartMate(®) II (HMII) LVADs between December 2001 and March 2010 were studied. Patient demographics, presentation of ACS problem, operative intervention, co-morbidities, transplantation, complications, and survival were analyzed. A total of 47 (27 %) patients underwent 67 ACS procedures at a median of 38 days after device implant (interquartile range 15-110), with a peri-operative mortality rate of 5 % (N = 3). Demographics, device type, and acuity were comparable between the ACS and non-ACS groups. A total of 21 ACS procedures were performed emergently, eight were urgent, and 38 were elective. Of 29 urgent and emergent procedures, 28 were for abdominal pathology. In eight patients, the cause of the ACS problem was related to LVADs or anticoagulation. Cumulative survival estimates revealed no survival differences if patients underwent ACS procedures (p = 0.17). Among HMII patients, transplantation rates were unaffected by an ACS intervention (p = 0.2). ACS problems occur frequently in LVAD patients and are not associated with adverse outcomes in HMII patients. The acute care surgeon is an integral member of a comprehensive approach to effective LVAD management.

  11. Carotid Artery Stenting in a Patient With a Continuous-Flow Left Ventricular Assist Device.

    Science.gov (United States)

    Piazza, Michele; Squizzato, Francesco; Grego, Franco; Bottio, Tommaso; Gerosa, Gino; Antonello, Michele

    2016-08-01

    To demonstrate the safety and feasibility of carotid artery stenting (CAS) in a patient with a continuous-flow left ventricular assist device (LVAD). A 54-year-old woman with a LVAD was referred for a 90% stenosis of the right internal carotid artery (ICA). The patient was offered CAS, and oral anticoagulant was not discontinued in the periprocedural period. Because of absent arterial pulses, percutaneous transfemoral access was obtained under ultrasound guidance. Particular attention was paid to cannulation of the innominate artery; a 7-F guiding catheter was advanced from the descending aorta into the innominate artery under road-mapping, avoiding maneuvers in the ascending aorta where the outflow Dacron graft of the LVAD was anastomosed. To avoid cerebral flow modifications, the Angioguard RX was used as the cerebral protection device rather than other devices such as the flow reversal or flow-clamping systems. At this point, CAS was performed in a standard fashion using the 7×30-mm Precise ProRX stent. The computed tomography angiogram at 6 months showed patency of the stented right ICA. With adequate planning, CAS appears feasible in patients with a LVAD. © The Author(s) 2016.

  12. Use of Ventricular Assist Device in Univentricular Physiology: The Role of Lumped Parameter Models.

    Science.gov (United States)

    Di Molfetta, Arianna; Ferrari, Gianfranco; Filippelli, Sergio; Fresiello, Libera; Iacobelli, Roberta; Gagliardi, Maria G; Amodeo, Antonio

    2016-05-01

    Failing single-ventricle (SV) patients might benefit from ventricular assist devices (VADs) as a bridge to heart transplantation. Considering the complex physiopathology of SV patients and the lack of established experience, the aim of this work was to realize and test a lumped parameter model of the cardiovascular system, able to simulate SV hemodynamics and VAD implantation effects. Data of 30 SV patients (10 Norwood, 10 Glenn, and 10 Fontan) were retrospectively collected and used to simulate patients' baseline. Then, the effects of VAD implantation were simulated. Additionally, both the effects of ventricular assistance and cavopulmonary assistance were simulated in different pathologic conditions on Fontan patients, including systolic dysfunction, diastolic dysfunction, and pulmonary vascular resistance increment. The model can reproduce patients' baseline well. Simulation results suggest that the implantation of VAD: (i) increases the cardiac output (CO) in all the three palliation conditions (Norwood 77.2%, Glenn 38.6%, and Fontan 17.2%); (ii) decreases the SV external work (SVEW) (Norwood 55%, Glenn 35.6%, and Fontan 41%); (iii) increases the mean pulmonary arterial pressure (Pap) (Norwood 39.7%, Glenn 12.1%, and Fontan 3%). In Fontan circulation, with systolic dysfunction, the left VAD (LVAD) increases CO (35%), while the right VAD (RVAD) determines a decrement of inferior vena cava pressure (Pvci) (39%) with 34% increment of CO. With diastolic dysfunction, the LVAD increases CO (42%) and the RVAD decreases the Pvci. With pulmonary vascular resistance increment, the RVAD allows the highest CO (50%) increment with the highest decrement of Pvci (53%). The single ventricular external work (SVEW) increases (decreases) increasing the VAD speed in cavopulmonary (ventricular) assistance. Numeric models could be helpful in this challenging and innovative field to support patients and VAD selection to optimize the clinical outcome and personalize the therapy

  13. Anesthesia for gastrointestinal endoscopy in patients with left ventricular assist devices: Initial experience with 68 procedures

    Directory of Open Access Journals (Sweden)

    Basavana G Goudra

    2013-01-01

    Full Text Available Aims and Objectives: Continuous flow left ventricular assist devices (LVAD have emerged as a reliable treatment option for heart failure. Because of bleeding secondary to anticoagulation, these patients present frequently for gastrointestinal (GI endoscopy. The presently available literature on perioperative management of these patients is extremely limited and is primarily based upon theoretical principles. Materials and Methods: Perioperative records of patients with LVAD undergoing (GI endoscopy between 2008 and 2012 were reviewed. Patient, device and procedure specific information was analyzed. Results: A total of 105 LVADs were implanted, and 68 procedures were performed in 39 patients. The most common indication was GI bleed (48/68, with yearly risk of 8.57% per patient. A total of 63 procedures were performed under deep sedation, with five procedures requiring general anesthesia. Intra-procedure hypotension was managed by fluids and (or vasopressors/inotropes (phenylephrine, ephedrine or milrinone guided by plethysmographic waveform, non-invasive blood pressure (NIBP and LVADs pulsatility index (for HeartMate II/flow pulsatility (for HeartWare. No patient required invasive monitoring and both NIBP and pulse oximeter could be reliably used for monitoring (and guided management in all patients due to the presence of native heart′s pulsatile output. Conclusion: In the presence of residual heart function, with optimal device settings, non-invasive hemodynamic monitoring can be reliably used in these patients while undergoing GI endoscopy under general anesthesia or monitored anesthesia care. Transient hypotensive episodes respond well to fluids/vasopressors without the need of increasing device speed that can be detrimental.

  14. Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device.

    Science.gov (United States)

    Hamid, Q; Snyder, J; Wang, C; Timmer, M; Hammer, J; Guceri, S; Sun, W

    2011-09-01

    In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 °C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 °C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

  15. Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, Q; Snyder, J; Wang, C; Guceri, S; Sun, W [Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA (United States); Timmer, M; Hammer, J, E-mail: sunwei@drexel.edu [Advanced Technologies and Regenerative Medicine, Somerville, NJ (United States)

    2011-09-15

    In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 deg. C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 deg. C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

  16. Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device

    International Nuclear Information System (INIS)

    Hamid, Q; Snyder, J; Wang, C; Guceri, S; Sun, W; Timmer, M; Hammer, J

    2011-01-01

    In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 deg. C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 deg. C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

  17. 78. Asistencia biventricular de larga duración mediante dispositivo heartware hvad miniaturizado

    Directory of Open Access Journals (Sweden)

    M.T. González López

    2012-04-01

    Conclusiones: Existe una limitada experiencia a nivel mundial con el empleo de asistencia de flujo continuo en el corazón derecho. Sin embargo, este tipo de dispositivo permite una técnica relativamente sencilla de implantación, junto con una mayor autonomía y calidad de vida del paciente que precisa soporte biventricular de larga duración como puente al trasplante.

  18. Pump speed modulations and sub-maximal exercise tolerance in left ventricular assist device recipients

    DEFF Research Database (Denmark)

    Jung, Mette Holme; Houston, Brian; Russell, Stuart D

    2017-01-01

    of the 2 sub-maximal tests was determined by randomization. Both patient and physician were blinded to the sequence. Exercise duration, oxygen consumption (VO2) and rate of perceived exertion (RPE), using the Borg scale (score 6 to 20), were recorded. RESULTS: Nineteen patients (all with a HeartMate II...... ventricular assist device) completed 57 exercise tests. Baseline pump speed was 9,326 ± 378 rpm. At AT, workload was 63 ± 26 W (25 to 115 W) and VO2 was 79 ± 14% of maximum. Exercise duration improved by 106 ± 217 seconds (~13%) in Speedinc compared with Speedbase (837 ± 358 vs 942 ± 359 seconds; p = 0...

  19. Singularity now: using the ventricular assist device as a model for future human-robotic physiology.

    Science.gov (United States)

    Martin, Archer K

    2016-04-01

    In our 21 st century world, human-robotic interactions are far more complicated than Asimov predicted in 1942. The future of human-robotic interactions includes human-robotic machine hybrids with an integrated physiology, working together to achieve an enhanced level of baseline human physiological performance. This achievement can be described as a biological Singularity. I argue that this time of Singularity cannot be met by current biological technologies, and that human-robotic physiology must be integrated for the Singularity to occur. In order to conquer the challenges we face regarding human-robotic physiology, we first need to identify a working model in today's world. Once identified, this model can form the basis for the study, creation, expansion, and optimization of human-robotic hybrid physiology. In this paper, I present and defend the line of argument that currently this kind of model (proposed to be named "IshBot") can best be studied in ventricular assist devices - VAD.

  20. Exercise therapy for an older patient with left ventricular assist device.

    Science.gov (United States)

    Park, Won Hah; Seo, Yong Gon; Sung, Ji Dong

    2014-06-01

    A left ventricular assist device (LVAD) is a mechanical circulation support implanted for patients with end-stage heart failure. It may be used either as a bridge to cardiac transplantation or as a destination therapy. The health of a 75-year-old man with a medical history of systolic heart failure worsened. Therefore, he was recommended to have implanted a LVAD (Thoratec Corp.) as a destination therapy. After the surgery, he was enrolled in patient cardiac rehabilitation for the improvement of dyspnea and exercise capacity. In results, there is an improvement on his exercise capacity and quality of life. For the first time in Korea, we reported a benefit of exercise therapy after being implanted with a LVAD.

  1. Carotid Doppler ultrasound findings in patients with left ventricular assist devices.

    Science.gov (United States)

    Cervini, Patrick; Park, Soon J; Shah, Dipesh K; Penev, Irina E; Lewis, Bradley D

    2010-12-01

    Left ventricular assist devices (LVADs) have been used to treat advanced heart failure refractory to medical management, as bridge therapy to myocardial recovery, as bridge therapy to cardiac transplantation, or as destination therapy for patients with unfavorable transplant candidacy. Neurologic complications are some of the most common and devastating complications in these patients. Preoperative carotid ultrasound is, therefore, a standard evaluation in patients at risk for cerebrovascular disease. Postoperative carotid artery Doppler sonography is performed in those patients with neurologic symptoms. It is likely, therefore, that sonographers, radiologists, and other physicians working in a center where LVADs are implanted will likely encounter a carotid artery Doppler study in this patient group. To our knowledge, the carotid Doppler findings in these patients have never been published. We review the Doppler ultrasound findings in 6 patients after LVAD insertion.

  2. Multidrug Resistant Pseudomonas Mycotic Pseudoaneurysm following Cardiac Transplant Bridged by Ventricular Assistant Device

    Directory of Open Access Journals (Sweden)

    C. Aye

    2017-01-01

    Full Text Available Mycotic pseudoaneurysm of aorta following cardiac surgery is rare but is highly fatal if it is unrecognized and untreated. Here, we report a case of a 45-year-old male patient who presented with rapidly progressive multiple pseudoaneurysms of the ascending aorta infected with multidrug resistant (MDR Pseudomonas aeruginosa at 5 weeks after cardiac transplantation, on a background of prior bridging therapy with left ventricular assistant device (LVAD. The patient was successfully treated with the newer cephalosporin, Ceftolozane/Tazobactam, in combination with surgery. This is the first reported case of mycotic pseudoaneurysm infected with MDR Pseudomonas. This case also highlights the importance of high vigilance and timely multimodality treatment in the diagnosis and management of mycotic pseudoaneurysm following cardiac transplant, especially in patients who had LVAD.

  3. Development of ventricular assist devices in China: present status, opportunities and challenges.

    Science.gov (United States)

    Gu, Kaiyun; Chang, Yu; Gao, Bin; Wan, Feng; Loisance, Daniel; Zeng, Yi

    2014-08-01

    The growing number of heart failure patients and the scarcity of organ donors account for the huge need for the development of mechanical circulatory systems, including ventricular assist devices (VADs) and artificial hearts, in China. Several research programmes on blood pumps have been under way for the last three decades. However, unlike in other countries, the development of VADs has been extremely slow, and no system is currently approved and available for clinical application. There are many reasons for this situation. This article provides an overview of the present development of experimental and clinical research on VADs in China. In addition, the challenges for the clinical development of mechanical circulatory support in China are discussed. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  4. Computational fluid dynamics analysis of a maglev centrifugal left ventricular assist device.

    Science.gov (United States)

    Burgreen, Greg W; Loree, Howard M; Bourque, Kevin; Dague, Charles; Poirier, Victor L; Farrar, David; Hampton, Edward; Wu, Z Jon; Gempp, Thomas M; Schöb, Reto

    2004-10-01

    The fluid dynamics of the Thoratec HeartMate III (Thoratec Corp., Pleasanton, CA, U.S.A.) left ventricular assist device are analyzed over a range of physiological operating conditions. The HeartMate III is a centrifugal flow pump with a magnetically suspended rotor. The complete pump was analyzed using computational fluid dynamics (CFD) analysis and experimental particle imaging flow visualization (PIFV). A comparison of CFD predictions to experimental imaging shows good agreement. Both CFD and experimental PIFV confirmed well-behaved flow fields in the main components of the HeartMate III pump: inlet, volute, and outlet. The HeartMate III is shown to exhibit clean flow features and good surface washing across its entire operating range.

  5. A phone-assistive device based on Bluetooth technology for cochlear implant users.

    Science.gov (United States)

    Qian, Haifeng; Loizou, Philipos C; Dorman, Michael F

    2003-09-01

    Hearing-impaired people, and particularly hearing-aid and cochlear-implant users, often have difficulty communicating over the telephone. The intelligibility of telephone speech is considerably lower than the intelligibility of face-to-face speech. This is partly because of lack of visual cues, limited telephone bandwidth, and background noise. In addition, cellphones may cause interference with the hearing aid or cochlear implant. To address these problems that hearing-impaired people experience with telephones, this paper proposes a wireless phone adapter that can be used to route the audio signal directly to the hearing aid or cochlear implant processor. This adapter is based on Bluetooth technology. The favorable features of this new wireless technology make the adapter superior to traditional assistive listening devices. A hardware prototype was built and software programs were written to implement the headset profile in the Bluetooth specification. Three cochlear implant users were tested with the proposed phone-adapter and reported good speech quality.

  6. Reduced Anxiety and Depression in Patients With Advanced Heart Failure After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Yost, Gardner; Bhat, Geetha; Mahoney, Edward; Tatooles, Antone

    Despite the high prevalence of depression and anxiety in patients with advanced heart failure, the effects of left ventricular assist device (LVAD) implantation on these critically important aspects of mental health are not well understood. We sought to assess changes in depression and anxiety following LVAD implantation. The Beck Depression Inventory-II (BDI-II) and Beck Anxiety Inventory (BAI) were administered to 54 patients by a clinical psychologist at a mean of 12 days before LVAD implantation and 251 days after implantation. Patient demographics and clinical data were collected concurrently to psychologic testing. Changes in BDI-II, BAI, and clinical markers of heart failure were assessed using paired t-tests. A p Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

  7. Using Technology in Social Work Practice: The mDad (Mobile Device Assisted Dad Case Study

    Directory of Open Access Journals (Sweden)

    Shawna J. Lee

    2015-07-01

    Full Text Available Mobile technology presents an exciting opportunity for social workers to reach populations that are typically underserved by interventions and services. We present one application of technology that is particularly relevant to social work practice. The mDad (Mobile Device Assisted Dad app was developed to augment existing social work practices by providing a father-friendly tool to help new fathers learn about and engage with their infants and toddlers. We discuss the process of developing the app content and conducting usability testing of the mDad app. We conclude with a discussion of the lessons learned from the mDad project, and the challenges of implementation and dissemination of technology-based interventions in community contexts.

  8. A MOBILE-DEVICE-SUPPORTED PEER-ASSISTED LEARNING SYSTEM FOR COLLABORATIVE EARLY EFL READING

    Directory of Open Access Journals (Sweden)

    Yu-Ju Lan

    2007-02-01

    Full Text Available Collaborative learning methods which emphasize peer interaction have been widely applied to increase the intensity and effectiveness of EFL reading programs. However, simply grouping students heterogeneously and assigning them group goals does not guarantee that effective collaborative learning will ensue. The present research includes two studies. In Study One, the weaknesses of collaborative learning in a traditional EFL setting were observed. Then, in Study Two, a mobile-device-supported peer-assisted learning (MPAL system was developed for the purpose of addressing the identified weaknesses. Two classes of twenty-six third grade students participated in the present research to examine the unique contribution of MPAL to collaborative EFL reading activities. The collaborative behavior of elementary EFL learners was videotaped and analyzed. Detailed analysis of the videotaped behavior indicated that MPAL helped improve collaboration in elementary school level EFL learners and promotes their reading motivation.

  9. Exercise physiology, testing, and training in patients supported by a left ventricular assist device.

    Science.gov (United States)

    Loyaga-Rendon, Renzo Y; Plaisance, Eric P; Arena, Ross; Shah, Keyur

    2015-08-01

    The left ventricular assist device (LVAD) is an accepted treatment alternative for the management of end-stage heart failure. As we move toward implantation of LVADs in less severe cases of HF, scrutiny of functional capacity and quality of life becomes more important. Patients demonstrate improvements in exercise capacity after LVAD implantation, but the effect is less than predicted. Exercise training produces multiple beneficial effects in heart failure patients, which would be expected to improve quality of life. In this review, we describe factors that are thought to participate in the persistent exercise impairment in LVAD-supported patients, summarize current knowledge about the effect of exercise training in LVAD-supported patients, and suggest areas for future research. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  10. Continuous flow left ventricular assist devices: shared care goals of monitoring and treating patients.

    Science.gov (United States)

    Estep, Jerry D; Trachtenberg, Barry H; Loza, Laurie P; Bruckner, Brian A

    2015-01-01

    Continuous-flow left ventricular assist devices (CF-LVADs) have been clinically adopted as a long-term standard of care therapy option for patients with end-stage heart failure. For many patients, shared care between the care providers at the implanting center and care providers in the community in which the patient resides is a clinical necessity. The aims of this review are to (1) provide a rationale for the outpatient follow-up exam and surveillance testing used at our center to monitor patients supported by the HeartMate II(®) CF-LVAD (Thoratec Corporation, Pleasanton, CA) and (2) provide the protocol/algorithms we use for blood pressure, driveline exit site, LVAD alarm history, surveillance blood work, and echocardiography monitoring in this patient population. In addition, we define our partnership outpatient follow-up protocol and the "shared care" specific responsibilities we use with referring health care providers to best manage many of our patients.

  11. Outcomes of ventricular assist device implantation in children and young adults: the Melbourne experience.

    Science.gov (United States)

    Shi, William Y; Marasco, Silvana F; Saxena, Pankaj; d'Udekem, Yves; Yong, Matthew S; Mitnovetski, Sergei; Brizard, Christian P; McGiffin, David C; Weintraub, Robert G; Konstantinov, Igor E

    2016-12-01

    We evaluated our experience with ventricular assist device (VAD) implantation in children and young adults. A total of 64 patients underwent VAD implantation in two centres. The mean age was 15 ± 7.2 years. Thirty-five (55%) patients were under 18 years of age. Devices implanted included the Thoratec Paracorporeal in 30 (47%) patients, Berlin Heart EXCOR in 11 (17%) and VentrAssist in 14 (22%). The diagnosis was cardiomyopathy in 53, congenital heart disease in 11, and graft failure in four patients. There were 10 (16%) in-hospital deaths. Mortality was higher in patients <18 years of age (26% compared with 3.4% for those ≥18 years, P = 0.02). The use of extracorporeal membrane oxygenation prior to VAD implantation was associated with higher mortality (P = 0.006). Seventeen (27%) patients experienced stroke. Nine patients (14%) required change of VAD because of thrombosis. Transplantation was performed in 44 patients after a mean of 131 ± 141 days on VAD, 11 patients died without transplantation and three patients currently await transplantation. The VAD was explanted in six patients because of recovery. Overall survival from VAD implantation was 69% and 61% at 5 and 10 years, respectively. The 5-year post-transplant survival for those bridged with VAD support was 91% and was comparable with a cohort of patients who did not receive a pre-transplant VAD. Children requiring pre-transplant VAD support have a higher mortality and morbidity compared with young adults. Survival after heart transplantation those supported with VADs was similar to patients of similar age who did not require pre-transplant support. © 2015 Royal Australasian College of Surgeons.

  12. Falls and Use of Assistive Devices in Stroke Patients with Hemiparesis: Association with Balance Ability and Fall Efficacy.

    Science.gov (United States)

    Kim, Oksoo; Kim, Jung-Hee

    2015-01-01

    This study investigates balance ability and the fall efficacy with regard to the experiences of stroke patients with hemiparesis. The experience of falling, the use of assistive devices, and each disease-related characteristic were assessed using face-to-face interviews and a self-reported questionnaire. The Berg Balance Scale and Fall Efficacy Scale were used to measure balance ability and confidence. The fall efficacy was significantly lower in participants who had experienced falls than those who had not. The participants who used assistive devices exhibited low balance ability and fall efficacy compared to those who did not use assistive devices. Stroke patients with fall experience and walking aids might be considered at increased risk of falling. Preventive measures for individuals using walking aids may be beneficial in reducing the fall rate of community-dwelling stroke patients. © 2014 Association of Rehabilitation Nurses.

  13. Sequential biventricular pacing improves regional contractility, longitudinal function and dyssynchrony in patients with heart failure and prolonged QRS

    Directory of Open Access Journals (Sweden)

    Ring Margareta

    2010-04-01

    Full Text Available Abstract Aims Biventricular pacing (BiP is an effective treatment in systolic heart failure (HF patients with prolonged QRS. However, approximately 35% of the patients receiving BiP are classified as non-responders. The aim of this study is to evaluate the acute effects of VV-optimization on systolic heart function. Methods Twenty-one HF patients aged 72 (46-88 years, QRS 154 (120-190 ms, were studied with echocardiography, Tissue Doppler Imaging (TDI and 3D-echo the first day after receiving a BiP device. TDI was performed; during simultaneous pacing (LV-lead pacing 4 ms before the RV-lead and during sequential pacing (LV 20 and 40 ms before RV and RV 20 and 40 ms before LV-lead pacing. Systolic heart function was studied by tissue tracking (TT for longitudinal function and systolic maximal velocity (SMV for regional contractility and signs of dyssynchrony assessed by time-delays standard deviation of aortic valve opening to SMV, AVO-SMV/SD and tissue synchronization imaging (TSI. Results The TT mean value preoperatively was 4,2 ± 1,5 and increased at simultaneous pacing to 5,0 ± 1,2 mm (p Conclusions VV-optimization in the acute phase improves systolic heart function more than simultaneous BiP pacing. Long-term effects should be evaluated in prospective randomized trials.

  14. Handcrafted Vacuum-Assisted Device for Skin Ulcers Treatment Versus Traditional Therapy, Randomized Controlled Trial.

    Science.gov (United States)

    Gonzalez, Israel Gonzalez; Angel, Medina Andrade Luis; Baez, Maria Valeria Jimenez; Ruiz Flores, Brenda; de Los Angeles Martinez Ferretiz, Maria; Woolf, Stephanny Vanestty; López, Israel; Sandoval-Jurado, Luis; Pat-Espadas, Fany Guadalupe; Cruz, Alan Alejandro Reyes; Delgado, Arsenio Torres

    2017-02-01

    Chronic lower limb ulcers constitute a public health problem, with important socioeconomic implications and high attention cost. This trial evaluates handcrafted vacuum-assisted therapy versus traditional treatment effectiveness for lower limbs ulcers. It was a prospective randomized clinical trial conducted over 144 patients with lower limbs ulcers. Patients were randomized into two groups of 72 patients: Experimental group were treated with debridement, cure and a handcrafted vacuum-assisted device that was changed every 72 h. Control group was treated with debridement and cure with soap every 24 h. Ulcers were evaluated every 72 h and on 10th day. The presence of systemic inflammatory response, pain, granulation tissue and viability for discharge was registered and analyzed . After exclusion of 18 patients, 126 were included, 65.1% were men with an average of 58 years. Sole region ulcer by diabetic foot was the more frequent in both groups (73%). Leukocytes count, systemic inflammatory response and pain were significantly lower in experimental group (p ulcers. This system would benefit patients favoring earlier infection control, faster granulation tissue appearance and earlier discharge. Clinical trials registered in https://www.clinicaltrials.gov/ Number NCT02512159.

  15. Performance of Noninvasive Assessment in the Diagnosis of Right Heart Failure After Left Ventricular Assist Device.

    Science.gov (United States)

    Joly, Joanna M; El-Dabh, Ashraf; Marshell, Ramey; Chatterjee, Arka; Smith, Michelle G; Tresler, Margaret; Kirklin, James K; Acharya, Deepak; Rajapreyar, Indranee N; Tallaj, José A; Pamboukian, Salpy V

    2018-06-01

    Right heart failure (RHF) after left ventricular assist device (LVAD) is associated with poor outcomes. Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) defines RHF as elevated right atrial pressure (RAP) plus venous congestion. The purpose of this study was to examine the diagnostic performance of the noninvasive INTERMACS criteria using RAP as the gold standard. We analyzed 108 patients with LVAD who underwent 341 right heart catheterizations (RHC) between January 1, 2006, and December 31, 2013. Physical exam, echocardiography, and laboratory data at the time of RHC were collected. Conventional two-by-two tables were used and missing data were excluded. The noninvasive INTERMACS definition of RHF is 32% sensitive (95% CI, 0.21-0.44) and 97% specific (95% CI, 0.95-0.99) for identifying elevated RAP. Clinical assessment failed to identify two-thirds of LVAD patients with RAP > 16 mm Hg. More than half of patients with elevated RAP did not have venous congestion, which may represent a physiologic opportunity to mitigate the progression of disease before end-organ damage occurs. One-quarter of patients who met the noninvasive definition of RHF did not actually have elevated RAP, potentially exposing patients to unnecessary therapies. In practice, if any component of the INTERMACS definition is present or equivocal, our data suggest RHC is warranted to establish the diagnosis.

  16. The pharmacotherapy implications of ventricular assist device in the patient with end-stage heart failure.

    Science.gov (United States)

    Von Ruden, Serena A S; Murray, Margaret A; Grice, Jennifer L; Proebstle, Amy K; Kopacek, Karen J

    2012-04-01

    Advances in mechanical circulatory support, such as the use of ventricular assist devices (VADs), have become a means for prolonging survival in end-stage heart failure (HF). VADs decrease the symptoms of HF and improve quality of life by replacing some of the work of a failing heart. They unload the ventricle to provide improved cardiac output and end-organ perfusion, resulting in improvement in cardiorenal syndromes and New York Heart Association functional class rating. VADs are currently used asa bridge to heart transplantation, a bridge to recovery of cardiac function, or as destination therapy. Complications of VAD include bleeding, infections, arrhythmias, multiple organ failure, right ventricular failure, and neurological dysfunction. Patients with VAD have unique pharmacotherapeutic requirements in terms of anticoagulation, appropriate antibiotic selection, and continuation of HF medications. Pharmacists in acute care and community settings are well prepared to care for the patient with VAD. These patients require thorough counseling and follow-up with regard to prevention and treatment of infections, appropriate levels of anticoagulation, and maintenance of fluid balance. A basic understanding of this unique therapy can assist pharmacists in attending to the needs of patients with VAD.

  17. Wave Intensity Analysis of Right Ventricular Function during Pulsed Operation of Rotary Left Ventricular Assist Devices.

    Science.gov (United States)

    Bouwmeester, J Christopher; Park, Jiheum; Valdovinos, John; Bonde, Pramod

    2018-05-29

    Changing the speed of left ventricular assist devices (LVADs) cyclically may be useful to restore aortic pulsatility; however, the effects of this pulsation on right ventricular (RV) function are unknown. This study investigates the effects of direct ventricular interaction by quantifying the amount of wave energy created by RV contraction when axial and centrifugal LVADs are used to assist the left ventricle. In 4 anesthetized pigs, pressure and flow were measured in the main pulmonary artery and wave intensity analysis was used to identify and quantify the energy of waves created by the RV. The axial pump depressed the intensity of waves created by RV contraction compared with the centrifugal pump. In both pump designs, there were only minor and variable differences between the continuous and pulsed operation on RV function. The axial pump causes the RV to contract with less energy compared with a centrifugal design. Diminishing the ability of the RV to produce less energy translates to less pressure and flow produced, which may lead to LVAD-induced RV failure. The effects of pulsed LVAD operation on the RV appear to be minimal during acute observation of healthy hearts. Further study is necessary to uncover the effects of other modes of speed modulation with healthy and unhealthy hearts to determine if pulsed operation will benefit patients by reducing LVAD complications.

  18. Tooling device design for vibration-assisted high speed shaping of PMMA

    International Nuclear Information System (INIS)

    Mostofa, Md. Golam; Noh, J. H.; Kim, H. Y.; Ahn, J. H.; Kang, D. B.

    2010-01-01

    PMMA optical components that are used as one of the most important parts of high precision equipment and machines are increasingly replacing the glass due to the various advantages of PMMA. Especially in Light Guide Panels, the PMMA sheet that is used in Liquid Crystal Displays plays an important role in scattering the incident light and requires very fine machining as the sheet is directly related to the optical characteristics of the panels. The High Speed End milling and High Speed Shaping processes that are widely adopted and applied to the precise machining of Light Incident Plane still have quality problems, such as cracks, breakages, poor waviness, and straightness. This paper presents the tooling device design for machining a Light Incident Plane through vibration-assisted High Speed Shaping for increasing the optical quality by minimizing the above-mentioned problems. The cutting tool and the tool post presented in this paper are designed by the authors to increase the magnitude of the cutting stroke by adopting the resonant frequency without weakening the stiffness and to reduce vibrations during even high speed feeding. The dynamic characteristics of the cutting tool and the tool post are evaluated through simulation and experiment as well. The results reveal very appropriate dynamic characteristics for vibration-assisted High Speed Shaping

  19. The influence of assistive technology devices on the performance of activities by visually impaired

    Directory of Open Access Journals (Sweden)

    Suzana Rabello

    2014-04-01

    Full Text Available Objective: To establish the influence of assistive technology devices (ATDs on the performance of activities by visually impaired schoolchildren in the resource room. Methods: A qualitative study that comprised observation and an educational intervention in the resource room. The study population comprised six visually impaired schoolchildren aged 12 to 14 years old. The participants were subjected to an eye examination, prescribed ATDs comprising optical and non-optical devices, and provided an orientation on the use of computers. The participants were assessed based on eye/object distance, font size, and time to read a computer screen and printed text. Results: The ophthalmological conditions included corneal opacity, retinochoroiditis, retinopathy of prematurity, aniridia, and congenital cataracts. Far visual acuity varied from 20/200 to 20/800 and near visual acuity from 0.8 to 6 M. Telescopes, spherical lenses, and support magnifying glasses were prescribed. Three out of five participants with low vision after intervention could decrease the font size on the screen computer, and most participants (83.3% reduced their reading time at the second observation session. Relative to the printed text, all the participants with low vision were able to read text written in smaller font sizes and reduced their reading time at the second observation session. Conclusion: Reading skills improved after the use of ATDs, which allowed the participants to perform their school tasks equally to their classmates.

  20. Practical approaches to commencing device-assisted therapies for Parkinson disease in Australia.

    Science.gov (United States)

    Williams, David R; Evans, Andrew H; Fung, Victor S C; Hayes, Michael; Iansek, Robert; Kimber, Thomas; O'Sullivan, John D; Sue, Carolyn M

    2017-10-01

    In Australia 1% of individuals aged over 50 years have Parkinson disease (PD). Guidance for commencing device-assisted therapies (DAT) for PD in Australia was developed based on a review of European recommendations and their relevance to the local clinical setting. An online survey and teleconference discussions were held by a group of eight local movement disorder experts to develop consensus. Referral to a movement disorder specialist and consideration of DAT is appropriate when motor fluctuations cause disability or reduced quality of life, response to treatment is inconsistent or motor fluctuations and dyskinesias require frequent treatment adjustment without apparent benefit and levodopa is required four or more times daily. Three types of DAT are available in Australia for patients with PD: continuous subcutaneous apomorphine; continuous levodopa-carbidopa intestinal gel infusion; and deep brain stimulation. All improve consistency of motor response. The most important aspects when considering which DAT to use are the preferences of the patient and their carers, patient comorbidities, age, cognitive function and neuropsychiatric status. Patients and their families need to be provided with treatment options that are suitable to them, with adequate explanations regarding the recommendations and comparison of potential device-related complications. DAT are best managed, where possible, in a specialist centre with experience in all three types of therapy. Proactive and early management of symptoms during disease progression is essential to maintain optimally motor responses and quality of life in patients with PD. © 2017 Royal Australasian College of Physicians.

  1. Left ventricular assist device: exercise capacity evolution and rehabilitation added value.

    Science.gov (United States)

    Lamotte, Michel X; Chimenti, Sara; Deboeck, Gael; Gillet, Alexis; Kacelenenbogen, Raymond; Strapart, Jonathan; Vandeneynde, Frédéric; Van Nooten, Guido; Antoine, Martine

    2018-06-01

    With more than 15,000 implanted patients worldwide and a survival rate of 80% at 1-year and 59% at 5-years, left ventricular assist device (LVAD) implantation has become an interesting strategy in the management of heart failure patients who are resistant to other kinds of treatment. There are limited data in the literature on the change over time of exercise capacity in LVAD patients, as well as limited knowledge about the beneficial effects that rehabilitation might have on these patients. Therefore, the aim of our study was to evaluate the evolution of exercise capacity on a cohort of patients implanted with the same device (HeartWare © ) and to analyse the potential impact of rehabilitation. Sixty-two patients implanted with a LVAD between June 2011 and June 2015 were screened. Exercise capacity was evaluated by cardiopulmonary exercise testing at 6 weeks, 6 and 12 months after implantation. We have observed significant differences in the exercise capacity and evolution between the trained and non-trained patients. Some of the trained patients nearly normalised their exercise capacity at the end of the rehabilitation programme. Exercise capacity of patient implanted with a HeartWare © LVAD increased in the early period after implantation. Rehabilitation allowed implanted patients to have a significantly better evolution compared to non-rehabilitated patients.

  2. Successful Implantation of a Left Ventricular Assist Device After Treatment With the Paracor HeartNet.

    Science.gov (United States)

    Schweiger, Martin; Stepanenko, Alexander; Potapov, Evgenji; Drews, Thorsten; Hetzer, Roland; Krabatsch, Thomas

    2010-01-01

    The Paracor HeartNet, a ventricular constraint device for the treatment of heart failure (HF), is implanted through a left lateral thoracotomy. It envelopes the heart like a mesh "bag." This method of application raises the question of whether adhesions with the pericardium allow the safe implantation of a left ventricular assist device (LVAD) if HF worsens. A male patient who had undergone implantation of the Paracor HeartNet 42 months earlier presented with advanced HF for cardiac transplantation. The patient's condition deteriorated, and because no suitable organ for transplantation was available, implantation of an LVAD became necessary. Surgery was performed via a median sternotomy without complications. No severe adhesions were found. This is the first report on "how to do" LVAD implantation after Paracor HeartNet implantation with images and information about cutting the constraint. Because the Paracor HeartNet is "wrapped" around the heart, concerns persist that severe adhesions with the pericardium might occur. In this case, LVAD implantation after therapy with the Paracor HeartNet was without complications, and the expected massive adhesions were absent.

  3. Non-Invasive Mapping of Intraventricular Flow Patterns in Patients Treated with Left Ventricular Assist Devices

    Science.gov (United States)

    Miramontes, Marissa; Rossini, Lorenzo; Braun, Oscar; Brambatti, Michela; Almeida, Shone; Mizeracki, Adam; Martinez-Legazpi, Pablo; Benito, Yolanda; Bermejo, Javier; Kahn, Andrew; Adler, Eric; Del Álamo, Juan C.

    2017-11-01

    In heart failure patients, left ventricular (LV) assist devices (LVADs) decrease mortality and improve quality of life. We hypothesize echo color Doppler velocimetry (echo-CDV), an echocardiographic flow mapping modality, can non-invasively characterize the effect of LVAD support, optimize the device, thereby decreasing the stoke rate present in these patients. We used echo-CDV to image LV flow at baseline LVAD speed and during a ramp test in LVAD patients (Heartmate II, N =10). We tracked diastolic vortices and mapped blood stasis and cumulative shear. Compared to dilated cardiomyopathy (DCM) patients without LVADs, the flow had a less prominent diastolic vortex ring, and transited directly from mitral valve to cannula. Residence time and shear were significantly lower compared to healthy controls and DCMs. Aortic regurgitation and a large LV vortex presence or a direct mitral jet towards the cannula affected blood stasis region location and size. Flow patterns, residence time and shear depended on LV geometry, valve function and LVAD speed in a patient specific manner. This new methodology could be used with standard echo, hemodynamics and clinical information to find the flow optimizing LAVD setting minimizing stasis for each patient.

  4. Diffractive optical devices produced by light-assisted trapping of nanoparticles.

    Science.gov (United States)

    Muñoz-Martínez, J F; Jubera, M; Matarrubia, J; García-Cabañes, A; Agulló-López, F; Carrascosa, M

    2016-01-15

    One- and two-dimensional diffractive optical devices have been fabricated by light-assisted trapping and patterning of nanoparticles. The method is based on the dielectrophoretic forces appearing in the vicinity of a photovoltaic crystal, such as Fe:LiNbO3, during or after illumination. By illumination with the appropriate light distribution, the nanoparticles are organized along patterns designed at will. One- and two-dimensional diffractive components have been achieved on X- and Z-cut Fe:LiNbO3 crystals, with their polar axes parallel and perpendicular to the crystal surface, respectively. Diffraction gratings with periods down to around a few micrometers have been produced using metal (Al, Ag) nanoparticles with radii in the range of 70-100 nm. Moreover, several 2D devices, such as Fresnel zone plates, have been also produced showing the potential of the method. The diffractive particle patterns remain stable when light is removed. A method to transfer the diffractive patterns to other nonphotovoltaic substrates, such as silica glass, has been also reported.

  5. Development of a fixation device for robot assisted fracture reduction of femoral shaft fractures: a biomechanical study.

    Science.gov (United States)

    Weber-Spickschen, T S; Oszwald, M; Westphal, R; Krettek, C; Wahl, F; Gosling, T

    2010-01-01

    Robot assisted fracture reduction of femoral shaft fractures provides precise alignment while reducing the amount of intraoperative imaging. The connection between the robot and the fracture fragment should allow conventional intramedullary nailing, be minimally invasive and provide interim fracture stability. In our study we tested three different reduction tools: a conventional External Fixator, a Reposition-Plate and a Three-Point-Device with two variations (a 40 degrees and a 90 degrees version). We measured relative movements between the tools and the bone fragments in all translation and rotation planes. The Three-Point-Device 90 degrees showed the smallest average relative displacement and was the only device able to withstand the maximum applied load of 70 Nm without failure of any bone fragment. The Three-Point-Device 90 degrees complies with all the stipulated requirements and is a suitable interface for robot assisted fracture reduction of femoral shaft fractures.

  6. Heat Generation in Axial and Centrifugal Flow Left Ventricular Assist Devices.

    Science.gov (United States)

    Yost, Gardner; Joseph, Christine Rachel; Royston, Thomas; Tatooles, Antone; Bhat, Geetha

    Despite increasing use of left ventricular assist devices (LVADs) as a surgical treatment for advanced heart failure in an era of improved outcomes with LVAD support, the mechanical interactions between these pumps and the cardiovascular system are not completely understood. We utilized an in vitro mock circulatory loop to analyze the heat production incurred by operation of an axial flow and centrifugal flow LVAD. A HeartMate II and a HeartWare HVAD were connected to an abbreviated flow loop and were implanted in a viscoelastic gel. Temperature was measured at the surface of each LVAD. Device speed and fluid viscosity were altered and, in the HeartMate II, as artificial thrombi were attached to the inflow stator, impeller, and outflow stator. The surface temperatures of both LVADs increased in all trials and reached a plateau within 80 minutes of flow initiation. Rate of heat generation and maximum system temperature were greater when speed was increased, when viscosity was increased, and when artificial thrombi were attached to the HeartMate II impeller. Normal operation of these two widely utilized LVADs results in appreciable heat generation in vitro. Increased pump loading resulted in more rapid heat generation, which was particularly severe when a large thrombus was attached to the impeller of the HeartMate II. While heat accumulation in vivo is likely minimized by greater dissipation in the blood and soft tissues, focal temperature gains with the pump housing of these two devices during long-term operation may have negative hematological consequences.

  7. Late outcomes of subcostal exchange of the HeartMate II left ventricular assist device: a word of caution.

    Science.gov (United States)

    Yu, Sarah N; Takayama, Hiroo; Han, Jiho; Garan, Arthur R; Kurlansky, Paul; Yuzefpolskaya, Melana; Colombo, Paolo C; Naka, Yoshifumi; Takeda, Koji

    2018-04-10

    Previous studies have shown the usefulness of the subcostal exchange of the HeartMate II left ventricular assist device for device malfunction. However, long-term data are still limited. Between March 2004 and July 2017, 41 of 568 (7.2%) patients who had received a HeartMate II implant at our institution had a device exchange via a subcostal incision. We summarized early and late outcomes. Forty-one patients had a total of 48 subcostal pump exchanges. Indications for device exchange included device thrombosis (n = 31, 76%), driveline infection (n = 2, 5%) and driveline injury (n = 8, 19%). All of the procedures were successful, and there were no in-hospital deaths. A Kaplan-Meier survival curve showed 30-day and 1-year survival rates after subcostal exchange of 100% and 94.6%, respectively. However, 10 (25%) patients had left ventricular assist device-related infections following subcostal exchange that included 7 pump pocket infections and 3 driveline infections. Freedom from left ventricular assist device-related infection at 1 year after subcostal exchange was 79.3%. Thirteen (32%) patients had device malfunction due to pump thrombosis that required a 2nd device exchange. Seven patients had recurrent thrombosis. Three (7%) patients had a stroke. Freedom from device thrombosis and from a stroke event at 1 year was 74.4%. Subcostal pump exchange can be safely performed. However, there is a substantial risk of infection and recurrent thrombosis. Careful follow-up for late complications is mandatory.

  8. Cardiac transplantation after bridged therapy with continuous flow left ventricular assist devices.

    Science.gov (United States)

    Deo, Salil V; Sung, Kiick; Daly, Richard C; Shah, Ishan K; Altarabsheh, Salah E; Stulak, John M; Joyce, Lyle D; Boilson, Barry A; Kushwaha, Sudhir S; Park, Soon J

    2014-03-01

    Cardiac transplantation is an effective surgical therapy for end-stage heart failure. Patients (pts) may need to be bridged with a continuous flow left ventricular assist device (CF-LVAD) while on the transplant list as logistic factors like organ availability are unknown. Cardiac transplantation post-LVAD can be a surgically challenging procedure and outcome in these pts is perceived to be poorer based on experience with earlier generation pulsatile flow pumps. Data from a single institution comparing these pts with those undergoing direct transplantation in the present era of continuous flow device therapy are limited. Evaluate results of cardiac transplantation in pts bridged with a CF-LVAD (BTx) and compare outcomes with pts undergoing direct transplantation (Tx) in a single institution. From June 2007 till January 2012, 106 pts underwent cardiac transplantation. Among these, 37 (35%) pts (51±11 years; 85% male) were bridged with a CF-LVAD (BTx), while 70 (65%) comprised the Tx group (53±12 years; 72% males). The median duration of LVAD support was 227 (153,327) days. During the period of LVAD support, 10/37 (27%) pts were upgraded to status 1A and all were successfully transplanted. Median hospital stay in the BTx (14 days) was slightly longer than the Tx group (12 days) but not statistically significant (p=0.21). In-hospital mortality in the BTx (5%) and Tx (1%) were comparable (p=0.25). Estimated late survival in the BTx cohort was 94±7, 90±10 and 83±16% at the end of one, two and three years, respectively which was comparable to 97±4%, 93±6% and 89±9% for the Tx group (p=0.50). Cardiac transplantation after LVAD implant can be performed with excellent results. Patients can be supported on the left ventricular assist device even for periods close to a year with good outcome after cardiac transplantation. Copyright © 2013 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand

  9. State-of-the-art implantable cardiac assist device therapy for heart failure: bridge to transplant and destination therapy.

    Science.gov (United States)

    Park, S J; Kushwaha, S S; McGregor, C G A

    2012-01-01

    Congestive heart failure is associated with poor quality of life (QoL) and low survival rates. The development of state-of-the-art cardiac devices holds promise for improved therapy in patients with heart failure. The field of implantable cardiac assist devices is changing rapidly with the emergence of continuous-flow pumps (CFPs). The important developments in this field, including pertinent clinical trials, registry reports, innovative research, and potential future directions are discussed in this paper.

  10. Flow Visualization of Three-Dimensionality Inside the 12 cc Penn State Pulsatile Pediatric Ventricular Assist Device

    OpenAIRE

    Roszelle, Breigh N.; Deutsch, Steven; Manning, Keefe B.

    2010-01-01

    In order to aid the ongoing concern of limited organ availability for pediatric heart transplants, Penn State has continued development of a pulsatile Pediatric Ventricular Assist Device (PVAD). Initial studies of the PVAD observed an increase in thrombus formation due to differences in flow field physics when compared to adult sized devices, which included a higher degree of three-dimensionality. This unique flow field brings into question the use of 2D planar particle image velocimetry (PIV...

  11. Loose-Lipped Mobile Device Intelligent Personal Assistants: A Discussion of Information Gleaned from Siri on Locked iOS Devices.

    Science.gov (United States)

    Horsman, Graeme

    2018-04-23

    The forensic analysis of mobile handsets is becoming a more prominent factor in many criminal investigations. Despite such devices frequently storing relevant evidential content to support an investigation, accessing this information is becoming an increasingly difficult task due to enhanced effective security features. Where access to a device's resident data is not possible via traditional mobile forensic methods, in some cases it may still be possible to extract user information via queries made to an installed intelligent personal assistant. This article presents an evaluation of the information which is retrievable from Apple's Siri when interacted with on a locked iOS device running iOS 11.2.5 (the latest at the time of testing). The testing of verbal commands designed to elicit a response from Siri demonstrate the ability to recover call log, SMS, Contacts, Apple Maps, Calendar, and device information which may support any further investigation. © 2018 American Academy of Forensic Sciences.

  12. Surgical treatment of tricuspid valve insufficiency promotes early reverse remodeling in patients with axial-flow left ventricular assist devices.

    Science.gov (United States)

    Maltais, Simon; Topilsky, Yan; Tchantchaleishvili, Vakhtang; McKellar, Stephen H; Durham, Lucian A; Joyce, Lyle D; Daly, Richard C; Park, Soon J

    2012-06-01

    The HeartMate II (Thoratec Corp, Pleasanton, Calif) continuous-flow left ventricular assist device has emerged as the standard of care for patients with advanced heart failure. The objective of this study was to assess the safety and early effectiveness of concomitant tricuspid valve procedures in patients undergoing implantation of a HeartMate II device. From February 2007 to April 2010, 83 patients underwent HeartMate II left ventricular assist device implantation. Of these, 37 patients had concomitant tricuspid valve procedures (32 repairs, 5 replacements) for severe tricuspid regurgitation. The effects of a tricuspid valve procedure on tricuspid regurgitation and right ventricular remodeling were assessed comparing echocardiographic findings at baseline and 30 days after left ventricular assist device implantation. Overall survival was also compared. Patients undergoing a concomitant tricuspid valve procedure had more tricuspid regurgitation (vena contracta, 5.6 ± 2.1 mm vs 2.9 ± 2.0 mm; P tricuspid regurgitation was worse in patients who underwent left ventricular assist device implantation alone (+18.6%), whereas it improved significantly in patients undergoing a concomitant tricuspid valve procedure (-50.2%) (P = .005). A corresponding significant reduction in right ventricular end-diastolic area (33.6% ± 6.2% vs 30.1% ± 9.7%; P = .03) and a trend toward better right ventricular function (55.5% ± 79.7% vs 35.7% ± 60.5%; P = .28) were noted in patients undergoing a concomitant tricuspid valve procedure. Survival was comparable between the 2 groups. In patients with severe tricuspid regurgitation undergoing left ventricular assist device implantation, a concomitant tricuspid valve procedure effectively reduces tricuspid regurgitation and promotes reverse remodeling of the right ventricle. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  13. Left ventricular assist device implantation in a patient who had previously undergone apical myectomy for hypertrophic cardiomyopathy.

    Science.gov (United States)

    Cho, Yang Hyun; Deo, Salil V; Topilsky, Yan; Grogan, Martha A; Park, Soon J

    2012-03-01

    Apical hypertrophy is a rare variant of hypertropic cardiomyopathy. These patients may present with end-stage congestive heart failure subsequent to long standing diastolic dysfunction. We report the technique for left ventricular assist device insertion in a patient with previous apical myectomy for hypertrophic cardiomyopathy. © 2012 Wiley Periodicals, Inc.

  14. Enhancement of arterial pressure pulsatility by controlling continuous-flow left ventricular assist device flow rate in mock circulatory system

    NARCIS (Netherlands)

    Bozkurt, S.; van de Vosse, F.N.; Rutten, M.C.M.

    Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase

  15. Clinical manifestations and management of left ventricular assist device-associated infections.

    Science.gov (United States)

    Nienaber, Juhsien Jodi C; Kusne, Shimon; Riaz, Talha; Walker, Randall C; Baddour, Larry M; Wright, Alan J; Park, Soon J; Vikram, Holenarasipur R; Keating, Michael R; Arabia, Francisco A; Lahr, Brian D; Sohail, M Rizwan

    2013-11-01

    Infection is a serious complication of left ventricular assist device (LVAD) therapy. Published data regarding LVAD-associated infections (LVADIs) are limited by single-center experiences and use of nonstandardized definitions. We retrospectively reviewed 247 patients who underwent continuous-flow LVAD implantation from January 2005 to December 2011 at Mayo Clinic campuses in Minnesota, Arizona, and Florida. LVADIs were defined using the International Society for Heart and Lung Transplantation criteria. We identified 101 episodes of LVADI in 78 patients (32%) from this cohort. Mean age (± standard deviation [SD]) was 57±15 years. The majority (94%) underwent Heartmate II implantation, with 62% LVADs placed as destination therapy. The most common type of LVADIs were driveline infections (47%), followed by bloodstream infections (24% VAD related, and 22% non-VAD related). The most common causative pathogens included gram-positive cocci (45%), predominantly staphylococci, and nosocomial gram-negative bacilli (27%). Almost half (42%) of the patients were managed by chronic suppressive antimicrobial therapy. While 14% of the patients had intraoperative debridement, only 3 underwent complete LVAD removal. The average duration (±SD) of LVAD support was 1.5±1.0 years. At year 2 of follow-up, the cumulative incidence of all-cause mortality was estimated to be 43%. Clinical manifestations of LVADI vary on the basis of the type of infection and the causative pathogen. Mortality remained high despite combined medical and surgical intervention and chronic suppressive antimicrobial therapy. Based on clinical experiences, a management algorithm for LVADI is proposed to assist in the decision-making process.

  16. Optimal Timing of Heart Transplant After HeartMate II Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Steffen, Robert J; Blackstone, Eugene H; Smedira, Nicholas G; Soltesz, Edward G; Hoercher, Katherine J; Thuita, Lucy; Starling, Randall C; Mountis, Maria; Moazami, Nader

    2017-11-01

    Optimal timing of heart transplantation in patients supported with second-generation left ventricular assist devices (LVADs) is unknown. Despite this, patients with LVADs continue to receive priority on the heart transplant waiting list. Our objective was to determine the optimal timing of transplantation for patients bridged with continuous-flow LVADs. A total of 301 HeartMate II LVADs (Thoratec Corp, Pleasanton, CA) were implanted in 285 patients from October 2004 to June 2013, and 86 patients underwent transplantation through the end of follow-up. Optimal transplantation timing was the product of surviving on LVAD support and surviving transplant. Three-year survival after both HeartMate II implantation and heart transplantation was unchanged when transplantation occurred within 9 months of implantation. Survival decreased as the duration of support exceeded this. Preoperative risk factors for death on HeartMate II support were prior valve operation, prior coronary artery bypass grafting, low albumin, low glomerular filtration rate, higher mean arterial pressure, hypertension, and earlier date of implant. Survival for patients without these risk factors was lowest when transplant was performed within 3 months but was relatively constant with increased duration of support. Longer duration of support was associated with poorer survival for patients with many of these risk factors. Device reimplantation, intracranial hemorrhage, and postimplant dialysis during HeartMate II support were associated with decreased survival. Survival of patients supported by the HeartMate II is affected by preoperative comorbidities and postoperative complications. Transplantation before complications is imperative in optimizing survival. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  17. The Use of Pediatric Ventricular Assist Devices in Children's Hospitals From 2000 to 2010: Morbidity, Mortality, and Hospital Charges.

    Science.gov (United States)

    Mansfield, Robert T; Lin, Kimberly Y; Zaoutis, Theoklis; Mott, Antonio R; Mohamad, Zeinab; Luan, Xianqun; Kaufman, Beth D; Ravishankar, Chitra; Gaynor, J William; Shaddy, Robert E; Rossano, Joseph W

    2015-07-01

    The use of ventricular assist devices has increased dramatically in adult heart failure patients. However, the overall use, outcome, comorbidities, and resource utilization of ventricular assist devices in pediatric patients have not been well described. We sought to demonstrate that the use of ventricular assist devices in pediatric patients has increased over time and that mortality has decreased. A retrospective study of the Pediatric Health Information System database was performed for patients 20 years old or younger undergoing ventricular assist device placement from 2000 to 2010. None. Four hundred seventy-five pediatric patients were implanted with ventricular assist devices during the study period: 69 in 2000-2003 (era 1), 135 in 2004-2006 (era 2), and 271 in 2007-2010 (era 3). Median age at ventricular assist device implantation was 6.0 years (interquartile range, 0.5-13.8), and the proportion of children who were 1-12 years old increased from 29% in era 1 to 47% in era 3 (p = 0.002). The majority of patients had a diagnosis of cardiomyopathy; this increased from 52% in era 1 to 72% in era 3 (p = 0.003). Comorbidities included arrhythmias (48%), pulmonary hypertension (16%), acute renal failure (34%), cerebrovascular disease (28%), and sepsis/systemic inflammatory response syndrome (34%). Two hundred forty-seven patients (52%) underwent heart transplantation and 327 (69%) survived to hospital discharge. Hospital mortality decreased from 42% in era 1 to 25% in era 3 (p = 0.004). Median hospital length of stay increased (37 d [interquartile range, 12-64 d] in era 1 vs 69 d [interquartile range, 35-130] in era 3; p interquartile range, $227,052-$853,318] in era 1 vs $1,577,983 [interquartile range, $874,463-$2,280,435] in era 3; p < 0.001). Factors associated with increased mortality include age less than 1 year (odds ratio, 2.04; 95% CI, 1.01-3.83), acute renal failure (odds ratio, 2.1; 95% CI, 1.26-3.65), cerebrovascular disease (odds ratio, 2.1; 95% CI, 1

  18. Right heart failure and "failure to thrive" after left ventricular assist device: clinical predictors and outcomes.

    Science.gov (United States)

    Baumwol, Jay; Macdonald, Peter S; Keogh, Anne M; Kotlyar, Eugene; Spratt, Phillip; Jansz, Paul; Hayward, Christopher S

    2011-08-01

    This study determined predictors of early post-operative right heart failure (RHF) and its consequences, as well as predictors of those who clinically thrive longer term after insertion of a continuous-flow left ventricular assist device (LVAD). Pre-operative and latest follow-up data were analyzed for 40 consecutive patients who received third-generation centrifugal-flow LVADs. RHF was defined using previously described criteria, including post-operative inotropes, pulmonary vasodilator use, or right-sided mechanical support. Patients were also categorized according to clinical outcomes after LVAD insertion. LVADs were implanted as a bridge to transplantation (BTT) in 33 patients and as destination therapy in 7. Before LVAD implant, 22 patients were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level 1, and 17 were at level 2. Temporary mechanical assistance was present in 50% of the cohort at LVAD implantation. The 6-month survival/progression to transplant was 92.5%. Average LVAD support time was 385 days (range, 21-1,011 days). RHF developed postoperatively in 13 of 40 patients (32.5%). RHF patients had more severe pre-operative tricuspid incompetence than non-RHF patients. The BTT patients with evidence of RHF had poorer survival to transplant (6 of 11 [54.5%]) than those without RHF (20 of 22 [90.9%]), p = 0.027). There were no other hemodynamic or echocardiographic predictors of short-term RHF. After LVAD, 22 of the 40 patients (55%) thrived clinically. For BTT patients, 20 of 21 (95%) of those who thrived progressed to transplant or were alive at latest follow-up vs 6 of 12 (50%) of those who failed to thrive (FTT; p thrived. Early post-operative RHF results in poorer survival/progression to transplantation for BTT patients and is predicted by greater pre-operative tricuspid incompetence. The most important predictor for those who will clinically thrive longer-term after LVAD insertion is younger age. Crown Copyright © 2011

  19. The successful implantation of continuous-flow left ventricular assist device as a destination therapy in Korea: echocardiographic assessment.

    Science.gov (United States)

    Lee, Ga Yeon; Park, Sung-Ji; Kim, Sujin; Choi, Namgyung; Jeong, Dong Seop; Jeon, Eun-Seok; Lee, Young Tak

    2014-01-01

    Left ventricular assist device (LVAD) is a good treatment option for the patients ineligible for cardiac transplantation. Several studies have demonstrated that a ventricular assist device improves the quality of life and prognosis of the patients with end-stage heart failure. A 75-yr-old man debilitated with New York Heart Association (NYHA) functional class III-IV due to severe left ventricular systolic dysfunction received LVAD implantation as a destination therapy. The patient was discharged with improved functional status (NYHA functional class II) after appropriate cardiac rehabilitation and education about how to manage the device and potential emergency situations. This is the first case of successful continuous-flow LVAD implantation as a destination therapy in Korea.

  20. Towards an Artificial Phonological Loop: An Assistive Device for Working Memory and Attentional Control

    Directory of Open Access Journals (Sweden)

    D. Bogen

    2006-01-01

    Full Text Available We describe the initial development of an artificial phonological loop (APL, a new technology to assist individuals with impairment of the working memory system. The phonological loop, along with the visuospatial sketchpad, is one of the two slave short-term memory subsystems that comprise working memory, a cognitive function closely associated with the control of attention. In the phonological loop, phonological (speech information lasting for 1–2 second is maintained active by repetitive, subvocal (silent speech rehearsal. Deficits in working memory, specifically in the phonological loop, occur in many disorders, including attention-deficit disorder and Alzheimer’s disease. In these disorders, it appears that the ability for phonological rehearsal is intact, but the regulation or triggering of the rehearsal process is inadequate, thus causing the contents of working memory to be lost. The purpose, then, of the APL is to facilitate the phonological loop by artificially extending the duration of phonological rehearsals. The APL mimics the natural phonological loop by providing audible vocal echoes to take the place of subvocal rehearsals. In this system, the user talks to him/herself in short (1–2 second phrases; the device records these phrases, stores them in electronic memory, and then repeats— i.e., echoes—the phrases multiple times over an extended period. Two versions of this device have been developed: the Echo-APL and the Rearticulation-APL. In the Echo-APL, only echoing is involved. In the Rearticulation-APL, however, the user re-vocalizes (rearticulates the phrase in response to an audible cue. The device repeats the cue until it detects (hears the re-vocalization. Future research and development of the APL will require extensive testing and careful evaluation of possible echo-schedules: the predefined program controlling inter-echo time intervals and echo-amplitude (echo loudness. The APL essentially exteriorizes the silent

  1. Outflow monitoring of a pneumatic ventricular assist device using external pressure sensors.

    Science.gov (United States)

    Kang, Seong Min; Her, Keun; Choi, Seong Wook

    2016-08-25

    In this study, a new algorithm was developed for estimating the pump outflow of a pneumatic ventricular assist device (p-VAD). The pump outflow estimation algorithm was derived from the ideal gas equation and determined the change in blood-sac volume of a p-VAD using two external pressure sensors. Based on in vitro experiments, the algorithm was revised to consider the effects of structural compliance caused by volume changes in an implanted unit, an air driveline, and the pressure difference between the sensors and the implanted unit. In animal experiments, p-VADs were connected to the left ventricles and the descending aorta of three calves (70-100 kg). Their outflows were estimated using the new algorithm and compared to the results obtained using an ultrasonic blood flow meter (UBF) (TS-410, Transonic Systems Inc., Ithaca, NY, USA). The estimated and measured values had a Pearson's correlation coefficient of 0.864. The pressure sensors were installed at the external controller and connected to the air driveline on the same side as the external actuator, which made the sensors easy to manage.

  2. Radio-frequency-assisted current startup in the Fusion Engineering Device

    International Nuclear Information System (INIS)

    Borowski, S.K.; Kammash, T.; Martin Peng, Y.K.

    1984-01-01

    Auxiliary radio-frequency (RF) heating of electrons before and during the current rise phase of a large tokamak, such as the Fusion Engineering Device (FED) (R 0 = 4.8 m, a = 1.3 m, sigma = 1.6, B(R 0 ) = 3.62 T), is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at about90 GHz is used to create a small volume of high conductivity plasma (T /sub e/ approx. = 100 eV, n /sub e/ approx. = 10 19 m -3 ) near the upper hybrid resonance (UHR) region. This plasma conditioning, referred to as preheating, permits a small radius (a 0 approx. = 0.2 to 0.4 m) current channel to be established with a relatively low initial loop voltage (less than or equal to 25 V as opposed to about 100 V without rf assist). During the subsequent plasma expansion and current rise phase, a combination of rf heating (up to 5 MW) and linear current ramping leads to a substantial savings in voltseconds by (a) minimizing the resistive flux consumption and (b) producing broad current density profiles. (With such broad profiles, the internal flux requirements are maintained at or near the flat profile limit.)

  3. Magnetic suspension of the rotor of a ventricular assist device of mixed flow type.

    Science.gov (United States)

    Horikawa, Oswaldo; de Andrade, Aron José Pazin; da Silva, Isaías; Bock, Eduardo Guy Perpetuo

    2008-04-01

    This work presents results of preliminary studies concerning application of magnetic bearing in a ventricular assist device (VAD) being developed by Dante Pazzanese Institute of Cardiology-IDPC (São Paulo, Brazil). The VAD-IDPC has a novel architecture that distinguishes from other known VADs. In this, the rotor has a conical geometry with spiral impellers, showing characteristics that are intermediate between a centrifugal VAD and an axial VAD. The effectiveness of this new type of blood pumping principle was showed by tests and by using it in heart surgery for external blood circulation. However, the developed VAD uses a combination of ball bearings and mechanical seals, limiting the life for some 10 h, making impossible its long-term use or its use as an implantable VAD. As a part of development of an implantable VAD, this work aims at the replacement of ball bearings by a magnetic bearing. The most important magnetic bearing principles are studied and the magnetic bearing developed by Escola Politécnica of São Paulo University (EPUSP-MB) is elected because of its very simple architecture. Besides presenting the principle of the EPUSP-MB, this work presents one possible alternative for applying the EPUSP-MB in the IDPC-VAD.

  4. Exercise guidelines for inpatients following ventricular assist device placement: a systematic review of the literature.

    Science.gov (United States)

    Scheiderer, Rachel; Belden, Courtney; Schwab, Darla; Haney, Casey; Paz, Jaime

    2013-06-01

    For patients with end-stage heart failure awaiting transplantation, lack of donor organs has created an increased need for alternatives such as left ventricular assist device (LVAD) implantation. The purpose of this study is to determine safe and effective exercise parameters for physical therapy in the acute care setting. A systematic literature review was conducted according to PRISMA guidelines using Sackett's Levels of Evidence to rate the evidence. Multiple databases were searched with inclusion criteria of: available in English, inpatient care up to 6 months postoperatively, description of intervention type and exercise parameters. no defined exercise parameters, outpatient treatment, infection post VAD, or palliative or hospice care post VAD. Six studies out of 1,291 articles met inclusion criteria. Common exercise parameters used were the Borg Rating of Perceived Exertion scale 11-13 (6-20 scale) or > 4 (0-10 scale), Dyspnea scale > 2 (0-4 scale) and > 5 (0-10 scale), mean arterial pressure (MAP) 70-95 mmHg, and LVAD flow > 3L/min. Levels of evidence ranged from case controlled to expert opinion. Current evidence on inpatient exercise parameters for patient's status post LVAD implantation is not sufficient to suggest definitive guidelines; however, these exercise parameters provide a reference for patient care.

  5. Identification of non-HLA antibodies in ventricular assist device recipients

    Directory of Open Access Journals (Sweden)

    Sandy von Salisch

    2013-11-01

    Full Text Available Aims Recipients of ventricular assist devices (VADR have a higher incidence to develop antibodies (Abs against human leukocyte antigens (HLA. Non-HLA antibodies like major histocompatibility complex class I-related chain A (MICA and autoantibodies against angiotensin type 1 receptor (AT1R and endothelin receptor A (ETAR are also implicated in the pathogenesis of acute rejection and allograft vasculopathy. We monitored non-HLA- and HLA-Abs in VADR up to one year after implantation. Materials and methods Sera of 56 VADR (54.1±12.8 years old, 50 men were analyzed for Abs against HLA-, MICA-, AT1R- and ETAR several times over one year after implantation using ELISA and Luminex xMAP technology. Blood transfusions, gender and age were reviewed. Results Sera of 56 VADR (54.1±12.8 years old, 50 men were analyzed for Abs against HLA-, MICA-, AT1R- and ETAR several times over one year after implantation using ELISA and Luminex xMAP technology. Blood transfusions, gender and age were reviewed. Conclusion Beside HLA- and MICA-Abs, VADR showed high titres of Abs against AT1R or ETAR, which underlines the necessity for monitoring non-HLA antibodies in VADR prior heart transplantation.

  6. Impact of Vice President Cheney on public interest in left ventricular assist devices and heart transplantation.

    Science.gov (United States)

    Pandey, Ambarish; Abdullah, Kazeen; Drazner, Mark H

    2014-05-01

    Although celebrity illnesses attract a significant amount of media attention in the United States, there are few studies that have looked at how celebrity health conditions impact the awareness of the illness in the general population. Recently, Vice President Cheney underwent left ventricular assist device (LVAD) implantation and subsequently a cardiac transplant. The aim of this study was to determine whether there was evidence of increased interest in these 2 procedures as assessed by social media. We determined the relative frequency of Google searches for LVAD and heart transplantation from 2004 to 2013 using Google trends. We also counted the number of YouTube videos and Twitter messages posted monthly concerning LVADs over a 7-year time frame. There was a significant spike in the Google search interest for LVAD and heart transplantation in the month when Vice President Cheney underwent the respective procedure. Similarly, there was a large increase in YouTube videos and Twitter messages concerning LVADs shortly after he was implanted. In total, these data support the concept that a public figure's illness can significantly influence the public's interest in that condition and its associated therapies. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Palliative medicine consultation for preparedness planning in patients receiving left ventricular assist devices as destination therapy.

    Science.gov (United States)

    Swetz, Keith M; Freeman, Monica R; AbouEzzeddine, Omar F; Carter, Kari A; Boilson, Barry A; Ottenberg, Abigale L; Park, Soon J; Mueller, Paul S

    2011-06-01

    To assess the benefit of proactive palliative medicine consultation for delineation of goals of care and quality-of-life preferences before implantation of left ventricular assist devices as destination therapy (DT). We retrospectively reviewed the cases of patients who received DT between January 15, 2009, and January 1, 2010. Of 19 patients identified, 13 (68%) received proactive palliative medicine consultation. Median time of palliative medicine consultation was 1 day before DT implantation (range, 5 days before to 16 days after). Thirteen patients (68%) completed advance directives. The DT implantation team and families reported that preimplantation discussions and goals of care planning made postoperative care more clear and that adverse events were handled more effectively. Currently, palliative medicine involvement in patients receiving DT is viewed as routine by cardiac care specialists. Proactive palliative medicine consultation for patients being considered for or being treated with DT improves advance care planning and thus contributes to better overall care of these patients. Our experience highlights focused advance care planning, thorough exploration of goals of care, and expert symptom management and end-of-life care when appropriate.

  8. Evaluation of gait performance of knee osteoarthritis patients after total knee arthroplasty with different assistive devices

    Directory of Open Access Journals (Sweden)

    Ana Tereso

    Full Text Available IntroductionNowadays Knee Osteoarthritis (KOA affects a large percentage of the elderly, and one solution is to perform a Total Knee Arthroplasty (TKA. In this paper, one intends to study the gait and posture of these patients after the TKA, while walking with three assistive devices (ADs (crutches, standard walker (SW and rollator with forearm supports (RFS.MethodsEleven patients were evaluated in 2 phases: 5 days and 15 days after surgery. This evaluation was conducted with two inertial sensors, one attached to the operated leg ankle, to measure spatiotemporal parameters, and the other at the sacrum, to measure posture and fall risk-related parameters. Multivariate analysis of variance (MANOVA with repeated measures was performed to detect group differences.ResultsThe MANOVA results show that all spatiotemporal parameters are significantly different (p0.05. The interaction between time and ADs only affects significantly the velocity (p<0.05. In terms of fall risk parameters, time only significantly affects the antero-posterior direction (p<0.05 and ADs affects significantly root mean square in medio-lateral direction (p<0.05. In terms of interaction between time and ADs, there are no statistical significant differences.ConclusionThis study concludes that depending on the state of recovery of the patient, different ADs should be prescribed. On the overall, standard walker is good to give stability to the patient and RFS allows the patient to present a gait pattern closer to a natural gait.

  9. The Heartmate III: design and in vivo studies of a maglev centrifugal left ventricular assist device.

    Science.gov (United States)

    Loree, H M; Bourque, K; Gernes, D B; Richardson, J S; Poirier, V L; Barletta, N; Fleischli, A; Foiera, G; Gempp, T M; Schoeb, R; Litwak, K N; Akimoto, T; Kameneva, M; Watach, M J; Litwak, P

    2001-05-01

    A compact implantable centrifugal left ventricular assist device (LVAD) (HeartMate III) featuring a magnetically levitated impeller is under development. The goal of our ongoing work is to demonstrate feasibility, low hemolysis, and low thrombogenicity of the titanium pump in chronic bovine in vivo studies. The LVAD is based on so-called bearingless motor technology and combines pump rotor, drive, and magnetic bearing functions in a single unit. The impeller is rotated (theta z) and levitated with both active (X, Y) and passive (Z, theta x, theta y) suspension. Six prototype systems have been built featuring an implantable titanium pump (69 mm diameter, 30 mm height) with textured blood contacting surfaces and extracorporeal electronics. The pumps were implanted in 9 calves (< or = 100 kg at implant) that were anticoagulated with Coumadin (2.5 < or = INR < or = 4.0) throughout the studies. Six studies were electively terminated (at 27-61 days), 1 study was terminated after the development of severe pneumonia and lung atelectasis (at 27 days) another study was terminated after cardiac arrest (at 2 days) while a final study is ongoing (at approximately 100 days). Mean pump flows ranged from 2 to 7 L/min, except for brief periods of exercise at 6 to 9 L/min. Plasma free hemoglobin ranged from 4 to 10 mg/dl. All measured biochemical indicators of end organ function remained within normal range. The pumps have met performance requirements in all 9 implants with acceptable hemolysis and no mechanical failures.

  10. Implant Strategy-Specific Changes in Symptoms in Response to Left Ventricular Assist Devices.

    Science.gov (United States)

    Lee, Christopher S; Gelow, Jill M; Chien, Christopher V; Hiatt, Shirin O; Bidwell, Julie T; Denfeld, Quin E; Grady, Kathleen L; Mudd, James O

    Although we know that the quality of life generally improves after left ventricular assist device (LVAD) implantation, we know little about how symptoms change in response to LVAD. The purpose of this study was to compare the changes in symptoms between bridge and destination therapy patients as part of a prospective cohort study. Physical (dyspnea and wake disturbances) and affective symptoms (depression and anxiety) were measured before LVAD and at 1, 3, and 6 months after LVAD. Multiphase growth modeling was used to capture the 2 major phases of change: initial improvements between preimplant and 1 month after LVAD and subsequent improvements between 1 and 6 months after LVAD. The sample included 64 bridge and 22 destination therapy patients as the preimplant strategy. Destination patients had worse preimplant dyspnea and wake disturbances, and they experienced greater initial improvements in these symptoms compared with bridge patients (all P .05). Destination patients had worse preimplant depression (P = .042) but experienced similar initial and subsequent improvements in depression in response to LVAD compared with bridge patients (both P > .05). Destination patients had similar preimplant anxiety (P = .279) but experienced less initial and greater subsequent improvements in anxiety after LVAD compared with bridge patients (both P < .05). There are many differences in the magnitude and timing of change in symptom responses to LVAD between bridge and destination therapy patients. Detailed information on changes in specific symptoms may better inform shared decision-making regarding LVAD.

  11. The impact of different types of assistive devices on gait measures and safety in Huntington's disease.

    Directory of Open Access Journals (Sweden)

    Anne D Kloos

    Full Text Available BACKGROUND: Gait and balance impairments lead to frequent falls and injuries in individuals with Huntington's disease (HD. Assistive devices (ADs such as canes and walkers are often prescribed to prevent falls, but their efficacy is unknown. We systematically examined the effects of different types of ADs on quantitative gait measures during walking in a straight path and around obstacles. METHODS: Spatial and temporal gait parameters were measured in 21 subjects with HD as they walked across a GAITRite walkway under 7 conditions (i.e., using no AD and 6 commonly prescribed ADs: a cane, a weighted cane, a standard walker, and a 2, 3 or 4 wheeled walker. Subjects also were timed and observed for number of stumbles and falls while walking around two obstacles in a figure-of-eight pattern. RESULTS: Gait measure variability (i.e., coefficient of variation, an indicator of fall risk, was consistently better when using the 4WW compared to other ADs. Subjects also walked the fastest and had the fewest number of stumbles and falls when using the 4WW in the figure-of-eight course. Subjects walked significantly slower using ADs compared to no AD both across the GAITRite and in the figure-of-eight. Measures reflecting gait stability and safety improved with the 4WW but were made worse by some other ADs.

  12. The impact of different types of assistive devices on gait measures and safety in Huntington's disease.

    Science.gov (United States)

    Kloos, Anne D; Kegelmeyer, Deborah A; White, Susan E; Kostyk, Sandra K

    2012-01-01

    Gait and balance impairments lead to frequent falls and injuries in individuals with Huntington's disease (HD). Assistive devices (ADs) such as canes and walkers are often prescribed to prevent falls, but their efficacy is unknown. We systematically examined the effects of different types of ADs on quantitative gait measures during walking in a straight path and around obstacles. Spatial and temporal gait parameters were measured in 21 subjects with HD as they walked across a GAITRite walkway under 7 conditions (i.e., using no AD and 6 commonly prescribed ADs: a cane, a weighted cane, a standard walker, and a 2, 3 or 4 wheeled walker). Subjects also were timed and observed for number of stumbles and falls while walking around two obstacles in a figure-of-eight pattern. Gait measure variability (i.e., coefficient of variation), an indicator of fall risk, was consistently better when using the 4WW compared to other ADs. Subjects also walked the fastest and had the fewest number of stumbles and falls when using the 4WW in the figure-of-eight course. Subjects walked significantly slower using ADs compared to no AD both across the GAITRite and in the figure-of-eight. Measures reflecting gait stability and safety improved with the 4WW but were made worse by some other ADs.

  13. Influence of vascular network design on gas transfer in lung assist device technology.

    Science.gov (United States)

    Bassett, Erik K; Hoganson, David M; Lo, Justin H; Penson, Elliot J N; Vacanti, Joseph P

    2011-01-01

    Blood oxygenators are vital for the critically ill, but their use is limited to the hospital setting. A portable blood oxygenator or a lung assist device for ambulatory or long-term use would greatly benefit patients with chronic lung disease. In this work, a biomimetic blood oxygenator system was developed which consisted of a microfluidic vascular network covered by a gas permeable silicone membrane. This system was used to determine the influence of key microfluidic parameters-channel size, oxygen exposure length, and blood shear rate-on blood oxygenation and carbon dioxide removal. Total gas transfer increased linearly with flow rate, independent of channel size and oxygen exposure length. On average, CO(2) transfer was 4.3 times higher than oxygen transfer. Blood oxygen saturation was also found to depend on the flow rate per channel but in an inverse manner; oxygenation decreased and approached an asymptote as the flow rate per channel increased. These relationships can be used to optimize future biomimetic vascular networks for specific lung applications: gas transfer for carbon dioxide removal in patients with chronic obstructive pulmonary disease or oxygenation for premature infants requiring complete lung replacement therapy.

  14. Anesthesia for left ventricular assist device insertion: a case series and review.

    Science.gov (United States)

    Broussard, David; Donaldson, Emilie; Falterman, Jason; Bates, Michael

    2011-01-01

    From October 2008 to June 2010, a total of 42 patients had the HeartMate II left ventricular assist device inserted surgically at Ochsner Medical Center in New Orleans, LA. A retrospective electronic record review was conducted on this series of patients to analyze elements of perioperative anesthetic care, including general anesthetic care, echocardiographic considerations, and blood product usage. Etomidate was used to induce anesthesia for 34 of 42 patients (81%) in this series, with an average dose of 16.5 mg (±6 mg). The average intraoperative fentanyl dose was 1,318 µg (±631 µg). On average, patients were extubated 91 hours (±72 hours) after arrival to the intensive care unit and left on day 9 (±5 days). The average left ventricular ejection fraction of the patients in this series was 13% (±5%). Sixteen patients were evaluated as having severe right-heart dysfunction preoperatively. Two of 42 patients required surgical closure of echocardiographically identified patent foramen ovale. Twelve of 42 patients underwent surgical correction of tricuspid regurgitation. On average, 3 units (±2.6 units) of fresh frozen plasma were transfused intraoperatively and 10 units postoperatively. Intraoperative red blood cell usage averaged 1.1 units (maximum, 7 units), with an average 9.3 units administered in the first 48 hours postoperatively.

  15. Developments in control systems for rotary left ventricular assist devices for heart failure patients: a review

    International Nuclear Information System (INIS)

    AlOmari, Abdul-Hakeem H; Savkin, Andrey V; Lovell, Nigel H; Stevens, Michael; Mason, David G; Timms, Daniel L; Salamonsen, Robert F

    2013-01-01

    From the moment of creation to the moment of death, the heart works tirelessly to circulate blood, being a critical organ to sustain life. As a non-stopping pumping machine, it operates continuously to pump blood through our bodies to supply all cells with oxygen and necessary nutrients. When the heart fails, the supplement of blood to the body's organs to meet metabolic demands will deteriorate. The treatment of the participating causes is the ideal approach to treat heart failure (HF). As this often cannot be done effectively, the medical management of HF is a difficult challenge. Implantable rotary blood pumps (IRBPs) have the potential to become a viable long-term treatment option for bridging to heart transplantation or destination therapy. This increases the potential for the patients to leave the hospital and resume normal lives. Control of IRBPs is one of the most important design goals in providing long-term alternative treatment for HF patients. Over the years, many control algorithms including invasive and non-invasive techniques have been developed in the hope of physiologically and adaptively controlling left ventricular assist devices and thus avoiding such undesired pumping states as left ventricular collapse caused by suction. In this paper, we aim to provide a comprehensive review of the developments of control systems and techniques that have been applied to control IRBPs. (topical review)

  16. Pulse Oximeter Derived Blood Pressure Measurement in Patients With a Continuous Flow Left Ventricular Assist Device.

    Science.gov (United States)

    Hellman, Yaron; Malik, Adnan S; Lane, Kathleen A; Shen, Changyu; Wang, I-Wen; Wozniak, Thomas C; Hashmi, Zubair A; Munson, Sarah D; Pickrell, Jeanette; Caccamo, Marco A; Gradus-Pizlo, Irmina; Hadi, Azam

    2017-05-01

    Currently, blood pressure (BP) measurement is obtained noninvasively in patients with continuous flow left ventricular assist device (LVAD) by placing a Doppler probe over the brachial or radial artery with inflation and deflation of a manual BP cuff. We hypothesized that replacing the Doppler probe with a finger-based pulse oximeter can yield BP measurements similar to the Doppler derived mean arterial pressure (MAP). We conducted a prospective study consisting of patients with contemporary continuous flow LVADs. In a small pilot phase I inpatient study, we compared direct arterial line measurements with an automated blood pressure (ABP) cuff, Doppler and pulse oximeter derived MAP. Our main phase II study included LVAD outpatients with a comparison between Doppler, ABP, and pulse oximeter derived MAP. A total of five phase I and 36 phase II patients were recruited during February-June 2014. In phase I, the average MAP measured by pulse oximeter was closer to arterial line MAP rather than Doppler (P = 0.06) or ABP (P < 0.01). In phase II, pulse oximeter MAP (96.6 mm Hg) was significantly closer to Doppler MAP (96.5 mm Hg) when compared to ABP (82.1 mm Hg) (P = 0.0001). Pulse oximeter derived blood pressure measurement may be as reliable as Doppler in patients with continuous flow LVADs. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  17. Impact of left ventricular assist device speed adjustment on exercise tolerance and markers of wall stress.

    Science.gov (United States)

    Hayward, Christopher S; Salamonsen, Robert; Keogh, Anne M; Woodard, John; Ayre, Peter; Prichard, Roslyn; Kotlyar, Eugene; Macdonald, Peter S; Jansz, Paul; Spratt, Phillip

    2015-09-01

    Left ventricular assist devices are crucial in rehabilitation of patients with end-stage heart failure. Whether cardiopulmonary function is enhanced with higher pump output is unknown. 10 patients (aged 39±16 years, mean±SD) underwent monitored adjustment of pump speed to determine minimum safe low speed and maximum safe high speed at rest. Patients were then randomized to these speed settings and underwent three 6-minute walk tests (6MWT) and symptom-limited cardiopulmonary stress tests (CPX) on separate days. Pump speed settings (low, normal and high) resulted in significantly different resting pump flows of 4.43±0.6, 5.03±0.94, and 5.72±1.2 l/min (Pexercise (Pexercise time (p=.27). Maximum workload achieved and peak oxygen consumption were significantly different comparing low to high pump speed settings only (Prelease was significantly reduced at higher pump speed with exercise (Prelease consistent with lower myocardial wall stress. This did not, however, improve exercise tolerance.

  18. Developments in control systems for rotary left ventricular assist devices for heart failure patients: a review.

    Science.gov (United States)

    AlOmari, Abdul-Hakeem H; Savkin, Andrey V; Stevens, Michael; Mason, David G; Timms, Daniel L; Salamonsen, Robert F; Lovell, Nigel H

    2013-01-01

    From the moment of creation to the moment of death, the heart works tirelessly to circulate blood, being a critical organ to sustain life. As a non-stopping pumping machine, it operates continuously to pump blood through our bodies to supply all cells with oxygen and necessary nutrients. When the heart fails, the supplement of blood to the body's organs to meet metabolic demands will deteriorate. The treatment of the participating causes is the ideal approach to treat heart failure (HF). As this often cannot be done effectively, the medical management of HF is a difficult challenge. Implantable rotary blood pumps (IRBPs) have the potential to become a viable long-term treatment option for bridging to heart transplantation or destination therapy. This increases the potential for the patients to leave the hospital and resume normal lives. Control of IRBPs is one of the most important design goals in providing long-term alternative treatment for HF patients. Over the years, many control algorithms including invasive and non-invasive techniques have been developed in the hope of physiologically and adaptively controlling left ventricular assist devices and thus avoiding such undesired pumping states as left ventricular collapse caused by suction. In this paper, we aim to provide a comprehensive review of the developments of control systems and techniques that have been applied to control IRBPs.

  19. A Novel Mean-Value Model of the Cardiovascular System Including a Left Ventricular Assist Device.

    Science.gov (United States)

    Ochsner, Gregor; Amacher, Raffael; Schmid Daners, Marianne

    2017-06-01

    Time-varying elastance models (TVEMs) are often used for simulation studies of the cardiovascular system with a left ventricular assist device (LVAD). Because these models are computationally expensive, they cannot be used for long-term simulation studies. In addition, their equilibria are periodic solutions, which prevent the extraction of a linear time-invariant model that could be used e.g. for the design of a physiological controller. In the current paper, we present a new type of model to overcome these problems: the mean-value model (MVM). The MVM captures the behavior of the cardiovascular system by representative mean values that do not change within the cardiac cycle. For this purpose, each time-varying element is manually converted to its mean-value counterpart. We compare the derived MVM to a similar TVEM in two simulation experiments. In both cases, the MVM is able to fully capture the inter-cycle dynamics of the TVEM. We hope that the new MVM will become a useful tool for researchers working on physiological control algorithms. This paper provides a plant model that enables for the first time the use of tools from classical control theory in the field of physiological LVAD control.

  20. Experimental Assessment of the Hydraulics of a Miniature Axial-Flow Left Ventricular Assist Device

    Science.gov (United States)

    Smith, P. Alex; Cohn, William; Metcalfe, Ralph

    2017-11-01

    A minimally invasive partial-support left ventricular assist device (LVAD) has been proposed with a flow path from the left atrium to the arterial system to reduce left ventricular stroke work. In LVAD design, peak and average efficiency must be balanced over the operating range to reduce blood trauma. Axial flow pumps have many geometric parameters. Until recently, testing all these parameters was impractical, but modern 3D printing technology enables multi-parameter studies. Following theoretical design, experimental hydraulic evaluation in steady state conditions examines pressure, flow, pressure-flow gradient, efficiency, torque, and axial force as output parameters. Preliminary results suggest that impeller blades and stator vanes with higher inlet angles than recommended by mean line theory (MLT) produce flatter gradients and broader efficiency curves, increasing compatibility with heart physiology. These blades also produce less axial force, which reduces bearing load. However, they require slightly higher torque, which is more demanding of the motor. MLT is a low order, empirical model developed on large pumps. It does not account for the significant viscous losses in small pumps like LVADs. This emphasizes the importance of experimental testing for hydraulic design. Roderick D MacDonald Research Fund.

  1. Biventricular Hypertrophic Cardiomyopathy in a Child with LEOPARD Syndrome: a Case Report

    Directory of Open Access Journals (Sweden)

    Blesneac Cristina

    2017-12-01

    Full Text Available Background: LEOPARD syndrome is a complex dysmorphogenetic disorder of inconstant penetrance and various morphologic expressions. The syndrome is an autosomal dominant disease that features multiple lentigines, electrocardiographic changes, eye hypertelorism, pulmonary valve stenosis or hypertrophic cardiomyopathy, genital malformations, and a delayed constitutional growth hearing loss, which can be associated with rapidly progressive severe biventricular obstructive hypertrophic cardiomyopathy. No epidemiologic data are available on the real incidence of LEOPARD syndrome; however, this seems to be a rare disease, being often underdiagnosed, as many of its features are mild.

  2. Biventricular heart failure secondary to a pericardial cystic mass: case report

    Energy Technology Data Exchange (ETDEWEB)

    Nizzero, A. [Sudbury Regional Hospital, Dept. of Diagnostic Imaging, Sudbury, Ontario (Canada); Dobranowski, J. [St. Joseph' s Hospital, Dept. of Radiology, Hamilton, Ontario (Canada); Tanser, P. [St. Joseph' s Hospital, Dept. of Cardiology, Hamilton, Ontario (Canada)

    2000-07-01

    Cystic masses of the pericardium causing symptoms due to cardiac compression are very unusual. Such cysts may be congenital, or they may occur secondary to inflammatory processes or hemorrhage, similar to cysts seen in the pleura or peritoneum. Echocardiography, computed tomography (CT) and magnetic resonance imaging (MRI) are useful for noninvasive investigation of the pericardium, although in the remote past, definitive diagnosis was possible only with thoracotomy. We present a case of biventricular cardiac failure secondary to a calcified pericardial cystic mass in a patient with constrictive pericarditis. Because of the extensive calcification, echocardiography was not helpful. CT and MRI allowed excellent delineation of the nature and effects of this abnormality. (author)

  3. Energy costs of manual therapy: effects of plinth height and an assistive device.

    Science.gov (United States)

    O'Connell, D G; Holmes, C F; Santos, J L; Jordan, E; Acosta, F

    1994-01-01

    significantly greater during E than the SMTH condition. RPE for S was significantly greater than SMTH, E, or EMTH. It can be concluded that the MTH significantly reduced the physiologic cost of providing manual therapy at either standard or elevated plinth height. further studies on these types of assistive devices and the effects of health status of the therapist on the provision of manual therapy treatments at various plinth heights are needed.

  4. Metabolic volume performs better than SUVmax in the detection of left ventricular assist device driveline infection

    Energy Technology Data Exchange (ETDEWEB)

    Avramovic, Nemanja; Weckesser, Matthias; Milankovic, Danka; Vrachimis, Alexis; Wenning, Christian [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Dell' Aquila, Angelo Maria; Sindermann, Juergen R. [University Hospital Muenster, Department of Cardiac Surgery, Muenster (Germany)

    2017-10-15

    A continuous-flow left ventricular assist device (LVAD) is a new and highly promising therapy in supporting end-stage heart failure patients, either bridging them to heart transplantation or as a destination therapy. Infection is one of the major complications associated with LVAD implants. {sup 18}F-FDG PET/CT has already been shown to be useful in the detection of LVAD infection. The goal of this study was to compare the diagnostic accuracy of different PET analysis techniques (visual grading versus SUVmax and metabolic volume). We retrospectively analyzed 48 patients with implanted LVAD who underwent an {sup 18}F-FDG PET/CT that were either suspected to have a driveline or device infection or inflammation of unknown origin. PET/CT was analyzed qualitatively (visual grading) and quantitatively (SUVmax and metabolic volume) and matched to the final clinical diagnosis concerning driveline infection. The final diagnosis (standard of reference) was made at the end of clinically recorded follow-up or transplantation and included microbiological cultures of the driveline exit site and/or surgical samples, and clinical signs of infection despite negative cultures as well as recurrence of symptoms. Sensitivity, specificity, positive and negative predictive value were 87.5%, 79%, 81% and 86% for visual score, 87.5%, 87.5%, 87.5% and 87.5% for SUVmax and 96%, 87.5%, 88.5%, 95.5% for metabolic volume, respectively. ROC analysis revealed an AUC of.929 for SUVmax and.969 for metabolic volume. Both SUVmax and metabolic volume had a high detection rate of patients with driveline infection (21/24 = 91.5% true positive vs. 23/26 = 88.5% true positive, respectively). However, metabolic volume detected more patients without any infection correctly (1/22 = 4.5% false negative vs. 3/24 = 12.5% false negative). {sup 18}F-FDG PET/CT is a valuable tool for the diagnosis of LVAD driveline infection with high diagnostic accuracy. Particularly the use of the metabolic volume yields very

  5. Pulsatile operation of a continuous-flow right ventricular assist device (RVAD) to improve vascular pulsatility.

    Science.gov (United States)

    Ng, Boon C; Kleinheyer, Matthias; Smith, Peter A; Timms, Daniel; Cohn, William E; Lim, Einly

    2018-01-01

    Despite the widespread acceptance of rotary blood pump (RBP) in clinical use over the past decades, the diminished flow pulsatility generated by a fixed speed RBP has been regarded as a potential factor that may lead to adverse events such as vasculature stiffening and hemorrhagic strokes. In this study, we investigate the feasibility of generating physiological pulse pressure in the pulmonary circulation by modulating the speed of a right ventricular assist device (RVAD) in a mock circulation loop. A rectangular pulse profile with predetermined pulse width has been implemented as the pump speed pattern with two different phase shifts (0% and 50%) with respect to the ventricular contraction. In addition, the performance of the speed modulation strategy has been assessed under different cardiovascular states, including variation in ventricular contractility and pulmonary arterial compliance. Our results indicated that the proposed pulse profile with optimised parameters (Apulse = 10000 rpm and ωmin = 3000 rpm) was able to generate pulmonary arterial pulse pressure within the physiological range (9-15 mmHg) while avoiding undesirable pump backflow under both co- and counter-pulsation modes. As compared to co-pulsation, stroke work was reduced by over 44% under counter-pulsation, suggesting that mechanical workload of the right ventricle can be efficiently mitigated through counter-pulsing the pump speed. Furthermore, our results showed that improved ventricular contractility could potentially lead to higher risk of ventricular suction and pump backflow, while stiffening of the pulmonary artery resulted in increased pulse pressure. In conclusion, the proposed speed modulation strategy produces pulsatile hemodynamics, which is more physiologic than continuous blood flow. The findings also provide valuable insight into the interaction between RVAD speed modulation and the pulmonary circulation under various cardiovascular states.

  6. Comparison of fasciotomy wound closures using traditional dressing changes and the vacuum-assisted closure device.

    Science.gov (United States)

    Zannis, John; Angobaldo, Jeff; Marks, Malcolm; DeFranzo, Anthony; David, Lisa; Molnar, Joseph; Argenta, Louis

    2009-04-01

    Fasciotomy wounds can be a major contributor to length of stay for patients as well as a difficult reconstructive challenge. Once the compartment pressure has been relieved and stabilized, the wound should be closed as quickly and early as possible to avoid later complications. Skin grafting can lead to morbidity and scarring at both the donor and fasciotomy site. Primary closure results in a more functional and esthetic outcome with less morbidity for the patient, but can often be difficult to achieve secondary to edema, skin retraction, and skin edge necrosis. Our objective was to examine fasciotomy wound outcomes, including time to definitive closure, comparing traditional wet-to-dry dressings, and the vacuum-assisted closure (VAC) device. This retrospective chart review included a consecutive series of patients over a 10-year period. This series included 458 patients who underwent 804 fasciotomies. Of these fasciotomy wounds, 438 received exclusively VAC. dressings, 270 received only normal saline wet-to-dry dressings, and 96 were treated with a combination of both. Of the sample, 408 patients were treated with exclusively VAC therapy or wet-to-dry dressings and 50 patients were treated with a combination of both. In comparing all wounds, there was a statistically significant higher rate of primary closure using the VAC versus traditional wet-to-dry dressings (P lower extremities and P extremities). The time to primary closure of wounds was shorter in the VAC. group in comparison with the non-VAC group. This study has shown that the use of the VAC for fasciotomy wound closure results in a higher rate of primary closure versus traditional wet-to-dry dressings. In addition, the time to primary closure of wounds or time to skin grafting is shorter when the VAC was employed. The VAC used in the described settings decreases hospitalization time, allows for earlier rehabilitation, and ultimately leads to increased patient satisfaction.

  7. The effect of ventricular assist devices on cerebral blood flow and blood pressure fractality

    International Nuclear Information System (INIS)

    Bellapart, Judith; Fraser, John F; Chan, Gregory S H; Tzeng, Yu-Chieh; Ainslie, Philip N; Dunster, Kimble R; Barnett, Adrian G; Boots, Rob

    2011-01-01

    Biological signals often exhibit self-similar or fractal scaling characteristics which may reflect intrinsic adaptability to their underlying physiological system. This study analysed fractal dynamics of cerebral blood flow in patients supported with ventricular assist devices (VAD) to ascertain if sustained modifications of blood pressure waveform affect cerebral blood flow fractality. Simultaneous recordings of arterial blood pressure and cerebral blood flow velocity using transcranial Doppler were obtained from five cardiogenic shock patients supported by VAD, five matched control patients and five healthy subjects. Computation of a fractal scaling exponent (α) at the low-frequency time scale by detrended fluctuation analysis showed that cerebral blood flow velocity exhibited 1/f fractal scaling in both patient groups (α = 0.95 ± 0.09 and 0.97 ± 0.12, respectively) as well as in the healthy subjects (α = 0.86 ± 0.07). In contrast, fluctuation in blood pressure was similar to non-fractal white noise in both patient groups (α = 0.53 ± 0.11 and 0.52 ± 0.09, respectively) but exhibited 1/f scaling in the healthy subjects (α = 0.87 ± 0.04, P < 0.05 compared with the patient groups). The preservation of fractality in cerebral blood flow of VAD patients suggests that normal cardiac pulsation and central perfusion pressure changes are not the integral sources of cerebral blood flow fractality and that intrinsic vascular properties such as cerebral autoregulation may be involved. However, there is a clear difference in the fractal scaling properties of arterial blood pressure between the cardiogenic shock patients and the healthy subjects

  8. Sex and intimacy among patients with implantable left-ventricular assist devices.

    Science.gov (United States)

    Marcuccilli, Linda; Casida, Jesus Jessie; Peters, Rosalind M; Wright, Susan

    2011-01-01

    Left-ventricular assist devices (LVADs) sustain and improve the quality of life of people living with an advanced stage of heart failure. Past research focused on the development and advancement of LVAD technology, complications, and survival rates. Limited research addressed the psychosocial aspects of living with an LVAD, yet research related to sexual functioning and intimacy is lacking. The purpose of this study was to explore and describe sex and intimacy among adults living with an LVAD. We used an interpretive phenomenological study to explore the experiences of adults living with a long-term implantable LVAD, including the effect of the LVAD on their intimate and sexual functioning. Semistructured interviews were conducted with 7 men and 2 women, 31 to 70 years of age, who had lived with the LVAD at home for at least 3 months. Interviews were audiorecorded and transcribed. The wholistic and selective approach by van Manen (Researching Lived Experience: Human Science for an Action Sensitive Pedagogy. Albany, NY: SUNY Press; 1990) guided the analysis and interpretation of the transcribed interviews. Data were organized and coded into words and phrases using qualitative software. Three themes emerged from the data: (a) improved sexual relations with LVAD, (b) sexual adjustment, and (c) nonsexual intimacy. The themes identified were consistent with the concept of normalcy from the theory of self-care. Participants reported that as the LVAD improved their overall health, their sexual functioning also improved. Participants also reported an increased sense of connectedness and intimacy with their partners even in the absence of sexual intercourse. Participants discussed ways in which they continued to develop intimate relationships even in the presence of limitations in structural and functional integrity. The knowledge derived from this study can be used as a guide for healthcare providers in counseling LVAD recipients on psychosocial and sexual health essential

  9. Preoperative atrial fibrillation increases risk of thromboembolic events after left ventricular assist device implantation.

    Science.gov (United States)

    Stulak, John M; Deo, Salil; Schirger, John; Aaronson, Keith D; Park, Soon J; Joyce, Lyle D; Daly, Richard C; Pagani, Francis D

    2013-12-01

    Because no series has specifically analyzed the impact of preoperative atrial fibrillation (AF) on patients already at higher risk of thromboembolism after implantation of a left ventricular assist device (LVAD), we review our experience with these patients. Between July 2003 and September 2011, 389 patients (308 male) underwent implantation of a continuous flow LVAD at University of Michigan Hospital and Mayo Clinic. Median age at implant was 60 years (range, 18 to 79 years). Preoperative AF was present in 120 patients (31%). Outcomes were analyzed for the association of preoperative AF and postoperative thromboembolic (TE) events defined as stroke, transient ischemic attack, hemolysis, or pump thrombosis. Thromboembolic events occurring within the first 30 days were not counted. One hundred thirty-eight TEs events occurred in 97/389 patients (25%) for an event rate of 0.31 TE events/patient-years of support. Freedom from a TE event in patients with preoperative AF was 62% at 1 year and 46% at 2 years compared with 79% and 72% at 1 and 2 years, respectively, in patients without preoperative AF (p < 0.001). Median survival was 10 months (maximum 7.2 years, total 439 patient-years). Preoperative AF did not decrease late survival at 1 and 2 years after LVAD implant (preop AF: 85% and 70% versus no preop AF: 82% and 70%, respectively; p = 0.55). Patients with preoperative AF have a lower freedom from TE events after LVAD implant. While overall late survival was not significantly reduced in these patients, refinement in anticoagulation strategies after VAD implant may be required. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  10. Frailty and outcomes after implantation of left ventricular assist device as destination therapy.

    Science.gov (United States)

    Dunlay, Shannon M; Park, Soon J; Joyce, Lyle D; Daly, Richard C; Stulak, John M; McNallan, Sheila M; Roger, Véronique L; Kushwaha, Sudhir S

    2014-04-01

    Frailty is recognized as a major prognostic indicator in heart failure. There has been interest in understanding whether pre-operative frailty is associated with worse outcomes after implantation of a left ventricular assist device (LVAD) as destination therapy. Patients undergoing LVAD implantation as destination therapy at the Mayo Clinic, Rochester, Minnesota, from February 2007 to June 2012, were included in this study. Frailty was assessed using the deficit index (31 impairments, disabilities and comorbidities) and defined as the proportion of deficits present. We divided patients based on tertiles of the deficit index (>0.32 = frail, 0.23 to 0.32 = intermediate frail, <0.23 = not frail). Cox proportional hazard regression models were used to examine the association between frailty and death. Patients were censored at death or last follow-up through October 2013. Among 99 patients (mean age 65 years, 18% female, 55% with ischemic heart failure), the deficit index ranged from 0.10 to 0.65 (mean 0.29). After a mean follow-up of 1.9 ± 1.6 years, 79% of the patients had been rehospitalized (range 0 to 17 hospitalizations, median 1 per person) and 45% had died. Compared with those who were not frail, patients who were intermediate frail (adjusted HR 1.70, 95% CI 0.71 to 4.31) and frail (HR 3.08, 95% CI 1.40 to 7.48) were at increased risk for death (p for trend = 0.004). The mean (SD) number of days alive out of hospital the first year after LVAD was 293 (107) for not frail, 266 (134) for intermediate frail and 250 (132) for frail patients. Frailty before destination LVAD implantation is associated with increased risk of death and may represent a significant patient selection consideration. Copyright © 2014 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  11. Detection of premature ventricular contractions on a ventricular electrocardiogram for patients with left ventricular assist devices.

    Science.gov (United States)

    Park, Sung Min; Lee, Jin Hong; Choi, Seong Wook

    2014-12-01

    The ventricular electrocardiogram (v-ECG) was developed for long-term monitoring of heartbeats in patients with a left ventricular assist device (LVAD) and does not normally have the functionality necessary to detect additional heart irregularities that can progress to critical arrhythmias. Although the v-ECG has the benefits of physiological optimization and counterpulsation control, when abnormal heartbeats occur, the v-ECG does not show the distinct abnormal waveform that enables easy detection of an abnormal heartbeat among normal heartbeats on the conventional ECG. In this study, the v-ECGs of normal and abnormal heartbeats are compared with each other with respect to peak-to-peak voltage, area, and maximal slopes, and a new method to detect abnormal heartbeats is suggested. In a series of animal experiments with three porcine models (Yorkshire pigs weighing 30-40 kg), a v-ECG and conventional ECG were taken simultaneously during LVAD perfusion. Clinical experts found 104 abnormal heartbeats from the saved conventional ECG data and confirmed that the other 3159 heartbeats were normal. Almost all of the abnormal heartbeats were premature ventricular contractions (PVCs), and there was short-term tachycardia for 3 s. A personal computer was used to automatically detect abnormal heartbeats with the v-ECG according to the new method, and its results were compared with the clinicians' results. The new method found abnormal heartbeats with 90% accuracy, and less than 15% of the total PVCs were missed. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  12. Costs and reimbursement gaps after implementation of third-generation left ventricular assist devices.

    Science.gov (United States)

    Mishra, Vinod; Geiran, Odd; Fiane, Arnt E; Sørensen, Gro; Andresen, Sølvi; Olsen, Ellen K; Khushi, Ishtiaq; Hagen, Terje P

    2010-01-01

    The purpose of this study was to compare and contrast total hospital costs and subsequent reimbursement of implementing a new program using a third-generation left ventricular assist device (LVAD) in Norway. Between July 2005 and March 2008, the total costs of treatment for 9 patients were examined. Costs were calculated for three periods-the pre-implantation LVAD phase, the LVAD implantation phase and the post-implantation LVAD phase-as well as for total hospital care. Patient-specific costs were obtained prospectively from patient records and included personnel resources, medication, blood products, blood chemistry and microbiology, imaging, and procedure costs including operating room costs. Overhead costs were registered retrospectively and allocated to the specific patient by pre-defined allocation keys. Finally, patient-specific costs and overhead costs were aggregated into total patient costs. The average total patient cost in 2007 U.S. dollars was $735,342 and the median was $613,087 (range $342,581 to $1,256,026). The mean length of stay was 77 days (range 40 to 127 days). For the LVAD implantation phase, the mean cost was $457,795 and median cost was $458,611 (range $246,239 to $677,680). The mean length of stay for the LVAD implantation phase was 55 days (range 25 to 125 days). The diagnosis-related group (DRG) reimbursement (2007) was $143,192. There is significant discrepancy between actual hospital costs and the current Norwegian DRG reimbursement for the LVAD procedure. This discrepancy can be partly explained by excessive costs related to the introduction of a new program with new technology. Costly innovations should be considered in price setting of reimbursement for novel technology. Copyright (c) 2010 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  13. Initial Experience with a Wireless Ultrasound-Guided Vacuum-Assisted Breast Biopsy Device.

    Directory of Open Access Journals (Sweden)

    E-Ryung Choi

    Full Text Available To determine the imaging characteristic of frequent target lesions of wireless ultrasound (US-guided, vacuum-assisted breast biopsy (Wi-UVAB and to evaluate diagnostic yield, accuracy and complication of the device in indeterminate breast lesions.From March 2013 to October 2014, 114 women (age range, 29-76 years; mean age, 50.0 years underwent Wi-UVAB using a 13-gauge needle (Mammotome Elite®; Devicor Medical Products, Cincinnati, OH, USA. In 103 lesions of 96 women with surgical (n = 81 or follow-up (n = 22 data, complications, biopsy procedure, imaging findings of biopsy targets and histologic results were reviewed.Mean number of biopsy cores was 10 (range 4-25. Nine patients developed moderate bleeding. All lesions were suspicious on US, and included non-mass lesions (67.0% and mass lesions (33.0%. Visible calcifications on US were evident in 57.3% of the target lesions. Most of the lesions (93.2% were nonpalpable. Sixty-six (64.1% were malignant [ductal carcinoma in situ (DCIS rate, 61%] and 12 were high-risk lesions (11.7%. Histologic underestimation was identified in 11 of 40 (27.5%. DCIS cases and in 3 of 9 (33.3% high-risk lesions necessitating surgery. There was no false-negative case.Wi-UVAB is very handy and advantageous for US-unapparent non-mass lesions to diagnose DCIS, especially for calcification cases. Histologic underestimation is unavoidable; still, Wi-UVAB is safe and accurate to diagnose a malignancy.

  14. Development of a compact wearable pneumatic drive unit for a ventricular assist device.

    Science.gov (United States)

    Homma, Akihiko; Taenaka, Yoshiyuki; Tatsumi, Eisuke; Akagawa, Eiki; Lee, Hwansung; Nishinaka, Tomohiro; Takewa, Yoshiaki; Mizuno, Toshihide; Tsukiya, Tomonori; Kakuta, Yukihide; Katagiri, Nobumasa; Shimosaki, Isao; Hamada, Shigeru; Mukaibayashi, Hiroshi; Iwaoka, Wataru

    2008-01-01

    The purpose of this study was to develop a compact wearable pneumatic drive unit for a ventricular assist device (VAD). This newly developed drive unit, 20 x 8.5 x 20 cm in size and weighing approximately 1.8 kg, consists of a brushless DC motor, noncircular gears, a crankshaft, a cylinder-piston, and air pressure regulation valves. The driving air pressure is generated by the reciprocating motion of the piston and is controlled by the air pressure regulation valves. The systolic ratio is determined by the noncircular gears, and so is fixed for a given configuration. As a result of an overflow-type mock circulation test, a drive unit with a 44% systolic ratio connected to a Toyobo VAD blood pump with a 70-ml stroke volume achieved a pump output of more than 7 l/min at 100 bpm against a 120 mmHg afterload. Long-term animal tests were also performed using drive units with systolic ratios of 45% and 53% in two Holstein calves weighing 62 kg and 74 kg; the tests were terminated on days 30 and 39, respectively, without any malfunction. The mean aortic pressure, bypass flow, and power consumption for the first calf were maintained at 90 x 13 mmHg, 3.9 x 0.9 l/min, and 12 x 1 W, and those for the second calf were maintained at 88 x 13 mmHg, 5.0 x 0.5 l/min, and 16 x 2 W, respectively. These results indicate that the newly developed drive unit may be used as a wearable pneumatic drive unit for the Toyobo VAD blood pump.

  15. Totally implantable total artificial heart and ventricular assist device with multipurpose miniature electromechanical energy system.

    Science.gov (United States)

    Takatani, S; Orime, Y; Tasai, K; Ohara, Y; Naito, K; Mizuguchi, K; Makinouchi, K; Damm, G; Glueck, J; Ling, J

    1994-01-01

    A multipurpose miniature electromechanical energy system has been developed to yield a compact, efficient, durable, and biocompatible total artificial heart (TAH) and ventricular assist device (VAD). Associated controller-driver electronics were recently miniaturized and converted into hybrid circuits. The hybrid controller consists of a microprocessor and controller, motor driver, Hall sensor, and commutation circuit hybrids. The sizing study demonstrated that all these components can be incorporated in the pumping unit of the TAH and VAD, particularly in the centerpiece of the TAH and the motor housing of the VAD. Both TAH and VAD pumping units will start when their power line is connected to either the internal power pack or the external battery unit. As a redundant driving and diagnostic port, an emergency port was newly added and will be placed in subcutaneous location. In case of system failure, the skin will be cut down, and an external motor drive or a pneumatic driver will be connected to this port to run the TAH. This will minimize the circulatory arrest time. Overall efficiency of the TAH without the transcutaneous energy transmission system was 14-18% to deliver pump outputs of 4-9 L/min against the right and left afterload pressures of 25 and 100 mm Hg. The internal power requirement ranged from 6 to 13 W. The rechargeable batteries such as NiCd or NiMH with 1 AH capacity can run the TAH for 30-45 min. The external power requirement, when TETS efficiency of 75% was assumed, ranged from 8 to 18 W. The accelerated endurance test in the 42 degrees C saline bath demonstrated stable performance over 4 months. Long-term endurance and chronic animal studies will continue toward a system with 5 years durability by the year 2000.

  16. Noninvasive arterial blood pressure waveforms in patients with continuous-flow left ventricular assist devices.

    Science.gov (United States)

    Martina, Jerson R; Westerhof, Berend E; de Jonge, Nicolaas; van Goudoever, Jeroen; Westers, Paul; Chamuleau, Steven; van Dijk, Diederik; Rodermans, Ben F M; de Mol, Bas A J M; Lahpor, Jaap R

    2014-01-01

    Arterial blood pressure and echocardiography may provide useful physiological information regarding cardiac support in patients with continuous-flow left ventricular assist devices (cf-LVADs). We investigated the accuracy and characteristics of noninvasive blood pressure during cf-LVAD support. Noninvasive arterial pressure waveforms were recorded with Nexfin (BMEYE, Amsterdam, The Netherlands). First, these measurements were validated simultaneously with invasive arterial pressures in 29 intensive care unit patients. Next, the association between blood pressure responses and measures derived by echocardiography, including left ventricular end-diastolic dimensions (LVEDDs), left ventricular end-systolic dimensions (LVESDs), and left ventricular shortening fraction (LVSF) were determined during pump speed change procedures in 30 outpatients. Noninvasive arterial blood pressure waveforms by the Nexfin monitor slightly underestimated invasive measures during cf-LVAD support. Differences between noninvasive and invasive measures (mean ± SD) of systolic, diastolic, mean, and pulse pressures were -7.6 ± 5.8, -7.0 ± 5.2, -6.9 ± 5.1, and -0.6 ± 4.5 mm Hg, respectively (all blood pressure responses did not correlate with LVEDD, LVESD, or LVSF, while LVSF correlated weakly with both pulse pressure (r = 0.24; p = 0.005) and (dP(art)/dt)max (r = 0.25; p = 0.004). The dicrotic notch in the pressure waveform was a better predictor of aortic valve opening (area under the curve [AUC] = 0.87) than pulse pressure (AUC = 0.64) and (dP(art)/dt)max (AUC = 0.61). Patients with partial support rather than full support at 9,000 rpm had a significant change in systolic pressure, pulse pressure, and (dP(art)/dt)max during ramp studies, while echocardiographic measures did not change. Blood pressure measurements by Nexfin were reliable and may thereby act as a compliment to the assessment of the cf-LVAD patient.

  17. New monitoring technology to objectively assess adherence to prescribed footwear and assistive devices during ambulatory activity.

    Science.gov (United States)

    Bus, Sicco A; Waaijman, Roelof; Nollet, Frans

    2012-11-01

    To assess the validity and feasibility of a new temperature-based adherence monitor to measure footwear use. Observational study. University medical center and participants' homes. Convenience sample of healthy subjects (n=11) and neuropathic diabetic patients at high risk for foot ulceration (n=14). In healthy subjects, the validity of the in-shoe attached adherence monitor was investigated by comparing its registrations of donning and doffing of footwear during 7 days to an accurately kept log registration. In diabetic patients, the feasibility of using the adherence monitor for 7 days in conjunction with a time-synchronized ankle-worn step activity monitor to register prescribed footwear use during walking was assessed. Furthermore, a usability questionnaire was completed. For validity, the mean time difference and 95% confidence interval (CI) between moments of donning/doffing footwear recorded with the adherence monitor and in the log were calculated. For feasibility, technical performance, usability, and the percentage of steps that the footwear was worn (adherence) were assessed. The mean time difference between the adherence monitor and log recordings was 0.4 minutes (95% CI, 0.2-0.6min). One erroneous recording and 2 incomplete recordings were obtained in diabetic patients. Three patients reported discomfort with the step activity monitor, and 4 patients would not favor repeated testing. Patients used their footwear for between 9% and 99% of their walking steps. The adherence monitor shows good validity in measuring when footwear is used or not, and is, together with instrumented monitoring of walking activity, a feasible and objective method to assess treatment adherence. This method can have wide application in clinical practice and research regarding prescribed footwear and other body-worn assistive devices. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  18. Stereotypes Associated With Age-related Conditions and Assistive Device Use in Canadian Media.

    Science.gov (United States)

    Fraser, Sarah Anne; Kenyon, Virginia; Lagacé, Martine; Wittich, Walter; Southall, Kenneth Edmund

    2016-12-01

    Newspapers are an important source of information. The discourses within the media can influence public attitudes and support or discourage stereotypical portrayals of older individuals. This study critically examined discourses within a Canadian newspaper in terms of stereotypical depictions of age-related health conditions and assistive technology devices (ATDs). Four years (2009-2013) of Globe and Mail articles were searched for terms relevant to the research question. A total of 65 articles were retained, and a critical discourse analysis (CDA) of the texts was conducted. The articles were coded for stereotypes associated with age-related health conditions and ATDs, consequences of the stereotyping, and context (overall setting or background) of the discourse. The primary code list included 4 contexts, 13 stereotypes, and 9 consequences of stereotyping. CDA revealed discourses relating to (a) maintaining autonomy in a stereotypical world, (b) ATDs as obstacles in employment, (c) barriers to help seeking for age-related conditions, and (d) people in power setting the stage for discrimination. Our findings indicate that discourses in the Canadian media include stereotypes associated with age-related health conditions. Further, depictions of health conditions and ATDs may exacerbate existing stereotypes about older individuals, limit the options available to them, lead to a reduction in help seeking, and lower ATD use. Education about the realities of age-related health changes and ATDs is needed in order to diminish stereotypes and encourage ATD uptake and use. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Vacuum-assisted closure device for the management of infected postpneumonectomy chest cavities.

    Science.gov (United States)

    Perentes, Jean Yannis; Abdelnour-Berchtold, Etienne; Blatter, Jeannine; Lovis, Alban; Ris, Hans-Beat; Krueger, Thorsten; Gonzalez, Michel

    2015-03-01

    Infected postpneumonectomy chest cavities may be related to chronic postpneumonectomy empyema or arise in rare situations of necrotizing pneumonia with complete lung destruction where pneumonectomy and pleural debridement are required. We evaluated the safety and efficacy of an intrathoracic vacuum-assisted closure device (VAC) for the treatment of infected postpneumonectomy chest cavities. A retrospective single institution review of all patients with infected postpneumonectomy chest cavities treated by VAC between 2005 and 2013. Patients underwent surgical debridement of the thoracic cavity, muscle flap closure of the bronchial stump when a fistula was present, and repeated intrathoracic VAC dressings until granulation tissue covered the entire chest cavity. After this, the cavity was obliterated by a Clagett procedure and closed. Twenty-one patients (14 men and 7 women) underwent VAC treatment of their infected postpneumonectomy chest cavity. Twelve patients presented with a chronic postpneumonectomy empyema (10 of them with a bronchopleural fistula) and 9 patients with an empyema occurring in the context of necrotizing pneumonia treated by pneumonectomy. In-hospital mortality was 23%. The median duration of VAC therapy was 23 days (range, 4-61 days) and the median number of VAC changes per patient was 6 (range, 2-14 days). Infection control and successful chest cavity closure was achieved in all surviving patients. One adverse VAC treatment-related event was identified (5%). The intrathoracic VAC application is a safe and efficient treatment of infected postpneumonectomy chest cavities and allows the preservation of chest wall integrity. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  20. Is hydrotherapy an appropriate form of exercise for elderly patients with biventricular systolic heart failure?

    Science.gov (United States)

    Sveälv, Bente Grüner; Täng, Margareta Scharin; Cider, Åsa

    2012-01-01

    Hydrotherapy (exercise in warm water) is considered to be a safe and beneficial method to use in the rehabilitation of stable heart failure patients, but there is little information on the effect of the increased venous return and enhanced preload in elderly patients with biventricular heart failure. We present a case of an elderly man who was recruited to participate in a hydrotherapy study. We compared echocardiographic data during warm water immersion with land measurements, and observed increases in stroke volume from 32 mL (land) to 42 mL (water), left ventricular ejection fraction from 22% to 24%, left ventricular systolic velocity from 4.8 cm/s to 5.0 cm/s and left atrioventricular plane displacement from 2.1 mm to 2.2 mm. By contrast, right ventricular systolic velocity decreased from 11.2 cm/s to 8.4 cm/s and right atrioventricular plane displacement from 8.1 mm to 4.7 mm. The tricuspid pressure gradient rose from 18 mmHg on land to 50 mmHg during warm water immersion. Thus, although left ventricular systolic function was relatively unaffected during warm water immersion, we observed a decrease in right ventricular function with an augmented right ventricular pressure. We recommend further investigations to observe the cardiac effect of warm water immersion on patients with biventricular systolic heart failure and at risk of elevated right ventricular pressure. PMID:23341846

  1. Medical devices; exemption from premarket notification; Class II devices; optical impression systems for computer assisted design and manufacturing. Final rule.

    Science.gov (United States)

    2003-04-22

    The Food and Drug Administration (FDA) is publishing an order granting a petition requesting exemption from the premarket notification requirements for data acquisition units for ceramic dental restoration systems. This rule exempts from premarket notification data acquisition units for ceramic dental restoration systems and establishes a guidance document as a special control for this device. FDA is publishing this order in accordance with the Food and Drug Administration Modernization Act of 1997 (FDAMA).

  2. Multicenter Evaluation of Octreotide as Secondary Prophylaxis in Patients With Left Ventricular Assist Devices and Gastrointestinal Bleeding.

    Science.gov (United States)

    Shah, Keyur B; Gunda, Sampath; Emani, Sitaramesh; Kanwar, Manreet K; Uriel, Nir; Colombo, Paolo C; Uber, Patricia A; Sears, Melissa L; Chuang, Joyce; Farrar, David J; Brophy, Donald F; Smallfield, George B

    2017-11-01

    Gastrointestinal (GI) bleeding is one of the most common complications after continuous-flow left ventricular assist device implantation. More than one third of patients with incident bleed go on to develop recurrent GI bleeding. Octreotide, a somatostatin analog, is proposed to reduce the risk of recurrent GI bleeding in this population. This multicenter, retrospective analysis evaluated 51 continuous-flow left ventricular assist device patients who received secondary prophylaxis with octreotide after their index GI bleed from 2009 to 2015. All patients had a hospitalization for GI bleed and received octreotide after discharge. Patient demographics, medical and medication history, and clinical characteristics of patients who rebled after receiving octreotide were compared with non-rebleeders. These data were also compared with matched historical control patients previously enrolled in the HMII (HeartMate II) clinical trials, none of whom received octreotide, to provide a context for the bleeding rates. Twelve patients (24%) who received secondary octreotide prophylaxis developed another GI bleed, whereas 39 (76%) did not. There were similar intergroup demographics; however, significantly more bleeders had a previous GI bleeding history before left ventricular assist device placement (33% versus 5%; P =0.02) and greater frequency of angiodysplasia confirmed during endoscopy (58% versus 23%; P =0.03). Fewer patients in this study experienced a recurrent GI bleed compared with a matched historical control group that did not receive octreotide (24% versus 43%; P =0.04). Patients with continuous-flow left ventricular assist device receiving secondary prophylaxis with octreotide had a significantly lower GI bleed recurrence compared with historical controls not treated with octreotide. Additional prospective studies are needed to confirm these data. © 2017 American Heart Association, Inc.

  3. Design of a Code-Maker Translator Assistive Input Device with a Contest Fuzzy Recognition Algorithm for the Severely Disabled

    Directory of Open Access Journals (Sweden)

    Chung-Min Wu

    2015-01-01

    Full Text Available This study developed an assistive system for the severe physical disabilities, named “code-maker translator assistive input device” which utilizes a contest fuzzy recognition algorithm and Morse codes encoding to provide the keyboard and mouse functions for users to access a standard personal computer, smartphone, and tablet PC. This assistive input device has seven features that are small size, easy installing, modular design, simple maintenance, functionality, very flexible input interface selection, and scalability of system functions, when this device combined with the computer applications software or APP programs. The users with severe physical disabilities can use this device to operate the various functions of computer, smartphone, and tablet PCs, such as sending e-mail, Internet browsing, playing games, and controlling home appliances. A patient with a brain artery malformation participated in this study. The analysis result showed that the subject could make himself familiar with operating of the long/short tone of Morse code in one month. In the future, we hope this system can help more people in need.

  4. Design and Development of a Miniaturized Percutaneously Deployable Wireless Left Ventricular Assist Device: Early Prototypes and Feasibility Testing.

    Science.gov (United States)

    Letzen, Brian; Park, Jiheum; Tuzun, Zeynep; Bonde, Pramod

    The current left ventricular assist devices (LVADs) are limited by a highly invasive implantation procedure in a severely unstable group of advanced heart failure patients. Additionally, the current transcutaneous power drive line acts as a nidus for infection resulting in significant morbidity and mortality. In an effort to decrease this invasiveness and eliminate drive line complications, we have conceived a wireless miniaturized percutaneous LVAD, capable of being delivered endovascularly with a tether-free operation. The system obviates the need for a transcutaneous fluid purge line required in existing temporary devices by utilizing an incorporated magnetically coupled impeller for a complete seal. The objective of this article was to demonstrate early development and proof-of-concept feasibility testing to serve as the groundwork for future formalized device development. Five early prototypes were designed and constructed to iteratively minimize the pump size and improve fluid dynamic performance. Various magnetic coupling configurations were tested. Using SolidWorks and ANSYS software for modeling and simulation, several geometric parameters were varied. HQ curves were constructed from preliminary in vitro testing to characterize the pump performance. Bench top tests showed no-slip magnetic coupling of the impeller to the driveshaft up to the current limit of the motor. The pump power requirements were tested in vitro and were within the appropriate range for powering via a wireless energy transfer system. Our results demonstrate the proof-of-concept feasibility of a novel endovascular cardiac assist device with the potential to eventually offer patients an untethered, minimally invasive support.

  5. [Mechanical circulatory support saves lives -- three years' experience of the newly established assist device program at Semmelweis University, Budapest, Hungary].

    Science.gov (United States)

    Fazekas, Levente; Sax, Balázs; Hartyánszky, István; Pólos, Miklós; Horkay, Ferenc; Varga, Tamás; Rácz, Kristóf; Németh, Endre; Székely, Andrea; Paulovich, Erzsébet; Heltai, Krisztina; Zima, Endre; Szabolcs, Zoltán; Merkely, Béla

    2015-03-29

    Since the celebration of the 20th anniversary of the first heart transplantation in Hungary in 2012 the emerging need for modern heart failure management via mechanical circulatory support has evolved. In May 2012 the opening of a new heart failure and transplant unit with 9 beds together with the procurement of necessary devices at Semmelweis University accomplished this need. The aim of the authors was to report their initial experience obtained in this new cardiac assist device program. Since May, 2012, mechanical circulatory support system was applied in 89 cases in 72 patients. Indication for support were end stage heart failure refractory to medical treatment and acute left or right heart failure. Treatment was initiated for acute graft failure after heart transplantation in 27 cases, for end stage heart failure in 24 cases, for acute myocardial infarction in 21 cases, for acute postcardiotomy heart failure in 14 cases, for severe respiratory insufficiency in 2 cases and for drug intoxication in one case. Among the 30 survivor of the whole program 13 patients were successfully transplanted. The available devices can cover all modalities of current bridge therapy from short term support through medium support to heart transplantation or long term support and destination therapy. These conditions made possible the successful start of a new cardiac assist device program.

  6. Hemodynamic Effects of Ventricular Assist Device Implantation on Norwood, Glenn, and Fontan Circulation: A Simulation Study.

    Science.gov (United States)

    Di Molfetta, Arianna; Amodeo, Antonio; Gagliardi, Maria G; Trivella, Maria G; Fresiello, Libera; Filippelli, Sergio; Toscano, Alessandra; Ferrari, Gianfranco

    2016-01-01

    The growing population of failing single-ventricle (SV) patients might benefit from ventricular assist device (VAD) support as a bridge to heart transplantation. However, the documented experience is limited to isolated case reports. Considering the complex and different physiopathology of Norwood, Glenn, and Fontan patients and the lack of established experience, the aim of this work is to realize and test a lumped parameter model of the cardiovascular system able to simulate SV hemodynamics and VAD implantation effects to support clinical decision. Hemodynamic and echocardiographic data of 30 SV patients (10 Norwood, 10 Glenn, and 10 Fontan) were retrospectively collected and used to simulate patients' baseline. Then, the effects of VAD implantation were simulated. Simulation results suggest that the implantation of VAD: (i) increases the cardiac output and the mean arterial systemic pressure in all the three palliation conditions (Norwood 77.2 and 19.7%, Glenn 38.6 and 32.2%, and Fontan 17.2 and 14.2%); (ii) decreases the SV external work (Norwood 55%, Glenn 35.6%, and Fontan 41%); (iii) decreases the pressure pulsatility index (Norwood 65.2%, Glenn 81.3%, and Fontan 64.8%); (iv) increases the pulmonary arterial pressure in particular in the Norwood circulation (Norwood 39.7%, Glenn 12.1% and Fontan 3%); and (v) decreases the atrial pressure (Norwood 2%, Glenn 10.6%, and Fontan 8.6%). Finally, the VAD work is lower in the Norwood circulation (30.4 mL·mm Hg) in comparison with Fontan (40.3 mL·mm Hg) and to Glenn (64.5 mL·mm Hg) circulations. The use of VAD in SV physiology could be helpful to bridge patients to heart transplantations by increasing the CO and unloading the SV with a decrement of the atrial pressure and the SV external work. The regulation of the pulmonary flow is challenging because the Pap is increased by the presence of VAD. The hemodynamic changes are different in the different SV palliation step. The use of numerical models

  7. Fluid force predictions and experimental measurements for a magnetically levitated pediatric ventricular assist device.

    Science.gov (United States)

    Throckmorton, Amy L; Untaroiu, Alexandrina; Lim, D Scott; Wood, Houston G; Allaire, Paul E

    2007-05-01

    The latest generation of artificial blood pumps incorporates the use of magnetic bearings to levitate the rotating component of the pump, the impeller. A magnetic suspension prevents the rotating impeller from contacting the internal surfaces of the pump and reduces regions of stagnant and high shear flow that surround fluid or mechanical bearings. Applying this third-generation technology, the Virginia Artificial Heart Institute has developed a ventricular assist device (VAD) to support infants and children. In consideration of the suspension design, the axial and radial fluid forces exerted on the rotor of the pediatric VAD were estimated using computational fluid dynamics (CFD) such that fluid perturbations would be counterbalanced. In addition, a prototype was built for experimental measurements of the axial fluid forces and estimations of the radial fluid forces during operation using a blood analog mixture. The axial fluid forces for a centered impeller position were found to range from 0.5 +/- 0.01 to 1 +/- 0.02 N in magnitude for 0.5 +/- 0.095 to 3.5 +/- 0.164 Lpm over rotational speeds of 6110 +/- 0.39 to 8030 +/- 0.57% rpm. The CFD predictions for the axial forces deviated from the experimental data by approximately 8.5% with a maximum difference of 18% at higher flow rates. Similarly for the off-centered impeller conditions, the maximum radial fluid force along the y-axis was found to be -0.57 +/- 0.17 N. The maximum cross-coupling force in the x direction was found to be larger with a maximum value of 0.74 +/- 0.22 N. This resulted in a 25-35% overestimate of the radial fluid force as compared to the CFD predictions; this overestimation will lead to a far more robust magnetic suspension design. The axial and radial forces estimated from the computational results are well within a range over which a compact magnetic suspension can compensate for flow perturbations. This study also serves as an effective and novel design methodology for blood pump

  8. A modified Glenn shunt reduces right ventricular stroke work during left ventricular assist device therapy.

    Science.gov (United States)

    Schiller, Petter; Vikholm, Per; Hellgren, Laila

    2016-03-01

    Right ventricular (RV) failure is a major cause of morbidity and mortality after left ventricular assist device (LVAD) placement and remains hard to predict. We hypothesized that partial surgical exclusion of the RV with a modified Glenn shunt during LVAD treatment would reduce RV stroke work. An LVAD was implanted in eight pigs and a modified Glenn shunt was constructed. A conductance pressure-volume catheter was placed in the right ventricle through the apex. Haemodynamic data and pressure-volume loops were obtained at the following time periods: (i) baseline, (ii) open shunt, (iii) LVAD with closed shunt and (iii) LVAD and open shunt. During LVAD therapy, the right atrial (RA) pressure increased from 9 mmHg (9-9) to 15 mmHg (12-15), P = 0.01. RV stroke volume increased from 30 ml (29-40) to 51 ml (42-53), P work increased to 708 mmHg ml (654-1193) from 535 mmHg ml (424-717), P = 0.04, compared with baseline. During LVAD therapy in combination with a Glenn shunt, the RA pressure decreased from 15 mmHg (12-15) to 10 mmHg (7-11) when compared with LVAD therapy only, P = 0.01. A decrease in RV stroke work from 708 mmHg ml (654-1193) to 465 mmHg ml (366-711), P = 0.04, was seen when the LVAD was combined with a shunt, not significantly different from the baseline value (535 mmHg ml). The developed pressure in the right ventricle decreased from 29 mmHg (26-32) to 21 mmHg (20-24), P work during the use of the shunt with LVAD treatment. A modified Glenn shunt reduced RV volumes, RV stroke work and RA pressure during LVAD therapy in an experimental model of heart failure in pigs. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  9. Risk factors, mortality, and timing of ischemic and hemorrhagic stroke with left ventricular assist devices.

    Science.gov (United States)

    Frontera, Jennifer A; Starling, Randall; Cho, Sung-Min; Nowacki, Amy S; Uchino, Ken; Hussain, M Shazam; Mountis, Maria; Moazami, Nader

    2017-06-01

    Stroke is a major cause of mortality after left ventricular assist device (LVAD) placement. Prospectively collected data of patients with HeartMate II (n = 332) and HeartWare (n = 70) LVADs from October 21, 2004, to May 19, 2015, were reviewed. Predictors of early (during index hospitalization) and late (post-discharge) ischemic and hemorrhagic stroke and association of stroke subtypes with mortality were assessed. Of 402 patients, 83 strokes occurred in 69 patients (17%; 0.14 events per patient-year [EPPY]): early ischemic stroke in 18/402 (4%; 0.03 EPPY), early hemorrhagic stroke in 11/402 (3%; 0.02 EPPY), late ischemic stroke in 25/402 (6%; 0.04 EPPY) and late hemorrhagic stroke in 29/402 (7%; 0.05 EPPY). Risk of stroke and death among patients with stroke was bimodal with highest risks immediately post-implant and increasing again 9-12 months later. Risk of death declined over time in patients without stroke. Modifiable stroke risk factors varied according to timing and stroke type, including tobacco use, bacteremia, pump thrombosis, pump infection, and hypertension (all p hemorrhagic stroke (adjusted odds ratio [aOR] 4.3, 95% confidence interval [CI] 1.0-17.8, p = 0.04), late ischemic stroke (aOR 3.2, 95% CI 1.1-9.0, p = 0.03), and late hemorrhagic stroke (aOR 3.7, 95% CI 1.5-9.2, p = 0.005) predicted death, whereas early ischemic stroke did not. Stroke is a leading cause and predictor of death in patients with LVADs. Risk of stroke and death among patients with stroke is bimodal, with highest risk at time of implant and increasing risk again after 9-12 months. Management of modifiable risk factors may reduce stroke and mortality rates. Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  10. LAPAROSCOPICALLY ASSISTED ANORECTOPLASTY AND THE USE OF THE BIPOLAR DEVICE TO SEAL THE RECTAL URINARY FISTULA.

    Science.gov (United States)

    Dutra, Robson Azevedo; Boscollo, Adriana Cartafina Perez

    2016-01-01

    The anorectal anomalies consist in a complex group of birth defects. Laparoscopic-assisted anorectoplasty improved visualization of the rectal fistula and the ability to place the pull-through segment within the elevator muscle complex with minimal dissection. There is no consensus on how the fistula should be managed. To evaluate the laparoscopic-assisted anorectoplasty and the treatment of the rectal urinary fistula by a bipolar sealing device. It was performed according to the original description by Georgeson1. Was used 10 mm infraumbilical access portal for 30º optics. The pneumoperitoneum was established with pressure 8-10 cm H2O. Two additional trocars of 5 mm were placed on the right and left of the umbilicus. The dissection started on peritoneal reflection using Ligasure(r). With the reduction in the diameter of the distal rectum was identified the fistula to the urinary tract. The location of the new anus was defined by the location of the external anal sphincter muscle complex, using electro muscle stimulator externally. Finally, it was made an anastomosis between the rectum and the new location of the anus. A Foley urethral probe was left for seven days. Seven males were operated, six with rectoprostatic and one with rectovesical fistula. The follow-up period ranged from one to four years. The last two patients operated underwent bipolar sealing of the fistula between the rectum and urethra without sutures or surgical ligation. No evidence of urethral leaks was identified. There are benefits of the laparoscopic-assisted anorectoplasty for the treatment of anorectal anomaly. The use of a bipolar energy source that seals the rectal urinary fistula has provided a significant decrease in the operating time and made the procedure be more elegant. As anomalias anorretais consistem de um grupo complexo de defeitos congênitos. A anorretoplastia laparoscópica permite melhor visualização da fístula retourinária e propicia o posicionamento do reto abaixado

  11. Assistive Devices for People with Hearing, Voice, Speech, or Language Disorders

    Science.gov (United States)

    ... the person with hearing loss. With today’s new electronic communication devices, however, TTY machines have almost become a thing of the past. People can place phone calls through the telecommunications relay service using almost any device with a keypad, ...

  12. Substrate type < 111 >-Cu{sub 2}O/<0001 >-ZnO photovoltaic device prepared by photo-assisted electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Zamzuri, Mohd, E-mail: zamzuri@tf.me.tut.ac.jp [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); School of Manufacturing Eng., Universiti Malaysia Perlis, Kampus Tetap Pauh Putra, Jln Arau-Changlun, 02600 Arau, Perlis (Malaysia); Sasano, Junji [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Mohamad, Fariza Binti [Faculty of Electrical & Electronic Eng., University Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor (Malaysia); Izaki, Masanobu [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan)

    2015-11-30

    The substrate-type < 0001 > ZnO/<111 > Cu{sub 2}O photovoltaic (PV) device has been constructed by electrodeposition of a < 111 >-p-Cu{sub 2}O layer on an Au(111)/Si wafer substrate followed by stacking the n-ZnO layer by electrodeposition during light irradiation in aqueous solutions. The PV device was fabricated by stacking the Al:ZnO-window by sputtering and the top Al electrode by vacuum evaporation. The < 0001 >-ZnO layer was composed of aggregates of hexagonal columnar grains grown in the direction normal to the surface, and pores could be observed between the ZnO grains at the deposition time last 1800 s. The < 0001 >-ZnO/<111 >-Cu{sub 2}O PV device showed a photovoltaic performance under AM1.5 illumination, and showed the improved short-circuit current density of 5.87 mA cm{sup −2} by stacking the AZO-TCO due to the increase in the diffusion length of the carrier. - Highlights: • Substrate type ZnO/Cu{sub 2}O photovoltaic devices only by electrodeposition • ZnO layer was stacked on the Cu{sub 2}O layer by photo-assisted electrodeposition. • AZO/ZnO/Cu{sub 2}O photovoltaic devices with a short-circuit current density of 5.87 mA cm{sup −2}.

  13. Assessing symmetry using the mirror stand device with manual and software-assisted methods in postoperative zygomatic fracture patients

    Science.gov (United States)

    Syarif, A. N.; Bangun, K.

    2017-08-01

    Zygomatic fractures are among the most common fractures to the facial skeleton. However, because no standard and reliable method of evaluation is available to assess postoperative patients, we often rely on photographs and subjective assessments. A portable mirror stand device (MiRS), which is a new method for the standardization of photography, was developed in our institution. Used with image analysis software, this device provides a new method for evaluating outcomes after the open reduction and internal fixation of zygomatic fractures. The portable mirror stand device was set up in our outpatient clinic at the Cleft Craniofacial Center at Cipto Mangunkusumo Hospital. Photographs of 11 postoperative patients were taken using the device, and they were analyzed both manually and using image analysis software (ImageJ 1.46) for symmetry. The two methods were then compared to assess the correlation and agreement of the results. The measurements taken using the manual method and the software-assisted method did not differ significantly, which indicated the good agreement between the two methods. The results of the symmetry achieved atour center were similar to other centers in the Asian region (ΔZy = 3.4±1.5 mm, ΔBc = 2.6±1.6 mm, ΔCh = 2.3±2.4 mm) compared with (ΔZy = 3.2±1.7 mm, ΔBc = 2.6±1.6 mm, ΔCh = 2.3±2.5 mm). The treatment of zygomatic fracture a tour center achieved good results. The portable mirror stand device assisted the image analysis software (ImageJ 1.46), which could be beneficial in assessing symmetry in postoperative zygomatic fracture patients.

  14. Biventricular Noncompaction Cardiomyopathy in a Patient Presenting with New Onset Seizure: Case Report

    Directory of Open Access Journals (Sweden)

    Oghenerukevwe Odiete

    2012-01-01

    Full Text Available Ventricular noncompaction (VNC of the myocardium is a rare genetic cardiomyopathy caused by a disorder during endocardial morphogenesis and could be accompanied by life-threatening complications. The major clinical manifestations of VNC are heart failure, arrhythmias, and embolic events. The left ventricle is the most commonly reported affected site, but a few cases of right ventricular involvement have also been reported. We report a case of biventricular noncompaction cardiomyopathy in a 31-year-old woman presenting with a new onset seizure. On the second day of her telemetry-monitored hospitalization, she suffered a witnessed ventricular fibrillation arrest requiring emergency direct-current cardioversion and induced hypothermia. Transthoracic echocardiography (TTE showed isolated left ventricular (LV noncompaction and depressed LV systolic function. Subsequent cardiac magnetic resonance imaging (MRI revealed both left and right ventricular noncompaction. This unusual presentation highlights the importance of a complete and thorough evaluation of patients even when presenting with apparently noncardiac symptom(s.

  15. Soft robotic devices for hand rehabilitation and assistance: a narrative review.

    Science.gov (United States)

    Chu, Chia-Ye; Patterson, Rita M

    2018-02-17

    The debilitating effects on hand function from a number of a neurologic disorders has given rise to the development of rehabilitative robotic devices aimed at restoring hand function in these patients. To combat the shortcomings of previous traditional robotics, soft robotics are rapidly emerging as an alternative due to their inherent safety, less complex designs, and increased potential for portability and efficacy. While several groups have begun designing devices, there are few devices that have progressed enough to provide clinical evidence of their design's therapeutic abilities. Therefore, a global review of devices that have been previously attempted could facilitate the development of new and improved devices in the next step towards obtaining clinical proof of the rehabilitative effects of soft robotics in hand dysfunction. A literature search was performed in SportDiscus, Pubmed, Scopus, and Web of Science for articles related to the design of soft robotic devices for hand rehabilitation. A framework of the key design elements of the devices was developed to ease the comparison of the various approaches to building them. This framework includes an analysis of the trends in portability, safety features, user intent detection methods, actuation systems, total DOF, number of independent actuators, device weight, evaluation metrics, and modes of rehabilitation. In this study, a total of 62 articles representing 44 unique devices were identified and summarized according to the framework we developed to compare different design aspects. By far, the most common type of device was that which used a pneumatic actuator to guide finger flexion/extension. However, the remainder of our framework elements yielded more heterogeneous results. Consequently, those results are summarized and the advantages and disadvantages of many design choices as well as their rationales were highlighted. The past 3 years has seen a rapid increase in the development of soft robotic

  16. Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

    Directory of Open Access Journals (Sweden)

    Khayat Andre

    2011-01-01

    Full Text Available Abstract We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

  17. The pharmacotherapy of the HeartMate II, a continuous flow left ventricular assist device, in patients with advanced heart failure: integration of disease, device, and drug.

    Science.gov (United States)

    Jennings, Douglas L; Chambers, Rachel M; Schillig, Jessica M

    2010-10-01

    Advanced heart failure continues to be a significant cause of morbidity and mortality in the US. Patients with advanced heart failure have a poor prognosis without cardiac transplantation. The use of left ventricular assist devices (LVADs) as destination therapy for these patients is therefore expected to increase in the coming years as technology advances. The HeartMate II, a continuous flow implantable device, is currently the only LVAD that has been approved by the Food and Drug Administration for destination therapy in patients with advanced heart failure. The pharmacotherapy associated with this device is very complex and, therefore, the need for expertly trained clinical pharmacists to care for this expanding patient population will also likely increase. Unfortunately, most pharmacists are unfamiliar with the effect of LVADs on the physiology and pharmacotherapy of a patient's heart failure. The purpose of this article is to give clinical pharmacists an introduction to the most common pharmacotherapeutic issues for patients with LVADs and present practical solutions for managing common drug therapy problems.

  18. First pediatric transatlantic air ambulance transportation on a Berlin Heart EXCOR left ventricular assist device as a bridge to transplantation.

    Science.gov (United States)

    Tissot, Cecile; Buchholz, Holger; Mitchell, Max B; da Cruz, Eduardo; Miyamoto, Shelley D; Pietra, Bill A; Charpentier, Arnaud; Ghez, Olivier

    2010-03-01

    Mechanical circulatory devices are indicated in patients with refractory cardiac failure as a bridge to recovery or to transplantation. Whenever required, transportation while on mechanical support is a challenge and still limited by technical restrictions or distance. We report the first pediatric case of transatlantic air transportation on a Berlin Heart EXCOR ventricular assist device (Berlin Heart, Berlin, Germany) of a 13-yr-old American female who presented in cardiogenic shock with severe systolic dysfunction while vacationing in France. Rapid hemodynamic deterioration occurred despite maximal medical treatment, and she was supported initially with extracorporeal membrane oxygenation converted to a Berlin Heart EXCOR left ventricular assist device. Long-distance air transportation of the patient was accomplished 3 wks after implantation from Marseille, France, to Denver, Colorado. No adverse hemodynamic effects were encountered during the 13.5-hr flight (8770 km). The patient did not recover sufficient cardiac function and underwent successful orthotopic heart transplantation 3 months after the initial event. Our experience suggests that long-distance air transportation of pediatric patients using the Berlin Heart EXCOR mobile unit as a bridge to recovery or transplantation is feasible and appears safe.

  19. Quality of Life, Depression, and Anxiety in Ventricular Assist Device Therapy: Longitudinal Outcomes for Patients and Family Caregivers.

    Science.gov (United States)

    Bidwell, Julie T; Lyons, Karen S; Mudd, James O; Gelow, Jill M; Chien, Christopher V; Hiatt, Shirin O; Grady, Kathleen L; Lee, Christopher S

    Patients who receive ventricular assist device (VAD) therapy typically rely on informal caregivers (family members or friends) to assist them in managing their device. The purpose of this study is to characterize changes in person-oriented outcomes (quality of life [QOL], depression, and anxiety) for VAD patients and their caregivers together from pre-implantation to 3 months post-implantation. This was a formal interim analysis from an ongoing prospective study of VAD patients and caregivers (n = 41 dyads). Data on person-oriented outcomes (QOL: EuroQol 5 Dimensions Visual Analog Scale; depression: Patient Health Questionnaire-8; anxiety: Brief Symptom Inventory) were collected at 3 time points (just prior to implantation and at 1 and 3 months post-implantation). Trajectories of change for patients and caregivers on each measure were estimated using latent growth modeling with parallel processes. Patients' QOL improved significantly over time, whereas caregiver QOL worsened. Depression and anxiety also improved significantly among patients but did not change among caregivers. There was substantial variability in change on all outcomes for both patients and their caregivers. This is the first quantitative study of VAD patient-caregiver dyads in modern devices that describes change in person-oriented outcomes from pre-implantation to post-implantation. This work supports the need for future studies that account for the inherent relationships between patient and caregiver outcomes and examine variability in patient and caregiver responses to VAD therapy.

  20. Benefit of warm water immersion on biventricular function in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Kardassis Dimitris

    2009-07-01

    Full Text Available Abstract Background Regular physical activity and exercise are well-known cardiovascular protective factors. Many elderly patients with heart failure find it difficult to exercise on land, and hydrotherapy (training in warm water could be a more appropriate form of exercise for such patients. However, concerns have been raised about its safety. The aim of this study was to investigate, with echocardiography and Doppler, the acute effect of warm water immersion (WWI and effect of 8 weeks of hydrotherapy on biventricular function, volumes and systemic vascular resistance. A secondary aim was to observe the effect of hydrotherapy on brain natriuretic peptide (BNP. Methods Eighteen patients [age 69 ± 8 years, left ventricular ejection fraction 31 ± 9%, peakVO2 14.6 ± 4.5 mL/kg/min] were examined with echocardiography on land and in warm water (34°C. Twelve of these patients completed 8 weeks of control period followed by 8 weeks of hydrotherapy twice weekly. Results During acute WWI, cardiac output increased from 3.1 ± 0.8 to 4.2 ± 0.9 L/min, LV tissue velocity time integral from 1.2 ± 0.4 to 1.7 ± 0.5 cm and right ventricular tissue velocity time integral from 1.6 ± 0.6 to 2.5 ± 0.8 cm (land vs WWI, p There was no change in the cardiovascular response or BNP after 8 weeks of hydrotherapy. Conclusion Hydrotherapy was well tolerated by all patients. The main observed cardiac effect during acute WWI was a reduction in heart rate, which, together with a decrease in afterload, resulted in increases in systolic and diastolic biventricular function. Although 8 weeks of hydrotherapy did not improve cardiac function, our data support the concept that exercise in warm water is an acceptable regime for patients with heart failure.

  1. Liquid phase solvent bonding of plastic microfluidic devices assisted by retention grooves.

    Science.gov (United States)

    Wan, Alwin M D; Sadri, Amir; Young, Edmond W K

    2015-01-01

    We report a novel method for achieving consistent liquid phase solvent bonding of plastic microfluidic devices via the use of retention grooves at the bonding interface. The grooves are patterned during the regular microfabrication process, and can be placed at the periphery of a device, or surrounding microfluidic features with open ports, where they effectively mitigate solvent evaporation, and thus substantially reduce poor bond coverage. This method is broadly applicable to a variety of plastics and solvents, and produces devices with high bond quality (i.e., coverage, strength, and microfeature fidelity) that are suitable for studies in physics, chemistry, and cell biology at the microscale.

  2. Laser-Assisted Simultaneous Transfer and Patterning of Vertically Aligned Carbon Nanotube Arrays on Polymer Substrates for Flexible Devices

    KAUST Repository

    In, Jung Bin

    2012-09-25

    We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet in contact with one another. The absorbed laser heat promotes nanotube adhesion to the polymer in the irradiated regions and enables selective pattern transfer. A combination of the thermal transfer mechanism with rapid direct writing capability of focused laser beam irradiation allows us to achieve simultaneous material transfer and direct micropatterning in a single processing step. Furthermore, we demonstrate that malleability of the nanotube arrays transferred onto a flexible substrate enables post-transfer tailoring of electric conductance by collapsing the aligned nanotubes in different directions. This work suggests that the laser-assisted transfer technique provides an efficient route to using vertically aligned nanotubes as conductive elements in flexible device applications. © 2012 American Chemical Society.

  3. Laser-assisted simultaneous transfer and patterning of vertically aligned carbon nanotube arrays on polymer substrates for flexible devices.

    Science.gov (United States)

    In, Jung Bin; Lee, Daeho; Fornasiero, Francesco; Noy, Aleksandr; Grigoropoulos, Costas P

    2012-09-25

    We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet in contact with one another. The absorbed laser heat promotes nanotube adhesion to the polymer in the irradiated regions and enables selective pattern transfer. A combination of the thermal transfer mechanism with rapid direct writing capability of focused laser beam irradiation allows us to achieve simultaneous material transfer and direct micropatterning in a single processing step. Furthermore, we demonstrate that malleability of the nanotube arrays transferred onto a flexible substrate enables post-transfer tailoring of electric conductance by collapsing the aligned nanotubes in different directions. This work suggests that the laser-assisted transfer technique provides an efficient route to using vertically aligned nanotubes as conductive elements in flexible device applications.

  4. Development and control of a magnetorheological haptic device for robot assisted surgery.

    Science.gov (United States)

    Shokrollahi, Elnaz; Goldenberg, Andrew A; Drake, James M; Eastwood, Kyle W; Kang, Matthew

    2017-07-01

    A prototype magnetorheological (MR) fluid-based actuator has been designed for tele-robotic surgical applications. This device is capable of generating forces up to 47 N, with input currents ranging from 0 to 1.5 A. We begin by outlining the physical design of the device, and then discuss a novel nonlinear model of the device's behavior. The model was developed using the Hammerstein-Wiener (H-W) nonlinear black-box technique and is intended to accurately capture the hysteresis behavior of the MR-fluid. Several experiments were conducted on the device to collect estimation and validation datasets to construct the model and assess its performance. Different estimating functions were used to construct the model, and their effectiveness is assessed based on goodness-of-fit and final-prediction-error measurements. A sigmoid network was found to have a goodness-of-fit of 95%. The model estimate was then used to tune a PID controller. Two control schemes were proposed to eliminate the hysteresis behavior present in the MR fluid device. One method uses a traditional force feedback control loop and the other is based on measuring the magnetic field using a Hall-effect sensor embedded within the device. The Hall-effect sensor scheme was found to be superior in terms of cost, simplicity and real-time control performance compared to the force control strategy.

  5. The Effect of the Usage of Computer-Based Assistive Devices on the Functioning and Quality of Life of Individuals Who Are Blind or Have Low Vision

    Science.gov (United States)

    Rosner, Yotam; Perlman, Amotz

    2018-01-01

    Introduction: The Israel Ministry of Social Affairs and Social Services subsidizes computer-based assistive devices for individuals with visual impairments (that is, those who are blind or have low vision) to assist these individuals in their interactions with computers and thus to enhance their independence and quality of life. The aim of this…

  6. Ramp Study Hemodynamics, Functional Capacity, and Outcome in Heart Failure Patients with Continuous-Flow Left Ventricular Assist Devices

    DEFF Research Database (Denmark)

    Jung, Mette H; Gustafsson, Finn; Houston, Brian

    2016-01-01

    Ramp studies-measuring changes in cardiac parameters as a function of serial pump speed changes (revolutions per minute [rpm])-are increasingly used to evaluate function and malfunction of continuous-flow left ventricular assist devices (CF-LVADs). We hypothesized that ramp studies can predict...... patients (HeartMate II, Thoratec Corporation, Pleasanton, CA). Functional status was evaluated in 70% (31/44); average 6 minute walk test (6MWT) was 312 ± 220 min, New York Heart Association (NYHA) I-II/III-IV (70/30%) and activity scores very low-low/moderate-very high (55/45%). Decrease in pulmonary...

  7. Fluoroscopy-Guided Resolution of Ingested Thrombus Leading to Functional Disturbance of a Continuous-Flow Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Jens Garbade

    2012-01-01

    Full Text Available The third generation of left ventricular assist devices (LVADs has been shown to improve outcome and quality of life in patients suffering from acute and chronic heart failure. However, VAD-associated complications are still a challenge in the clinical practice. Here we report the resolution of a mobile thrombus formation in the proximity of the inflow cannula of a third generation of LVADs (HVAD Pump, HeartWare, Inc. in a patient with chronic heart failure 4 months after implantation.

  8. Electronic and optical device applications of hollow cathode plasma assisted atomic layer deposition based GaN thin films

    International Nuclear Information System (INIS)

    Bolat, Sami; Tekcan, Burak; Ozgit-Akgun, Cagla; Biyikli, Necmi; Okyay, Ali Kemal

    2015-01-01

    Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metal–semiconductor–metal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) are demonstrated. Resistivity of GaN thin films and metal-GaN contact resistance are investigated as a function of annealing temperature. Effect of the plasma gas and postmetallization annealing on the performances of the TFTs as well as the effect of the annealing on the performance of MSM photodetectors are studied. Dark current to voltage and responsivity behavior of MSM devices are investigated as well. TFTs with the N 2 /H 2 PA-ALD based GaN channels are observed to have improved stability and transfer characteristics with respect to NH 3 PA-ALD based transistors. Dark current of the MSM photodetectors is suppressed strongly after high-temperature annealing in N 2 :H 2 ambient

  9. Structural and composition investigations at delayered locations of low k integrated circuit device by gas-assisted focused ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dandan, E-mail: dandan.wang@globalfoundries.com; Kee Tan, Pik; Yamin Huang, Maggie; Lam, Jeffrey; Mai, Zhihong [Technology Development Department, GLOBALFOUNDRIES Singapore Pte. Ltd., 60 Woodlands Industrial Park D, Street 2, Singapore 738406 (Singapore)

    2014-05-15

    The authors report a new delayering technique – gas-assisted focused ion beam (FIB) method and its effects on the top layer materials of integrated circuit (IC) device. It demonstrates a highly efficient failure analysis with investigations on the precise location. After removing the dielectric layers under the bombardment of an ion beam, the chemical composition of the top layer was altered with the reduced oxygen content. Further energy-dispersive x-ray spectroscopy and Fourier transform infrared analysis revealed that the oxygen reduction lead to appreciable silicon suboxide formation. Our findings with structural and composition alteration of dielectric layer after FIB delayering open up a new insight avenue for the failure analysis in IC devices.

  10. Provision of assistive technology devices among people with ALS in Germany: a platform-case management approach.

    Science.gov (United States)

    Funke, Andreas; Spittel, Susanne; Grehl, Torsten; Grosskreutz, Julian; Kettemann, Dagmar; Petri, Susanne; Weyen, Ute; Weydt, Patrick; Dorst, Johannes; Ludolph, Albert C; Baum, Petra; Oberstadt, Moritz; Jordan, Berit; Hermann, Andreas; Wolf, Joachim; Boentert, Matthias; Walter, Bertram; Gajewski, Nadine; Maier, André; Münch, Christoph; Meyer, Thomas

    2018-01-30

    The procurement of assistive technology devices (ATD) is an essential component of managed care in ALS. The objective was to analyze the standards of care for ATD and to identify challenges in the provision process. A cohort study design was used. We investigated the provision of 11,364 ATD in 1494 patients with ALS at 12 ALS centers in Germany over four years. Participants were patients that entered a case management program for ATD including systematic assessment of ATD on a digital management platform. Wheelchairs (requested in 65% of patients), orthoses (52%), bathroom adaptations (49%), and communication devices (46%) were the most needed ATD. There was a wide range in the number of indicated ATD per patient: 1 to 4 ATD per patient in 45% of patients, 5 to 20 ATD in 48%, and >20 ATD in 7% of patients. Seventy percent of all requested ATD were effectively delivered. However, an alarming failure rate during procurement was found in ATD that are crucial for ALS patients such as powered wheelchairs (52%), communication devices (39%), or orthoses (21%). Leading causes for not providing ATD were the refusal by health insurances, the decision by patients, and the death of the patient before delivery of the device. The need for ATD was highly prevalent among ALS patients. Failed or protracted provision posed substantial barriers to ATD procurement. Targeted national strategies and the incorporation of ATD indication criteria in international ALS treatment guidelines are urgently needed to overcome these barriers.

  11. Toxicity testing of human assisted reproduction devices using the mouse embryo assay.

    NARCIS (Netherlands)

    Punt-Van der Zalm, J.P.; Hendriks, J.C.M.; Westphal, J.R.; Kremer, J.A.M.; Teerenstra, S.; Wetzels, A.M.M.

    2009-01-01

    Systems to assess the toxicity of materials used in human assisted reproduction currently lack efficiency and/or sufficient discriminatory power. The development of 1-cell CBA/B6 F1 hybrid mouse embryos to blastocysts, expressed as blastocyst rate (BR), is used to measure toxicity. The embryos were

  12. A novel vacuum assisted closure therapy model for use with percutaneous devices.

    Science.gov (United States)

    Cook, Saranne J; Nichols, Francesca R; Brunker, Lucille B; Bachus, Kent N

    2014-06-01

    Long-term maintenance of a dermal barrier around a percutaneous prosthetic device remains a common clinical problem. A technique known as Negative Pressure Wound Therapy (NPWT) uses negative pressure to facilitate healing of impaired and complex soft tissue wounds. However, the combination of using negative pressure with percutaneous prosthetic devices has not been investigated. The goal of this study was to develop a methodology to apply negative pressure to the tissues surrounding a percutaneous device in an animal model; no tissue healing outcomes are presented. Specifically, four hairless rats received percutaneous porous coated titanium devices implanted on the dorsum and were bandaged with a semi occlusive film dressing. Two of these animals received NPWT; two animals received no NPWT and served as baseline controls. Over a 28-day period, both the number of dressing changes required between the two groups as well as the pressures were monitored. Negative pressures were successfully applied to the periprosthetic tissues in a clinically relevant range with a manageable number of dressing changes. This study provides a method for establishing, maintaining, and quantifying controlled negative pressures to the tissues surrounding percutaneous devices using a small animal model. Published by Elsevier Ltd.

  13. Engineered embodiment: Comment on "The embodiment of assistive devices-from wheelchair to exoskeleton" by M. Pazzaglia and M. Molinari

    Science.gov (United States)

    Kannape, Oliver Alan; Lenggenhager, Bigna

    2016-03-01

    From brain-computer interfaces to wearable robotics and bionic prostheses - intelligent assistive devices have already become indispensable in the therapy of people living with reduced sensorimotor functioning of their physical body, be it due to spinal cord injury, amputation or brain lesions [1]. Rapid technological advances will continue to fuel this field for years to come. As Pazzaglia and Molinari [2] rightly point out, progress in this domain should not solely be driven by engineering prowess, but utilize the increasing psychological and neuroscientific understanding of cortical body-representations and their plasticity [3]. We argue that a core concept for such an integrated embodiment framework was introduced with the formalization of the forward model for sensorimotor control [4]. The application of engineering concepts to human movement control paved the way for rigorous computational and neuroscientific analysis. The forward model has successfully been adapted to investigate principles underlying aspects of bodily awareness such as the sense of agency in the comparator framework [5]. At the example of recent advances in lower limb prostheses, we propose a cross-disciplinary, integrated embodiment framework to investigate the sense of agency and the related sense of body ownership for such devices. The main onus now is on the engineers and cognitive scientists to embed such an approach into the design of assistive technology and its evaluation battery.

  14. Impact of tricuspid valve surgery at the time of left ventricular assist device insertion on postoperative outcomes.

    Science.gov (United States)

    Dunlay, Shannon M; Deo, Salil V; Park, Soon J

    2015-01-01

    Tricuspid regurgitation (TR) is common in patients with heart failure undergoing left ventricular assist device (LVAD) implantation. Whether the TR should be surgically managed at the time of LVAD surgery is controversial. We searched SCOPUS, Web of Science, Ovid EMBASE, and Ovid MEDLINE (through May 10, 2014) for randomized controlled trials and observational studies comparing postoperative outcomes in patients treated with LVAD with concomitant tricuspid valve surgery (TVS) compared with LVAD alone. Six observational studies including 3,249 patients compared outcomes following LVAD + TVS versus LVAD. Four studies were single-center and most did not adjust for potential confounders. Addition of TVS prolonged cardiopulmonary bypass times by an average of 31 minutes (three studies, 95% CI 20-42). There was no difference in need for right ventricular assist device (six studies, HR 1.42, 95% CI 0.54-3.76), acute renal failure (four studies, HR 1.07, 95% CI 0.55-2.10), or early mortality (six studies, HR 1.28, 95% CI 0.78-2.08) in patients treated with LVAD + TVS versus LVAD alone. TVS prolongs cardiopulmonary bypass times, but available data demonstrate no significant association with early postoperative outcomes. However, differences in baseline risk of patients treated with TVS versus not limit our ability to draw conclusions.

  15. Risk Stratification of Patients With Current Generation Continuous-Flow Left Ventricular Assist Devices Being Bridged to Heart Transplantation.

    Science.gov (United States)

    Guha, Ashrith; Nguyen, Duc; Cruz-Solbes, Ana S; Amione-Guerra, Javier; Schutt, Robert C; Bhimaraj, Arvind; Trachtenberg, Barry H; Park, Myung H; Graviss, Edward A; Gaber, Osama; Suarez, Erik; Montane, Eva; Torre-Amione, Guillermo; Estep, Jerry D

    Patients bridged to transplant (BTT) with continuous-flow left ventricular assist devices (CF-LVADs) have increased in the past decade. Decision support tools for these patients are limited. We developed a risk score to estimate prognosis and guide decision-making. We included heart transplant recipients bridged with CF-LVADs from the United Network for Organ Sharing (UNOS) database and divided them into development (2,522 patients) and validation cohorts (1,681 patients). Univariate and multivariate Cox proportional hazards models were performed. Variables that independently predicted outcomes (age, African American race, recipient body mass index [BMI], intravenous [IV] antibiotic use, pretransplant dialysis, and total bilirubin) were assigned weight using linear transformation, and risk scores were derived. Patients were grouped by predicted posttransplant mortality: low risk (≤ 38 points), medium risk (38-41 points), and high risk (≥ 42 points). We performed Cox proportional hazards analysis on wait-listed CF-LVAD patients who were not transplanted. Score significantly discriminated survival among the groups in the development cohort (6.7, 12.9, 20.7; p = 0.001), validation cohort (6.4, 10.1, 13.6; p assist device (LVAD) BTT risk score that effectively identifies CF-LVAD patients who are at higher risk for worse outcomes after heart transplant. This score may help physicians weigh the risks of transplantation in patients with CF-LVAD.

  16. The NHLBI REVIVE-IT study: Understanding its discontinuation in the context of current left ventricular assist device therapy.

    Science.gov (United States)

    Pagani, Francis D; Aaronson, Keith D; Kormos, Robert; Mann, Douglas L; Spino, Cathie; Jeffries, Neal; Taddei-Peters, Wendy C; Mancini, Donna M; McNamara, Dennis M; Grady, Kathleen L; Gorcsan, John; Petrucci, Ralph; Anderson, Allen S; Glick, Henry A; Acker, Michael A; Eduardo Rame, J; Goldstein, Daniel J; Pamboukian, Salpy V; Miller, Marissa A; Timothy Baldwin, J

    2016-11-01

    The National Institutes of Health National Heart, Lung, and Blood Institute convened a working group in March 2008 to discuss how therapies for heart failure (HF) might be best advanced using clinical trials involving left ventricular assist devices (LVAD). This group opined that the field was ready for a trial to assess the use of long-term ventricular assist device therapy in patients who are less ill than patients currently eligible for destination therapy, which resulted in the Randomized Evaluation of VAD InterVEntion before Inotropic Therapy (REVIVE-IT) pilot study. The specific objective of REVIVE-IT was to compare LVAD therapy with optimal medical management in patients with less advanced HF than current LVAD indications to determine if wider application of permanent LVAD use to less ill patients would be associated with improved survival, quality of life, or functional capacity. REVIVE-IT represented an extraordinary effort to provide data from a randomized clinical trial to inform clinicians, scientists, industry, and regulatory agencies about the efficacy and safety of LVAD therapy in a population with less advanced HF. Despite significant support from the medical community, industry, and governmental agencies, REVIVE-IT failed to accomplish its goal. The reasons for its failure are instructive, and the lessons learned from the REVIVE-IT experience are likely to be relevant to any future study of LVAD therapy in a population with less advanced HF. Copyright © 2016 International Society for Heart and Lung Transplantation. All rights reserved.

  17. Enabling GPU-assisted Antivirus Protection on Android Devices Through Edge Offloading

    DEFF Research Database (Denmark)

    Deyannis, Dimitris; Tsirbas, Rafail; Vasiliadis, Giorgos

    2018-01-01

    Antivirus software are the most popular tools for detecting and stopping malicious or unwanted files. However, the performance requirements of traditional host-based antivirus make their wide adoption to mobile, embedded, and hand-held devices questionable. Their computational- and memory...

  18. Advanced laser-based tracking device for motor vehicle lane position monitoring and steering assistance

    Science.gov (United States)

    Bachalo, William D.; Inenaga, Andrew; Schuler, Carlos A.

    1995-12-01

    Aerometrics is developing an innovative laser-diode based device that provides a warning signal when a motor-vehicle deviates from the center of the lane. The device is based on a sensor that scans the roadway on either side of the vehicle and determines the lateral position relative to the existing painted lines marking the lane. No additional markings are required. A warning is used to alert the driver of excessive weaving or unanticipated departure from the center of the lane. The laser beams are at invisible wavelengths to that operation of the device does not pose a distraction to the driver or other motorists: When appropriate markers are not present on the road, the device is capable of detecting this condition and warn the driver. The sensor system is expected to work well irrespective of ambient light levels, fog and rain. This sensor has enormous commercial potential. It could be marketed as an instrument to warn drivers that they are weaving, used as a research tool to monitor driving patterns, be required equipment for those previously convicted of driving under the influence, or used as a backup sensor for vehicle lateral position control. It can also be used in storage plants to guide robotic delivery vehicles. In this paper, the principles of operation of the sensor, and the results of Aerometrics ongoing testing will be presented.

  19. Splenectomy revised: manually assisted splenectomy with the dexterity device--a feasibility study in 22 patients

    NARCIS (Netherlands)

    Meijer, D. W.; Gossot, D.; Jakimowicz, J. J.; de Wit, L. T.; Bannenberg, J. J.; Gouma, D. J.

    1999-01-01

    Laparoscopic splenectomy claims a number of advantages over open surgery: less trauma, quicker recovery, and faster return to normal activity. On the other hand, laparoscopic splenectomy is complex and time consuming, and so far, many surgeons are reluctant to perform such an operation. A new device

  20. Real-Time Mobile Device-Assisted Chest Compression During Cardiopulmonary Resuscitation.

    Science.gov (United States)

    Sarma, Satyam; Bucuti, Hakiza; Chitnis, Anurag; Klacman, Alex; Dantu, Ram

    2017-07-15

    Prompt administration of high-quality cardiopulmonary resuscitation (CPR) is a key determinant of survival from cardiac arrest. Strategies to improve CPR quality at point of care could improve resuscitation outcomes. We tested whether a low cost and scalable mobile phone- or smart watch-based solution could provide accurate measures of compression depth and rate during simulated CPR. Fifty health care providers (58% intensive care unit nurses) performed simulated CPR on a calibrated training manikin (Resusci Anne, Laerdal) while wearing both devices. Subjects received real-time audiovisual feedback from each device sequentially. Primary outcome was accuracy of compression depth and rate compared with the calibrated training manikin. Secondary outcome was improvement in CPR quality as defined by meeting both guideline-recommend compression depth (5 to 6 cm) and rate (100 to 120/minute). Compared with the training manikin, typical error for compression depth was mobile device feedback (60% vs 50%; p = 0.3). Sessions that did not meet guideline recommendations failed primarily because of inadequate compression depth (46 ± 2 mm). In conclusion, a mobile device application-guided CPR can accurately track compression depth and rate during simulation in a practice environment in accordance with resuscitation guidelines. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. A Practical Hardware-Assisted Approach to Customize Trusted Boot for Mobile Devices

    DEFF Research Database (Denmark)

    Gonzalez, Javier; Hölzl, Michael; Riedl, Peter

    2014-01-01

    is maintained with the components that have been loaded in the boot process for later audit. The first approach is often criticized for locking down devices, thus reducing users’ freedom to choose software. The second lacks the mechanisms to enforce any form of run-time verification. In this paper, we present...

  2. Vapor cycle energy system for implantable circulatory assist devices. Annual progress report Jul 1974--Jun 1975

    International Nuclear Information System (INIS)

    Hagen, K.G.

    1975-06-01

    The report describes the development status of a heart assist system driven by a nuclear fueled, electronically controlled vapor cycle engine termed the tidal regenerator engine (TRE). The TRE pressurization (typically from 5-160 psia) is controlled by a torque motor coupled to a displacer. The electrical power for the sensor, electronic logic and actuator is provided by a thermoelectric module interposed between the engine superheater and boiler. The TRE is direct coupled to an assist blood pump which also acts as a blood-cooled heat exchanger, pressure-volume transformer and sensor for the electronic logic. Engine efficiencies in excess of 14% have been demonstrated. Efficiency values as high as 13% have been achieved to date

  3. Vapor cycle energy system for implantable circulatory assist devices. Final summary May--Oct 1976

    International Nuclear Information System (INIS)

    Watelet, R.P.; Ruggles, A.E.; Hagen, K.G.

    1977-03-01

    The report describes the development status of a heart assist system driven by a nuclear-fueled, electronically controlled vapor cycle engine termed the tidal regenerator engine (TRE). The TRE pressurization is controlled by a torque motor coupled to a displacer. The electrical power for the sensor, electronic logic and actuator is provided by thermoelectric modules interposed between the engine superheater and boiler. The TRE is direct-coupled to an assist blood pump which also acts as a blood-cooled heat exchanger, pressure-volume trasformer and sensor for the electronic logic. Engine cycle efficiency in excess of 14% has been demonstrated routinely. Overall system efficiency on 33 watts of over 9% has been demonstrated (implied 13% engine cycle efficiency). A binary version of this engine in the annular configuration is now being tested. The preliminary tests demonstrated 10% cycle efficiency on the first buildup which ran well and started easily

  4. Design and Implementation of NTU Wearable Exoskeleton as an Enhancement and Assistive Device

    OpenAIRE

    Low, K. H.; Liu, X.; Yu, H.

    2006-01-01

    This article presents a wearable lower extremity exoskeleton (LEE) developed to enhance the ability of a human’s walking while carrying heavy loads. The ultimate goal of the current research work is to design and control a power assist system that integrates a human’s intellect for feedback and sensory purposes. The exoskeleton system in this work consists of an inner exoskeleton and an outer exoskeleton. The inner exoskeleton measures the movements of the wearer and provides these measuremen...

  5. Comparison of devices used for stent-assisted coiling of intracranial aneurysms.

    Directory of Open Access Journals (Sweden)

    Benjamin Izar

    Full Text Available INTRODUCTION: Two self-expandable stents, the Neuroform and the Enterprise stent, are widely used for stent-assisted coiling (SAC of complex shaped intracranial aneurysms. However, comparative knowledge about technical feasibility, peri- and post-procedural morbidity and mortality, packing densities as well as follow-up data is limited. MATERIAL AND METHODS: We conducted a retrospective study to investigate differences in aneurysms stented with the Enterprise or Neuroform stents. Angiographic follow-up (mean 19.42 months was available in 72.6% (61/84 of aneurysms treated with stent-assisted coiling. We further sought to compare stent-assisted coiling to a matched patient population with aneurysms treated by conventional coil embolization. RESULTS: The stenting success rate of the Enterprise was higher compared to the Neuroform stent (46/48 and 42/51, respectively. In 5 of 9 cases in which the Neuroform stent was not navigable to the landing zone, we successfully deployed an Enterprise stent instead. Eventually, 42 aneurysms were coiled after stenting in each group. We observed no significant differences in peri-procedural complication rate, post-procedural hospital stay, packing density, recurrence rate or number of in-stent stenosis. Strikingly, 36.1% of followed aneurysms in the SAC group showed progressive occlusion on angiographic follow-up imaging. The packing density was significantly higher in aneurysms treated by SAC as compared to conventionally coiled aneurysms, while recanalization rate was significantly lower in the SAC group. CONCLUSION: The procedural success rate is higher using the Enterprise, but otherwise both stents exhibited similar characteristics. Lower recurrence frequency and complication rates comparable to conventional coil embolization emphasize the importance of stent-assisted coiling in the treatment of complex aneurysms. Progressive occlusion on angiographic follow-up was a distinct and frequent observation in the

  6. Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System.

    Science.gov (United States)

    Bozkurt, Selim; van de Vosse, Frans N; Rutten, Marcel C M

    Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.

  7. Biventricular MR volumetric analysis and MR flow quantification in the ascending aorta and pulmonary trunk for quantification of valvular regurgitation

    International Nuclear Information System (INIS)

    Rominger, M.B.

    2004-01-01

    Purpose: To test the value of biventricular volumetric analysis and the combination of biventricular volumetric analysis with flow quantification in the ascending aorta (Ao) and pulmonary trunk (Pu) for quantification of regurgitation volume and cardiac function in valvular regurgitation (VR) according to location and presence of single or multivalvular disease. Materials and Methods: In 106 patients, the stroke volumes were assessed by measuring the biventricular volumes and the forward-stroke volumes in the great and small circulation by measuring the flow in the Ao and Pu. Valve regurgitation volumes and quotients were calculated for single and multivalvular disease and correlated with semiquantitative 2D-echocardiography (grade I-IV). For the assessment of the cardiac function in VR, the volumetric parameters of ejection fraction and end-diastolic (EDV) and end-systolic (ESV) volumes were determined. Results: The detection rate was 49% for left ventricular (LV) VR and 42% for right ventricular (RV) VR. Low LV VR and RV VR usually could not be detected quantitatively, with the detection rate improving with echocardiographically higher insufficiency grades. Quantitative MRI could detect a higher grade solitary aortic valve insufficiency (≥2) in 11 of 12 patients and higher grade mitral valve insufficiency in 4 of 10 patients. A significant increase in RV and LV ventricular EDV and ESV was seen more often with increased MR regurgitation volumes. Aortic stenosis did not interfere with flow measurements in the Ao. Conclusions: Biventricular volumetry combined with flow measurements in Ao and Pu is a robust, applicable and simple method to assess higher grade regurgitation volumes and the cardiac function in single and multivalvular regurgitation at different locations. It is an important application for the diagnosis of VR by MRI [de

  8. Minimally Invasive Implantation of HeartWare Assist Device and Simultaneous Tricuspid Valve Reconstruction Through Partial Upper Sternotomy.

    Science.gov (United States)

    Hillebrand, Julia; Hoffmeier, Andreas; Djie Tiong Tjan, Tonny; Sindermann, Juergen R; Schmidt, Christoph; Martens, Sven; Scherer, Mirela

    2017-05-01

    Left ventricular assist device (LVAD) implantation is a well-established therapy to support patients with end-stage heart failure. However, the operative procedure is associated with severe trauma. Third generation LVADs like the HeartWare assist device (HeartWare, Inc., Framingham, MA, USA) are characterized by enhanced technology despite smaller size. These devices offer new minimally invasive surgical options. Tricuspid regurgitation requiring valve repair is frequent in patients with the need for mechanical circulatory support as it is strongly associated with ischemic and nonischemic cardiomyopathy. We report on HeartWare LVAD implantation and simultaneous tricuspid valve reconstruction through minimally invasive access by partial upper sternotomy to the fifth left intercostal space. Four male patients (mean age 51.72 ± 11.95 years) suffering from chronic heart failure due to dilative (three patients) and ischemic (one patient) cardiomyopathy and also exhibiting concomitant tricuspid valve insufficiency due to annular dilation underwent VAD implantation and tricuspid valve annuloplasty. Extracorporeal circulation was established via the ascending aorta, superior vena cava, and right atrium. In all four cases the LVAD implantation and tricuspid valve repair via partial median sternotomy was successful. During the operative procedure, no conversion to full sternotomy was necessary. One patient needed postoperative re-exploration because of pericardial effusion. No postoperative focal neurologic injury was observed. New generation VADs are advantageous because of the possibility of minimally invasive implantation procedure which can therefore minimize surgical trauma. Concomitant tricuspid valve reconstruction can also be performed simultaneously through partial upper sternotomy. Nevertheless, minimally invasive LVAD implantation is a challenging operative technique. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals

  9. Dispositivos de tecnología de asistencia para alimentación = Devices of assistive technology for feeding

    Directory of Open Access Journals (Sweden)

    Losada Gómez, A

    2007-02-01

    Full Text Available RESUMENEste artículo presenta los principales dispositivos de tecnología de asistencia que existen en Bogotá para facilitar el desempeño de la actividad de alimentación en personas que presentan algún tipo de discapacidad que limite esta ejecución, para ello, fue necesario realizar un estudio descriptivo donde se aplicó un instrumento tipo encuesta a personas que comercializan los mismos. Los principales resultados determinan que existen diferentes dispositivos para la función motora (mantener la postura sedente, facilitar agarres, facilitar patrón mano-boca y los patrones bucales (succión, deglución, masticación y digestión que se requieren en la alimentación. Como conclusión se determinó que actualmente en Colombia, los dispositivos de tecnología de asistencia para la alimentación son de baja tecnología y que existe fácil acceso a los mismos, pero se requiere realizar mayor difusión, también se encontró que no existen dispositivos que puedan facilitar esta actividad a personas que presenten parálisis en miembros superiores y que son mínimos los que presentan aplicación de tecnología de puntaABSTRACTThis article presents the principal devices of assistive technology that exist in Bogotá to facilitate the development of the activity of feeding in people that present some type of disability that limits this execution. Therefore, it was necessary to develop a descriptive study that included an instrument kind of inquiry to people that commercialize this devices. The principal results determine that there are different devices for the motor function (keep the sedentary posture, facilitate grips, facilitate hand-mouth patron and the buccal patrons (sucking, swallowing, chewing and digestion that are required in the feeding. As a conclusion it was determined that at present in Colombia, the devices of assistive technology for feeding have a low level of technology and there is an easy access to them, but is required to

  10. Trends in the Management of Patients With Left Ventricular Assist Devices Presenting for Noncardiac Surgery: A 10-Year Institutional Experience.

    Science.gov (United States)

    Stone, Marc; Hinchey, Joseph; Sattler, Christopher; Evans, Adam

    2016-09-01

    In our institution, the vast majority of patients presenting for noncardiac surgery (NCS) while supported by a left ventricular assist device (LVAD) are now cared for by noncardiac-trained anesthesiologists as the result of a decade of educational intervention to effect this transition. This represents a significant departure from the published experiences of other institutions. With institutional review board approval, we queried the database of our anesthesia record keeping system (CompuRecord) to determine various aspects of the perioperative management of these patients from July 1, 2003, through June 30, 2013, during which time 271 NCS procedures were performed on adult patients supported by LVADs. Over the entire study period (2003-2013), anesthetic care was provided by a cardiac anesthesiologist 47% of the time and by a noncardiac anesthesiologist 53% of the time. However, by the time period 2012-2013, 88% of the NCS procedures were staffed by a noncardiac anesthesiologist. Despite the prevalence of continuous flow devices in this series, the use of invasive blood pressure monitoring decreased dramatically by the later years of the study. Vasoactive and inotropic medications were rarely required intraoperatively. No intraoperative cardiac arrests, thromboembolic complications, or device malfunctions occurred. Our conclusion is that NCS procedures on LVAD-supported patients can be safely managed by educated noncardiac anesthesiologists. © The Author(s) 2015.

  11. New Innovations in Circulatory Support With Ventricular Assist Device and Extracorporeal Membrane Oxygenation Therapy.

    Science.gov (United States)

    Sladen, Robert N

    2017-04-01

    The past decade has seen an exponential increase in the application and development of durable long-term as well as nondurable short-term mechanical circulatory support for cardiogenic shock and acute or chronic heart failure. Support has evolved from bridge-to-transplant to destination therapy, bridge to rescue, bridge to decision making, and bridge to a bridge. Notable trends include device miniaturization, minimally invasive and/or percutaneous insertion, and efforts to superimpose pulsatility on continuous flow. We can certainly anticipate that innovation will accelerate in the months and years to come. However, despite-or perhaps because of-the enhanced equipment now available, mechanical circulatory support is an expensive, complex, resource-intensive modality. It requires considerable expertise that should preferably be centralized to highly specialized centers. Formidable challenges remain: systemic inflammatory response syndromes and vasoplegia after device insertion; postoperative sepsis; optimal anticoagulation regimens to prevent device-induced thrombosis and cerebral thromboembolism; wound site, intracranial, and gastrointestinal bleeding; multisystem injury and failure; patient dissatisfaction (even when providers consider the procedure a "success"); and ethical decision making in conditions of futility.

  12. Risk assessment and comparative effectiveness of left ventricular assist device and medical management in ambulatory heart failure patients: design and rationale of the ROADMAP clinical trial.

    Science.gov (United States)

    Rogers, Joseph G; Boyle, Andrew J; O'Connell, John B; Horstmanshof, Douglas A; Haas, Donald C; Slaughter, Mark S; Park, Soon J; Farrar, David J; Starling, Randall C

    2015-02-01

    Mechanical circulatory support is now a proven therapy for the treatment of patients with advanced heart failure and cardiogenic shock. The role for this therapy in patients with less severe heart failure is unknown. The objective of this study is to examine the impact of mechanically assisted circulation using the HeartMate II left ventricular assist device in patients who meet current US Food and Drug Administration-defined criteria for treatment but are not yet receiving intravenous inotropic therapy. This is a prospective, nonrandomized clinical trial of 200 patients treated with either optimal medical management or a mechanical circulatory support device. This trial will be the first prospective clinical evaluation comparing outcomes of patients with advanced ambulatory heart failure treated with either ongoing medical therapy or a left ventricular assist device. It is anticipated to provide novel insights regarding relative outcomes with each treatment and an understanding of patient and provider acceptance of the ventricular assist device therapy. This trial will also provide information regarding the risk of events in "stable" patients with advanced heart failure and guidance for the optimal timing of left ventricular assist device therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. The use of mobile devices as assistive technology in resource-limited environments: access for learners with visual impairments in Kenya.

    Science.gov (United States)

    Foley, Alan R; Masingila, Joanna O

    2015-07-01

    In this paper, the authors explore the use of mobile devices as assistive technology for students with visual impairments in resource-limited environments. This paper provides initial data and analysis from an ongoing project in Kenya using tablet devices to provide access to education and independence for university students with visual impairments in Kenya. The project is a design-based research project in which we have developed and are refining a theoretically grounded intervention--a model for developing communities of practice to support the use of mobile technology as an assistive technology. We are collecting data to assess the efficacy and improve the model as well as inform the literature that has guided the design of the intervention. In examining the impact of the use of mobile devices for the students with visual impairments, we found that the devices provide the students with (a) access to education, (b) the means to participate in everyday life and (c) the opportunity to create a community of practice. Findings from this project suggest that communities of practice are both a viable and a valuable approach for facilitating the diffusion and support of mobile devices as assistive technology for students with visual impairments in resource-limited environments. Implications for Rehabilitation The use of mobile devices as assistive technology in resource-limited environments provides students with visual impairments access to education and enhanced means to participate in everyday life. Communities of practice are both a viable and a valuable approach for facilitating the diffusion and support of mobile devices as assistive technology for students with visual impairments in resource-limited environments. Providing access to assistive technology early and consistently throughout students' schooling builds both their skill and confidence and also demonstrates the capabilities of people with visual impairments to the larger society.

  14. SdrF, a Staphylococcus epidermidis surface protein, contributes to the initiation of ventricular assist device driveline-related infections.

    Directory of Open Access Journals (Sweden)

    Carlos Arrecubieta

    2009-05-01

    Full Text Available Staphylococcus epidermidis remains the predominant pathogen in prosthetic-device infections. Ventricular assist devices, a recently developed form of therapy for end-stage congestive heart failure, have had considerable success. However, infections, most often caused by Staphylococcus epidermidis, have limited their long-term use. The transcutaneous driveline entry site acts as a potential portal of entry for bacteria, allowing development of either localized or systemic infections. A novel in vitro binding assay using explanted drivelines obtained from patients undergoing transplantation and a heterologous lactococcal system of surface protein expression were used to identify S. epidermidis surface components involved in the pathogenesis of driveline infections. Of the four components tested, SdrF, SdrG, PIA, and GehD, SdrF was identified as the primary ligand. SdrF adherence was mediated via its B domain attaching to host collagen deposited on the surface of the driveline. Antibodies directed against SdrF reduced adherence of S. epidermidis to the drivelines. SdrF was also found to adhere with high affinity to Dacron, the hydrophobic polymeric outer surface of drivelines. Solid phase binding assays showed that SdrF was also able to adhere to other hydrophobic artificial materials such as polystyrene. A murine model of infection was developed and used to test the role of SdrF during in vivo driveline infection. SdrF alone was able to mediate bacterial adherence to implanted drivelines. Anti-SdrF antibodies reduced S. epidermidis colonization of implanted drivelines. SdrF appears to play a key role in the initiation of ventricular assist device driveline infections caused by S. epidermidis. This pluripotential adherence capacity provides a potential pathway to infection with SdrF-positive commensal staphylococci first adhering to the external Dacron-coated driveline at the transcutaneous entry site, then spreading along the collagen

  15. EMPLOYMENT OF ATMS TRAFFIC CONTROL DEVICE DATA TO ASSIST IN IDENTIFICATION OF CRASH-PRONE INTERSECTIONS

    Directory of Open Access Journals (Sweden)

    Kevin P. HWANG

    2008-01-01

    Full Text Available This paper employs information from the advanced traffic management system (ATMS of Kaohsiung, Taiwan to help differentiate those crash-prone intersections by discriminant analysis. From the 25,604 records of 2005, 1977 crashes that occurred at 119 intersections with traffic exposure data were compiled to calibrate and validate the model. The road attributes of crash records, traffic control devices and movement exposure are the three types of data used as predicting variables. The correct ratios for model calibration and validation range from 78.33% to 67.80%. if traffic movements are removed, the correct ratios become slightly lowered to 76.67% to 66.10%. Research findings reveal that with or without inclusion of exposure data in identifying high crash-prone intersections for an urban environment does not make a significant difference. in addition, layout and traffic control devices could possibly explain about 66.10 ∼ 78.33% of the possibility that an intersection will become a high crash intersection. it suggests that the developed approach could be a countermeasure for budget constraints and difficulties in continuation of exposure data collection, and the information of ATMS could help identify crash-prone urban intersections.

  16. Two dimensional PMMA nanofluidic device fabricated by hot embossing and oxygen plasma assisted thermal bonding methods

    Science.gov (United States)

    Yin, Zhifu; Sun, Lei; Zou, Helin; Cheng, E.

    2015-05-01

    A method for obtaining a low-cost and high-replication precision two-dimensional (2D) nanofluidic device with a polymethyl methacrylate (PMMA) sheet is proposed. To improve the replication precision of the 2D PMMA nanochannels during the hot embossing process, the deformation of the PMMA sheet was analyzed by a numerical simulation method. The constants of the generalized Maxwell model used in the numerical simulation were calculated by experimental compressive creep curves based on previously established fitting formula. With optimized process parameters, 176 nm-wide and 180 nm-deep nanochannels were successfully replicated into the PMMA sheet with a replication precision of 98.2%. To thermal bond the 2D PMMA nanochannels with high bonding strength and low dimensional loss, the parameters of the oxygen plasma treatment and thermal bonding process were optimized. In order to measure the dimensional loss of 2D nanochannels after thermal bonding, a dimension loss evaluating method based on the nanoindentation experiments was proposed. According to the dimension loss evaluating method, the total dimensional loss of 2D nanochannels was 6 nm and 21 nm in width and depth, respectively. The tensile bonding strength of the 2D PMMA nanofluidic device was 0.57 MPa. The fluorescence images demonstrate that there was no blocking or leakage over the entire microchannels and nanochannels.

  17. Universal algorithm for diagnosis of biventricular capture in patients with cardiac resynchronization therapy.

    Science.gov (United States)

    Jastrzebski, Marek; Kukla, Piotr; Fijorek, Kamil; Czarnecka, Danuta

    2014-08-01

    An accurate and universal method for diagnosis of biventricular (BiV) capture using a standard 12-lead electrocardiogram (ECG) would be useful for assessment of cardiac resynchronization therapy (CRT) patients. Our objective was to develop and validate such an ECG method for BiV capture diagnosis that would be independent of pacing lead positions-a major confounder that significantly influences the morphologies of paced QRS complexes. On the basis of an evaluation of 789 ECGs of 443 patients with heart failure and various right ventricular (RV) and left ventricular (LV) lead positions, the following algorithm was constructed and validated. BiV capture was diagnosed if the QRS in lead I was predominantly negative and either V1 QRS was predominantly positive or V6 QRS was of negative onset and predominantly negative (step 1), or if QRS complex duration was capture. The algorithm showed good accuracy (93%), sensitivity (97%), and specificity (90%) for detection of loss of LV capture. The performance of the algorithm did not differ among apical, midseptal, and outflow tract RV lead positions and various LV lead positions. LV capture leaves diagnostic hallmarks in the fused BiV QRS related to different vectors of depolarization and more rapid depolarization of the ventricles. An accurate two-step ECG algorithm for BiV capture diagnosis was developed and validated. This algorithm is universally applicable to all CRT patients, regardless of the positions of the pacing leads. ©2014 Wiley Periodicals, Inc.

  18. Efficiency of timing delays and electrode positions in optimization of biventricular pacing: a simulation study.

    Science.gov (United States)

    Miri, Raz; Graf, Iulia M; Dössel, Olaf

    2009-11-01

    Electrode positions and timing delays influence the efficacy of biventricular pacing (BVP). Accordingly, this study focuses on BVP optimization, using a detailed 3-D electrophysiological model of the human heart, which is adapted to patient-specific anatomy and pathophysiology. The research is effectuated on ten heart models with left bundle branch block and myocardial infarction derived from magnetic resonance and computed tomography data. Cardiac electrical activity is simulated with the ten Tusscher cell model and adaptive cellular automaton at physiological and pathological conduction levels. The optimization methods are based on a comparison between the electrical response of the healthy and diseased heart models, measured in terms of root mean square error (E(RMS)) of the excitation front and the QRS duration error (E(QRS)). Intra- and intermethod associations of the pacing electrodes and timing delays variables were analyzed with statistical methods, i.e., t -test for dependent data, one-way analysis of variance for electrode pairs, and Pearson model for equivalent parameters from the two optimization methods. The results indicate that lateral the left ventricle and the upper or middle septal area are frequently (60% of cases) the optimal positions of the left and right electrodes, respectively. Statistical analysis proves that the two optimization methods are in good agreement. In conclusion, a noninvasive preoperative BVP optimization strategy based on computer simulations can be used to identify the most beneficial patient-specific electrode configuration and timing delays.

  19. Vacuum-assisted closure device: a useful tool in the management of severe intrathoracic infections.

    Science.gov (United States)

    Saadi, Alend; Perentes, Jean Yannis; Gonzalez, Michel; Tempia, Adrien Caliera; Wang, Yabo; Demartines, Nicolas; Ris, Hans-Beat; Krueger, Thorsten

    2011-05-01

    This study is an evaluation of the vacuum-assisted closure (VAC) therapy for the treatment of severe intrathoracic infections complicating lung resection, esophageal surgery, viscera perforation, or necrotizing pleuropulmonary infections. We reviewed the medical records of all patients treated by intrathoracic VAC therapy between January 2005 and December 2008. All patients underwent surgical debridement-decortication and control of the underlying cause of infection such as treatment of bronchus stump insufficiency, resection of necrotic lung, or closure of esophageal or intestinal leaks. Surgery was followed by intrathoracic VAC therapy until the infection was controlled. The VAC dressings were changed under general anesthesia and the chest wall was temporarily closed after each dressing change. All patients received systemic antibiotic therapy. Twenty-seven patients (15 male, median age 64 years) underwent intrathoracic VAC dressings for the management of postresectional empyema (n=8) with and without bronchopleural fistula, necrotizing infections (n=7), and intrathoracic gastrointestinal leaks (n=12). The median length of VAC therapy was 22 days (range 5 to 66) and the median number of VAC changes per patient was 6 (range 2 to 16). In-hospital mortality was 19% (n=5) and was not related to VAC therapy or intrathoracic infection. Control of intrathoracic infection and closure of the chest cavity was achieved in all surviving patients. Vacuum-assisted closure therapy is an efficient and safe adjunct to treat severe intrathoracic infections and may be a good alternative to the open window thoracostomy in selected patients. Long time intervals in between VAC changes and short course of therapy result in good patient acceptance. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  20. Comparison between biventricular cine MRI and MR flow quantification in ascending aorta and pulmonary outflow tract for the assessment of intracardial shunt volumes

    International Nuclear Information System (INIS)

    Rominger, M.B.; Kluge, A.; Bachmann, G.F.; Dinkel, H.P.

    2002-01-01

    Purpose: Comparison between biventricular volumetric measurements and flow measurements in ascending aorta (Ao) and pulmonary outflow tract (Pu) for quantification of intracardial shunts, and evaluation of the combination of biventricular cine MRI with flow measurements for the assessment of RV and LV heart failure and valvular regurgitation (VR). Material and Methods: In 24 patients, right (RV) and left (LV) ventricular volumetric and flow measurements were performed in the Ao and Pu to assess the ratio of RV stroke volume (SV) or, respectively, pulmonary SV to LV SV or, respectively, systemic aortic SV (Qp/Qs). 34 patients without echocardiographically proven shunt or VR served as control group for measurement accuracy. Left-to-right shunt ratios were calculated from RV and LV SV, Pu and Ao SV, Pu and LV SV, and RV and Ao SV. Left ventricular VR was calculated by the difference of LV SV and Ao SV, and right ventricular VR by the difference of RV SV and Pu SV. Global systolic function was evaluated by biventricular cine MRI. Results: Intracardial shunts with Qp/Qs>1,16 can be quantified by flow measurements in Ao and Pu. Using biventricular volumetric measurements in cases without VR, requires a Qp/Qs>1.21. 17 of 18 intracardiac shunts were identified on MRI, and all 8 hemodynamically significant shunts were quantitatively confirmed. The diagnosis of complete shunt closure or absent shunt was correctly made in all 6 cases RV EF reduction was found in 6 of 24 patients. LV EF reduction was also found in 6 of 24 patients. Conclusion: Flow measurements in Ao and Pu are more accurate than biventricular cine MRI for the assessment of Qp/Qs ratios. Flow measurements in Ao and Pu combined with biventricular cine MRI enables the quantification of hemodynamic significant shunts, higher grade VR and biventricular global systolic function with a single examination. (orig.) [de

  1. Predictors of changes in health status between and within patients 12 months post left ventricular assist device implantation

    DEFF Research Database (Denmark)

    Brouwers, Corline; de Jonge, Nicolaas; Caliskan, Kadir

    2014-01-01

    improvements in health status between baseline and 3 months follow-up as assessed by the KCCQ (clinical summary score: F = 33.49, P physical component score: F = 31.59, P ... 3 months and 12 months follow-up (P > 0.05 for all). Higher scores on anxiety and depression over time, older age, lower ejection fraction, and more co-morbidity were associated with poorer health status scores on one or both of the KCCQ and SF-12 subscales. The majority of the between......BACKGROUND: Improving patient-reported outcomes (e.g. health status) has become an important goal in left ventricular assist device (LVAD) therapy, in addition to reducing mortality and morbidity. We examined predictors of changes in health status scores between and within patients 12 months post...

  2. Discontinuation of antithrombotic therapy for a year or more in patients with continuous-flow left ventricular assist devices.

    Science.gov (United States)

    Pereira, Naveen L; Chen, Dong; Kushwaha, Sudhir S; Park, Soon J

    2010-10-01

    The recommended anticoagulation regimen during continuous-flow axial left ventricular assist device (LVAD) support is aspirin and warfarin with a targeted international normalized ratio of 2.0-3.0. We report two patients in whom recurrent gastrointestinal bleeding during LVAD support necessitated discontinuation of this anti-thrombotic regimen for a year or more. Despite this, neither patients developed thrombotic complications during 29 patient-months of follow-up. An acquired von Willebrand factor (VWF) abnormality reflected by the absence or decreased abundance of the highest molecular weight multimers was demonstrated in both patients. The gold standard test for platelet function, light transmission platelet aggregometry was measured in one patient and was normal, indicative that the predominant abnormality in the coagulation profile of these patients is an acquired VWF syndrome. Clinical trials are required to address the question whether it is safe to discontinue anticoagulation in LVAD patients with acquired VWF abnormalities.

  3. Ventricular fibrillation in an ambulatory patient supported by a left ventricular assist device: highlighting the ICD controversy.

    Science.gov (United States)

    Boilson, Barry A; Durham, Lucian A; Park, Soon J

    2012-01-01

    Left ventricular assist devices (LVADs) provide an effective means of managing advanced pump failure as a means of bridging to cardiac transplantation or as permanent therapy. Although ventricular arrhythmias remain common post-LVAD implantation, such therapy may allow malignant arrhythmias to be tolerated hemodynamically. This report describes the clinical findings in a patient who had likely been in a ventricular tachyarrhythmia for several days and presented in ventricular fibrillation, ambulatory, and mentating normally. This report, with previous similar reports, is additive to the body of evidence that LVADs alter the physiologic impact of ventricular arrhythmias in advanced heart failure and highlights the need for thoughtful programming of implantable cardioverter defibrillator therapies in these patients.

  4. Neurohormonal activation and exercise tolerance in patients supported with a continuous-flow left ventricular assist device

    DEFF Research Database (Denmark)

    Jung, Mette Holme; Goetze, Jens Peter; Boesgaard, Soeren

    2016-01-01

    BACKGROUND: Neurohormones play a key role in regulating hemodynamics in heart failure (HF) both at rest and during exercise. In contrast, little is known about the importance of neurohormonal regulation for exercise capacity in continuous-flow left ventricular assist device (CF-LVAD) patients....... The aim of this study was to assess the relation between neurohormonal activation patterns in CF-LVAD patients and exercise capacity. METHODS: Plasma concentrations of the C-terminal portion of pro-arginine vasopressin precursor (copeptin), pro-adrenomedullin (proADM), pro-B-type (proBNP) and pro......-atrial (proANP) natriuretic peptides were measured in 25 CF-LVAD patients (HeartMate II) in the morning prior to maximal cardiopulmonary exercise testing determining peak oxygen uptake (peak VO2). Quality of life (QOL) was determined by questionnaires. RESULTS: Peak VO2 was severely reduced averaging 13...

  5. Successful Implantation of a Left Ventricular Assist Device in a Patient with Heparin-Induced Thrombocytopenia and Thrombosis

    Science.gov (United States)

    Garland, Cassandra; Somogyi, David

    2014-01-01

    Abstract: We report the case of a 27-year-old woman with signs of heparin-induced thrombocytopenia and thrombosis (HITT) and left heart failure presenting for urgent implantation of a left ventricular assist device (LVAD). HITT can occur in 4.2–6.1% of patients with LVADs. If the patient remains hemodynamically stable, implantation can be delayed for several months until the heparin/PF-4 antibodies decline allowing the use of heparin on cardiopulmonary bypass, However, in most cases related to cardiogenic shock, surgery cannot be delayed. We present the case of a patient who underwent implantation of a HeartMate II LVAD and discuss management strategy using bivalirudin during cardiopulmonary bypass. PMID:25208434

  6. Laser-assisted ultrathin bare die packaging: a route to a new class of microelectronic devices

    Science.gov (United States)

    Marinov, Val R.; Swenson, Orven; Atanasov, Yuriy; Schneck, Nathan

    2013-03-01

    Ultrathin flip-chip semiconductor die packaging on paper substrates is an enabling technology for a variety of extremely low-cost electronic devices with huge market potential such as RFID smart forms, smart labels, smart tickets, banknotes, security documents, etc. Highly flexible and imperceptible dice are possible only at a thickness of less than 50 μm, preferably down to 10-20 μm or less. Several cents per die cost is achievable only if the die size is size and thickness. LEAP-packaged RFID-enabled paper for financial and security applications is also demonstrated. The cost of packaging using LEAP is lower compared to the conventional pick-and-place methods while the rate of packaging is much higher and independent of the die size.

  7. [Orthoses and assistive devices in rheumatology : Prevention of disability, support of residual function].

    Science.gov (United States)

    Fikentscher, T; Springorum, H R; Grifka, J; Götz, J

    2017-04-01

    Due to the frequent presence of comorbidities in patients suffering from rheumatism with increased perioperative risk factors, conservative treatment is often needed. Besides pharmacological treatment, physiotherapy and occupational therapy, a variety of orthoses are available depending on the individual indications. They can be used to stabilize or support joints, limit the range of motion, prevent unphysiological movements or provide relief for affected limbs. In order to choose the right kind of orthosis, the physician should know the underlying cause of disease. Furthermore, for patients with rheumatism many devices are available for daily living that use ergonomic handles or improved leverage effects to compensate for the often severe limitations and to improve the quality of life.

  8. Assistive devices for balance and mobility: benefits, demands, and adverse consequences.

    Science.gov (United States)

    Bateni, Hamid; Maki, Brian E

    2005-01-01

    To provide information on the advantages and possible disadvantages of using canes and walkers. English-language articles were identified by searching MEDLINE and PubMed (1966-May 2003) for key words cane or walker , excluding articles unrelated to mobility aids. Bibliographies were reviewed and ISI Web of Science citation searches were run to identify additional references. Over 1000 articles were selected for further evaluation. We extracted all studies of single-tip canes or pickup walkers addressing: (1) functional, biomechanic, or neuromotor benefits; (2) biomechanic, attentional, neuromotor, metabolic, or physiologic demands; and (3) falls, injuries, or other problems. We included approximately 10% of the articles originally identified. The methodology of each selected article, and findings relevant to the benefits, demands, or adverse effects of cane or walker use were summarized. Findings were synthesized by considering their relation to basic biomechanic principles. Some biomechanic findings appear to support the clinical view that canes and walkers can improve balance and mobility for older adults and people with other clinical conditions. However, a large proportion of users experience difficulties, and the use of such devices is associated with increased risk of falling. A small number of studies have characterized some of the specific demands and problems associated with using mobility aids. Clinical and biomechanic evaluations of canes and walkers confirm that these devices can improve balance and mobility. However, they can also interfere with ones ability to maintain balance in certain situations, and the strength and metabolic demands can be excessive. More research is needed to identify and solve specific problems. Such research may lead to improved designs and guidelines for safer use of canes and walkers.

  9. Model-assisted template extraction SRAF application to contact holes patterns in high-end flash memory device fabrication

    Science.gov (United States)

    Seoud, Ahmed; Kim, Juhwan; Ma, Yuansheng; Jayaram, Srividya; Hong, Le; Chae, Gyu-Yeol; Lee, Jeong-Woo; Park, Dae-Jin; Yune, Hyoung-Soon; Oh, Se-Young; Park, Chan-Ha

    2018-03-01

    Sub-resolution assist feature (SRAF) insertion techniques have been effectively used for a long time now to increase process latitude in the lithography patterning process. Rule-based SRAF and model-based SRAF are complementary solutions, and each has its own benefits, depending on the objectives of applications and the criticality of the impact on manufacturing yield, efficiency, and productivity. Rule-based SRAF provides superior geometric output consistency and faster runtime performance, but the associated recipe development time can be of concern. Model-based SRAF provides better coverage for more complicated pattern structures in terms of shapes and sizes, with considerably less time required for recipe development, although consistency and performance may be impacted. In this paper, we introduce a new model-assisted template extraction (MATE) SRAF solution, which employs decision tree learning in a model-based solution to provide the benefits of both rule-based and model-based SRAF insertion approaches. The MATE solution is designed to automate the creation of rules/templates for SRAF insertion, and is based on the SRAF placement predicted by model-based solutions. The MATE SRAF recipe provides optimum lithographic quality in relation to various manufacturing aspects in a very short time, compared to traditional methods of rule optimization. Experiments were done using memory device pattern layouts to compare the MATE solution to existing model-based SRAF and pixelated SRAF approaches, based on lithographic process window quality, runtime performance, and geometric output consistency.

  10. A numerical method to enhance the performance of a cam-type electric motor-driven left ventricular assist device.

    Science.gov (United States)

    Huang, Huan; Yang, Ming; Lu, Cunyue; Xu, Liang; Zhuang, Xiaoqi; Meng, Fan

    2013-10-01

    Pulsatile left ventricular assist devices (LVADs) driven by electric motors have been widely accepted as a treatment of heart failure. Performance enhancement with computer assistance for this kind of LVAD has seldom been reported. In this article, a numerical method is proposed to assist the design of a cam-type pump. The method requires an integrated model of an LVAD system, consisting of a motor, a transmission mechanism, and a cardiovascular circulation. Performance indices, that is, outlet pressure, outlet flow, and pump efficiency, were used to select the best cam profile from six candidates. A prototype pump connected to a mock circulatory loop (MCL) was used to calibrate the friction coefficient of the cam groove and preliminarily evaluate modeling accuracy. In vitro experiments show that the mean outlet pressure and flow can be predicted with high accuracy by the model, and gross geometries of the measurements can also be reproduced. Simulation results demonstrate that as the total peripheral resistance (TPR) is fixed at 1.1 mm Hg.s/mL, the two-cycle 2/3-rise profile is the best. Compared with other profiles, the maximum increases of pressure and flow indices are 75 and 76%, respectively, and the maximum efficiency increase is over 51%. For different TPRs (0.5∼1.5 mm Hg.s/mL) and operation intervals (0.1∼0.4 s) in counterpulsation, the conclusion is also acceptable. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

  11. Design and Implementation of NTU Wearable Exoskeleton as an Enhancement and Assistive Device

    Directory of Open Access Journals (Sweden)

    K. H. Low

    2006-01-01

    Full Text Available This article presents a wearable lower extremity exoskeleton (LEE developed to enhance the ability of a human’s walking while carrying heavy loads. The ultimate goal of the current research work is to design and control a power assist system that integrates a human’s intellect for feedback and sensory purposes. The exoskeleton system in this work consists of an inner exoskeleton and an outer exoskeleton. The inner exoskeleton measures the movements of the wearer and provides these measurements to the outer exoskeleton, which supports the whole exoskeleton system to walk following the wearer. A special footpad, which is designed and attached to the outer exoskeleton, can measure the zero moment point (ZMP of the human as well as that of the exoskeleton in time. Using the measured human ZMP as the reference, the exoskeleton’s ZMP is controlled by trunk compensation so that the exoskeleton can walk stably. A simulation platform has first been developed to examine the gait coordination through inner and outer exoskeletons. A commercially available software, xPC Target, together with other toolboxes from MATLAB, has then been used to provide a real-time operating system for controlling the exoskeleton. Real-time locomotion control of the exoskeleton is implemented in the developed environment. Finally, some experiments on different objects showed that the stable walking can be achieved in the real environment.

  12. Peripheral Artery Disease and Continuous Flow Left Ventricle Assist Device: An Engaging Complement Analysis May Help to Guide Treatment.

    Science.gov (United States)

    Falletta, Calogero; Pasta, Salvatore; Raffa, Giuseppe Maria; Crinò, Francesca; Sciacca, Sergio; Clemenza, Francesco

    2018-02-13

    Use of continuous flow left ventricle assist device (CF-LVAD) in advanced heart failure (HF) patients results in clinically relevant improvements in survival, functional capacity, and quality of life. Peripheral artery disease (PAD) can occur in patients with CF-LVAD due to the high rate of concomitance between risk factors for atherosclerosis and HF. Diagnosis of PAD can be difficult in the specific setting of a patient supported by this kind of device because of the marked alteration in waveform morphology and velocity created by the artificial physiology of an LVAD. We report the case of a 53-year-old man with HF secondary to ischemic cardiomyopathy supported by the HeartWare HVAD as bridge to transplant, who after the implant developed symptoms suggestive of PAD. We describe additional computational flow analysis for the study of PAD-related hemodynamic disturbances induced by a CF-LVAD. Flow simulations enhance the information of clinical image data, and may have an application in clinical investigations of the risk of hemodynamic disturbances induced by LVAD implantation. © 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  13. In vivo evaluation of zirconia ceramic in the DexAide right ventricular assist device journal bearing.

    Science.gov (United States)

    Saeed, Diyar; Shalli, Shanaz; Fumoto, Hideyuki; Ootaki, Yoshio; Horai, Tetsuya; Anzai, Tomohiro; Zahr, Roula; Horvath, David J; Massiello, Alex L; Chen, Ji-Feng; Dessoffy, Raymond; Catanese, Jacquelyn; Benefit, Stephen; Golding, Leonard A R; Fukamachi, Kiyotaka

    2010-06-01

    Zirconia is a ceramic with material properties ideal for journal bearing applications. The purpose of this study was to evaluate the use of zirconium oxide (zirconia) as a blood journal bearing material in the DexAide right ventricular assist device. Zirconia ceramic was used instead of titanium to manufacture the DexAide stator housing without changing the stator geometry or the remaining pump hardware components. Pump hydraulic performance, journal bearing reliability, biocompatibility, and motor efficiency data of the zirconia stator were evaluated in six chronic bovine experiments for 14-91 days and compared with data from chronic experiments using the titanium stator. Pump performance data including average in vivo pump flows and speeds using a zirconia stator showed no statistically significant difference to the average values for 16 prior titanium stator in vivo studies, with the exception of a 19% reduction in power consumption. Indices of hemolysis were comparable for both stator types. Results of coagulation assays and platelet aggregation tests for the zirconia stator implants showed no device-induced increase in platelet activation. Postexplant evaluation of the zirconia journal bearing surfaces showed no biologic deposition in any of the implants. In conclusion, zirconia ceramic can be used as a hemocompatible material to improve motor efficiency while maintaining hydraulic performance in a blood journal bearing application.

  14. Vacuum-assisted closure device as a split-thickness skin graft bolster in the burn population.

    Science.gov (United States)

    Waltzman, Joshua T; Bell, Derek E

    2014-01-01

    The vacuum-assisted closure device (VAC) is associated with improved wound healing outcomes. Its use as a bolster device to secure a split-thickness skin graft has been previously demonstrated; however, there is little published evidence demonstrating its benefits specifically in the burn population. With use of the VAC becoming more commonplace, its effect on skin graft take and overall time to healing in burn patients deserves further investigation. Retrospective review of burn registry database at a high-volume level I trauma center and regional burn center during a 16-month period was performed. Patients who had a third-degree burn injury requiring a split-thickness skin graft and who received a VAC bolster were included. Data points included age, sex, burn mechanism, burn location, grafted area in square centimeters, need for repeat grafting, percent graft take, and time to complete reepithelialization. Sixty-seven patients were included in the study with a total of 88 skin graft sites secured with a VAC. Age ranged from skin graft in the burn population. The observed rate of zero returns to the operating room for repeat grafting was especially encouraging. Its ability to conform to contours of the body and cover large surface areas makes it especially useful in securing a graft. This method of bolstering results in decreased repeat grafting and minimal graft loss, thus decreasing morbidity compared with conventional bolster dressings.

  15. Flow visualization of three-dimensionality inside the 12 cc Penn State pulsatile pediatric ventricular assist device.

    Science.gov (United States)

    Roszelle, Breigh N; Deutsch, Steven; Manning, Keefe B

    2010-02-01

    In order to aid the ongoing concern of limited organ availability for pediatric heart transplants, Penn State has continued development of a pulsatile Pediatric Ventricular Assist Device (PVAD). Initial studies of the PVAD observed an increase in thrombus formation due to differences in flow field physics when compared to adult sized devices, which included a higher degree of three-dimensionality. This unique flow field brings into question the use of 2D planar particle image velocimetry (PIV) as a flow visualization technique, however the small size and high curvature of the PVAD make other tools such as stereoscopic PIV impractical. In order to test the reliability of the 2D results, we perform a pseudo-3D PIV study using planes both parallel and normal to the diaphragm employing a mock circulatory loop containing a viscoelastic fluid that mimics 40% hematocrit blood. We find that while the third component of velocity is extremely helpful to a physical understanding of the flow, particularly of the diastolic jet and the development of a desired rotational pattern, the flow data taken parallel to the diaphragm is sufficient to describe the wall shear rates, a critical aspect to the study of thrombosis and design of such pumps.

  16. Central-Approach Surgical Repair of Coarctation of the Aorta with a Back-up Left Ventricular Assist Device for an Infant Presenting with Severe Left Ventricular Dysfunction

    Directory of Open Access Journals (Sweden)

    Tae Hoon Kim

    2015-12-01

    Full Text Available A two-month-old infant presented with coarctation of the aorta, severe left ventricular dysfunction, and moderate to severe mitral regurgitation. Through median sternotomy, the aortic arch was repaired under cardiopulmonary bypass and regional cerebral perfusion. The patient was postoperatively supported with a left ventricular assist device for five days. Left ventricular function gradually improved, eventually recovering with the concomitant regression of mitral regurgitation. Prompt surgical repair of coarctation of the aorta is indicated for patients with severe left ventricular dysfunction. A central approach for surgical repair with a back-up left ventricular assist device is a safe and effective treatment strategy for these patients.

  17. Central-Approach Surgical Repair of Coarctation of the Aorta with a Back-up Left Ventricular Assist Device for an Infant Presenting with Severe Left Ventricular Dysfunction.

    Science.gov (United States)

    Kim, Tae Hoon; Shin, Yu Rim; Kim, Young Sam; Kim, Do Jung; Kim, Hyohyun; Shin, Hong Ju; Htut, Aung Thein; Park, Han Ki

    2015-12-01

    A two-month-old infant presented with coarctation of the aorta, severe left ventricular dysfunction, and moderate to severe mitral regurgitation. Through median sternotomy, the aortic arch was repaired under cardiopulmonary bypass and regional cerebral perfusion. The patient was postoperatively supported with a left ventricular assist device for five days. Left ventricular function gradually improved, eventually recovering with the concomitant regression of mitral regurgitation. Prompt surgical repair of coarctation of the aorta is indicated for patients with severe left ventricular dysfunction. A central approach for surgical repair with a back-up left ventricular assist device is a safe and effective treatment strategy for these patients.

  18. Verification of a computational cardiovascular system model comparing the hemodynamics of a continuous flow to a synchronous valveless pulsatile flow left ventricular assist device.

    Science.gov (United States)

    Gohean, Jeffrey R; George, Mitchell J; Pate, Thomas D; Kurusz, Mark; Longoria, Raul G; Smalling, Richard W

    2013-01-01

    The purpose of this investigation is to use a computational model to compare a synchronized valveless pulsatile left ventricular assist device with continuous flow left ventricular assist devices at the same level of device flow, and to verify the model with in vivo porcine data. A dynamic system model of the human cardiovascular system was developed to simulate the support of a healthy or failing native heart from a continuous flow left ventricular assist device or a synchronous pulsatile valveless dual-piston positive displacement pump. These results were compared with measurements made during in vivo porcine experiments. Results from the simulation model and from the in vivo counterpart show that the pulsatile pump provides higher cardiac output, left ventricular unloading, cardiac pulsatility, and aortic valve flow as compared with the continuous flow model at the same level of support. The dynamic system model developed for this investigation can effectively simulate human cardiovascular support by a synchronous pulsatile or continuous flow ventricular assist device.

  19. Applying a soft-robotic glove as assistive device and training tool with games to support hand function after stroke: Preliminary results on feasibility and potential clinical impact.

    Science.gov (United States)

    Prange-Lasonder, Gerdienke B; Radder, Bob; Kottink, Anke I R; Melendez-Calderon, Alejandro; Buurke, Jaap H; Rietman, Johan S

    2017-07-01

    Recent technological developments regarding wearable soft-robotic devices extend beyond the current application of rehabilitation robotics and enable unobtrusive support of the arms and hands during daily activities. In this light, the HandinMind (HiM) system was developed, comprising a soft-robotic, grip supporting glove with an added computer gaming environment. The present study aims to gain first insight into the feasibility of clinical application of the HiM system and its potential impact. In order to do so, both the direct influence of the HiM system on hand function as assistive device and its therapeutic potential, of either assistive or therapeutic use, were explored. A pilot randomized clinical trial was combined with a cross-sectional measurement (comparing performance with and without glove) at baseline in 5 chronic stroke patients, to investigate both the direct assistive and potential therapeutic effects of the HiM system. Extended use of the soft-robotic glove as assistive device at home or with dedicated gaming exercises in a clinical setting was applicable and feasible. A positive assistive effect of the soft-robotic glove was proposed for pinch strength and functional task performance 'lifting full cans' in most of the five participants. A potential therapeutic impact was suggested with predominantly improved hand strength in both participants with assistive use, and faster functional task performance in both participants with therapeutic application.

  20. Hepatic and renal function with successful long-term support on a continuous flow left ventricular assist device.

    Science.gov (United States)

    Deo, Salil V; Sharma, Vikas; Altarabsheh, Salah E; Hasin, Tal; Dillon, John; Shah, Ishan K; Durham, Lucian A; Stulak, John M; Daly, Richard C; Joyce, Lyle D; Park, Soon J

    2014-03-01

    Data regarding the long-term clinical effects of a continuous flow left ventricular assist device (CF-LVAD) on hepato-renal function is limited. Hence our aim was to assess changes in hepato-renal function over a one-year period in patients supported on a CF-LVAD. During the study period 126 patients underwent CF-LVAD implant. Changes in hepato-renal laboratory parameters were studied in 61/126 patients successfully supported on a CF-LVAD for period of one year. A separate cohort of a high-risk group (HCrB) of patients (56/126) with a serum creat>1.9 mg/dL (168 μmol/L) (75th percentile) or a serum bil>1.5 mg/dL (25.65 μmol/L) (75th percentile) was created. Changes in serum creatinine and bilirubin were analysed at regular intervals for this group along with the need for renal replacement therapy. Baseline creatinine and blood urea nitrogen (BUN) for the entire cohort was 1.4[1.2,1.9 mg/dL] [123.7(106,168) μmol/L) and 27[20,39.5 mg/dL] [9.6(7.1,14.1) mmol/L] respectively. After an initial reduction at the end of one month [1(0.8,1.2) mg/dL; 88(70,105) μmol/L] (passist device support for one year. High-risk patients demonstrate a higher 30-day mortality and temporary need for renal replacement therapy. Yet even in this cohort, improvement is present over a period of one year on the device, with a minimal need for permanent haemodialysis. Copyright © 2013 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  1. A difficult decision: what should we do when malignant tumours are diagnosed in patients supported by left ventricular assist devices?

    Science.gov (United States)

    Smail, Hassiba; Pfister, Christian; Baste, Jean-Marc; Nafeh-Bizet, Catherine; Gay, Arnaud; Barbay, Virginie; Bessou, Jean-Paul; Peillon, Christophe; Litzler, Pierre-Yves

    2015-09-01

    Left ventricular assist devices (LVADs) are used as a bridge to heart transplantation. During the preimplantation or pretransplantation screening, malignant tumours can be discovered. Owing to the lack of guidelines, the management is difficult. We describe our perioperative approach and the patients' outcomes. Between 2006 and 2014, 55 patients underwent implantation of HeartMate II LVAD. Five were diagnosed with malignant tumours: 2 renal, 2 lung and 1 breast tumours. The renal tumours were diagnosed during the preimplantation screening. An LVAD was implanted in both followed by partial nephrectomies 8 and 9 months later. The lung cancers were diagnosed after device implantation, a left pulmonary segmentectomy and a right upper sleeve lobectomy were performed. The breast cancer was diagnosed few months after support and a tumourectomy with lymphadenectomy was performed. Tumour resection was performed successfully in all patients. Prior to surgery haemostasis, device and heart function were evaluated. During surgery, haemodynamics and anticoagulation were monitored. Reoperations were necessary to evacuate haemothorax after lobectomy and an abdominal haematoma post-nephrectomy. After discussion with oncologists, 3 patients were relisted for heart transplantation. Two were successfully transplanted 2 and 3 years after partial nephrectomy with an actual survival of 56 and 59 months after the cancer diagnosis. The follow-up revealed no cancer recurrences. Malignant tumours during support with LVAD can be successfully resected. A multidisciplinary evaluation in these high-risk patients is mandatory. After careful evaluation, regaining the patient's heart transplant candidacy is possible. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  2. Ventricular Assist Device implant (AB 5000 prototype cannula: In vitro assessment of MRI issues at 3-Tesla

    Directory of Open Access Journals (Sweden)

    Valencerina Samuel

    2008-05-01

    Full Text Available Abstract Purpose To evaluate MRI issues at 3-Tesla for a ventricular assist device (VAD. Methods The AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached (Abiomed, Inc., Danvers, MA was evaluated for magnetic field interactions, heating, and artifacts at 3-Tesla. MRI-related heating was assessed with the device in a gelled-saline-filled, head/torso phantom using a transmit/received RF body coil while performing MRI at a whole body averaged SAR of 3-W/kg for 15-min. Artifacts were assessed for the main metallic component of this VAD (atrial cannula using T1-weighted, spin echo and gradient echo pulse sequences. Results The AB5000 Ventricle with the prototype In-Flow Cannula and Out-Flow Cannula attached showed relatively minor magnetic field interactions that will not cause movement in situ. Heating was not excessive (highest temperature change, +0.8°C. Artifacts may create issues for diagnostic imaging if the area of interest is in the same area or close to the implanted metallic component of this VAD (i.e., the venous cannula. Conclusion The results of this investigation demonstrated that it would be acceptable for a patient with this VAD (AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached to undergo MRI at 3-Tesla or less. Notably, it is likely that the operation console for this device requires positioning a suitable distance (beyond the 100 Gauss line or in the MR control room from the 3-Tesla MR system to ensure proper function of the VAD.

  3. Intelligent speed adaptation as an assistive device for drivers with acquired brain injury: a single-case field experiment.

    Science.gov (United States)

    Klarborg, Brith; Lahrmann, Harry; NielsAgerholm; Tradisauskas, Nerius; Harms, Lisbeth

    2012-09-01

    Intelligent speed adaptation (ISA) was tested as an assistive device for drivers with an acquired brain injury (ABI). The study was part of the "Pay as You Speed" project (PAYS) and used the same equipment and technology as the main study (Lahrmann et al., in press-a, in press-b). Two drivers with ABI were recruited as subjects and had ISA equipment installed in their private vehicle. Their speed was logged with ISA equipment for a total of 30 weeks of which 12 weeks were with an active ISA user interface (6 weeks=Baseline 1; 12 weeks=ISA period; 12 weeks=Baseline 2). The subjects participated in two semi-structured interviews concerning their strategies for driving with ABI and for driving with ISA. Furthermore, they gave consent to have data from their clinical journals and be a part of the study. The two subjects did not report any instances of being distracted or confused by ISA, and in general they described driving with ISA as relaxed. ISA reduced the percentage of the total distance that was driven with a speed above the speed limit (PDA), but the subjects relapsed to their previous PDA level in Baseline 2. This suggests that ISA is more suited as a permanent assistive device (i.e. cognitive prosthesis) than as a temporary training device. As ABI is associated with a multitude of cognitive deficits, we developed a conceptual framework, which focused on the cognitive parameters that have been shown to relate to speeding behaviour, namely "intention to speed" and "inattention to speeding". The subjects' combined status on the two independent parameters made up their "speeding profile". A comparison of the speeding profiles and the speed logs indicated that ISA in the present study was more efficient in reducing inattention to speeding than affecting intention to speed. This finding suggests that ISA might be more suited for some neuropsychological profiles than for others, and that customisation of ISA for different neuropsychological profiles may be required

  4. Manipulation of Self-Assembled Microparticle Chains by Electroosmotic Flow Assisted Electrorotation in an Optoelectronic Device

    Directory of Open Access Journals (Sweden)

    Xiaolu Zhu

    2015-09-01

    Full Text Available A method incorporating the optically induced electrorotation (OER and alternating current electroosmotic (ACEO effects, for the formation and motion control of microparticle chains, is numerically and experimentally demonstrated. In this method, both the rotating electric field and ACEO fluid roll are generated around the border between light and dark area of the fluidic chamber in an optoelectronic tweezers (OET device. The experimental results show that the particle chains can self-rotate in their pitch axes under the rotating electric field produced due to the different impedances of the photoconductive layer in light and dark areas, and have a peak self-rotating rate at around 1 MHz. The orbital movement of entire particle chain around the center of ACEO fluid roll can be achieved from 0.5 to 600 kHz. The strength of OER motion and ACEO-caused orbital movement of particle chains can be adjusted by changing the frequency of alternating current (AC voltage. This non-contact method has the potential for spatially regulating the posture, orientation and position of microparticle chains.

  5. Results of endoscopic vacuum-assisted closure device for treatment of upper GI leaks.

    Science.gov (United States)

    Bludau, Marc; Fuchs, Hans F; Herbold, Till; Maus, Martin K H; Alakus, Hakan; Popp, Felix; Leers, Jessica M; Bruns, Christiane J; Hölscher, Arnulf H; Schröder, Wolfgang; Chon, Seung-Hun

    2018-04-01

    Esophageal perforations and postoperative leakage of esophagogastrostomies are considered to be life-threatening conditions due to the potential development of mediastinitis and consecutive sepsis. Vacuum-assisted closure (VAC) techniques, a well-established treatment method for superficial infected wounds, are based on a negative pressure applied to the wound via a vacuum-sealed sponge. Endoluminal VAC (E-VAC) therapy as a treatment for GI leakages in the rectum was introduced in 2008. E-VAC therapy is a novel method, and experience regarding esophageal applications is limited. In this retrospective study, the experience of a high-volume center for upper GI surgery with E-VAC therapy in patients with leaks of the upper GI tract is summarized. To our knowledge, this series presents the largest patient cohort worldwide in a single-center study. Between October 2010 and January 2017, 77 patients with defects in the upper gastrointestinal tract were treated using the E-VAC application. Six patients had a spontaneous perforation, 12 patients an iatrogenic injury, and 59 patients a postoperative leakage in the upper gastrointestinal tract. Complete restoration of the esophageal defect was achieved in 60 of 77 patients. The average duration of application was 11.0 days, and a median of 2.75 E-VAC systems were used. For 21 of the 77 patients, E-VAC therapy was combined with the placement of self-expanding metal stents. This study demonstrates that E-VAC therapy provides an additional treatment option for esophageal wall defects. Esophageal defects and mediastinal abscesses can be treated with E-VAC therapy where endoscopic stenting may not be possible. A prospective multi-center study has to be directed to bring evidence to the superiority of E-VAC therapy for patients suffering from upper GI defects.

  6. PediaFlow™ Maglev Ventricular Assist Device: A Prescriptive Design Approach.

    Science.gov (United States)

    Antaki, James F; Ricci, Michael R; Verkaik, Josiah E; Snyder, Shaun T; Maul, Timothy M; Kim, Jeongho; Paden, Dave B; Kameneva, Marina V; Paden, Bradley E; Wearden, Peter D; Borovetz, Harvey S

    2010-03-01

    This report describes a multi-disciplinary program to develop a pediatric blood pump, motivated by the critical need to treat infants and young children with congenital and acquired heart diseases. The unique challenges of this patient population require a device with exceptional biocompatibility, miniaturized for implantation up to 6 months. This program implemented a collaborative, prescriptive design process, whereby mathematical models of the governing physics were coupled with numerical optimization to achieve a favorable compromise among several competing design objectives. Computational simulations of fluid dynamics, electromagnetics, and rotordynamics were performed in two stages: first using reduced-order formulations to permit rapid optimization of the key design parameters; followed by rigorous CFD and FEA simulations for calibration, validation, and detailed optimization. Over 20 design configurations were initially considered, leading to three pump topologies, judged on the basis of a multi-component analysis including criteria for anatomic fit, performance, biocompatibility, reliability, and manufacturability. This led to fabrication of a mixed-flow magnetically levitated pump, the PF3, having a displaced volume of 16.6 cc, approximating the size of a AA battery and producing a flow capacity of 0.3-1.5 L/min. Initial in vivo evaluation demonstrated excellent hemocompatibility after 72 days of implantation in an ovine. In summary, combination of prescriptive and heuristic design principles have proven effective in developing a miniature magnetically levitated blood pump with excellent performance and biocompatibility, suitable for integration into chronic circulatory support system for infants and young children; aiming for a clinical trial within 3 years.

  7. Effects of milrinone and epinephrine or dopamine on biventricular function and hemodynamics in right heart failure after pulmonary regurgitation.

    Science.gov (United States)

    Hyldebrandt, Janus Adler; Agger, Peter; Sivén, Eleonora; Wemmelund, Kristian Borup; Heiberg, Johan; Frederiksen, Christian Alcaraz; Ravn, Hanne Berg

    2015-09-01

    Right ventricular failure (RVF) secondary to pulmonary regurgitation (PR) impairs right ventricular (RV) function and interrupts the interventricular relationship. There are few recommendations for the medical management of severe RVF after prolonged PR. PR was induced in 16 Danish landrace pigs by plication of the pulmonary valve leaflets. Twenty-three pigs served as controls. At reexamination the effect of milrinone, epinephrine, and dopamine was evaluated using biventricular conductance and pulmonary catheters. Seventy-nine days after PR was induced, RV end-diastolic volume index (EDVI) had increased by 33% (P = 0.006) and there was a severe decrease in the load-independent measurement of contractility (PRSW) (-58%; P = 0.003). Lower cardiac index (CI) (-28%; P Milrinone improved RV-PRSW and CI and maintained systemic pressure while reducing central venous pressure (CVP). Epinephrine and dopamine further improved biventricular PRSW and CI equally in a dose-dependent manner. Systemic and pulmonary pressures were higher in the dopamine-treated animals compared with epinephrine-treated animals. None of the treatments improved stroke volume index (SVI) despite increases in contractility. Strong correlation was detected between SVI and LV-EDVI, but not SVI and biventricular contractility. In RVF due to PR, milrinone significantly improved CI, SvO2, and CVP and increased contractility in the RV. Epinephrine and dopamine had equal inotropic effect, but a greater vasopressor effect was observed for dopamine. SV was unchanged due to inability of both treatments to increase LV-EDVI. Copyright © 2015 the American Physiological Society.

  8. Assisting the older driver : intersection design and in-car devices to improve the safety of the older driver. Proefschrift Rijksuniversiteit Groningen RUG, Groningen.

    NARCIS (Netherlands)

    Davidse, R.J.

    2007-01-01

    In this thesis, the main focus was on assistive devices that may improve and prolong the safe mobility of older drivers. Older drivers form a group of road users that is getting more and more attention in road safety research and policy. An important reason for this growing interest is the increase

  9. Myocardial fibrosis and pro-fibrotic markers in end-stage heart failure patients during continuous-flow left ventricular assist device support

    NARCIS (Netherlands)

    Lok, Sjoukje I.; Nous, Fay M. A.; van Kuik, Joyce; van der Weide, Petra; Winkens, Bjorn; Kemperman, Hans; Huisman, Andre; Lahpor, Jaap R; de Weger, Roel A.; de Jonge, Nicolaas

    OBJECTIVES: During support with a left ventricular assist device (LVAD), partial reverse remodelling takes place in which fibrosis plays an important role. In this study, we analysed the histological changes and expression of fibrotic markers in patients with advanced heart failure (HF) during

  10. Microwave-assisted extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs) used to indoor air monitoring

    International Nuclear Information System (INIS)

    Esteve-Turrillas, Francesc A.; Pastor, Agustin; Guardia, Miguel de la

    2006-01-01

    A rapid and environmentally friendly methodology was developed for the extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs), in which they were preconcentrated in gas phase. The method was based on gas chromatography mass-mass spectrometry determination after a microwave-assisted extraction, in front of the widely employed dialysis method. SPMDs were extracted twice with 30 mL hexane:acetone, irradiated with 250 W power output, until 90 deg. C in 10 min, this temperature being held for another 10 min. Clean-up of the extracts was performed by acetonitrile-hexane partitioning and solid-phase extraction (SPE) with a combined cartridge of 2 g basic-alumina, deactivated with 5% water, and 500 mg C 18 . Pyrethroids investigated were Allethrin, Prallethrin, Tetramethrin, Bifenthrin, Phenothrin, λ-Cyhalothrin, Permethrin, Cyfluthrin, Cypermethrin, Flucythrinate, Esfenvalerate, Fluvalinate and Deltamethrin. The main pyrethroid synergist compound, Pyperonyl Butoxide, was also studied. Limit of detection values ranging from 0.3 to 0.9 ng/SPMD and repeatability data, as relative standard deviation, from 2.9 to 9.4%, were achieved. Pyrethroid recoveries, for spiked SPMDs, with 100 ng of each one of the pyrethroids evaluated, were from 61 ± 8 to 103 ± 7% for microwave-assisted extraction, versus 54 ± 4 to 104 ± 3% for dialysis reference method. Substantial reduction of solvent consumed (from 400 to 60 mL) and analysis time (from 48 to 1 h) was achieved by using the developed procedure. High concentration levels of pyrethroid compounds, from 0.14 to 7.3 μg/SPMD, were found in indoor air after 2 h of a standard application

  11. Percutaneous excisional biopsy of clinically benign breast lesions with vacuum-assisted system: comparison of three devices.

    Science.gov (United States)

    Wang, Zhi Li; Liu, Gang; Huang, Yan; Wan, Wen Bo; Li, Jun Lai

    2012-04-01

    The aim of this study was to compare three devices in percutaneous excisional biopsy of clinically benign breast lesions in terms of complete excision rate, duration of procedure and complications. In a retrospective study from March 2005 to May 2009, 983 lesions underwent ultrasound-guided excisional biopsy with three vacuum-assisted systems, respectively. The lesions were category 3 lesions as determined by ultrasound imaging according to Breast Imaging Reporting and Data System (BI-RADS) (n=951) or had been confirmed as benign by a previous core needle biopsy (n=32). The completely excision rate, duration of procedure and complications (hematoma, pain and ecchymosis) were recorded. 99.7% (980/983) lesions were demonstrated to be benign by pathology after percutaneous excisional biopsy. The overall complete excision rate was 94.8% (932/983). In lesions whose largest diameter equal to or larger than 1.5cm, the complete excision rates of EnCor(®) group (97.8%, 348/356) and Mammotome(®) group (97.2%, 139/143) were significantly higher than that of Vacora(®) group (91.9%, 445/484) (P<0.05). The EnCor(®) group (6.6±6.5min) had a significant less duration than Mammotome(®) (10.6±9.3min) and Vacora(®) group (25.6±23.3min) (P<0.05). Hematoma occurred more in EnCor(®) group and Mammotome(®) group than in Vacora(®) group (P<0.05). All these three vacuum-assisted systems are highly successful for excisional biopsy of benign breast lesions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Microwave-assisted extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs) used to indoor air monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Esteve-Turrillas, Francesc A. [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain); Pastor, Agustin [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)]. E-mail: agustin.pastor@uv.es; Guardia, Miguel de la [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)

    2006-02-23

    A rapid and environmentally friendly methodology was developed for the extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs), in which they were preconcentrated in gas phase. The method was based on gas chromatography mass-mass spectrometry determination after a microwave-assisted extraction, in front of the widely employed dialysis method. SPMDs were extracted twice with 30 mL hexane:acetone, irradiated with 250 W power output, until 90 deg. C in 10 min, this temperature being held for another 10 min. Clean-up of the extracts was performed by acetonitrile-hexane partitioning and solid-phase extraction (SPE) with a combined cartridge of 2 g basic-alumina, deactivated with 5% water, and 500 mg C{sub 18}. Pyrethroids investigated were Allethrin, Prallethrin, Tetramethrin, Bifenthrin, Phenothrin, {lambda}-Cyhalothrin, Permethrin, Cyfluthrin, Cypermethrin, Flucythrinate, Esfenvalerate, Fluvalinate and Deltamethrin. The main pyrethroid synergist compound, Pyperonyl Butoxide, was also studied. Limit of detection values ranging from 0.3 to 0.9 ng/SPMD and repeatability data, as relative standard deviation, from 2.9 to 9.4%, were achieved. Pyrethroid recoveries, for spiked SPMDs, with 100 ng of each one of the pyrethroids evaluated, were from 61 {+-} 8 to 103 {+-} 7% for microwave-assisted extraction, versus 54 {+-} 4 to 104 {+-} 3% for dialysis reference method. Substantial reduction of solvent consumed (from 400 to 60 mL) and analysis time (from 48 to 1 h) was achieved by using the developed procedure. High concentration levels of pyrethroid compounds, from 0.14 to 7.3 {mu}g/SPMD, were found in indoor air after 2 h of a standard application.

  13. Exploring cognitive bias in destination therapy left ventricular assist device decision making: A retrospective qualitative framework analysis.

    Science.gov (United States)

    Magid, Molly; McIlvennan, Colleen K; Jones, Jaqueline; Nowels, Carolyn T; Allen, Larry A; Thompson, Jocelyn S; Matlock, Dan

    2016-10-01

    Cognitive biases are psychological influences, which cause humans to make decisions, which do not seemingly maximize utility. For people with heart failure, the left ventricular assist device (LVAD) is a surgically implantable device with complex tradeoffs. As such, it represents an excellent model within which to explore cognitive bias in a real-world decision. We conducted a framework analysis to examine for evidence of cognitive bias among people deciding whether or not to get an LVAD. The aim of this study was to explore the influence of cognitive bias on the LVAD decision-making process. We analyzed previously conducted interviews of patients who had either accepted or declined an LVAD using a deductive, predetermined framework of cognitive biases. We coded and analyzed the interviews using an inductive-deductive framework approach, which also allowed for other themes to emerge. We interviewed a total of 22 heart failure patients who had gone through destination therapy LVAD decision making (15 who had accepted the LVAD and 7 who had declined). All patients appeared influenced by state dependence, where both groups described high current state of suffering, but the groups differed in whether they believed LVAD would relieve suffering or not. We found evidence of cognitive bias that appeared to influence decision making in both patient groups, but groups differed in terms of which cognitive biases were present. Among accepters, we found evidence of anchoring bias, availability bias, optimism bias, and affective forecasting. Among decliners, we found evidence of errors in affective forecasting. Medical decision making is often a complicated and multifaceted process that includes cognitive bias as well as other influences. It is important for clinicians to recognize that patients can be affected by cognitive bias, so they can better understand and improve the decision-making process to ensure that patients are fully informed. Published by Elsevier Inc.

  14. Prospective Randomized Evaluation of Implantable Cardioverter-Defibrillator Programming in Patients With a Left Ventricular Assist Device.

    Science.gov (United States)

    Richardson, Travis D; Hale, Leslie; Arteaga, Christopher; Xu, Meng; Keebler, Mary; Schlendorf, Kelly; Danter, Matthew; Shah, Ashish; Lindenfeld, JoAnn; Ellis, Christopher R

    2018-02-23

    Ventricular arrhythmias are common in patients with left ventricular assist devices (LVADs) but are often hemodynamically tolerated. Optimal implantable cardioverter defibrillator (ICD) tachy-programming strategies in patients with LVAD have not been determined. We sought to determine if an ultra-conservative ICD programming strategy in patients with LVAD affects ICD shocks. Adult patients with an existing ICD undergoing continuous flow LVAD implantation were randomized to standard ICD programming by their treating physician or an ultra-conservative ICD programming strategy utilizing maximal allowable intervals to detection in the ventricular fibrillation and ventricular tachycardia zones with use of ATP. Patients with cardiac resynchronization therapy (CRT) devices were also randomized to CRT ON or OFF. Patients were followed a minimum of 6 months. The primary outcome was time to first ICD shock. Among the 83 patients studied, we found no statistically significant difference in time to first ICD shock or total ICD shocks between groups. In the ultra-conservative group 16% of patients experienced at least one shock compared with 21% in the control group ( P =0.66). There was no difference in mortality, arrhythmic hospitalization, or hospitalization for heart failure. In the 41 patients with CRT ICDs fewer shocks were observed with CRT-ON but this was not statistically significant: 10% of patients with CRT-ON (n=21) versus 38% with CRT-OFF (n=20) received shocks ( P =0.08). An ultra-conservative programming strategy did not reduce ICD shocks. Programming restrictions on ventricular tachycardia and ventricular fibrillation zone therapy should be reconsidered for the LVAD population. The role of CRT in patients with LVAD warrants further investigation. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01977703. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  15. Post-transplant outcomes in pediatric ventricular assist device patients: A PediMACS-Pediatric Heart Transplant Study linkage analysis.

    Science.gov (United States)

    Sutcliffe, David L; Pruitt, Elizabeth; Cantor, Ryan S; Godown, Justin; Lane, John; Turrentine, Mark W; Law, Sabrina P; Lantz, Jodie L; Kirklin, James K; Bernstein, Daniel; Blume, Elizabeth D

    2017-12-13

    Pediatric ventricular assist device (VAD) support as bridge to transplant has improved waitlist survival, but the effects of pre-implant status and VAD-related events on post-transplant outcomes have not been assessed. This study is a linkage analysis between the PediMACS and Pediatric Heart Transplant Study databases to determine the effects of VAD course on post-transplant outcomes. Database linkage between October 1, 2012 and December 31, 2015 identified 147 transplanted VAD patients, the primary study group. The comparison cohort was composed of 630 PHTS patients without pre-transplant VAD support. The primary outcome was post-transplant survival, with secondary outcomes of post-transplant length of stay, freedom from infection and freedom from rejection. At implant, the VAD cohort was INTERMACS Profile 1 in 33 (23%), Profile 2 in 89 (63%) and Profile 3 in 14 (10%) patients. The VAD cohort was older, larger, and less likely to have congenital heart disease (p < 0.0001). However, they had greater requirements for inotrope and ventilator support and increased liver and renal dysfunction (p < 0.0001), both of which normalized at transplant after device support. Importantly, there were no differences in 1-year post-transplant survival (96% vs 93%, p = 0.3), freedom from infection (81% vs 79%, p = 0.9) or freedom from rejection (71% vs 74%, p = 0.87) between cohorts. Pediatric VAD patients have post-transplant outcomes equal to that of medically supported patients, despite greater pre-implant illness severity. Post-transplant survival, hospital length of stay, infection and rejection were not affected by patient acuity at VAD implantation or VAD-related complications. Therefore, VAD as bridge to transplant mitigates severity of illness in children. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  16. Comparative analysis of von Willebrand factor profiles after implantation of left ventricular assist device and total artificial heart.

    Science.gov (United States)

    Reich, H J; Morgan, J; Arabia, F; Czer, L; Moriguchi, J; Ramzy, D; Esmailian, F; Lam, L; Dunhill, J; Volod, O

    2017-08-01

    Essentials Bleeding is a major source of morbidity during mechanical circulatory support. von Willebrand factor (VWF) multimer loss may contribute to bleeding. Different patterns of VWF multimer loss were seen with the two device types. This is the first report of total artificial heart associated VWF multimer loss. Background Bleeding remains a challenge during mechanical circulatory support and underlying mechanisms are incompletely understood. Functional von Willebrand factor (VWF) impairment because of loss of high-molecular-weight multimers (MWMs) produces acquired von Willebrand disease (VWD) after left ventricular assist device (LVAD). Little is known about VWF multimers with total artificial hearts (TAHs). Here, VWF profiles with LVADs and TAHs are compared using a VWD panel. Methods VWD evaluations for patients with LVAD or TAH (2013-14) were retrospectively analyzed and included: VWF activity (ristocetin cofactor, VWF:RCo), VWF antigen (VWF:Ag), ratio of VWF:RCo to VWF:Ag, and quantitative VWF multimeric analysis. Results Twelve patients with LVADs and 12 with TAHs underwent VWD evaluation. All had either normal (47.8%) or elevated (52.2%) VWF:RCo, normal (26.1%) or elevated (73.9%) VWF:Ag and 50.0% were disproportional (ratio ≤ 0.7). Multimeric analysis showed abnormal patterns in all patients with LVADs: seven with high MWM loss; five with highest MWM loss. With TAH, 10/12 patients had abnormal patterns: all with highest MWM loss. High MWM loss correlated with presence of LVAD and highest MWM loss with TAH. Increased low MWMs were detected in 22/24. Conclusion Using VWF multimeric analysis, abnormalities after LVAD or TAH were detected that would be missed with measurements of VWF level alone: loss of high MWM predominantly in LVAD, loss of highest MWM in TAH, and elevated levels of low MWM in both. This is the first study to describe TAH-associated highest MWM loss, which may contribute to bleeding. © 2017 International Society on Thrombosis and

  17. Modification of self-concept in patients with a left-ventricular assist device: an initial exploration.

    Science.gov (United States)

    Marcuccilli, Linda; Casida, Jesus; Peters, Rosalind M

    2013-09-01

    To explore how patients with left-ventricular assist devices (LVAD) meet the health-deviation requisite of modifying self-concept to accept this form of treatment and restore normalcy. LVAD are becoming a standard option to improve the quality of life for patients with advanced heart failure. Past research focused on technology issues and survival rates, but limited research has addressed the effect of LVADs on patients' perceptions of self. Orem's theory of self-care provides a framework to investigate how patients manage threats to self-concept to safely live with such a device. Hermeneutic phenomenology based on van Manen's method. Data were collected using semi-structured interviews. Data saturation was achieved with nine participants (seven men; two women), 31-70 years of age who lived with a LVAD at home for at least three months. Thematic analysis was ongoing, and final themes were consensually validated. Two themes constructed from the data were consistent with the requisite of modifying self-concept. First, Having a LVAD means living. Participants described they 'feel alive again', and they 'had the rest of [their] lives that they didn't have before'. The second theme: A desire to be 'normal' in public, arose from participants descriptions of how the LVAD brought unwanted attention to them and that their appearance was 'shocking' to others. Participants accepted the LVAD as necessary to live making it easier for them to modify their self-concept and accept the changes to their bodies and daily lives. Attaining a sense of normalcy was more difficult in public and required additional lifestyle modifications. Findings advance self-care knowledge in LVAD management and can heighten nurses' awareness about self-concept as a vital component for maintenance of health and well-being. © 2013 Blackwell Publishing Ltd.

  18. Critically Underdeveloped Left Heart Morphology Associated with Prematurity and Low Birth Weight: Conditional Staged Rehabilitation Towards Biventricular Repair and Time-Related Growth of Left Heart Structures.

    Science.gov (United States)

    Ahmad, Fareed; Mangano, Robert; Shore, Shirah; Polimenakos, Anastasios

    2017-10-01

    This is a case report of premature low birth weight infant with hypoplasia of left heart structures and a large malaligned VSD who underwent successful staged approach of biventricular repair. We obtained qualitative and quantitative echocardiographic, MRI, and conventional catheterization data to support stepwise strategy towards LV rehabilitation to sustain adequate cardiac output. A thorough and intense follow-up has shown significant growth of left heart structures and favorable clinical status following staged biventricular repair. Our data indicate usefulness of qualitative and quantitative advanced complimentary multi-imaging modalities in predicting the postnatal growth potential of critically underdeveloped left heart structures.

  19. Social Support Moderates the Relationship Between Perceived Stress and Quality of Life in Patients With a Left Ventricular Assist Device.

    Science.gov (United States)

    Abshire, Martha; Russell, Stuart D; Davidson, Patricia M; Budhathoki, Chakra; Han, Hae-Ra; Grady, Kathleen L; Desai, Shashank; Dennison Himmelfarb, Cheryl

    2018-04-20

    Living with a left ventricular assist device has significant psychosocial sequelae that affect health-related quality of life (HRQOL). The purpose of this study was to (1) describe psychosocial indicators of stress including perceived stress, depression, fatigue, and coping; (2) examine relationships among stress indicators by level of perceived stress; (3) examine relationships among indicators of stress and clinical outcomes; and (4) test the moderation of social support on the relationship between stress and clinical outcomes. Participants were recruited from 2 outpatient clinics in a cross-sectional study design. Standardized measures were self-administered via survey. Descriptive statistics, correlation, and multiple linear regression analysis were conducted. The sample (N = 62) was mostly male (78%), black (47%), and married (66%), with a mean age of 56.5 ± 13 years. The overall sample had a moderate stress profile: moderate perceived stress (mean, 11.7 ± 7), few depressive symptoms (mean, 3.2 ± 3.9), and moderate fatigue (mean, 14.3 ± 9.1). Increased perceived stress was associated with fatigue, depressive symptoms, and maladaptive coping (P stress and fatigue were significant correlates of overall HRQOL (adj. R = 0.41, P relationship between perceived stress and HRQOL, controlling for fatigue (R = 0.49, P stress have worse depressive symptoms, fatigue, and coping. The influence of high social support to improve the relationship between stress and HRQOL underscores the importance of a comprehensive plan to address psychosocial factors.

  20. Preliminary design of the internal geometry in a minimally invasive left ventricular assist device under pulsatile-flow conditions.

    Science.gov (United States)

    Smith, P Alex; Wang, Yaxin; Metcalfe, Ralph W; Sampaio, Luiz C; Timms, Daniel L; Cohn, William E; Frazier, O H

    2018-03-01

    A minimally invasive, partial-assist, intra-atrial blood pump has been proposed, which would unload the left ventricle with a flow path from the left atrium to the arterial system. Flow modulation is a common strategy for ensuring washout in the pump, but it can increase power consumption because it is typically achieved through motor-speed variation. However, if a pump's performance curve had the proper gradient, flow modulation could be realized passively. To achieve this goal, we propose a pump performance operating curve as an alternative to the more standard operating point. Mean-line theory was employed to generate an initial set of geometries that were then tested on a hydraulic test rig at ~20,000 r/min. Experimental results show that the intra-atrial blood pump performed below the operating region; however, it was determined that smaller hub diameter and longer chord length bring the performance of the intra-atrial blood pump device closer to the operating curve. We found that it is possible to shape the pump performance curve for specifically targeted gradients over the operating region through geometric variations inside the pump.

  1. Construction of bioartificial renal tubule assist device in vitro and its function of transporting sodium and glucose.

    Science.gov (United States)

    Dong, Xinggang; Chen, Jianghua; He, Qiang; Yang, Yi; Zhang, Wei

    2009-08-01

    To explore a new way of constructing bioartificial renal tubule assist device (RAD) in vitro and its function of transporting sodium (Na(+)) and glucose and to evaluate the application of atomic force microscope in the RAD construction, rat renal tubular epithelial cell line NRK-52E was cultured in vitro, seeded onto the outer surfaces of hollow fibers in a bioreactor, and then cultured for two weeks to construct RAD. Bioreactor hollow fibers without NRK-52E cells were used as control. The morphologies of attached cells were observed with scanning electron microscope, and the junctions of cells and polysulfone membrane were observed with atomic force microscope. Transportation of Na(+) and glucose was measured. Oubaine and phlorizin were used to inhibit the transporting property. The results showed that NRK-52E cells and polysulfone membrane were closely linked, as observed under atomic force microscope. After exposure to oubaine and phlorizin, transporting rates of Na(+) and glucose were decreased significantly in the RAD group as compared with that in the control group (Pconstructed successfully in vitro, and it is able to selectively transport Na(+) and glucose.

  2. The miRNA Expression Profile in Acute Myocardial Infarct Using Sheep Model with Left Ventricular Assist Device Unloading

    Directory of Open Access Journals (Sweden)

    Xiaoqian Yan

    2017-01-01

    Full Text Available This study attempted to establish miRNA expression profiles in acute myocardial infarct (AMI sheep model with left ventricular assist device (LVAD unloading. AMI was established in sheep model and FW-II type axial flow pump was implanted to maintain continuous unloading for 3 days. The cardiomyocyte survival, inflammatory cell infiltration, and myocardial fibrosis were detected by tissue staining, and cardiomyocyte apoptosis was detected by TUNEL assay. High throughput sequencing technique was used to detect miRNA expression in cardiomyocytes and to establish miRNA expression profile. The Gene Ontology (GO and Kyoto Encyclopedia of Genes and Genomes (KEGG analyses were established. miRNA sequencing results identified 152 known mature miRNAs and 1582 new mature miRNAs. The unloading and control groups differentially expressed genes, of which RT-PCR verified oar-miR-19b and oar-miR-26a. The GO and KEGG pathway annotation and enrichment established that the regulating functions and signaling pathways of these miRNAs were closely related to cardiovascular diseases (CVD. In this study, LVAD effectively reduced the cell death degree of cardiomyocyte in MI. The established miRNA expression profiles of AMI and LVAD intervention in this study suggest that the expression profile could be used to explore the unknown miRNA and the regulatory mechanisms involved in AMI.

  3. Exertional Angina Due To Fused Aortic Bioprosthesis During Left Ventricular Assist Device Support: Two Cases and Review of the Literature.

    Science.gov (United States)

    Bonios, Michael J; Selzman, Craig H; Gilbert, Edward M; McKellar, Stephen H; Koliopoulou, Antigoni; Strege, Jennifer L; Nativi, Jose N; Fang, James C; Stehlik, Josef; Drakos, Stavros G

    We present the case of two patients with idiopathic dilated cardiomyopathy and moderate aortic valve regurgitation that were treated with a bioprosthetic valve at the time of the left ventricular assist device (LVAD) implantation. A few months later, patients revealed partial recovery in the left ventricle systolic function. Both patients, during the LVAD turndown protocol, reported the onset of chest pain. The transthoracic echocardiography revealed the presence of a new transaortic pressure gradient. We confirmed the presence of a fused bioprosthetic valve by further performing a transesophageal echocardiogram and a left and right heart catheterization. Replacement of aortic valve at the time of an LVAD implantation constitutes a challenging case. Although a mechanical valve is contraindicated due to the increased thromboembolic risk, selecting a bioprosthetic valve increases the risk of valve leaflets fusion. The consequences of this phenomenon should be acknowledged in LVAD patients undergoing aortic valve replacement with a bioprosthetic, especially under the view of LVAD explantation for those revealing myocardial recovery under mechanical unloading.

  4. Flow visualization of a monoleaflet and bileaflet mechanical heart valve in a pneumatic ventricular assist device using a PIV system.

    Science.gov (United States)

    Lee, Hwansung; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2010-01-01

    Our group is developing a new type of pulsatile pneumatic ventricular assist device (PVAD) that uses the Medtronic Hall tilting disc valve (M-H valve). Although tilting disc valves have good washout effect inside the blood pump, they are no longer in common clinical use and may be difficult to obtain in the future. To investigate the stability of the Sorin Bicarbon valve (S-B valve) in our PVAD, we constructed a model pump made of an acrylic resin with the same configuration as our PVAD and attempted to compare the flow visualization upstream and downstream of the outlet position valve between the M-H valve and the S-B valve using a particle image velocimetry (PIV) method. The outlet S-B valve had faster closure than the M-H valve. The maximum flow velocity was greater than with the M-H valve. The maximum Reynolds shear stress (RSS) of the M-H valve reached 150 N/m(2) and that of the S-B valve reached 300 N/m(2) upstream during the end-systolic and early-diastolic phases. In both valves, the maximum RSS upstream of the valve was higher than downstream of the valve because of the regurgitation flow during valve closure. In addition, the maximum viscous shear stress reached above 2 N/m(2), which occupied only about 1%-1.5% of the maximum RSS.

  5. [Improvement of biventricular heart failure in a case of obstructive sleep apnea syndrome by nasal CPAP therapy].

    Science.gov (United States)

    Yamamoto, H; Akashiba, T; Minemura, H; Kurashina, K; Yoshizawa, T; Otsuka, K; Horie, T

    1993-08-01

    A 42-year-old male patient with obstructive sleep apnea syndrome (OSAS) suffering from biventricular heart failure is reported. He had been treated for OSAS with conventional therapy. However, he complained of severe dyspnea in association with extreme weight gain and general edema. Therefore, he was admitted to our department. He weighed 168 kg on admission, and marked edema was observed. Chest film revealed significant dilatation of the cardiac silhouette and pleural effusion. PaO2 was 37 mmHg and PaCO2 was 66 mmHg. Polysomnography showed an apnea index of 58.3 and severe oxygen desaturation during sleep. Right heart catheterization showed elevation of mean pulmonary artery pressure mPAP: 55 mmHg) and pulmonary capillary wedge pressure (Pcwp: 33 mmHg) suggesting biventricular heart failure. Digitalization and diuretic therapy were immediately initiated. In addition, nasal CPAP was applied to this patient during sleep, and sleep apnea and oxygen desaturation were almost completely reversed. Significant diuresis was observed, and blood gas data and sleep disturbance were improved. Fifty-nine days after admission, his weight had decreased to 96 kg, and mPAP and Pcwp decreased to 32 and 23 mmHg, respectively. This case demonstrates that nasal CPA is an effective tool for the treatment severe OSAS patients.

  6. Left Ventricular Function Improves after Pulmonary Valve Replacement in Patients with Previous Right Ventricular Outflow Tract Reconstruction and Biventricular Dysfunction

    Science.gov (United States)

    Kane, Colin; Kogon, Brian; Pernetz, Maria; McConnell, Michael; Kirshbom, Paul; Rodby, Katherine; Book, Wendy M.

    2011-01-01

    Congenital heart defects that have a component of right ventricular outflow tract obstruction, such as tetralogy of Fallot, are frequently palliated in childhood by disruption of the pulmonary valve. Although this can provide an initial improvement in quality of life, these patients are often left with severe pulmonary valve insufficiency. Over time, this insufficiency can lead to enlargement of the right ventricle and to the deterioration of right ventricular systolic and diastolic function. Pulmonary valve replacement in these patients decreases right ventricular volume overload and improves right ventricular performance. To date, few studies have examined the effects of pulmonary valve replacement on left ventricular function in patients with biventricular dysfunction. We sought to perform such an evaluation. Records of adult patients who had undergone pulmonary valve replacement from January 2003 through November 2006 were analyzed retrospectively. We reviewed preoperative and postoperative echocardiograms and calculated left ventricular function in 38 patients. In the entire cohort, the mean left ventricular ejection fraction increased by a mean of 0.07 after pulmonary valve replacement, which was a statistically significant change (P < 0.01). In patients with preoperative ejection fractions of less than 0.50, mean ejection fractions increased by 0.10. We conclude that pulmonary valve replacement in patients with biventricular dysfunction arising from severe pulmonary insufficiency and right ventricular enlargement can improve left ventricular function. Prospective studies are needed to verify this finding. PMID:21720459

  7. EQUIPO PORTATIL PARA ASISTIR LA COSECHA MANUAL DE CAFE PORTABLE DEVICE TO ASSIST MANUAL HARVESTING OF COFFEE

    Directory of Open Access Journals (Sweden)

    Carlos Eugenio Oliveros Tascón

    2005-12-01

    -weight portable device was developed to assist manual harvesting of coffee. The device, driven by an 84,7 W DC motor, consisted of a 0,85 kg actuator carried in the operator’s hand and an 8 kg back-mounted frame to carry the batteries. Two rotating beaters made of Teflon, turning at 1.100 rpm, detach the fruits. With the new device it is possible to obtain massive detachment in clusters with high concentrations of mature fruits, avoiding the “fruit grabbing” which demands 40 % of the time needed in a manual harvesting cycle. The inertia of the motor and the mechanism is enough to detach up to 4 fruits after turning the device off. The device, called IMFRA 3DC (stands for the spanish words “IMpactador de FRutos” - fruit beater artifact, was evaluated in Timbío ( Cauca, Colombia , in the main harvesting season of 2004. The evaluation was conducted in a plantation with 2-year old coffee trees of the Red Colombia variety. The trees were planted in a 1,5 m x 1,0 m pattern, in flat terrain, and each tree had two stems. The average mature fruit charge and concentration were 1,43 kg and 80,7 %, respectively. With the device, a net yield of 33,7 kg/h per operator was obtained, almost three times greater than that observed in traditional hand picking. The harvesting quality improved conspicuously when the operators were more familiar with the apparatus; the first day they harvested 10,3 % of immature fruits and the fourth day they harvested just 4,3 %. The effectiveness was close to 80 %, which is acceptable when an additional harvesting pass is required. The results obtained indicate that the IMFRA 3DC is a promissing tool to assist in manual harvesting in high-density coffee plantations and to reduce production costs.

  8. Exploration of Two Training Paradigms Using Forced Induced Weight Shifting With the Tethered Pelvic Assist Device to Reduce Asymmetry in Individuals After Stroke: Case Reports.

    Science.gov (United States)

    Bishop, Lauri; Khan, Moiz; Martelli, Dario; Quinn, Lori; Stein, Joel; Agrawal, Sunil

    2017-10-01

    Many robotic devices in rehabilitation incorporate an assist-as-needed haptic guidance paradigm to promote training. This error reduction model, while beneficial for skill acquisition, could be detrimental for long-term retention. Error augmentation (EA) models have been explored as alternatives. A robotic Tethered Pelvic Assist Device has been developed to study force application to the pelvis on gait and was used here to induce weight shift onto the paretic (error reduction) or nonparetic (error augmentation) limb during treadmill training. The purpose of these case reports is to examine effects of training with these two paradigms to reduce load force asymmetry during gait in two individuals after stroke (>6 mos). Participants presented with baseline gait asymmetry, although independent community ambulators. Participants underwent 1-hr trainings for 3 days using either the error reduction or error augmentation model. Outcomes included the Borg rating of perceived exertion scale for treatment tolerance and measures of force and stance symmetry. Both participants tolerated training. Force symmetry (measured on treadmill) improved from pretraining to posttraining (36.58% and 14.64% gains), however, with limited transfer to overground gait measures (stance symmetry gains of 9.74% and 16.21%). Training with the Tethered Pelvic Assist Device device proved feasible to improve force symmetry on the treadmill irrespective of training model. Future work should consider methods to increase transfer to overground gait.

  9. Extracorporeal liver assist device to exchange albumin and remove endotoxin in acute liver failure: Results of a pivotal pre-clinical study.

    Science.gov (United States)

    Lee, Karla C L; Baker, Luisa A; Stanzani, Giacomo; Alibhai, Hatim; Chang, Yu Mei; Jimenez Palacios, Carolina; Leckie, Pamela J; Giordano, Paola; Priestnall, Simon L; Antoine, Daniel J; Jenkins, Rosalind E; Goldring, Christopher E; Park, B Kevin; Andreola, Fausto; Agarwal, Banwari; Mookerjee, Rajeshwar P; Davies, Nathan A; Jalan, Rajiv

    2015-09-01

    In acute liver failure, severity of liver injury and clinical progression of disease are in part consequent upon activation of the innate immune system. Endotoxaemia contributes to innate immune system activation and the detoxifying function of albumin, critical to recovery from liver injury, is irreversibly destroyed in acute liver failure. University College London-Liver Dialysis Device is a novel artificial extracorporeal liver assist device, which is used with albumin infusion, to achieve removal and replacement of dysfunctional albumin and reduction in endotoxaemia. We aimed to test the effect of this device on survival in a pig model of acetaminophen-induced acute liver failure. Pigs were randomised to three groups: Acetaminophen plus University College London-Liver Dialysis Device (n=9); Acetaminophen plus Control Device (n=7); and Control plus Control Device (n=4). Device treatment was initiated two h after onset of irreversible acute liver failure. The Liver Dialysis Device resulted in 67% reduced risk of death in acetaminophen-induced acute liver failure compared to Control Device (hazard ratio=0.33, p=0.0439). This was associated with 27% decrease in circulating irreversibly oxidised human non-mercaptalbumin-2 throughout treatment (p=0.046); 54% reduction in overall severity of endotoxaemia (p=0.024); delay in development of vasoplegia and acute lung injury; and delay in systemic activation of the TLR4 signalling pathway. Liver Dialysis Device-associated adverse clinical effects were not seen. The survival benefit and lack of adverse effects would support clinical trials of University College London-Liver Dialysis Device in acute liver failure patients. Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  10. Intraoperative Hemodynamic and Echocardiographic Measurements Associated With Severe Right Ventricular Failure After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Gudejko, Michael D; Gebhardt, Brian R; Zahedi, Farhad; Jain, Ankit; Breeze, Janis L; Lawrence, Matthew R; Shernan, Stanton K; Kapur, Navin K; Kiernan, Michael S; Couper, Greg; Cobey, Frederick C

    2018-06-05

    Severe right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation increases morbidity and mortality. We investigated the association between intraoperative right heart hemodynamic data, echocardiographic parameters, and severe versus nonsevere RVF. A review of LVAD patients between March 2013 and March 2016 was performed. Severe RVF was defined by the need for a right ventricular mechanical support device, inotropic, and/or inhaled pulmonary vasodilator requirements for >14 days. From a chart review, the right ventricular failure risk score was calculated and right heart hemodynamic data were collected. Pulmonary artery pulsatility index (PAPi) [(pulmonary artery systolic pressure - pulmonary artery diastolic pressure)/central venous pressure (CVP)] was calculated for 2 periods: (1) 30 minutes before cardiopulmonary bypass (CPB) and (2) after chest closure. Echocardiographic data were recorded pre-CPB and post-CPB by a blinded reviewer. Univariate logistic regression models were used to examine the performance of hemodynamic and echocardiographic metrics. A total of 110 LVAD patients were identified. Twenty-five did not meet criteria for RVF. Of the remaining 85 patients, 28 (33%) met criteria for severe RVF. Hemodynamic factors associated with severe RVF included: higher CVP values after chest closure (18 ± 9 vs 13 ± 5 mm Hg; P = .0008) in addition to lower PAPi pre-CPB (1.2 ± 0.6 vs 1.7 ± 1.0; P = .04) and after chest closure (0.9 ± 0.5 vs 1.5 ± 0.8; P = .0008). Post-CPB echocardiographic findings associated with severe RVF included: larger right atrial diameter major axis (5.4 ± 0.9 vs 4.9 ± 1.0 cm; P = .03), larger right ventricle end-systolic area (22.6 ± 8.4 vs 18.5 ± 7.9 cm; P = .03), lower fractional area of change (20.2 ± 10.8 vs 25.9 ± 12.6; P = .04), and lower tricuspid annular plane systolic excursion (0.9 ± 0.2 vs 1.1 ± 0.3 cm; P = .008). Right ventricular failure risk score was not a significant predictor of

  11. Exercise physiology with a left ventricular assist device: Analysis of heart-pump interaction with a computational simulator.

    Science.gov (United States)

    Fresiello, Libera; Rademakers, Frank; Claus, Piet; Ferrari, Gianfranco; Di Molfetta, Arianna; Meyns, Bart

    2017-01-01

    Patients with a Ventricular Assist Device (VAD) are hemodynamically stable but show an impaired exercise capacity. Aim of this work is to identify and to describe the limiting factors of exercise physiology with a VAD. We searched for data concerning exercise in heart failure condition and after VAD implantation from the literature. Data were analyzed by using a cardiorespiratory simulator that worked as a collector of inputs coming from different papers. As a preliminary step the simulator was used to reproduce the evolution of hemodynamics from rest to peak exercise (ergometer cycling) in heart failure condition. Results evidence an increase of cardiac output of +2.8 l/min and a heart rate increase to 67% of the expected value. Then, we simulated the effect of a continuous-flow VAD at both rest and exercise. Total cardiac output increases of +3.0 l/min (+0.9 l/min due to the VAD and +2.1 l/min to the native ventricle). Since the left ventricle works in a non-linear portion of the diastolic stiffness line, we observed a consistent increase of pulmonary capillary wedge pressure (from 14 to 20 mmHg) for a relatively small increase of end-diastolic volume (from 182 to 189 cm3). We finally increased VAD speed during exercise to the maximum possible value and we observed a reduction of wedge pressure (-4.5 mmHg), a slight improvement of cardiac output (8.0 l/min) and a complete unloading of the native ventricle. The VAD can assure a proper hemodynamics at rest, but provides an insufficient unloading of the left ventricle and does not prevent wedge pressure from rising during exercise. Neither the VAD provides major benefits during exercise in terms of total cardiac output, which increases to a similar extend to an unassisted heart failure condition. VAD speed modulation can contribute to better unload the ventricle but the maximal flow reachable with the current devices is below the cardiac output observed in a healthy heart.

  12. Right ventricular dysfunction following continuous flow left ventriccular assist device placement in 51 patients: predicators and outcomes

    Directory of Open Access Journals (Sweden)

    Neragi-Miandoab Siyamek

    2012-06-01

    Full Text Available Abstract Background Right ventricular (RV dysfunction following implantation of a left ventricular assist device (LVAD is a serious condition and is associated with increased mortality. Methods The aim of the study is to investigate the significance of pre-existing RV dysfunction, tricuspid valve (TV insufficiency, and the severity of septal deviation following LVAD implantation on RV dysfunction, as well as the outcome and short-term complications in 51 patients from June 2006 to August 2010. Student t test was used to compare the data and estimate the p value. Results Mean age was 55.1 ± 13, with a male to female ratio of 3.25. The 30-day mortality was 13.7% (7/51 patients, and the overall mortality was 23.5% (12/51 patients. Meanwhile, 21 patients (21/51; 41.2% have undergone orthotopic heart transplantation. The mean time of support was 314.5±235 days with a median of 240 days at the time of closing this study. Echocardiographic evaluation of RV function pre- and post-implantation of an LVAD demonstrated septal deviation towards the left ventricle in immediate postoperative phase, which correlated with acute RV dysfunction (p = 0.002. Preoperative RV dysfunction was a significant predictor of postoperative right heart dysfunction following implantation of an LVAD (p = 0.001. Conclusion Preoperative RV dysfunction is a predictor of RV failure in LVAD patients. The adjustment of septal deviation through gradual increase of the LVAD flow can prevent the acute RV dysfunction following LVAD placement.

  13. Impact of ventricular assist device placement on longitudinal renal function in children with end-stage heart failure.

    Science.gov (United States)

    May, Lindsay J; Montez-Rath, Maria E; Yeh, Justin; Axelrod, David M; Chen, Sharon; Maeda, Katsuhide; Almond, Christopher S D; Rosenthal, David N; Hollander, Seth A; Sutherland, Scott M

    2016-04-01

    Although ventricular assist devices (VADs) restore hemodynamics in those with heart failure, reversibility of end-organ dysfunction with VAD support is not well characterized. Renal function often improves in adults after VAD placement, but this has not been comprehensively explored in children. Sixty-three children on VAD support were studied. Acute kidney injury (AKI) was defined by Kidney Disease: Improving Global Outcomes criteria. Estimated glomerular filtration rate (eGFR) was determined by the Schwartz method. Generalized linear mixed-effects models compared the pre-VAD and post-VAD eGFR for the cohort and sub-groups with and without pre-VAD renal dysfunction (pre-VAD eGFR renal dysfunction. AKI affected 60.3% (38 of 63), with similar rates in those with and without pre-existing renal dysfunction. Within the cohort, the nadir eGFR occurred 1 day post-operatively (62.9 ml/min/1.73 m(2); IQR, 51.2-88.9 ml/min/1.73 m(2); p renal dysfunction experienced the greatest improvement in the eGFR (β = 0.0051 vs β = 0.0013, p Renal dysfunction is prevalent in children with heart failure undergoing VAD placement. Although peri-operative AKI is common, renal function improves substantially in the first post-operative week and for months thereafter. This is particularly pronounced in those with pre-VAD renal impairment, suggesting that VADs may facilitate recovery and maintenance of kidney function in children with advanced heart failure. Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  14. Single axis controlled hybrid magnetic bearing for left ventricular assist device: hybrid core and closed magnetic circuit.

    Science.gov (United States)

    da Silva, Isaias; Horikawa, Oswaldo; Cardoso, Jose R; Camargo, Fernando A; Andrade, Aron J P; Bock, Eduardo G P

    2011-05-01

    In previous studies, we presented main strategies for suspending the rotor of a mixed-flow type (centrifugal and axial) ventricular assist device (VAD), originally presented by the Institute Dante Pazzanese of Cardiology (IDPC), Brazil. Magnetic suspension is achieved by the use of a magnetic bearing architecture in which the active control is executed in only one degree of freedom, in the axial direction of the rotor. Remaining degrees of freedom, excepting the rotation, are restricted only by the attraction force between pairs of permanent magnets. This study is part of a joint project in development by IDPC and Escola Politecnica of São Paulo University, Brazil. This article shows advances in that project, presenting two promising solutions for magnetic bearings. One solution uses hybrid cores as electromagnetic actuators, that is, cores that combine iron and permanent magnets. The other solution uses actuators, also of hybrid type, but with the magnetic circuit closed by an iron core. After preliminary analysis, a pump prototype has been developed for each solution and has been tested. For each prototype, a brushless DC motor has been developed as the rotor driver. Each solution was evaluated by in vitro experiments and guidelines are extracted for future improvements. Tests have shown good results and demonstrated that one solution is not isolated from the other. One complements the other for the development of a single-axis-controlled, hybrid-type magnetic bearing for a mixed-flow type VAD. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  15. The effect of heart failure and left ventricular assist device treatment on right ventricular mechanics: a computational study.

    Science.gov (United States)

    Park, Jun I K; Heikhmakhtiar, Aulia Khamas; Kim, Chang Hyun; Kim, Yoo Seok; Choi, Seong Wook; Song, Kwang Soup; Lim, Ki Moo

    2018-05-22

    Although it is important to analyze the hemodynamic factors related to the right ventricle (RV) after left ventricular assist device (LVAD) implantation, previous studies have focused only on the alteration of the ventricular shape and lack quantitative analysis of the various hemodynamic parameters. Therefore, we quantitatively analyzed various hemodynamic parameters related to the RV under normal, heart failure (HF), and HF incorporated with continuous flow LVAD therapy by using a computational model. In this study, we combined a three-dimensional finite element electromechanical model of ventricles, which is based on human ventricular morphology captured by magnetic resonance imaging (MRI) with a lumped model of the circulatory system and continuous flow LVAD function in order to construct an integrated model of an LVAD implanted-cardiovascular system. To induce systolic dysfunction, the magnitude of the calcium transient function under HF condition was reduced to 70% of the normal value, and the time constant was reduced by 30% of the normal value. Under the HF condition, the left ventricular end systolic pressure decreased, the left ventricular end diastolic pressure increased, and the pressure in the right atrium (RA), RV, and pulmonary artery (PA) increased compared with the normal condition. The LVAD therapy decreased the end-systolic pressure of the LV by 41%, RA by 29%, RV by 53%, and PA by 71%, but increased the right ventricular ejection fraction by 52% and cardiac output by 40%, while the stroke work was reduced by 67% compared with the HF condition without LVAD. The end-systolic ventricular tension and strain decreased with the LVAD treatment. LVAD enhances CO and mechanical unloading of the LV as well as those of the RV and prevents pulmonary hypertension which can be induced by HF.

  16. Usefulness of Tricuspid Annular Diameter to Predict Late Right Sided Heart Failure in Patients With Left Ventricular Assist Device.

    Science.gov (United States)

    Nakanishi, Koki; Homma, Shunichi; Han, Jiho; Takayama, Hiroo; Colombo, Paolo C; Yuzefpolskaya, Melana; Garan, Arthur R; Farr, Maryjane A; Kurlansky, Paul; Di Tullio, Marco R; Naka, Yoshifumi; Takeda, Koji

    2018-07-01

    Although late-onset right-sided heart failure is recognized as a clinical problem in the treatment of patients with left ventricular assist devices (LVADs), the mechanism and predictors are unknown. Tricuspid valve (TV) deformation leads to the restriction of the leaflet motion and decreased coaptation, resulting in a functional tricuspid regurgitation that may act as a surrogate marker of late right-sided heart failure. This study aimed to investigate the association of preoperative TV deformation (annulus dilatation and leaflet tethering) with late right-sided heart failure development after continuous-flow LVAD implantation. The study cohort consisted of 274 patients who underwent 2-dimensional echocardiography before LVAD implantation. TV annulus diameter and tethering distance were measured in an apical 4-chamber view. Late right-sided heart failure was defined as right-sided heart failure requiring readmission and medical and/or surgical treatment after initial LVAD implantation. During a mean follow-up of 25.1 ± 19.0 months after LVAD implantation, late right-sided heart failure occurred in 33 patients (12.0%). Multivariate Cox proportional hazard analysis demonstrated that TV annulus diameter (hazard ratio 1.221 per 1 mm, p right-sided heart failure development, whereas leaflet tethering distance was not. The best cut-off value of the TV annular diameter was 41 mm (area under the curve 0.787). Kaplan-Meier analysis showed that patients with dilated TV annulus (TV annular diameter ≥41 mm) exhibited a significantly higher late right-sided heart failure occurrence than those without TV annular enlargement (log-rank p right-sided heart failure after LVAD implantation. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Multicentre clinical trial experience with the HeartMate 3 left ventricular assist device: 30-day outcomes.

    Science.gov (United States)

    Zimpfer, Daniel; Netuka, Ivan; Schmitto, Jan D; Pya, Yuriy; Garbade, Jens; Morshuis, Michiel; Beyersdorf, Friedhelm; Marasco, Silvana; Rao, Vivek; Damme, Laura; Sood, Poornima; Krabatsch, Thomas

    2016-09-01

    The objective of this study was to describe the operative experience and 30-day outcomes of patients implanted with the HeartMate 3 Left Ventricular Assist System (LVAS) during the Conformité Européenne (CE) Mark clinical trial. Adult patients met inclusion and exclusion criteria defining advanced-stage heart failure and included the indications of bridge to transplant and destination therapy. Operative parameters, outcomes, adverse events, physical status and quality-of-life parameters were assessed in the first 30 days after LVAS implant. Fifty patients were implanted with the HeartMate 3 at 10 centres in 6 countries. The 30-day survival rate was 98%. The median operative and cardiopulmonary bypass times were 200 (range: 95-585) min and 84 (range: 47-250) min, respectively. Patients required transfusion with packed red blood cells (3.6 ± 2.3 units), fresh frozen plasma (6.5 ± 5 units) and platelets (2 ± 1 units). Six patients (12%) required reoperation for postoperative bleeding and 10 patients (20%) did not require blood transfusion. The median intensive care time was 6 days (range: 1-112 days) and the total hospital stay was 28 days (range: 14-116 days). The most common adverse events were bleeding (15, 30%), arrhythmia (14, 28%) and infection (10, 20%). There were 2 (4%) strokes. The 30-day outcomes following implantation of the HeartMate 3 demonstrates excellent survival with low adverse event rates. The LVAD performed as intended with no haemolysis or device failure. NCT02170363. HeartMate 3™ CE Mark Clinical Investigation Plan (HM3 CE Mark). © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  18. Postoperative B-Type Natriuretic Peptide as Predictor for Postoperative Outcomes in Patients Implanted With Left Ventricular Assist Devices.

    Science.gov (United States)

    Yost, Gardner; Bhat, Geetha; Pappas, Patroklos; Tatooles, Antone

    2018-04-18

    Brain natriuretic peptide (BNP) is a cardiac neurohormone known to correlate with left ventricular (LV) dilation, decreased contractility, and increased stiffness. Consequently, BNP has been used as a prognostic tool to assess the degree of LV unloading for patients supported by continuous-flow LV assist devices (LVADs). We assessed the prognostic value of changes in BNP in the 2 weeks after LVAD implantation. This retrospective study analyzed laboratory findings and outcomes of 189 LVAD patients. Patients were separated into two groups based on whether serum BNP levels had improved from preoperative levels by postoperative day 14. Group 1 had improvement in BNP levels, whereas group 2 had no improvement or worsening in BNP. There were no significant differences between the groups in age, gender, race, body mass index, or comorbidities. Group 1 had preoperative BNP 1,125 ± 1,078.3 pg/dl and postoperative BNP 440.2 ± 267.7 pg/dl (ΔBNP = -693.09 ± 942.4 pg/dl), whereas group 2 had preoperative BNP 346.0 ± 309.1 pg/dl and postoperative BNP 631.57 ± 483.4 pg/dl (ΔBNP = 289.32 ± 329.7 pg/dl). Postoperative survival in group 2 was significantly worse than in group 1. Rates of right ventricular failure (RVF) were significantly higher in group 2 (group 1: 39%, group 2: 52.7%; p = 0.01). In most patients implanted with a LVAD, BNP improves significantly in the postoperative period as the LV is unloaded. Our results indicate that lack of improvement in postoperative BNP is associated with longer length of stay, increased rates of RVF, and is an independent risk factor for reduced postoperative survival.

  19. Is anti-platelet therapy needed in continuous flow left ventricular assist device patients? A single-centre experience.

    Science.gov (United States)

    Litzler, Pierre-Yves; Smail, Hassiba; Barbay, Virginie; Nafeh-Bizet, Catherine; Bouchart, François; Baste, Jean-Marc; Abriou, Caroline; Bessou, Jean-Paul

    2014-01-01

    We report our 5-year experience of continuous flow left ventricular assist device (LVAD) implantation without the use of anti-platelet therapy. Between February 2006 and September 2011, 27 patients (26 men; 1 woman) were implanted with a continuous flow LVAD (HeartMate II, Thoratec Corporation, Pleasanton, CA, USA). The mean age was 55.7 ± 9.9 years. The mean duration of support was 479 ± 436 (1-1555) days with 35.4 patient-years on support. Twenty-one patients were implanted as a bridge to transplantation and 6 for destination therapy. The anticoagulation regimen was fluindione for all patients, with aspirin for only 4 patients. At the beginning of our experience, aspirin was administered to 4 patients for 6, 15, 60 and 460 days. Due to gastrointestinal (GI) bleeding and epistaxis, aspirin was discontinued, and since August 2006, no patients have received anti-platelet therapy. At 3 years, the survival rate during support was 76%. The most common postoperative adverse event was GI bleeding (19%) and epistaxis (30%) (median time: 26 days) for patients receiving fluindione and aspirin. The mean International Normalized Ratio (INR) was 2.58 ± 0.74 during support. Fifteen patients have been tested for acquired Von Willebrand disease. A diminished ratio of collagen-binding capacity and ristocetin cofactor activity to Von Willebrand factor antigen was observed in 7 patients. In the postoperative period, 2 patients presented with ischaemic stroke at 1 and 8 months. One of these 2 patients had a previous history of carotid stenosis with ischaemic stroke. There were no patients with haemorrhagic stroke, transient ischaemic attack or pump thrombosis. The event rate of stroke (ischaemic and haemorrhagic) per patient-year was 0.059 among the patients without aspirin with fluindione regimen only. A fluindione regimen without aspirin in long-duration LVAD support appears to not increase thromboembolic events and could lead to a diminished risk of haemorrhagic stroke.

  20. A practical review for cardiac rehabilitation professionals of continuous-flow left ventricular assist devices: historical and current perspectives.

    Science.gov (United States)

    Compostella, Leonida; Russo, Nicola; Setzu, Tiziana; Bottio, Tomaso; Compostella, Caterina; Tarzia, Vincenzo; Livi, Ugolino; Gerosa, Gino; Iliceto, Sabino; Bellotto, Fabio

    2015-01-01

    An increasing number of patients with end-stage heart failure are being treated with continuous-flow left ventricular assist devices (cf-LVADs). These patients provide new challenges to the staff in exercise-based cardiac rehabilitation (CR) programs. Even though experience remains limited, it seems that patients supported by cf-LVADs may safely engage in typical rehabilitative activities, provided that some attention is paid to specific aspects, such as the presence of a short external drive line. In spite of initial physical deconditioning, CR allows progressive improvement of symptoms such as fatigue and dyspnea. Intensity of rehabilitative activities should ideally be based on measured aerobic capacity and increased appropriately over time. Regular, long-term exercise training results in improved physical fitness and survival rates. Appropriate adjustment of cf-LVAD settings, together with maintenance of adequate blood volume, provides maximal output, while avoiding suction effects. Ventricular arrhythmias, although not necessarily constituting an immediate life-threatening situation, deserve treatment as they could lead to an increased rate of hospitalization and poorer quality of life. Atrial fibrillation may worsen symptoms of right ventricular failure and reduce exercise tolerance. Blood pressure measurements are possible in cf-LVAD patients only using a Doppler technique, and a mean blood pressure ≤80 mmHg is considered "ideal." Some patients may present with orthostatic intolerance, related to autonomic dysfunction. While exercise training constitutes the basic rehabilitative tool, a comprehensive intervention that includes psychological and social support could better meet the complex needs of patients in which cf-LVAD may offer prolonged survival.

  1. Cost-Effectiveness of Ventricular Assist Device Destination Therapy for Advanced Heart Failure in Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Magnetta, Defne A; Kang, JaHyun; Wearden, Peter D; Smith, Kenneth J; Feingold, Brian

    2018-05-17

    Destination ventricular assist device therapy (DT-VAD) is well accepted in select adults with medically refractory heart failure (HF) who are not transplant candidates; however, its use in younger patients with progressive diseases is unclear. We sought to evaluate the cost-effectiveness of DT-VAD in Duchenne muscular dystrophy (DMD) patients with advanced HF. We created a Markov-state transition model (5-year horizon) to compare survival, costs, and quality of life (QOL) between medical management and DT-VAD in DMD with advanced HF. Model input parameters were derived from the literature. We used sensitivity analyses to explore uncertainty around model assumptions. DT-VAD had higher costs ($435,602 vs. $125,696), survival (3.13 vs. 0.60 years), and quality-adjusted survival (1.99 vs. 0.26 years) than medical management. The incremental cost-effectiveness ratio (ICER) for DT-VAD was $179,086 per quality-adjusted life year (QALY). In sensitivity analyses that were widely varied to account for uncertainty in model assumptions, the DT-VAD strategy generally remained more costly and effective than medical management. Only when VAD implantation costs were <$113,142 did the DT-VAD strategy fall below the $100,000/QALY willingness-to-pay threshold commonly considered to be "cost-effective." In this exploratory analysis, DT-VAD for patients with DMD and advanced HF exceeded societal expectations for cost-effectiveness but had an ICER similar to the accepted practice of DT-VAD in adult HF patients. While more experience and research in this population is needed, our analysis suggests that DT-VAD for advanced HF in DMD should not be dismissed solely based on cost.

  2. Association between cell-derived microparticles and adverse events in patients with nonpulsatile left ventricular assist devices.

    Science.gov (United States)

    Nascimbene, Angelo; Hernandez, Ruben; George, Joggy K; Parker, Anita; Bergeron, Angela L; Pradhan, Subhashree; Vijayan, K Vinod; Civitello, Andrew; Simpson, Leo; Nawrot, Maria; Lee, Vei-Vei; Mallidi, Hari R; Delgado, Reynolds M; Dong, Jing Fei; Frazier, O H

    2014-05-01

    Continuous-flow left ventricular assist devices (LVADs) expose blood cells to high shear stress, potentially resulting in the production of microparticles that express phosphatidylserine (PS+) and promote coagulation and inflammation. In this prospective study, we attempted to determine whether PS+ microparticle levels correlate with clinical outcomes in LVAD-supported patients. We enrolled 20 patients undergoing implantation of the HeartMate II LVAD (Thoratec Corp, Pleasanton, CA) and 10 healthy controls who provided reference values for the microparticle assays. Plasma was collected before LVAD implantation, at discharge, at the 3-month follow-up, and when an adverse clinical event occurred. We quantified PS+ microparticles in the plasma using flow cytometry. During the study period, 8 patients developed adverse clinical events: ventricular tachycardia storm in 1, non-ST-elevation myocardial infarction in 2, arterial thrombosis in 2, gastrointestinal bleeding in 2, and stroke in 3. Levels of PS+ microparticles were higher in patients at baseline than in healthy controls (2.11% ± 1.26% vs 0.69% ± 0.46%, p = 0.007). After LVAD implantation, patient PS+ microparticle levels increased to 2.39% ± 1.22% at discharge and then leveled to 1.97% ± 1.25% at the 3-month follow-up. Importantly, levels of PS+ microparticles were significantly higher in patients who developed an adverse event than in patients with no events (3.82% ± 1.17% vs 1.57% ± 0.59%, p microparticle levels may be associated with adverse clinical events. Thus, measuring PS+ microparticle levels in LVAD-supported patients may help identify patients at increased risk for adverse events. Copyright © 2014 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  3. Device-Training for Individuals with Thoracic and Lumbar Spinal Cord Injury Using a Powered Exoskeleton for Technically Assisted Mobility: Achievements and User Satisfaction

    Science.gov (United States)

    Gillner, Annett; Borgwaldt, Nicole; Kroll, Sylvia; Roschka, Sybille

    2016-01-01

    Objective. Results of a device-training for nonambulatory individuals with thoracic and lumbar spinal cord injury (SCI) using a powered exoskeleton for technically assisted mobility with regard to the achieved level of control of the system after training, user satisfaction, and effects on quality of life (QoL). Methods. Observational single centre study with a 4-week to 5-week intensive inpatient device-training using a powered exoskeleton (ReWalk™). Results. All 7 individuals with SCI who commenced the device-training completed the course of training and achieved basic competences to use the system, that is, the ability to stand up, sit down, keep balance while standing, and walk indoors, at least with a close contact guard. User satisfaction with the system and device-training was documented for several aspects. The quality of life evaluation (SF-12v2™) indicated that the use of the powered exoskeleton can have positive effects on the perception of individuals with SCI regarding what they can achieve physically. Few adverse events were observed: minor skin lesions and irritations were observed; no falls occurred. Conclusions. The device-training for individuals with thoracic and lumbar SCI was effective and safe. All trained individuals achieved technically assisted mobility with the exoskeleton while still needing a close contact guard. PMID:27610382

  4. Device-Training for Individuals with Thoracic and Lumbar Spinal Cord Injury Using a Powered Exoskeleton for Technically Assisted Mobility: Achievements and User Satisfaction

    Directory of Open Access Journals (Sweden)

    Thomas Platz

    2016-01-01

    Full Text Available Objective. Results of a device-training for nonambulatory individuals with thoracic and lumbar spinal cord injury (SCI using a powered exoskeleton for technically assisted mobility with regard to the achieved level of control of the system after training, user satisfaction, and effects on quality of life (QoL. Methods. Observational single centre study with a 4-week to 5-week intensive inpatient device-training using a powered exoskeleton (ReWalk™. Results. All 7 individuals with SCI who commenced the device-training completed the course of training and achieved basic competences to use the system, that is, the ability to stand up, sit down, keep balance while standing, and walk indoors, at least with a close contact guard. User satisfaction with the system and device-training was documented for several aspects. The quality of life evaluation (SF-12v2™ indicated that the use of the powered exoskeleton can have positive effects on the perception of individuals with SCI regarding what they can achieve physically. Few adverse events were observed: minor skin lesions and irritations were observed; no falls occurred. Conclusions. The device-training for individuals with thoracic and lumbar SCI was effective and safe. All trained individuals achieved technically assisted mobility with the exoskeleton while still needing a close contact guard.

  5. Abnormal biventricular performance in asymptomatic adolescents late after repaired Tetralogy of Fallot: Combined two-dimensional speckle tracking and three-dimensional echocardiography study

    Directory of Open Access Journals (Sweden)

    Ken-Pen Weng

    2018-02-01

    Conclusion: Our results suggest asymptomatic adolescents with repaired TOF had abnormal biventricular myocardial performance, as demonstrated by combined 2D speckle-tracking and 3D echocardiography. The implications of these findings for management of adolescents late after repaired TOF remain to be determined.

  6. Y stenting assisted coiling using a new low profile visible intraluminal support device for wide necked basilar tip aneurysms: a technical report.

    Science.gov (United States)

    Conrad, Marcelo D; Brasiliense, Leonardo B C; Richie, Alexa N; Hanel, Ricardo A

    2014-05-01

    Many endovascular techniques have been described in recent years for the management of wide necked aneurysms. The Y stent assisted technique has been generally used for coil embolization of wide necked bifurcation aneurysms. This technique was first described for the treatment of basilar tip aneurysms in combination with several different devices, demonstrating encouraging results. We report the results of the first two cases of wide necked basilar tip aneurysms treated with Y stent assisted coil embolization using a new low profile visible intraluminal stent (LVIS Jr; MicroVention, Tustin, California, USA) delivered through a 0.017 inch microcatheter. We also reviewed the literature comparing other endovascular techniques (coiling alone, stent assisted coiling, and Y stent assisted coiling) for wide necked aneurysms. The LVIS Jr device offers a new option for the treatment of these challenging lesions, with clear advantages over currently available intracranial stents. Larger series and long term results are needed to confirm the applicability and durability of this technique/technology.

  7. Management of single-ventricle patients with Berlin Heart EXCOR Ventricular Assist Device: single-center experience.

    Science.gov (United States)

    Mackling, Tracey; Shah, Tejas; Dimas, Vivian; Guleserian, Kristine; Sharma, Mahesh; Forbess, Joseph; Ardura, Monica; Gross-Toalson, Jami; Lee, Ying; Journeycake, Janna; Barnes, Aliessa

    2012-06-01

    There are minimal data regarding chronic management of single-ventricle ventricular assist device (VAD) patients. This study aims to describe our center's multidisciplinary team management of single-ventricle patients supported long term with the Berlin Heart EXCOR Pediatric VAD. Patient #1 was a 4-year-old with double-outlet right ventricle with aortic atresia, L-looped ventricles, and heart block who developed heart failure 1 year after Fontan. She initially required extracorporeal membrane oxygenation support and was transitioned to Berlin Heart systemic VAD. She was supported for 363 days (cardiac intensive care unit [CICU] 335 days, floor 28 days). The postoperative course was complicated by intermittent infection including methicillin-resistant Staphylococcus aureus, intermittent hepatic and renal insufficiencies, and transient antithrombin, protein C, and protein S deficiencies resulting in multiple thrombi. She had a total of five pump changes over 10 months. Long-term medical management included anticoagulation with enoxaparin, platelet inhibition with aspirin and dipyridamole, and antibiotic prophylaxis using trimethoprim/sulfamethoxazole. She developed sepsis of unknown etiology and subsequently died from multiorgan failure. Patient #2 was a 4-year-old with hypoplastic left heart syndrome who developed heart failure 2 years after bidirectional Glenn shunt. At systemic VAD implantation, he was intubated with renal insufficiency. Post-VAD implantation, his renal insufficiency resolved, and he was successfully extubated to daytime nasal cannula and biphasic positive airway pressure at night. He was supported for 270 days (CICU 143 days, floor 127 days). The pump was upsized to a 50-mL pump in May 2011 for increased central venous pressures (29 mm Hg). Long-term medical management included anticoagulation with warfarin and single-agent platelet inhibition using dipyridamole due to aspirin resistance. He developed increased work of breathing requiring

  8. Two new dynamic devices / orthoses for training / assisting / rehabilitation of hand functionality in patients with stroke as a result of clinical experience

    Directory of Open Access Journals (Sweden)

    Catalin Moghioroiu

    2016-12-01

    Full Text Available Introduction - Observing stroke patients with hemiplegia we can easily identify one of the problems they face –inability to use affected upper limb. On a closer analysis we can see that this incapacity is determined, at many of them, by the incapacity to open the hand and grasp. They follow therapies for months and the results are often mediocre therefore respectively upper limb is neglected and forgotten and its activities are taken up by the healthy upper limb. These observations have prompted the search for other type of solutions to help / assist them and facilitate participation. In this way were created twodynamic devices/orthotics that assists finger extension, facilitates grasping and increase, at least in theory, the possibilities of participation. Objective - The main purpose of this study is to test the effectiveness of using these devices on short and medium term. Material and method - For this study we will select 60 patients with single stroke. Patients will be randomized into two groups. Patients in the control group will receive a physical therapy session per day for 10 days. Patients in the experimental group will receive in addition a functional workout (20-30 minutes of handling small objects and few simple functional gestures of the "activities of daily living" using one of the two devices –the one that will allow the patient to best accomplish the given tasks. We will perform an initial assessment, one final and one to three months. The initiation of this study will be made after obtaining the opinion of the ethics committee, and the inclusion of patients will occur only after obtaining informed consent. Conclusions - Creation of two dynamic devices/orthotics witch assist finger extension and facilitate prehension opened the possibility of carrying out a clinical trial to test the effectiveness of their use. To what extent that this will happen remains to be seen.

  9. Rehabilitation Engineering & Assistive Technology Society (RESNA) position on the application of wheelchair standing devices: 2013 current state of the literature.

    Science.gov (United States)

    Dicianno, Brad E; Morgan, Amy; Lieberman, Jenny; Rosen, Lauren

    2016-01-01

    This article, approved by the Rehabilitation Engineering & Assistive Technology Society of North America Board of Directors on December 23, 2013, shares typical clinical applications and provides evidence from the literature supporting the use of wheelchair standers.

  10. Laser-Assisted Simultaneous Transfer and Patterning of Vertically Aligned Carbon Nanotube Arrays on Polymer Substrates for Flexible Devices

    KAUST Repository

    In, Jung Bin; Lee, Daeho; Fornasiero, Francesco; Noy, Aleksandr; Grigoropoulos, Costas P.

    2012-01-01

    We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet

  11. When withdrawal of life-sustaining care does more than allow death to take its course: the dilemma of left ventricular assist devices.

    Science.gov (United States)

    Bramstedt, K A; Wenger, N S

    2001-05-01

    Left ventricular assist devices (LVADs) are a relatively new technology that is increasingly used to preserve cardiac function. These devices work by a mechanism that may complicate ethical decision-making for patients who subsequently lose decision-making capacity and are no longer considered transplant candidates. Using a clinical case from our medical center, we explored the complex ethical issues associated with the discontinuation of LVAD therapy by discussing how this device is distinct from the withdrawal of other treatments. While halting an implanted LVAD may permit a patient to die, the deactivated device itself may contribute to patient death due to the potential for blood backflow and pooling, as well as the disruption of heart contractility. Inadequate informed consent and failure to appoint a surrogate decision-maker in advance of the implant procedure resulted in a complex ethical dilemma for the patient's family and the medical team. Clinicians and families must consider the benefits and burdens of LVAD therapy as they do when considering removal of other life-sustaining treatment. The informed consent process associated with LVADs as bridging technology should include extensive consideration of the purpose of the device, future circumstances in which it may be halted, and how such situations would be recognized and handled. Appointment of a surrogate decision-maker before the surgical procedure is essential.

  12. Portable vibration-assisted filtration device for on-site isolation of blood cells or pathogenic bacteria from whole human blood.

    Science.gov (United States)

    Kim, Yong Tae; Park, Kyun Joo; Kim, Seyl; Kim, Soon Ae; Lee, Seok Jae; Kim, Do Hyun; Lee, Tae Jae; Lee, Kyoung G

    2018-03-01

    Isolation of specific cells from whole blood is important to monitor disease prognosis and diagnosis. In this study, a vibration-assisted filtration (VF) device has been developed for isolation and recovery of specific cells such as leukocytes and pathogenic bacteria from human whole blood. The VF device is composed of three layers which was fabricated using injection molding with cyclic olefin copolymer (COC) pellets consisting of: a top layer with coin-type vibration motor (Ф = 10mm), a middle plate with a 1μm or 3μm-pore filter membrane to separate of Staphylococcus aureus (S. aureus) cells or leukocytes (i.e. white blood cells) respectively, and a bottom chamber with conical-shaped microstructure. One milliliter of human whole blood was injected into a sample loading chamber using a 3μm-pore filter equipped in the VF device and the coin-type vibration motor applied external vibration force by generating a rotational fluid which enhances the filtration velocity due to the prevention of the cell clogging on the filter membrane. The effluent blood such as erythrocytes, platelet, and plasma was collected at the bottom chamber while the leukocytes were sieved by the filter membrane. The vibration-assisted leukocyte separation was able to finish within 200s while leukocyte separation took 1200s without vibration. Moreover, we successfully separated S. aureus from human whole blood using a 1μm-pore filter equipped VF device and it was further confirmed by genetic analysis. The proposed VF device provides an advanced cell separation platform in terms of simplicity, fast separation, and portability in the fields of point-of-care diagnostics. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Validity and reliability of a novel slow cuff-deflation system for noninvasive blood pressure monitoring in patients with continuous-flow left ventricular assist device.

    Science.gov (United States)

    Lanier, Gregg M; Orlanes, Khristine; Hayashi, Yacki; Murphy, Jennifer; Flannery, Margaret; Te-Frey, Rosie; Uriel, Nir; Yuzefpolskaya, Melana; Mancini, Donna M; Naka, Yoshifumi; Takayama, Hiroo; Jorde, Ulrich P; Demmer, Ryan T; Colombo, Paolo C

    2013-09-01

    Doppler ultrasound is the clinical gold standard for noninvasive blood pressure (BP) measurement among continuous-flow left ventricular assist device patients. The relationship of Doppler BP to systolic BP (SBP) and mean arterial pressure (MAP) is uncertain and Doppler measurements require a clinic visit. We studied the relationship between Doppler BP and both arterial-line (A-line) SBP and MAP. Validity and reliability of the Terumo Elemano BP Monitor, a novel slow cuff-deflation device that could potentially be used by patients at home, were assessed. Doppler and Terumo BP measurements were made in triplicate among 60 axial continuous-flow left ventricular assist device (HeartMate II) patients (30 inpatients and 30 outpatients) at 2 separate exams (360 possible measurements). A-line measures were also obtained among inpatients. Mean absolute differences (MADs) and correlations were used to determine within-device reliability (comparison of second and third BP measures) and between-device validity. Bland-Altman plots assessed BP agreement between A-line, Doppler BP, and Terumo Elemano. Success rates for Doppler and Terumo Elemano were 100% and 91%. Terumo Elemano MAD for repeat SBP and MAP were 4.6±0.6 and 4.2±0.6 mm Hg; repeat Doppler BP MAD was 2.9±0.2 mm Hg. Mean Doppler BP was lower than A-line SBP by 4.1 (MAD=6.4±1.4) mm Hg and higher than MAP by 9.5 (MAD=11.0±1.2) mm Hg; Terumo Elemano underestimated A-line SBP by 0.3 (MAD=5.6±0.9) mm Hg and MAP by 1.7 (MAD=6.0±1.0) mm Hg. Doppler BP more closely approximates SBP than MAP. Terumo Elemano was successful, reliable, and valid when compared with A-line and Doppler.

  14. The attitudes of Australian radiography students towards the use of assistive transfer devices to reduce biomechanical stress in the clinical setting

    International Nuclear Information System (INIS)

    Ngo, Mark; Schneider-Kolsky, Michal; Baird, Marilyn

    2013-01-01

    The duties performed by radiographers, which includes transferring patients onto and off the examination table, can increase their risk of developing back and neck pain. This study used a survey to identify the assistive transfer devices Australian radiography undergraduate students are familiar with and have had practise using in the clinical setting. It also sought to determine whether students are being encouraged by other radiographers to use these devices during clinical training and if they would conform to practicing unsafe transfers if instructed to by senior staff. Results indicated that radiography students were familiar with the majority of the surveyed assistive devices such as the Patslide and X-ray cassette slider. Many of the students were unlikely to participate in unsafe work practices and were able to provide alternative methods of transferring patients. However, some of the respondents could be coerced into participating in unsafe patient transfers. Radiographers should therefore be vigilant in refraining from practicing unsafe transfer techniques as it could lead to students believing it is acceptable and emulating these practices in the work place

  15. Arthroscopically Assisted Coracoclavicular Fixation Using a Single Flip Button Device Technique: What Are the Main Factors Affecting the Maintenance of Reduction?

    Directory of Open Access Journals (Sweden)

    Yong-Beom Lee

    2017-01-01

    Full Text Available Background. Among coracoclavicular (CC fixation techniques, the use of flip button device was demonstrated to have successful outcomes with the advantage of being able to accommodate an arthroscopic procedure. Purpose. This study was conducted to investigate the factors associated with loss of fixation after arthroscopically assisted CC fixation using a single flip button device for acromioclavicular (AC joint dislocations. Materials and Methods. We enrolled a total of 47 patients (35 men and 12 women. Plain radiography was performed at a mean of 24 months postoperatively to evaluate the final radiological outcome. The primary outcome measure was a long-term reduction of the AC joint for at least 24 months. Results. We found that 29 patients had a high quality reduction (61.7% and 18 patients had a low quality reduction (38.3% in initial postoperative CT findings. Our study showed that the duration (5 days from injury to treatment and the quality of initial postoperative reduction were significantly associated with the maintenance of reduction at final follow-up. Conclusion. Our study showed that maintaining stable reduction after arthroscopically assisted CC fixation using a single flip button device technique is difficult especially in patients who received delayed treatment or whose initial reduction quality was poor.

  16. Animal magnetocardiography using superconducting quantum interference device gradiometers assisted with magnetic nanoparticle injection: A sensitive method for early detecting electromagnetic changes induced by hypercholesterolemia

    Science.gov (United States)

    Wu, C. C.; Hong, B. F.; Wu, B. H.; Yang, S. Y.; Horng, H. E.; Yang, H. C.; Tseng, W. Y. Isaac; Tseng, W. K.; Liu, Y. B.; Lin, L. C.; Lu, L. S.; Lee, Y. H.

    2007-01-01

    In this work, the authors used a superconducting quantum interference device (SQUID) magnetocardiography (MCG) system consisted of 64-channel low-transition-temperature SQUID gradiometers to detect the MCG signals of hepercholesterolemic rabbits. In addition, the MCG signals were recorded before and after the injection of magnetic nanoparticles into the rabbits' ear veins to investigate the effects of magnetic nanoparticles on the MCG signals. These MCG data were compared to those of normal rabbits to reveal the feasibility for early detection of the electromagnetic changes induced by hypercholesterolemia using MCG with the assistance of magnetic nanoparticle injection.

  17. The Effect of Preoperative Cognitive Behavior and Exercise Therapy for a Patient With an Implanted Left Ventricular Assist Device in Korea.

    Science.gov (United States)

    Seo, Yong Gon; Park, Won Hah; Jeon, Eun Seok; Sung, Ji Dong; Jang, Mi Ja

    2017-10-01

    Left ventricular assist devices (LVADs) are used in patients with progressive heart failure symptoms to provide circulatory support. Patients with LVADs are referred to inpatient cardiac rehabilitation to prevent postoperative complications and improve aerobic capacity and quality of life. Preoperative exercise therapy for cardiac patients is an emerging treatment modality, and several studies have reported that it improves postoperative outcomes, such as length of hospital stay and postoperative complications. This case report describes the benefits of preoperative cognitive behavioral and exercise therapy in a Korean patient undergoing LVAD implantation. V. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  18. Relation Between Pressure and Volume Unloading During Ramp Testing in Patients Supported with a Continuous-Flow Left Ventricular Assist Device

    DEFF Research Database (Denmark)

    Jung, Mette H; Hassager, Christian; Balling, Louise

    2015-01-01

    Pulmonary capillary wedge pressure (PCWP) is the key to describing left ventricular (LV) unloading, however, the relation between pressure and the echocardiography-derived surrogate of LV volume (left ventricular end-diastolic diameter (LVEDD)) as a function of pump speed (RPM) in continuous......-flow left ventricular assist device (CF-LVAD) patients is unknown. In this study the pressure-volume relationship as a function of RPM during ramp testing was investigated by simultaneously measuring PCWP by Swan-Ganz catheter and LVEDD by echocardiography. The ramp protocol started at usual pump setting...

  19. Arthroscopically assisted reduction of acute acromioclavicular joint dislocation using a single double-button device: Medium-term clinical and radiological outcomes.

    Science.gov (United States)

    Issa, S-P; Payan, C; Le Hanneur, M; Loriaut, P; Boyer, P

    2018-02-01

    Double-button devices for endoscopic management of acute acromioclavicular joint dislocation (ACJD) provide satisfactory short-term functional and radiological results. However, little exists in the literature regarding the long- and medium-term results of these implants, especially regarding the evolution of the acromioclavicular joint (ACJ). Satisfactory and steady long- and medium-term outcomes can be achieved in patients with acute ACJD undergoing endoscopically assisted ACJ repair using a single double-button device. A retrospective single-center study was conducted in patients with acute Rockwood III and IV ACJD treated endoscopically with a single double-button device from October 2008 to October 2010, allowing a minimum 5-year follow-up. Functional evaluation used Constant and Quick-DASH scores. Clinical evidence of dislocation recurrence was combined with bilateral Zanca views to assess coracoclavicular distance. Acromioclavicular osteoarthritis was evaluated on the Paxinos test and Zanca views. Nineteen of the 25 operated patients were seen at a mean 76.9±8.5 months' follow-up. Mean age was 34.4±8.3 years. Mean Constant and Quick-DASH scores were 96.2±5.1 and 0.9±1.6 points, respectively. Four patients had a recurrence of their initial dislocation, 3 of whom had positive Paxinos test, whereas the 15 patients without recurrence had a negative test (p=0.004). Five patients had radiological evidence of ACJ osteoarthritis: all 4 patients with recurrence and 1 without (p=0.001). Long- and medium-term radioclinical outcome of endoscopically assisted management of acute ACJD using a single double-button device seems to be satisfactory and steady over time. Recurrence of the initial dislocation appears to be related to onset of degenerative ACJ arthropathy. Therapeutic type IV-Retrospective case series. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Theoretical and experimental analysis of a solar thermoelectric power generation device based on gravity-assisted heat pipes and solar irradiation

    International Nuclear Information System (INIS)

    Zhang, Zhe; Li, Wenbin; Kan, Jiangming; Xu, Daochun

    2016-01-01

    Highlights: • A technical solution to the power supply of wireless sensor networks is presented. • The low voltage produced by device is boosted from around 1 V to more than 4 V. • An output current and voltage of the device is acquired as 343 mA and 1057 mV. • The device provides output power 362.56 mW in no electricity conditions. • The economic value of device is demonstrated. - Abstract: Solar thermoelectric power generation has been widely used to solve the power supply limitation issue for low-power wireless sensors because of its light weight, high reliability, low cost, lack of noise, and environmental friendliness. A solar thermoelectric power generation system based on gravity-assisted heat pipes and solar radiation is devised in this paper, and its behavior is continuously measured in realistic outdoor circumstances. The effects of key parameters, including solar luminous flux, load resistance, a proportional coefficient, and a relative Seebeck coefficient, are analyzed. Related experimental results show that the device can output a voltage of 1057 mV and an electrical current of 343 mA, resulting in an output power of 362.56 mW. With a stable external energy conversion module under aluminous flux of 7.81 × 10"4 lx, the voltage converted from the nature solar radiation is boosted from 1057 mV to 4.40 V, which meets the rated operating voltage of low power consumption components, such as low-power wireless sensors and ZigBee modules. An economic analysis of the system shows that the solar thermoelectric power generation device is both economically and technically competitive when it is applied in a low-voltage wireless sensor network.

  1. Knowledge from Research and Practice on the Barriers and Carriers to Successful Technology Transfer for Assistive Technology Devices

    Science.gov (United States)

    Leahy, James A.; Lane, Joseph P.

    2010-01-01

    Historically, the assistive technology (AT) industry is made up of small to medium size companies serving relatively small markets with products characterized as "niche" or "orphan" products. Presenting opportunities to AT companies that are created by outside sources is difficult. Presenting such opportunities to companies serving larger markets…

  2. Multi-scale theory-assisted nano-engineering of plasmonic-organic hybrid electro-optic device performance

    Science.gov (United States)

    Elder, Delwin L.; Johnson, Lewis E.; Tillack, Andreas F.; Robinson, Bruce H.; Haffner, Christian; Heni, Wolfgang; Hoessbacher, Claudia; Fedoryshyn, Yuriy; Salamin, Yannick; Baeuerle, Benedikt; Josten, Arne; Ayata, Masafumi; Koch, Ueli; Leuthold, Juerg; Dalton, Larry R.

    2018-02-01

    Multi-scale (correlated quantum and statistical mechanics) modeling methods have been advanced and employed to guide the improvement of organic electro-optic (OEO) materials, including by analyzing electric field poling induced electro-optic activity in nanoscopic plasmonic-organic hybrid (POH) waveguide devices. The analysis of in-device electro-optic activity emphasizes the importance of considering both the details of intermolecular interactions within organic electro-optic materials and interactions at interfaces between OEO materials and device architectures. Dramatic improvement in electro-optic device performance-including voltage-length performance, bandwidth, energy efficiency, and lower optical losses have been realized. These improvements are critical to applications in telecommunications, computing, sensor technology, and metrology. Multi-scale modeling methods illustrate the complexity of improving the electro-optic activity of organic materials, including the necessity of considering the trade-off between improving poling-induced acentric order through chromophore modification and the reduction of chromophore number density associated with such modification. Computational simulations also emphasize the importance of developing chromophore modifications that serve multiple purposes including matrix hardening for enhanced thermal and photochemical stability, control of matrix dimensionality, influence on material viscoelasticity, improvement of chromophore molecular hyperpolarizability, control of material dielectric permittivity and index of refraction properties, and control of material conductance. Consideration of new device architectures is critical to the implementation of chipscale integration of electronics and photonics and achieving the high bandwidths for applications such as next generation (e.g., 5G) telecommunications.

  3. Beneficial aspects of real time flow measurements for the management of acute right ventricular heart failure following continuous flow ventricular assist device implantation

    Directory of Open Access Journals (Sweden)

    Spiliopoulos Sotirios

    2012-11-01

    Full Text Available Abstract Background Optimal management of acute right heart failure following the implantation of a left ventricular assist device requires a reliable estimation of left ventricular preload and contractility. This is possible by real-time pump blood flow measurements. Clinical case We performed implantation of a continuous flow left ventricular assist device in a 66 years old female patient with an end-stage heart failure on the grounds of a dilated cardiomyopathy. Real-time pump blood flow was directly measured by an ultrasonic flow probe placed around the outflow graft. Diagnosis The progressive decline of real time flow and the loss of pulsatility were associated with an increase of central venous pressure, inotropic therapy and progressive renal failure suggesting the presence of an acute right heart failure. Diagnosis was validated by echocardiography and thermodilution measurements. Treatment Temporary mechanical circulatory support of the right ventricle was successfully performed. Real time flow measurement proved to be a useful tool for the diagnosis and ultimately for the management of right heart failure including the weaning from extracorporeal membrane oxygenation.

  4. The extent of using mobility assistive devices can partly explain fatigue among persons with late effects of polio - a retrospective registry study in Sweden.

    Science.gov (United States)

    Santos Tavares Silva, I; Sunnerhagen, K S; Willén, C; Ottenvall Hammar, I

    2016-11-18

    Fatigue is reported as one of the most disabling symptoms and is common among persons living with late effects of polio. Although fatigue has been studied in the context of people living with late effects of polio, there is a lack of knowledge concerning the association of fatigue and variables of importance for participation in daily life. Therefore, the aim of this study was to explore possible factors associated with fatigue among persons with late effects of polio in Sweden. This retrospective registry study consisted of 89 persons with late effects of polio living in Sweden. Fatigue was measured with the Multidimensional Fatigue Inventory (MFI-20) scale, Swedish version. Pearson's correlation coefficient was used to analyse the correlation between the factors and fatigue, and a multiple linear regression was carried out to explore factors for fatigue. Fatigue statistically significantly correlated with age (r = 0.234, p polio, and the model partly explained 14% of the variation of fatigue. Fatigue could partly be explained by the extent of using mobility assistive devices and age. Healthcare professionals should provide and demonstrate the importance of assistive devices to ensure management of fatigue in persons living with late effects of polio.

  5. The role of cerebral hyperperfusion in postoperative neurologic dysfunction after left ventricular assist device implantation for end-stage heart failure.

    Science.gov (United States)

    Lietz, Katherine; Brown, Kevin; Ali, Syed S; Colvin-Adams, Monica; Boyle, Andrew J; Anderson, David; Weinberg, Alan D; Miller, Leslie W; Park, Soon; John, Ranjit; Lazar, Ronald M

    2009-04-01

    Cerebral hyperperfusion is a life-threatening syndrome that can occur in patients with chronically hypoperfused cerebral vasculature whose normal cerebral circulation was re-established after carotid endarterectomy or angioplasty. We sought to determine whether the abrupt restoration of perfusion to the brain after left ventricular assist device (LVAD) implantation produced similar syndromes. We studied the role of increased systemic flow after LVAD implantation on neurologic dysfunction in 69 consecutive HeartMate XVE LVAD (Thoratec, Pleasanton, Calif) recipients from October 2001 through June 2006. Neurologic dysfunction was defined as postoperative permanent or transient central change in neurologic status, including confusion, focal neurologic deficits, visual changes, seizures, or coma for more than 24 hours within 30 days after LVAD implantation. We found that 19 (27.5%) patients had neurologic dysfunction, including encephalopathy (n = 11), coma (n = 3), and other complications (n = 5). The multivariate analysis showed that an increase in cardiac index from the preoperative baseline value (relative risk, 1.33 per 25% cardiac index increase; P = .01) and a previous coronary bypass operation (relative risk, 4.53; P = .02) were the only independent predictors of neurologic dysfunction. Reduction of left ventricular assist device flow in 16 of the 19 symptomatic patients led to improvement of symptoms in 14 (87%) patients. Our findings showed that normal flow might overwhelm cerebral autoregulation in patients with severe heart failure, suggesting that cerebral hyperperfusion is possible in recipients of mechanical circulatory support with neurologic dysfunction.

  6. Myocardial changes in patients with end-stage heart failure during continuous flow left ventricular assist device support

    NARCIS (Netherlands)

    Lok, S.I.

    2013-01-01

    With respect to the clinical outcome, cf-LVADs provide sufficient ventricular unloading and circulatory support. The post-operative mortality and morbidity in our centre are comparable with other recent experiences with this device. Based on these data, Heart Mate II (HM II) LVAD therapy can be

  7. Providers with Limited Experience Perform Better in Advanced Life Support with Assistance Using an Interactive Device with an Automated External Defibrillator Linked to a Ventilator.

    Science.gov (United States)

    Busch, Christian Werner; Qalanawi, Mohammed; Kersten, Jan Felix; Kalwa, Tobias Johannes; Scotti, Norman Alexander; Reip, Wikhart; Doehn, Christoph; Maisch, Stefan; Nitzschke, Rainer

    2015-10-01

    Medical teams with limited experience in performing advanced life support (ALS) or with a low frequency of cardiopulmonary resuscitation (CPR) while on duty, often have difficulty complying with CPR guidelines. This study evaluated whether the quality of CPR of trained medical students, who served as an example of teams with limited experience in ALS, could be improved with device assistance. The primary outcome was the hands-off time (i.e., the percentage of the entire CPR time without chest compressions). The secondary outcome was seven time intervals, which should be as short as possible, and the quality of ventilations and chest compressions on the mannequin. We compared standard CPR equipment to an interactive device with visual and acoustic instructions for ALS workflow measures to guide briefly trained medical students through the ALS algorithm in a full-scale mannequin simulation study with a randomized crossover study design. The study equipment consisted of an automatic external defibrillator and ventilator that were electronically linked and communicating as a single system. Included were regular medical students in the third to sixth years of medical school of one class who provided written informed consent for voluntary participation and for the analysis of their CPR performance data. No exclusion criteria were applied. For statistical measures of evaluation we used an analysis of variance for crossover trials accounting for treatment effect, sequence effect, and carry-over effect, with adjustment for prior practical experience of the participants. Forty-two medical students participated in 21 CPR sessions, each using the standard and study equipment. Regarding the primary end point, the study equipment reduced the hands-off time from 40.1% (95% confidence interval [CI] 36.9-43.4%) to 35.6% (95% CI 32.4-38.9%, p = 0.031) compared with the standard equipment. Within the prespecified secondary end points, study equipment reduced the time interval until

  8. Identification and Management of Pump Thrombus in the HeartWare Left Ventricular Assist Device System: A Novel Approach Using Log File Analysis.

    Science.gov (United States)

    Jorde, Ulrich P; Aaronson, Keith D; Najjar, Samer S; Pagani, Francis D; Hayward, Christopher; Zimpfer, Daniel; Schlöglhofer, Thomas; Pham, Duc T; Goldstein, Daniel J; Leadley, Katrin; Chow, Ming-Jay; Brown, Michael C; Uriel, Nir

    2015-11-01

    The study sought to characterize patterns in the HeartWare (HeartWare Inc., Framingham, Massachusetts) ventricular assist device (HVAD) log files associated with successful medical treatment of device thrombosis. Device thrombosis is a serious adverse event for mechanical circulatory support devices and is often preceded by increased power consumption. Log files of the pump power are easily accessible on the bedside monitor of HVAD patients and may allow early diagnosis of device thrombosis. Furthermore, analysis of the log files may be able to predict the success rate of thrombolysis or the need for pump exchange. The log files of 15 ADVANCE trial patients (algorithm derivation cohort) with 16 pump thrombus events treated with tissue plasminogen activator (tPA) were assessed for changes in the absolute and rate of increase in power consumption. Successful thrombolysis was defined as a clinical resolution of pump thrombus including normalization of power consumption and improvement in biochemical markers of hemolysis. Significant differences in log file patterns between successful and unsuccessful thrombolysis treatments were verified in 43 patients with 53 pump thrombus events implanted outside of clinical trials (validation cohort). The overall success rate of tPA therapy was 57%. Successful treatments had significantly lower measures of percent of expected power (130.9% vs. 196.1%, p = 0.016) and rate of increase in power (0.61 vs. 2.87, p file parameters can potentially predict the likelihood of successful tPA treatments and if validated prospectively, could substantially alter the approach to thrombus management. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  9. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    International Nuclear Information System (INIS)

    Wang Ziming; Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi; Ma Qiang; Lu Chunmei; Dong Deming

    2013-01-01

    Highlights: ► An absorbing microwave μ-SPE device packed with activated carbon was used. ► Absorbing microwave μ-SPE device was made and used to enrich the analytes. ► Absorbing microwave μ-SPE device was made and used to heat samples directly. ► MAE-μ-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC–MS without any clean-up process. The recoveries were in the range of 93.5–104.6%, and the relative standard deviations were lower than 8.7%.

  10. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ziming, E-mail: wangziming@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ma Qiang [Chinese Academy of Inspection and Quarantine, Beijing 100123 (China); Lu Chunmei [College of Technology Center, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Dong Deming [College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer An absorbing microwave {mu}-SPE device packed with activated carbon was used. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to enrich the analytes. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to heat samples directly. Black-Right-Pointing-Pointer MAE-{mu}-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction ({mu}-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave {mu}-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in {mu}-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave {mu}-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 Degree-Sign C for 10 min. The extracts obtained by MAE-{mu}-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%.

  11. Outcomes of pediatric patients supported with continuous-flow ventricular assist devices: A report from the Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS).

    Science.gov (United States)

    Rossano, Joseph W; Lorts, Angela; VanderPluym, Christina J; Jeewa, Aamir; Guleserian, Kristine J; Bleiweis, Mark S; Reinhartz, Olaf; Blume, Elizabeth D; Rosenthal, David N; Naftel, David C; Cantor, Ryan S; Kirklin, James K

    2016-05-01

    Continuous-flow (CF) ventricular assist devices (VADs) have largely replaced pulsatile-flow VADs in adult patients. However, there are few data on CF VADs among pediatric patients. In this study we aimed to describe the overall use, patients' characteristics and outcomes of CF VADs in this population. The Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS) is a national registry for U.S. Food and Drug Adminstration (FDA)-approved VADs in patients <19 years of age. Patients undergoing placement of durable CF VADs between September 2012 and June 2015 were included and outcomes were compared with those of adults from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). CF VADs were implanted in 109 patients at 35 hospitals. The median age at implantation was 15 years (2.8 to 18.9 years) and median weight was 62 kg (range 16 to 141 kg). The underlying disease was cardiomyopathy in 89 (82%) patients. The INTERMACS level at time of implant was Level 1 in 20 (19%), Level 2 in 64 (61%) and Levels 3 to 7 in 21 (20%) patients. Most were implanted as LVADs (n = 102, 94%). Median duration of support was 2.3 months (range <1 day to 28 months). Serious adverse event rates were low, including neurologic dysfunction (early event rate 4.1 per 100 patient-months with 2 late events). Competing outcomes analysis at 6 months post-implant indicated 61% transplanted, 31% alive with device in place and 8% death before transplant. These outcomes compared favorably with the 3,894 adults supported with CF VADs as a bridge to transplant. CF VADs are commonly utilized in older children and adolescents, with excellent survival rates. Further study is needed to understand impact of patient and device characteristics on outcomes in pediatric patients. Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  12. Changes after surgically-assisted maxillary expansion (SARME) to the dentoalveolar, palatal and nasal structures by using tooth-borne distraction devices.

    Science.gov (United States)

    Seeberger, Robin; Kater, Wolfgang; Schulte-Geers, Michael; Davids, Rolf; Freier, Kolja; Thiele, Oliver

    2011-07-01

    Different devices are available to aid surgically-assisted maxillary expansion. In this study we have evaluated the changes to the anchoring teeth, the hard palate, and the lower nasal passage made by tooth-borne distraction devices. Thirty-one patients (mean (SD) age 28 (2) years) with deficiencies in the transverse width of the maxilla were examined by computed tomography and cone beam scans before and after operation. The data were analysed with the help of Wilcoxon's signed rank test and Spearman's r correlation. The mean (SD) distraction width was 6.5 (2.3) mm. All anchorage teeth were tilted (pdistraction width, with changes in the intercoronal and interapical distances of the anchoring premolars (pdistraction width and the overall gain in width of the lower nasal passage (pmaxillary expansion with tooth-borne devices has significant effects on the anchoring teeth, the nasal floor, and the hard palate. Both tilting of the teeth and an evenly distributed movement of the segments were seen. Copyright © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  13. Partial spin absorption induced magnetization switching and its voltage-assisted improvement in an asymmetrical all spin logic device at the mesoscopic scale

    Science.gov (United States)

    Zhang, Yue; Zhang, Zhizhong; Wang, Lezhi; Nan, Jiang; Zheng, Zhenyi; Li, Xiang; Wong, Kin; Wang, Yu; Klein, Jacques-Olivier; Khalili Amiri, Pedram; Zhang, Youguang; Wang, Kang L.; Zhao, Weisheng

    2017-07-01

    Beyond memory and storage, future logic applications put forward higher requirements for electronic devices. All spin logic devices (ASLDs) have drawn exceptional interest as they utilize pure spin current instead of charge current, which could promise ultra-low power consumption. However, relatively low efficiencies of spin injection, transport, and detection actually impede high-speed magnetization switching and challenge perspectives of ASLD. In this work, we study partial spin absorption induced magnetization switching in asymmetrical ASLD at the mesoscopic scale, in which the injector and detector have the nano-fabrication compatible device size (>100 nm) and their contact areas are different. The enlarged contact area of the detector is conducive to the spin current absorption, and the contact resistance difference between the injector and the detector can decrease the spin current backflow. Rigorous spin circuit modeling and micromagnetic simulations have been carried out to analyze the electrical and magnetic features. The results show that, at the fabrication-oriented technology scale, the ferromagnetic layer can hardly be switched by geometrically partial spin current absorption. The voltage-controlled magnetic anisotropy (VCMA) effect has been applied on the detector to accelerate the magnetization switching by modulating magnetic anisotropy of the ferromagnetic layer. With a relatively high VCMA coefficient measured experimentally, a voltage of 1.68 V can assist the whole magnetization switching within 2.8 ns. This analysis and improving approach will be of significance for future low-power, high-speed logic applications.

  14. Cost-effectiveness of left ventricular assist devices for patients with end-stage heart failure: analysis of the French hospital discharge database.

    Science.gov (United States)

    Tadmouri, Abir; Blomkvist, Josefin; Landais, Cécile; Seymour, Jerome; Azmoun, Alexandre

    2018-02-01

    Although left ventricular assist devices (LVADs) are currently approved for coverage and reimbursement in France, no French cost-effectiveness (CE) data are available to support this decision. This study aimed at estimating the CE of LVAD compared with medical management in the French health system. Individual patient data from the 'French hospital discharge database' (Medicalization of information systems program) were analysed using Kaplan-Meier method. Outcomes were time to death, time to heart transplantation (HTx), and time to death after HTx. A micro-costing method was used to calculate the monthly costs extracted from the Program for the Medicalization of Information Systems. A multistate Markov monthly cycle model was developed to assess CE. The analysis over a lifetime horizon was performed from the perspective of the French healthcare payer; discount rates were 4%. Probabilistic and deterministic sensitivity analyses were performed. Outcomes were quality-adjusted life years (QALYs) and incremental CE ratio (ICER). Mean QALY for an LVAD patient was 1.5 at a lifetime cost of €190 739, delivering a probabilistic ICER of €125 580/QALY [95% confidence interval: 105 587 to 150 314]. The sensitivity analysis showed that the ICER was mainly sensitive to two factors: (i) the high acquisition cost of the device and (ii) the device performance in terms of patient survival. Our economic evaluation showed that the use of LVAD in patients with end-stage heart failure yields greater benefit in terms of survival than medical management at an extra lifetime cost exceeding the €100 000/QALY. Technological advances and device costs reduction shall hence lead to an improvement in overall CE. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

  15. Ultra-thin titanium nanolayers for plasmon-assisted enhancement of bioluminescence of chloroplast in biological light emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Hsun Su, Yen [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Hsu, Chia-Yun; Chang, Chung-Chien [Science and Technology of Accelerator Light Source, Hsinchu 300, Taiwan (China); Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Tu, Sheng-Lung; Shen, Yun-Hwei [Department of Resource Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2013-08-05

    Ultra-thin titanium films were deposited via ultra-high vacuum ion beam sputter deposition. Since the asymmetric electric field of the metal foil plane matches the B-band absorption of chlorophyll a, the ultra-thin titanium nanolayers were able to generate surface plasmon resonance, thus enhancing the photoluminescence of chlorophyll a. Because the density of the states of plasmon resonance increases, the enhancement of photoluminescence also rises. Due to the biocompatibility and inexpensiveness of titanium, it can be utilized to enhance the bioluminescence of chloroplast in biological light emitting devices, bio-laser, and biophotonics.

  16. Walker devices and microswitch technology to enhance assisted indoor ambulation by persons with multiple disabilities: three single-case studies.

    Science.gov (United States)

    Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Sigafoos, Jeff; Oliva, Doretta; Campodonico, Francesca; Buono, Serafino

    2013-07-01

    These three single-case studies assessed the use of walker devices and microswitch technology for promoting ambulation behavior among persons with multiple disabilities. The walker devices were equipped with support and weight lifting features. The microswitch technology ensured that brief stimulation followed the participants' ambulation responses. The participants were two children (i.e., Study I and Study II) and one man (i.e., Study III) with poor ambulation performance. The ambulation efforts of the child in Study I involved regular steps, while those of the child in Study II involved pushing responses (i.e., he pushed himself forward with both feet while sitting on the walker's saddle). The man involved in Study III combined his poor ambulation performance with problem behavior, such as shouting or slapping his face. The results were positive for all three participants. The first two participants had a large increase in the number of steps/pushes performed during the ambulation events provided and in the percentages of those events that they completed independently. The third participant improved his ambulation performance as well as his general behavior (i.e., had a decline in problem behavior and an increase in indices of happiness). The wide-ranging implications of the results are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. To move as a human. Comment on "The embodiment of assistive devices-from wheelchair to exoskeleton" by M. Pazzaglia and M. Molinari

    Science.gov (United States)

    Papadimitriou, Christina

    2016-03-01

    I agree with the authors, that ;there have been very few attempts to develop user-centered medical technologies; [1] in the field of rehabilitation for persons with disabilities and wheelchair users in particular. The human-environment context in which humans plan and inhabit their actions as wheelchair users has not been extensively studied. The authors' unique work explores how a person embodies an exoskeleton (robotic legs or a wheelchair) in their everyday life and focuses on proprioception and brain's capacity to enlarge one's body schema in order to understand users' perspectives. Ultimately, Pazzaglia and Molinari wish to support persons who use assistive devices adapt and have successful, meaningful lives. The work is neuro-scientifically grounded, but doesn't forget the emotional or affective aspects of the user.

  18. A comparison of the health status and psychological distress of partners of patients with a left ventricular assist device versus an implantable cardioverter defibrillator

    DEFF Research Database (Denmark)

    Brouwers, Corline; Caliskan, Kadir; de Jonge, Nicolaas

    2014-01-01

    (F = 10.71, p = .001) but poorer mental health status (F = 14.82, p depression scores compared to ICD partners (F = 3.68, p = .05) at 6 months follow-up, also in adjusted analyses. There was no significant difference between groups on anxiety. CONCLUSION: Caregivers of LVAD......OBJECTIVE: To examine if the caregiving for patients with a left ventricular assist device (LVAD) is related to a poorer health status and more distress compared to patients with an implantable cardioverter defibrillator (ICD). BACKGROUND: Partners distress may influence patient outcomes...... and is therefore an important aspect in the care of LVAD and ICD patients. METHODS: Multi-center prospective observational study with 6 months follow-up of 33 LVAD partners (27% men; mean age = 54 ± 10 years) and 414 ICD partners (22% men; mean age = 60 ± 12 years). RESULTS: LVAD partners reported better physical...

  19. Using medical imaging for the detection of adverse events ("incidents") during the utilization of left ventricular assist devices in adult patients with advanced heart failure.

    Science.gov (United States)

    Kaufmann, Friedrich; Krabatsch, Thomas

    2016-05-01

    Ventricular assist devices (VAD) are used for mechanical support of the terminally failing heart. Failure of these life supporting systems can be fatal. Early and reliable detection of any upcoming problems is mandatory and is crucial for the outcome. Medical imaging methods are described within this review, which are not only essential for diagnosis of typically VAD-related complications but also for the detection or verification of technical issues. Within this review the utilization of medical imaging equipment for the diagnosis of technical malfunctions or damages of implanted system components is discussed. A newly developed specialized acoustic imaging method for pump thrombosis detection will also be described along with the most common VAD-related medical complications and their respective imaging methods and the limitations induced by the use of the VAD-system.

  20. Peptide aptamer-assisted immobilization of green fluorescent protein for creating biomolecule-complexed carbon nanotube device

    Science.gov (United States)

    Nii, Daisuke; Nozawa, Yosuke; Miyachi, Mariko; Yamanoi, Yoshinori; Nishihara, Hiroshi; Tomo, Tatsuya; Shimada, Yuichiro

    2017-10-01

    Carbon nanotubes are a novel material for next-generation applications. In this study, we generated carbon nanotube and green fluorescent protein (GFP) conjugates using affinity binding peptides. The carbon nanotube-binding motif was introduced into the N-terminus of the GFP through molecular biology methods. Multiple GFPs were successfully aligned on a single-walled carbon nanotube via the molecular recognition function of the peptide aptamer, which was confirmed through transmission electron microscopy and optical analysis. Fluorescence spectral analysis results also suggested that the carbon nanotube-GFP complex was autonomously formed with orientation and without causing protein denaturation during immobilization. This simple process has a widespread potential for fabricating carbon nanotube-biomolecule hybrid devices.

  1. Global Bi-ventricular endocardial distribution of activation rate during long duration ventricular fibrillation in normal and heart failure canines.

    Science.gov (United States)

    Luo, Qingzhi; Jin, Qi; Zhang, Ning; Han, Yanxin; Wang, Yilong; Huang, Shangwei; Lin, Changjian; Ling, Tianyou; Chen, Kang; Pan, Wenqi; Wu, Liqun

    2017-04-13

    The objective of this study was to detect differences in the distribution of the left and right ventricle (LV & RV) activation rate (AR) during short-duration ventricular fibrillation (SDVF, 1 min) in normal and heart failure (HF) canine hearts. Ventricular fibrillation (VF) was electrically induced in six healthy dogs (control group) and six dogs with right ventricular pacing-induced congestive HF (HF group). Two 64-electrode basket catheters deployed in the LV and RV were used for global endocardium electrical mapping. The AR of VF was estimated by fast Fourier transform analysis from each electrode. In the control group, the LV was activated faster than the RV in the first 20 s, after which there was no detectable difference in the AR between them. When analyzing the distribution of the AR within the bi-ventricles at 3 min of LDVF, the posterior LV was activated fastest, while the anterior was slowest. In the HF group, a detectable AR gradient existed between the two ventricles within 3 min of VF, with the LV activating more quickly than the RV. When analyzing the distribution of the AR within the bi-ventricles at 3 min of LDVF, the septum of the LV was activated fastest, while the anterior was activated slowest. A global bi-ventricular endocardial AR gradient existed within the first 20 s of VF but disappeared in the LDVF in healthy hearts. However, the AR gradient was always observed in both SDVF and LDVF in HF hearts. The findings of this study suggest that LDVF in HF hearts can be maintained differently from normal hearts, which accordingly should lead to the development of different management strategies for LDVF resuscitation.

  2. Medical staff radiation exposure in electrophysiology procedures: First results during biventricular ICD implantation

    International Nuclear Information System (INIS)

    Rossi, Pier Luca; Bianchini, David; Corazza, Ivan; Compagnone, Gaetano; Ferrari, Paolo; Gualdrini, Gianfranco; Zannoli, Romano

    2011-01-01

    Cardiac resynchronization therapy (CRT) requires a very long fluoroscopy time due to the need to monitor the placement of the device and electrodes inside the patient’s body at every step of the procedure. Aim of this study was to analyse staff X-ray exposure during the intervention, measuring H p (10) values with electronic dosimeters worn by medical staff. The scattered X-ray field was characterized using a spectrometric CdTe (cadmium-telluride) detector to define the radiation field impinging on the operator and thereby identify the correct dosimeter position for accurate measurement (i.e., above or under the shielding apron). In particular, knowledge of the X-ray spectrum yields information on photon flux and the energy distribution of the X-rays. Dosimetric data were then recorded in a series of 20 consecutive patients, obtaining a first set of H p (10) data that can be used to estimate the risk for the electrophysiologist performing this procedure.

  3. Computer assisted design of poly-silicon gated enhancement-mode, lateral double quantum dot devices for quantum computing

    Science.gov (United States)

    Bishop, Nathaniel; Young, Ralph; Borras Pinilla, Carlos; Stalford, Harold; Nielsen, Erik; Muller, Richard; Rahman, Rajib; Tracy, Lisa; Wendt, Joel; Lilly, Michael; Carroll, Malcolm

    2012-02-01

    We discuss trade-offs of different double quantum dot and charge sensor lay-outs using computer assisted design (CAD). We use primarily a semi-classical model, augmented with a self-consistent configuration interaction method. Although CAD for quantum dots is difficult due to uncontrolled factors (e.g., disorder), different ideal designs can still be compared. Comparisons of simulation and measured dot characteristics, such as capacitance, show that CAD can agree well with experiment for relevant cases. CAD results comparing several different designs will be discussed including a comparison to measurement results from the same designs. Trade-offs between poly-silicon and metal gate lay-outs will also be discussed. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  4. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides.

    Science.gov (United States)

    Wang, Ziming; Zhao, Xin; Xu, Xu; Wu, Lijie; Su, Rui; Zhao, Yajing; Jiang, Chengfei; Zhang, Hanqi; Ma, Qiang; Lu, Chunmei; Dong, Deming

    2013-01-14

    A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60°C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Provision and financing of assistive technology devices in Germany: a bureaucratic odyssey? The case of amyotrophic lateral sclerosis and Duchenne muscular dystrophy.

    Science.gov (United States)

    Henschke, Cornelia

    2012-05-01

    The regulations for financing assistive technology devices (ATDs) are complex and fragmented and, thus, might influence adequate provision of these devices to people who need multiple ATDs. This study aims to explore and analyze patients' problems with the provision and financing of ATDs for the following two rare diseases: amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD). A survey was conducted by means of semi-standardized questionnaires addressing the issues of coverage decisions for ATDs and problems with provision of ATDs. Information was retrieved from ALS (n=19) and DMD (n=14) patients. Conducted interviews were transcribed verbatim and analyzed using qualitative content analysis. Respondents experienced difficulties with the provision and financing of ATDs. They underlined problems such as long approval processes and a serious bureaucratic burden, which induced inadequate provision of ATDs. Experiences of ALS and DMD respondents frequently were similar, especially regarding financing decisions and the process of decision making by sickness funds. The results suggest that difficulties in receiving and financing ATDs are common problems among ALS and DMD patients. There is a need for an interdisciplinary approach in the provision of ATDs and their financing, which should be coordinated by case managers. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Effect of biventricular pacing on heart function evaluated by gated blood pool study in patients with end-stage heart failure

    International Nuclear Information System (INIS)

    Cholewinski, W.; Tarkowska, A.; Stefaniak, B.; Poniatowicz-Frasunek, E.; Kutarski, A.; Oleszczak, K.

    2002-01-01

    Biventricular cardiac pacing has been used as a complementary form of therapy in patients with severe heart failure. The aim of this study was to evaluate the effect of the synchronous stimulation of both ventricles on the heart function measured by gated blood pool study (GBP). Ten patients (9 men and 1 woman aged 53-74 years) with end-stage heart failure (HF) were studied. In all patients long-term biventricular pacing (BV) was applied. The obtained results were compared with single-chamber stimulation in 5 patients and with sinus rhythm (SR) in 8 patients. All patients underwent repeated GBP with RBC labelled with 740 MBq of 99m Tc-pertechnetate. The LVEF was calculated according to the standard method based on the count rates. Phase analysis was performed with the standard method using first Fourier element. Clinically in almost all patients moderate to important symptomatic improvement has been observed. The analysis of LVEF values revealed that BV pacing resulted in significantly higher values only in comparison with SR (21.6% ±10.3 v. 20.1% ± 10.1; p o± 29.6 v. 13.4 o± 37.6 and 7.4 o± 26.5 v. 6.0 o± 17.1, respectively). However, in comparison with LV pacing, BV stimulation revealed a change of dominant conduction abnormalities with a delay of RV contraction in relation to LV (9.0 o± 17.5 v. -3.0 o± 11.4). Biventricular pacing results in slight improvement of LVEF in patients with heart failure and can be considered a promising approach in patients with end-stage heart failure. Synchronous stimulation of both ventricles not always results in decrease of interventricular shift, however that observation requires further studies on a larger population. (author)

  7. Utilization of a biomedical device (VeinViewer® ) to assist with peripheral intravenous catheter (PIV) insertion for pediatric nurses.

    Science.gov (United States)

    McNeely, Heidi L; Ream, Theresa L; Thrasher, Jodi M; Dziadkowiec, Oliwier; Callahan, Tiffany J

    2018-04-01

    Vascular access in pediatric patients can be challenging even with the currently available technological resources. This nurse-driven research study explored time, cost, and resources for intravenous access to determine if a biomedical device, VeinViewer ® Vision, would facilitate improvements in pediatric access. In addition, this study looked at nurse perceptions of skills and confidence around intravenous insertion and if the use of the VeinViewer ® impacted these perceptions. Literature examining pediatric intravenous access success rates compared with nurse perceived skills and confidence is lacking. Nonblinded randomized control trial of pediatric nurses working in an acute care hospital setting. A preliminary needs assessment solicited feedback from nurses regarding their practice, perceived skills, and confidence with placing peripheral intravenous catheters (PIVs). Due to the results of the preliminary needs assessment, a research study was designed and 40 nurses were recruited to participate. The nurses were randomized into either a VeinViewer ® or standard practice group. Nurse participants placed intravenous catheters on hospitalized pediatric patients using established procedures while tracking data for the study. Needs assessment showed a majority of nurses felt a biomedical device would be helpful in building their intravenous insertion skills and their confidence. The study results did not demonstrate any clinically significant differences between VeinViewer ® use and standard practice for intravenous catheter insertion in pediatric patients for success of placement, number of attempts, or overall cost. In addition, no difference was noted between nurses in either group on perceived skills or confidence with insertion of PIVs. The ongoing need for resources focused on building nurse skills and confidence for PIV insertion was highlighted and organizations should continue to direct efforts toward developing skills and competency for staff that

  8. Short-term mechanical circulatory support as a bridge to durable left ventricular assist device implantation in refractory cardiogenic shock: a systematic review and meta-analysis.

    Science.gov (United States)

    den Uil, Corstiaan A; Akin, Sakir; Jewbali, Lucia S; Dos Reis Miranda, Dinis; Brugts, Jasper J; Constantinescu, Alina A; Kappetein, Arie Pieter; Caliskan, Kadir

    2017-07-01

    Short-term mechanical circulatory support (MCS) is increasingly used as a bridge to decision in patients with refractory cardiogenic shock. Subsequently, these patients might be bridged to durable MCS either as a bridge to candidacy/transplantation, or as destination therapy. The aim of this study was to review support duration and clinical outcome of short-term MCS in cardiogenic shock, and to analyse application of this technology as a bridge to long-term cardiac support (left ventricular assist device, LVAD) from 2006 till June 2016. Using Cochrane Register of Trials, Embase and Medline, a systematic review was performed on patients with cardiogenic shock from acute myocardial infarction, end-stage cardiomyopathy, or acute myocarditis, receiving short-term MCS. Studies on periprocedural, post-cardiotomy and cardiopulmonary resuscitation support were excluded. Thirty-nine studies, mainly registries of heterogeneous patient populations (n = 4151 patients), were identified. Depending on the device used (intra-aortic balloon pump, TandemHeart, Impella 2.5, Impella 5.0, CentriMag and peripheral veno-arterial extracorporeal membrane oxygenation), mean support duration was (range) 1.6-25 days and the mean proportion of short-term MCS patients discharged was (range) 45-66%. The mean proportion of bridge to durable LVAD was (range) 3-30%. Bridge to durable LVAD was most frequently performed in patients with end-stage cardiomyopathy (22 [12-35]%). We conclude that temporary MCS can be used to bridge patients with cardiogenic shock towards durable LVAD. Clinicians are encouraged to share their results in a large multicentre registry in order to investigate optimal device selection and best duration of support. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  9. The Role of Implantable Cardioverter Defibrillators in Patients Bridged to Transplantation with a Continuous Flow Left Ventricular Assist Device: A Propensity Score Matched Analysis

    Science.gov (United States)

    Clerkin, Kevin J.; Topkara, Veli K.; Mancini, Donna M.; Yuzefpolskaya, Melana; Demmer, Ryan T.; Dizon, Jose M.; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Colombo, Paolo C.; Garan, A. Reshad

    2016-01-01

    Background Implantable cardioverter defibrillators (ICD) provide a significant mortality benefit for appropriately selected patients with advanced heart failure. ICDs are associated with a mortality benefit when used in patients with a pulsatile left ventricular assist device (LVAD). However it is unclear whether patients with a continuous flow LVAD (CF-LVAD) derive the same benefit. This study sought to determine if the presence of an ICD provided a mortality benefit during CFLVAD support as a bridge to transplantation. Methods Patients were identified in the United Network for Organ Sharing (UNOS) registry that underwent LVAD implantation as bridge to transplantation from May 2004 and April 2014, with follow-up through June 2014. The primary outcome was freedom from death while on CF-LVAD support with adjustment for complications requiring UNOS listing status upgrade. Secondary endpoints included freedom from delisting while on CF-LVAD support and incidence of transplantation. Results 2,990 patients composed the study cohort and propensity score matching identified 1,012 patients with similar propensity scores. There was no difference in survival during device support between patients with and without an ICD (Hazard Ratio [HR] 1.20, 95% Confidence Interval [CI] 0.66-2.17, p=0.55). Adjusting for device complications requiring a UNOS listing status upgrade had minimal influence (HR 1.11, 95% CI 0.60-2.05, p=0.74). There was no increased risk of delisting due to being too sick for those with an ICD (HR 1.08, 95% CI 0.63-1.86, p=0.78). Likewise, the probability of transplantation was similar (HR 1.05, 95% CI 0.87-1.27, p=0.62). Conclusions Among patients bridged to transplantation with a CF-LVAD, the presence of an ICD did not reduce mortality. PMID:28089072

  10. The role of implantable cardioverter defibrillators in patients bridged to transplantation with a continuous-flow left ventricular assist device: A propensity score matched analysis.

    Science.gov (United States)

    Clerkin, Kevin J; Topkara, Veli K; Mancini, Donna M; Yuzefpolskaya, Melana; Demmer, Ryan T; Dizon, Jose M; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Colombo, Paolo C; Garan, A Reshad

    2017-06-01

    Implantable cardioverter defibrillators (ICDs) provide a significant mortality benefit for appropriately selected patients with advanced heart failure. ICDs are associated with a mortality benefit when used in patients with a pulsatile left ventricular assist device (LVAD). It is unclear whether patients with a continuous-flow LVAD (CF-LVAD) derive the same benefit. We sought to determine if the presence of an ICD provided a mortality benefit during CF-LVAD support as a bridge to transplantation. Patients were identified in the United Network for Organ Sharing (UNOS) registry who underwent LVAD implantation as bridge to transplantation between May 2004 and April 2014, with follow-up through June 2014. Primary outcome was freedom from death while on CF-LVAD support with adjustment for complications requiring UNOS listing status upgrade. Secondary end-points included freedom from delisting while on CF-LVAD support and incidence of transplantation. The study cohort comprised 2,990 patients, and propensity score matching identified 1,012 patients with similar propensity scores. There was no difference in survival during device support between patients with and without an ICD (hazard ratio [HR] = 1.20; 95% confidence interval [CI], 0.66-2.17; p = 0.55). Adjusting for device complications requiring a UNOS listing status upgrade had minimal influence (HR = 1.11; 95% CI, 0.60-2.05; p = 0.74). There was no increased risk of delisting owing to being too sick for patients with an ICD (HR = 1.08; 95% CI, 0.63-1.86; p = 0.78). Likewise, the probability of transplantation was similar (HR = 1.05; 95% CI, 0.87-1.27; p = 0.62). Among patients bridged to transplantation with a CF-LVAD, the presence of an ICD did not reduce mortality. Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  11. The Infant with Aortic Arch Hypoplasia and Small Left Heart Structures: Echocardiographic Indices of Mitral and Aortic Hypoplasia Predicting Successful Biventricular Repair.

    Science.gov (United States)

    Plymale, Jennifer M; Frommelt, Peter C; Nugent, Melodee; Simpson, Pippa; Tweddell, James S; Shillingford, Amanda J

    2017-08-01

    In infants with aortic arch hypoplasia and small left-sided cardiac structures, successful biventricular repair is dependent on the adequacy of the left-sided structures. Defining accurate thresholds of echocardiographic indices predictive of successful biventricular repair is paramount to achieving optimal outcomes. We sought to identify pre-operative echocardiographic indices of left heart size that predict intervention-free survival in infants with small left heart structures undergoing primary aortic arch repair to establish biventricular circulation (BVC). Infants ≤2 months undergoing aortic arch repair from 1999 to 2010 with aortic and/or mitral valve hypoplasia, (Z-score ≤-2) were included. Pre-operative and follow-up echocardiograms were reviewed. Primary outcome was successful biventricular circulation (BVC), defined as freedom from death, transplant, or single ventricular conversion at 1 year. Need for catheter based or surgical re-intervention (RI), valve annular growth, and significant late aortic or mitral valve obstruction were additional outcomes. Fifty one of 73 subjects (79%) had successful BVC and were free of RI at 1 year. Seven subjects failed BVC; four of those died. The overall 1 year survival for the cohort was 95%. Fifteen subjects underwent a RI but maintained BVC. In univariate analysis, larger transverse aorta (p = 0.006) and aortic valve (p = 0.02) predicted successful BVC without RI. In CART analysis, the combination of mitral valve (MV) to tricuspid valve (TV) ratio ≤0.66 with an aortic valve (AV) annulus Z-score ≤-3 had the greatest power to predict BVC failure (sensitivity 71%, specificity 94%). In those with successful BVC, the combination of both AV and MV Z-score ≤-2.5 increased the odds of RI (OR 3.8; CI 1.3-11.4). Follow-up of non-RI subjects revealed improvement in AV and MV Z-score (median AV annulus changed over time from -2.34 to 0.04 (p indices. In this complex population, 1 year survival is high, but

  12. Pulsed ion-beam assisted deposition of Ge nanocrystals on SiO2 for non-volatile memory device

    International Nuclear Information System (INIS)

    Stepina, N.P.; Dvurechenskii, A.V.; Armbrister, V.A.; Kirienko, V.V.; Novikov, P.L.; Kesler, V.G.; Gutakovskii, A.K.; Smagina, Z.V.; Spesivtzev, E.V.

    2008-01-01

    A floating gate memory structure, utilizing Ge nanocrystals (NCs) deposited on tunnel SiO 2 , have been fabricated using pulsed low energy ion-beam induced molecular-beam deposition (MBD) in ultra-high vacuum. The ion-beam action is shown to stimulate the nucleation of Ge NCs when being applied after thin Ge layer deposition. Growth conditions for independent change of NCs size and array density were established allowing to optimize the structure parameters required for memory device. Activation energy E = 0.25 eV was determined from the temperature dependence of NCs array density. Monte Carlo simulation has shown that the process, determining NCs array density, is the surface diffusion. Embedding of the crystalline Ge dots into silicon oxide was carried out by selective oxidation of Si(100)/SiO 2 /Ge(NCs)/poly-Si structure. MOS-capacitor obtained after oxidation showed a hysteresis in its C-V curves attributed to charge retention in the Ge dots

  13. Model of a thermal energy storage device integrated into a solar assisted heat pump system for space heating

    International Nuclear Information System (INIS)

    Badescu, Viorel

    2003-01-01

    Details about modelling a sensible heat thermal energy storage (TES) device integrated into a space heating system are given. The two main operating modes are described. Solar air heaters provide thermal energy for driving a vapor compression heat pump. The TES unit ensures a more efficient usage of the collected solar energy. The TES operation is modeled by using two non-linear coupled partial differential equations for the temperature of the storage medium and heat transfer fluid, respectively. Preliminary results show that smaller TES units provide a higher heat flux to the heat pump vaporiser. This makes the small TES unit discharge more rapidly during time periods with higher thermal loads. The larger TES units provide heat during longer time periods, even if the heat flux they supply is generally smaller. The maximum heat flux is extracted from the TES unit during the morning. Both the heat pump COP and exergy efficiency decrease when the TES unit length increases. Also, the monthly thermal energy stored by the TES unit and the monthly energy necessary to drive the heat pump compressor are increased by increasing the TES unit length

  14. Switching Vertical to Horizontal Graphene Growth Using Faraday Cage-Assisted PECVD Approach for High-Performance Transparent Heating Device.

    Science.gov (United States)

    Qi, Yue; Deng, Bing; Guo, Xiao; Chen, Shulin; Gao, Jing; Li, Tianran; Dou, Zhipeng; Ci, Haina; Sun, Jingyu; Chen, Zhaolong; Wang, Ruoyu; Cui, Lingzhi; Chen, Xudong; Chen, Ke; Wang, Huihui; Wang, Sheng; Gao, Peng; Rummeli, Mark H; Peng, Hailin; Zhang, Yanfeng; Liu, Zhongfan

    2018-02-01

    Plasma-enhanced chemical vapor deposition (PECVD) is an applicable route to achieve low-temperature growth of graphene, typically shaped like vertical nanowalls. However, for transparent electronic applications, the rich exposed edges and high specific surface area of vertical graphene (VG) nanowalls can enhance the carrier scattering and light absorption, resulting in high sheet resistance and low transmittance. Thus, the synthesis of laid-down graphene (LG) is imperative. Here, a Faraday cage is designed to switch graphene growth in PECVD from the vertical to the horizontal direction by weakening ion bombardment and shielding electric field. Consequently, laid-down graphene is synthesized on low-softening-point soda-lime glass (6 cm × 10 cm) at ≈580 °C. This is hardly realized through the conventional PECVD or the thermal chemical vapor deposition methods with the necessity of high growth temperature (1000 °C-1600 °C). Laid-down graphene glass has higher transparency, lower sheet resistance, and much improved macroscopic uniformity when compare to its vertical graphene counterpart and it performs better in transparent heating devices. This will inspire the next-generation applications in low-cost transparent electronics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Single-center experience of the bridge-to-bridge strategy using the Nipro paracorporeal ventricular assist device.

    Science.gov (United States)

    Yoshitake, Shuichi; Kinoshita, Osamu; Nawata, Kan; Hoshino, Yasuhiro; Itoda, Yoshifumi; Kimura, Mitsutoshi; Yamauchi, Haruo; Ono, Minoru

    2018-06-25

    Currently, we use the Nipro paracorporeal VAD (p-VAD) for initial short-term ventricular support, as a bridge to decision (BTD) or a bridge to candidacy (BTC) treatment, in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) levels 1 and 2 patients. However, it is possible that compared to patients with primary implantable-VADs (P-iVAD), the bridge-to-bridge (BTB) patients are more likely to develop complications. This retrospective study used data from 24 consecutive BTB patients who were initially implanted with Nipro p-VAD as BTD or BTC treatments between April 2011 and March 2016, and subsequently underwent conversion to an i-VAD. The data from 72 patients who underwent a primary i-VAD (P-iVAD) procedure were used for comparison. Between the two groups, there was no significant difference in the incidence of infectious events (p = 0.72) or stroke (p = 0.44). Orthotropic heart transplantation was performed in 6 of the 24 patients in the BTB group and in 21 of the 72 patients in the P-iVAD group. The 1- and 2-year survival rates were 95.8% and 95.8% in the BTB group and 91% and 85.8% in the P-iVAD group; these values were not significantly different between groups (p = 0.91). Based on these results we conclude that BTB using Nipro p-VAD is a reasonable strategy for treating patients with severe decompensated end-stage heart failure.

  16. Lanthanide-Assisted Deposition of Strongly Electro-optic PZT Thin Films on Silicon: Toward Integrated Active Nanophotonic Devices.

    Science.gov (United States)

    George, J P; Smet, P F; Botterman, J; Bliznuk, V; Woestenborghs, W; Van Thourhout, D; Neyts, K; Beeckman, J

    2015-06-24

    The electro-optical properties of lead zirconate titanate (PZT) thin films depend strongly on the quality and crystallographic orientation of the thin films. We demonstrate a novel method to grow highly textured PZT thin films on silicon using the chemical solution deposition (CSD) process. We report the use of ultrathin (5-15 nm) lanthanide (La, Pr, Nd, Sm) based intermediate layers for obtaining preferentially (100) oriented PZT thin films. X-ray diffraction measurements indicate preferentially oriented intermediate Ln2O2CO3 layers providing an excellent lattice match with the PZT thin films grown on top. The XRD and scanning electron microscopy measurements reveal that the annealed layers are dense, uniform, crack-free and highly oriented (>99.8%) without apparent defects or secondary phases. The EDX and HRTEM characterization confirm that the template layers act as an efficient diffusion barrier and form a sharp interface between the substrate and the PZT. The electrical measurements indicate a dielectric constant of ∼650, low dielectric loss of ∼0.02, coercive field of 70 kV/cm, remnant polarization of 25 μC/cm(2), and large breakdown electric field of 1000 kV/cm. Finally, the effective electro-optic coefficients of the films are estimated with a spectroscopic ellipsometer measurement, considering the electric field induced variations in the phase reflectance ratio. The electro-optic measurements reveal excellent linear effective pockels coefficients of 110 to 240 pm/V, which makes the CSD deposited PZT thin film an ideal candidate for Si-based active integrated nanophotonic devices.

  17. The Impact of Obesity on Patients Bridged to Transplantation with Continuous-Flow Left Ventricular Assist Devices

    Science.gov (United States)

    Clerkin, Kevin J.; Naka, Yoshifumi; Mancini, Donna M.; Colombo, Paolo C.; Topkara, Veli K.

    2017-01-01

    Objectives This study sought to determine if obese patients had worse post-LVAD implantation outcomes and if the implantation of an LVAD allowed for weight loss. Background Obesity is a risk factor for cardiovascular disease including heart failure. Obese heart failure patients have better outcomes than those with normal weight; however obese patients have worse outcomes following heart transplantation. Methods Patients were identified in the UNOS database that underwent LVAD implantation as bridge to transplantation from May 2004 and April 2014, with follow-up through June 2014. Patients were grouped according to BMI based on the WHO classification Results Among 3,856 patients the risk of death or delisting was not significantly different between BMI groups (p=0.347). There was no increased risk of death (p=0.234) or delisting (p=0.918). The risk of complication requiring UNOS status upgrade was increased for those with Class II obesity or greater (HR 1.48, 95% CI 1.14–1.93, p=0.004), driven by increased infection and thromboembolism. Obese patients had worse post-transplant outcomes. Weight loss substantial enough to decrease BMI group was achieved by a small proportion of patients listed with Class I obesity or greater (9.6–15.5%). Conclusions Patients with obesity had similar freedom from death or delisting while on LVAD support. However, Class II obese or greater patients had an increased risk of complications requiring UNOS status upgrade compared with those with normal BMI during LVAD support and decreased post-transplant survival. Weight loss on device therapy was possible, but uncommon. Careful consideration is needed when a bridge to weight loss strategy is proposed. PMID:27614942

  18. The Impact of Socioeconomic Status on Patients Supported with a Left Ventricular Assist Device: An Analysis of the UNOS Database

    Science.gov (United States)

    Clerkin, Kevin J.; Garan, A. Reshad; Wayda, Brian; Givens, Raymond C.; Yuzefpolskaya, Melana; Nakagawa, Shunichi; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Mancini, Donna M.; Colombo, Paolo C.; Topkara, Veli K.

    2016-01-01

    Background Low socioeconomic status (SES) is a known risk factor for heart failure, mortality among those with heart failure, and poor post heart transplant (HT) outcomes. This study sought to determine if SES is associated with decreased waitlist survival while on LVAD support and after HT. Methods and Results 3,361 adult patients bridged to primary HT with an LVAD between May 2004 and April 2014 were identified in the UNOS database. SES was measured using the AHRQ SES index using data from the 2014 American Community Survey. In the study cohort, SES did not have an association with the combined endpoint of death or delisting on LVAD support (p=0.30). In a cause-specific unadjusted model, those in the top (HR 1.55, 95% CI 1.14–2.11, p=0.005) and second greatest SES quartile (HR 1.50, 95% CI 1.10–2.04, p=0.01) had an increased risk of death on device support compared to the lowest SES quartile. Adjusting for clinical risk factors mitigated the increased risk. There was no association between SES and complications. Post-HT survival, both crude and adjusted, was decreased for patients in the lowest quartile of SES index compared to all other SES quartiles. Conclusions Freedom from waitlist death or delisting was not impacted by SES. Patients with a higher SES had an increased unadjusted risk of waitlist mortality during LVAD support, which was mitigated by adjusting for increased comorbid conditions. Low SES was associated with worse post-HT outcomes. Further study is needed to confirm and understand a differential effect of SES on post-transplant outcomes that was not seen during LVAD support prior to HT. PMID:27758810

  19. Devices for hearing loss

    Science.gov (United States)

    ... the sounds you want to hear. Assistive listening devices bring certain sounds directly to your ears. This can ... a small room or on a stage. Other devices can bring the sound from your TV, radio, or music ...

  20. Large-Animal Biventricular Working Heart Perfusion System with Low Priming Volume-Comparison between in vivo and ex vivo Cardiac Function.

    Science.gov (United States)

    Abicht, Jan-Michael; Mayr, Tanja Axinja Jelena; Jauch, Judith; Guethoff, Sonja; Buchholz, Stefan; Reichart, Bruno; Bauer, Andreas

    2018-01-01

    Existing large-animal, ex vivo, cardiac perfusion models are restricted in their ability to establish an ischemia/reperfusion condition as seen in cardiac surgery or transplantation. Other working heart systems only challenge one ventricle or require a substantially larger priming volume. We describe a novel biventricular cardiac perfusion system with reduced priming volume. Juvenile pig hearts were cardiopleged, explanted, and reperfused ex vivo after 150 minutes of cold ischemia. Autologous whole blood was used as perfusate (minimal priming volume 350 mL). After 15 minutes of Langendorff perfusion (LM), the system was switched into a biventricular working mode (WM) and studied for 3 hours. During reperfusion, complete unloading of both ventricles and constant-pressure coronary perfusion was achieved. During working mode perfusion, the preload and afterload pressure of both ventricles was controlled within the targeted physiologic range. Functional parameters such as left ventricular work index were reduced in ex vivo working mode (in vivo: 787 ± 186 vs. 1 h WM 498 ± 66 mm Hg·mL/g·min; p  hours while functional and blood parameters are easily accessible. Moreover, because of the minimal priming volume, the novel ex vivo cardiac perfusion circuit allows for autologous perfusion, using the limited amount of blood available from the organ donating animal. Georg Thieme Verlag KG Stuttgart · New York.

  1. Implantable Cardioverter-Defibrillators in Patients With a Continuous-Flow Left Ventricular Assist Device: An Analysis of the INTERMACS Registry.

    Science.gov (United States)

    Clerkin, Kevin J; Topkara, Veli K; Demmer, Ryan T; Dizon, Jose M; Yuzefpolskaya, Melana; Fried, Justin A; Mai, Xingchen; Mancini, Donna M; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Colombo, Paolo C; Garan, A Reshad

    2017-12-01

    This study sought to determine if the presence of implantable cardioverter-defibrillators (ICD) provided a mortality benefit during continuous-flow left ventricular assist device (LVAD) support. An ICD decreases mortality in selected patients with advanced heart failure and have been associated with reduced mortality in patients with pulsatile LVAD. However, it is unclear whether that benefit extends to patients with a contemporary continuous-flow LVAD. Propensity score matching was used to generate a cohort of patients with similar baseline characteristics. The primary outcome was freedom from death during LVAD support. Secondary endpoints included freedom from unexpected death, likelihood of transplantation and recovery, and adverse events. Among 16,384 eligible patients in the Interagency Registry for Mechanically Assisted Circulatory Support registry, 2,209 patients with an ICD and 2,209 patients without one had similar propensity scores and were included. The presence of an ICD was associated with an increased mortality risk (hazard ratio: 1.20; 95% confidence interval [CI]: 1.04 to 1.39; p = 0.013) and an increased risk of unexpected death during device support (HR: 1.33; 95% CI: 1.03 to 1.71; p = 0.03). Patients with an ICD were more likely to undergo transplantation (HR: 1.16; 95% CI: 0.99 to 1.35; p = 0.06) and less likely to have LVAD explant for recovery (HR: 0.53, 95% CI: 0.29 to 0.98; p = 0.04). Patients with an ICD had a higher rate of treated ventricular arrhythmias (rate ratio: 1.27; 95% CI: 1.10 to 1.48; p = 0.001) and rehospitalization (rate ratio: 1.08; 95% CI: 1.04 to 1.12; p < 0.0001), but rates of hemorrhagic stroke were similar (rate ratio: 1.01; 95% CI: 0.81 to 1.26; p = 0.98). Among patients with a continuous flow LVAD, the presence of an ICD was not associated with reduced mortality. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  2. Decision making for destination therapy left ventricular assist devices: "there was no choice" versus "I thought about it an awful lot".

    Science.gov (United States)

    McIlvennan, Colleen K; Allen, Larry A; Nowels, Carolyn; Brieke, Andreas; Cleveland, Joseph C; Matlock, Daniel D

    2014-05-01

    Destination therapy left ventricular assist devices (DT LVADs) are one of the most invasive medical interventions for end-stage illness. How patients decide whether or not to proceed with device implantation is unknown. We aimed to understand the decision-making processes of patients who either accept or decline DT LVADs. Between October 2012 and September 2013, we conducted semistructured, in-depth interviews to understand patients' decision-making experiences. Data were analyzed using a mixed inductive and deductive approach. Twenty-two eligible patients were interviewed, 15 with DT LVADs and 7 who declined. We found a strong dichotomy between decision processes with some patients (11 accepters) being automatic and others (3 accepters, 7 decliners) being reflective in their approach to decision making. The automatic group was characterized by a fear of dying and an over-riding desire to live as long as possible: "[LVAD] was the only option I had…that or push up daisies…so I automatically took this." By contrast, the reflective group went through a reasoned process of weighing risks, benefits, and burdens: "There are worse things than death." Irrespective of approach, most patients experienced the DT LVAD decision as a highly emotional process and many sought support from their families or spiritually. Some patients offered a DT LVAD face the decision by reflecting on a process and reasoning through risks and benefits. For others, the desire to live supersedes such reflective processing. Acknowledging this difference is important when considering how to support patients who are faced with this complex decision. © 2014 American Heart Association, Inc.

  3. Decision Making for Destination Therapy Left Ventricular Assist Devices: “There was no choice” versus “I thought about it an awful lot”

    Science.gov (United States)

    McIlvennan, Colleen K.; Allen, Larry A.; Nowels, Carolyn; Brieke, Andreas; Cleveland, Joseph C.; Matlock, Daniel D.

    2014-01-01

    Background Destination therapy left ventricular assist devices (DT LVAD) are one of the most invasive medical interventions for end-stage illness. How patients decide whether or not to proceed with device implantation is unknown. We aimed to understand the decision-making processes of patients who either accept or decline DT LVADs. Methods and Results Between October 2012–September 2013, we conducted semi-structured, in-depth interviews to understand patients’ decision-making experiences. Data were analyzed using a mixed inductive and deductive approach. Twenty-two eligible patients were interviewed, 15 with DT LVADs and 7 who declined. We found a strong dichotomy between decision processes with some patients (11 accepters) being “automatic” and others (3 accepters, 7 decliners) being “reflective” in their approach to decision making. The automatic group was characterized by a fear of dying and an overriding desire to live as long as possible: “[LVAD] was the only option I had…that or push up daisies…so I automatically took this”. In contrast, the reflective group went through a reasoned process of weighing risks, benefits, and burdens: “There are worse things than death.” Irrespective of approach, most patients experienced the DT LVAD decision as a highly emotional process and many sought support from their families or spiritually. Conclusion Some patients offered a DT LVAD face the decision by reflecting on a process and reasoning through risks and benefits. For others, the desire to live supersedes such reflective processing. Acknowledging this difference is important when considering how to support patients who are faced with this complex decision. PMID:24823949

  4. De novo aortic insufficiency during long-term support on a left ventricular assist device: a systematic review and meta-analysis.

    Science.gov (United States)

    Deo, Salil V; Sharma, Vikas; Cho, Yang Hyun; Shah, Ishan K; Park, Soon J

    2014-01-01

    Aortic insufficiency (AI) may occur while supported on a left ventricular assist device (LVAD). We conducted a systematic review to determine the incidence, predictors, and consequences of AI during LVAD support. MEDLINE was searched for original studies presenting clinical data regarding patients who developed AI during LVAD implant. Seven observational studies (657 patients) were selected for review; 65% of patients underwent implantation with a continuous-flow device (Cf-LVAD). The incidence of AI was 25% (11-42%) (Support period: 412 ± 281 days). AI increased by 4% (1-6%) per month of support (p < 0.01). AI-positive patients were older at implant (weighted mean difference, 7.7 [4.3; 11.1]; p < 0.01). Female sex (0.002 ± 0.001; p = 0.01) and smaller body surface area (-0.003 ± 0.001 per m; p < 0.01) correlated with progressive AI. Destination therapy patients (odds ratio [OR], 5.3 [1.2, 24]; p = 0.02) and those with Cf-LVAD pumps were likely to develop AI (hazard ratio [HR], 2.2 [1.2, 3.8]; p < 0.01). A closed aortic valve was associated with AI (OR, 4.7 [1.9, 11.8]; p < 0.01). Survival was comparable in both cohorts (HR, 1.5 [0.81, 2.8]; p = 0.2). A significant number of patients develop de novo AI during LVAD support. Advanced age, longer support duration, continuous-flow pumps, and a closed aortic valve are associated with AI. Large cohort studies would improve our understanding of this condition.

  5. Pre- and post-operative risk factors associated with cerebrovascular accidents in patients supported by left ventricular assist device. -Single center's experience in japan-.

    Science.gov (United States)

    Nakajima, Ikutaro; Kato, Tomoko S; Komamura, Kazuo; Takahashi, Ayako; Oda, Noboru; Sasaoka, Taro; Asakura, Masanori; Hashimura, Kazuhiko; Kitakaze, Masafumi

    2011-01-01

    Cerebrovascular accident (CVA) is a major adverse event following left ventricular assist device (LVAD) surgery. This study investigates pre- and post-operative factors associated with CVA in this population. A total of 118 consecutive patients who underwent LVAD surgery at our institution between April 1994 and April 2009 were retrospectively reviewed. Clinical characteristics, hemodynamic data, and laboratory indexes associated with CVA after LVAD surgery were analyzed. In total, 57 (48.3%) patients developed CVA 133.5 ± 184.7 days after surgery. The combination of baseline heart disease, type of LVAD surgery, mean right atrial pressure (mRA), serum total bilirubin and total protein concentration, and right ventricular end-diastolic dimension (RVEDd) was associated with CVA at any time after LVAD surgery, with a discriminant probability of 718%. With regard to CVA development later than 3 months after surgery, the combination of mRA and RVEDd before surgery [odds ratio (OR), 1.24, 1.20; 95% confidential interval (CI), 1.07-1.42, 1.06-1.34; P = 0.004, P = 0.006, respectively], positive blood culture, and C-reactive protein after surgery (OR, 7.66, 2.19; 95%CI, 1.50-39.0, 1.47-3.25; P = 0.015, P < 0.0001, respectively) was associated with CVA with a discriminant probability of 85.9%. Patients' general condition including malnutrition, in addition to device selection, contributed to overall CVA development after surgery. In the chronic phase after surgery, pre-LVAD right heart failure and post-LVAD systemic infection were highly associated with CVA development.

  6. Ambient hemolysis and activation of coagulation is different between HeartMate II and HeartWare left ventricular assist devices.

    Science.gov (United States)

    Birschmann, Ingvild; Dittrich, Marcus; Eller, Thomas; Wiegmann, Bettina; Reininger, Armin J; Budde, Ulrich; Strüber, Martin

    2014-01-01

    Thromboembolic and bleeding events in patients with a left ventricular assist device (LVAD) are still a major cause of complications. Therefore, the balance between anti-coagulant and pro-coagulant factors needs to be tightly controlled. The principle hypothesis of this study is that different pump designs may have an effect on hemolysis and activation of the coagulation system. Referring to this, the HeartMate II (HMII; Thoratec Corp, Pleasanton, CA) and the HeartWare HVAD (HeartWare International Inc, Framingham, MA) were investigated. For 20 patients with LVAD support (n = 10 each), plasma coagulation, full blood count, and clinical chemistry parameters were measured. Platelet function was monitored using platelet aggregometry, platelet function analyzer-100 system ( Siemens, Marburg, Germany), vasodilator-stimulated phosphoprotein phosphorylation assay, immature platelet fraction, platelet-derived microparticles, and von Willebrand diagnostic. Acquired von Willebrand syndrome could be detected in all patients. Signs of hemolysis, as measured by lactate dehydrogenase levels (mean, 470 U/liter HMII, 250 U/liter HVAD; p < 0.001), were more pronounced in the HMII patients. In contrast, D-dimer analysis indicated a significantly higher activation of the coagulation system in HVAD patients (mean, 0.94 mg/liter HMII, 2.01 mg/liter HVAD; p < 0.01). The efficacy of anti-platelet therapy using clopidogrel was not sufficient in more than 50% of the patients. Our results support the finding that all patients with rotary blood pumps suffered from von Willebrand syndrome. In addition, a distinct footprint of effects on hemolysis and the coagulation system can be attributed to different devices. As a consequence, the individual status of the coagulation system needs to be controlled in long-term patients. © 2013 Published by International Society for the Heart and Lung Transplantation on behalf of International Society for Heart and Lung Transplantation.

  7. The Impact of Obesity on Patients Bridged to Transplantation With Continuous-Flow Left Ventricular Assist Devices.

    Science.gov (United States)

    Clerkin, Kevin J; Naka, Yoshifumi; Mancini, Donna M; Colombo, Paolo C; Topkara, Veli K

    2016-10-01

    This study sought to determine if obese patients had worse post-left ventricular assist device (LVAD) implantation outcomes and if the implantation of an LVAD allowed for weight loss. Obesity is a risk factor for cardiovascular disease including heart failure. Obese heart failure patients have better outcomes than those with normal weight; however, obese patients have worse outcomes after heart transplantation. Patients were identified in the United Network for Organ Sharing (UNOS) database that underwent LVAD implantation as bridge to transplantation from May 2004 and April 2014, with follow-up through June 2014. Patients were grouped according to body mass index (BMI) based on the World Health Organization classification. Among 3,856 patients, the risk of death or delisting was not significantly different between BMI groups (p = 0.347). There was no increased risk of death (p = 0.234) or delisting (p = 0.918). The risk of complication requiring UNOS status upgrade was increased for those with class II obesity or greater (hazard ratio: 1.48; p = 0.004), driven by increased infection and thromboembolism. Obese patients had worse post-transplantation outcomes. Weight loss substantial enough to decrease BMI group was achieved by a small proportion of patients listed with class I obesity or greater (9.6% to 15.5%). Patients with obesity had similar freedom from death or delisting while on LVAD support. However, class II obese or greater patients had an increased risk of complications requiring UNOS status upgrade compared with those with normal BMI during LVAD support and decreased post-transplantation survival. Weight loss on device therapy was possible, but uncommon. Careful consideration is needed when a bridge to weight loss strategy is proposed. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  8. Impact of Socioeconomic Status on Patients Supported With a Left Ventricular Assist Device: An Analysis of the UNOS Database (United Network for Organ Sharing).

    Science.gov (United States)

    Clerkin, Kevin J; Garan, Arthur Reshad; Wayda, Brian; Givens, Raymond C; Yuzefpolskaya, Melana; Nakagawa, Shunichi; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Mancini, Donna M; Colombo, Paolo C; Topkara, Veli K

    2016-10-01

    Low socioeconomic status (SES) is a known risk factor for heart failure, mortality among those with heart failure, and poor post heart transplant (HT) outcomes. This study sought to determine whether SES is associated with decreased waitlist survival while on left ventricular assist device (LVADs) support and after HT. A total of 3361 adult patients bridged to primary HT with an LVAD between May 2004 and April 2014 were identified in the UNOS database (United Network for Organ Sharing). SES was measured using the Agency for Healthcare Research and Quality SES index using data from the 2014 American Community Survey. In the study cohort, SES did not have an association with the combined end point of death or delisting on LVAD support (P=0.30). In a cause-specific unadjusted model, those in the top (hazard ratio, 1.55; 95% confidence interval, 1.14-2.11; P=0.005) and second greatest SES quartile (hazard ratio 1.50; 95% confidence interval, 1.10-2.04; P=0.01) had an increased risk of death on device support compared with the lowest SES quartile. Adjusting for clinical risk factors mitigated the increased risk. There was no association between SES and complications. Post-HT survival, both crude and adjusted, was decreased for patients in the lowest quartile of SES index compared with all other SES quartiles. Freedom from waitlist death or delisting was not affected by SES. Patients with a higher SES had an increased unadjusted risk of waitlist mortality during LVAD support, which was mitigated by adjusting for increased comorbid conditions. Low SES was associated with worse post-HT outcomes. Further study is needed to confirm and understand a differential effect of SES on post-transplant outcomes that was not seen during LVAD support before HT. © 2016 American Heart Association, Inc.

  9. Comparison of early versus delayed timing of left ventricular assist device implantation as a bridge-to-transplantation: An analysis of the UNOS dataset.

    Science.gov (United States)

    Kitada, Shuichi; Schulze, P Christian; Jin, Zhezhen; Clerkin, Kevin; Homma, Shunichi; Mancini, Donna M

    2016-01-15

    Placement of left ventricular assist devices (LVAD) as a bridge-to-heart transplantation (HTx) has rapidly expanded due to organ donor shortage. However, the timing of LVAD implantation is variable and it remains unclear if earlier implantation improves survival. We analyzed 14,187 adult candidates from the United Network of Organ Sharing database. Patients were classified by 3 treatment strategies including patients medically treated alone (MED, n=11,009), patients on LVAD support at listing (Early-LVAD, n=1588) and patients undergoing LVAD placement while awaiting HTx (Delayed-LVAD, n=1590). Likelihood of HTx and event-free survival were assessed in patients subcategorized by clinical strategies and UNOS status at listing. The device support strategy, despite the timing of placement, was not associated with increased likelihood of HTx compared to MED group. However, both LVAD implantation strategies showed better survival compared to MED group (Early-LVAD: HR 0.811 and 0.633, 95% CI 0.668-0.984 and 0.507-0.789, for 1A and 1B; p=0.034 and p<0.001, Delayed-LVAD: HR 0.553 and 0.696, 95% CI 0.415-0.736 and 0.571-0.847, for 1A and 1B; both p<0.001, respectively). Furthermore, there was no significant difference in survival between these LVAD implantation strategies in patients listed as 1B (p=0.500), although Early-LVAD implantation showed worse survival in patients listed as 1A (HR 1.467, 95% CI 1.076-2.000; p=0.015). LVAD support strategies offer a safe bridge-to-HTx. Those candidates who receive urgent upfront LVAD implantation for HTx, and improve to 1B status, would achieve competitive survival with those who receive elective LVAD implantation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Influence of surgical implantation angle of left ventricular assist device outflow graft and management of aortic valve opening on the risk of stroke in heart failure patients

    Science.gov (United States)

    Chivukula, V. Keshav; McGah, Patrick; Prisco, Anthony; Beckman, Jennifer; Mokadam, Nanush; Mahr, Claudius; Aliseda, Alberto

    2016-11-01

    Flow in the aortic vasculature may impact stroke risk in patients with left ventricular assist devices (LVAD) due to severely altered hemodynamics. Patient-specific 3D models of the aortic arch and great vessels were created with an LVAD outflow graft at 45, 60 and 90° from centerline of the ascending aorta, in order to understand the effect of surgical placement on hemodynamics and thrombotic risk. Intermittent aortic valve opening (once every five cardiac cycles) was simulated and the impact of this residual native output investigated for the potential to wash out stagnant flow in the aortic root region. Unsteady CFD simulations with patient-specific boundary conditions were performed. Particle tracking for 10 cardiac cycles was used to determine platelet residence times and shear stress histories. Thrombosis risk was assessed by a combination of Eulerian and Lagrangian metrics and a newly developed thrombogenic potential metric. Results show a strong influence of LVAD outflow graft angle on hemodynamics in the ascending aorta and consequently on stroke risk, with a highly positive impact of aortic valve opening, even at low frequencies. Optimization of LVAD implantation and management strategies based on patient-specific simulations to minimize stroke risk will be presented

  11. The Vacuum-Assisted Closure (VAC) device for hastened attachment of a superficial inferior-epigastric flap to third-degree burns on hand and fingers.

    Science.gov (United States)

    Weinand, Christian

    2009-01-01

    The vacuum-assisted closure (VAC) device has a wide range of clinical applications, including treatment of infected surgical wounds, traumatic wounds, pressure ulcers, wounds with exposed bone and hardware, diabetic foot ulcers, and venous stasis ulcers. Increased release of growth factors has been described, leading to improved vascularization and thereby formation of new tissue. The system is also used in burn surgery for reconstructive purposes. In this case report, a patient suffered from a third-degree burn injury to the dorsum of the hand with exposure of tendons, necessitating the use of a flap reconstruction. The patient was treated with a superficial inferior-epigastric artery-based flap and the VAC system was applied in a created glove-like shape. Hastened attachment of the flap onto the exposed fingers was observed after 4 days. The author reports on the additional use of the VAC system to hasten flap attachment in a patient with a burn injury to the dorsum of the hand.

  12. Benefits of incorporating the adaptive dynamic range optimization amplification scheme into an assistive listening device for people with mild or moderate hearing loss.

    Science.gov (United States)

    Chang, Hung-Yue; Luo, Ching-Hsing; Lo, Tun-Shin; Chen, Hsiao-Chuan; Huang, Kuo-You; Liao, Wen-Huei; Su, Mao-Chang; Liu, Shu-Yu; Wang, Nan-Mai

    2017-08-28

    This study investigated whether a self-designed assistive listening device (ALD) that incorporates an adaptive dynamic range optimization (ADRO) amplification strategy can surpass a commercially available monaurally worn linear ALD, SM100. Both subjective and objective measurements were implemented. Mandarin Hearing-In-Noise Test (MHINT) scores were the objective measurement, whereas participant satisfaction was the subjective measurement. The comparison was performed in a mixed design (i.e., subjects' hearing status being mild or moderate, quiet versus noisy, and linear versus ADRO scheme). The participants were two groups of hearing-impaired subjects, nine mild and eight moderate, respectively. The results of the ADRO system revealed a significant difference in the MHINT sentence reception threshold (SRT) in noisy environments between monaurally aided and unaided conditions, whereas the linear system did not. The benchmark results showed that the ADRO scheme is effectively beneficial to people who experience mild or moderate hearing loss in noisy environments. The satisfaction rating regarding overall speech quality indicated that the participants were satisfied with the speech quality of both ADRO and linear schemes in quiet environments, and they were more satisfied with ADRO than they with the linear scheme in noisy environments.

  13. Relief of knee flexion contracture and gait improvement following adaptive training for an assist device in a transtibial amputee: A case study.

    Science.gov (United States)

    Kim, Sol-Bi; Ko, Chang-Yong; Son, Jinho; Kang, Sungjae; Ryu, Jeicheong; Mun, Museong

    2017-01-01

    Management of a knee contracture is important for regaining gait ability in transtibial amputees. However, there has been little study of prosthesis training for enhancing mobility and improving range of motion in cases of restricted knee extension. This study aimed to evaluate the effects of adaptive training for an assist device (ATAD) for a transtibial amputee with a knee flexion contracture (KFC). A male transtibial amputee with KFC performed 4 months of ATAD with a multidisciplinary team. During the ATAD, the passive range of motion (PROM) in the knee, amputee mobility predictor (AMP) assessment, center of pressure (COP) on a force plate-equipped treadmill, gait features determined by three-dimensional motion analysis, and Short-Form 36 Item Health Survey (SF-36) scores were evaluated. Following ATAD, PROM showed immediate improvement (135.6 ± 2.4° at baseline, 142.5 ± 1.7° at Step 1, 152.1 ± 1.8° at Step 2, 165.8 ± 1.9° at Step 3, and 166.0 ± 1.4° at Step 4); this was followed by an enhanced COP. Gradually, gait features also improved. Additionally, the AMP score (5 at baseline to 29 at Step 4) and K-level (K0 at baseline to K3 at Step 4) increased after ATAD. Along with these improvements, the SF-36 score also improved. ATAD could be beneficial for transtibial amputees by relieving knee contractures and improving gait.

  14. Right ventricular longitudinal strain and right ventricular stroke work index in patients with severe heart failure: left ventricular assist device suitability for transplant candidates.

    Science.gov (United States)

    Cameli, M; Bernazzali, S; Lisi, M; Tsioulpas, C; Croccia, M G; Lisi, G; Maccherini, M; Mondillo, S

    2012-09-01

    Right ventricular (RV) systolic function has a critical role in determining the clinical outcome and the success of using left ventricular assist devices in patients with refractory heart failure. RV deformation analysis by speckle tracking echocardiography (STE) has recently allowed the analysis of RV longitudinal function. Using cardiac catheterization as the reference standard, this study aimed to explore the correlation between RV longitudinal function by STE and RV stroke work index (RVSWI) among patients referred for cardiac transplantation. Right heart catheterization and transthoracic echo-Doppler were simultaneously performed in 47 patients referred for cardiac transplant assessment due to refractory heart failure (ejection fraction 25.1 ± 4.5%). Thermodilution RV stroke volume and invasive pulmonary pressures were used to obtain RVSWI. RV longitudinal strain (RVLS) by STE was assessed averaging RV free-wall segments (free-wall RVLS). We also calculated. Tricuspid S' and tricuspid annular plane systolic excursion (TAPSE). No significant correlation was observed for TAPSE on tricuspid S' with RV stroke volume (r = 0.14 and r = 0.06, respectively). A close negative correlation between free-wall RVLS and RVSWI was found (r = -0.82; P rights reserved.

  15. Improved Approach With Subcostal Exchange of the HeartMate II Left Ventricular Assist Device: Difference in On and Off Pump?

    Science.gov (United States)

    Gaffey, Ann C; Chen, Carol W; Chung, Jennifer J; Phillips, Emily; Wald, Joyce; Williams, Matthew L; Low, David W; Acker, Michael A; Atluri, Pavan

    2017-11-01

    The HeartMate II (St. Jude Medical, Inc, St. Paul, MN [previously Thoratec]) left ventricular assist device (LVAD) exchange has traditionally involved a redo sternotomy. Alternate minimally invasive subcostal approaches have the advantage of avoiding sternal reentry, excessive bleeding, and prolonged recovery. This retrospective review included patients who underwent an exchange from May 2009 to March 2016. The patients were divided into three cohorts: (1) redo sternotomy, (2) subcostal approach involving cardiopulmonary bypass (CPB) (ON-CPB SC), and (3) subcostal approach off the CPB pump (OFF-CPB SC). Data pertaining to patients' baseline characteristics and outcomes were collected and analyzed. From May 1, 2009 to July 31, 2016, 33 HeartMate II LVAD exchanges were performed. There were 11 redo sternotomies and 22 subcostal exchanges, 12 of which were in the OFF-CPB SC group. There was no significant difference among the groups in terms of age (p = 0.75), sex (p = 0.95), and indication for exchange (p = 0.94). There was a higher red blood cell transfusion requirement within the sternotomy cohort (p rates were equivalent among the cohorts. Exchange of the HeartMate II LVAD can be accomplished with significantly improved recovery time and transfusion requirement through a less invasive subcostal approach when compared with sternotomy. The subcostal approach can be performed safely both on and off cardiopulmonary bypass. Copyright © 2017 The So