Sample records for assist device alvad

  1. Ventricular assist device (United States)

    VAD; RVAD; LVAD; BVAD; Right ventricular assist device; Left ventricular assist device; Biventricular assist device; Heart pump; Left ventricular assist system; LVAS; Implantable ventricular assist device

  2. Assistive Devices (United States)

    ... 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 dressed. Some are high-tech tools, such as computers. Others are much simpler, ...

  3. Ventricular Assist Device Support (United States)

    Fasseas, Panayotis; Kutalek, Steven P.; Samuels, Fania L.; Holmes, Elena C.; Samuels, Louis E.


    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias. (Tex Heart Inst J 2002;29:33–6) PMID:11995847

  4. Efficient adders for assistive devices

    Directory of Open Access Journals (Sweden)

    Mansi Jhamb


    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.

  5. Electrohydraulic ventricular assist device development. (United States)

    Diegel, P D; Mussivand, T; Holfert, J W; Juretich, J T; Miller, J A; Maclean, G K; Szurmak, Z; Santerre, J P; Rajagopalan, K; Dew, P A


    An electrohydraulic ventricular assist device has been developed. An axial flow pump driven by a brushless DC motor provides actuation. Energy is supplied by internal Ni/Cd batteries and by external Ag/Zn batteries, both rechargeable. Electromagnetic induction is used to pass energy through the skin with a transcutaneous energy transfer (TET) system. Physiologic control, battery management, motor commutation, and communication functions are performed by a surface mount internal controller. An infrared data link within the TET coils provides bidirectional communication between the external and internal controllers. A computer model was developed to predict system performance. The dimensions are 180 mm x 116 mm x 40 mm. An in vitro system pumped 5.7 L/min at 10 mmHg inflow and 100 mmHg outflow pressure. The internal battery can provide the projected energy requirements for 40 min after 540 charge/discharge cycles, and the external battery is capable of 4 hr of operation after 150 cycles. The TET system can deliver 60 W of power and exceeds 80% efficiency between 15 and 30 W. The device configuration is based on human cadaver and intraoperative fit trials. The device is being modified for calf implantation by redirecting the blood ports, increasing the output, and incorporating the internal controller in the unified device base.

  6. 21 CFR 870.3545 - Ventricular bypass (assist) device. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular bypass (assist) device. 870.3545... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that...

  7. Ventricular assist device in univentricular heart physiology. (United States)

    Brancaccio, Gianluca; Gandolfo, Fabrizio; Carotti, Adriano; Amodeo, Antonio


    The use of mechanical cardiac assistance is well established as a bridge to orthotopic heart transplantation (OHT) or to recovery for patients with congestive heart failure, however, the experience in single ventricle (SV) physiology is still limited. We report two cases of mechanical assistance in patients with SV physiology: a 2-year old male with hypoplastic left heart syndrome who underwent Norwood Stage I and II followed by HF and a 4-year old female with a univentricular heart who developed a severe right ventricular dysfunction 2 years after a cavopulmonary shunt. Mechanical support utilizing ventricular assist devices (VADs) is considered a valid tool to bridge patients with congestive heart failure to either OHT or to recovery. Increasing experience and improved outcomes utilizing this technology in children with biventricular hearts have led to considering employing these devices in failing SV treatment. We present 2 cases of terminally ill children with SV who were assisted with a VAD.

  8. Ventricular Assist Devices: Physiology Meets Technology (United States)


    vaslr resbane, and icrue systemic cir(nlatkm O(Mchet at aL. 1988). Non-ulsatile flow results in VADs 19 mico ulatory shiting snd edema formation...than 45 ininHg, and the oxygen saturation greater than 95 percent (Ley,, 1991). Hypoxeinia. initially may be due to pulmonary edema or a mild form of...1990). Combined Registry for the clinical use of mechanical ventricular assist devices: postcardiotomy cardiogenic shock. o36(1), 43-46. Mondejar, E

  9. 34 CFR 300.5 - Assistive technology device. (United States)


    ... 34 Education 2 2010-07-01 2010-07-01 false Assistive technology device. 300.5 Section 300.5... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.5 Assistive technology device. Assistive technology device means any item, piece of equipment, or product system, whether...

  10. Brain-controlled body movement assistance devices and methods

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  11. Brain-controlled body movement assistance devices and methods (United States)

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


    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.

  12. The medical physics of ventricular assist devices

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Houston G [Mechanical and Aerospace Engineering Department, Virginia Artificial Heart Institute, 122 Engineers Way, University of Virginia, Charlottesville, VA (United States); Throckmorton, Amy L [Biomedical Engineering Department, Virginia Artificial Heart Institute, University of Virginia, Charlottesville, VA (United States); Untaroiu, Alexandrina [Mechanical and Aerospace Engineering Department, Virginia Artificial Heart Institute, 122 Engineers Way, University of Virginia, Charlottesville, VA (United States); Song Xinwei [Mechanical and Aerospace Engineering Department, Virginia Artificial Heart Institute, 122 Engineers Way, University of Virginia, Charlottesville, VA (United States)


    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.

  13. The Flow Field Inside Ventricle Assist Device (United States)

    Einav, Shmuel; Rosenfeld, Moshe; Avrahami, Idit


    The evaluation of innovative ventricle assist devices (VAD), is of major importance. A New Left Heart Assist Device, with an improved energy converter unit, has been investigated both numerically and experimentally. For this purpose, an experimental Continuous Digital Particle Imagining Velocimetry (CDPIV) is combined with a computational fluid dynamics (CFD) analysis. These tools complement each other to result into a comprehensive description of the complex 3D, viscous and time-dependent flow field inside the artificial ventricle. A 3D numerical model was constructed to simulate the VAD pump and a time-depended CFD analysis with moving walls was performed to predict the flow behaviour in the VAD during the cardiac cycle. A commercial finite element package was used to solve the Navier-Stokes equations (FIDAP, Fluent Inc., Evanston). In the experimental analysis, an optically clear elastic model of the VAD was placed inside a 2D CDPIV system. The CDPIV system is capable of sampling 15 velocity vector fields per second based on image-pairs intervals lower than 0.5 millisecond. Continuous sequences of experimental images, followed by their calculated velocity transient fields, are given as animated presentation of the distensible VAD. These results are used for validating the CFD simulations. Once validated, the CFD results provide a detailed 3D and time dependent description of the flow field, allowing the identification of stagnation or high shear stress regions.

  14. The use of Computer Assisted Language Learning (CALL) Devices ...

    African Journals Online (AJOL)

    The use of Computer Assisted Language Learning (CALL) Devices in ... role of information and communication technologies in language learning and teaching. ... Classroom implications and applications for the effective Computer Assisted ...

  15. Endocarditis in left ventricular assist device (United States)

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


    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

  16. Percutaneous Ventricular Assist Devices: New Deus Ex Machina?

    Directory of Open Access Journals (Sweden)

    Diego Arroyo


    Full Text Available The development of ventricular assist devices has broadened the means with which one can treat acute heart failure. Percutaneous ventricular assist devices (pVAD have risen from recent technological advances. They are smaller, easier, and faster to implant, all important qualities in the setting of acute heart failure. The present paper briefly describes the functioning and assets of the most common devices used today. It gives an overview of the current evidence and indications for left ventricular assist device use in cardiogenic shock and high-risk percutaneous coronary intervention. Finally, extracorporeal life support devices are dealt with in the setting of hemodynamic support.

  17. Design of wheel-type walking-assist device

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  18. The cost of assistive devices for children with mobility limitation. (United States)

    Korpela, R A; Siirtola, T O; Koivikko, M J


    This study evaluated the costs of assistive devices for children with motor limitations at home, in day care, and in school, and the effect of diagnosis and severity of disabilities on costs. 201 children (mean age 7.4 years) who used 1274 various assistive devices (85.7% at home, 6.1% in day care, and 8.2% in school) were studied. The cost per device varied from $8.14 to $8138 with an average value of $539 per device. The distribution of costs per capita was unequal: 52.2% of children used 15.6% of total costs and 4.5% of children used 20.8% of total costs. The severity of motor impairment and the age of the child were the most important indicators associated with the need and cost of assistive devices. Assistive devices for basic needs, such as sitting, mobility, and personal hygiene, had a relatively low effect on costs in comparison with the high-technology devices, like powered wheelchairs and computers. Better cooperation with day care and school professionals, better assessment of needs, follow-up and recirculation of assistive devices are ways to promote rehabilitation services and partly solve the discrepancies between the costs of available technology and the resources to pay for it.

  19. Anaesthesia for patients undergoing ventricular assist-device implantation. (United States)

    Feussner, Markus; Mukherjee, Chirojit; Garbade, Jens; Ender, Joerg


    In the last 10 years, implantation of ventricular-assist devices has become an interesting option as either bridge-to-transplantation or destination procedure for patients with end-stage congestive heart failure. In the future, the number of ventricular assist device implantations is expected to increase furthermore. In general, this patient cohort is associated with significant co-morbidities, for example, pulmonary hypertension, peripheral vascular disease and renal insufficiency. Anaesthetic management for implantation of ventricular assist devices can be challenging for cardiac anaesthesiologists. Even minor changes in their haemodynamics and physiological parameters can cause significant morbidity and mortality. Experience in haemodynamic monitoring including echocardiography and pharmacological management (use of inotropes, phosphodiesterase inhibitors and vasopressors) is a requirement. Particularly, the diagnosis and therapy of right-sided heart failure after implantation of left-ventricular assist devices should be addressed.

  20. Ventricular Assist Device Support: for Management of Sustained Ventricular Arrhythmias



    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the s...

  1. Reference Device-Assisted Adaptive Location Fingerprinting

    Directory of Open Access Journals (Sweden)

    Dongjin Wu


    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.

  2. 47 CFR 74.870 - Wireless video assist devices. (United States)


    ... non-interference basis on VHF and UHF television channels to assist with production activities. (a... electronic news gathering purposes. (c) Wireless video assist devices may operate with a bandwidth not to exceed 6 MHz on frequencies in the bands 180-210 MHz (TV channels 8-12) and 470-698 MHz (TV channels...

  3. The diagnosis of left ventricular assist device thrombosis

    NARCIS (Netherlands)

    Gerds, H. Z. R.; Brugemann, J.; Rienstra, M.; Erasmus, M. E.


    The clinical course of a patient with a left ventricular assist device is described. A total of 6 weeks after device insertion, the lactate dehydrogenase (LDH) level increased to 2801 U/l despite adding low-molecular-weight heparin to acenocoumarol and aspirin. Pump thrombosis was suspected but unco

  4. Ventricular assist device support for management of sustained ventricular arrhythmias. (United States)

    Fasseas, Panayotis; Kutalek, Steven P; Samuels, Fania L; Holmes, Elena C; Samuels, Louis E


    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias.

  5. Fluid dynamics of heart assist device (United States)

    Jones, R. T.


    Certain hemodynamic phenomena that arise in connection with the use of artificial blood pumping devices are reviewed. Among these are: (1) Flows produced by collapsing bulbs; (2) the impedance presented by the aorta; (3) limiting velocities and instability of flow in elastic vessels; (4) effectiveness of valveless arterio-arterial pumps, and (5) wave reflection phenomena and instabilities associated with the intra-aortic balloon pump.

  6. Human Grasp Assist Device With Exoskeleton (United States)

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


    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.

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

    NARCIS (Netherlands)

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


    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 point

  8. Laparoscopic repair of diaphragmatic hernia after left ventricular assist device. (United States)

    Farma, Jeffrey; Leeser, David; Furukawa, Satoshi; Dempsey, Daniel T


    This case report describes a patient with a symptomatic diaphragmatic hernia that developed after orthotopic heart transplantation and explantation of a left ventricular assist device. The hernia was repaired laparoscopically, and at 6-month follow-up, she is without evidence of recurrence.

  9. Vocational Reintegration of Handicapped Workers with Assistive Devices (United States)

    Cooper, N. E.


    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…

  10. Roseomonas infection associated with a left ventricular assist device. (United States)

    Singal, Amit; Malani, Preeti N; Day, Larry J; Pagani, Francis D; Clark, Nina M


    Roseomonas species have been increasingly noted as causes of human infection. We present what we believe is the first case of left ventricular assist device (LVAD) infection secondary to Roseomonas. The clinical characteristics of Roseomonas infection and the pertinent features of LVAD infection are reviewed.

  11. [Fusarium pleural effusion after a ventricular assist device]. (United States)

    Villacorta, J; Blancard, A; Kerbaul, F; Guidon, C; Gouin, F


    We report the case of a 36-year-old man with a pleural effusion that complicates the postoperative period after the implantation of a ventricular assist device (VAD). The epidemiological, etiologic and therapeutic features of Fusarium infections were reviewed. Complete recovery of the infection was obtained after a treatment by liposomal amphotericine B (AmBisome) and 5 fluorocytosine.

  12. Patient-reported outcomes in left ventricular assist device therapy

    DEFF Research Database (Denmark)

    Brouwers, Corline; Denollet, Johan; de Jonge, Nicolaas;


    Technological advancements of left ventricular assist devices (LVAD) have created today's potential for extending the lives of patients with end-stage heart failure. Few studies have examined the effect of LVAD therapy on patient-reported outcomes (PROs), such as health status, quality of life...

  13. Implantation of left ventricular assist device complicated by undiagnosed thrombophilia. (United States)

    Szarszoi, Ondrej; Maly, Jiri; Turek, Daniel; Urban, Marian; Skalsky, Ivo; Riha, Hynek; Maluskova, Jana; Pirk, Jan; Netuka, Ivan


    A patient with dilated cardiomyopathy and no history of thromboembolic events received a surgically implanted axial-flow left ventricular assist device. After implantation, transesophageal echocardiography revealed a giant thrombus on the lateral and anterior aspects of the left ventricle. The inflow cannula inserted through the apex of the left ventricle was not obstructed, and the device generated satisfactory blood flow. Laboratory screening for thrombophilia showed protein S deficiency, heterozygous factor V Leiden mutation, and heterozygous MTHFR C667T mutation. During the entire duration of circulatory support, no significant suction events were detected, and the patient was listed for heart transplantation. Ventricular assist device implantation can unmask previously undiagnosed thrombophilia; therefore, it should be necessary to identify thrombophilic patients before cardiac support implantation.

  14. Left Ventricular Assist Devices: The Adolescence of a Disruptive Technology. (United States)

    Pinney, Sean P


    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.

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

    DEFF Research Database (Denmark)

    Pratas, Nuno; Popovski, Petar


    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......) 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...

  16. Peripartum cardiomyopathy, place of drug therapy, assist devices, and outcome after left ventricular assistance. (United States)

    Hamdan, Righab; Nassar, Pierre; Zein, Ali; Issa, Mohamad; Mansour, Hassan; Saab, Mohamad


    Peripartum cardiomyopathy remains a challenging obstetric and cardiologic emergency. We report 5 interesting cases of peripartum cardiomyopathy with different clinical courses, with 3 patients requiring left ventricular assist device implantation. One patient underwent pump explantation and aortic balloon valvuloplasty postsurgery. Two patients improved with the medical treatment alone without the need of assistance. We will review main important related issues. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Disseminated Streptococcus pneumoniae infection involving a ventricular assist device. (United States)

    Reeves, J S; Rajagopalan, N; Huaman, M A


    We describe the first reported case, to our knowledge, of disseminated pneumococcal infection involving a left ventricular assist device (LVAD). The management of this infection was extremely challenging, requiring multiple surgical debridements, LVAD removal, and prolonged courses of antibiotics. The Streptococcus pneumoniae isolate was found to be serotype 19F, which is included in both the pneumococcal polysaccharide and conjugate vaccines. This report highlights the importance of routine screening for up-to-date vaccination in patients who undergo LVAD implantation.

  18. Development and assessment of a hand assist device: GRIPIT. (United States)

    Kim, Byungchul; In, Hyunki; Lee, Dae-Young; Cho, Kyu-Jin


    Although various hand assist devices have been commercialized for people with paralysis, they are somewhat limited in terms of tool fixation and device attachment method. Hand exoskeleton robots allow users to grasp a wider range of tools but are heavy, complicated, and bulky owing to the presence of numerous actuators and controllers. The GRIPIT hand assist device overcomes the limitations of both conventional devices and exoskeleton robots by providing improved tool fixation and device attachment in a lightweight and compact device. GRIPIT has been designed to assist tripod grasp for people with spinal cord injury because this grasp posture is frequently used in school and offices for such activities as writing and grasping small objects. The main development objective of GRIPIT is to assist users to grasp tools with their own hand using a lightweight, compact assistive device that is manually operated via a single wire. GRIPIT consists of only a glove, a wire, and a small structure that maintains tendon tension to permit a stable grasp. The tendon routing points are designed to apply force to the thumb, index finger, and middle finger to form a tripod grasp. A tension-maintenance structure sustains the grasp posture with appropriate tension. Following device development, four people with spinal cord injury were recruited to verify the writing performance of GRIPIT compared to the performance of a conventional penholder and handwriting. Writing was chosen as the assessment task because it requires a tripod grasp, which is one of the main performance objectives of GRIPIT. New assessment, which includes six different writing tasks, was devised to measure writing ability from various viewpoints including both qualitative and quantitative methods, while most conventional assessments include only qualitative methods or simple time measuring assessments. Appearance, portability, difficulty of wearing, difficulty of grasping the subject, writing sensation, fatigability

  19. Modeling Users, Context and Devices for Ambient Assisted Living Environments (United States)

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


    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

  20. Hemodynamic Performance of a Novel Right Ventricular Assist Device (PERKAT) (United States)

    Schulze, P. Christian; Ferrari, Markus W.


    Acute right ventricular failure (RVF) is an increasing clinical problem and a life-threatening condition. Right ventricular assist devices represent a reasonable treatment option for patients with refractory RVF. We here present a novel percutaneously implantable device for right ventricular support. The PERKAT device is based on a nitinol stent cage, which is covered with valve-carrying foils. A flexible outlet trunk with a pigtail tip is connected to the distal part. The device is driven by an intra-aortic balloon pump (IABP) drive unit, which inflates/deflates a standard IABP-balloon placed within the stent cage. In-vitro evaluation was done in a liquid bath containing water or blood analog. The PERKAT device was tested in different afterload settings using two different IABP-balloons and varying inflation/deflation rates. We detected flow rates ranging from 1.97 to 3.93 L/min depending on the afterload setting, inflation/deflation rate, balloon size, and the medium used. Flow rates between water and blood analog were nearly comparable, and in the higher inflation/deflation rate settings slightly higher with water. Based on this promising in vitro data, the innovative percutaneously implantable PERKAT device has a potential to become a therapeutic option for patients with RVF refractory to medical treatment. PMID:27831998

  1. To ventricular assist devices or not: When is implantation of a ventricular assist device appropriate in advanced ambulatory heart failure? (United States)

    Cerier, Emily; Lampert, Brent C; Kilic, Arman; McDavid, Asia; Deo, Salil V; Kilic, Ahmet


    Advanced heart failure has been traditionally treated via either heart transplantation, continuous inotropes, consideration for hospice and more recently via left ventricular assist devices (LVAD). Heart transplantation has been limited by organ availability and the futility of other options has thrust LVAD therapy into the mainstream of therapy for end stage heart failure. Improvements in technology and survival combined with improvements in the quality of life have made LVADs a viable option for many patients suffering from heart failure. The question of when to implant these devices in those patients with advanced, yet still ambulatory heart failure remains a controversial topic. We discuss the current state of LVAD therapy and the risk vs benefit of these devices in the treatment of heart failure.

  2. Activity Recognition in Individuals Walking With Assistive Devices: The Benefits of Device-Specific Models. (United States)

    Lonini, Luca; Gupta, Aakash; Deems-Dluhy, Susan; Hoppe-Ludwig, Shenan; Kording, Konrad; Jayaraman, Arun


    Wearable sensors gather data that machine-learning models can convert into an identification of physical activities, a clinically relevant outcome measure. However, when individuals with disabilities upgrade to a new walking assistive device, their gait patterns can change, which could affect the accuracy of activity recognition. The objective of this study was to assess whether we need to train an activity recognition model with labeled data from activities performed with the new assistive device, rather than data from the original device or from healthy individuals. Data were collected from 11 healthy controls as well as from 11 age-matched individuals with disabilities who used a standard stance control knee-ankle-foot orthosis (KAFO), and then a computer-controlled adaptive KAFO (Ottobock C-Brace). All subjects performed a structured set of functional activities while wearing an accelerometer on their waist, and random forest classifiers were used as activity classification models. We examined both global models, which are trained on other subjects (healthy or disabled individuals), and personal models, which are trained and tested on the same subject. Median accuracies of global and personal models trained with data from the new KAFO were significantly higher (61% and 76%, respectively) than those of models that use data from the original KAFO (55% and 66%, respectively) (Wilcoxon signed-rank test, P=.006 and P=.01). These models also massively outperformed a global model trained on healthy subjects, which only achieved a median accuracy of 53%. Device-specific models conferred a major advantage for activity recognition. Our results suggest that when patients use a new assistive device, labeled data from activities performed with the specific device are needed for maximal precision activity recognition. Personal device-specific models yield the highest accuracy in such scenarios, whereas models trained on healthy individuals perform poorly and should not be

  3. The HeartSaver left ventricular assist device: an update. (United States)

    Hendry, P J; Mussivand, T V; Masters, R G; Bourke, M E; Guiraudon, G M; Holmes, K S; Day, K D; Keon, W J


    Ventricular assist devices have been shown to be effective as bridges to transplantation and recovery for patients with end-stage heart failure. Current technology has been limited because of the need for percutaneous connections with controllers. The HeartSaver ventricular assist device (VAD) (World Heart Corporation, Ottawa, Ontario, Canada) was developed with the intention of having a completely implantable, portable VAD system. The system consists of an electrohydraulic blood pump, internal and external battery power, and a transcutaneous energy transfer and telemetry unit that allows for power transmission through the skin. Control of the device may be achieved locally or remotely through a variety of communication systems. The device has been modified with the Series II preclinical version being available for in vitro (mock loop) and in vivo (bovine model) testing. Seventeen Series II devices have been functional on mock loops or other testing trials for an accumulated 900 days of operation. There have been eight acute experiments using a bovine model to test various components as they have become available from manufacturing. Mean pump output was 10.4 +/- 1.1 L/min in full-fill/full-eject mode. Changes in the last 24 months include (1) cannula redesign for better port alignment and integration of tissue valves; (2) battery redesign to convert to new lithium-ion cells; (3) optimized infrared information and electromagnetic inductance energy transmission through various skin thicknesses and pigmentation; and (4) improved reliability of internal and external controller hardware and software. Modifications have been required to optimize the HeartSaver VAD's performance. The final HeartSaver VAD design will be produced in the near future to allow for formal in vitro and in vivo testing before clinical implantation.

  4. Postoperative care and complications after ventricular assist device implantation. (United States)

    Allen, Sara Jane; Sidebotham, David


    In this article, the routine postoperative care and complications of patients with ventricular assist devices are reviewed. Routine postoperative care encompasses patients who have undergone emergency ventricular assist device (VAD) implantation for acute cardiogenic shock, as a bridge to decision making, and semi-elective patients who have undergone VAD implantation for end-stage heart failure, either as destination therapy or as a bridge to heart transplantation. Early postoperative management should focus on haemodynamic optimisation, including fluid and inotrope therapy, VAD settings and support of right ventricular function. Echocardiography is an essential tool in optimising haemodynamics and identifying complications. Early postoperative complications include bleeding, arrhythmias, right ventricular failure and infection. Late postoperative problems include bleeding, thrombosis and thrombo-embolism, device failure and psychological problems. In a small percentage of patients, weaning and explantation of the VAD are possible. For patients undergoing VAD implantation for destination therapy, end-of-life care planning should form part of the multidisciplinary care of the patient.

  5. Mobilizing Knowledge: The Evidence Gap for Assistive Devices

    Directory of Open Access Journals (Sweden)

    Edward D. Lemaire


    Full Text Available Knowledge mobilization can be hindered in healthcare technology settings where the pace of change outpaces the ability to perform high-quality research methodologies that provide timely knowledge to enable informed prescription and technology application to the end user. Although well-controlled research with appropriate sample sizes is needed, this approach must be balanced with other evidence sources to address the knowledge immediacy requirements. Using carbon-fibre ankle–foot orthoses (i.e., lower-limb braces that improve stability, alignment, and foot-to-ground placement as a case study, various sources of assistive device evidence were explored for their contribution to the continuum of knowledge in this area. A basic level of knowledge exists, but the quality is insufficient to inform the physical rehabilitation community on selecting from the almost 70 different devices on the market and the expected clinical outcomes for a target population. A combination of enhanced single-participant reports should be considered as an important part of the knowledge continuum and essential for knowledge immediacy. This approach must also be expanded to national and multinational database initiatives that provide a better base from which to extract knowledge on assistive device performance and mobilize this knowledge to provide optimal care for people with physical disabilities.

  6. Current Trends in Implantable Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Jens Garbade


    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.

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

    DEFF Research Database (Denmark)

    Boissy, Patrice; Hester, Todd; Sherrill, Delsey


    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...... and abandoned. Ecologically sound, evidence based outcome measures need to be developed so as to capture the inherent complexities behind real life use of MAD and identify markers and mitigators of a successful integration of MAD into the daily activities of stroke survivors. In this study, we used...

  8. FOLFOX Induced Takotsubo Cardiomyopathy Treated with Impella Assist Device

    Directory of Open Access Journals (Sweden)

    Swethika Sundaravel


    Full Text Available Chemotherapy induced cardiotoxicity is becoming increasingly prevalent with several new agents being used recently. The incidence of Takotsubo cardiomyopathy due to 5-fluorouracil based chemotherapeutic regimens like FOLFOX is not uncommon. It is also seen with platinum based chemotherapy. Most of these patients have reversible cardiotoxicity and the cardiac function recovers within a short period with supportive treatment. Here we have a patient who presented with cardiogenic shock after 5 days of receiving FOLFOX regimen for colorectal adenocarcinoma. She was treated with a percutaneous left ventricular assist device, Impella CP, for hemodynamic support with excellent outcome.

  9. Subacute gastric perforation caused by a left ventricular assist device

    Institute of Scientific and Technical Information of China (English)

    Demetris Yannopoulos


    This case report describes a rare complication of a left ventricular assist device (LVAD). A patient with ischemic cardiomyopathy had an LVAD placed due to intractable congestive heart failure following a large anterior myocardial infarction. The patient developed chronic bacteremia and multiple septic episodes. A gastric endoscopy revealed perforation of the anterior wall of the stomach by the LVAD. Gastric acid related erosions were present on the metallic surface suggesting prolonged exposure. This is the second case report of this rare complication and the first case report of a subacute course.

  10. [Development of Special Drive Pediatric Ventricular Assist Device]. (United States)

    Wang, Wei; Zhu, Jianming; Wang, Binjun; Zhang, Qianqing


    This paper uses AVR16 SCM, programming to achieve the software of PWM (pulse width modulation) control of intelligent H bridge chip LMD18200 driver of high speed DC motor, makes special speed tablet, obtains speed signal of high speed for photocoupler PC817, through the A/D conversion and processing circuit, and realizes the LED LCD digital display speed scheme. The driver for the pediatric ventricular assist device has been used at the laboratory trial, has high performance and wide application prospect.

  11. Interjoint coordination and the personal lift-assist device. (United States)

    Graham, Ryan B; Smallman, Catherine L W; Sadler, Erin M; Stevenson, Joan M


    It has been suggested that interjoint coordination may serve to reduce joint stress and muscular demand and to maintain balance during dynamic lifting tasks, thus having implications for safe lifting practices. Before recommending the use of an on-body ergonomic aid, the Personal Lift-Assist Device (PLAD), it is important to determine any effects this device may have on interjoint coordination. Principal component analyses were applied to relative phase angle waveforms, defining the hip-knee and lumbar spine-hip coordination of 15 males and 15 females during a repetitive lifting task. When wearing the PLAD, users lifted with more synchronous hip-knee and lumbar spine-hip coordination patterns (P lift (P < .01) for all conditions. No significant main effects of sex or significant interactions were observed on any of the outcome variables.

  12. Anatomic considerations for abdominally placed permanent left ventricular assist devices. (United States)

    Parnis, S M; McGee, M G; Igo, S R; Dasse, K; Frazier, O H


    To determine anatomic parameters for a permanent, electrically actuated left ventricular assist device (LVAD), the effects of abdominal placement of pneumatic LVADs used as temporary support for patients awaiting heart transplantation was studied. Understanding the anatomic constraints imposed by the abdominal viscera in LVAD placement is crucial, because improper placement can result in compression or obstruction of adjacent structures. Anatomic compatibility was assessed in four men (age 22-48 years) who were supported by the LVAD for over 1 month (range 35-132 days). The pump was intraperitoneally placed in the left upper quadrant. Radiographic techniques were employed, including CT scanning (with patients supine) and contrast imaging (patients in anatomical position), and the pump and conduits appeared to be properly positioned, with minimal compression of the body of the stomach, and no obstruction of adjacent organs. Three patients returned to a solid food diet and exercised daily by stationary cycling and walking. No signs of migration or erosion of the pump were present at the time of LVAD removal and cardiac transplantation. Successful clinical experience with short-term use of the LVAD suggests that the electrically actuated device can be well tolerated in patients requiring permanent left ventricular assistance.

  13. Fiber Bragg grating sensor-based communication assistance device (United States)

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


    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.

  14. Fluid Structure Interaction Simulations of Pediatric Ventricular Assist Device Operation (United States)

    Long, Chris; Marsden, Alison; Bazilevs, Yuri


    Pediatric ventricular assist devices (PVADs) are used for mechanical circulatory support in children with failing hearts. They can be used to allow the heart to heal naturally or to extend the life of the patient until transplant. A PVAD has two chambers, blood and air, separated by a flexible membrane. The air chamber is pressurized, which drives the membrane and pumps the blood. The primary risk associated with these devices is stroke or embolism from thrombogenesis. Simulation of these devices is difficult due to a complex coupling of two fluid domains and a thin membrane, requiring fluid-structure interaction modeling. The goal of this work is to accurately simulate the hemodynamics of a PVAD. We perform FSI simulations using an Arbitrary Lagrangian-Eulerian (ALE) finite element framework to account for large motions of the membrane and the fluid domains. The air, blood, and membrane are meshed as distinct subdomains, and a method for non-matched discretizations at the fluid-structure interface is presented. The use of isogeometric analysis to model the membrane mechanics is also discussed, and the results of simulations are presented.

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

    Directory of Open Access Journals (Sweden)

    Luigi Brancato


    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.

  16. Medical devices; obstetrical and gynecological devices; classification of the assisted reproduction embryo image assessment system. Final order. (United States)


    The Food and Drug Administration (FDA) is classifying the Assisted Reproduction Embryo Image Assessment System into class II (special controls). The special controls that will apply to the device are identified in this order, and will be part of the codified language for the Assisted Reproduction Embryo Image Assessment System classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  17. Memory-assisted measurement-device-independent quantum key distribution (United States)

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


    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.

  18. Grasp Assist Device with Shared Tendon Actuator Assembly (United States)

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


    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.

  19. Self-assessment of classroom assistive listening devices. (United States)

    Odelius, Johan; Johansson, Orjan


    Self-assessment of classroom assistive listening devices (ALDs) based on induction loop systems was carried out in Swedish classes for hearing-impaired students. A questionnaire was developed and completed by 25 students (bilateral hearing aid users, 10-20 years old). Responses for hearing aid microphone mode (M) and telecoil mode (T) were collected. Two attributes, audibility and awareness, were identified and assigned to either mode. Better audibility was achieved in T-mode. Students with severe hearing loss benefited more using T-mode when compared to the better hearing students, especially in more difficult listening situations. Better awareness was achieved in M-mode; students could better hear, locate and segregate sounds in the environment around them. Depending on the situation, students make different choices between audibility and awareness. Self-assessment is a promising approach for determining what combination of ALD design and function that will best benefit the students.

  20. Renal failure in patients with left ventricular assist devices. (United States)

    Patel, Ami M; Adeseun, Gbemisola A; Ahmed, Irfan; Mitter, Nanhi; Rame, J Eduardo; Rudnick, Michael R


    Implantable left ventricular assist devices (LVADs) are increasingly being used as a bridge to transplantation or as destination therapy in patients with end stage heart failure refractory to conventional medical therapy. A significant number of these patients have associated renal dysfunction before LVAD implantation, which may improve after LVAD placement due to enhanced perfusion. Other patients develop AKI after implantation. LVAD recipients who develop AKI requiring renal replacement therapy in the hospital or who ultimately require long-term outpatient hemodialysis therapy present management challenges with respect to hemodynamics, volume, and dialysis access. This review discusses the mechanics of a continuous-flow LVAD (the HeartMate II), the effects of continuous blood flow on the kidney, renal outcomes of patients after LVAD implantation, dialysis modality selection, vascular access, hemodynamic monitoring during the dialytic procedure, and other issues relevant to caring for these patients.

  1. Compassionate deactivation of ventricular assist devices in pediatric patients. (United States)

    Hollander, Seth A; Axelrod, David M; Bernstein, Daniel; Cohen, Harvey J; Sourkes, Barbara; Reddy, Sushma; Magnus, David; Rosenthal, David N; Kaufman, Beth D


    Despite greatly improved survival in pediatric patients with end-stage heart failure through the use of ventricular assist devices (VADs), heart failure ultimately remains a life-threatening disease with a significant symptom burden. With increased demand for donor organs, liberalizing the boundaries of case complexity, and the introduction of destination therapy in children, more children can be expected to die while on mechanical support. Despite this trend, guidelines on the ethical and pragmatic issues of compassionate deactivation of VAD support in children are strikingly absent. As VAD support for pediatric patients increases in frequency, the pediatric heart failure and palliative care communities must work toward establishing guidelines to clarify the complex issues surrounding compassionate deactivation. Patient, family and clinician attitudes must be ascertained and education regarding the psychological, legal and ethical issues should be provided. Furthermore, pediatric-specific planning documents for use before VAD implantation as well as deactivation checklists should be developed to assist with decision-making at critical points during the illness trajectory. Herein we review the relevant literature regarding compassionate deactivation with a specific focus on issues related to children.

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

    Directory of Open Access Journals (Sweden)

    Hiriyur Shivalingappa Jayanthkumar


    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.

  3. Development of an interprofessional pediatric ventricular assist device support team. (United States)

    Furness, Sarah; Hyslop-St George, Cecilia; Pound, Barbara; Earle, Misty; Maurich, Andrea; Rice, Danika; Humpl, Tilman


    Caring for pediatric patients with a ventricular assist device (VAD) requires a collaborative approach from an interprofessional team to ensure maximum patient safety and optimal outcomes. Initiating a VAD program is challenging, due to the complex medical and technical nature of this device and associated learning needs. At our institution, the development of the interprofessional VAD support team was established in four phases. Initial Education, Core Team Formation, Expansion, and Evaluation. A "core VAD team" was created after the initial education at an established VAD center. In a third step, all efforts were directed toward increasing the number of health care professionals caring for the VAD patients in the Cardiac Critical Care setting and on the Cardiac ward. The last phase consists of ongoing evaluation. Several key areas imperative to the care of a patient on a VAD were identified and further elaborated. The complex care of a patient on a VAD needs a specialized team approach to cover all patient care needs. Ongoing interprofessional education continues to improve competency of care. Continuity of care was assured on all levels of service to ensure the best possible outcomes.

  4. Changes in Spirometry After Left Ventricular Assist Device Implantation. (United States)

    Mohamedali, Burhan; Bhat, Geetha; Yost, Gardner; Tatooles, Antone


    Left ventricular assist devices (LVADs) are increasingly being used as life-saving therapy in patients with end-stage heart failure. The changes in spirometry following LVAD implantation and subsequent unloading of the left ventricle and pulmonary circulation are unknown. In this study, we explored long-term changes in spirometry after LVAD placement. In this retrospective study, we compared baseline preoperative pulmonary function test (PFT) results to post-LVAD spirometric measurements. Our results indicated that pulmonary function tests were significantly reduced after LVAD placement (forced expiratory volume in one second [FEV1 ]: 1.9 vs.1.7, P = 0.016; forced vital capacity [FVC]: 2.61 vs. 2.38, P = 0.03; diffusing capacity of the lungs for carbon monoxide [DLCO]: 14.75 vs. 11.01, P = 0.01). Subgroup analysis revealed greater impairment in lung function in patients receiving HeartMate II (Thoratec, Pleasanton, CA, USA) LVADs compared with those receiving HeartWare (HeartWare, Framingham, MA, USA) devices. These unexpected findings may result from restriction of left anterior hemi-diaphragm; however, further prospective studies to validate our findings are warranted.

  5. Effects of an Elastic Hamstring Assistance Device During Downhill Running

    Directory of Open Access Journals (Sweden)

    Aldret Randy L


    Full Text Available The purpose of this study was to determine the appropriateness of using an elastic hamstring assistance device to reduce perceived levels of soreness, increase isometric strength, increase passive range of motion, and decrease biomarkers of muscle damage after eccentric exercise, specifically, downhill running This study was conducted in a university exercise physiology laboratory placing sixteen apparently healthy males (X = 21.6 ± 2.5 years into two groups using a pre-test/post-test design. Pre-intervention measures taken included participants’ body height, body mass, body fat, capillary blood samples, VO2max, isometric hamstring strength at 45 and 90 degrees of flexion and passive hamstring range of motion. Post-intervention measures included blood biomarkers, passive range of motion, the perceived level of soreness and isometric strength. An analysis of normality of data was initially conducted followed by multivariate analysis of variance (MANOVA of hamstring strength at 45 and 90 degrees of flexion, blood myoglobin and passive range of motion of the hamstrings. Statistically significant changes were noted in subject-perceived muscle soreness and isometric strength at 90 degrees at the 24-hour post-exercise trial measure between the two groups. Results would suggest the findings could be explained by the decrease in muscle soreness from utilizing the device during the exercise trial. Further research should be conducted to address sample size issues and to determine if the results are comparable on different surfaces.

  6. Effects of an Elastic Hamstring Assistance Device During Downhill Running. (United States)

    Aldret, Randy L; Trahan, Brittany A; Davis, Greggory; Campbell, Brian; Bellar, David M


    The purpose of this study was to determine the appropriateness of using an elastic hamstring assistance device to reduce perceived levels of soreness, increase isometric strength, increase passive range of motion, and decrease biomarkers of muscle damage after eccentric exercise, specifically, downhill running This study was conducted in a university exercise physiology laboratory placing sixteen apparently healthy males (X = 21.6 ± 2.5 years) into two groups using a pre-test/post-test design. Pre-intervention measures taken included participants' body height, body mass, body fat, capillary blood samples, VO2max, isometric hamstring strength at 45 and 90 degrees of flexion and passive hamstring range of motion. Post-intervention measures included blood biomarkers, passive range of motion, the perceived level of soreness and isometric strength. An analysis of normality of data was initially conducted followed by multivariate analysis of variance (MANOVA) of hamstring strength at 45 and 90 degrees of flexion, blood myoglobin and passive range of motion of the hamstrings. Statistically significant changes were noted in subject-perceived muscle soreness and isometric strength at 90 degrees at the 24-hour post-exercise trial measure between the two groups. Results would suggest the findings could be explained by the decrease in muscle soreness from utilizing the device during the exercise trial. Further research should be conducted to address sample size issues and to determine if the results are comparable on different surfaces.

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

    DEFF Research Database (Denmark)

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


    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......Many stroke patients are prescribed canes or other mobility assistive devices. Once taken home, these mobility assistive devices are often abandoned or misused. A means for assessing the use of the cane in the home and community settings is required to assist clinicians in the prescription...

  8. Left ventricular assist device-related infection: treatment and outcome. (United States)

    Simon, David; Fischer, Staci; Grossman, Angela; Downer, Carol; Hota, Bala; Heroux, Alain; Trenholme, Gordon


    Left ventricular assist device (LVAD) implantation has become an effective treatment option for patients with severe heart failure awaiting transplantation. Significant infection rates have been reported among LVAD recipients. However, few reports have focused specifically on device infection, its treatment, and the impact of LVAD-related infection on clinical outcome. Forty-six LVAD-related infections were diagnosed in 38 (50%) of 76 patients who underwent LVAD implantation as a bridge to transplantation. Twenty-nine episodes of LVAD-related bloodstream infection (BSI) (including 5 that were cases of LVAD endocarditis) and 17 episodes of local LVAD infection were identified. Diabetes mellitus appeared to increase the risk of BSI among patients with LVAD infection. LVAD-related infection delayed transplantation, as reflected by longer device-support times (a mean duration +/- SEM of 182.8+/-31.1 days, compared with 66.3+/-8.8 days; P

  9. Implantation of a left ventricular assist device in patients with a complex apical anatomy. (United States)

    Palmen, Meindert; Verwey, Harriette F; Haeck, Marlieke L A; Holman, Eduard R; Schalij, Martin J; Klautz, Robert J M


    Implantation of a left ventricular assist device can be challenging in patients with an altered apical anatomy after cardiac surgery or as the result of the presence of a calcified apical aneurysm. In this paper we present 2 cases with a challenging apical anatomy and introduce a new surgical technique facilitating left ventricular assist device implantation in these patients.

  10. An unknown complication of peripherally inserted central venous catheter in a patient with ventricular assist device

    Directory of Open Access Journals (Sweden)

    Parikh M


    Full Text Available We report an unknown complication of peripherally inserted central venous catheter in a patient with Ventricular Assist Device. This rare complication led to the failure of the right ventricular assist device, which could be detrimental in patients with dilated cardiomyopathy.

  11. 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


    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 teste

  12. 38 CFR 17.152 - Devices to assist in overcoming the handicap of deafness. (United States)


    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Devices to assist in overcoming the handicap of deafness. 17.152 Section 17.152 Pensions, Bonuses, and Veterans' Relief DEPARTMENT... in overcoming the handicap of deafness. Devices for assisting in overcoming the handicap of...


    NARCIS (Netherlands)



    Helmholtz Ventricular Assist Devices (VAD) are pneumatically driven polyurethane membrane pumps with various volumes. The pumps are placed paracorporeally and connected with commercially available cannulas between the left atrium and aorta (left ventricular assist device) and/or right atrium and pul

  14. Magnetic design for the PediaFlow ventricular assist device. (United States)

    Noh, Myounggyu D; Antaki, James F; Ricci, Michael; Gardiner, Jeff; Paden, Dave; Wu, Jingchun; Prem, Ed; Borovetz, Harvey; Paden, Bradley E


    This article describes a design process for a new pediatric ventricular assist device, the PediaFlow. The pump is embodied in a magnetically levitated turbodynamic design that was developed explicitly based on the requirements for chronic support of infants and small children. The procedure entailed the consideration of multiple pump topologies, from which an axial mixed-flow configuration was chosen for further development. The magnetic design includes permanent-magnet (PM) passive bearings for radial support of the rotor, an actively controlled thrust actuator for axial support, and a brushless direct current (DC) motor for rotation. These components are closely coupled both geometrically and magnetically, and were therefore optimized in parallel, using electromagnetic, rotordynamic models and fluid models, and in consideration of hydrodynamic requirements. Multiple design objectives were considered, including efficiency, size, and margin between critical speeds to operating speed. The former depends upon the radial and yaw stiffnesses of the PM bearings. Analytical expressions for the stiffnesses were derived and verified through finite element analysis (FEA). A toroidally wound motor was designed for high efficiency and minimal additional negative radial stiffness. The design process relies heavily on optimization at the component level and system level. The results of this preliminary design optimization yielded a pump design with an overall stability margin of 15%, based on a pressure rise of 100 mm Hg at 0.5 lpm running at 16,000 rpm.

  15. The effect of atmospheric pressure on ventricular assist device output. (United States)

    Goto, Takeshi; Sato, Masaharu; Yamazaki, Akio; Fukuda, Wakako; Watanabe, Ken-Ichi; Daitoku, Kazuyuki; Minakawa, Masahito; Fukui, Kozo; Suzuki, Yasuyuki; Fukuda, Ikuo


    The effect of cabin pressure change on the respiratory system during flight is well documented in the literature, but how the change in atmospheric pressure affects ventricular assist device (VAD) output flow has not been studied yet. The purpose of our study was to evaluate the change in VAD output using a mock circulatory system in a low-pressure chamber mimicking high altitude. Changes in output and driving pressure were measured during decompression from 1.0 to 0.7 atm and pressurization from 0.7 to 1.0 atm. Two driving systems were evaluated: the VCT system and the Mobart system. In the VCT system, output and driving pressure remained the same during decompression and pressurization. In the Mobart system, the output decreased as the atmospheric pressure dropped and recovered during pressurization. The lowest output was observed at 0.7 atm, which was 80% of the baseline driven by the Mobart system. Under a practical cabin pressure of 0.8 atm, the output driven by the Mobart system was 90% of the baseline. In the Mobart system, the output decreased as the atmospheric pressure dropped, and recovered during pressurization. However, the decrease in output was slight. In an environment where the atmospheric pressure changes, it is necessary to monitor the diaphragmatic motion of the blood pump and the driving air pressure, and to adjust the systolic:diastolic ratio as well as the positive and negative pressures in a VAD system.

  16. Portable pneumatic biventricular driver for the Thoratec ventricular assist device. (United States)

    Farrar, D J; Buck, K E; Coulter, J H; Kupa, E J


    As patients with left ventricular (LVAD) and biventricular assist devices are supported for increasingly long durations while awaiting heart transplantation or cardiac recovery, there is a need to facilitate greater patient mobility and ambulation. To meet these needs, the authors have developed the Thoratec TLC-II Portable VAD Driver, which is a small brief-case sized (33 x 34 x 13 cm) pneumatic unit for Thoratec's paracorporeal and implantable VADs. The TLC-II consists of an electric motor driven air compressor for supplying both positive and negative air pressure, solenoid valves for switching between LVAD/RVAD filling and ejection, and microcontroller based electronics and firmware. Four power sources are provided: external power, two rechargeable lithium-ion battery packs, and an emergency battery that drives an independent electronic back-up system. The 8 kg TLC-II can be carried by hand, with a shoulder strap, or pushed on a wheeled mobility cart. Trend information stored in the TLC-II can be accessed by an external system computer with a color touchscreen mounted on a docking station, which also houses the battery charger. Control configurations (univentricular/biventricular operation, beat rates, etc.) are entered on the touchscreen and programmed into the TLC-II. In vitro testing demonstrates the ability to pump VAD outputs up to 7 L/min. By providing improved patient mobility, this small driver will enhance rehabilitation and improve the quality of life of VAD patients.

  17. Frank-starling control of a left ventricular assist device. (United States)

    Stevens, Michael Charles; Gaddum, Nicholas Richard; Pearcy, Mark; Salamonsen, Robert F; Timms, Daniel Lee; Mason, David Glen; Fraser, John F


    A physiological control system was developed for a rotary left ventricular assist device (LVAD) in which the target pump flow rate (LVADQ) was set as a function of left atrial pressure (LAP), mimicking the Frank-Starling mechanism. The control strategy was implemented using linear PID control and was evaluated in a pulsatile mock circulation loop using a prototyped centrifugal pump by varying pulmonary vascular resistance to alter venous return. The control strategy automatically varied pump speed (2460 to 1740 to 2700 RPM) in response to a decrease and subsequent increase in venous return. In contrast, a fixed-speed pump caused a simulated ventricular suction event during low venous return and higher ventricular volumes during high venous return. The preload sensitivity was increased from 0.011 L/min/mmHg in fixed speed mode to 0.47L/min/mmHg, a value similar to that of the native healthy heart. The sensitivity varied automatically to maintain the LAP and LVADQ within a predefined zone. This control strategy requires the implantation of a pressure sensor in the left atrium and a flow sensor around the outflow cannula of the LVAD. However, appropriate pressure sensor technology is not yet commercially available and so an alternative measure of preload such as pulsatility of pump signals should be investigated.

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

    Directory of Open Access Journals (Sweden)

    Rady Mohamed Y


    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

  19. Pruning a decision tree for selecting computer-related assistive devices for people with disabilities. (United States)

    Chi, Chia-Fen; Tseng, Li-Kai; Jang, Yuh


    Many disabled individuals lack extensive knowledge about assistive technology, which could help them use computers. In 1997, Denis Anson developed a decision tree of 49 evaluative questions designed to evaluate the functional capabilities of the disabled user and choose an appropriate combination of assistive devices, from a selection of 26, that enable the individual to use a computer. In general, occupational therapists guide the disabled users through this process. They often have to go over repetitive questions in order to find an appropriate device. A disabled user may require an alphanumeric entry device, a pointing device, an output device, a performance enhancement device, or some combination of these. Therefore, the current research eliminates redundant questions and divides Anson's decision tree into multiple independent subtrees to meet the actual demand of computer users with disabilities. The modified decision tree was tested by six disabled users to prove it can determine a complete set of assistive devices with a smaller number of evaluative questions. The means to insert new categories of computer-related assistive devices was included to ensure the decision tree can be expanded and updated. The current decision tree can help the disabled users and assistive technology practitioners to find appropriate computer-related assistive devices that meet with clients' individual needs in an efficient manner.

  20. Device-Related Thrombosis in Continuous-Flow Left Ventricular Assist Device Support. (United States)

    Doligalski, Christina Teeter; Jennings, Douglas L


    Advanced heart failure therapy has been revolutionized with the advent of continuous-flow ventricular assist devices (CF-LVADs) which have improved both survival and quality of life. Despite this, support with CF-LVADs is frequently complicated, with 70% of recipients experiencing a major complication in the first year of durable support. The most concerning of these complications to emerge is device-related thrombosis, which is associated with increased morbidity and mortality. Pathophysiology and diagnosis are multifaceted and complex, with pump-specific and patient-specific factors to be considered. Incidence estimates are evolving with increases seen in the past 2 years compared with earlier implant data. Evidence for treatment is limited to case series and reports, which are subject to significant publication bias. Finally, appropriate primary and secondary prophylaxis is imprecise with multiple antiplatelet and antithrombotic strategies described. This review seeks to summarize the current literature surrounding the pathophysiology, diagnosis, and management of thrombosis in CF-LVAD recipients.

  1. Considering Material Culture in Assessing Assistive Devices: “Breaking up the Rhythm”

    Directory of Open Access Journals (Sweden)

    Sharon Anderson


    Full Text Available This paper reports on a project that looked at the meaning stroke survivors assigned to assistive devices. Material culture theory served as a framework to help stroke survivors explicitly consider [dis]ability as a discursive object with a socially constructed meaning that influenced how they thought about themselves with impairment. Material culture theory informed the design (taking and talking to their peers about photos of anything that assisted and analysis of the meaning of the assistive devices project. In our analysis of the narratives, survivors assigned three types of meanings to the assistive devices: markers of progress, symbolic objects of disability, and the possibility of independent participation. Notably, the meaning of assistive devices as progress, [dis]ability, and [poss]ability was equally evident as participants talked about mobility, everyday activities, and services. We discuss how considering [dis]ability as a discursive object in the situation might have enabled stroke survivors to participate.

  2. Simulating Ideal Assistive Devices to Reduce the Metabolic Cost of Running (United States)

    Uchida, Thomas K.; Seth, Ajay; Pouya, Soha; Dembia, Christopher L.; Hicks, Jennifer L.; Delp, Scott L.


    Tools have been used for millions of years to augment the capabilities of the human body, allowing us to accomplish tasks that would otherwise be difficult or impossible. Powered exoskeletons and other assistive devices are sophisticated modern tools that have restored bipedal locomotion in individuals with paraplegia and have endowed unimpaired individuals with superhuman strength. Despite these successes, designing assistive devices that reduce energy consumption during running remains a substantial challenge, in part because these devices disrupt the dynamics of a complex, finely tuned biological system. Furthermore, designers have hitherto relied primarily on experiments, which cannot report muscle-level energy consumption and are fraught with practical challenges. In this study, we use OpenSim to generate muscle-driven simulations of 10 human subjects running at 2 and 5 m/s. We then add ideal, massless assistive devices to our simulations and examine the predicted changes in muscle recruitment patterns and metabolic power consumption. Our simulations suggest that an assistive device should not necessarily apply the net joint moment generated by muscles during unassisted running, and an assistive device can reduce the activity of muscles that do not cross the assisted joint. Our results corroborate and suggest biomechanical explanations for similar effects observed by experimentalists, and can be used to form hypotheses for future experimental studies. The models, simulations, and software used in this study are freely available at and can provide insight into assistive device design that complements experimental approaches. PMID:27656901

  3. Institutional Cost Comparison Between Heart Transplants and Left Ventricular Assist Device Implantations. (United States)

    Chimanji, Neeraj; Kilic, Arman; Hasan, Ayesha; Higgins, Robert S D; Whitson, Bryan A; Kilic, Ahmet


    Increased numbers of end-stage heart failure patients and improved technology have led to increased use of left ventricular assist devices as a viable alternative to heart transplants. Given the current economic climate, we compared costs of heart transplant versus device placement. Medical records of patients who received heart transplants or left ventricular assist devices were cross-referenced with institutional financial data. The device cohort was limited to those receiving durable (not temporary) devices. Index admission, 1-year readmission, and overall 1-year charges were compared using standard statistical methods. Of 184 identified patients with end-stage heart failure surgical therapy, 121 received left ventricular assist devices, 43 had heart transplants, and 20 received left ventricular assist devices as bridge to heart transplant; these latter patients were excluded from our analyses. At index admission, mean charges were $863 433 ± $398 427 for device patients and $725 877 ± $488 685 for transplant patients (P = .05). One-year mean readmission rates were similar (4.65/transplant patient and 4.53/device patient; P = .94), with corresponding 1-year survival rates of 87.8% and 78.0% (P = .04). Total readmission charges during year 1 were $169 732 ± $242 366 for device patients and $201 682 ± $297 565 for transplant patients (P = .08), with corresponding overall charges at 1 year of $1 029 732 ± $450 498 and $927 559 ± $562 404 (P = .49). During the first year, heart transplant and left ventricular assist device placement have similar costs. Initial index admission costs seem to favor heart transplant, with device pump costs accounting for some of the difference. From a 1-year survival perspective, heart transplant may be more effective; however, with lack of suitable donors, left ventricular assist devices are valuable in the armamentarium of advanced heart failure surgical options.

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

    Directory of Open Access Journals (Sweden)

    Yu. V. Bogdanova


    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

  5. Past and present of cardiocirculatory assist devices: a comprehensive critical review

    Institute of Scientific and Technical Information of China (English)

    Gianluca Rigatelli; Francesco Santini; Giuseppe Faggian


    During the last 20 years, the management of heart failure has significantly improved by means of new pharmacotherapies, more timely invasive treatments and device assisted therapies. Indeed, advances in mechanical support, namely with the development of more efficient left ventricular assist devices (LVADs), and the total artificial heart have reduced mortality and morbidity in patients awaiting transplantation, so much so, that LVADs are now approved of as a strategy for destination therapy. In this review, the authors describe in detail the current basic indications, functioning modalities, main limitations of surgical LAVDs, total artificial heart development, and percutaneous assist devices, trying to clarify this complex, but fascinating topic.

  6. Assistive Devices for People with Hearing, Voice, Speech, or Language Disorders (United States)

    ... Deafness Assistive Devices for People with Hearing, Voice, Speech, or Language Disorders On this page: What are ... Info Follow us on Contact Us Privacy Accessibility Freedom of Information Act Website Policies Free Publications U.S. ...

  7. 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


    . DESIGN: Non-randomized, controlled study. SETTING: Inpatient. POPULATION: 365 consecutively included THR patients. METHODS: Patients included the 3 initial month of the study underwent rehabilitation with restrictions in hip movement and a standard package of assistive devices (restricted group...... IMPACT: It is possible to reduce movement restrictions and use of assistive devices considerably. More research on safety issues is needed to elucidate the effect of unrestricted rehabilitation on hip dislocation....

  8. Initial In Vivo Evaluation of the DexAide Right Ventricular Assist Device


    Ootaki, Yoshio; Kamohara, Keiji; Akiyama, Masatoshi; Zahr, Firas; Kopcak, Michael W.; Dessoffy, Raymond AA; Massiello, Alex; Horvath, David; Chen, Ji-Feng; Benefit, Stephen; Golding, Leonard A. R.; Fukamachi, Kiyotaka


    Objectives: Despite the increasing use of left ventricular assist devices for patients with end-stage congestive heart failure, no implantable, centrifugal right ventricular assist devices (RVADs) are available for those patients with significant right ventricular failure. The DexAide RVAD was developed to provide an implantable RVAD option to surgeons. The aim of this study was to evaluate pump performance in an acute in vivo model.

  9. A novel left ventricular assist device with impeller pump and brushless motor compacted in one unit

    Institute of Scientific and Technical Information of China (English)


    The impeller pump we developed has assisted the circulation of calves for two months, but further improvements to solve the problems of bearing wear and thrombosis along the bearing are desirable. Thus we have designed a new left ventricular assist device (LVAD) with impeller pump and brushless motor compacted in one unit, for which a ceramic bearing and a purge system through the bearing have been devised. The first experiments indicate that this new device could prospectively work for more than one year.

  10. Mobile Learning as Alternative to Assistive Technology Devices for Special Needs Students (United States)

    Ismaili, Jalal; Ibrahimi, El Houcine Ouazzani


    Assistive Technology (AT) revolutionized the process of learning for special needs students during the past three decades. Thanks to this technology, accessibility and educational inclusion became attainable more than any time in the history of special education. Meanwhile, assistive technology devices remain unreachable for a large number of…

  11. Orthotopic heart transplant versus left ventricular assist device: A national comparison of cost and survival (United States)

    Mulloy, Daniel P.; Bhamidipati, Castigliano M.; Stone, Matthew L.; Ailawadi, Gorav; Kron, Irving L.; Kern, John A.


    Objectives Orthotopic heart transplantation is the standard of care for end-stage heart disease. Left ventricular assist device implantation offers an alternative treatment approach. Left ventricular assist device practice has changed dramatically since the 2008 Food and Drug Administration approval of the HeartMate II (Thoratec, Pleasanton, Calif), but at what societal cost? The present study examined the cost and efficacy of both treatments over time. Methods All patients who underwent either orthotopic heart transplantation (n = 9369) or placement of an implantable left ventricular assist device (n = 6414) from 2005 to 2009 in the Nationwide Inpatient Sample were selected. The trends in treatment use, mortality, and cost were analyzed. Results The incidence of orthotopic heart transplantation increased marginally within a 5-year period. In contrast, the annual left ventricular assist device implantation rates nearly tripled. In-hospital mortality from left ventricular assist device implantation decreased precipitously, from 42% to 17%. In-hospital mortality for orthotopic heart transplantation remained relatively stable (range, 3.8%–6.5%). The mean cost per patient increased for both orthotopic heart transplantation and left ventricular assist device placement (40% and 17%, respectively). With the observed increase in both device usage and cost per patient, the cumulative Left ventricular assist device cost increased 232% within 5 years (from $143 million to $479 million). By 2009, Medicare and Medicaid were the primary payers for nearly one half of all patients (orthotopic heart transplantation, 45%; left ventricular assist device, 51%). Conclusions Since Food and Drug Administration approval of the HeartMate II, mortality after left ventricular assist device implantation has decreased rapidly, yet has remained greater than that after orthotopic heart transplantation. The left ventricular assist device costs have continued to increase and have been

  12. Left ventricular assist device implantation strategies and outcomes


    Smith, LaVone A.; Yarboro, Leora T; Kennedy, Jamie L. W.


    Over the past 15 years, the field of mechanical circulatory support has developed significantly. Currently, there are a multitude of options for both short and long term cardiac support. Choosing the appropriate device for each patient depends on the amount of support needed and the goals of care. This article focuses on long term, implantable devices for both bridge to transplantation and destination therapy indications. Implantation strategies, including the appropriate concomitant surgerie...

  13. Non-invasive control interfaces for intention detection in active movement-assistive devices

    NARCIS (Netherlands)

    Lobo-Prat, J.; Kooren, P.N.; Stienen, A.H.A.; Herder, J.L.; Koopman, B.F.J.M.; Veltink, P.H.


    Active movement-assistive devices aim to increase the quality of life for patients with neuromusculoskeletal disorders. This technology requires interaction between the user and the device through a control interface that detects the user’s movement intention. Researchers have explored a wide variet

  14. Operations manual for the patient assist device. [to handle electrical appliances (United States)

    Schrader, M. A.


    Quadriplegic patients and multiple amputee patients are almost totally dependent on nursing personnel for any activities or interests in which they participate. A patient assist device is reported which provides patient control over electrical devices in his environment. The patient operates three switches to acquire control over a desired electrical appliance. The type switches employed are chosen to conform to patient capabilities, even when such capabilities are as limited as eye or head movements. The switch operations are sensed and converted into command signals by the patient assist device to control ten electrical appliances simulataneously and independently.

  15. [Left ventricular assist devices in cardiogenic shock and chronic refractory heart failure]. (United States)

    Genton, Audrey; Hullin, Roger; Tozzi, Piergiorgio; Cook, Stéphane; Liaudet, Lucas


    Decompensated heart failure, either acute (cardiogenic shock) or chronic (terminal heart failure) may become refractory to conventional therapy, then requiring mechanical assistance of the failing heart to improve hemodynamics. In the acute setting, aortic balloon counterpulsation is used as first line therapy. In case of failure, other techniques include the extracorporal membrane oxygenator or a percutaneous left ventricular assist device, such as the TandemHeart or the Impella. In chronic heart failure, long-term left ventricular assist devices can be surgically implanted. The continuous flow devices give here the best results. The aim of the present review article is to present with some details the various methods of mechanical left ventricle assistance to which the intensivist may be confronted in his daily practice.

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

    NARCIS (Netherlands)

    Nagata, S.F.


    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

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

    NARCIS (Netherlands)

    Nagata, S.F.


    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

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

    NARCIS (Netherlands)

    Nagata, S.F.


    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

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

    NARCIS (Netherlands)

    Nagata, S.F.


    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

  20. Computer-Assisted Communication Device for Botulinum-Intoxicated Patients (United States)


    amyotrophic lateral sclerosis , especially if mechanical ventilation is required. 6 Comparison with implanted devices A number of Brain-Computer Interface...1998) ‘Botulism in the United States: a clinical and epidemiological review’, Ann. Intern. Med., Vol. 129, pp.221–228. Simpson, L.L. (1981) ‘The

  1. 78 FR 34922 - Definition of Auditory Assistance Device (United States)


    ... Order will apply to small businesses that choose to use, manufacture, design, import, or sell part 15... the Commission's rules to permit these devices to be used by anyone at any location for simultaneous... available for inspection and copying during regular business hours in the FCC Reference Center (Room...


    Directory of Open Access Journals (Sweden)

    G. Р. Itkin


    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. 

  3. Stretchable Materials for Robust Soft Actuators towards Assistive Wearable Devices (United States)

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


    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.

  4. 14 CFR 382.121 - What mobility aids and other assistive devices may passengers with a disability bring into the... (United States)


    ... 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...

  5. Comparative kinematic and electromyographic assessment of clinician- and device-assisted sit-to-stand transfers in patients with stroke. (United States)

    Burnfield, Judith M; McCrory, Bernadette; Shu, Yu; Buster, Thad W; Taylor, Adam P; Goldman, Amy J


    Workplace injuries from patient handling are prevalent. With the adoption of no-lift policies, sit-to-stand transfer devices have emerged as one tool to combat injuries. However, the therapeutic value associated with sit-to-stand transfers with the use of an assistive apparatus cannot be determined due to a lack of evidence-based data. The aim of this study was to compare clinician-assisted, device-assisted, and the combination of clinician- and device-assisted sit-to-stand transfers in individuals who recently had a stroke. This cross-sectional, controlled laboratory study used a repeated-measures design. The duration, joint kinematics, and muscle activity of 4 sit-to-stand transfer conditions were compared for 10 patients with stroke. Each patient performed 4 randomized sit-to-stand transfer conditions: clinician-assisted, device-assisted with no patient effort, device-assisted with the patient's best effort, and device- and clinician-assisted. Device-assisted transfers took nearly twice as long as clinician-assisted transfers. Hip and knee joint movement patterns were similar across all conditions. Forward trunk flexion was lacking and ankle motion was restrained during device-assisted transfers. Encouragement and guidance from the clinician during device-assisted transfers led to increased lower extremity muscle activation levels. One lifting device and one clinician were evaluated. Clinician effort could not be controlled. Lack of forward trunk flexion and restrained ankle movement during device-assisted transfers may dissuade clinicians from selecting this device for use as a dedicated rehabilitation tool. However, with clinician encouragement, muscle activation increased, which suggests that it is possible to safely practice transfers while challenging key leg muscles essential for standing. Future sit-to-stand devices should promote safety for the patient and clinician and encourage a movement pattern that more closely mimics normal sit

  6. Capsule endoscopy in patients with cardiac pacemakers, implantable cardioverter defibrillators and left heart assist devices. (United States)

    Bandorski, Dirk; Höltgen, Reinhard; Stunder, Dominik; Keuchel, Martin


    According to the recommendations of the US Food and Drug Administration and manufacturers, capsule endoscopy should not be used in patients carrying implanted cardiac devices. For this review we considered studies indexed (until 30.06.2013) in Medline [keywords: capsule endoscopy, small bowel endoscopy, cardiac pacemaker, implantable cardioverter defibrillator, interference, left heart assist device], technical information from Given Imaging and one own publication (not listed in Medline). Several in vitro and in vivo studies included patients with implanted cardiac devices who underwent capsule endoscopy. No clinically relevant interference was noticed. Initial reports on interference with a simulating device were not reproduced. Furthermore technical data of PillCam (Given Imaging) demonstrate that the maximum transmission power is below the permitted limits for cardiac devices. Hence, impairment of cardiac pacemaker, defibrillator or left ventricular heart assist device function by capsule endoscopy is not expected. However, wireless telemetry can cause dysfunction of capsule endoscopy recording. Application of capsule endoscopy is feasible and safe in patients with implanted cardiac devices such as pacemakers, cardioverter defibrillators, and left heart assist devices. Development of new technologies warrants future re-evaluation.

  7. Towards automated assistance for operating home medical devices. (United States)

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


    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%.

  8. Modelling Framework and Assistive Device for Peripheral Intravenous Injections (United States)

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


    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.

  9. A review of assistive devices for arm balancing. (United States)

    Dunning, A G; Herder, J L


    Due to neuromuscular disorders (e.g., Duchenne Muscular Dystrophy) people often loose muscle strength and become wheelchair bound. It is important to use muscles as much as possible. To allow this, and to increase independency of patients, an arm orthosis can be used to perform activities of daily life. The orthosis compensates for the gravity force of the arm, allowing people to perform movements with smaller muscle forces. For patients, the aesthetics of the orthosis is one of the critical issues. This paper presents the state-of-the-art in passive and wearable active arm orthoses, and investigates how to proceed towards a suitable structure for a wearable passive arm orthosis, that is able to balance the arm within its natural range of motion and is inconspicuous; in the ideal case it fits underneath the clothes. Existing devices were investigated with respect to the body interface, the volume, and the workspace. According to these evaluation metrics it is investigated to what extent the devices are wearable and inconspicuous. Furthermore, the balancing principle of the devices, the architecture, force transmission through the devices, and alignment with the body joints are investigated. It appears that there is only one wearable passive orthosis presented in literature. This orthosis can perform throughout the natural workspace of the arm, but is still too bulky to be inconspicuous. The other passive orthoses were conspicuous and mounted to the wheelchair. Except one, the wearable active orthoses were all conspicuous and heavy due to a large backpack to enclose the actuators. They also could not achieve the entire natural workspace of the human arm. A future design of an inconspicuous, wearable, passive arm orthoses should stay close to the body, be comfortable to wear, and supports pronation and supination.

  10. Electron assisted glow discharges for conditioning fusion tokamak devices (United States)

    Schaubel, K. M.; Jackson, G. L.


    Glow discharge conditioning of tokamaks with graphite plasma-facing surfaces has been used to reduce impurities and obtain density control of the plasma discharge. However, a major operational disadvantage of glow conditioning is the high pressure required to initiate the glow discharge, e.g., approx. 70 mTorr for helium in DIII-D, which requires isolating auxiliary components that can not tolerate the high pressure. An electron-gun assisted glow discharge can lower breakdown pressure, possibly eliminating the necessity of isolating these auxiliary systems during glow discharge conditioning and allowing glow discharge operation at lower pressures.

  11. Biometric Device Assistant Tool: Intelligent Agent for Intrusion Detection at Biometric Device using JESS

    Directory of Open Access Journals (Sweden)

    Maithili Arjunwadkar


    Full Text Available While there are various advantages of biometric authentication process, it is vulnerable to attacks, which can decline its security. To enhance the security of biometric process, Intrusion detection techniques are significantly useful. In this paper, we have designed intelligent agent as knowledge based Biometric Device Intrusion Detection tool which is an innovative design. This intelligent agent can be located on the Biometric device. It performs intrusion detection using Operating Systems audit trail and device manager information. The system consists of a user interface module, an inference engine, a knowledgebase of illegal transactions and certified biometric devices. Inference engine is implemented using JESS which is a Java Expert System Shell.

  12. A simplified state-space model of biventricular assist device-cardiovascular system interaction. (United States)

    Koh, Vivian C A; Einly Lim; Boon Chiang Ng; Yong Kuen Ho; Lovell, Nigel H


    A simplified state-space model of biventricular assist device (BiVAD)-cardiovascular system (CVS) interaction is presented. The state-space equations includes a six-compartments CVS model incorporating the ventricles, the pulmonary and systemic circulations as well as the non-linear behavior of the valve flow, together with a left ventricular assist device (LVAD) and a right ventricular assist device (RVAD) component. The left and right pump speeds serve as the input variables for the state-space model. The model is simulated with three operational modes, i.e. (i) RVAD speed state hemodynamics is also studied with and without an outflow banding restriction. Our simulated results are validated with experimental data obtained from clinical, in vivo and in vitro studies provided in the literatures. We observed that despite its simplicity, the model is able to reproduce the observed trends in the reported studies, thus making it feasible for the development of robust yet practical control algorithms.

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


    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. Successful use of the centrifugal ventricular assist device for postcardiotomy cardiogenic shock.

    Directory of Open Access Journals (Sweden)



    Full Text Available A centrifugal pump was successfully used as a left ventricular assist device (LVAD in a 54-year-old female who developed cardiogenic shock following open heart surgery. Cardiac index prior to the LVAD support was 1.4 l/min/m2 and increased to 3.0 l/min/m2 at removal of the device, which assisted for 88h. She resumed her daily activity 10 months after the operation and is in New York Heart Association functional class I.


    The objective of the investigation is the application of, and where necessary, extension of optimal control theory to the synthesis of controllers for such cardio-circulatory assist devices. In particular, the concept of set of attainability is extended to include linear, periodic, bounded control systems and the maximum principle applied to obtain necessary and sufficient conditions for various problems. In addition to several numerical examples, the results of a large-scale hybrid simulation for a cardiovascular model and particular assist device are presented.

  16. Animal trials of a Magnetically Levitated Left-Ventricular Assist Device (United States)

    Paden, Brad; Antaki, James; Groom, Nelson


    The University of Pittsburgh/Magnetic Moments mag-lev left-ventricular assist devices (LVADs), the Streamliner HG3b and HG3c, have successfully been implanted in calves. The first was implanted for 4 hours on July 10, 1998 and the second for 34 days on August 24, 1999 respectively. The tests confirmed the feasibility of low power levitation (1.5 watts coil power) and very low blood damage in a mag-lev ventricular assist device. In this paper, we describe the unique geometry of this pump and its design. Key features of this LVAD concept are the passive radial suspension and active voice-coil thrust bearing.

  17. Assistive devices in activities of daily living used by persons with age-related macular degeneration: a population study of 85-year-olds living at home. (United States)

    Dahlin Ivanoff, S; Sonn, U


    The purpose of this study was to investigate the overall use of assistive devices among persons with age-related macular degeneration (ARMD) and how it is related to dependence in daily activities. This was a retrospective, descriptive, cross-sectional population study of 85-year-olds. The most common category of assistive devices was bathing devices followed by mobility devices. The overall use of assistive devices was 82%, and around 80% of the device users were independent in activities of daily living. They were multiple device users (57%) and used more mobility devices and personal assistance in mobility. In conclusion, the ARMD group comprises very frequent users of assistive devices and uses assistive devices to remain independent. This implies that health services should provide assistive devices at an early stage in the disablement process to avoid the development of dependence and should consider the likelihood of multiple health problems when assessing the needs of assistive devices among persons with ARMD.

  18. Development of an Inlet Pressure Sensor for Control in a Left Ventricular Assist Device



    A Tesla type continuous flow left ventricular assist device (VAD) has been designed by Penn State and Advanced Bionics, Inc. (ABI). When a continuous flow device is employed, care must be taken to limit low pressures in the ventricle that can produce an obstruction to the inlet cannula or trigger arrhythmias. Design of an inexpensive, semi-conductor strain gage inlet pressure sensor to detect suction has been completed. The research and design analysis included finite element modeling of the ...

  19. Myocardial recovery in peri-partum cardiomyopathy after continuous flow left ventricular assist device

    Directory of Open Access Journals (Sweden)

    Lund Lars H


    Full Text Available Abstract Left ventricular assist devices (LVADs offer effective therapy for severe heart failure (HF as bridge to transplantation or destination therapy. Rarely, the sustained unloading provided by the LVAD has led to cardiac reverse remodelling and recovery, permitting explantation of the device. We describe the clinical course of a patient with severe peri-partum cardiomyopathy (PPCM rescued with a continuous flow LVAD, who experienced recovery and explantation. We discuss assessment of and criteria for recovery.

  20. Clinical, Molecular and Genetic Changes in Response to a Left Ventricular Assist Device


    Hall, Jennifer L.; Fermin, David R.; Birks, Emma J.; Barton, Paul J. R.; Slaughter, Mark; Eckman, Peter; Hideo A. Baba; Wohlschlaeger, Jeremias Jeremias; Miller, Leslie W.


    The use of left ventricular assist devices (LVADs) in treating patients with end stage heart failure has increased significantly in recent years, both as a bridge to transplant and as destination therapy in those who are ineligible for cardiac transplantation. This increase is based largely on the results of several recently completed clinical trials with the new second generation continuous flow devices that showed significant improvement in survival, functional capacity, and quality of life...

  1. The embodiment of assistive devices-from wheelchair to exoskeleton (United States)

    Pazzaglia, Mariella; Molinari, Marco


    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.

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


    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.

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

    DEFF Research Database (Denmark)

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


    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...

  4. Radiofrequency ablation therapy of intractable ventricular tachycardia present with a left ventricular assist device

    DEFF Research Database (Denmark)

    Nielsen, Jan Møller; Kristiansen, Steen Buus; Gerdes, Christian;


    Ventricular tachycardia (VT) occurs in up to 59% of patients with left ventricular assist devices (LVAD). In some of these patients, the VT cannot be managed medically or by implantable cardioverter-defibrillator. In this case, a 66-year-old male was successfully treated with radiofrequency...

  5. 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;


    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....

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

    Directory of Open Access Journals (Sweden)

    Yiannis Koumpouros


    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.


    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.

  8. Left ventricular assist device and heart transplantation in hemophilia a patient. (United States)

    Quader, Mohammed; Rusina, Zane; Lewis, Neil P; Martin, Lisa; Katlaps, Gundars


    We report here a hemophilia patient who was bridged with a left ventricle assist device and later received heart transplantation. Preparation for surgery with factor VIII supplementation, intraoperative conduct of surgery, and challenges of postoperative course are described with a brief literature review.

  9. Effect of Using Assist Devices on Exam Completion Questions among Thai College Students (United States)

    Schneider, Arthur E.


    Action research was undertaken to begin to explore the possibility of improving second-language Thai college student performance on completion questions by using bolded and underscored words in test item stems, called "assist devices." This intervention was designed to focus student attention on key terms. Twenty-one students, in an…

  10. Assistive Devices for Children with Functional Impairments: Impact on Child and Caregiver Function (United States)

    Henderson, Stacey; Skelton, Heather; Rosenbaum, Peter


    Functional impairments can limit a child's ability to participate in the experiences of childhood. This "deprivation" can, in turn, have a negative effect on such children's development, academic performance, and quality of life, as well as on the lives of their caregivers and families. Many adults use assistive devices to overcome functional…


    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. Methods

  12. AUDIS wear: a smartwatch based assistive device for ubiquitous awareness of environmental sounds. (United States)

    Mielke, Matthias; Bruck, Rainer


    A multitude of assistive devices is available for deaf people (i.e. deaf, deafened, and hard of hearing). Besides hearing and communication aids, devices to access environmental sounds are available commercially. But the devices have two major drawbacks: 1. they are targeted at indoor environments (e.g. home or work), and 2. only specific events are supported (e.g. the doorbell or telephone). Recent research shows that important sounds can occur in all contexts and that the interests in sounds are diverse. These drawbacks can be tackled by using modern information and communication technology that enables the development of new and improved assistive devices. The smartwatch, a new computing platform in the form of a wristwatch, offers new potential for assistive technology. Its design promises a perfect integration into various different social contexts and thus blends perfectly into the user's life. Based on a smartwatch and algorithms from pattern recognition, a prototype for awareness of environmental sounds is presented here. It observes the acoustic environment of the user and detects environmental sounds. A vibration is triggered when a sound is detected and the type of sound is shown on the display. The design of the prototype was discussed with deaf people in semi-structured interviews, leading to a set of implications for the design of such a device.

  13. 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 (United States)

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


    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.

  14. Upper limb impairment is associated with use of assistive devices and unemployment in multiple sclerosis. (United States)

    Marrie, Ruth Ann; Cutter, Gary R; Tyry, Tuula; Cofield, Stacey S; Fox, Robert; Salter, Amber


    Individuals with multiple sclerosis (MS) frequently suffer from impaired sensory function, reduced strength and tremor in the upper limbs, which may interfere with upper limb function. However, upper limb impairment in MS is under-recognized and understudied. We aimed to evaluate the prevalence of upper limb impairment in a large sample of persons with MS; the association between upper limb function and employment status in MS; and the frequency of use of assistive devices aimed at addressing upper limb impairments. We surveyed participants in the North American Research Committee on Multiple Sclerosis (NARCOMS) Registry regarding upper limb function using the ABILHAND questionnaire, and asked about use of assistive devices intended to improve the performance on upper limb activities. We evaluated the association between ABILHAND scores and current employment status using multivariable logistic regression analysis, and the association between ABILHAND scores and the use of an assistive device. Of 7463 eligible respondents, 5846 (78.3%) were female and mean (SD) age of 57.4 (10.2) years. The median (IQR) score on the ABILHAND was 45 (39-46). Higher levels of disability, as measured by the PDDS, correlated moderately with lower (worse) scores on the ABILHAND (r=-0.50; 95%CI: -0.48, -0.52). Over half of participants reported that they possessed an assistive device to aid upper limb function (3914, 56.0%). Older age, female sex, greater ambulatory disability, higher levels of fatigue, sensory impairment, spasticity and cognitive impairment, and visiting an occupational therapist were independently associated with increased odds of using an assistive device. After accounting for disability, perceived cognitive impairment, and fatigue, impaired upper limb function was associated with decreased odds of being employed (OR/1 point rise in ABILHAND 0.97; 95%CI: 0.96, 0.98). Upper limb impairment is common in older MS patients, and adversely affects the ability to perform

  15. Pulsed or continuous flow in long-term assist devices: a debated topic. (United States)

    Sansone, Fabrizio; Zingarelli, Edoardo; Flocco, Roberto; Dato, Guglielmo Mario Actis; Parisi, Francesco; Punta, Giuseppe; Forsennati, Pier Giuseppe; Bardi, Gian Luca; Del Ponte, Stefano; Patanè, Francesco; Casabona, Riccardo


    The end-stage cardiomyopathy is an increasing worldwide problem. Cardiac transplantation lacks sufficient donors to treat all patients, and there is thus debate about alternative strategies. The use of left ventricular assist devices for long-term support is increasing with a positive impact on patient survival. Although there is an ongoing debate regarding the risks and benefits of maintaining pulsatile flow during long-term ventricular assist device support, there has been a significant move towards implantation of continuous flow devices due to the lower surgical morbidity and better long-term reliability of these pumps. The following is a review of the literature on continuous and pulsatile flow for long-term support. Starting from the definition of flow, we analyze the current evidence and consider gastrointestinal complications.

  16. Ventricular assist devices for heart failure: a focus on patient selection and complications

    Directory of Open Access Journals (Sweden)

    Cipriani M


    Full Text Available Manlio Cipriani, Vincenzo De Simone, Luciana D'Angelo, Enrico Perna, Marzia Lilliu, Virginia Bovolo, Fabrizio Oliva, Maria Frigerio Cardiovascular and Thoracic Department, A De Gasperis Niguarda Ca' Granda Hospital, Milan, Italy Abstract: Heart transplantation represents the “gold standard” for the treatment of patients with end-stage heart failure, but remains challenged by inadequate donor supply, finite graft survival, and long-term complications arising from immunosuppressive therapy. In addition, a lot of patients waiting for a heart transplant experience clinical deterioration, and other patients become ineligible to undergo this treatment due to their age or relevant comorbidities. Left ventricular assist devices have emerged as a valid therapeutic option for advanced heart failure. In recent years, we have seen significant advances not only in the technologies available, but also in patient selection, indications for use, and management after implantation. Consequently, there has been an increase in the number of implants and an improvement in the survival rate and quality of life for these patients. At the same time, there are new challenges on the horizon. Patient selection is a difficult process, based on clinical and imaging parameters and risk scores, and more data are needed to refine patient selection criteria and the timing of the implant. Left ventricular assist device-related complications are still a serious problem, causing adverse events and hospital readmissions. Continuous progress in the development of these implantable devices, such as a further reduction in size and hopefully the abolition of the external driveline, will probably make ventricular assist devices an option also for less advanced stages of heart failure. Here, we discuss the current indications for left ventricular assist device implantation, patient selection criteria, and the most frequent complications associated with these devices. Keywords

  17. [Intelligent operating room suite : From passive medical devices to the self-thinking cognitive surgical assistant]. (United States)

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


    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.

  18. Integration of augmented reality and assistive devices for post-stroke hand opening rehabilitation. (United States)

    Luo, Xun; Kline, Tiffany; Fischer, Heidi; Stubblefield, Kathy; Kenyon, Robert; Kamper, Derek


    Impairment of hand function is prevalent among stroke survivors, motivating the search for effective rehabilitation therapy. Recent studies have suggested that for upper extremity functional recovery, repetitive training with virtual reality is helpful. Repetitive training can be facilitated with assistance from mechanical devices. Thus, we have developed a training environment that integrates augmented reality (AR) with assistive devices for post-stroke hand rehabilitation. The AR element of our environment utilizes head mounted display and virtual objects for reach-and-grasp task training. The assistive device consists of either a body-powered orthosis (BPO) or a pneumatic-powered device (PPD), both of which are incorporated into gloves. This environment can be easily set up and calibrated, is customizable for individual users, and requires active user participation. Additionally, it can be used with both real and virtual objects, as desired. We are currently conducting pilot case studies to assess ease of use and efficacy. At present, one stroke survivor from each of the three training conditions, AR-with-BPO, AR-with-PPD and AR-only (acting as the control), has completed the 6-week training paradigm. Preliminary findings suggest user acceptance of the technology and some potential for beneficial effects.

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

    Directory of Open Access Journals (Sweden)

    Maria Dagioglou


    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.

  20. Effects of Interaction Between Ventricular Assist Device Assistance and Autoregulated Mock Circulation Including Frank-Starling Mechanism and Baroreflex. (United States)

    Jansen-Park, So-Hyun; Mahmood, Mohammad Nauzef; Müller, Indra; Turnhoff, Lisa Kathrin; Schmitz-Rode, Thomas; Steinseifer, Ulrich; Sonntag, Simon Johannes


    A mock heart circulation loop (MHCL) is a hydraulic model simulating the human circulatory system. It allows in vitro investigations of the interaction between cardiac assist devices and the human circulatory system. In this study, a preload sensitive MHCL, the MHCLAUTO , was developed to investigate the interaction between the left ventricle and left ventricular assist devices (LVADs). The Frank-Starling mechanism was modeled by regulating the stroke volume (SV) based on the measured mean diastolic left atrial pressure (MLAPdiast ). The baroreflex autoregulation mechanism was implemented to maintain a constant mean aortic pressure (MAP) by varying ventricular contractility (Emax ), heart rate (HR), afterload/systemic vascular resistance (SVR) and unstressed venous volume (UVV). The DP3 blood pump (Medos Medizintechnik GmbH) was used to simulate the LVAD. Characteristic parameters were measured in pathological conditions both with and without LVAD to assess the hemodynamic effect of LVAD on the MHCLAUTO . The results obtained from the MHCLAUTO show a high correlation to literature data. The study demonstrates the possibility of using the MHCLAUTO as a research tool to better understand the physiological interactions between cardiac implants and human circulation.

  1. In vitro evaluation of an external compression device for fontan mechanical assistance. (United States)

    Valdovinos, John; Shkolyar, Eugene; Carman, Gregory P; Levi, Daniel S


    While Fontan palliation in the form of the total cavopulmonary connection has improved the management of congenital single ventricle physiology, long-term outcomes for patients with this disease are suboptimal due to the lack of two functional ventricles. Researchers have shown that ventricular assist devices (VADs) can normalize Fontan hemodynamics. To minimize blood contacting surfaces of the VAD, we evaluated the use of an external compression device (C-Pulse Heart Assist System, Sunshine Heart Inc.) as a Fontan assist device. A mock circulation was developed to mimic the hemodynamics of a hypertensive Fontan circulation in a pediatric patient. The Sunshine C-Pulse compression cuff was coupled with polymeric valves and a compressible tube to provide nonblood-contacting pulsatile flow through the Fontan circulation. The effect of the number, one or two, and placement of valves, before or after the compression cuff, on inferior vena cava pressure (IVCP) was studied. In addition, the effect of device inflation volume and compression rate on maintaining low IVCP was investigated. With one valve located before the cuff, the device was unable to maintain an IVCP below 15.5 mm Hg. With two valves, the C-Pulse was able to maintain IVCP as low as 8.5 mm Hg. The C-Pulse provided pulsatile flow and pressure through the pulmonary branch of the mock circulation with a pulse pressure of 16 mm Hg and 180 mL/min additional flow above unassisted flow. C-Pulse compression reduced IVCP below 12 mm Hg with 13 cc inflation volume and compression rates above 105 bpm. This application of an external compression device combined with two valves has potential for use as an artificial right ventricle by maintaining low IVCP and providing pulsatile flow through the lungs.

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

    Directory of Open Access Journals (Sweden)

    Everett Christopher B


    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.

  3. Bailout transcatheter closure of patent foramen ovale for refractory hypoxaemia after left ventricular assist device implantation. (United States)

    Fischer, Quentin; Kirsch, Matthias; Brochet, Eric; Juliard, Jean-Michel


    We describe the interdisciplinary management of a 59-year old man with ischaemic cardiomyopathy on a HeartMate II left ventricular assist device (LVAD) and temporary right extracorporeal membrane oxygenation (ECMO) as a bridge-to-heart transplantation. He suffered refractory hypoxaemia due to massive right-to-left shunting by a patent foramen ovale (PFO), diagnosed after weaning off of temporary right ECMO. Percutaneous closure of the PFO was successfully achieved with an Amplatzer septal occluder device, which allowed the patient's extubation and departure from hospital. The patient received heart transplantation 7 weeks after LVAD implantation and was discharged from the intensive care unit 2 weeks after transplantation.

  4. Psychological distress in patients with a left ventricular assist device and their partners

    DEFF Research Database (Denmark)

    Brouwers, Corline; Denollet, Johan; Caliskan, Kadir


    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, d......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...... compared to LVAD patients at baseline (48% vs. 23%, p=0.03) and 3 months follow-up (44% vs. 15%, p=0.02), but not at 6 months follow-up (p=0.43). No differences were found for depression and PTSD (ps>0.05). Scores between the LVAD patients and partners showed only a significant correlation at baseline...

  5. Ventricular assist device for failing systemic ventricle in an adult with prior mustard procedure. (United States)

    Neely, Robert C; Davis, Robert Patrick; Stephens, Elizabeth H; Takayama, Hiroo; Khalpey, Zain; Ginns, Jonathan; Lee, Sun Hi; Chen, Jonathan


    The Mustard procedure is a palliative surgical procedure used to repair complete transposition of the great arteries. Cardiac transplantation remains the only definitive therapy for patients who develop heart failure after a Mustard procedure. However, pulmonary hypertension represents a major hemodynamic contraindication. The use of a ventricular assist device as destination therapy has not yet been established after a Mustard procedure. Here, we present the case of a 41-year-old patient who presented with systemic right ventricular failure following Mustard procedure complicated by pulmonary hypertension. The patient received a HeartMate II (Thoratec, Pleasanton, CA) ventricular assist device as a bridge to decision. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  6. Hemodynamic stress echocardiography in patients supported with a continuous-flow left ventricular assist device

    DEFF Research Database (Denmark)

    Andersen, Mads; Gustafsson, Finn; Madsen, Per Lav


    Functional assessment of continuous-flow left ventricular assist devices (LVADs) is usually performed with the patient at rest. This study compared echocardiographic indices of contraction and filling pressure with invasive measures in 12 ambulatory LVAD patients undergoing symptom-limited bicycl...... parallel with cardiac output) and diastolic E/e' ratio decreased (correlating inversely with diastolic pulmonary artery pressure). These findings emphasize the potential role of exercise echocardiography in studying exercise hemodynamics in LVAD patients....

  7. Combined Application of Circulatory Assist Devices Following Cardiac Arrest in Patients after Cardiac Surgery

    Institute of Scientific and Technical Information of China (English)

    Huang Huanlei; Xiao Xuejun; Wu Ruobin; Ruixin; Cheng Anheng; Zhang Xiaohua; Luo Zhengxiang


    Objectives To evaluateretrospectively the potential benefits of combined utilization of various assisted circulation devices in cardiac arrest patients who did not respond to conventional cardiopulmonary cerebral resuscitation (CPCR). Methods Assisted circulation devices,including emergency cardiopulmonary bypass (ECPB), intra-aortic balloon pump (IABP), and left ventricular assist device (LVAD), were applied to 16 adult patients who had cardiac arrest 82 min~56 h after open heart surgery and did not respond to 20 min or longer conventional CPCR. ECPB was applied to 2 patients, ECPB plus IABP to 8 patients, ECPB plus IABP and LVAD to 6 patients. Results One patient recovered fully and one patient died. Of the other 14 patients, 13 resumed spontaneous cardiac rhythm and one did not; none of them could be weaned from ECPB.Further treatment of the 14 patients with combinations of assisted circulation devices enabled 6 patients to recover. One of the 7 recovered patients died of reoccurring cardiac arrest after 11 days; the other 6 were discharged in good condition and were followed up for 3~49 months (mean =22 months). Of the 6 discharged patients one suffered cerebral embolism during LVAD treatment, resulting in mild limitation of mobility of the right limbs; the other 5 never manifested any central nervous system complications. There was no late deaths giving a 37.5% (6/16) long-term survival rate. Conclusions ECPB could effectively reestablish blood circulation and oxygen supply, rectify acidosis,and improve internal milieu. The combined utilization of ECPB, IABP, and LVAD reduces the duration of ECPB, improves the incidence of recovery, and offers beneficial alternatives to refractory cardiac arrest patients.

  8. Plutonium-238: an ideal power source for intracorporeal ventricular assist devices? (United States)

    Tchantchaleishvili, Vakhtang; Bush, Bryan S; Swartz, Michael F; Day, Steven W; Massey, H Todd


    Ventricular assist devices emerged as a widely used modality for treatment of end-stage heart failure; however, despite significant advances, external energy supply remains a problem contributing to significant patient morbidity and potential mortality. One potential solution is using the nuclear radioisotope Plutonium-238 as a power source. Given its very high energy density and long half-life, Plutonium-238 could eventually allow a totally intracorporeal ventricular assist system that lasts for the patient's lifetime. Risks, such as leakage and theft identified decades ago, still remain. However, it is possible that newer technologies could be used to overcome the system complexity and unreliability of the previous generations of nuclear-powered mechanical assist systems. Were it not for the remaining safety risks, Plutonium-238 would be an ideal energy source for this purpose.

  9. Stability analysis of electrical powered wheelchair-mounted robotic-assisted transfer device

    Directory of Open Access Journals (Sweden)

    Hongwu Wang, PhD


    Full Text Available The ability of people with disabilities to live in their homes and communities with maximal independence often hinges, at least in part, on their ability to transfer or be transferred by an assistant. Because of limited resources and the expense of personal care, robotic transfer assistance devices will likely be in great demand. An easy-to-use system for assisting with transfers, attachable to electrical powered wheelchairs (EPWs and readily transportable, could have a significant positive effect on the quality of life of people with disabilities. We investigated the stability of our newly developed Strong Arm, which is attached and integrated with an EPW to assist with transfers. The stability of the system was analyzed and verified by experiments applying different loads and using different system configurations. The model predicted the distributions of the system’s center of mass very well compared with the experimental results. When real transfers were conducted with 50 and 75 kg loads and an 83.25 kg dummy, the current Strong Arm could transfer all weights safely without tip-over. Our modeling accurately predicts the stability of the system and is suitable for developing better control algorithms to enhance the safety of the device.

  10. Stability analysis of electrical powered wheelchair-mounted robotic-assisted transfer device. (United States)

    Wang, Hongwu; Tsai, Chung-Ying; Jeannis, Hervens; Chung, Cheng-Shiu; Kelleher, Annmarie; Grindle, Garrett G; Cooper, Rory A


    The ability of people with disabilities to live in their homes and communities with maximal independence often hinges, at least in part, on their ability to transfer or be transferred by an assistant. Because of limited resources and the expense of personal care, robotic transfer assistance devices will likely be in great demand. An easy-to-use system for assisting with transfers, attachable to electrical powered wheelchairs (EPWs) and readily transportable, could have a significant positive effect on the quality of life of people with disabilities. We investigated the stability of our newly developed Strong Arm, which is attached and integrated with an EPW to assist with transfers. The stability of the system was analyzed and verified by experiments applying different loads and using different system configurations. The model predicted the distributions of the system's center of mass very well compared with the experimental results. When real transfers were conducted with 50 and 75 kg loads and an 83.25 kg dummy, the current Strong Arm could transfer all weights safely without tip-over. Our modeling accurately predicts the stability of the system and is suitable for developing better control algorithms to enhance the safety of the device.

  11. 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


    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....

  12. A device for training and computer-assisted application of panretinal photocoagulation (United States)

    Barriga, Eduardo S.; Russell, Stephen; Abramoff, Michael; Brittain, Robert; Nguyen, Phong; Soliz, Peter


    To become highly proficient at a given surgical procedure and to reduce risk to patients, physicians must gain experience through a number means. Today optical training devices based on the actual surgical device coupled with computer models can provide the required realism to provide highly effective training. This paper presents a optical system that will be used for training residents to perform panretinal photocoagulation (PRP), a laser surgical procedure for treating the retina. The system will naturally evolve into a computer-assisted device for performing PRP. With the system described herein, simulations are created in the Umbra modeling and simulation framework. The simulation is composed of four building blocks: Pre-operation planning, multi-modality image registration, tracking the patient's eye movement, and positioning the laser according to the pre-planned aim points. A prototype simulation was developed to demonstrate a realistic depiction of the PRP the procedure. The ultimate goal of this project is to integrate the software into an existing ophthalmic device to increase the accuracy of the laser application procedure by providing computer-assisted surgery.

  13. Objective and perceptual comparisons of two bluetooth hearing aid assistive devices. (United States)

    Clark, Jackie L; Pustejovsky, Carmen; Vanneste, Sven


    With the advent of Bluetooth technology, many of the assistive listening devices for hearing have become manufacturer specific, with little objective information about the performance provided. Thirty native English-speaking adults (mean age 29.8) with normal hearing were tested pseudo-randomly with two major hearing aid manufacturers' proprietary Bluetooth connectivity devices paired to the accompanying manufacturer's specific hearing aids. Sentence recognition performance was objectively measured for each system with signals transmitted via a land-line to the same iPhone in two conditions. There was a significant effect of participant's performance according to listening condition. There was no significant effect between device manufacturers according to listening condition, but there was a significant effect in participant's perception of "quality of sound". Despite differences in signal transmission for each devise, when worn by participants both the systems performed equally. In fact, participants expressed personal preferences for specific technology that was largely due to their perceived quality of sound while listening to recorded signals. While further research is necessary to investigate other measures of benefit for Bluetooth connectivity devices, preliminary data suggest that in order to ensure comfort and compatibility, not only should objective measures of the patient benefit be completed, but also assessing the patient's perception of benefit is equally important. Implications for Rehabilitation All professionals who work with individuals with hearing loss, become aware of the differences in the multiple choices for assistive technology readily available for hearing loss. With the ever growing dispensing of Bluetooth connectivity devices coupled to hearing aids, there is an increased burden to determine whether performance differences could exist between manufacturers. There is a growing need to investigate other measures of benefit for Bluetooth

  14. Clinical application of BVS5000 left ventricular assist device in heart failure patients

    Institute of Scientific and Technical Information of China (English)

    LUO Xin-jin; HU Sheng-shou; SUN Han-song; XU Jian-ping; LIU Ping; ZHENG Zhe; MA Wei-guo; ZHANG Yan


    Background Mechanical ventricular assistance is an important therapeutic method for severe heart failure patients. A variety of ventricular assist devices have been designed for use. The purpose of this report was to describe the experience of using Abiomed BVS5000 as a means of left ventricular support as a clinical treatment for heart failure patients.Methods From February 2004 to April 2006, 12 male patients were supported with Abiomed BVS5000 left ventricular assist device (LVAD) at Fu Wai Hospital. The average age was (55.2+9.6) years (range 39 to 68 years). The mean body surface area was (1.76±0.1) m2 (range 1.6 to 1.9 m2 ). Devices were inserted for post-cardiotomy shock after coronary artery bypass graft in 11 patients (92%) and in 1 dilated cardiomyopathy patient for acute cardiogenic shock. Modified cannulation methods by inserting the arterial cannulae in femoral artery and inserting the venous cannula in left atrium through a segment of bovine jugular vein were used in 7 patients. In this way, the device could be taken off without re-sternotomy when support was finished. A comparison was made between the modified method and routine left atrium-to-ascending aorta cannulating method.Results The median duration of support was 5 (3-43) days, with support flow rate of 3.8-4.5 L/min. There were 9 (75%)patients weaned from support and 8 (67%) patients discharged from the hospital. Four (33%) patients were dead. The most common morbidity was adverse neurological events. There is no statistical difference between modified and routine method on average in BVS5000 support duration, in assisted flow rate, in mechanical ventilation duration, in the intensive care unit stay and thoracic drainage.Conclusions The Abiomed BVS5000 is valuable to support patients with acute cardiogenic shock for short-term use.By the modified cannulating method, the weaning procedure can be effectively simplified. Optimization of inserting indication remains challenging and attributes to

  15. Remission of chronic anthracycline-induced heart failure with support from a continuous-flow left ventricular assist device. (United States)

    Khan, Nadeem; Husain, Syed Arman; Husain, Syed Iman; Khalaf, Natalia; George, Joggy; Raissi, Farshad; Segura, Ana Maria; Kar, Biswajit; Bogaev, Roberta C; Frazier, O H


    We report the case of a patient who had chronic anthracycline-induced cardiomyopathy that was reversed after treatment with a left ventricular assist device. A 29-year-old woman had undergone anthracycline-based chemotherapy as a teenager in 1991 and 1992 and received a diagnosis of dilated cardiomyopathy 10 years later. Optimal medical therapy had initially controlled the symptoms of heart failure. However, in June 2006, the symptoms worsened to New York Heart Association functional class IV status. We implanted a continuous-flow left ventricular assist device as a bridge to cardiac transplantation; of note, a left ventricular core biopsy at that time showed no replacement fibrosis. The patient's clinical status improved thereafter, enabling left ventricular assist device ex-plantation after 17 months. To our knowledge, this is the first report of the use of left ventricular assist device support to reverse chronic anthracycline-induced heart failure.

  16. Assistive technology devices for toileting and showering used in spinal cord injury rehabilitation - a comment on terminology. (United States)

    Friesen, Emma L; Theodoros, Deborah; Russell, Trevor G


    A review of assistive technologies, products and devices for toileting and showering identified at least 15 separate terms across all studies, with another two identified in subsequent studies. Terms are often used interchangeably, and are often not defined or described. Inconsistencies in terminology affect the quality of evidence available to policy makers, researchers and clinicians. Researchers are encouraged to provide clear definitions and descriptions of assistive technologies, products and devices for toileting and showering under investigation. Implications for Rehabilitation At least 17 different terms have been identified for assistive technologies, products and devices for toileting and showering. Inconsistencies in terminology make comparisons between studies difficult, and therefore affect the quality of evidence available to policy makers, researchers and clinicians. Providing clear definitions and descriptions of assistive technologies, products and devices for toileting and showering under investigation is encouraged.

  17. In vivo quantification of intraventricular flow during left ventricular assist device support (United States)

    Vu, Vi; Wong, Kin; Del Alamo, Juan; Aguilo, Pablo M. L.; May-Newman, Karen; Department of Bioengineering, San Diego State University Collaboration; Department of Mechanical; Aerospace Engineering, University of California San Diego Collaboration; Mechanical Assist Device Program, Sharp Memorial Hospital Collaboration


    Left ventricular assist devices (LVADs) are mechanical pumps that are surgically connected to the left ventricle (LV) and aorta to increase aortic flow and end-organ perfusion. Clinical studies have demonstrated that LVADs improve patient health and quality of life and significantly reduce the mortality of cardiac failure. However, In the presence of left ventricular assisted devices (LVAD), abnormal flow patterns and stagnation regions are often linked to thrombosis. The aim of our study is to evaluate the flow patterns in the left ventricle of the LVAD-assisted heart, with a focus on alterations in vortex development and blood stasis. To this aim, we applied color Doppler echocardiography to measure 2D, time resolved velocity fields in patients before and after implantation of LVADs. In agreement with our previous in vitro studies (Wong et al., Journal of Biomechanics 47, 2014), LVAD implantation resulted in decreased flow velocities and increased blood residence time near the outflow tract. The variation of residence time changes with LVAD operational speed was characterized for each patient.

  18. Design and User Evaluation of a Wheelchair Mounted Robotic Assisted Transfer Device

    Directory of Open Access Journals (Sweden)

    Garrett G. Grindle


    Full Text Available Purpose. The aim of this study is to describe the robotic assisted transfer device (RATD and an initial focus group evaluation by end users. The purpose of the device is to aid in the transfers of people with disabilities to and from their electric powered wheelchair (EPW onto other surfaces. The device can be used for both stand-pivot transfers and fully dependent transfers, where the person being transferred is in a sling and weight is fully on the robot. The RATD is fixed to an EPW to allow for its use in community settings. Method. A functional prototype of the RATD was designed and fabricated. The prototype was presented to a group of 16 end users and feedback on the device was obtained via a survey and group discussion. Results. Thirteen out of sixteen (83% participants agreed that it was important to develop this type of technology. They also indicated that user, caregiver, and robotic controls were important features to be included in the device. Conclusions. Participants in this study suggested that they would be accepting the use of robotic technology for transfers and a majority did not feel that they would be embarrassed to use this technology.

  19. In vitro pulsatility analysis of axial-flow and centrifugal-flow left ventricular assist devices. (United States)

    Stanfield, J Ryan; Selzman, Craig H


    Recently, continuous-flow ventricular assist devices (CF-VADs) have supplanted older, pulsatile-flow pumps, for treating patients with advanced heart failure. Despite the excellent results of the newer generation devices, the effects of long-term loss of pulsatility remain unknown. The aim of this study is to compare the ability of both axial and centrifugal continuous-flow pumps to intrinsically modify pulsatility when placed under physiologically diverse conditions. Four VADs, two axial- and two centrifugal-flow, were evaluated on a mock circulatory flow system. Each VAD was operated at a constant impeller speed over three hypothetical cardiac conditions: normo-tensive, hypertensive, and hypotensive. Pulsatility index (PI) was compared for each device under each condition. Centrifugal-flow devices had a higher PI than that of axial-flow pumps. Under normo-tension, flow PI was 0.98 ± 0.03 and 1.50 ± 0.02 for the axial and centrifugal groups, respectively (p centrifugal pumps, respectively (p = 0.01). Under hypotension, PI was 0.73 ± 0.02 and 0.78 ± 0.02 for the axial and centrifugal groups, respectively (p = 0.13). All tested CF-VADs were capable of maintaining some pulsatile-flow when connected in parallel with our mock ventricle. We conclude that centrifugal-flow devices outperform the axial pumps from the basis of PI under tested conditions.

  20. Injury risk compensation in children with disabilities: could assistive technology devices have a dark side? (United States)

    Ryan, Stephen E


    This review article investigates the role of assistive technology (AT) devices and other contextual aspects as unintentional injury risk factors in children with disabilities. A literature review was conducted to identify and review empirical studies that examined the role of AT devices, protective equipment (PE), and other consumer products in the risk-taking behaviors of children and their parents. Nine original empirical studies and one systematic review examining changes in the risk-taking behaviors or injury levels associated with children's PE and other products were identified and critically reviewed. None of the articles specifically addressed the compensatory effect of AT devices. Since evidence of changes in the risk tolerance of children and their parents after the introduction of PE and other products for children exists, it is conceivable under certain conditions that AT devices could interact with other known risk factors to promote injury risk-taking behaviors in children and their parents. Outcomes of this review and current thinking about the interaction of health conditions and contextual factors provide a theoretical underpinning to explore the causal association among unintentional injury risk factors and AT device use by children with disabilities.

  1. Design and user evaluation of a wheelchair mounted robotic assisted transfer device. (United States)

    Grindle, Garrett G; Wang, Hongwu; Jeannis, Hervens; Teodorski, Emily; Cooper, Rory A


    The aim of this study is to describe the robotic assisted transfer device (RATD) and an initial focus group evaluation by end users. The purpose of the device is to aid in the transfers of people with disabilities to and from their electric powered wheelchair (EPW) onto other surfaces. The device can be used for both stand-pivot transfers and fully dependent transfers, where the person being transferred is in a sling and weight is fully on the robot. The RATD is fixed to an EPW to allow for its use in community settings. A functional prototype of the RATD was designed and fabricated. The prototype was presented to a group of 16 end users and feedback on the device was obtained via a survey and group discussion. Thirteen out of sixteen (83%) participants agreed that it was important to develop this type of technology. They also indicated that user, caregiver, and robotic controls were important features to be included in the device. Participants in this study suggested that they would be accepting the use of robotic technology for transfers and a majority did not feel that they would be embarrassed to use this technology.

  2. Experimental studies on the human gait using a tethered pelvic assist device (T-PAD). (United States)

    Vashista, Vineet; Mustafa, S K; Agrawal, Sunil K


    This paper presents the prototype of a novel tethered pelvic assist device (T-PAD). This is a purely passive device, consisting of a set of elastic tethers with one end attached to a hip brace worn by a subject walking on a treadmill, and the other end attached to a fixed frame surrounding the subject. T-PAD offers the flexibility of varying the assistance required on the pelvis by changing the configuration of the tether attachment locations, number of tethers and tether elasticity. Experimental studies were conducted using a full and a partial pelvic constraint configuration of T-PAD, with varying tether elasticity. The studies were aimed at observing the effect of T-PAD on the human gait. Results show that T-PAD reduced the range-of-motion for the pelvic angles with increase of tether elasticity. However, it had mixed effects on the range-of-motion of the hip angles, but negligible effect on the knee and ankle joint angles. Overall, T-PAD shows potential as a low-cost pelvic support device with pelvic motion control capabilities, and can work in tandem with existing gait trainers.

  3. [Rise of the machines? Left ventricular assist devices for treatment of severe heart failure]. (United States)

    Ujeyl, A; Krüger, M


    The use of left ventricular assist devices (LVAD) as a treatment for severe heart failure has gained momentum in recent years. Even at this stage the number of worldwide LVAD implantations far exceeds the volume of heart transplantations in view of the chronic shortage of donor organs. Third generation continuous flow assist devices have helped to improve survival, quality of life and symptom burden of heart failure patients in comparison to a regimen of optimal medication management. Alongside bridging to transplantation, destination therapy has become an established strategy of LVAD implantation. A careful patient selection process is crucial for a good clinical outcome after device implantation and risk assessment for postoperative right ventricular failure is of particular importance in this context. The rate of hospitalization during LVAD support is still high, despite the step-wise attempts to widen the indications to less severely ill heart failure patients. An effective perioperative and postoperative management will help to lower the incidence of complications (e.g. bleeding, infections, thromboembolic events and right ventricular failure) and to improve the encouraging results of mechanical circulatory support.

  4. Simultaneous ramp right heart catheterization and echocardiography in a ReliantHeart left ventricular assist device (United States)

    Banerjee, Dipanjan; Dutt, Debleena; Duclos, Sebastien; Sallam, Karim; Wheeler, Matthew; Ha, Richard


    Many clinicians caring for patients with continuous flow left ventricular assist devices (CF-LVAD) use ramp right heart catheterization (RHC) studies to optimize pump speed and also to troubleshoot CF-LVAD malfunction. An investigational device, the ReliantHeart Heart Assist 5 (Houston, TX), provides the added benefit of an ultrasonic flow probe on the outflow graft that directly measures flow through the CF-LVAD. We performed a simultaneous ramp RHC and echocardiogram on a patient who received the above CF-LVAD to optimize pump parameters and investigate elevated flow through the CF-LVAD as measured by the flow probe. We found that the patient’s hemodynamics were optimized at their baseline pump speed, and that the measured cardiac output via the Fick principle was lower than that measured by the flow probe. Right heart catheterization may be useful to investigate discrepancies between flow measured by a CF-LVAD and a patient’s clinical presentation, particularly in investigational devices where little clinical experience exists. More data is needed to elucidate the correlation between the flow measured by an ultrasonic probe and cardiac output as measured by RHC. PMID:28163837

  5. Achieving Identity-Based Cryptography in a Personal Digital Assistant Device

    Directory of Open Access Journals (Sweden)

    L. Martínez-Ramos


    Full Text Available Continuous technological advances have allowed that mobile devices, such as Personal Digital Assistants (PDAs, can execute sophisticated applications that more often than not must be equipped with a layer of security that should include the confidentiality and the authentication services within its repertory. Nevertheless, when compared against front-end computing devices, most PDAs are still seen as constrained devices with limited processing and storage capabilities.In order to achieve Identity-Based Cryptography (IBC, which was an open problem proposed by Adi Shamir in 1984, Bonehand Franklin presented in Crypto 2001, a solution that uses bilinear pairings as its main building block. Since then, IBC hasbecome an active area of investigation where many efficient IBC security protocols are proposed year after year. In this paper,we present a cryptographic application that allows the secure exchange of documents from a Personal Digital Assistant (PDAthat is wirelessly connected to other nodes. The architecture of our application is inspired by the traditional PGP (Pretty GoodPrivacy email security protocol. Our application achieves identity-based authentication and confidentiality functionalities at the 80-bit security level through the usage of a cryptographic library that was coded in C++. Our library can perform basic primitives such as bilinear pairings defined over the binary field and the ternary field , as well as other required primitivesknown as map-to-point hash functions. We report the timings achieved by our application and we show that they compare wellagainst other similar works published in the open literature.

  6. Use of the Nippon-Zeon pneumatic ventricular assist device as a bridge to cardiac transplantation. (United States)

    Deleuze, P H; Le Besnerais, P; Mazzucotellu, J P; Abe, Y; Miyama, M; Mourtada, A; Benvenuti, C; Loisance, D Y


    The Nippon-Zeon (NZ) ventricular assist device is a sac type, air driven, heterotopic, external pump. Its performance has been evaluated in Japan as a bridge to myocardial recovery. Few data are available on the device as a bridge to heart transplantation. Since 1991, 10 patients (9 men) were bridged to heart transplantation with NZ, all in biventricular support. The mean age was 39 +/- 13 years (range, 21-60 years), mean body weight was 75 +/- 13 kg (range, 51-95 kg). Five patients had a dilated cardiopathy, and five were ischemic (three acute myocardial infarctions). Despite maximal inotropic support, including enoximone in seven, epinephrine in three, and intraaortic balloon pumping in one, eight patients were anuric, three were in acute hepatic failure, and three were intubated. Preoperative hemodynamic and biologic values were: cardiac index, 1.57 +/- 0.4 l/min/m2; pulmonary capillary wedge pressure, 34 +/- 5 mmHg; creatinine, 200 +/- 80 mumol/l; blood urea nitrogen, 17.5 +/- 8 mmol/l; total bilirubin 36 +/- 6 mumol/l; aspartate aminotransferase, 1,000 +/- 2,000 IU/l. In all patients, a biventricular assist device was implanted without the use of cardiopulmonary bypass. Improvement occurred immediately in all but one. Mean left ventricular flow was 4.5 +/- 0.8 l/min. Anticoagulation was maintained with intravenous heparin. Recently for bleeding was required in one case (10%), and two patients had positive blood cultures that were successfully treated. There was no mechanical failure. Hemolysis was not significant (lactate dehydrogenase, 378 +/- 50 IU/l; plasma-free hemoglobin below 10 mg/dl). Each device was free of thrombi and deposits at time of explantation. One patient died while on assist. Nine patients (90%) were transplanted after 11 +/- 8 days (range, 1-32 days). Three died early after transplantation, one of graft failure, two of sepsis. Six patients (66%) could be discharged. The follow-up ranges from 7 to 28 months. NZ is a simple, reliable

  7. Current status of percutaneous right ventricular assist devices: First-in-man use of a novel dual lumen cannula. (United States)

    Aggarwal, Vikas; Einhorn, Bryce N; Cohen, Howard A


    Ventricular assist devices have become an accepted therapeutic solution for patients with severe left ventricular dysfunction when pharmacology fails to maintain sufficient cardiac output. Despite various technologies that have allowed left ventricular assist devices to become more reliable and versatile in the past decade, comparatively little attention has been applied to right heart assistance which is still in the early stage of its development. The extracorporeal devices developed thus far have been associated with mobility issues and complications common to ventricular assist devices in general, such as infection, bleeding, and thromboembolism. Designed to obviate the problems previously experienced by other right ventricle (RV)-focused devices, the Protek Duo (CardiacAssist, Pittsburgh, PA) is a novel, fully percutaneous, dual lumen cannula for RV support used in conjunction with the paracorporeal TandemHeart(®) (CardiacAssist, Pittsburgh, PA) pump. We describe our initial experience with the Protek Duo cannula in two different clinical scenarios. In addition, we summarize the current percutaneous mechanical support technology for RV assistance and propose modification of current technology to facilitate its application. © 2016 Wiley Periodicals, Inc.

  8. The Role of Subjective Well-Being in Co-Designing Open-Design Assistive Devices; design case study

    NARCIS (Netherlands)

    De Couvreur, L.; Dejonghe, W.; Detand, J.; Goossens, R.


    In this paper we explore the role of subjective well-being within the process of making together a personalized assistive device. Through a process of social product adaptation, assistive artifacts become part of occupational therapy and co-evolve with clients. Personal digital fabrication tools ena

  9. Endoscopic Evaluation and Management of Gastrointestinal Bleeding in Patients with Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Marty M. Meyer


    Full Text Available The optimal diagnostic approach and yield for gastrointestinal bleeding (GIB in patients with ventricular assist devices (VAD are unknown. We explored the etiology of bleeding and yield of upper and lower endoscopy, balloon-assisted enteroscopy, and video capsule endoscopy in the evaluation of GIB in patients with VADs. Methods. All VAD patients with overt gastrointestinal bleeding and drop in hematocrit from April 1, 2000 to July 31, 2008 were retrospectively reviewed. The endoscopic evaluation of each episode was recorded. Overall yield of EGD, colonoscopy, balloon-assisted, and video capsule endoscopy were evaluated. Results. Thirty-six bleeding episodes occurred involving 20 patients. The site of GIB was identified in 32/36 episodes (88.9%, and the etiology of bleeding was determined in 30/36 cases (83.3%. Five VAD patients underwent VCE. The VCE exams demonstrated a high yield with 80% of exams identifying the etiology of GIB. Endoscopic intervention was successful in 8/9 attempts. No adverse events were recorded. Two patients required surgical intervention for GIB. Conclusion. Upper, lower, video capsule, and balloon-assisted enteroscopies are safe and demonstrate a high yield in the investigation of gastrointestinal bleeding in VAD patients. Medical centers caring for VAD patients should employ a standardized protocol to optimize endoscopic evaluation and intervention.

  10. Analysis of baroreflex sensitivity during undulation pump ventricular assist device support. (United States)

    Liu, Hongjian; Shiraishi, Yasuyuki; Zhang, Xiumin; Song, Hojin; Saijo, Yoshifumi; Baba, Atsushi; Yambe, Tomoyuki; Abe, Yusuke; Imachi, Kou


    The aim of this study was to examine the baroreflex sensitivity (BRS), which involves the autonomic nervous system, in a goat with a chronically implanted undulation pump ventricular assist device (UPVAD). The UPVAD involved transforming the rotation of a brushless DC motor into an undulating motion by a disc attached via a special linking mechanism, and a jellyfish valve in the outflow cannula to prevent diastolic backflow. The pump was implanted into the thoracic cavity of a goat by a left thoracotomy, and the inflow and outflow cannulae were sutured to the apex of the left ventricle and to the descending aorta, respectively. The driving cable was wired percutaneously to an external controller. Electrocardiogram and hemodynamic waveforms were recorded at a sampling frequency of 1 kHz. BRS was determined when awake by the slope of the linear regression of R-R interval against mean arterial pressure changes, which were induced by the administration of methoxamine hydrochloride, both with continuous driving of the UPVAD as well as without assistance. BRS values during the UPVAD support and without assistance were 1.60 +/- 0.30 msec/mm Hg and 0.98 +/- 0.22 msec/mm Hg (n = 5, P < 0.05), respectively. BRS was significantly improved during left ventricular assistance. Therefore, UPVAD support might decrease sympathetic nerve activity and increase parasympathetic nerve activity to improve both microcirculation and organ function.

  11. A programmable and portable NMES device for drop foot correction and blood flow assist applications. (United States)

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


    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.

  12. Evolvement of left ventricular assist device: the implications on heart failure management. (United States)

    Chair, Sek Ying; Yu, Doris Sf; Ng, Michael Timothy; Wang, Qun; Cheng, Ho Yu; Wong, Eliza Ml; Sit, Janet Wh


    Heart failure (HF) is a potentially fatal disease that affects increasing number of people worldwide. Although heart transplant is the "gold standard" therapy for HF, due to the limited availability of organs, many patients died when waiting for the transplant. Left ventricular assist device (LVAD), as a mechanical circulatory support, has become a new light for patients with HF. With the technical advancements, LVADs work not only as a bridge to transplant, but also assist heart recovery and even as a destination therapy in long-term treatment. This observation paper reviewed the development of LVAD and its clinical roles. The challenges and possible solutions in nursing care for patients with LVAD at different stage of implantation were discussed. The healthcare professionals could obtain a better understanding about the LVAD treatment for HF patients.

  13. Renal Replacement Therapy in Congestive Heart Failure Requiring Left Ventricular Assist Device Augmentation


    Thomas, Bernadette A.; Logar, Christine M.; Anderson, Arthur E.


    “Cardiorenal syndrome” is a term used to describe a dys-regulation of the heart affecting the kidneys, or vice versa, in an acute or chronic manner (1,2). Renal impairment can range from reversible ischemic damage to renal failure requiring short- or long-term renal replacement therapy (2). Patients who require mechanical circulatory support, such as a left ventricular assist device (LVAD), as definitive treatment for congestive heart failure or as a bridge to cardiac transplantation pose a u...

  14. Sleep-disordered breathing in heart failure patients after ventricular assist device implantation and heart transplantation. (United States)

    Chowdhury, Anindita; Mathew, Reeba; Castriotta, Richard J


    Chronic heart failure (CHF) represents a major health and economic burden and is associated with high rates of hospital admission, morbidity, mortality and decreased quality-adjusted life years. New advances in the treatment of CHF such as ventricular assist devices (VADs) and heart transplantation have helped improve outcomes. Sleep-disordered breathing (SDB) is highly prevalent in CHF patients and the associated morbidity makes it essential for physicians to be more cognizant about its existence, interaction and need for treatment. This is a review of what is known to date about SDB in CHF patients who have undergone advanced treatments with VADs and/or heart transplantation.

  15. Repair of pectus excavatum during HeartMate II left ventricular assist device placement. (United States)

    Tchantchaleishvili, Vakhtang; Massey, Howard Todd


    Pectus excavatum deformity often remains clinically asymptomatic even in cases of a severely diminished thoracic volume and frequently remains uncorrected. In the patient population that requires left ventricular assist device (LVAD) placement, a diminished thoracic volume can be problematic and lead to significant challenges in pump and outflow cannula positioning. Here we present a case of pectus excavatum correction during LVAD placement to show that this deformity can be successfully addressed with minimal, if any, additional operative risk at the time of LVAD implant.

  16. Powered orthosis and attachable power-assist device with Hydraulic Bilateral Servo System. (United States)

    Ohnishi, Kengo; Saito, Yukio; Oshima, Toru; Higashihara, Takanori


    This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb powered orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions.

  17. Exercise in heart failure patients supported with a left ventricular assist device

    DEFF Research Database (Denmark)

    Jung, Mette Holme; Gustafsson, Finn


    After implantation of a continuous-flow left ventricular assist device (CF-LVAD), exercise capacity in heart failure patients remains reduced with peak oxygen uptake (peak VO2) values averaging from 11 to 20 ml/kg/min. Total cardiac output in CF-LVAD patients during exercise is predominantly...... determined by pump speed, the pressure difference across the pump, and in some cases ejection through the aortic valve. Fixed pump speed utilized in CF-LVADs may provide insufficient support, resulting in a moderate cardiac output increase during increased physical strain. Ongoing studies are evaluating...... whether pump speed changes in response to varied loading conditions may enable LVADs to provide sufficient support even during strenuous exercise. In the currently used devices, evidence suggests that focus on optimizing non-cardiac peripheral parameters is vital. Extra-cardiac potentially reversible...

  18. The Impact of Ventricular Assist Device Prior to Transplantation on Morphological Parameters in Cardiac Allografts

    DEFF Research Database (Denmark)

    Wassilew, Katharina


    Due to the shortage of donor organs, mechanical circulatory support systems (MCS) are now widely used as a treatment option to bridge the failing heart to transplantation. There are limited data, suggesting that prolonged use of ventricular assist device (VAD) therapy may result in cardiac...... of the level of macrophages on the degree of IF in right ventricular endomyocardial biopsies (EMBs) of cardiac allografts. Methods: We evaluated all consecutive EMBs of cardiac allografts from 254 patients taken between 01/2011 and 12/2012.With regard to pre-transplant MCS treatment, patients were divided...... into two groups (MCS group n=82 patients, non-MCS group n=138 patients). The MCS patients were subdivided into groups regarding the device used (HeartMate II, HeartWare, Novacor, Incor, Excor). Patients were excluded from the analysis if they had an MCS system that was used in fewer than five of the study...

  19. Low-cost assistive device for hand gesture recognition using sEMG (United States)

    Kainz, Ondrej; Cymbalák, Dávid; Kardoš, Slavomír.; Fecil'ak, Peter; Jakab, František


    In this paper a low-cost solution for surface EMG (sEMG) signal retrieval is presented. The principal goal is to enable reading the temporal parameters of muscles activity by a computer device, with its further processing. Paper integrates design and deployment of surface electrodes and amplifier following the prior researches. Bearing in mind the goal of creating low-cost solution, the Arduino micro-controller was utilized for analog-to-digital conversion and communication. The software part of the system employs support vector machine (SVM) to classify the EMG signal, as acquired from sensors. Accuracy of the proposed solution achieves over 90 percent for six hand movements. Proposed solution is to be tested as an assistive device for several cases, involving people with motor disabilities and amputees.

  20. Leg muscle activity during walking with assistive devices at varying levels of weight bearing. (United States)

    Clark, Brian C; Manini, Todd M; Ordway, Nathaniel R; Ploutz-Snyder, Lori L


    To evaluate the muscle activation patterns at varying levels of weight-bearing forces during assisted walking with an axillary crutch and a recently designed device that allows weight transfer through the pelvic girdle (ED Walker). Descriptive, repeated measures. University-based research laboratory. Twelve healthy volunteers (age, 39.6+/-13.6 y). Not applicable. Electromyographic activity was recorded from the anterior tibialis, soleus, biceps femoris, and vastus lateralis muscles on a test leg during assisted axillary crutch and ED Walker ambulation. Force platform readings measured weight-bearing load (non, light, heavy). These values were normalized to normal walking gait. In the vastus lateralis and soleus muscles, both devices allowed for approximately 50% and 65% reductions in electromyographic activity during the non-weight-bearing condition. During crutch ambulation, electromyographic activity of the soleus was significantly reduced compared with that required for normal walking at all levels of weight-bearing load. In the vastus lateralis for the weight-bearing conditions, the ED Walker required significantly higher electromyographic activity than crutch ambulation (light: 105.0%+/-12.3% vs 72.7%+/-10.1%; heavy: 144.8%+/-23.5% vs 100.0%+/-13.5%). Both devices required similar peak vertical ground reaction forces during the heavy weight-bearing conditions (crutch: 75%+/-1.6%; ED Walker: 73%+/-1.8%), whereas axillary crutch gait produced less force than the ED Walker in the light condition (32%+/-2.0% vs 48%+/-1.6%). During walking with assistive devices, muscle activation patterns varied with weight-bearing load. The leg extensor muscles appeared to incur a greater reduction in muscle activity when compared with their flexor counterparts. Additionally, the ED Walker and axillary crutch differed with respect to their muscle activity levels and weight-bearing characteristics. Clinically, knowledge of these muscle activity and force characteristics may aid in

  1. Thrombosis in continuous-flow left ventricular assist devices: pathophysiology, prevention, and pharmacologic management. (United States)

    Jennings, Douglas L; Weeks, Phillip A


    Continuous-flow left ventricular assist devices reduce short-term mortality and improve quality of life in patients with end-stage heart failure. Unfortunately, device-related complications remain common, with many patients experiencing adverse events within the first year. New literature suggests that rates of device-related thrombosis may be increasing since 2011, which is particularly troublesome given that this pathology can result in a disabling stroke, organ damage, and death. In 2013, a group of practitioners in the field of mechanical circulatory support published a treatment algorithm based on their expert opinion. However, a comprehensive review of the pharmacotherapy of this condition is lacking. A search of the literature revealed 20 separate publications of case reports or case series describing outcomes associated with the use of drug therapy for suspected pump thrombosis. Each of these experiences was limited by small sample size, nonrandomized treatment allocation, and nonstandardized medication dosing. Data describing the outcomes of surgical versus medical management of device thrombosis are also sparse, with only three published reports identified. Based on the review of this limited literature, surgical management appears to be the preferred treatment modality, especially in those with organ hypoperfusion or hemodynamic instability. In patients ineligible for surgery, pharmacotherapy options remain limited. Use of all drug classes described in the literature for the HeartMate II device-fibrinolytics, glycoprotein IIb/IIIa inhibitors, and direct thrombin inhibitors-was hindered by either marginal efficacy or bleeding. Based on historical experience with unfractionated heparin in patients under HeartMate II support, we recommend this agent as a possible option for those with suspected pump thrombosis in lieu of surgical device exchange. For the HeartWare HVAD, limited data suggest that direct intraventricular administration of alteplase may be an

  2. Phantom-based evaluation method for surgical assistance devices in minimally invasive cochlear implantation (United States)

    Lexow, G. Jakob; Kluge, Marcel; Majdani, Omid; Lenarz, Thomas; Rau, Thomas S.


    Several research groups have proposed individual solutions for surgical assistance devices to perform minimally invasive cochlear implantation. The main challenge is the drilling of a small bore hole from the surface of the skull to the inner ear at submillimetric accuracy. Each group tested the accuracy of their device in their respective test bench or in a small number of temporal bone specimens. This complicates the comparison of the different approaches. Thus, a simple and inexpensive phantom based evaluation method is proposed which resembles clinical conditions. The method is based on half-skull phantoms made of bone-substitute material - optionally equipped with an artificial skin replica to include skin incision within the evaluation procedure. Anatomical structures of the temporal bone derived from segmentations using clinical imaging data are registered into a computer tomographic scan of the skull phantom and used for the planning of the drill trajectory. Drilling is performed with the respective device under conditions close to the intraoperative setting. Evaluation of accuracy can either be performed through postoperative imaging or by means of added targets on the inside of the skull model. Two different targets are proposed: simple reference marks only for measuring the accuracy of the device and a target containing a scala tympani model for evaluation of the complete workflow including the insertion of the electrode carrier. Experiments using the presented method take place under reproducible conditions thus allowing the comparison of the different approaches. In addition, artificial phantoms are easier to obtain and handle than human specimens.

  3. Fine-tuning management of the Heart Assist 5 left ventricular assist device with two- and three-dimensional echocardiography (United States)

    Demirozu, Zumrut Tuba; Kucukaksu, Deniz Suha; Arat, Nurcan


    Summary Introduction: Left ventricular assist device (LVAD) implantation is a viable therapy for patients with severe end-stage heart failure, providing effective haemodynamic support and improved quality of life. The Heart Assist 5 (Micromed Cardiovascular Inc, Houston, TX) continuous-flow LVAD has been on the market in Europe since May 2009. Methods: We evaluated nine Heart Assist 5 LVAD patients with two- and three-dimensional transthoracic echocardiographic (TTE) and transoesophageal echocardiographic (TEE) parameters between December 2011 and December 2013. The pre-operative TTE LVAD evaluations included left ventricular (LV) function and structure, quantification of right ventricular (RV) function and tricuspid regurgitation (TR), assessment of aortic and mitral regurgitation, and presence of patent foramen ovale and intra-cardiac clots. Peri-operative TEE determined the inflow cannula and septum position, and assessed the de-airing process while weaning from cardiopulmonary bypass. Post-operative serial follow-up TTE showed the surgical results of LVAD implantation, determined the overall structure and function of the LV, RV and TR, and observed the inflow and outflow cannula position. Results: Nine patients who had undergone Heart Assist 5 LVAD implantation and had been followed up for more than 30 days were included in this study. Eight patients had ischaemic cardiomyopathy and one had adriamycin-induced cardiomyopathy. Pre-implantation data: the mean age of the patients was 52 ± 13 (34–64) years, mean body surface area (BSA) was 1.8 ± 0.2 (1.6–2.0) m2, mean cardiac index (CI) was 2.04 ± 0.4 (1.5–2.6) l/min/m2, mean cardiac output (CO) was 3.7 ± 0.7 (2.6–4.2) l/min, mean ejection fraction (EF) was 23 ± 5 (18–28)%, and right ventricular fractional area contraction (RVFAC) was 43 ± 9 (35–55)%. One patient had aortic valve replacement (AVR) during the LVAD implantation, and excess current alarms and increased power were suspected to be

  4. Management of three cardiogenic pulmonary edemas occurring in a patient scheduled for left ventricular assist device implantation: indicators for determining left ventricular assist device pump speed. (United States)

    Toyama, Hiroaki; Takei, Yusuke; Saito, Kazutomo; Ota, Takahisa; Kurotaki, Kenji; Ejima, Yutaka; Matsuura, Takeshi; Akiyama, Masatoshi; Saiki, Yoshikatsu; Yamauchi, Masanori


    A male patient with Marfan syndrome underwent aortic root replacement and developed left ventricular (LV) failure. Four years later, he underwent aortic arch and aortic valve replacement. Thereafter, his LV failure progressed, and cardiogenic pulmonary edema (CPE) appeared, which we treated with extracorporeal LV assist device (LVAD) placement. Three months later, the patient developed aspiration pneumonia, which caused hyperdynamic right ventricle (RV) and CPE. We treated by changing his pneumatic LVAD to a high-flow centrifugal pump. A month later, he underwent thoracoabdominal aortic replacement. After four weeks, he developed septic thrombosis and LVAD failure, which caused CPE. We treated with LVAD circuit replacement and an additional membrane oxygenator. Four months later, he underwent DuraHeart(®) implantation. During this course, pulmonary artery wedge pressure (PAWP) varied markedly. Additionally, systolic pulmonary artery pressure (sPAP), left atrial diameter (LAD), RV end-diastolic diameter (RVEDD) and estimated RV systolic pressure (esRVP) changed with PAWP changes. In this patient, LV failure and hyperdynamic RV caused the CPEs, which we treated by adjusting the LVAD output to the RV output. Determining LVAD output, RV function and LV end-diastolic diameter are typically referred, and PAWP, LAD, RVEDD, and sPAP could be also referred.

  5. Ventricular assist devices in heart failure: how to support the heart but prevent atrophy? (United States)

    Pokorný, M; Cervenka, L; Netuka, I; Pirk, J; Koňařík, M; Malý, J


    Ventricular assist devices (VAD) have recently established themselves as an irreplaceable therapeutic modality of terminal heart failure. Because of the worldwide shortage of donors, ventricular assist devices play a key role in modern heart failure therapy. Some clinical data have revealed the possibility of cardiac recovery during VAD application. On the other hand, both clinical and experimental studies indicate the risk of the cardiac atrophy development, especially after prolonged mechanical unloading. Little is known about the specific mechanisms governing the unloading-induced cardiac atrophy and about the exact ultrastructural changes in cardiomyocytes, and even less is known about the ways in which possible therapeutical interventions may affect heart atrophy. One aim of this review was to present important aspects of the development of VAD-related cardiac atrophy in humans and we also review the most significant observations linking clinical data and those derived from studies using experimental models. The focus of this article was to review current methods applied to alleviate cardiac atrophy which follows mechanical unloading of the heart. Out of many pharmacological agents studied, only the selective beta2 agonist clenbuterol has been proved to have a significantly beneficial effect on unloading-induced atrophy. Mechanical means of atrophy alleviation also seem to be effective and promising.

  6. Haptic cue control of an MR gear shifting assistance device via Preisach hysteresis linearization (United States)

    Han, Young-Min; Choi, Seung-Bok; Chung, Jye Ung; Kim, Soomin


    This paper proposes a driver assistance device to notify vehicle drivers an optimal gear shifting timing considering fuel consumption in manual transmission vehicles. The haptic cue function of the proposed gear shifting assistance device is utilizing magnetorheological (MR) clutch mechanism as haptic interface between driver and vehicle. The shear stress level and hysteretic behavior of the employed MR fluid are experimentally observed and identified with the Preisach model. A rotary type clutch mechanism is designed and manufactured with electromagnetic circuit and its transmission torque level is experimentally evaluated according to the applied current. The manufactured MR clutch is integrated with accelerator pedal on which driver's foot is placed to transmit haptic cue signal. In the meantime, a cue algorithm for gear shifting is formulated by considering vehicle model. The cue algorithm is then integrated with a haptic controller which is a torque model based-compensation strategy regarding Presiach hystersis linearization of the employed MR fluid. In this work, the haptic cue controller is implemented in discrete manner. Control performances are experimentally evaluated such as haptic tracking responses.

  7. Communicating with assistive listening devices and age-related hearing loss: Perceptions of older Australians. (United States)

    Aberdeen, Lucinda; Fereiro, David


    Abstract Age-related hearing loss can impact adversely on the delivery of primary care and cannot necessarily be remedied by hearing aid technology. A study of 20 older Australians living in a Queensland retirement village and residential hostel complex was undertaken to investigate how communication might be advanced through an assistive listening device (ALD). Most participants were women aged over 85 years; almost all had hearing loss and wore hearing aids. Tests with an ALD found very high levels of satisfaction with understanding speech and sound quality amongst participants. However, few had heard previously of ALDs, all required individualised assistance to fit and use the device and rated ease of use less highly. The findings affirm those of previous studies that ALD technology has a role in communication for older hearing impaired people and for hearing rehabilitation. Its potential to enhance quality of life can be facilitated and promoted through nursing practice, but requires professional and consumer education so that it is not overlooked as a communication option.

  8. Extracorporeal Life Support Bridge to Ventricular Assist Device: The Double Bridge Strategy. (United States)

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


    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.

  9. Validity of 2 devices for measuring steps taken by older adults in assisted-living facilities. (United States)

    Bergman, Randall J; Bassett, David R; Muthukrishnan, Suresh; Klein, Diane A


    This 2-part study examined validity of selected motion sensors for assessing physical activity in older adults residing in assisted-living communities. Twenty-one older adults (mean age = 78.6 +/- 13.1 years) wore the StepWatch 3 Step Activity Monitor (SW3) and the Yamax Digi-Walker SW-200 pedometer (DW). Part I compared accuracy of these devices for measuring steps taken over 161 m. Part II compared devices over a 1-day (24-hour) period. In part I, the DW recorded 51.9% (r2 = -.08, P = .75) and the SW3 recorded 102.6% (r2 = .99, P < .001) of steps. In part II, the DW measured significantly fewer steps (1587 +/- 1057 steps) than did the SW3 (6420 +/- 3180 steps). The SW3 pedometer was more accurate in counting steps and recorded higher 24-hour step counts than the DW pedometer. Thus, the SW3 is a valid research instrument for monitoring activity in the assisted-living population.

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

    Directory of Open Access Journals (Sweden)

    Carolina Bastos Plotegher


    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.

  11. Gastrointestinal bleeding in a patient with a continuous-flow biventricular assist device

    Institute of Scientific and Technical Information of China (English)

    Raymond V Mirasol; Jason J Tholany; Hasini Reddy; Billie S Fyfe-Kirschner; Christina L Cheng; Issam F Moubarak; John L Nosher


    The association between continuous-flow left ventricular assist devices(CF-LVADs)and gastrointestinal(GI)bleeding from angiodysplasia is well recognized.However,the association between continuous-flow biventricular assist devices(CF-BIVADs)and bleeding angiodysplasia is less understood.We report a case of GI bleeding from a patient with a CF-BIVAD.The location of GI bleeding was identified by nuclear red blood cell bleeding scan.The vascular malformation leading to the bleed was identified and localized on angiography and then by pathology.The intensity of bleeding,reflected by number of units of packed red blood cells needed for normalization of hemoglobin,as well as the time to onset of bleeding after transplantation,are similar to that seen in the literature for CF-LVADs and pulsatile BIVADs.While angiography only detected a dilated late draining vein,pathology demonstrated the presence of both arterial and venous dilation in the submucosa,vascular abnormalities characteristic of a late arteriovenous malformation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Politti, Julio C; Puglisi, Lisandro J; Farfan, Fernando D [Departamento de BioingenierIa - FaCEyT - UNT (Argentina)


    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{sup 0}, 20{sup 0}, 40{sup 0} and 60{sup 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.

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

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


    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.

  14. Regaining Candidacy for Heart Transplantation after Robotic Assisted Laparoscopic Radical Prostatectomy in Left Ventricular Assist Device Patient

    Directory of Open Access Journals (Sweden)

    Tariq A. Khemees


    Full Text Available Several factors may highlight the relevance of prostate cancer to the pre-heart-transplant population. First, the expansion in candidate selection criteria led to increased number of men over the age of fifty to be considered for heart transplantation. With the introduction of left ventricular assist device (LVAD therapy, waiting-list mortality has dramatically declined over the past decade. Additionally, transplant candidates are diligently screened for preexisting neoplasm while on the waiting list. Taken together, screening-detected prostate cancer may increasingly be diagnosed in patients on the waiting list. If discovered, it will pose unique challenge to clinicians as to date there has been no universally accepted management guideline. We report a case of LVAD-treated heart transplant candidate diagnosed with prostate cancer while on the waiting list. Patient screening demonstrated PSA elevation which prompted prostate biopsy. Low-risk clinically localized prostate cancer was confirmed and led to removal of patient from transplant list. When counseled regarding management of his cancer, the patient elected to undergo radical prostatectomy in a hope to regain candidacy for heart transplantation. Despite being of high surgical risk, multidisciplinary team approach led to successful management of prostate cancer and the patient eventually received heart transplant one year following prostatectomy.

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

    Directory of Open Access Journals (Sweden)

    Yu Jin Park


    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.

  16. Electric poling-assisted additive manufacturing process for PVDF polymer-based piezoelectric device applications (United States)

    Lee, ChaBum; Tarbutton, Joshua A.


    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.

  17. Prediction of survival in patients with cardiogenic shock and multiorgan failure treated with biventricular assist device. (United States)

    Potapov, Evgenij V; Stepanenko, Alexander; Kukucka, Marian; Ba Fadhl, Faiz H; Qedra, Naser; Weng, Yuguo; Pasic, Miralem; Lehmkuhl, Hans B; Krabatsch, Thomas; Hetzer, Roland


    Mechanical circulatory support (MCS) is valuable in saving the lives of patients with severe cardiogenic shock. However, their survival is limited if multiorgan failure (MOF) proves to be irreversible. Although ventricular assist devices (VADs) have been shown to reverse end-organ failure in some patients, the pathophysiological mechanisms of end-organ failure and its regression are not fully understood, and clinical markers and thresholds for the "point of no return" are lacking. We investigated predictors of 30-day survival in patients supported with a biventricular assist device (BVAD). We studied 157 patients implanted with a Berlin Heart EXCOR BVAD between 1987 and 2006. Children younger than 10 years and cases with postcardiotomy syndrome and transplant failure were excluded from the analysis as well as patients with technical or bleeding problems requiring rethoracotomy. In total, 69 clinical, hemodynamic, echocardiographic, and laboratory parameters were evaluated. Most of the patients suffered from ischemic cardiomyopathy or acute myocardial infarction. In addition, the preoperative multiple organ dysfunction syndrome (MODS) and the sequential organ failure assessment (SOFA) scores were calculated. The patients were divided into two groups regarding procedural success: group I-survival >30 days or heart transplantation or weaning from device (n = 105) and group II-death on system shock and MOF do not predict survival on BVAD. As expected, older patients are at higher risk for death on BVAD. Acidosis and high MODS score predict unfavorable outcome. However, the prediction of clinical outcome in patients in severe cardiogenic shock supported by BVAD is possible in extreme situations only.

  18. In Vivo Evaluation of a Pneumatic Extracorporeal Ventricular Assist Device for up to 90 Day Support. (United States)

    Conger, Jeff L; Grace, Brian W; Van Noy, Kelsey L; Handy, Kelly M; Costas, Gil G; Rodriguez-Sierra, Carlos A; Trejo, Alejandro; Pinzon, Javier; Cohn, William E

    In a previous study, we showed that the Vitalmex Extracorporeal Ventricular Assist Device-Pneumatic (EVAD-P)-a low-cost, pneumatically actuated, pulsatile blood pump-is easy to implant and safe for short-term in vivo support (30 ± 5 days). In the current study, we included additional 30 day experiments and assessed the safety and durability of the EVAD-P for up to 90 days of support. Using the same surgical procedure as in the previous study, we implanted the device into 14 healthy sheep. Group I subjects (n = 7) were evaluated for up to 30 days, and group II (n = 2) and group III (n = 5) subjects were evaluated for up to 49 and 93 days, respectively. After a system redesign, two of the five sheep in group III reached the scheduled end-point without device-related problems at a fixed beat rate of 56 bpm, a stroke volume (SV) of 58.0 ± 2.3 ml, and a flow of 3.5 ± 0.2 L/min. This study shows that the EVAD-P can provide safe pulsatile mechanical circulatory support (MCS) for up to 93 days. To further confirm that the system can consistently provide MCS for this duration, additional studies are recommended.

  19. Hybrid stent device of flow-diverting effect and stent-assisted coil embolization formed by fractal structure. (United States)

    Kojima, Masahiro; Irie, Keiko; Masunaga, Kouhei; Sakai, Yasuhiko; Nakajima, Masahiro; Takeuchi, Masaru; Fukuda, Toshio; Arai, Fumihito; Negoro, Makoto


    This paper presents a novel hybrid medical stent device. This hybrid stent device formed by fractal mesh structures provides a flow-diverting effect and stent-assisted coil embolization. Flow-diverter stents decrease blood flow into an aneurysm to prevent its rupture. In general, the mesh size of a flow-diverter stent needs to be small enough to prevent blood flow into the aneurysm. Conventional flow-diverter stents are not available for stent-assisted coil embolization, which is an effective method for aneurysm occlusion, because the mesh size is too small to insert a micro-catheter for coil embolization. The proposed hybrid stent device is capable of stent-assisted coil embolization while simultaneously providing a flow-diverting effect. The fractal stent device is composed of mesh structures with fine and rough mesh areas. The rough mesh area can be used to insert a micro-catheter for stent-assisted coil embolization. Flow-diverting effects of two fractal stent designs were composed to three commercially available stent designs. Flow-diverting effects were analyzed using computational fluid dynamics (CFD) analysis and particle image velocimetry (PIV) experiment. Based on the CFD and PIV results, the fractal stent devices reduce the flow velocity inside an aneurism just as much as the commercially available flow-diverting stents while allowing stent-assisted coil embolization.

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

    Institute of Scientific and Technical Information of China (English)

    Jia Ke; Shao-Xing Zhang; Lei Hu; Chang-Sheng Li; Yun-Feng Zhu; Shi-Long Sun; Li-Feng Wang


    Background:A single drilled tunnel from the lateral mastoid cortex to the cochlea via the facial recess is essential for minimally invasive cochlear implant surgery.This study aimed to explore the safety profile of this kind of new image-guided and bi-planar device-assisted surgery procedure in vitro.Methods:Image-guided minimally invasive cochlear implantations were performed on eight cadaveric temporal bone specimens.The main procedures were:(1) temporal bone specimens were prepared for surgery and fiducial markers were registered.(2) computed tomography (CT) scans were performed for future reference.(3) CT scan images were processed and drill path was planned to minimize cochlear damage.(4) bi-planar device-assisted drilling was performed on the specimens using the registration.(5) surgical safety was evaluated by calculating the deviation between the drill and the planned paths,and by measuring the closest distance between the drilled path and critical anatomic structures.Results:Eight cases were operated successfully to the basal turn of the cochlear with intact facial nerves (FNs).The deviations from target points and entrance points were 0.86 mm (0.68-1.00 mm) and 0.44 mm (0.30-0.96 mm),respectively.The angular error between the planned and the drilled trajectory was 1.74° (1.26-2.41°).The mean distance from the edge of the drilled path to the FN and to the external canal was 0.60 mm (0.35-0.83 mm) and 1.60 mm (1.30-2.05 mm),respectively.In five specimens,the chorda tympani nerves were well preserved.In all cases,no injury happened to auditory ossicles.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.

  1. Minimally Invasive Cochlear Implantation Assisted by Bi-planar Device: An Exploratory Feasibility Study in vitro (United States)

    Ke, Jia; Zhang, Shao-Xing; Hu, Lei; Li, Chang-Sheng; Zhu, Yun-Feng; Sun, Shi-Long; Wang, Li-Feng; Ma, Fu-Rong


    Background: A single drilled tunnel from the lateral mastoid cortex to the cochlea via the facial recess is essential for minimally invasive cochlear implant surgery. This study aimed to explore the safety profile of this kind of new image-guided and bi-planar device-assisted surgery procedure in vitro. Methods: Image-guided minimally invasive cochlear implantations were performed on eight cadaveric temporal bone specimens. The main procedures were: (1) temporal bone specimens were prepared for surgery and fiducial markers were registered. (2) computed tomography (CT) scans were performed for future reference. (3) CT scan images were processed and drill path was planned to minimize cochlear damage. (4) bi-planar device-assisted drilling was performed on the specimens using the registration. (5) surgical safety was evaluated by calculating the deviation between the drill and the planned paths, and by measuring the closest distance between the drilled path and critical anatomic structures. Results: Eight cases were operated successfully to the basal turn of the cochlear with intact facial nerves (FNs). The deviations from target points and entrance points were 0.86 mm (0.68–1.00 mm) and 0.44 mm (0.30–0.96 mm), respectively. The angular error between the planned and the drilled trajectory was 1.74° (1.26–2.41°). The mean distance from the edge of the drilled path to the FN and to the external canal was 0.60 mm (0.35–0.83 mm) and 1.60 mm (1.30–2.05 mm), respectively. In five specimens, the chorda tympani nerves were well preserved. In all cases, no injury happened to auditory ossicles. 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. PMID:27748341

  2. 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: [Advanced Technologies and Regenerative Medicine, Somerville, NJ (United States)


    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.

  3. 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


    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.

  4. Falls and Use of Assistive Devices in Stroke Patients with Hemiparesis: Association with Balance Ability and Fall Efficacy. (United States)

    Kim, Oksoo; Kim, Jung-Hee


    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.

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

    Directory of Open Access Journals (Sweden)

    Shawna J. Lee


    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.

  6. Multifactorial assistive device intervention to prevent low back pain among caregivers

    DEFF Research Database (Denmark)

    Jensen, Stina Bjørnskov; Brandt, Åse


    Caregivers are among those professionals who experience the highest incidence of low back pain and low back injuries, and one of the most frequently described reasons for this is person transfers. This paper reports on a controlled intervention study in two Danish municipalities with perceived...... strain during person transfer, self reported low back pain and low back injuries as main outcomes. The intervention was implemented in one municipality consisting of maximum use of assistive devices for person transfer combined with organizational changes. The other municipality served as control group....... The study population consisted of all permanently employed caregivers in the two municipalities, and data was collected by means of a questionnaire at baseline and after 10 months of follow-up. At follow-up the caregivers in the intervention group reported lower perceived strain during person transfer...

  7. In Vitro Durability - Pivot bearing with Diamond Like Carbon for Ventricular Assist Devices

    CERN Document Server

    de Sá, Rosa Corrêa Leoncio; Leão, Tarcísio Fernandes; da Silva, Evandro Drigo; da Fonseca, Jeison Willian Gomes; da Silva, Bruno Utiyama; Leal, Edir Branzoni; Moro, João Roberto; de Andrade, Aron José Pazin; Bock, Eduardo Guy Perpétuo


    Institute Dante Pazzanese of Cardiology (IDPC) develops Ventricular Assist Devices (VAD) that can stabilize the hemodynamics of patients with severe heart failure before, during and/or after the medical practice; can be temporary or permanent. The ADV's centrifugal basically consist of a rotor suspended for system pivoting bearing; the PIVOT is the axis with movement of rotational and the bearing is the bearing surface. As a whole system of an implantable VAD should be made of long-life biomaterial so that there is no degradation or deformation during application time; surface modification techniques have been widely studied and implemented to improve properties such as biocompatibility and durability of applicable materials. The Chemical Vapour Deposition technique allows substrates having melting point higher than 300 {\\deg}C to be coated, encapsulated, with a diamond like carbon film (DLC); The test simulated the actual conditions in which the system of support remains while applying a ADV. The results hav...

  8. The Impact of Ventricular Assist Device Prior to Transplantation on Morphological Parameters in Cardiac Allografts

    DEFF Research Database (Denmark)

    Wassilew, Katharina


    Due to the shortage of donor organs, mechanical circulatory support systems (MCS) are now widely used as a treatment option to bridge the failing heart to transplantation. There are limited data, suggesting that prolonged use of ventricular assist device (VAD) therapy may result in cardiac...... of the level of macrophages on the degree of IF in right ventricular endomyocardial biopsies (EMBs) of cardiac allografts. Methods: We evaluated all consecutive EMBs of cardiac allografts from 254 patients taken between 01/2011 and 12/2012.With regard to pre-transplant MCS treatment, patients were divided....... The Cochran-Mantel-Haenzsel test was applied to assess significance of the differences in interactions between groups. To evaluate the impact of bridge- to- transplant mechanical circulatory support on development on transplant vasculopathy in cardiac allografts, the intramyocardial terminal arterial network...


    Directory of Open Access Journals (Sweden)

    Yu-Ju Lan


    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.

  10. Thermal assisted ion shrinkage (TAIS) of fluorinated polyimide for optical telecommunication devices (United States)

    Trigaud, T.; Moliton, J. P.; Quillat, M.; Chiron, D.


    In the framework of the development of low cost optical devices for telecommunications, here is studied the shrinkage of 6FDA-ODA polyimide films by ion irradiation as a function of five parameters: the ion fluence, the ion fluence rate, the ion energy, the ion nature and the target temperature. In the 30-350 keV energy range for impinging ions, the shrinkage remains constant whatever the tested fluence rate is. An upper limit appears for fluences above 10 16 ions cm -2. The etching is linearly dependent on the ion beam energy and reaches a maximum around 1 μm by thermal assisted ion shrinkage (TAIS) with Na + irradiations.

  11. Cardiogenic shock associated with loco-regional anesthesia rescued with left ventricular assist device implantation

    Directory of Open Access Journals (Sweden)

    Droogan Christopher


    Full Text Available Abstract A healthy 53 year old man developed profound cardiogenic shock following instillation of bupivacaine-lidocaine-epinephrine solution as a locoregional anesthetic for elective outpatient shoulder surgery. Intubation, resuscitation, and transfer to the nearby hospital were done: echocardiography showed profound biventricular dysfunction; cardiac catheterization showed normal coronary arteries. Despite placement of an intra-aortic balloon pump and intravenous vasoactive drugs, the patient remained in shock. Stabilization was achieved with emergent institution of cardiopulmonary bypass and placement of a temporary left ventricular assist device (LVAD. Twenty-four hours later, cardiac function normalized and the LVAD was removed. The patient was discharged five days later and remained with normal heart function in three-year follow-up.

  12. Disseminated Mycobacterium avium complex disease in a patient with left ventricular assist device (Heart Mate II). (United States)

    Cordioli, Maddalena; Del Bravo, Paola; Rigo, Fabio; Azzini, Anna Maria; Merighi, Mara; Forni, Alberto; Concia, Ercole


    Although disseminated Mycobacterium avium complex disease occurs mainly in immunocompromised hosts, especially HIV-infected patients in the last stage of the disease (AIDS), this condition is still rare in immunocompetent subjects. We report the case of a Caucasian man who received a left ventricular assist device two years before as a bridge to heart transplantation, that began to present signs and symptoms of mycobacterial infection. The diagnostic work-up we performed showed the presence of Mycobacterium intracellulare in lungs and both peripherical and bone marrow blood. Although evaluated, we found no abnormalities in the patient's immune system that can be related to mycobacterial infection. The beginning of a specific therapy made the patient slowly improve and further nuclear medicine assay (PET-TC) showed a good reduction in radio-labelled drug captation.

  13. Exercise physiology, testing, and training in patients supported by a left ventricular assist device. (United States)

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


    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.

  14. Simulation based efficiency prediction of a Brushless DC drive applied in ventricular assist devices. (United States)

    Pohlmann, André; Hameyer, Kay


    Ventricular Assist Devices (VADs) are mechanical blood pumps that support the human heart in order to maintain a sufficient perfusion of the human body and its organs. During VAD operation blood damage caused by hemolysis, thrombogenecity and denaturation has to be avoided. One key parameter causing the blood's denaturation is its temperature which must not exceed 42 °C. As a temperature rise can be directly linked to the losses occuring in the drive system, this paper introduces an efficiency prediction chain for Brushless DC (BLDC) drives which are applied in various VAD systems. The presented chain is applied to various core materials and operation ranges, providing a general overview on the loss dependencies.

  15. A phone-assistive device based on Bluetooth technology for cochlear implant users. (United States)

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


    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.

  16. Subchronic use of the St. Jude centrifugal pump as a mechanical assist device in calves. (United States)

    Curtis, J; Wagner-Mann, C; Mann, F; Demmy, T; Walls, J; Turk, J


    The purpose of this experiment was to study the effects of the St. Jude Lifestream centrifugal pump on hemodynamic and hematologic parameters and the incidence of postmortem findings in a subchronic ex vivo left ventricular assist animal model. Five calves were implanted with the pump as a left ventricular assist device (left atrial to thoracic aorta bypass) and studied for 96 h of continuous pumping under identical conditions. Heparin (100 IU/kg) was administered only in the initial saline pump prime. Throughout the protocol, mean arterial and central venous pressures averaged 102.1 +/- 4.6 and 3.4 +/- 2.2 mm Hg, respectively. Pump flow was 47.8 +/- 8.4 ml/kg/min at a mean pump speed of 1,676.3 +/- 106.1 rpm. No clinical abnormalities or mechanical malfunctions attributable to the pump were detected during the 96 h of continuous pumping for each calf. Mean plasma-free hemoglobin after 96 h was 3.9 +/- 3.7 mumol/L (p = 0.337 compared to baseline). At post mortem, renal infarctions were detected in 1 calf. No other pump-associated lesions were detected in any of the other calves. We have concluded that the St. Jude Lifestream centrifugal pump functions reliably during 96 h of continuous left heart bypass in a calf model.

  17. Development of a fixation device for robot assisted fracture reduction of femoral shaft fractures: a biomechanical study. (United States)

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


    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.

  18. Optimization of the Outflow Graft Position and Angle in a Left Ventricular Assist Device (United States)

    McGah, Patrick; Prisco, Anthony; Beckman, Jennifer; Mokadam, Nahush; Mahr, Claudius; Aliseda, Alberto


    The placement of the outflow graft in the aorta plays a key role in the hemodynamics of Left Ventricle Assist Devices (LVAD), a medical device with a growing importance in the treatment of end-stage heart failure. We use a patient-specific computational model of the VAD and the ascending aorta to investigate the impact of VAD outflow graft configuration on the residence time and wall shear stresses along the ascending aorta and the ostia of the upper branches. The flow induced by the combination of VAD output through the graft anastomosed to the aorta and the limited cardiac output through intermittent opening of the aortic valve is studied to determine the nature of thrombogenic flow patterns. Outflow grafts are virtually anastomosed along the ascending aorta or subclavian artery of the patient-specific model at different positions and angles that are surgically-informed. Detailed markers of thrombosis, such as cell residence time, wall shear stress, and shear stress gradients are analyzed and compared for the different configurations. The angle of incidence of the outflow graft critically influences the volume of recirculating flow between aortic valve and anastomosis, and the aortic pressure acting against aortic valve opening.

  19. Molecular changes after left ventricular assist device support for heart failure. (United States)

    Birks, Emma J


    Heart failure is associated with remodeling that consists of adverse cellular, structural, and functional changes in the myocardium. Until recently, this was thought to be unidirectional, progressive, and irreversible. However, irreversibility has been shown to be incorrect because complete or partial reversal can occur that can be marked after myocardial unloading with a left ventricular assist device (LVAD). Patients with chronic advanced heart failure can show near-normalization of nearly all structural abnormalities of the myocardium or reverse remodeling after LVAD support. However, reverse remodeling does not always equate with clinical recovery. The molecular changes occurring after LVAD support are reviewed, both those demonstrated with LVAD unloading alone in patients bridged to transplantation and those occurring in the myocardium of patients who have recovered enough myocardial function to have the device removed. Reverse remodeling may be attributable to a reversal of the pathological mechanisms that occur in remodeling or the generation of new pathways. A reduction in cell size occurs after LVAD unloading, which does not necessarily correlate with improved cardiac function. However, some of the changes in both the cardiac myocyte and the matrix after LVAD support are specific to myocardial recovery. In the myocyte, increases in the cytoskeletal proteins and improvements in the Ca²⁺ handling pathway seem to be specifically associated with myocardial recovery. Changes in the matrix are complex, but excessive scarring appears to limit the ability for recovery, and the degree of fibrosis in the myocardium at the time of implantation may predict the ability to recover.

  20. Electrospray-assisted characterization and deposition of chlorosomes to fabricate a biomimetic light-harvesting device

    Energy Technology Data Exchange (ETDEWEB)

    Modesto-Lopez, Luis B.; Thimsen, Elijah J.; Collins, Aaron M.; Blankenship, R. E.; Biswas, Pratim


    Photosynthesis is an efficient process by which solar energy is converted into chemical energy. Green photosynthetic bacteria such as Chloroflexus aurantiacus have supramolecular antenna complexes called chlorosomes attached to their cytoplasmic membrane that increase the cross section for light absorption even in low-light conditions. Self-assembled bacteriochlorophyll pigments in the chlorosome interior play a key role in the efficient transfer and funneling of the harvested energy. In this work it was demonstrated that chlorosomes can be rapidly and precisely size-characterized online in real time using an electrospray-assisted mobility-based technique. Chlorosomes were electrospray-deposited onto TiO{sub 2} nanostructured films with columnar morphology to fabricate a novel biomimetic device to overcome the solvent compatibility issues associated with biological particles and synthetic dyes. The assembled unit retained the viability of the chlorosomes, and the harvesting of sunlight over a broader range of wavelengths was demonstrated. It was shown that the presence of chlorosomes in the biomimetic device had a 30-fold increase in photocurrent.

  1. Right Ventricular Function and Left Ventricular Assist Device Placement: Clinical Considerations and Outcomes (United States)

    Lainez, Romeo; Parrino, Gene; Bates, Michael


    The HeartMate II is an axial-flow left ventricular assist device that is approved for the treatment of advanced heart failure as a bridge to transplant or destination therapy. Despite the success of this device, right ventricular failure remains a persistent problem in most studies. Right ventricular dysfunction is usually defined as the need for right heart mechanical support or the persistent requirement for inotropes to support right heart function beyond 14 days. Over 21 months, 45 patients with end-stage heart disease underwent placement of the HeartMate II at our institution. This continuous cohort of patients underwent a retrospective review to evaluate the incidence of right heart failure. The perioperative survival was 91% with no incidents of mechanical support for the right ventricle and no requirements for inotropes beyond 14 days. This survival was consistent to beyond 1 year at the time of the study, and 18% of patients underwent heart transplant with 100% survival. PMID:21603391

  2. The personal lift-assist device and lifting technique: a principal component analysis. (United States)

    Sadler, Erin M; Graham, Ryan B; Stevenson, Joan M


    The personal lift-assist device (PLAD) is a non-motorised, on-body device that acts as an external force generator using the concept of stored elastic energy. In this study, the effect of the PLAD on the lifting kinematics of male and female lifters was investigated using principal component analysis. Joint kinematic data of 15 males and 15 females were collected using an opto-electronic system during a freestyle, symmetrical-lifting protocol with and without wearing the PLAD. Of the 31 Principal Components (PCs) retained in the models, eight scores were significantly different between the PLAD and no-PLAD conditions. There were no main effects for gender and no significant interactions. Results indicated that the PLAD similarly affected the lifting kinematics of males and females; demonstrating significantly less lumbar and thoracic flexion and significantly greater hip and ankle flexion when wearing the PLAD. These findings add to the body of work that suggest the PLAD may be a safe and effective ergonomic aid. STATEMENT OF RELEVANCE: The PLAD is an ergonomic aid that has been shown to be effective at reducing low back demands during manual materials handling tasks. This body of work establishes that the PLAD encourages safe lifting practices without adversely affecting lifting technique.

  3. Clinical, Molecular and Genetic Changes in Response to a Left Ventricular Assist Device (United States)

    Hall, Jennifer L.; Fermin, David R.; Birks, Emma J.; Barton, Paul J.R.; Slaughter, Mark; Eckman, Peter; Baba, Hideo A.; Wohlschlaeger, Jeremias Jeremias; Miller, Leslie W.


    The use of left ventricular assist devices (LVADs) in treating patients with end stage heart failure has increased significantly in recent years, both as a bridge to transplant and as destination therapy in those who are ineligible for cardiac transplantation. This increase is based largely on the results of several recently completed clinical trials with the new second generation continuous flow devices that showed significant improvement in survival, functional capacity, and quality of life. Additional information on the use of the first generation and second generation LVADs has come from a recently released report spanning the years 2006–2009, from The Interagency Registry for Mechanical Circulatory Support (INTERMACS), a National Heart Lung and Blood Institute sponsored collaboration between the United States Food and Drug Administration (FDA), the Center for Medicare and Medicaid (CMS) and the scientific community (1). This paper provides a review of the latest clinical trials and data from the INTERMACS registry with tight integration of the landmark molecular, cellular and genomic research that accompanies the reverse remodeling of the human heart in response to the LVAD and functional recovery that has been reported in a subset of these patients. PMID:21292124

  4. [Temporary use of centrifugal pump for pump thrombosis in patients with paracorporeal ventricular assist device]. (United States)

    Kimura, Mitsutoshi; Kinoshita, Osamu; Nawata, Kan; Yamauchi, Haruo; Itoda, Yoshifumi; Hoshino, Yasuhiro; Kashiwa, Koichi; Kubo, Hitoshi; Kurosawa, Hideo; Takahashi, Mai; Koga, Sayaka; Ono, Minoru


    Nipro paracorporeal ventricular assist device( VAD) is often associated with pump thrombosis which causes severe complications such as brain infarction, often requiring pump change. However, Nipro VAD pump is an expensive device and it is difficult to change pumps frequently at a short interval. We have temporarily used Rotaflow centrifugal pump for recurrent pump thrombosis in patients with Nipro VADs. From January 2012 through December 2013, 19 patients underwent Nipro VADs implantation at our institution, and 9 of them underwent pump change from Nipro pumps to Rotaflow centrifugal pumps. A total of 25 Rotaflow centrifugal pumps were used in these 9 patients, with the total circulatory support duration of 526 days. The median support period was 15 days (range;2-128 days). There were 2 cerebrovascular accidents and 1 Rotaflow pump circuit thrombosis during this period. Change from Rotaflow to Nipro VAD pump resulted in decrease in hematocrit by about 3 point. There was no difference in liver or renal function between before and after the pump change. Our results suggest that temporary use of Rotaflow centrifugal pump for recurrent pump thrombosis in patients with Nipro VADs may be a promising alternative.

  5. Centrifugal blood pump for temporary ventricular assist devices with low priming and ceramic bearings. (United States)

    Leme, Juliana; da Silva, Cibele; Fonseca, Jeison; da Silva, Bruno Utiyama; Uebelhart, Beatriz; Biscegli, José F; Andrade, Aron


    A new model of centrifugal blood pump for temporary ventricular assist devices has been developed and evaluated. The design of the device is based on centrifugal pumping principles and the usage of ceramic bearings, resulting in a pump with reduced priming (35 ± 2 mL) that can be applied for up to 30 days. Computational fluid dynamic (CFD) analysis is an efficient tool to optimize flow path geometry, maximize hydraulic performance, and minimize shear stress, consequently decreasing hemolysis. Initial studies were conducted by analyzing flow behavior with different impellers, aiming to determine the best impeller design. After CFD studies, rapid prototyping technology was used for production of pump prototypes with three different impellers. In vitro experiments were performed with those prototypes, using a mock loop system composed of Tygon tubes, oxygenator, digital flow meter, pressure monitor, electronic driver, and adjustable clamp for flow control, filled with a solution (1/3 water, 1/3 glycerin, 1/3 alcohol) simulating blood viscosity and density. Flow-versus-pressure curves were obtained for rotational speeds of 1000, 1500, 2000, 2500, and 3000 rpm. As the next step, the CFD analysis and hydrodynamic performance results will be compared with the results of flow visualization studies and hemolysis tests.

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

    Directory of Open Access Journals (Sweden)

    Suzana Rabello


    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.

  7. Comparison of novel physiological load-adaptive control strategies for ventricular assist devices. (United States)

    Habigt, Moriz; Ketelhut, Maike; Gesenhues, Jonas; Schrödel, Frank; Hein, Marc; Mechelinck, Mare; Schmitz-Rode, Thomas; Abel, Dirk; Rossaint, Rolf


    Terminal heart failure (HF) is the most prevalent cause of death in the Western world and the implantation of a left ventricular assist device (LVAD) has become the gold standard therapy today. Most of the actually implanted devices are driven at a constant speed (CS) regardless of the patient's physiological demand. A new physiological controller [power ratio (PR) controller], which keeps a constant ratio between LVAD power and left ventricular power, a previous concept [preload responsive speed (PRS) controller], which adds a variable LVAD power to reach a defined stroke work, and a CS controller were compared with an unimpaired ventricle in a full heart computer simulation model. The effects of changes in preload, afterload and left ventricular contractility are displayed by global hemodynamics and ventricular pressure-volume loops. Both physiological controllers demonstrated the desired load dependency, whereas the PR controller exceeded the PRS controller in response to an increased load and contractility. Response was inferior when preload or contractility was decreased. Thus, the PR controller might lead to an increased exercise tolerance of the patient. Additional studies are required to evaluate the controllers in vivo.

  8. CPA-VoD:Cloud and Peer-Assisted Video on Demand System for Mobile Devices

    Institute of Scientific and Technical Information of China (English)

    Lei-Gen Cheng; Laizhong Cui; Yong Jiang


    With the rapid development of WiFi and 3G/4G, people tend to view videos on mobile devices. These devices are ubiquitous but have small memory to cache videos. As a result, in contrast to traditional computers, these devices aggravate the network pressure of content providers. Previous studies use CDN to solve this problem. But its static leasing mechanism in which the rental space cannot be dynamically adjusted makes the operational cost soar and incompatible with the dynamically video delivery. In our study, based on a thorough analysis of user behavior from Tencent Video, a popular Chinese on-line video share platform, we identify two key user behaviors. Firstly, lots of users in the same region tend to watch the same video. Secondly, the popularity distribution of videos conforms with the Pareto principle, i.e., the top 20%popular videos own 80%of all video traffic. To turn these observations into silver bullet, we propose and implement a novel cloud- and peer-assisted video on demand system (CPA-VoD). In the system, we group users in the same region as a peer swarm, and in the same peer swarm, users can provide videos to other users by sharing their cached videos. Besides, we cache the 10% most popular videos in cloud servers to further alleviate the network pressure. We choose cloud servers to cache videos because the rental space can be dynamically adjusted. According to the evaluation on a real dataset from Tencent Video, CPA-VoD alleviates the network pressure and the operation cost excellently, while only 20.9% traffic is serviced by the content provider.

  9. Functional status of United States children supported with a left ventricular assist device at heart transplantation. (United States)

    Bulic, Anica; Maeda, Katsuhide; Zhang, Yulin; Chen, Sharon; McElhinney, Doff B; Dykes, John C; Hollander, Amanda M; Hollander, Seth A; Murray, Jenna; Reinhartz, Olaf; Gowan, Mary Alice; Rosenthal, David N; Almond, Christopher S


    As survival with pediatric left ventricular assist devices (LVADs) has improved, decisions regarding the optimal support strategy may depend more on quality of life and functional status (FS) rather than mortality alone. Limited data are available regarding the FS of children supported with LVADs. We sought to compare the FS of children supported with LVADs vs vasoactive infusions to inform decision making around support strategies. Organ Procurement and Transplant Network data were used to identify all United States children aged between 1 and 21 years at heart transplant (HT) between 2006 and 2015 for dilated cardiomyopathy and supported with an LVAD or vasoactive infusions alone at HT. FS was measured using the 10-point Karnofsky and Lansky scale. Of 701 children who met the inclusion criteria, 430 (61%) were supported with vasoactive infusions, and 271 (39%) were supported with an LVAD at HT. Children in the LVAD group had higher median FS scores at HT than children in the vasoactive infusion group (6 vs 5, p < 0.001) but lower FS scores at listing (4 vs 6, p < 0.001). The effect persisted regardless of patient location at HT (home, hospital, intensive care) or device type. Discharge by HT occurred in 46% of children in the LVAD group compared with 26% of children in the vasoactive infusion cohort (p = 0.001). Stroke was reported at HT in 3% of children in the LVAD cohort and in 1% in the vasoactive infusion cohort (p = 0.04). Among children with dilated cardiomyopathy undergoing HT, children supported with LVADs at HT have higher FS than children supported with vasoactive infusions at HT, regardless of device type or hospitalization status. Children supported with LVADs at HT were more likely to be discharged from the hospital but had a higher prevalence of stroke at HT. Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  10. A Review of Assistive Listening Device and Digital Wireless Technology for Hearing Instruments (United States)

    Kim, Chun Hyeok


    Assistive listening devices (ALDs) refer to various types of amplification equipment designed to improve the communication of individuals with hard of hearing to enhance the accessibility to speech signal when individual hearing instruments are not sufficient. There are many types of ALDs to overcome a triangle of speech to noise ratio (SNR) problems, noise, distance, and reverberation. ALDs vary in their internal electronic mechanisms ranging from simple hard-wire microphone-amplifier units to more sophisticated broadcasting systems. They usually use microphones to capture an audio source and broadcast it wirelessly over a frequency modulation (FM), infra-red, induction loop, or other transmission techniques. The seven types of ALDs are introduced including hardwire devices, FM sound system, infra-red sound system, induction loop system, telephone listening devices, television, and alert/alarm system. Further development of digital wireless technology in hearing instruments will make possible direct communication with ALDs without any accessories in the near future. There are two technology solutions for digital wireless hearing instruments improving SNR and convenience. One is near-field magnetic induction combined with Bluetooth radio frequency (RF) transmission or proprietary RF transmission and the other is proprietary RF transmission alone. Recently launched digital wireless hearing aid applying this new technology can communicate from the hearing instrument to personal computer, phones, Wi-Fi, alert systems, and ALDs via iPhone, iPad, and iPod. However, it comes with its own iOS application offering a range of features but there is no option for Android users as of this moment. PMID:25566400

  11. A review of assistive listening device and digital wireless technology for hearing instruments. (United States)

    Kim, Jin Sook; Kim, Chun Hyeok


    Assistive listening devices (ALDs) refer to various types of amplification equipment designed to improve the communication of individuals with hard of hearing to enhance the accessibility to speech signal when individual hearing instruments are not sufficient. There are many types of ALDs to overcome a triangle of speech to noise ratio (SNR) problems, noise, distance, and reverberation. ALDs vary in their internal electronic mechanisms ranging from simple hard-wire microphone-amplifier units to more sophisticated broadcasting systems. They usually use microphones to capture an audio source and broadcast it wirelessly over a frequency modulation (FM), infra-red, induction loop, or other transmission techniques. The seven types of ALDs are introduced including hardwire devices, FM sound system, infra-red sound system, induction loop system, telephone listening devices, television, and alert/alarm system. Further development of digital wireless technology in hearing instruments will make possible direct communication with ALDs without any accessories in the near future. There are two technology solutions for digital wireless hearing instruments improving SNR and convenience. One is near-field magnetic induction combined with Bluetooth radio frequency (RF) transmission or proprietary RF transmission and the other is proprietary RF transmission alone. Recently launched digital wireless hearing aid applying this new technology can communicate from the hearing instrument to personal computer, phones, Wi-Fi, alert systems, and ALDs via iPhone, iPad, and iPod. However, it comes with its own iOS application offering a range of features but there is no option for Android users as of this moment.

  12. Prolonged sustained ventricular fibrillation without loss of consciousness in patients supported by a left ventricular assist device. (United States)

    Fasseas, Panayotis; Kutalek, Steven P; Kantharia, Bharat K


    Patients with cardiomyopathy of either ischemic or nonischemic origin are at increased risk for malignant ventricular arrhythmias. Normally sustained ventricular fibrillation (VF) leads to death very rapidly. We report two patients who remained in sustained VF, supported by a left ventricular assist device, for a prolonged period of time. Perfusion pressure through the device was sufficient to allow the patients to remain awake and responsive for several hours while in VF. The cases represent two of the longest reported episodes of sustained VF recorded in awake patients implanted with such devices.

  13. [The electric heart assist device for patients on the waiting list for a heart transplant: a bridge too far

    NARCIS (Netherlands)

    Verheugt, F.W.A.


    Left-ventricular assist devices are being increasingly used as a bridge to heart transplantation in patients with end-stage heart failure. However, current evidence does not support their widespread application for this indication. Other indications such as cardiogenic shock in acute myocardial infa

  14. First report of a left ventricular assist device infection caused by Staphylococcus schleiferi subspecies coagulans: a coagulase-positive organism. (United States)

    Thibodeau, Evangeline; Boucher, Helen; Denofrio, David; Pham, Duc Thinh; Snydman, David


    Staphylococcus schleiferi subspecies coagulans is often misclassified as S. aureus given the production of a pseudocoagulase turning the tube coagulase test positive. It is therefore infrequently reported in the literature. We describe the first case of S. schleiferi subspecies coagulans left ventricular assist device infection in a patient awaiting heart transplantation.

  15. Use of plasma "reconstitution" during cardio pulmonary bypass for a heart transplant after previous left ventricular assist device implant surgery. (United States)

    Babaev, A; Saczkowski, R; Hynes, M; Boodhwani, M; Hudson, C C C


    The case report describes a novel technique of pre-emptive plasma "reconstitution" prior to disengagement from cardiopulmonary bypass (CPB) to minimize RV volume overload. The concomitant use of hemoconcentration facilitates volume and blood product management in cardiac transplant after previous left ventricular assist device implant surgery.

  16. 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;


    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...

  17. Nipro extra-corporeal left ventricular assist device fitting after left ventricular reconstruction with mitral valve plasty. (United States)

    Arakawa, Mamoru; Yamaguchi, Atsushi; Nishimura, Takashi; Itoh, Satoshi; Yuri, Koichi; Kyo, Shunei; Adachi, Hideo


    Both left ventricular assist device and left ventricular reconstruction are treatment choices for severe heart failure conditions. Our institution performed a left ventricular assist device installation following a left ventricular reconstruction procedure on a 42-year-old male patient who presented with dilated cardiomyopathy and low cardiac output syndrome. A mitral valve plasty was used to correct the acute mitral valve regurgitation and we performed a Nipro extra-corporeal left ventricular assist device installation on post-operative day 14. Due to the left ventricular reconstruction that the patient had in a previous operation, we needed to attach an apical cuff on posterior apex, insert the inflow cannula with a large curve, and shift the skin insertion site laterally to the left. We assessed the angle between the cardiac longitudinal axis and the inflow cannula using computed tomography. The patient did not complain of any subjective symptoms of heart failure. Although Nipro extra-corporeal left ventricular assist device installation after left ventricular reconstruction has several difficulties historically, we have experienced a successful case.

  18. Experience with the Sarns centrifugal pump as a ventricular assist device. (United States)

    Joyce, L D; Kiser, J C; Eales, F; King, R M; Toninato, C J; Hansen, J


    The authors used the Sarns centrifugal pump (Sarns 3M, Ann Arbor, MI) as a ventricular assist device (VAD) in 30 patients between May 1985 and February 1990. Sixteen patients were unweanable from cardiopulmonary bypass at the time of surgery; nine were patients who developed cardiogenic shock postoperatively in the intensive care unit. One was a donor organ failure; one had a failed PTCA; and one an acute myocardial infarction with cardiogenic shock preoperatively. Two patients were bridged to cardiac transplantation. Of the 28 nontransplant candidates, 20 (71.4%) were weaned successfully, 14 (50%) were discharged from the hospital, and 13 (46%) are alive from 1 to 46 months postoperatively (mean, 21.1 months). Three patients received right ventricular support alone; all three were weaned, and two (66.7%) were discharged. Ten patients received left ventricular assistance alone. Six (60%) were weaned, and four (40%) were discharged. Two patients received left ventricular support initially but were taken back for right VAD insertion because of right-sided heart failure; one (50%) is alive. Fifteen patients received biventricular support. Eleven (77.3%) were weaned, and eight (53.3%) were discharged. Patient ages ranged from 19 to 73 years, with a mean age for men of 59 years and 50.5 years for women. There were no thromboembolic events. Various clinical parameters were evaluated to determine effect on weanability and survival. These results show survival equivalent to any other VAD at this time. The centrifugal pump is a convenient and effective means of maintaining ventricular support in individuals who are believed to have salvageable myocardium.

  19. Surface-Assisted Luminescence: The PL Yellow Band and the EL of n-GaN Devices

    Directory of Open Access Journals (Sweden)

    José Ignacio Izpura


    Full Text Available Although everybody should know that measurements are never performed directly on materials but on devices, this is not generally true. Devices are physical systems able to exchange energy and thus subject to the laws of physics, which determine the information they provide. Hence, we should not overlook device effects in measurements as we do by assuming naively that photoluminescence (PL is bulk emission free from surface effects. By replacing this unjustified assumption with a proper model for GaN surface devices, their yellow band PL becomes surface-assisted luminescence that allows for the prediction of the weak electroluminescence recently observed in n-GaN devices when holes are brought to their surfaces.

  20. Successful trans-Atlantic air ambulance transfer of a patient supported by a bi-ventricular assist device. (United States)

    McLean, Neilson; Copeland, Ryan; Casey, Neil; Samoukovic, Gordon; Quigley, Robert


    The ventricular assist device (VAD) is a hemodynamic support device that augments cardiac output for patients with severe ventricular dysfunction. With improved reliability and technological advances, the use of VADs to support patients is increasing. Many VAD-dependent patients ultimately require heart transplants that are only available in specialized centers, necessitating an interhospital transfer. To date there are few reports of long-distance fixed wing aeromedical transport of patients dependent on a VAD. Here we describe the successful transfer of a patient supported by a biventricular assist device (BiVAD) from Cambridge, UK, to Durham, NC, via fixed-wing jet aircraft. During this transfer, we observed hemodynamic alterations secondary to gravitational forces, which should be anticipated and may be mitigated with simple maneuvers. With high-level logistical planning and appropriate medical oversight, patients dependant on BiVADs can be safely transported by fixed wing aircraft over long distances.

  1. Left ventricular assist devices and gastrointestinal bleeding: a narrative review of case reports and case series. (United States)

    Islam, Sameer; Cevik, Cihan; Madonna, Rosalinda; Frandah, Wesam; Islam, Ebtesam; Islam, Sherazad; Nugent, Kenneth


    The use of left ventricular assist devices (LVADs) has become a state-of-the-art therapy for advanced cardiac heart failure; however, multiple reports in the literature describe an increased risk for gastrointestinal (GI) bleeding in these patients. We characterized this association by reviewing recent studies on this topic. GI bleeding occurs frequently in patients with LVADs, especially with devices with nonpulsatile flow patterns. We performed a comprehensive literature review to identify articles that reported GI bleeding in patients with LVADs. Databases used included PubMed, EMBASE, Scopus, Web of Knowledge, and Ovid. Baseline and outcome data were then ed from these reports. We identified 10 case reports and 22 case series with 1543 patients. The mean age was 54.2 years. Most patients had nonpulsatile LVADs (1316, 85.3%). Three hundred and seventeen patients (20.5%) developed GI bleeding; this occurred more frequently in patients with nonpulsatile LVADs. Multiple procedures were performed without complications but often did not identify a definite bleeding site. Suspect lesions occurred throughout the GI tract but were more frequent in the upper GI tract. Many patients had arteriovenous malformations. All patients received medical therapy. None of the patients had their LVAD replaced. The use of anticoagulation did not appear to predispose these patients to more GI bleeding episodes. Patients with LVADs have frequent GI bleeds, especially from arteriovenous malformations, which can occur throughout the GI tract. Most diagnostic and therapeutic interventions can be used safely in these patients. The pathogenesis of the GI bleeding in these patients may involve the use of anticoagulant medications, the formation of arteriovenous malformations, loss of von Willebrand factor activity, and mucosal ischemia. © 2013 Wiley Periodicals, Inc.

  2. Development of an inlet pressure sensor for control in a left ventricular assist device. (United States)

    Fritz, Bryan; Cysyk, Joshua; Newswanger, Ray; Weiss, William; Rosenberg, Gerson


    A Tesla type continuous flow left ventricular assist device (VAD) has been designed by Penn State and Advanced Bionics, Inc. (ABI). When a continuous flow device is used, care must be taken to limit low pressures in the ventricle, which can produce an obstruction to the inlet cannula or trigger arrhythmias. Design of an inexpensive, semiconductor strain gauge inlet pressure sensor to detect suction has been completed. The research and design analysis included finite element modeling of the sensing region. Sensitivity, step-response, temperature dependence, and hysteresis tests have been performed on prototype units. All sensors were able to withstand the maximum expected strain of 82 microm/in at 500 mm Hg internal pressure. Average sensitivity was 0.52 +/- 0.24 microV/mm Hg with 0.5 V excitation (n = 5 units). Step-response time for a 0- to 90-mm Hg step change averaged 22 msec. Hysteresis was measured by applying and holding 75 mm Hg internal pressure for 4 hours, followed by a zero pressure measurement, and ranged from -15 to 4.1 mm Hg (n = 3 units). Offset drift varied between 180 and -140 mm Hg over a 4-week period (n = 2 units). Span temperature sensitivity ranged from 18 to -21 muV/ degrees C (n = 5 units). Gain temperature sensitivity ranged from -7.4 to 4.9 muV/ degrees C (n = 5 units). With the inherent drift, it is currently not possible to use the transducer to measure actual pressures, but it can easily be used to measure pressure changes throughout the cardiac cycle. This signal can then be used in the control system to avoid ventricular suction events.

  3. iOS--Worthy of the Hype as Assistive Technology for Visual Impairments? A Phenomenological Study of iOS Device Use by Individuals with Visual Impairments (United States)

    Scott, Shari


    This qualitative study sought to explore the shared essence of the lived experiences of early adopters of iOS devices as assistive technology by persons with visual impairments. The capstone question addressed the idea of whether any one device could fully meet the assistive technology needs of this population. Purposeful sampling methods were…

  4. Control of a haptic gear shifting assistance device utilizing a magnetorheological clutch (United States)

    Han, Young-Min; Choi, Seung-Bok


    This paper proposes a haptic clutch driven gear shifting assistance device that can help when the driver shifts the gear of a transmission system. In order to achieve this goal, a magnetorheological (MR) fluid-based clutch is devised to be capable of the rotary motion of an accelerator pedal to which the MR clutch is integrated. The proposed MR clutch is then manufactured, and its transmission torque is experimentally evaluated according to the magnetic field intensity. The manufactured MR clutch is integrated with the accelerator pedal to transmit a haptic cue signal to the driver. The impending control issue is to cue the driver to shift the gear via the haptic force. Therefore, a gear-shifting decision algorithm is constructed by considering the vehicle engine speed concerned with engine combustion dynamics, vehicle dynamics and driving resistance. Then, the algorithm is integrated with a compensation strategy for attaining the desired haptic force. In this work, the compensator is also developed and implemented through the discrete version of the inverse hysteretic model. The control performances, such as the haptic force tracking responses and fuel consumption, are experimentally evaluated.

  5. Intractable Hematuria After Left Ventricular Assist Device Implantation: Can Lessons Learned from Gastrointestinal Bleeding Be Applied? (United States)

    Son, Andre Y; Zhao, Lee; Reyentovich, Alex; Deanda, Abe; Balsam, Leora B


    Patients with continuous-flow left ventricular assist devices (CF-LVADs) are at increased risk of bleeding. We reviewed our institutional experience with bleeding in the urinary tract after CF-LVAD implantation and quantified the impact on hospital resource utilization in comparison with bleeding in the gastrointestinal (GI) tract, the most commonly reported mucosal site of bleeding after LVAD implantation. Records were retrospectively reviewed for patients undergoing CF-LVAD implantation at our institution between October 2011 and April 2015. Major adverse events of gross hematuria and GI bleeding were identified, and patient demographics and hospital course were reviewed. Gross hematuria occurred in 3 of the 35 patients (8.6%) and in 5.1% of all hospitalizations for CF-LVAD patients. Severe hematuria occurred after traumatic urethral catheterization, urinary retention, or urologic surgery. Hospitalization for hematuria was six times less likely than hospitalization for GI bleeding; however, hematuria hospitalizations lasted 3.2 times longer than GI bleeding hospitalizations (17.0 vs. 5.3 days). Late recurrent gross hematuria occurred in all cases, with rehospitalization occurring after 109 ± 53 days. In conclusion, gross hematuria is an infrequent but morbid bleeding complication in CF-LVAD patients. Strategies to avoid this complication include strict avoidance of traumatic urethral catheterization and urinary retention in high-risk patients.

  6. An extended computational model of the circulatory system for designing ventricular assist devices. (United States)

    Hsu, Po-Lin; Cheng, Sean J; Saumarez, Richard C; Dawes, William N; McMahon, Richard A


    An extended computational model of the circulatory system has been developed to predict blood flow in the presence of ventricular assist devices (VADs). A novel VAD, placed in the descending aorta, intended to offload the left ventricle (LV) and augment renal perfusion is being studied. For this application, a better understanding of the global hemodynamic response of the VAD, in essence an electrically driven pump, and the cardiovascular system is necessary. To meet this need, a model has been established as a nonlinear, lumped-parameter electrical analog, and simulated results under different states [healthy, congestive heart failure (CHF), and postinsertion of VAD] are presented. The systemic circulation is separated into five compartments and the descending aorta is composed of three components to accurately yield the system response of each section before and after the insertion of the VAD. Delays in valve closing time and blood inertia in the aorta were introduced to deliver a more realistic model. Pump governing equations and optimization are based on fundamental theories of turbomachines and can serve as a practical initial design point for rotary blood pumps. The model's results closely mimic established parameters for the circulatory system and confirm the feasibility of the intra-aortic VAD concept. This computational model can be linked with models of the pump motor to provide a valuable tool for innovative VAD design.

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

    Directory of Open Access Journals (Sweden)

    Sandy von Salisch


    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.

  8. Left ventricular assist devices improve functional class without normalizing peak oxygen consumption. (United States)

    Benton, Casey R; Sayer, Gabriel; Nair, Ajith P; Ashley, Kimberly; Domanski, Michael J; Henzlova, Milena J; Anyanwu, Anelechi C; Pinney, Sean P


    Heart failure patients supported with left ventricular assist devices (LVAD) enjoy improvements in functional capacity and quality of life. We reasoned that such improvements in exercise capacity should be reflected in an objective increase in peak oxygen consumption as measured by cardiopulmonary exercise testing (CPET). We performed a retrospective review of all recipients of a HeartMate II LVAD at our center from June 2009 to June 2012 who completed CPET. Thirty-seven patients completed CPET an average of 6 months after implantation. Of these, 10 patients had CPET performed before LVAD implantation. Overall, 91.4% of patients improved by at least two New York Heart Association classes, with 34.3% improving by three classes. Postimplant VO2 max was significantly less than predicted (14.7 ± 3.1 vs. 29.8 ± 6.6 ml/kg/min, p VO2 max increased significantly from 11.6 ± 5.0 to 15.4 ± 3.9 ml/kg/min (p = 0.009). VO2 max improves significantly with LVAD support but fails to normalize to predicted values, in spite of improvements in functional class. The severity of preimplantation heart failure does not associate with the degree of VO2 max improvement.

  9. Feasibility of Home-Use Animal-Assisted Activities in Patients With Implanted Cardiac Electronic Devices

    Directory of Open Access Journals (Sweden)

    Peter Jirak


    Full Text Available Animal-assisted activities (AAAs are mainly carried out in institutions. The aim of this prospective pilot study was to assess the willingness of patients with cardiac implanted electronic devices (IEDs to participate in AAA. The sample included 75 ambulatory patients (18 females, M age = 69 years, who attended an outpatient clinic for control of antibradycardic pacemakers (n = 15 or implanted cardioverter defibrillators (n = 60. Twenty-three percent were current and 48% were previous pet-owners. Current pet-owners were younger than non-pet-owners (63.5 vs. 72.0 years, p = .0003. Twelve patients (16% showed interest in AAA visits. However, only two patients agreed to an AAA visit. Both patients were visited once, but declined further visits. Hence, AAA sessions at home were poorly accepted, mainly because the patients considered themselves too busy or healthy, or due to a general disinterest in AAA. Potential health benefits associated with AAA may not be feasible to investigate during home visits of AAA-teams in patients with IEDs who are healthy enough to leave their homes. For further studies concerning AAA in patients with cardiovascular diseases, we suggest focusing on institutions like rehabilitation centers or day care centers and on more severely sick, homebound patients.

  10. The Spectrum of General Surgery Interventions in Pediatric Patients with Ventricular Assist Devices. (United States)

    Kamel, Fady; Buchholz, Holger; Dicken, Bryan; Conway, Jennifer


    Ventricular assist devices (VADs) have positively impacted the management of heart failure. However, they come with a range of complications. Although general surgical complications have been assessed in adults with VADs, there is no study to date that has assessed general surgery intervention in the pediatric population. Fifty-two patients who received VADs from 2005 to 2015 at the Stollery Children's Hospital were assessed for general surgery intervention and anticoagulation status at the time of intervention. Eighteen patients (35%) had general surgery intervention; there were 21 nonemergency procedures and six emergency procedures performed. For nonemergency procedures, 89% of patients had anticoagulation held within 24 hours of surgery and 84% had anticoagulation resumed within 4 hours postoperatively. Antiplatelet therapy was not held perioperatively. In both emergency and nonemergency procedures, anticoagulation status was not a factor in the success of the procedure. This study shows that it is safe to have general surgery intervention on the same admission as a VAD implant provided an appropriate interdisciplinary healthcare team is involved with the perioperative management of the patient.

  11. Differential optical spectropolarimetric imaging system assisted by liquid crystal devices for skin imaging (United States)

    Aharon, Ofir; Abdulhalim, Ibrahim; Arnon, Ofer; Rosenberg, Lior; Dyomin, Victor; Silberstein, Eldad


    Skin cancer diagnosis depends not only on histopathological examination but also on visual inspection before and after the excision of suspected lesion. Neoplasm is accompanied with changes in birefringence of collagen, pleomorphicity, and hyperchromatic state of epithelial nuclei. These phenomena can be measured by spectral and polarization changes of light backscattered by the examined tissue. A new differential spectropolarimetric system is proposed using liquid crystal devices, one as a tunable filter and the other as a polarization rotator, both operating at wide spectral ranges from the visible to the near-infrared. Since collagen's fibrils texture orientation depends on its location in the skin and since it is not well organized, our system scans the bipolarization states by continuously rotating the linearly polarized light incident on a skin lesion, and collecting differential contrasts between sequenced images when simultaneously averaging the statistical readout of a video camera. This noninvasive method emphasizes areas on skin where the neoplasm, or tumor, minimizes the statistical polarization change of the scattered light from the lesion. The module can be considered as an assistant tool for epiluminescence microscopy. Images of skin tumors were captured in vivo before the patients having their surgery and compared to histopathological results.

  12. Ventricular Assist Device in Single-Ventricle Heart Disease and a Superior Cavopulmonary Anastomosis. (United States)

    Niebler, Robert A; Shah, Tejas K; Mitchell, Michael E; Woods, Ronald K; Zangwill, Steven D; Tweddell, James S; Berger, Stuart; Ghanayem, Nancy S


    Our objective is to describe the use of a ventricular assist device (VAD) in single-ventricle patients with circulatory failure following superior cavopulmonary anastomosis (SCPA). We performed a retrospective chart review of all single-ventricle patients supported with a VAD following SCPA. Implantation techniques, physiologic parameters while supported, medical and surgical interventions postimplant, and outcomes were reviewed. Four patients were supported with an EXCOR Pediatric (Berlin Heart Inc., The Woodlands, TX, USA) following SCPA for a median duration of 10.5 days (range 9-312 days). Selective excision of trabeculae and chords facilitated apical cannulation in all patients without inflow obstruction. There were two pump exchanges in the one patient supported for 312 days. Two patients were evaluated by cardiac catheterization while supported. Three of four patients were successfully bridged to transplantation. One patient died while supported. All patients had significant bleeding at the time of transplantation, and one required posttransplant extracorporeal membrane oxygenation with subsequent full recovery. VAD support can provide a successful bridge to transplantation in patients with single-ventricle circulation following SCPA. A thorough understanding of the challenges encountered during this support is necessary for successful outcomes.

  13. The ArtAssist Device in chronic lower limb ischemia. A pilot study. (United States)

    Louridas, G; Saadia, R; Spelay, J; Abdoh, A; Weighell, W; Arneja, A S; Tanner, J; Guzman, R


    Patients with chronic critical limb ischemia following a failed bypass graft or with non-reconstructable distal disease diagnosed angiographically, have a very poor prognosis. This is a prospective pilot study to assess the influence of the ArtAssist Device on pedal blood flow and amputation rate. Thirty-three legs in 25 patients were evaluated. Ten legs presented with rest pain, and 23 legs with tissue loss. Nine legs had previously undergone bypass surgery. At a mean follow-up of 3 months, 14 (42%) legs were amputated, and 19 (58%) were saved. Eleven of the amputated legs were in patients with chronic renal failure, a known risk factor. The amputation rate, excluding this group, was 13.6% (3/22). Toe pressures measured initially and after 3 months on the pump showed a significant improvement (p=0.03). Forty percent of patients presenting with rest pain improved, while 26% of foot ulcers healed on the pump. Mortality rate was 12%. The results from this prospective study are encouraging but need to be validated in a larger prospective randomized study.

  14. Performance of a continuous flow ventricular assist device: magnetic bearing design, construction, and testing. (United States)

    Allaire, P; Hilton, E; Baloh, M; Maslen, E; Bearnson, G; Noh, D; Khanwilkar, P; Olsen, D


    A new centrifugal continuous flow ventricular assist device, the CFVAD III, which is fully magnetic bearing suspended, has been developed. It has only one moving part (the impeller), has no contact (magnetic suspension), is compact, and has minimal heating. A centrifugal impeller of 2 inch outer diameter is driven by a permanent magnet brushless DC motor. This paper discusses the design, construction, testing, and performance of the magnetic bearings in the unit. The magnetic suspension consists of an inlet side magnetic bearing and an outlet side magnetic bearing, each divided into 8 pole segments to control axial and radial displacements as well as angular displacements. The magnetic actuators are composed of several different materials to minimize size and weight while having sufficient load capacity to support the forces on the impeller. Flux levels in the range of 0.1 T are employed in the magnetic bearings. Self sensing electronic circuits (without physical sensors) are employed to determine the impellar position and provide the feedback control signal needed for the magnetic bearing control loops. The sensors provide position sensitivity of approximately 0.025 mm. A decentralized 5 axis controller has been developed using modal control techniques. Proportional integral derivative controls are used for each axis to levitate the magnetically supported impeller.

  15. The Importance of the Management of Infectious Complications for Patients with Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Michinari Hieda


    Full Text Available A left ventricular assist device (LVAD therapy is the viable option for patients with advanced heart failure as a bridge to transplantation, bridge to recovery, or destination therapy. Although application of LVAD support has become a standard option, serious complications or adverse events related with LVAD remain a concern. LVAD-related infection including driveline infection (DLI and bloodstream infection (BSI is one of the serious clinical matters for LVAD patients, and especially BSI leads to the high incidence of mortality. The LVAD-related infections negatively impact patient’s quality of life. Therefore, control of infection is one of the primary goals of management in LVAD patients. Several efforts including early and appropriate intervention including antibiotics and wound care may contribute to avert the progress into BSI from localized DLI. Particularly, there are clinical secrets in how to use antibiotics and how to treat wound care in LVAD patients. The rational way of thinking for wound care will be introduced in this review.

  16. The Importance of the Management of Infectious Complications for Patients with Left Ventricular Assist Device (United States)

    Hieda, Michinari; Sata, Makoto; Nakatani, Takeshi


    A left ventricular assist device (LVAD) therapy is the viable option for patients with advanced heart failure as a bridge to transplantation, bridge to recovery, or destination therapy. Although application of LVAD support has become a standard option, serious complications or adverse events related with LVAD remain a concern. LVAD-related infection including driveline infection (DLI) and bloodstream infection (BSI) is one of the serious clinical matters for LVAD patients, and especially BSI leads to the high incidence of mortality. The LVAD-related infections negatively impact patient’s quality of life. Therefore, control of infection is one of the primary goals of management in LVAD patients. Several efforts including early and appropriate intervention including antibiotics and wound care may contribute to avert the progress into BSI from localized DLI. Particularly, there are clinical secrets in how to use antibiotics and how to treat wound care in LVAD patients. The rational way of thinking for wound care will be introduced in this review. PMID:27417794

  17. Heart failure medications prescribed at discharge for patients with left ventricular assist devices. (United States)

    Shreibati, Jacqueline Baras; Sheng, Shubin; Fonarow, Gregg C; DeVore, Adam D; Yancy, Clyde W; Bhatt, Deepak L; Schulte, Phillip; Peterson, Eric D; Hernandez, Adrian; Heidenreich, Paul A


    Real-world use of traditional heart failure (HF) medications for patients with left ventricular assist devices (LVADs) is not well known. We conducted a retrospective, observational analysis of 1,887 advanced HF patients with and without LVADs from 32 LVAD hospitals participating in the Get With The Guidelines-Heart Failure registry from January 2009 to March 2015. We examined HF medication prescription at discharge, temporal trends, and predictors of prescription among patients with an in-hospital (n = 258) or prior (n = 171) LVAD implant, and those with advanced HF but no LVAD, as defined by a left ventricular ejection fraction ≤25% and in-hospital receipt of intravenous inotropes or vasopressin receptor antagonists (n = 1,458). For β-blocker and angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEI/ARB), discharge prescriptions were 58.9% and 53.5% for new LVAD patients, 53.8% and 42.9% for prior LVAD patients, and 73.4% and 63.2% for patients without LVAD support, respectively (both P medication in this population. Further research is needed on the optimal medical regimen for patients with LVADs. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. The Role of Computed Tomography in Predicting Left Ventricular Assist Device Infectious Complications

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    Carrie K Gomez


    Full Text Available Objective: The purpose of this study is to identify early computed tomography findings around the driveline which would predict mediastinal or left ventricular assist device (LVAD pocket abscess formation. Materials and Methods: A retrospective analysis was performed on 128 LVAD recipients between January 2007 and December 2011. Infectious complications were subdivided into those affecting the driveline and those resulting in abscess formation either around the LVAD pump or mediastinum. The size and location of infiltrative changes surrounding the driveline were used to predict infection propagation resulting in abscess. Results: Of the 128 patients, 49 (38.3% patients developed driveline infections and 24 (18.8% patients developed abscess. 87.5% patients who developed abscess had a preceding driveline infection. The mean time from driveline infection to the development of pump pocket abscess was approximately 7 months. In addition, patients with abscess in the pump pocket or mediastinum had preceding infiltrative changes surrounding the driveline ≥14 mm (P = 0.0001. A preperitoneal location and size of infiltrative changes ≥14 mm were correlated with a higher likelihood of abscess formation (P = 0.0002. Conclusion: Our study demonstrates the predictive value of infection/infiltrative changes around the driveline, which increases the risk for abscess formation in the LVAD pump pocket and/or in the mediastinum.

  19. Impact of Vice President Cheney on public interest in left ventricular assist devices and heart transplantation. (United States)

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


    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.

  20. Effects of Sevoflurane and Propofol on Organ Blood Flow in Left Ventricular Assist Devices in Pigs

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    Paloma Morillas-Sendín


    Full Text Available The aim of this study was to assess the effect of sevoflurane and propofol on organ blood flow in a porcine model with a left ventricular assist device (LVAD. Ten healthy minipigs were divided into 2 groups (5 per group according to the anesthetic received (sevoflurane or propofol. A Biomedicus centrifugal pump was implanted. Organ blood flow (measured using colored microspheres, markers of tissue injury, and hemodynamic parameters were assessed at baseline (pump off and after 30 minutes of partial support. Blood flow was significantly higher in the brain (both frontal lobes, heart (both ventricles, and liver after 30 minutes in the sevoflurane group, although no significant differences were recorded for the lung, kidney, or ileum. Serum levels of alanine aminotransferase and total bilirubin were significantly higher after 30 minutes in the propofol group, although no significant differences were detected between the groups for other parameters of liver function, kidney function, or lactic acid levels. The hemodynamic parameters were similar in both groups. We demonstrated that, compared with propofol, sevoflurane increases blood flow in the brain, liver, and heart after implantation of an LVAD under conditions of partial support.

  1. Elevation of procalcitonin after implantation of an interventional lung assist device in critically ill patients. (United States)

    Kott, Matthias; Bewig, Burkhard; Zick, Günther; Schaedler, Dirk; Becher, Tobias; Frerichs, Inéz; Weiler, Norbert


    A pumpless interventional arteriovenous lung assist device (iLA) facilitates the removal of carbon dioxide from the blood and is used as part of the lung-protective ventilation strategy in patients with acute respiratory distress syndrome (ARDS). In case of bacterial infection, delayed antimicrobial therapy increases the mortality in this group of high-risk critically ill patients, whereas overtreatment promotes bacterial resistance and leads to increased drug toxicity and costs. Besides clinical signs and symptoms, antimicrobial treatment is based on the kinetics of biomarkers such as procalcitonin (PCT). We hereby report an up to 10-fold increase in PCT serum concentrations in four mechanically ventilated patients with ARDS detected within 12-20 hours after iLA implantation in the absence of any infection. Procalcitonin concentrations returned to nearly baseline values in all patients on the fourth day after iLA implantation. We discuss the possible mechanisms of PCT induction in this specific patient population and recommend the onset of antibiotics administration after iLA implantation to be carefully considered in the context of other clinical findings and not solely based on the PCT kinetics. Repeated PCT measurements in short time intervals should be performed in these patients.

  2. Evaluation of a morphological filter in mean cardiac output determination: application to left ventricular assist devices. (United States)

    Stevens, Michael Charles; Bradley, Andrew P; Wilson, Stephen J; Mason, David Glen


    A morphological filter (MF) is presented for the determination of beat-to-beat mean rotary left ventricular assist device (LVAD) flow rate, measured using an implanted flow probe. The performance of this non-linear filter was assessed using LVAD flow rate (QLVAD) data sets obtained from in silico and in vivo sources. The MF was compared with a third-order Butterworth filter (BWF) and a 10-s moving average filter (MAF). Performance was assessed by calculating the response time and steady state error across a range of heart rates and levels of noise. The response time of the MF was 3.5 times faster than the MAF, 0.5 s slower than the BWF, and had a steady state error of 2.61 %. It completely removed pulsatile signal components caused by residual ventricular function, and tracked sharp transient changes in QLVAD better than the BWF. The use of a two-stage MF improved the noise immunity compared to the single-stage MF. This study showed that the good performance characteristics of the non-linear MF make it a more suitable candidate for embedded real-time processing of QLVAD than linear filters.

  3. Direct cardiac potential trigger for chronic control of a ventricular assist device. (United States)

    Kitamura, M; Hanzawa, K; Aoki, K; Saitoh, M; Hayashi, J


    As a new trigger method for chronic drive control of a ventricular assist device (VAD), a direct cardiac potential trigger was assessed under various conditions in a chronic experimental model. A pneumatic pulsatile VAD was implanted as circulatory support between the left ventricular apex and the ascending aorta in 12 adult pigs. Hemodynamic parameters and pump output were continuously monitored. Two tips of a bipolar electrode were set on the RV anterior wall and the LV posterior wall for recording direct cardiac potential. Counterpulsation drive of the VAD was applied by using the R wave in a standard electrocardiogram (ECG) or the direct cardiac potential as an ECG trigger. As special conditions, various artifacts on ECG, electromusculogram, arrhythmia, irregular ventilation, and passive vibration (simulation of exercise) were set for assessing the ECG trigger modes. Artifacts of irregular ventilation and passive vibration made the drive control poor using a standard ECG trigger. In contrast, the direct cardiac potential trigger maintained the counterpulsation control of the VAD well in all conditions of this study, and was a safe and reliable support for the native heart. It also supported animals for up to 48 hours after operation. The above results suggested that the direct cardiac potential trigger might be useful for monitoring native heart beats and adjusting the support cycle to the native heart cycle as a chronic control method for various VADs.

  4. [Treatment of advanced heart failure in women: heart transplantation and ventricular assist devices]. (United States)

    Cipriani, Manlio; Macera, Francesca; Verde, Alessandro; Bruschi, Giuseppe; del Medico, Marta; Oliva, Fabrizio; Martinelli, Luigi; Frigerio, Maria


    Women candidates for heart transplantation are definitely less than men, just 20% of all patients transplanted; even in the INTERMACS registry they represent only 21% of all ventricular assist devices (VAD) implanted. The reasons for this big difference are discussed in this article. Why women are less frequently assessed for unconventional therapies? Are they sicker or just less regarded? Our experience and the literature show us clear epidemiological, clinical and treatment differences that could lead to a lower prevalence of end-stage disease in women of an age suitable for unconventional therapies. Once on the transplant list, women wait less than men for a heart transplant, because they present with more severe disease, have a lower body mass index and undergo less VAD implants. After transplantation women's survival is comparable to men's, although they usually complain of a lower quality of life. Females receive less often a VAD than men. The main reasons for this include presentation with advanced heart failure at an older age than men, worse outcomes related to small body surface area, and lower survival rates on VAD when implanted as bridge to heart transplantation.

  5. Green Small Cell Operation of Ultra-Dense Networks Using Device Assistance

    Directory of Open Access Journals (Sweden)

    Gilsoo Lee


    Full Text Available As higher performance is demanded in 5G networks, energy consumption in wireless networks increases along with the advances of various technologies, so enhancing energy efficiency also becomes an important goal to implement 5G wireless networks. In this paper, we study the energy efficiency maximization problem focused on finding a suitable set of turned-on small cell access points (APs. Finding the suitable on/off states of APs is challenging since the APs can be deployed by users while centralized network planning is not always possible. Therefore, when APs in small cells are randomly deployed and thus redundant in many cases, a mechanism of dynamic AP turning-on/off is required. We propose a device-assisted framework that exploits feedback messages from the user equipment (UE. To solve the problem, we apply an optimization method using belief propagation (BP on a factor graph. Then, we propose a family of online algorithms inspired by BP, called DANCE, that requires low computational complexity. We perform numerical simulations, and the extensive simulations confirm that BP enhances energy efficiency significantly. Furthermore, simple, but practical DANCE exhibits close performance to BP and also better performance than other popular existing methods. Specifically, in a small-sized network, BP enhances energy efficiency 129%. Furthermore, in ultra-dense networks, DANCE algorithms successfully achieve orders of magnitude higher energy efficiency than that of the baseline.

  6. Objective Quality and Intelligibility Prediction for Users of Assistive Listening Devices (United States)

    Falk, Tiago H.; Parsa, Vijay; Santos, João F.; Arehart, Kathryn; Hazrati, Oldooz; Huber, Rainer; Kates, James M.; Scollie, Susan


    This article presents an overview of twelve existing objective speech quality and intelligibility prediction tools. Two classes of algorithms are presented, namely intrusive and non-intrusive, with the former requiring the use of a reference signal, while the latter does not. Investigated metrics include both those developed for normal hearing listeners, as well as those tailored particularly for hearing impaired (HI) listeners who are users of assistive listening devices (i.e., hearing aids, HAs, and cochlear implants, CIs). Representative examples of those optimized for HI listeners include the speech-to-reverberation modulation energy ratio, tailored to hearing aids (SRMR-HA) and to cochlear implants (SRMR-CI); the modulation spectrum area (ModA); the hearing aid speech quality (HASQI) and perception indices (HASPI); and the PErception MOdel - hearing impairment quality (PEMO-Q-HI). The objective metrics are tested on three subjectively-rated speech datasets covering reverberation-alone, noise-alone, and reverberation-plus-noise degradation conditions, as well as degradations resultant from nonlinear frequency compression and different speech enhancement strategies. The advantages and limitations of each measure are highlighted and recommendations are given for suggested uses of the different tools under specific environmental and processing conditions. PMID:26052190

  7. Reproduction of continuous flow left ventricular assist device experimental data by means of a hybrid cardiovascular model with baroreflex control. (United States)

    Fresiello, Libera; Zieliński, Krzysztof; Jacobs, Steven; Di Molfetta, Arianna; Pałko, Krzysztof Jakub; Bernini, Fabio; Martin, Michael; Claus, Piet; Ferrari, Gianfranco; Trivella, Maria Giovanna; Górczyńska, Krystyna; Darowski, Marek; Meyns, Bart; Kozarski, Maciej


    Long-term mechanical circulatory assistance opened new problems in ventricular assist device-patient interaction, especially in relation to autonomic controls. Modeling studies, based on adequate models, could be a feasible approach of investigation. The aim of this work is the exploitation of a hybrid (hydronumerical) cardiovascular simulator to reproduce and analyze in vivo experimental data acquired during a continuous flow left ventricular assistance. The hybrid cardiovascular simulator embeds three submodels: a computational cardiovascular submodel, a computational baroreflex submodel, and a hydronumerical interface submodel. The last one comprises two impedance transformers playing the role of physical interfaces able to provide a hydraulic connection with specific cardiovascular sites (in this article, the left atrium and the ascending/descending aorta). The impedance transformers are used to connect a continuous flow pump for partial left ventricular support (Synergy Micropump, CircuLite, Inc., Saddlebrooke, NJ, USA) to the hybrid cardiovascular simulator. Data collected from five animals in physiological, pathological, and assisted conditions were reproduced using the hybrid cardiovascular simulator. All parameters useful to characterize and tune the hybrid cardiovascular simulator to a specific hemodynamic condition were extracted from experimental data. Results show that the simulator is able to reproduce animal-specific hemodynamic status both in physiological and pathological conditions, to reproduce cardiovascular left ventricular assist device (LVAD) interaction and the progressive unloading of the left ventricle for different pump speeds, and to investigate the effects of the LVAD on baroreflex activity. Results in chronic heart failure conditions show that an increment of LVAD speed from 20 000 to 22 000 rpm provokes a decrement of left ventricular flow of 35% (from 2 to 1.3 L/min). Thanks to its flexibility and modular structure, the

  8. A new design approach of user-centered design on a personal assistive bathing device for hemiplegia. (United States)

    Ma, Min-Yuan; Wu, Fong-Gong; Chang, Ro-Han


    To move closer to the goal of independent living for stroke patients with hemiplegia, this study is to design an assistive bathing device approached from a User-Centred Design (UCD). Based on User-Centred Design methodology, a design process is adopted for this study. Observation and evaluation results from a Usability Context Analysis (UCA) are employed to improve the strengths, weaknesses, opportunities and threats (SWOT) and the matrix for matching the environmental threats and opportunities with company's weaknesses and especially it's strengths (TOWS), resulting in two assistive device (AD) design methods named AD-SWOT and AD-TOWS. Therefore, a new assistive device design process (AD-Design process) is proposed. A case study of stroke patients is conducted to practically apply the AD-Design process to the design of assistive bathing devices for stroke patients. By using the AD-Design process, three design concept orientations (AD-SO, AD-ST, AD-WO) were found for design concept generating from AD-TOWS. Four concepts for AD were decided and designed by the viewpoint of UCD. Finally, three ADs for bathing were tested by user-based assessment. And results showed the devices can help individuals clean case's body parts, such as case's backs and armpits that they were previously unable to clean independently. AD-design process could help a product designer to generate suitable design approaching from UCD. In this study, three ADs (Back Cleaning Board, Feet Cleaning and Single-Sided Elastic Bathing Belt) were designed for a stroke patient's individual bathing.

  9. Acoustic puncture assist device versus loss of resistance technique for epidural space identification

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    Amit Kumar Mittal


    Full Text Available Background and Aims: The conventional techniques of epidural space (EDS identification based on loss of resistance (LOR have a higher chance of complications, patchy analgesia and epidural failure, which can be minimised by objective confirmation of space before catheter placement. Acoustic puncture assist device (APAD technique objectively confirms EDS, thus enhancing success, with lesser complications. This study was planned with the objective to evaluate the APAD technique and compare it to LOR technique for EDS identification and its correlation with ultrasound guided EDS depth. Methods: In this prospective study, the lumbar vertebral spaces were scanned by the ultrasound for measuring depth of the EDS and later correlated with procedural depth measured by either of the technique (APAD or LOR. The data were subjected to descriptive statistics; the concordance correlation coefficient and Bland-Altman analysis with 95% confidence limits. Results: Acoustic dip in pitch and descent in pressure tracing on EDS localisation was observed among the patients of APAD group. Analysis of concordance correlation between the ultrasonography (USG depth and APAD or LOR depth was significant (r ≥ 0.97 in both groups. Bland-Altman analysis revealed a mean difference of 0.171cm in group APAD and 0.154 cm in group LOR. The 95% limits of agreement for the difference between the two measurements were − 0.569 and 0.226 cm in APAD and − 0.530 to 0.222 cm in LOR group. Conclusion: We found APAD to be a precise tool for objective localisation of the EDS, co-relating well with the pre-procedural USG depth of EDS.

  10. Acoustic puncture assist device versus loss of resistance technique for epidural space identification. (United States)

    Mittal, Amit Kumar; Goel, Nitesh; Chowdhury, Itee; Shah, Shagun Bhatia; Singh, Brijesh Pratap; Jakhar, Pradeep


    The conventional techniques of epidural space (EDS) identification based on loss of resistance (LOR) have a higher chance of complications, patchy analgesia and epidural failure, which can be minimised by objective confirmation of space before catheter placement. Acoustic puncture assist device (APAD) technique objectively confirms EDS, thus enhancing success, with lesser complications. This study was planned with the objective to evaluate the APAD technique and compare it to LOR technique for EDS identification and its correlation with ultrasound guided EDS depth. In this prospective study, the lumbar vertebral spaces were scanned by the ultrasound for measuring depth of the EDS and later correlated with procedural depth measured by either of the technique (APAD or LOR). The data were subjected to descriptive statistics; the concordance correlation coefficient and Bland-Altman analysis with 95% confidence limits. Acoustic dip in pitch and descent in pressure tracing on EDS localisation was observed among the patients of APAD group. Analysis of concordance correlation between the ultrasonography (USG) depth and APAD or LOR depth was significant (r ≥ 0.97 in both groups). Bland-Altman analysis revealed a mean difference of 0.171cm in group APAD and 0.154 cm in group LOR. The 95% limits of agreement for the difference between the two measurements were - 0.569 and 0.226 cm in APAD and - 0.530 to 0.222 cm in LOR group. We found APAD to be a precise tool for objective localisation of the EDS, co-relating well with the pre-procedural USG depth of EDS.

  11. Evaluation of Physiological Control Systems for Rotary Left Ventricular Assist Devices: An In-Vitro Study. (United States)

    Pauls, Jo P; Stevens, Michael C; Bartnikowski, Nicole; Fraser, John F; Gregory, Shaun D; Tansley, Geoff


    Rotary left ventricular assist devices (LVADs) show weaker response to preload and greater response to afterload than the native heart. This may lead to ventricular suction or pulmonary congestion, which can be deleterious to the patient's recovery. A physiological control system which optimizes responsiveness of LVADs may reduce adverse events. This study compared eight physiological control systems for LVAD support against constant speed mode. Pulmonary (PVR) and systemic (SVR) vascular resistance changes, a passive postural change and exercise were simulated in a mock circulation loop to evaluate the controller's ability to prevent suction and congestion and to increase exercise capacity. Three active and one passive control systems prevented ventricular suction at high PVR (500 dyne s cm(-5)) and low SVR (600 dyne s cm(-5)) by decreasing LVAD speed (by 200-515 rpm) and by increasing LVAD inflow cannula resistance (up to 1000 dyne s cm(-5)) respectively. These controllers increased LVAD preload sensitivity (to 0.196-2.415 L min(-1) mmHg(-1)) compared to the other control systems and constant speed mode (0.039-0.069 L min(-1) mmHg(-1)). The same three active controllers increased pump speed (600-800 rpm) and thus LVAD flow by 4.5 L min(-1) during exercise which increased exercise capacity. Physiological control systems that prevent adverse events and/or increase exercise capacity may help improve LVAD patient conditions.

  12. Nutrition Assessment With Indirect Calorimetry in Patients Evaluated for Left Ventricular Assist Device Implantation. (United States)

    Yost, Gardner; Gregory, Mary; Bhat, Geetha


    Malnutrition is known to negatively impact the clinical course of advanced heart failure and is associated with increased mortality following left ventricular assist device (LVAD) implantation. Appropriate assessment of nutrition requirements in these patients is critical in their clinical care, yet there has been little discussion on how to best determine resting energy expenditure (REE) in the hospital setting. We investigated the use of indirect calorimetry in a group of patients with advanced heart failure. Results from preoperative indirect calorimetry testing in 98 patients undergoing evaluation for LVAD candidacy were collected. REE was compared with 10 predictive equations that estimated caloric need based on a range of patient-specific demographic and clinical variables. This study enrolled 22 female and 76 male patients with a mean age of 59.4 ± 12.5 years, body mass index of 29.6 ± 6.0 kg/m(2), and ejection fraction of 19.4 ± 6.6%. The average REE by indirect calorimetry in this group was 1610.0 ± 612.7 kcal/d. All predictive equations significantly overestimated REE. However, those equations intended for use in the critically ill demonstrated the greatest accuracy, with the Brandi equation achieving both the highest correlation (r = 0.605, P calorimetry may be reliably and safely used to determine caloric requirements in patients with advanced heart failure. The use of predictive equations based on demographic and clinical parameters appears to generate inaccurate estimations of REE in these patients. However, equations designed for use in critically ill patients better estimate nutrition requirements than those designed for healthy individuals. © 2015 American Society for Parenteral and Enteral Nutrition.

  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. The perioperative management of patients with left ventricular assist devices undergoing noncardiac surgery. (United States)

    Barbara, David W; Wetzel, David R; Pulido, Juan N; Pershing, Bryan S; Park, Soon J; Stulak, John M; Zietlow, Scott P; Morris, David S; Boilson, Barry A; Mauermann, William J


    To describe the perioperative management of patients with left ventricular assist devices (LVADs) who require general anesthesia while undergoing noncardiac surgery (NCS) at a single, large tertiary referral center. Electronic medical records from September 2, 2005, through May 31, 2012, were retrospectively reviewed to evaluate the perioperative management and outcomes in LVAD patients undergoing NCS. Patients were included only if they required a general anesthetic and had previously been discharged from the hospital after initial LVAD implantation. Thirty-three patients with LVADs underwent general anesthesia for 67 noncardiac operations. The mean ± SD time from LVAD implantation to NCS was 317 ± 349 days. All but 1 patient had axial flow LVADs. Anticoagulation or antiplatelet agents were present within 7 days before NCS in 49 procedures (73%) and reversed in 32 of 49 (65%). No perioperative thrombotic complications related to anticoagulation or antiplatelet reversal were noted. Red blood cell, fresh frozen plasma, and platelet transfusions were administered during 10, 6, and 4 operations, respectively. The only intraoperative complication was surgical bleeding. Postoperative complications were present in 12 patients after NCS and were mainly composed of bleeding. Three patients died within 30 days of NCS, with the causes of death not attributed to NCS. Patients with LVAD safely underwent NCS in a multidisciplinary setting that included preoperative optimization by cardiologists familiar with LVADs when feasible. Anticoagulation or antiplatelet agents were present preoperatively in most patients with LVADs and were safely reversed when necessary for NCS. The relatively high occurrence of postoperative bleeding is consistent with previous series. Copyright © 2013 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  15. Prevalence of Cerebral Microbleeds in Patients With Continuous-Flow Left Ventricular Assist Devices. (United States)

    Yoshioka, Daisuke; Okazaki, Shuhei; Toda, Koichi; Murase, Sho; Saito, Shunsuke; Domae, Keitaro; Miyagawa, Shigeru; Yoshikawa, Yasushi; Daimon, Takashi; Sakaguchi, Manabu; Sawa, Yoshiki


    The prevalence of cerebral microbleeds (CMBs) in gradient echo T2*-weighted brain MRI has a positive correlation with hemorrhagic stroke incidence. However, the prevalence of CMBs in patients with left ventricular assist devices (LVADs) has not been evaluated. We evaluated the prevalence of CMBs and the relationship with hemorrhagic stroke incidence in patients with LVADs. We analyzed results from brain MRI in prospective examinations of 35 consecutive patients who had undergone LVAD explantation for heart transplantation or recovery since 2011. The number and distribution of CMBs were counted, then the relationship between baseline characteristics and adverse events during LVAD support were analyzed. The mean age was 37.7±12.4 years and the mean LVAD duration was 2.43±1.08 years. Thirty-four (97%) patients had at least one CMB. Nine (26%) developed hemorrhagic stroke during LVAD support, and patients with hemorrhagic stroke had a significantly greater number of CMBs compared with patients without hemorrhagic stroke (5 [interquartile range (IQR), 4-7] versus 9 [IQR, 5-23]; odds ratio 1.14 [95% Confidence Interval (CI), 1.02-1.32], P=0.05). There was no significant relationship between age, LVAD support duration, or systolic blood pressure during LVAD. However, patients who had at least one episode of bacteremia (9 [IQR, 4-16] versus 5 [IQR, 3-7], P=0.06) and pump pocket infection (14 [IQR, 4-27] versus 5 [IQR, 3-7], P=0.08) showed a trend toward a greater number of CMBs than patients without bacteremia. Thirty-four (97%) patients with continuous-flow LVAD had at least one CMB, and the number of CMBs were more prevalent in patients with hemorrhagic stroke and in patients with LVAD-related infection. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  16. Monitoring hemostasis parameters in left ventricular assist device recipients – a preliminary report (United States)

    Kaczmarski, Jacek; Pacholewicz, Jerzy; Zakliczyński, Michał; Gąsior, Mariusz; Zembala, Marian


    Introduction Mechanical circulatory support (MCS) therapy is associated with the improvement of long-term prognosis in patients with end-stage heart failure. For years it has been used as a bridge to transplant. However, more recently it is even being used as a destination therapy. Recently, clinicians have identified common MCS therapy-associated complications: pump thrombosis, bleeding, and hemolysis. These complications are very challenging with regard to both diagnosis and management. Aim To determine time-dependant changes of selected hemostasis/coagulation parameters in patients with end-stage heart failure treated with MCS and antithrombotic therapy. Material and methods Sixteen patients with end-stage heart failure on left ventricular assist device (LVAD) were followed for 6 weeks (six blood samples for each patient). Every week an extended hemostasis panel was assessed, including activated partial thromboplastin time, prothrombin time, international normalized ratio, von Willebrand factor (vWF) activity, factor VIII activity, fibrinogen level, D-dimer, platelet response to arachidonic acid (ASPI test) and adenosine diphosphate (ADP test), thrombin receptor activating peptide-6 (TRAP test) and collagen (COL test). Results The study population comprised 16 men. The median time from LVAD implantation was 120 days (100–150 days). During the study period the D-dimer and fibrinogen concentrations were elevated but remained similar throughout all six measurements. Meanwhile factor VIII and vWF activities were elevated in the first two measurements and then subsequently declined. Inhibition of platelet aggregation was greater early after LVAD implantation. During subsequent weeks the inhibition of platelet aggregation was less pronounced. No patient developed any bleeding or thrombo-embolic event during the study period. Conclusions Patients on MCS therapy demonstrate significant time-dependant changes in hemostasis parameters (both in the coagulation system and

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


    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.

  18. Left ventricular assist device effects on metabolic substrates in the failing heart.

    Directory of Open Access Journals (Sweden)

    Lindsay B Weitzel

    Full Text Available BACKGROUND: Heart failure patients have inadequate nutritional intake and alterations in metabolism contributing to an overall energy depleted state. Left ventricular assist device (LVAD support is a common and successful intervention in patients with end-stage heart failure. LVAD support leads to alterations in cardiac output, functional status, neurohormonal activity and transcriptional profiles but the effects of LVADs on myocardial metabolism are unknown. This study set out to measure cardiac metabolites in non-failing hearts, failing hearts, and hearts post-LVAD support. METHODS: The study population consisted of 8 non-ischemic failing (at LVAD implant and 8 post-LVAD hearts, plus 8 non-failing hearts obtained from the tissue bank at the University of Colorado. NMR spectroscopy was utilized to evaluate differences in myocardial energy substrates. Paired and non-paired t-tests were used to determine differences between the appropriate groups. RESULTS: Glucose and lactate values both decreased from non-failing to failing hearts and increased again significantly in the (paired post-LVAD hearts. Glutamine, alanine, and aromatic amino acids decreased from non-failing to failing hearts and did not change significantly post-LVAD. Total creatine and succinate decreased from non-failing to failing hearts and did not change significantly post-LVAD. DISCUSSION: Measured metabolites related to glucose metabolism are diminished in failing hearts, but recovered their values post-LVAD. This differed from the amino acid levels, which decreased in heart failure but did not recover following LVAD. Creatine and the citric acid cycle intermediate succinate followed a similar pattern as the amino acid levels.

  19. Five-week use of a monopivot centrifugal blood pump as a right ventricular assist device in severe dilated cardiomyopathy. (United States)

    Inoue, Takamichi; Kitamura, Tadashi; Torii, Shinzo; Hanayama, Naoji; Oka, Norihiko; Itatani, Keiichi; Tomoyasu, Takahiro; Irisawa, Yusuke; Shibata, Miyuki; Hayashi, Hidenori; Ono, Minoru; Miyaji, Kagami


    Right heart failure is a critical complication in patients requiring mechanical ventricular support. However, it is often difficult to provide adequate right ventricular support in the acute phase. A 41-year-old woman diagnosed with dilated cardiomyopathy with severe right heart failure underwent implantation of a paracorporeal pulsatile left ventricular assist device (LVAD, Nipro Corporation, Tokyo, Japan) and a MERA monopivot centrifugal pump (Senko Medical Instrument Manufacturing Co., Ltd., Tokyo, Japan) as a right ventricular assist device (RVAD). The patient developed ischemic enteritis 3 weeks after surgery, necessitating fasting and reversal of anticoagulation therapy. A target international normalized ratio of 1.5 was selected, and aspirin administration was discontinued. Following recovery without thromboembolic events, the patient failed the RVAD discontinuation test. Five weeks after surgery, the monopivot centrifugal pump was exchanged for a pulsatile pump. No thrombus was evident on the centrifugal pump. The patient was undergoing cardiac rehabilitation at the time of this writing and awaiting heart transplantation.

  20. 台湾地区辅助器具服务%Service of Assistive Devices in Taiwan

    Institute of Scientific and Technical Information of China (English)



    台湾建有医保、荣军、劳动就业、教育、体育、卫生福利等六个行政体系为残疾人提供辅具服务;建立了辅具的服务网络、补助目录、补助标准和评估制度。%Six administrative systems are established to provide assistive devices for the person with disability in Taiwan, such as medi-cal insurance, disabled soldier, labour, education, sports, health and welfare, etc. Service network, subsidies directory, subsidies standards and evaluation system of assistive devices are also set up.

  1. Enhancing the quality of life and preserving independence for target needs populations through integration of assistive technology devices. (United States)

    Muncert, Eric S; Bickford, Steven A; Guzic, Brenda L; Demuth, Barbara R; Bapat, Ashok R; Roberts, Jay B


    Telehealth Test Bed-Quality of Life Studies is a research study investigating, testing, evaluating, and demonstrating technologies that have the potential to improve the quality of life for target populations, such as warriors in transition, veterans, individuals with physical and mental disabilities, and adults age 65 and older, who may require assistive technology devices to aid in maintaining or improving their quality of life. Thousands of soldiers who fought in Operation Iraqi Freedom and Operation Enduring Freedom have been wounded in action or have sustained injuries from noncombat accidents. Many of these injuries affecting military populations, as well as the general public, have resulted in amputations, traumatic brain injuries, and other physical or mental impairments. Depending on the severity of the injury, assistive technologies may be temporarily needed, or as a long-term solution, to regain and maintain normal daily functions. Saint Francis University's Center of Excellence for Remote and Medically Under-Served Areas developed an evaluation matrix comparing assistive technologies to identify devices that will improve or maintain the quality of life for these target populations. The integration of telehealth and telerehabilitation applications into patients' daily lives was examined to help improve home rehabilitation via access to healthcare specialties in rural and medically underserved settings. Researchers identified and tested assistive technology devices to be included in a self-sufficient living environment. The continuation of this research involves recruiting individuals to test and evaluate the functions of these commercially available technologies and to complete data collection surveys and questionnaires. The results are useful in selecting devices that will enhance or extend the quality of life of the target populations.

  2. A new user-centered design approach: a hair washing assistive device design for users with shoulder mobility restriction. (United States)

    Wu, Fong-Gong; Ma, Min-Yuan; Chang, Ro-Han


    This study utilized a user-centered design approach as the foundation for a new Assistive Device (AD) design process. Observation and evaluation results from a Usability Context Analysis (UCA) was used to improve the analysis of Strengths, Weaknesses, Opportunities and Threats (SWOT Analysis) and the matrix of Threats, Opportunities, Weaknesses, and Strengths (TOWS matrix), resulting in two assistive device design methods named AD-SWOT and AD-TOWS. Thus, an AD-design process, tailored for designing assistive devices, was both established and tested. Owing to the information gained from using the design processes and evaluating product efficiency with various cases in the early part of the research, it was decided to use the AD-design process for the entire design process. Using this process, an adjustable hair washer for physically disabled individuals to wash their hair using normal postures was developed. Furthermore, the method derived in this study can also be applied to users suffering from single-sided shoulder-joint mobility disabilities, such as frontal flexion, scapular plan elevation, and restricted abductors.

  3. An eye-tracking assistive device improves the quality of life for ALS patients and reduces the caregivers' burden. (United States)

    Hwang, Chi-Shin; Weng, Ho-Hsiu; Wang, Li-Fen; Tsai, Chon-Haw; Chang, Hao-Teng


    Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease. In some cases, patients with ALS retain a normal level of consciousness but disease progression eventually results in generalized paralysis, which first impedes and then prevents oral communication. This communication obstacle can generate a great deal of stress for the patient, family, and caregiver. Here the authors ask whether the use of an eye-tracking assistive device can improve quality of life for ALS patients and relieves burden of their primary caregivers. Subjects were divided into two groups depending on whether they used (n = 10) or did not use (n = 10) an eye-tracking assistive device. The authors assessed patients' quality of life and severity of depression using the ALS Specific Quality of Life Instrument-Revised and the Taiwanese Depression Questionnaire, respectively. The Caregiver Burden Scale was used to assess the burden on caregivers. Our study shows that the eye-tracking assistive device significantly improved patients' quality of life, as compared with patients in the nonuser group (p improvement of patient's autonomy and more effective communication between patient and caregiver.

  4. 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


    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.

  5. Structural design of a newly developed pediatric circulatory assist device for Fontan circulation by using shape memory alloy fiber. (United States)

    Shiraishi, Y; Sugai, T K; Tanaka, A; Yoshizawa, M; Yambe, T; Yamada, A; Omran, M H; Shiga, T; Kitano, T; Kamiya, K; Mochizuki, S; Miura, H; Homma, D; Yamagishi, M


    Total cavopulmonary connection (TCPC) is commonly applied for the surgical treatment of congenital heart disease such as single ventricle in pediatric patients. Patients with no ventricle in pulmonary circulation are treated along with Fontan algorithm, in which the systemic venous return is diverted directly to the pulmonary artery without passing through subpulmonary ventricle. In order to promote the pulmonary circulation after Fontan procedure, we developed a newly designed pulmonary circulatory assist device by using shape memory alloy fibers. We developed a pulmonary circulatory assist device as a non-blood contacting mechanical support system in pediatric patients with TCPC. The device has been designed to be installed like a cuff around the ePTFE TCPC conduit, which can contract from outside. We employed a covalent type functional anisotropic shape memory alloy fiber (Biometal, Toki Corporation, Tokyo Japan) as a servo actuator of the pulmonary circulatory assist device. The diameter of this fiber was 100 microns, and its contractile frequency was 2-3 Hz. Heat generation with electric current contracts these fibers and the conduit. The maximum contraction ratio of this fiber is about 7% in length. In order to extend its contractile ratio, we fabricated and installed mechanical structural units to control the length of fibers. In this study, we examined basic contractile functions of the device in the mock system. As a result, the internal pressure of the conduit increased to 63 mmHg by the mechanical contraction under the condition of 400 msec-current supply in the mock examination with the overflow tank of 10 mmHg loading.

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

  7. The physiological effect of a 'climb assist' device on vertical ladder climbing. (United States)

    Barron, Peter James; Burgess, Katherine; Cooper, Kay; Stewart, Arthur D


    'Climb assist' claims to reduce strain when climbing ladders; however, no research has yet substantiated this. The purpose of this study was to assess the physiological and psychophysical effects of climb assist on 30 m ladder climbing at a minimum acceptable speed. Eight participants (six male and two female) climbed a 30 m ladder at 24 rungs per minute with and without climb assist, and were monitored for heart rate (HR), [Formula: see text]O2 and rate of perceived exertion (RPE). All three variables decreased significantly (p climb assist with [Formula: see text]O2 decreasing by 22.5%, HR by 14.8% and RPE decreasing by a mean of 2.3 units on the 10-point Borg scale. When descending the ladder [Formula: see text]O2 decreased by a mean of 42% compared to that ascending. At the minimal acceptable climbing speed climb assist decreases the physiological strain on climbers, as demonstrated by reduced [Formula: see text]O2, HR and perceived exertion. Practitioner Summary: 'Climb assist' systems claim to reduce strain when climbing, however; no research has yet been published to substantiate this. A crossover study compared [Formula: see text]O2, HR and RPE at a minimal acceptable climbing speed with and without climb assist. Climb assist significantly reduced all variables confirming it reduces strain when climbing.

  8. Ventricular Assist Devices and Increased Blood Product Utilization for Cardiac Transplantation (United States)

    Stone, Matthew L.; LaPar, Damien J.; Benrashid, Ehsan; Scalzo, David C.; Ailawadi, Gorav; Kron, Irving L.; Bergin, James D.; Blank, Randal S.; Kern, John A.


    Background and Aim of Study The purpose of this study was to examine whether blood product utilization, one-year cell-mediated rejection rates, and mid-term survival significantly differ for ventricular assist device (VAD patients compared to non-VAD (NVAD) patients following cardiac transplantation. Methods From July 2004 to August 2011, 79 patients underwent cardiac transplantation at a single institution. Following exclusion of patients bridged to transplantation with VADs other than the HeartMate II® LVAD (n = 10), patients were stratified by VAD presence at transplantation: VAD patients (n = 35, age: 54.0 [48.0–59.0] years) vs. NVAD patients (n = 34, age: 52.5 [42.8–59.3] years). The primary outcomes of interest were blood product transfusion requirements, one-year cell-mediated rejection rates, and mid-term survival post-transplantation. Results Preoperative patient characteristics were similar for VAD and NVAD patients. NVAD patients presented with higher median preoperative creatinine levels compared to VAD patients (1.3 [1.1–1.6] vs. 1.1 [0.9–1.4], p = 0.004). VAD patients accrued higher intraoperative transfusion of all blood products (all p ≤ 0.001) compared to NVAD patients. The incidence of clinically significant cell-mediated rejection within the first posttransplant year was higher in VAD compared to NVAD patients (66.7% vs. 33.3%, p = 0.02). During a median follow-up period of 3.2 (2.0, 6.3) years, VAD patients demonstrated an increased postoperative mortality that did not reach statistical significance (20.0% vs. 8.8%, p = 0.20). Conclusions During the initial era as a bridge to transplantation, the HeartMate II® LVAD significantly increased blood product utilization and one-year cell-mediated rejection rates for cardiac transplantation. Further study is warranted to optimize anticoagulation strategies and to define causal relationships between these factors for the current era of cardiac transplantation. PMID:25529999

  9. Fundus fluorescein angiographic findings in patients who underwent ventricular assist device implantation. (United States)

    Ozturk, Taylan; Nalcaci, Serhad; Ozturk, Pelin; Engin, Cagatay; Yagdi, Tahir; Akkin, Cezmi; Ozbaran, Mustafa


    Disruption of microcirculation in various tissues as a result of deformed blood rheology due to ventricular assist device (VAD) implantation causes novel arteriovenous malformations. Capillary disturbances and related vascular leakage in the retina and choroidea may also be seen in patients supported by VADs. We aimed to evaluate retinal vasculature deteriorations after VAD implantation. The charts of 17 patients who underwent VAD implantation surgery for the treatment of end-stage heart failure were retrospectively reviewed. Eight cases (47.1%) underwent pulsatile pump implantation (Berlin Heart EXCOR, Berlin Heart Mediprodukt GmbH, Berlin, Germany); however, nine cases (52.9%) had continuous-flow pump using centrifugal design (HeartWare, HeartWare Inc., Miramar, FL, USA). Study participants were selected among the patients who had survived with a VAD for at least 6 months, and results of detailed ophthalmologic examinations including optic coherence tomography (OCT) and fundus fluorescein angiography (FA) were documented. All of the 17 patients were male, with a mean age of 48.5 ± 14.8 years (15-67 years). Detailed ophthalmologic examinations including the evaluation of retinal vascular deteriorations via FA were performed at a mean of 11.8 ± 3.7 months of follow-up (6-18 months). Mean best-corrected visual acuity and intraocular pressure were found as logMAR 0.02 ± 0.08 and 14.6 ± 1.9 mm Hg, respectively in the study population. Dilated fundoscopy revealed severe focal arteriolar narrowing in two patients (11.8%), and arteriovenous crossing changes in four patients (23.5%); however, no pathological alteration was present in macular OCT scans. In patients with continuous-flow blood pumps, mean arm-retina circulation time (ARCT) and arteriovenous transit time (AVTT) were found to be 16.8 ± 3.0 and 12.4 ± 6.2 s, respectively; whereas those with pulsatile-flow blood pumps were found to be 17.4 ± 3.6 and 14.0 ± 2.1 s in patients (P=0.526 and P=0

  10. Changes in myocardial collagen content before and after left ventricular assist device application in dilated cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    LIANG Hong 梁红; Roland Hetzer; Johannes Müller; WENG Yu-guo 翁渝国; Gerd Wallukat; FU Ping 付平; LIN Han-sheng 林汉生; Sabina Bartel; Christoph Knosalla; Reinhard Pregla


    Background The purposes of this study were to confirm the changes in myocardial collagen level after left ventricular assist device (LVAD) support in dilated cardiomyopathy (DCM), find the relation between these changes and prognosis, and test a practical method to assess the level of myocardial collagen.Methods Left ventricular samples were collected from DCM patients with different prognosis (transplanted group n=8, weaning group n=10) at the time when the LVADs were implanted and again during cardiac transplantation (n=8). The level of neutral salt soluble collagen (NSC) and acid soluble collagen (ASC) was measured by Sircol collagen assay, and that of total collagen and insoluble collagen (ISC) by quantification of hydroxyproline (Hyp). Serum samples were collected from a portion of these patients (transplanted group, n=6; weaning group n=7) at the time the LVADs were implanted, 1 month after implantation and on explantation. Circulating concentration of carboxy-terminal propeptide of type Ⅰ procollagen (PⅠCP), amino-terminal propeptide of type Ⅰ procollagen (PⅠNP), amino-terminal propeptide of type Ⅲ procollagen (PⅢNP) and type Ⅰ collagen telopeptide (ⅠCTP) were measured by the equilibrium type radioimmunoassay. Results Before LVAD implantation the level of NSC and ISC in the weaning group was higher but ASC in the transplanted group was lower than in the controls (P<0.05). After LVAD support, the level of total collagen was higher, but ASC was also lower in the transplanted group than in the controls (P<0.05). In comparison of the pre- and post-LVAD subgroups of the transplanted and weaning groups, all collagen fraction levels before LVAD implantation were lower in the transplanted group than in the weaning group (P<0.05); but this difference disappeared after LVAD support. Comparison of the pre- and post-LVAD subgroups of the transplanted group showed increased level of NSC and total collagen after LVAD support. The changes of serum peptide

  11. How to treat stage D heart failure? - When to implant left ventricular assist devices in the era of continuous flow pumps?-. (United States)

    Kinugawa, Koichiro


    The new classification of heart failure in the American College of Cardiology/American Heart Association guidelines includes stage D, which is refractory severe heart failure that does not respond to medical or resynchronization therapy. Among the many treatment strategies for stage D heart failure, only heart transplantation and ventricular assist devices have been established as improving prognosis. With the evolution in the mechanics of ventricular assist devices in recent years, the postoperative prognosis has improved, and less sick patients can now be candidates for these devices. In Japan, 2 continuous flow devices have been approved since April 2011, and now is the best time to consider the indications for their use.

  12. The Resonating Arm Exerciser: design and pilot testing of a mechanically passive rehabilitation device that mimics robotic active assistance. (United States)

    Zondervan, Daniel K; Palafox, Lorena; Hernandez, Jorge; Reinkensmeyer, David J


    Robotic arm therapy devices that incorporate actuated assistance can enhance arm recovery, motivate patients to practice, and allow therapists to deliver semi-autonomous training. However, because such devices are often complex and actively apply forces, they have not achieved widespread use in rehabilitation clinics or at home. This paper describes the design and pilot testing of a simple, mechanically passive device that provides robot-like assistance for active arm training using the principle of mechanical resonance. The Resonating Arm Exerciser (RAE) consists of a lever that attaches to the push rim of a wheelchair, a forearm support, and an elastic band that stores energy. Patients push and pull on the lever to roll the wheelchair back and forth by about 20 cm around a neutral position. We performed two separate pilot studies of the device. In the first, we tested whether the predicted resonant properties of RAE amplified a user's arm mobility by comparing his or her active range of motion (AROM) in the device achieved during a single, sustained push and pull to the AROM achieved during rocking. In a second pilot study designed to test the therapeutic potential of the device, eight participants with chronic stroke (35 ± 24 months since injury) and a mean, stable, initial upper extremity Fugl-Meyer (FM) score of 17 ± 8 / 66 exercised with RAE for eight 45 minute sessions over three weeks. The primary outcome measure was the average AROM measured with a tilt sensor during a one minute test, and the secondary outcome measures were the FM score and the visual analog scale for arm pain. In the first pilot study, we found people with a severe motor impairment after stroke intuitively found the resonant frequency of the chair, and the mechanical resonance of RAE amplified their arm AROM by a factor of about 2. In the second pilot study, AROM increased by 66% ± 20% (p = 0.003). The mean FM score increase was 8.5 ± 4 pts (p = 0.009). Subjects did not report


    Dutra, Robson Azevedo; Boscollo, Adriana Cartafina Perez


    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

  14. 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


    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.

  15. The Effectiveness and Safety of Exoskeletons as Assistive and Rehabilitation Devices in the Treatment of Neurologic Gait Disorders in Patients with Spinal Cord Injury: A Systematic Review

    National Research Council Canada - National Science Library

    Fisahn, Christian; Aach, Mirko; Jansen, Oliver; Moisi, Marc; Mayadev, Angeli; Pagarigan, Krystle T; Dettori, Joseph R; Schildhauer, Thomas A


    Study Design Systematic review. Clinical Questions (1) When used as an assistive device, do wearable exoskeletons improve lower extremity function or gait compared with knee-ankle-foot orthoses (KAFOs...

  16. Initial experience with the Impella left ventricular assist device for postcardiotomy cardiogenic shock and unprotected left coronary artery angioplasty in patients with a low left ventricular ejection fraction

    National Research Council Canada - National Science Library

    Bautista-Hernández, Víctor; Gutiérrez, Francisco; Pinar, Eduardo; Gimeno, Juan R; Arribas, José M; García-Puente, Julio; Ray, Victor G; Arcas, Ramón; Valdés, Mariano


    .... Ventricular assist devices have been used to treat patients who suffer from postoperative cardiogenic shock despite use of an intraaortic balloon pump and maximum inotropic support. The Impella pump...

  17. Endoscopic hemostasis with an ultrasonically activated device for hemorrhage from a branch of the maxillary artery during endoscopically assisted reduction of condylar neck fracture. (United States)

    Iwai, Toshinori; Matsui, Yoshiro; Omura, Susumu; Tohnai, Iwai


    We describe here a case in which sudden hemorrhage from a branch of the maxillary artery during endoscopically assisted transoral reduction of condylar neck fracture was successfully controlled by endoscopic hemostasis with an ultrasonically activated device.

  18. A fast building and effective hydraulic pediatric mock circulatory system for the evaluation of a left ventricular assist device. (United States)

    Huang, Feng; Ruan, Xiaodong; Zou, Jun; Qian, Wenwei; Fu, Xin


    A mock circulatory system (MCS) has been proven a useful tool in the development of a ventricular assist device. Nowadays a MCS aimed at the evaluation of pediatric blood pumps, which require many different considerations compared with that of adults, has become an urgent need. This article presents the details on how the dynamic process of the left ventricle, which is described in terms of the pressure-volume loop (P-V loop), and the properties of the circulation such as compliance and resistance are simulated by hydraulic elements. A simple control method is introduced to reproduce the physiological afterload and preload sensitivities of the mock ventricle for the first time. Hemodynamic performance of the system is obtained by medical sensors to validate the similarity of the device to the native cardiovascular system. The actual sensitivities of the mock ventricle are obtained intuitively from the changes of the P-V loops. The aortic input impedance of the MCS is also obtained and compared with the data from previous medical reports. At last a pediatric left ventricular assist device (LVAD) prototype is introduced for testing to further verify the effectiveness of the MCS. The experimental results indicate that this pediatric MCS is capable of reproducing basic hemodynamic characteristics of a child in both normal and pathological conditions and it is sufficient for testing a pediatric LVAD. Besides, most components constituting the main hydraulic part of this MCS are inexpensive off-the-shelf products, making the MCS easy and fast to build.

  19. Fabrication of single TiO2 nanotube devices with Pt interconnections using electron- and ion-beam-assisted deposition (United States)

    Lee, Mingun; Cha, Dongkyu; Huang, Jie; Ha, Min-Woo; Kim, Jiyoung


    Device fabrication using nanostructured materials, such as nanotubes, requires appropriate metal interconnections between nanotubes and electrical probing pads. Here, electron-beam-assisted deposition (EBAD) and ion-beam-assisted deposition (IBAD) techniques for fabrication of Pt interconnections for single TiO2 nanotube devices are investigated. IBAD conditions were optimized to reduce the leakage current as a result of Pt spreading. The resistivity of the IBAD-Pt was about three orders of magnitude less than that of the EBAD-Pt, due to low carbon concentration and Ga doping, as indicated by X-ray photoelectron spectroscopy analysis. The total resistances of single TiO2 nanotube devices with EBAD- or IBAD-Pt interconnections were 3.82 × 1010 and 4.76 × 108 Ω, respectively. When the resistivity of a single nanotube is low, the high series resistance of EBAD-Pt cannot be ignored. IBAD is a suitable method for nanotechnology applications, such as photocatalysis and biosensors.

  20. Totally implantable artificial hearts and left ventricular assist devices: selecting impermeable polycarbonate urethane to manufacture ventricles. (United States)

    Yang, M; Zhang, Z; Hahn, C; Laroche, G; King, M W; Guidoin, R


    In the development of a new generation of totally implantable artificial hearts and left ventricular assist devices (VADs) for long-term use, the selection of an acceptable material for the fabrication of the ventricles probably represents one of the greatest challenges. Segmented polyether urethanes used to be the material of choice due to their superior flexural performance, acceptable blood compatibility, and ease of processing. However, because they are known to degrade and to be readily permeable to water, they cannot meet the rigorous requirements needed for a new generation of implantable artificial hearts and VADs. Therefore, the objective of the present study was to identify alternative polymeric materials that would be satisfactory for fabricating the ventricles, and in particular, to determine the water permeability through membranes made from four commercial polycarbonate urethanes (Carbothane PC3570A, Chronoflex AR, Corethane 80A, and Corethane 55D) in comparison to those made from two traditional polyether urethanes (Tecoflex EG80A and Tecothane TT-1074A). In addition to determining the rate of water transmission through the six membranes by exposing them to deionized water, saline, and albumin-Krebs solution under pressure and measuring the displacement of liquid by means of a recently developed capillary method, the inherent surface and chemical properties of the six membranes were characterized by SEM, contact angle measurements, FTIR, DSC, and GPC techniques. The results of the study demonstrated that the rate of water transmission through the four polycarbonate urethane membranes was significantly lower than through the two polyether urethanes. In fact the lowest values were recorded with the two Corethane membranes, and the harder type 55D polymer had a lower value (2.7 x 10(-7) g/s cm2) than the softer 80A version (3.3 x 10(-7) g/s cm2). This level of water vapor permeability, which appears to be controlled primarily by a Fickian diffusion

  1. Percutaneous Ventricular Assist Devices: A Novel Approach in the Management of Patients With Acute Cardiogenic Shock. (United States)

    Ergle, Kevin; Parto, Parham; Krim, Selim R


    Despite recent advances in the management of heart failure, cardiogenic shock remains a challenging and devastating condition with significant morbidity and mortality. We review currently available percutaneous mechanical circulatory support (MCS) devices and address each device's characteristics, mechanism of action, specific clinical indications, and contraindications. Four types of percutaneous MCS devices are currently available: the intraaortic balloon pump (IABP), Impella devices, the TandemHeart, and extracorporal membrane oxygenation (ECMO). IABPs provide less hemodynamic support compared to the Impella, TandemHeart, and ECMO devices. However, because of its ease of placement and relatively small access catheter size, the IABP remains the most commonly used MCS device for the treatment of cardiogenic shock. When full cardiopulmonary support is needed, ECMO is the best option. Temporary MCS has emerged as a therapeutic option in the management of patients with acute cardiogenic shock. However, clinician familiarity with the indications, limitations, and benefits of individual MCS devices and enhanced patient comfort with the placement are paramount to improve patient outcomes.

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

    KAUST Repository

    In, Jung Bin


    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. 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


    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.

  4. Osteopathic treatment in a patient with left-ventricular assist device with left brachialgia: a case report (United States)

    Bordoni, Bruno; Marelli, Fabiola; Morabito, Bruno; Sacconi, Beatrice


    This study deals with an osteopathic approach used for a patient with left-ventricular assist device (L-VAD) affected by left brachialgia. Clinical examination revealed the presence of thoracic outlet syndrome and pectoralis minor syndrome, with compression of the left proximal ulnar nerve, related to the surgical sternotomy performed. The osteopathic techniques used can be classified as indirect and direct, addressed to the pectoralis minor and the first left rib, respectively. To our knowledge, this is the first text in literature with an osteopathic treatment in a patient with L-VAD. PMID:28144166

  5. Transcatheter aortic valve repair for management of aortic insufficiency in patients supported with left ventricular assist devices. (United States)

    Pal, Jay D; McCabe, James M; Dardas, Todd; Aldea, Gabriel S; Mokadam, Nahush A


    The development of new aortic insufficiency after a period of support with a left ventricular assist device can result in progressive heart failure symptoms. Transcatheter aortic valve repair can be an effective treatment in selected patients, but the lack of aortic valve calcification can result in unstable prostheses or paravalvular leak. We describe a technique of deploying a self-expanding CoreValve (Medtronic, Minneapolis, MN, USA) into the aortic annulus, followed by a balloon-expandable SAPIEN-3 (Edwards, Irvine, CA, USA).

  6. 3D Printing to Guide Ventricular Assist Device Placement in Adults With Congenital Heart Disease and Heart Failure. (United States)

    Farooqi, Kanwal M; Saeed, Omar; Zaidi, Ali; Sanz, Javier; Nielsen, James C; Hsu, Daphne T; Jorde, Ulrich P


    As the population of adults with congenital heart disease continues to grow, so does the number of these patients with heart failure. Ventricular assist devices are underutilized in adults with congenital heart disease due to their complex anatomic arrangements and physiology. Advanced imaging techniques that may increase the utilization of mechanical circulatory support in this population must be explored. Three-dimensional printing offers individualized structural models that would enable pre-surgical planning of cannula and device placement in adults with congenital cardiac disease and heart failure who are candidates for such therapies. We present a review of relevant cardiac anomalies, cases in which such models could be utilized, and some background on the cost and procedure associated with this process.

  7. 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:; 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)


    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.

  8. Joule-assisted silicidation for short-channel silicon nanowire devices. (United States)

    Mongillo, Massimo; Spathis, Panayotis; Katsaros, Georgios; Gentile, Pascal; Sanquer, Marc; De Franceschi, Silvano


    We report on a technique enabling electrical control of the contact silicidation process in silicon nanowire devices. Undoped silicon nanowires were contacted by pairs of nickel electrodes, and each contact was selectively silicided by means of the Joule effect. By a real-time monitoring of the nanowire electrical resistance during the contact silicidation process we were able to fabricate nickel-silicide/silicon/nickel-silicide devices with controlled silicon channel length down to 8 nm.

  9. Short and long term outcomes of 200 patients supported by continuous-flow left ventricular assist devices

    Institute of Scientific and Technical Information of China (English)

    Athanasios; Tsiouris; Gaetano; Paone; Hassan; W; Nemeh; Jamil; Borgi; Celeste; T; Williams; David; E; Lanfear; Jeffrey; A; Morgan


    AIM: To study the institutional experience over 8 years with 200 continuous-flow(CF)- left ventricular assist devices(LVAD).METHODS: We evaluated our institution’s LVAD database and analyzed all patients who received a CF LVAD as a bridge to transplant(BTT) or destination therapy from March 2006 until June 2014. We identified 200 patients, of which 179 were implanted with a Heart Mate II device(Thoratec Corp., Pleasanton, CA) and 21 received a Heartware HVAD(Heart Ware Inc., Framingham, MA).RESULTS: The mean age of our LVAD recipients was 59.3 years(range 17-81), 76%(152/200) were males, and 49% were implanted for the indication of BTT. The survival rate for our LVAD patients at 30 d, 6 mo, 12 mo, 2 years, 3 years, and 4 years was 94%, 86%, 78%, 71%, 62% and 45% respectively. The mean duration of LVAD support was 581 d(range 2-2595 d). Gastrointestinal bleeding(was the most common adverse event(43/200, 21%), followed by right ventricular failure(38/200, 19%), stroke(31/200, 15%), re exploration for bleeding(31/200, 15%),ventilator dependent respiratory failure(19/200, 9%) and pneumonia(15/200, 7%). Our driveline infection rate was 7%. Pump thrombosis occurred in 6% of patients. Device exchanged was needed in 6% of patients. On multivariate analysis, preoperative liver dysfunction, ventilator dependent respiratory failure, tracheostomy and right ventricular failure requiring right ventricular assist device support were significant predictors of post LVAD survival.CONCLUSION: Short and long term survival for patients on LVAD support are excellent, although outcomes still remain inferior compared to heart transplantation. The incidence of driveline infections, pump thrombosis and pump exchange have declined significantly in recent years.

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


    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.

  11. Autologous platelet concentrate and vacuum-assisted closure device use in a nonhealing total knee replacement. (United States)

    Klayman, Myra H; Trowbridge, Cody C; Stammers, Alfred H; Wolfgang, Gary L; Zijerdi, David A; Bitterly, Thomas J


    Following a total knee replacement surgery, a 51-year-old insulin-dependent patient presented with complications of impaired healing and postoperative trauma to the wound site. The inability of this leg wound to heal placed this patient at risk of amputation. Vacuum-assisted closure therapy was initiated at postoperative day 53; after 100 days of protracted wound history a series of treatments with topical platelet concentrates were added to the vacuum assisted closure therapy and conventional wound care therapy. The previous nonhealing wound presented with good granulation and margination that enabled a skin graft with good take on postoperative day 150.

  12. Meta-Analysis of Usefulness of Percutaneous Left Ventricular Assist Devices for High-Risk Percutaneous Coronary Interventions. (United States)

    Briasoulis, Alexandros; Telila, Tesfaye; Palla, Mohan; Mercado, Nestor; Kondur, Ashok; Grines, Cindy; Schreiber, Theodore


    High-risk percutaneous coronary intervention (PCI) is often offered to patients with extensive coronary artery disease, decreased left ventricular function, and co-morbid conditions that increase surgical risk. In these settings, percutaneous left ventricular assist devices (PVADs) can be used for hemodynamic support. To assess the effects of PVAD use on mortality, myocardial infarction, and complication rates in patients undergoing high-risk PCI, we systematically searched the electronic databases, MEDLINE, PUBMED, EMBASE, and Cochrane for prospective controlled trials and cohort studies of patients that received hemodynamic support with PVADs for high-risk PCI. The primary outcome measures were 30-day all-cause mortality, 30-day myocardial infarction rates, periprocedural major bleeding, and vascular complications. We included 12 studies with 1,346 participants who underwent Impella 2.5 L device placement and 8 cohort studies with 205 patients that received TandemHeart device for high-risk PCI. Short-term mortality rates were 3.5% and 8% and major bleeding rates were 7.1% and 3.6% with Impella and TandemHeart, respectively. Both devices are associated with comparable periprocedural outcomes in patients undergoing high-risk PCI. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Applying Taguchi methods for solvent-assisted PMMA bonding technique for static and dynamic micro-TAS devices. (United States)

    Hsu, Yi-Chu; Chen, Tang-Yuan


    This work examines numerous significant process parameters in the solvent-assistant Polymethyl methacrylate (PMMA) bonding scheme and presents two Micro-total-analysis System (micro-TAS) devices generated by adopting the optimal bonding parameters. The process parameters considered were heating temperature, applied loading, duration and solution. The effects of selected process parameters on bonding dimensions loss and strength, and subsequent optimal setting of the parameters were accomplished using Taguchi's scheme. Additionally, two micro-TAS devices were realized using a static paraffin microvalve and a dynamic diffuser micropump. The PMMA chips were carved using a CO2 laser that patterned device microchannels and microchambers. The operation principles, fabrication processes and experimental performance of the devices are discussed. This bonding technique has numerous benefits, including high bonding strength (240 kgf/cm2) and low dimension loss (2-6%). For comparison, this work also demonstrates that the normal stress of this technology is 2-15 times greater than that of other bonding technologies, including hot embossing, anodic bonding, direct bonding and thermal fusion bonding.

  14. Phonon-assisted and magnetic field induced Kondo tunneling in single molecular devices

    Energy Technology Data Exchange (ETDEWEB)

    Kikoin, K [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Kiselev, M N [The Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)


    We consider the Kondo tunneling induced by multiphonon emission/absorption processes in magnetic molecular complexes with low-energy singlet-triplet spin gap and show that the number of assisting phonons may be changed by varying the Zeeman splitting of excited triplet state. As a result, the structure of multiphonon Kondo resonances may be scanned by means of magnetic field tuning.

  15. Engineered embodiment: Comment on "The embodiment of assistive devices-from wheelchair to exoskeleton" by M. Pazzaglia and M. Molinari (United States)

    Kannape, Oliver Alan; Lenggenhager, Bigna


    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.

  16. The effect of an on-body personal lift assist device (PLAD) on fatigue during a repetitive lifting task. (United States)

    Lotz, Christy A; Agnew, Michael J; Godwin, Alison A; Stevenson, Joan M


    Occupations demanding frequent and heavy lifting are associated with an increased risk of injury. A personal lift assist device (PLAD) was designed to assist human muscles through the use of elastic elements. This study was designed to determine if the PLAD could reduce the level of general and local back muscle fatigue during a cyclical lifting task. Electromyography of two erector spinae sites (T9 and L3) was recorded during a 45-min lifting session at six lifts/lowers per minute in which male participants (n=10) lifted a box scaled to represent 20% of their maximum back extensor strength. The PLAD device reduced the severity of muscular fatigue at both muscle sites. RMS amplitude increased minimally (22% and 26%) compared to the no-PLAD condition (104% and 88%). Minimal median frequency decreases (0.33% and 0.41%) were observed in the PLAD condition compared to drops of 12% and 20% in the no-PLAD condition. The PLAD had an additional benefit of minimizing pre-post changes in muscular strength and endurance. The PLAD also resulted in a significantly lower rate of perceived exertion across the lifting session. It was concluded that the PLAD was effective at decreasing the level of back muscular fatigue.

  17. Model for end-stage liver disease predicts right ventricular failure in patients with left ventricular assist devices. (United States)

    Yost, Gardner L; Coyle, Laura; Bhat, Geetha; Tatooles, Antone J


    High rates of right ventricular failure continue to affect postoperative outcomes in patients implanted with left ventricular assist devices (LVADs). Development of right ventricular failure and implantation with right ventricular assist devices is known to be associated with significantly increased mortality. The model for end-stage liver disease (MELD) score is an effective means of evaluating liver dysfunction. We investigated the prognostic utility of postoperative MELD on post-LVAD implantation outcomes. MELD scores, demographic data, and outcomes including length of stay, survival, and postoperative right ventricular failure were collected for 256 patients implanted with continuous flow LVADs. Regression and Kaplan-Meier analyses were used to investigate the relationship between MELD and all outcomes. Increased MELD score was found to be an independent predictor of both right heart failure and necessity for RVAD implantation (OR 1.097, CI 1.040-1.158, p = 0.001; OR 1.121, CI 1.015, p = 0.024, respectively). Patients with RV failure and who underwent RVAD implantation had reduced postoperative survival compared to patients with RV dysfunction (no RV failure = 651.4 ± 609.8 days, RV failure = 392.6 ± 444.8 days, RVAD = 89.3 ± 72.8 days; p right heart failure and the necessity for RVAD implantation. Those patients with RV failure and RVADs experience significantly increased postoperative mortality compared to those without RV dysfunction.

  18. Combination of SVM and FERN for GPU-assisted texture recognition on mobile devices

    Directory of Open Access Journals (Sweden)

    Vsevolod Yugov


    Full Text Available Feature point matching and texture recognition are two of the most important problems in the image processing. Recently, several new approaches to these problems using simple local features and semi-naive Bayesian classification scheme have been developed. In our paper, we show how to enhance these techniques further by combining them with Support Vector Machines using online learning techniques. The resulting algorithm is simple, robust and can be adapted to various tasks in image processing. Furthermore, we demonstrate the advantages of our method by using it to achieve real-time texture recognition on a mobile device by utilizing parallel processing capabilities afforded by the device GPU.

  19. A Practical Hardware-Assisted Approach to Customize Trusted Boot for Mobile Devices

    DEFF Research Database (Denmark)

    Gonzalez, Javier; Hölzl, Michael; Riedl, Peter


    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...... their security requirements. This is a first step towards supporting usage control primitives for running applications. Our approach relies on off-the-shelf secure hardware that is available in a multitude of mobile devices: ARM TrustZone as a Trusted Execution Environment, and Secure Element as a tamper...

  20. Exercise blood pressure response during assisted circulatory support: comparison of the total artificial [corrected] heart with a left ventricular assist device during rehabilitation. (United States)

    Kohli, Harajeshwar S; Canada, Justin; Arena, Ross; Tang, Daniel G; Peberdy, Mary Ann; Harton, Suzanne; Flattery, Maureen; Doolin, Kelly; Katlaps, Gundars J; Hess, Michael L; Kasirajan, Vigneshwar; Shah, Keyur B


    The total artificial heart (TAH) consists of two implantable pneumatic pumps that replace the heart and operate at a fixed ejection rate and ejection pressure. We evaluated the blood pressure (BP) response to exercise and exercise performance in patients with a TAH compared to those with a with a continuous-flow left ventricular assist device (LVAD). We conducted a single-center, retrospective study of 37 patients who received a TAH and 12 patients implanted with an LVAD. We measured the BP response during exercise, exercise duration and change in tolerated exercise workload over an 8-week period. In patients with a TAH, baseline BP was 120/69 ± 13/13, exercise BP was 118/72 ± 15/10 and post-exercise BP was 120/72 ± 14/12. Mean arterial BP did not change with exercise in patients with a TAH (88 ± 10 vs 88 ± 11; p = 0.8), but increased in those with an LVAD (87 ± 8 vs 95 ± 13; p exercise, the association was not statistically significant (β = -0.1, p = 0.4). MAP correlated positively with METs achieved in patients with LVADs (MAP: β = 0.26, p = 0.04). Despite the abnormal response to exercise, patients with a TAH participated in physical therapy (median: 5 days; interquartile range [IQR] 4 to 7 days) and treadmill exercise (19 days; IQR: 13 to 35 days) early after device implantation, with increased exercise intensity and duration over time. During circulatory support with a TAH, the BP response to exercise was blunted. However, aerobic exercise training early after device implantation was found to be safe and feasible in a supervised setting. 2011 International Society for Heart and Lung Transplantation. All rights reserved.

  1. A numerical method to enhance the performance of a cam-type electric motor-driven left ventricular assist device. (United States)

    Huang, Huan; Yang, Ming; Lu, Cunyue; Xu, Liang; Zhuang, Xiaoqi; Meng, Fan


    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.

  2. CFD Design and Analysis of a Passively Suspended Tesla Pump Left Ventricular Assist Device (United States)

    Medvitz, Richard B.; Boger, David A.; Izraelev, Valentin; Rosenberg, Gerson; Paterson, Eric G.


    This paper summarizes the use of computational fluid dynamics (CFD) to design a novelly suspended Tesla LVAD. Several design variants were analyzed to study the parameters affecting device performance. CFD was performed at pump speeds of 6500, 6750 and 7000 RPM and at flow rates varying from 3 to 7 liter-per-minute (LPM). The CFD showed that shortening the plates nearest the pump inlet reduced the separations formed beneath the upper plate leading edges and provided a more uniform flow distribution through the rotor gaps, both of which positively affected the device hydrodynamic performance. The final pump design was found to produce a head rise of 77 mmHg with a hydraulic efficiency of 16% at the design conditions of 6 LPM throughflow and a 6750 RPM rotation rate. To assess the device hemodynamics the strain rate fields were evaluated. The wall shear stresses demonstrated that the pump wall shear stresses were likely adequate to inhibit thrombus deposition. Finally, an integrated field hemolysis model was applied to the CFD results to assess the effects of design variation and operating conditions on the device hemolytic performance. PMID:21595722

  3. Preliminary experience with the MicroMed DeBakey pediatric ventricular assist device. (United States)

    Fraser, Charles D; Carberry, Kathleen E; Owens, W Richard; Arrington, Karol A; Morales, David L S; Heinle, Jeffery S; McKenzie, E Dean


    Mechanical circulatory support for both acute and chronic heart failure is a widely applied therapeutic option in the adult population with a variety of devices clinically available. Technology in this field has advanced sufficiently such that long-term support or "destination therapy" has become a generally accepted reality. Similar progress has not occurred in the field of device support for heart failure in children. While the number of potential patients is significantly lower in the pediatric population, the clinical relevance and poignancy of individual need are nonetheless real. Until recently, children with heart failure have been largely disadvantaged in comparison to their adult counterparts. The DeBakey VAD Child (MicroMed Technology, Inc, Houston, TX) represents a hopeful initial step in the direction of reducing the technological gap between adults and children. While the clinical experience with this device is limited at present, preliminary results are encouraging. This report will provide an overview of the DeBakey VAD Child, including device specifications, indications for clinical use, surgical and postoperative considerations, and updated clinical experience.

  4. Design and Implementation of NTU Wearable Exoskeleton as an Enhancement and Assistive Device


    Low, K. H.; Liu, X; Yu, H.


    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. Design and Implementation of NTU Wearable Exoskeleton as an Enhancement and Assistive Device


    Low, K. H.; Liu, X; Yu, H.


    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...

  6. Dispositivos de tecnología de asistencia para alimentación = Devices of assistive technology for feeding

    Directory of Open Access Journals (Sweden)

    Losada Gómez, A


    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

  7. Longitudinal structural, functional, and cellular myocardial alterations with chronic centrifugal continuous-flow left ventricular assist device support. (United States)

    Muthiah, Kavitha; Humphreys, David T; Robson, Desiree; Dhital, Kumud; Spratt, Phillip; Jansz, Paul; Macdonald, Peter S; Hayward, Christopher S


    Left ventricular assist device (LVAD) support triggers adaptations within failing hearts. The HeartWare (HeartWare International, Inc., Framingham, MA) LVAD exhibits different flow profiles and afterload dependence compared with previous-generation devices, which may alter remodelling patterns. We sought to characterize myocardial adaptation to third-generation centrifugal-flow LVADs at a functional, hemodynamic, and structural level in addition to profiling transcriptomal changes using next-generation sequencing platforms. We studied 37 patients supported with the HeartWare device with paired measurements of invasive hemodynamics, serial longitudinal left ventricular (LV) and right ventricular (RV) 3-dimensional echocardiography, and N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) measurements. Paired samples for comparison of histologic myocardial cellular size and transcriptomal profiling were performed on specimens taken at pump implant and transplantation. The mean support duration was 280 ± 163 days. Mechanical unloading after HeartWare support resulted in reduced filling pressures (mean pulmonary capillary wedge pressure 27.1 ± 6.6 to 14.8 ± 5.1 mm Hg, p hypertrophy, and an improvement in LV and RV ejection fractions. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  8. Functional hearing in the classroom: assistive listening devices for students with hearing impairment in a mainstream school setting. (United States)

    Zanin, Julien; Rance, Gary


    To assess the benefit of assistive listening devices (ALDs) for students with hearing impairment in mainstream schools. Speech recognition (CNC words) in background noise was assessed in a typical classroom. Participants underwent testing using four device configurations: (1) HA(s)/CI(s) alone, (2) soundfield amplification, (3) remote microphone (Roger Pen) on desk and (4) remote microphone at the loudspeaker. A sub-group of students subsequently underwent a 2-week classroom trial of each ALD. Degree of improvement from baseline [HA(s)/CI(s)] alone was assessed using teacher and student Listening Inventory for Education-Revised (LIFE-R) questionnaires. In all, 20 students, aged 12.5-18.9 years, underwent speech recognition assessment. In total, 10 of these participated in the classroom trial. Hearing loss ranged from mild-to-profound levels. Performance in each ALD configuration was higher than for HAs/CIs alone (p  0.05). Speech recognition improvements were demonstrated with the implementation of both remote microphones and soundfield systems. Both students and teachers reported functional hearing advantages in the classroom when using the remote microphone in concert with their standard hearing devices.

  9. False positive hepatitis C antibody test results in left ventricular assist device recipients: increased risk with age and transfusions (United States)

    Lee, Doreen; Colovai, Adriana; Levy, Dana; Vasovic, Ljiljana; Roach, Keith W.; Shuter, Jonathan; Goldstein, Daniel; D’Alessandro, David; Jorde, Ulrich P.; Muggia, Victoria A.


    Left ventricular assist devices (LVADs) have been successfully used in patients with heart failure. However, LVADs may trigger immune activation, leading to higher frequencies of autoantibodies. We describe the clinical, epidemiological, and laboratory characteristics of LVAD recipients with false positive hepatitis C (FPHC) serology among 39 consecutive adult LVAD recipients who bridged to heart transplantation from January 2007 to January 2013 at Montefiore Medical Center. FPHC patients were identified as those with post-LVAD positive hepatitis C ELISA antibody tests and negative confirmatory testing with hepatitis C RNA PCR and/or radioimmunoblot assay. Ten (26%) patients previously seronegative for hepatitis C were found to have FPHC after device placement. Of the 39 patients, 32 had HeartMate II devices. The mean age at LVAD placement was 55 years. FPHC correlated with older age at the time of LVAD implantation and with receipt of packed red blood cell transfusions, but not with gender, fresh frozen plasma transfusions, panel reactive antibodies, globulin fraction, rheumatoid factor, or anticardiolipin antibodies. Clinicians should be aware of this increased risk of FPHC in older LVAD patients and those more heavily transfused in order to avoid unnecessary apprehension and possible delay in transplantation. Further studies should be done to evaluate the possible relationship between transfused blood products and immunomodulation. PMID:28203425

  10. Implementation study of an analog spiking neural network for assisting cardiac delay prediction in a cardiac resynchronization therapy device. (United States)

    Sun, Qing; Schwartz, François; Michel, Jacques; Herve, Yannick; Dalmolin, Renzo


    In this paper, we aim at developing an analog spiking neural network (SNN) for reinforcing the performance of conventional cardiac resynchronization therapy (CRT) devices (also called biventricular pacemakers). Targeting an alternative analog solution in 0.13- μm CMOS technology, this paper proposes an approach to improve cardiac delay predictions in every cardiac period in order to assist the CRT device to provide real-time optimal heartbeats. The primary analog SNN architecture is proposed and its implementation is studied to fulfill the requirement of very low energy consumption. By using the Hebbian learning and reinforcement learning algorithms, the intended adaptive CRT device works with different functional modes. The simulations of both learning algorithms have been carried out, and they were shown to demonstrate the global functionalities. To improve the realism of the system, we introduce various heart behavior models (with constant/variable heart rates) that allow pathologic simulations with/without noise on the signals of the input sensors. The simulations of the global system (pacemaker models coupled with heart models) have been investigated and used to validate the analog spiking neural network implementation.

  11. First World Report of Internal Power Cable Repair in Left Ventricular Assist Device Jarvik 2000: Case Report. (United States)

    Sassi, C G; Cameli, M; Dokollari, A; Diciolla, F; Scolletta, S; Ricci, C; Lucatelli, P; Mondillo, S; Maccherini, M


    There are limited clinical reports concerning internal power cable fixing in left ventricular assist device (L-VAD) patients. Actually there are no reports in the literature about Jarvik 2000 internal cable repair. We show the first description of a technique for surgical reparation of such a fatal complication. The patient was a 62-year-old woman who had L-VAD implantation (Jarvik 2000) with outflow graft apposition in descending thoracic aorta through left thoracotomy access, in 2009. She arrived urgently on January 25, 2014 for Jarvik 2000 dysfunction correlated with head movements. The neck X-rays revealed the rupture of one of the nine power cables located inside the neck and the damaging of two more cables nearby to be ruptured. On the same day she got pump failure due to the final interruption of the remaining two cables, we were obliged to install femoro-femoral extracorporeal membrane oxygenation (ECMO) assistance, to repair the power cables, approaching them through a pacemaker extension cable. The L-VAD outflow was occluded with vascular ball occluder inserted via right axillary artery under fluoroscopy before ECMO installation. At the end the ECMO assistance was interrupted and the Jarvik 2000 was turned back on. The patient was dismissed from the hospital 12 days after the procedure. At the moment the international literature is poor regarding this issue. This case provides evidence that in emergency conditions ECMO assistance is mandatory and a hybrid surgical and radiological approach could help to repair the damage in safe conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. The effect of on-body lift assistive device on the lumbar 3D dynamic moments and EMG during asymmetric freestyle lifting. (United States)

    Abdoli-E, Mohammad; Stevenson, Joan M


    A new on-body personal lift assistive device was developed to reduce force requirements of back muscles during lifting and static holding tasks. Nine male subjects participated in the study. Twelve Fastrak sensors were used to record positions and rotations of the segments. Trunk muscles were normalized to maximum and integrated electromyographic amplitudes of the left and right thoracic erector spinae, lumbar erector spinae, external obliques, and rectus abdominalis were compared in asymmetrical lifting for three different loads (5 kg, 15 kg, 25 kg) using free style under two conditions: with and without a lift assistive device. The assistive device significantly reduced the required muscular effort of the lumbar and thoracic erector spinae (P=0.001) with no significant differences in the level of abdominal muscular activity. Average integrated electromyography amplitudes were reduced across all subjects by 23.9% for lumbar erector spinae, 24.4% for thoracic erector spinae, and 34.9% for the contralateral external oblique muscles. The assistive device had its greatest impact on smaller moments with 30% reduction in lateral bending, and 24% reduction in rotational moments, with only 19.5% a reduction in larger flexion-extension moments. To investigate whether the lift assistive device affected lifting kinematics, the device tensions were zeroed mathematically. No kinematic differences in lifting technique would explain this magnitude of moment reduction. The on-body assistive device reduced the required muscular effort of the lumbar and thoracic erector spinae without adversely affecting the level of abdominal muscle activity. These reductions were mirrored by similar 3D moment reductions.

  13. Au Nanocluster assisted PCE improvement in PEDOT: PSS - Si Hybrid Devices (United States)

    Sharma, Manisha; Pudasaini, Pushpa Raj; Ayon, Arturo A.


    Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), a P-type organic polymer is frequently employed in the fabrication of heterojunction p-n solar cell devices due to its proper HOMO-LUMO band gap as well as its tunable conductivity. In this report we describe the incorporation of gold (Au) nanoclusters in the PEDOT:PSS blend and its influence on the power-conversion-efficiency (PCE) on planar silicon (Si) hybrid heterojunction solar cell devices. Specifically, the reference samples without the aforementioned nanoclusters, were measured to exhibit a 6.10% PCE, value that increased to 7.55% upon the addition of the Au nanoclusters. The observed increase in the PCE is attributed to the enhanced electrical conductivity of the PEDOT:PSS films due to the incorporation of the nanoclusters, which is directly reflected in their improved fill factor. It is further theorized that the presence of Au nanoclusters in the insulating PSS layer in the PEDOT:PSS blend have a positive influence in the charge collection effectiveness of the devices produced. Considering that the Au nanoparticles involved in this research exercise had an average size of only 4 nm, it is considered that plasmonic effects did not play a relevant role in the observed PCE improvement.

  14. Metal assisted catalyzed etched (MACE) black Si: optics and device physics. (United States)

    Toor, Fatima; Miller, Jeffrey B; Davidson, Lauren M; Duan, Wenqi; Jura, Michael P; Yim, Joanne; Forziati, Joanne; Black, Marcie R


    Metal-assisted catalyzed etching (MACE) of silicon (Si) is a controllable, room-temperature wet-chemical technique that uses a thin layer of metal to etch the surface of Si, leaving behind various nano- and micro-scale surface features, including nanowires (NWs), that can be tuned to achieve various useful engineering goals, in particular with respect to Si solar cells. In this review, we introduce the science and technology of MACE from the literature, and provide an in-depth analysis of MACE to enhance Si solar cells, including the outlook for commercial applications of this technology.

  15. Does the personal lift-assist device affect the local dynamic stability of the spine during lifting? (United States)

    Graham, Ryan B; Sadler, Erin M; Stevenson, Joan M


    The personal lift-assist device (PLAD) is an on-body ergonomic aid that reduces low back physical demands through the restorative moment of an external spring element, which possesses a mechanical advantage over the erector spinae. Although the PLAD has proven effective at reducing low back muscular demand, spinal moments, and localized muscular fatigue during laboratory and industrial tasks, the effects of the device on the neuromuscular control of spinal stability during lifting have yet to be assessed. Thirty healthy subjects (15M, 15F) performed repetitive lifting for three minutes, at a rate of 10 lifts per minute, with and without the PLAD. Maximum finite-time Lyapunov exponents, representing short-term (λ(max-s)) and long-term (λ(max-l)) divergence were calculated from the measured trunk kinematics to estimate the local dynamic stability of the lumbar spine. Using a mixed-design repeated-measures ANOVA, it was determined that wearing the PLAD did not significantly change λ(max-s) (μ(NP)=0.335, μ(P)=0.321, p=0.225), but did significantly reduce λ(max-l) (μ(NP)=0.0024, μ(P)=-0.0011, p=0.014, η(2)=0.197). There were no between-subject effects of sex, or significant interactions (p>0.720). The present results indicated that λ(max-s) was not statistically different between the device conditions, but that the PLAD significantly reduced λ(max-l) to a negative (stable) value. This shows that subjects' neuromuscular systems were able to respond to local perturbations more effectively when wearing the device, reflecting a more stable control of spinal movements. These findings are important when recommending the PLAD for long-term industrial or clinical use. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. A fluid dynamics study in a 50 cc pulsatile ventricular assist device: influence of heart rate variability. (United States)

    Nanna, Jason C; Navitsky, Michael A; Topper, Stephen R; Deutsch, Steven; Manning, Keefe B


    Although left ventricular assist devices (LVADs) have had success in supporting severe heart failure patients, thrombus formation within these devices still limits their long term use. Research has shown that thrombosis in the Penn State pulsatile LVAD, on a polyurethane blood sac, is largely a function of the underlying fluid mechanics and may be correlated to wall shear rates below 500 s(-1). Given the large range of heart rate and systolic durations employed, in vivo it is useful to study the fluid mechanics of pulsatile LVADs under these conditions. Particle image velocimetry (PIV) was used to capture planar flow in the pump body of a Penn State 50 cubic centimeters (cc) LVAD for heart rates of 75-150 bpm and respective systolic durations of 38-50%. Shear rates were calculated along the lower device wall with attention given to the uncertainty of the shear rate measurement as a function of pixel magnification. Spatial and temporal shear rate changes associated with data collection frequency were also investigated. The accuracy of the shear rate calculation improved by approximately 40% as the resolution increased from 35 to 12 μm/pixel. In addition, data collection in 10 ms, rather than 50 ms, intervals was found to be preferable. Increasing heart rate and systolic duration showed little change in wall shear rate patterns, with wall shear rate magnitude scaling by approximately the kinematic viscosity divided by the square of the average inlet velocity, which is essentially half the friction coefficient. Changes in in vivo operating conditions strongly influence wall shear rates within our device, and likely play a significant role in thrombus deposition. Refinement of PIV techniques at higher magnifications can be useful in moving towards better prediction of thrombosis in LVADs.

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

    DEFF Research Database (Denmark)

    Moiseyenko, Rayisa; Bruus, Henrik


    The ability to precisely sort individual microparticles/cells/droplets in suspension is important for various chemical and biological applications such as cancer cell detection, drug screening etc. The past decade, label- free particle handling of particle suspensions by ultrasonic radiation forces...... 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...

  18. Numerical And Experimental Analysis Of Fracture Of Athrombogenic Coatings Deposited On Ventricular Assist Device In Micro-Shear Test

    Directory of Open Access Journals (Sweden)

    Kopernik M.


    Full Text Available The Polish left ventricular assist device (LVAD – RELIGA_EXT will be made of thermoplastic polycarbonate-urethane (Bionate II with deposited athrombogenic nano-coatings: gold (Au and titanium nitride (TiN. Referring to the physical model, the two-scale model of LVAD developed in the previous works in the authors’ finite element code is composed of a macro-model of blood chamber and a micro-model of wall: TiN, Au and Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture based on localization of zones of the biggest values of triaxiality factor. The introduction of Au interlayer between TiN and polymer improved the toughness of the connection, and increased the compressive residual stress in the coating what resulted in reduction of stress and strain close to the boundary between substrate and coating.

  19. The Enhanced Light Absorptance and Device Application of Nanostructured Black Silicon Fabricated by Metal-assisted Chemical Etching (United States)

    Zhong, Hao; Guo, Anran; Guo, Guohui; Li, Wei; Jiang, Yadong


    We use metal-assisted chemical etching (MCE) method to fabricate nanostructured black silicon on the surface of C-Si. The Si-PIN photoelectronic detector based on this type of black silicon shows excellent device performance with a responsivity of 0.57 A/W at 1060 nm. Silicon nanocone arrays can be created using MCE treatment. These modified surfaces show higher light absorptance in the near-infrared range (800 to 2500 nm) compared to that of C-Si with polished surfaces, and the variations in the absorption spectra of the nanostructured black silicon with different etching processes are obtained. The maximum light absorptance increases significantly up to 95 % in the wavelength range of 400 to 2500 nm. Our recent novel results clearly indicate that nanostructured black silicon made by MCE has potential application in near-infrared photoelectronic detectors.

  20. Reversible Motor Paralysis and Early Cardiac Rehabilitation in Patients With Advanced Heart Failure Receiving Left Ventricular Assist Device Therapy. (United States)

    Amao, Rie; Imamura, Teruhiko; Nakahara, Yasuo; Noguchi, Satoko; Kinoshita, Osamu; Yamauchi, Haruo; Ono, Minoru; Haga, Nobuhiko


    Advanced heart failure (HF) is sometimes complicated with brain impairment because of a microthrombosis caused by decreased left ventricular contraction or reduced brain circulation. Some patients may recover after left ventricular assist device (LVAD) implantation. However, little is known about the perioperative therapeutic strategy in patients suffering from such complications, particularly from a cardiac rehabilitation viewpoint. We report on a 58-year-old male patient with a previous history of poliomyelitis and a light paralysis in the left upper extremity, who suffered left hemiplegia with no evidence of stroke after hemodynamic deterioration. The combination therapy of perioperative cardiac rehabilitation and LVAD therapy improved his left hemiplegia as well as activities of daily living, and the patient was discharged on foot on postoperative day 72 after briefing the family on LVAD home management. Early initiation of cardiac rehabilitation before LVAD implantation may be a key for the smooth discharge and resocialization of patients suffering from brain impairment complicated with advanced HF.

  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;


    LVAD implantation. METHODS: Health status [Kansas City Cardiomyopathy Questionnaire (KCCQ); Short-Form 12 (SF-12)] were assessed at 3-4 weeks after implantation, and at 3, 6 and 12 months follow up in 54 LVAD patients (74% men; mean age 54 ± 9 years). RESULTS: Patients experienced significant......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...... improvements in health status between baseline and 3 months follow-up as assessed by the KCCQ (clinical summary score: F = 33.49, P 12 (physical component score: F = 31.59, P 

  2. [Fondaparinux as an alternative anticoagulant in heparin-induced thrombocytopenia in the patient with a ventricular assist device]. (United States)

    Cegarra-Sanmartín, V; Paniagua, P; Galán, J; Muñoz, C; Moral, M V


    Heparin-induced thrombocytopenia is a reaction associated with the use of this drug. It occurs in up to 3% of patients treated for at least 5 days. Its treatment is to stop the heparin, and according to patient needs, replace it with another anticoagulant. We present a patient who, after a heart transplant, and the need for a ventricular assist device, required anticoagulation. The patient developed heparin-induced thrombocytopenia. Heparin was stopped and anticoagulation was replaced by fondaparinux. The peri-operative complications and the management of the coagulation are described. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  3. Use of a home vacuum-assisted closure device in the burn population is both cost-effective and efficacious. (United States)

    Mushin, Oren P; Bogue, Jarrod T; Esquenazi, Mica D; Toscano, Nicole; Bell, Derek E


    The vacuum assisted closure device (VAC) improves wound-healing when utilized as a bolster to secure split thickness skin grafts (STSG). Patients typically remain hospitalized for VAC therapy; however, home VACs (hVAC) are now available. Limited studies examine burns treated with hVAC as a STSG bolster. A retrospective study of records from an ABA verified regional burn center was conducted over 23 months. Patients included STSGs for burn. Data points included demographics, burn mechanism and location, graft characteristics, hospital length of stay (LOS), and time to heal. Fifty patients were included, with average age of 39 years (range hVAC over the same period. The hVAC is a cost-effective STSG bolster in the burn population for appropriate candidates. Excellent graft-take and low morbidity rates imply that this is an efficacious alternative for STSG bolster. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  4. The use of percutaneous left ventricular assist device in high-risk percutaneous coronary intervention and cardiogenic shock. (United States)

    Akhondi, Andre Babak; Lee, Michael S


    Patients with high-risk coronary lesions may be denied coronary artery bypass grafting due to excessive comorbidities. Percutaneous coronary intervention (PCI) may be a feasible revascularization strategy in high-risk patients who present with ST-elevation myocardial infarction and cardiogenic shock. Historically, the use if intra-aortic balloon pump (IABP) has been used in high-risk PCI and cardiogenic shock. However, recent data has shown that elective IABP insertion did not reduce the incidence of major cardiovascular events following PCI. The use of a left ventricular assist device is a reasonable and safe alternative compared with IABP counterpulsation, giving greater cardiac output and hemodynamic support in patients undergoing high-risk PCI and in those with severe cardiogenic shock. This review outlines a case of severe cardiogenic shock and hemodynamic instability where high-risk PCI is a reasonable option.

  5. Self-dissolution assisted coating on magnesium metal for biodegradable bone fixation devices (United States)

    Khakbaz, Hadis; Walter, Rhys; Gordon, Timothy; Bobby Kannan, M.


    An attempt was made to develop a self-dissolution assisted coating on a pure magnesium metal for potential bone fixation implants. Magnesium phosphate cement (MPC) was coated successfully on the magnesium metal in ammonium dihydrogen phosphate solution. The in vitro degradation behaviour of the MPC coated metal was evaluated using electrochemical techniques. The MPC coating increased the polarisation resistance (RP) of the metal by ˜150% after 2 h immersion in simulated body fluid (SBF) and reduced the corrosion current density (icorr) by ˜80%. The RP of the MPC coated metal remained relatively high even after 8 h immersion period. However, post-degradation analysis of the MPC coated metal revealed localized attack. Hence, the study suggests that MPC coating alone may not be beneficial, but this novel coating could provide additional protection if used as a precursor for other potential coatings such as biodegradable polymers or calcium phosphates.

  6. Wearable Monitoring Devices for Assistive Technology: Case Studies in Post-Polio Syndrome

    Directory of Open Access Journals (Sweden)

    Giuseppe Andreoni


    Full Text Available The correct choice and customization of an orthosis are crucial to obtain the best comfort and efficiency. This study explored the feasibility of a multivariate quantitative assessment of the functional efficiency of lower limb orthosis through a novel wearable system. Gait basographic parameters and energetic indexes were analysed during a Six-Minute Walking Test (6-MWT through a cost-effective, non-invasive polygraph device, with a multichannel wireless transmission, that carried out electro-cardiograph (ECG; impedance-cardiograph (ICG; and lower-limb accelerations detection. Four subjects affected by Post-Polio Syndrome (PPS were recruited. The wearable device and the semi-automatic post-processing software provided a novel set of objective data to assess the overall efficiency of the patient-orthosis system. Despite the small number of examined subjects, the results obtained with this new approach encourage the application of the method thus enlarging the dataset to validate this promising protocol and measuring system in supporting clinical decisions and out of a laboratory environment.

  7. Family of graphene-assisted resonant surface optical excitations for terahertz devices (United States)

    Lin, I-Tan; Liu, Jia-Ming; Tsai, Hsin-Cheng; Wu, Kaung-Hsiung; Syu, Jheng-Yuan; Su, Ching-Yuan


    The majority of the proposed graphene-based THz devices consist of a metamaterial that can optically interact with graphene. This coupled graphene-metamaterial system gives rise to a family of resonant modes such as the surface plasmon polariton (SPP) modes of graphene, the geometrically induced SPPs, also known as the spoof SPP modes, and the Fabry-Perot (FP) modes. In the literature, these modes are usually considered separately as if each could only exist in one structure. By contrast, in this paper, we show that even in a simple metamaterial structure such as a one-dimensional (1D) metallic slit grating, these modes all exist and can potentially interact with each other. A graphene SPP-based THz device is also fabricated and measured. Despite the high scattering rate, the effective SPP resonances can still be observed and show a consistent trend between the effective frequency and the grating period, as predicted by the theory. We also find that the excitation of the graphene SPP mode is most efficient in the terahertz spectral region due to the Drude conductivity of graphene in this spectral region. PMID:27739504

  8. Indications for long-term assist device placement as bridge to transplantation. (United States)

    Sun, Benjamin C


    The current indications for long-term mechanical support as bridge to transplantation first require the patient to be a transplant candidate. Often times a patient presents with limited history and refractory cardiogenic shock, where a full transplant work-up for contraindications cannot be safely performed. The use of short-term mechanical support can be used to help filter out many patients who have easily identifiable contraindications to heart transplant. Nevertheless, patients need to be listed for a heart transplant before the implantation of some of these devices. This paradigm needs to be altered, because there are many instances where mechanical support can be used to support a patient for an intervention to "make" them a transplant candidate where they otherwise would not have been. Long-term mechanical support can overcome the cardiac contraindication to the surgical/interventional therapy to "cure" them of the process that would have prevented them from being a good cardiac transplant candidate in the first place. Noncardiac surgical procedures are well tolerated in these patients [11]. The FDA is currently evaluating the Vented Electric Heartmate system for use as destination therapy for patients who are not transplant candidates. Approval for this indication (with a device that is already approved for bridge to transplantation) will allow this paradigm shift. This system could be used in the group who may be good candidates, but not determined. If they were subsequently determined to not be a good surgical candidate, they would be chronically supported with the LVAD as destination therapy.

  9. Development of a syringe pump assisted dynamic headspace sampling technique for needle trap device. (United States)

    Eom, In-Yong; Niri, Vadoud H; Pawliszyn, Janusz


    This paper describes a new approach that combines needle trap devices (NTDs) with a dynamic headspace sampling technique (purge and trap) using a bidirectional syringe pump. The needle trap device is a 22-G stainless steel needle 3.5-in. long packed with divinylbenzene sorbent particles. The same sized needle, without packing, was used for purging purposes. We chose an aqueous mixture of benzene, toluene, ethylbenzene, and p-xylene (BTEX) and developed a sequential purge and trap (SPNT) method, in which sampling (trapping) and purging cycles were performed sequentially by the use of syringe pump with different distribution channels. In this technique, a certain volume (1 mL) of headspace was sequentially sampled using the needle trap; afterwards, the same volume of air was purged into the solution at a high flow rate. The proposed technique showed an effective extraction compared to the continuous purge and trap technique, with a minimal dilution effect. Method evaluation was also performed by obtaining the calibration graphs for aqueous BTEX solutions in the concentration range of 1-250 ng/mL. The developed technique was compared to the headspace solid-phase microextraction method for the analysis of aqueous BTEX samples. Detection limits as low as 1 ng/mL were obtained for BTEX by NTD-SPNT.

  10. Inhaled nitric oxide plus iloprost in the setting of post-left assist device right heart dysfunction. (United States)

    Antoniou, Theofani; Prokakis, Christos; Athanasopoulos, Georgios; Thanopoulos, Apostolos; Rellia, Panagiota; Zarkalis, Dimitrios; Kogerakis, Nektarios; Koletsis, Efstratios N; Bairaktaris, Andreas


    Pulmonary hypertension and right ventricular (RV) dysfunction may complicate the implantation of a left ventricular assist device (LVAD). We examined whether inhaled vasodilators can sufficiently reduce RV afterload, avoiding the need for temporary RV mechanical support. The study includes 7 patients with RV dysfunction after LVAD insertion. Treatment consisted of inotropes, inhaled nitric oxide (10 ppm), and iloprost (10 μg) in repeated doses. Full hemodynamic profile was obtained before inhalation, during administration of inhaled NO alone (before and after iloprost), as well as after the first two doses of inhaled iloprost. Tricuspid annular velocity was estimated at baseline and before and after adding iloprost. There was a statistically significant reduction in pulmonary vascular resistance (PVR), mean pulmonary artery pressure (MPAP), RV systolic pressure, and pulmonary capillary wedge pressure, and a considerable increase in LVAD flow, LV flow rate index, and tricuspid annular velocity at all points of evaluation versus baseline. By the end of the protocol, MPAP/mean systemic arterial pressure, and PVR/systemic vascular resistance ratios were reduced by 0.17±0.03 (95% confidence interval, 0.10 to 0.25, p=0.001) and 0.12±0.025 (95% confidence interval, 0.06 to 0.18; p=0.003), respectively. The tricuspid annular velocity increased by 2.3±0.18 cm/s (95% confidence interval, 1.83 to 2.73 cm/s; piloprost showed an important decrease in PVR (p=0.022), MPAP (p=0.001), pulmonary capillary wedge pressure (p=0.002), and RV systolic pressure (piloprost sufficiently decreased PVR and MPAP on the basis of an additive effect, improved RV function, and avoided the need for RV assist device. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Risk Stratification of Patients With Current Generation Continuous-Flow Left Ventricular Assist Devices Being Bridged to Heart Transplantation. (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; 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 < 0.001), and ambulatory cohort (6.4, 11.5, 17.2; p < 0.001). We derived a left ventricular 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.

  12. The Effectiveness and Safety of Exoskeletons as Assistive and Rehabilitation Devices in the Treatment of Neurologic Gait Disorders in Patients with Spinal Cord Injury: A Systematic Review. (United States)

    Fisahn, Christian; Aach, Mirko; Jansen, Oliver; Moisi, Marc; Mayadev, Angeli; Pagarigan, Krystle T; Dettori, Joseph R; Schildhauer, Thomas A


    Study Design Systematic review. Clinical Questions (1) When used as an assistive device, do wearable exoskeletons improve lower extremity function or gait compared with knee-ankle-foot orthoses (KAFOs) in patients with complete or incomplete spinal cord injury? (2) When used as a rehabilitation device, do wearable exoskeletons improve lower extremity function or gait compared with other rehabilitation strategies in patients with complete or incomplete spinal cord injury? (3) When used as an assistive or rehabilitation device, are wearable exoskeletons safe compared with KAFO for assistance or other rehabilitation strategies for rehabilitation in patients with complete or incomplete spinal cord injury? Methods PubMed, Cochrane, and Embase databases and reference lists of key articles were searched from database inception to May 2, 2016, to identify studies evaluating the effectiveness of wearable exoskeletons used as assistive or rehabilitative devices in patients with incomplete or complete spinal cord injury. Results No comparison studies were found evaluating exoskeletons as an assistive device. Nine comparison studies (11 publications) evaluated the use of exoskeletons as a rehabilitative device. The 10-meter walk test velocity and Spinal Cord Independence Measure scores showed no difference in change from baseline among patients undergoing exoskeleton training compared with various comparator therapies. The remaining primary outcome measures of 6-minute walk test distance and Walking Index for Spinal Cord Injury I and II and Functional Independence Measure-Locomotor scores showed mixed results, with some studies indicating no difference in change from baseline between exoskeleton training and comparator therapies, some indicating benefit of exoskeleton over comparator therapies, and some indicating benefit of comparator therapies over exoskeleton. Conclusion There is no data to compare locomotion assistance with exoskeleton versus conventional KAFOs

  13. Use of the Impella 2.5 left ventricular assist device in a patient with cardiogenic shock secondary to takotsubo cardiomyopathy. (United States)

    Rashed, Ahmed; Won, Sekon; Saad, Marwan; Schreiber, Theodore


    We report a case of cardiogenic shock, believed to be secondary to stress-induced cardiomyopathy, managed by an Impella 2.5 assist device. Apical ballooning pattern was evident on left ventriculogram with no significant coronary artery disease on coronary angiography. Cardiogenic shock was initially managed medically with inotropes and vasopressors, but because the patient was clinically deteriorating, an Impella 2.5 left ventricular assist device was implanted. Remarkable recovery occurred within 48 h of implantation with significant increase in ejection fraction and only minimal residual apical hypokinesis observed on repeat ventriculogram.

  14. 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. (United States)

    Prange-Lasonder, Gerdienke B; Radder, Bob; Kottink, Anke I R; Melendez-Calderon, Alejandro; Buurke, Jaap H; Rietman, Johan S


    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.

  15. Verification of a computational cardiovascular system model comparing the hemodynamics of a continuous flow to a synchronous valveless pulsatile flow left ventricular assist device. (United States)

    Gohean, Jeffrey R; George, Mitchell J; Pate, Thomas D; Kurusz, Mark; Longoria, Raul G; Smalling, Richard W


    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.

  16. Aerosol assisted fabrication of carbon nanotube/zinc oxide arrays for a field emission device. (United States)

    Byeon, Jeong Hoon; Kim, Jang-Woo


    Aerosol deposition of zinc oxide (ZnO) nanoparticles was used to catalyze a silicon substrate site-selectively for a carbon nanotube (CNT) growth. An ambient spark discharge was used to produce aerosol ZnO nanoparticles, and the particle deposition on the substrate through a shadow mask was enhanced by thermophoresis. The ZnO-deposited substrate was then loaded into a chemical vapor deposition chamber, resulting in the formation of CNT/ZnO arrays. The turn-on field of an emission device constructed with the CNT/ZnO arrays was 1.7 V μm(-1) at a current of 2 μA, which was lower than that of the common CNT arrays. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Tri-leaflet valve design with a purge flow for heart-assist devices: an in vitro optimization study. (United States)

    Timmel, Tobias; Seshadri, Santhosh; Goubergrits, Leonid; Affeld, Klaus; Kertzscher, Ulrich


    The objective of this study is to assess the effect of a purge flow on valves of pulsatile heart-assist devices. Clinical applications of these devices are still limited because of frequent thromboembolic complications. These complications often originate at the valves and the unavoidable flow separation regions that are found behind the leaflets. The flow separations cause a long residence time of blood that is considered particularly detrimental. To solve this problem, a valve with a purge flow is proposed. A purge flow is a jet, which is separated from the main blood flow and directed behind the leaflets into the sinus to flush it. Even though the purge flow does not prevent a flow separation, it shortens the residence time of the blood in the sinus. Thus, the purge flow improves the periodic washout of the blood in the region of flow separation. The complex purge flow was investigated in a tri-leaflet valve. The geometrical parameters of the valve were varied systematically. A statistical technique--the Taguchi method--was used to reduce the number of investigated models to 12. The flows through the resulting valve models were numerically simulated and analyzed. The evaluated models with the best results were subsequently investigated experimentally using different methods: hemodynamic tests in a valve tester and flow visualization using the dye washout method. It was shown that the purge flow can effectively wash out the sinus. Therefore, the purge flow valve reduces the potential of a thrombus formation normally associated with the valve.

  18. 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


    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.

  19. 浅析辅具设计的社会性发展需求%Analysis of the Development Needs of the Assistive Devices Design

    Institute of Scientific and Technical Information of China (English)

    漆炫烨; 黄群


    In the industrial design under the category of auxiliary equipment design, is aimed to design something to provide people more convenient in their daily life of auxiliary products. And auxiliary equipment design can be divided into physical barriers to assist assistive devices, assist learning assistive devices, assist life assistive devices, the prevention or treatment assistive devices, and sensory handicaps assistive devices. With the development of social economy, this branch of industrial design also gradually got the attention of the people. Nowadays, in the aging of the population, we need provide the corresponding auxiliary appliance to compensate or compensatory function disorder for elderly as soon as possible, prevent and reduce disability, and the development of the assistive devices design needs to be further and more perfect, this is the important old age society's welfare services. . In this paper, we'll combine the current situation of the auxiliary equipment design and deifciency;analyze the developmental trend for future auxiliary equipment design.%在工业设计范畴中的辅具设计,旨在设计出更能方便人们生活的辅助产品。辅助产品可以分为肢体障碍协助辅具、协助学习辅具、生活辅具、预防或治疗性辅具以及感官障碍辅具。随着社会经济的发展,这一工业设计的分支也逐渐得到了人们的重视。在中国,需要及早为老年人提供相应的辅助器具以补偿或代偿功能障碍,预防和减少失能和残疾,更需要为残障人士提供帮助工作、生活的辅具,因此辅具设计、制造亟待快速发展,这是当今社会重要的福利行为。结合辅具设计的现状与不足,对辅具设计的发展趋势与发展方向进行了分析、探讨。

  20. Laser-assisted ultrathin bare die packaging: a route to a new class of microelectronic devices (United States)

    Marinov, Val R.; Swenson, Orven; Atanasov, Yuriy; Schneck, Nathan


    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 technology today can package such die onto a flexible substrate at low cost and high rate. The laser-enabled advanced packaging (LEAP) technology has been developed at the Center for Nanoscale Science and Engineering, North Dakota State University in Fargo, North Dakota, to accomplish this objective. Presented are results using LEAP to assemble dice with various thicknesses, including 350 μm/side dice as thin as 20 μm and less. To the best of our knowledge, this is the first report of using a laser to package conventional silicon dice with such small 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.

  1. Reflection removal in smart devices using a prior assisted independent components analysis (United States)

    Kalwad, Pramati; Prakash, Divya; Peddigari, Venkat; Srinivasa, Phanish


    When photographs are taken through a glass or any other semi-reflecting transparent surface, in museums, shops, aquariums etc., we encounter undesired reflection. Reflection Removal is an ill-posed problem and is caused by superposition of two layers namely the scene in front of camera and the scene behind the camera getting reflected because of the semi-reflective surface. Modern day hand held Smart Devices (smartphones, tablets, phablets, etc) are typically used for capturing scenes as they are equipped with good camera sensors and processing capabilities and we can expect image quality to be similar to a professional camera. In this direction, we propose a novel method to reduce reflection in images, which is an extension of Independent Component Analysis (ICA) approach, by making use of two cameras present - a back camera (capturing actual scene) and a front facing camera. When compared to the original ICA implementation, our method gives on an average of 10% improvement on the peak signal to noise ratio of the image.

  2. Non-invasive Brain-Computer Interfaces for Semi-autonomous Assistive Devices (United States)

    Graimann, Bernhard; Allison, Brendan; Mandel, Christian; Lüth, Thorsten; Valbuena, Diana; Gräser, Axel

    A brain-computer interface (BCI) transforms brain activity into commands that can control computers and other technologies. Because brain signals recorded non-invasively from the scalp are difficult to interpret, robust signal processing methods have to be applied. Although state-of-the-art signal processing methods are used in BCI research, the output of a BCI is still unreliable, and the information transfer rates are very small compared with conventional human interaction interfaces. Therefore, BCI applications have to compensate for the unreliability and low information content of the BCI output. Controlling a wheelchair or a robotic arm would be slow, frustrating, or even dangerous if it solely relied on BCI output. Intelligent devices, however, such as a wheelchair that can automatically avoid collisions and dangerous situations or a service robot that can autonomously conduct goal-directed tasks and independently detect and resolve safety issues, are much more suitable for being controlled by an "unreliable" control signal like that provided by a BCI.

  3. PediaFlow™ Maglev Ventricular Assist Device: A Prescriptive Design Approach. (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


    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.

  4. Watchful Waiting in Continuous-Flow Left Ventricular Assist Device Patients With Ongoing Hemolysis Is Associated With an Increased Risk for Cerebrovascular Accident or Death. (United States)

    Levin, Allison P; Saeed, Omar; Willey, Joshua Z; Levin, Charles J; Fried, Justin A; Patel, Snehal R; Sims, Daniel B; Nguyen, Jenni D; Shin, Julia J; Topkara, Veli K; Colombo, Paolo C; Goldstein, Daniel J; Naka, Yoshifumi; Takayama, Hiroo; Uriel, Nir; Jorde, Ulrich P


    Management of hemolysis in the setting of suspected device thrombosis in continuous-flow left ventricular assist device patients varies widely, ranging from watchful waiting with intensified antithrombotic therapy to early surgical device exchange. The aim of this study was to compare the outcomes of hemolysis events treated with surgical interventions versus medical management alone. A retrospective review of Heartmate II continuous-flow left ventricular assist device patients at 2 centers from January 2009 to September 2014 was completed. Patients were categorized as surgical management if hemolysis refractory to intensification of standard antithrombotic therapy was treated surgically. The primary end point was the first occurrence of cerebrovascular accident (CVA) or death. Sixty-four hemolysis events occurred in 49/367 patients implanted with Heartmate II continuous-flow left ventricular assist devices. Of 49 primary hemolysis events, 24 were treated with surgical interventions. After surgical treatment, 1 patient died and 2 experienced CVAs, as compared with 3 deaths and 9 CVAs in the 25 patients who remained on intensified antithrombotic therapy alone. The 1-year freedom from CVA or death was 87.5% and 49.5% in the surgical and medical cohorts, respectively (P=0.027). Resolution of a primary hemolysis event without CVA or death occurred in 21/24 patients treated with surgical interventions and in 13/25 who remained on medical therapy alone. A similar association between treatment and outcome was noted in the 15 recurrent hemolysis events. Hemolysis refractory to intensification of antithrombotic therapy identifies continuous-flow left ventricular assist device patients at major risk for CVA and death. Early device exchange should be considered to minimize these risks. © 2016 American Heart Association, Inc.

  5. Severely impaired von Willebrand factor-dependent platelet aggregation in patients with a continuous-flow left ventricular assist device (HeartMate II)

    DEFF Research Database (Denmark)

    Klovaite, Jolanta; Gustafsson, Finn; Mortensen, Svend A


    OBJECTIVES: This study investigated the influence of the mechanical blood pump HeartMate II (HMII) (Thoratec Corporation, Pleasanton, California) on blood coagulation and platelet function. BACKGROUND: HMII is an implantable left ventricular assist device used for the treatment of heart failure...

  6. Incidence of ventricular arrhythmias in patients on long-term support with a continuous-flow assist device (HeartMate II)

    DEFF Research Database (Denmark)

    Andersen, Mads; Videbaek, Regitze; Boesgaard, Søren;


    The incidence of ventricular tachycardia (VT) or ventricular fibrillation (VF) in patients supported with a continuous-flow left ventricular assist device (LVAD) has not been investigated in detail. In 23 consecutive recipients of a HeartMate II, we analyzed the incidence of VT/VF during a total...

  7. Cardiogenic Shock due to Psychosis-Induced Inverted Takotsubo Cardiomyopathy Bridged-to-Recovery with a Percutaneous Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Ravi Korabathina


    Full Text Available Inverted Takotsubo cardiomyopathy, a less common variant in the spectrum of stress-induced cardiomyopathy, is increasingly being reported. This report describes an acute psychiatric illness leading to the onset of this syndrome. The patient presented here developed cardiogenic shock but successfully recovered with the use of a percutaneous left ventricular assist device.

  8. Systematic Review of Studies Promoting the Use of Assistive Technology Devices by Young Children with Disabilities. Practical Evaluation Reports, Volume 5, Number 1 (United States)

    Dunst, Carl J.; Trivette, Carol M.; Hamby, Deborah W.; Simkus, Andrew


    Findings from a meta-analysis of studies investigating the use of five different assistive technology devices (switch interfaces, powered mobility, computers, augmentative communication, weighted/pressure vests) with young children with disabilities are reported. One hundred and nine studies including 1,342 infants, toddlers, and preschoolers were…

  9. Cardiogenic Shock due to Psychosis-Induced Inverted Takotsubo Cardiomyopathy Bridged-to-Recovery with a Percutaneous Left Ventricular Assist Device (United States)

    Abel, Warren; Labovitz, Arthur


    Inverted Takotsubo cardiomyopathy, a less common variant in the spectrum of stress-induced cardiomyopathy, is increasingly being reported. This report describes an acute psychiatric illness leading to the onset of this syndrome. The patient presented here developed cardiogenic shock but successfully recovered with the use of a percutaneous left ventricular assist device. PMID:28058119

  10. Roles of universal three-dimensional image analysis devices that assist surgical operations. (United States)

    Sakamoto, Tsuyoshi


    , that computer-aided diagnosis (CAD) will develop to a highly advanced level in every diagnostic field. Further, it is also expected in the treatment field that a technique coordinating various devices will be strongly required as a surgery navigator. Actually, surgery using an image navigator is being widely studied, and coordination with hardware, including robots, will also be developed. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  11. 长时间滚压泵辅助循环管理体会%The management experience of long duration roller pump ventricular assist device

    Institute of Scientific and Technical Information of China (English)

    王中; 王试福; 王大勇


    目的 总结本院51例心脏术后心脏和/或肺功能不全滚压泵长时间辅助循环(VAD)管理经验.方法 51例心脏术后患者因心脏和/或肺功能不全而难以脱离体外循环,采用滚压泵进行长时间心肺功能辅助,根据患者心肺功能状态分别采用全心辅助和单纯左心辅助两种辅助方式,辅助期间尽可能提供满意的灌注流量,重视各种脏器保护,注意维持内环境稳定,妥善调节前后负荷之间的关系.结果 全心辅助43例(其中单纯呼吸功能不全13例,全心功能不全27例,呼吸功能不全合并左心功能不全3例),单纯左心辅助8例.VAD时间360~1020(679±29)min,辅助后脱机或在IABP辅助下脱机并存活至出ICU 23例,辅助后不能脱机17例,辅助后脱机或在IABP辅助下脱机但术后10 d内死于ICU 11例.结论 心脏术后因心肺功能不全而难以脱离体外循环时应积极对衰竭器官进行辅助.选择适当辅助方式,精心进行流量调控,妥善进行前、后负荷管理,维持稳定内环境状态,可提高辅助成功率.%OBJECTIVE To summarize the management experience of long duration roller pump ventricular assist device ( VAD ) for left heart assistance in 51 post cardiac surgery patients with heart and/or lung dysfunction. METHODS Ventricular assist devices of roller pump were used for 51 patients who couldn't wean off ECC because of heart and/or lung dysfunction. According to patients' heart and lung condition, biventricular assist advice and left ventricular assist device were used respectively. During assistance,satisfactoryperfusion blood flow was provided and much attention was paid to the conservation of major organs. Body internal environment was maintained in normal status. The relationship between preload and afterload of the heart was adjusted adequately. RESULTS Biventricular assist device was used in 43 cases ( pure respiratory insufficiency 13 cases, biventricular dysfuntion 27 cases, respiratory

  12. How Should Pushing Off or the Use of Assistive Devices Be Incorporated in the Timed Up and Go for Persons With Parkinson Disease? (United States)

    Stegemöller, Elizabeth L; Schmidt, Peter; Hass, Chris; Malaty, Irene; Okun, Michael S


    To determine (1) the relationship between assisted timed Up and Go (TUG) performance and the Parkinson's Disease Questionnaire-39 (PDQ-39), and (2) whether adjusting the TUG score (adding time) improves the relationship between TUG performance and the PDQ-39 in persons with Parkinson disease (PD) who use assistive devices or push off, or both. Cross-sectional. Twenty participating National Parkinson Foundation Centers of Excellence. Data were obtained from participants (N=6624) without exclusion at the 20 participating sites. Not applicable. The relationship between TUG scores and PDQ-39 mobility scores was determined using the method of linear least squares. Adjusted scores were determined through minimizing the sum of the squared error. The correlation between assisted TUG scores and PDQ-39 mobility scores was slightly lower (R(2)=.384) compared with the correlation between nonassisted TUG scores and PDQ-39 mobility scores (R(2)=.409). Adjusting assisted TUG performance scores for push off and for use of an assistive device resulted in a modest increase in correlation (R(2)=.399). Applying adjustments to assisted TUG may provide clinically important information for evaluating balance, mobility, and falls, and for determining the most effective therapeutic strategies for persons with PD. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  13. Outpatient management of intra-corporeal left ventricular assist device system in children: a multi-center experience. (United States)

    Schweiger, M; Vanderpluym, C; Jeewa, A; Canter, C E; Jansz, P; Parrino, P E; Miera, O; Schmitto, J; Mehegan, M; Adachi, I; Hübler, M; Zimpfer, D


    Little is known about the outcomes of children supported on intracorporeal left ventricular assist device (HVAD), and the feasibility of outpatient management. All centers with pediatric patients discharged from the hospital on the device were identified using company database. A total of 14 centers were contacted, with 9 centers, contributing data retrospectively. From 2011 to 2013, 12 pediatric patients (7 females), mean aged 11.9 ± 2.3 years (range 8-15), mean weight 43 ± 19 kg (range 18-81), mean body surface area 1.3 ± 0.3 m(2) (range 0.76-1.96) were identified. Diagnosis included: dilated cardiomyopathy (CMP) (n = 5), noncompaction CMP (n = 4), toxic CMP (n = 2) and viral CMP (n = 1). Indications for support were permanent support (n = 1), bridge to recovery (n = 1) and bridge to transplantation (n = 10). Prior to HVAD implantation, all patients received intravenous inotropes and two patients were on temporary mechanical support. Overall mortality was 0%. Mean duration of inpatient and outpatient support were 56 (range: 19-95 days) and 290 days (range: 42-790), respectively. Mean readmission rate was 0.02 per patient month (2.1 per patient). No adverse events involving emergency department occurred. Eight children resumed local schooling. Home discharge of children supported on HVAD is feasible and safe. School integration can be achieved. There is wide center variability to discharge practice for children.

  14. Economic Evaluation of Left Ventricular Assist Devices for Patients With End Stage Heart Failure Who Are Ineligible for Cardiac Transplantation. (United States)

    Chew, Derek S; Manns, Braden; Miller, Robert J H; Sharma, Nakul; Exner, Derek V


    Continuous flow (CF) left ventricular assist devices (LVADs) improve survival in end-stage heart failure patients who are ineligible for cardiac transplantation. Their use in this population (referred to as destination therapy) is increasing in many countries, yet they are not routinely funded for this indication in Canada. We assessed the cost-effectiveness of destination therapy CF-LVADs from the perspective of the Canadian health care payer. A Markov model was used to project the outcomes and costs of 2 treatment pathways, CF-LVAD implantation and medical management alone, in an end-stage heart failure patient cohort ineligible for transplantation. Clinical and cost input estimates were informed from the available literature. Model outcomes included costs (in 2015 Canadian dollars), quality-adjusted life-years (QALYs), and the cost per QALY gained. Compared with medical management, CF-LVAD patients had higher costs ($284,287 vs $31,984) and QALYs (1.48 vs 0.39) over a lifetime horizon. The incremental cost per QALY gained was $230,692. The model was most sensitive to device implantation costs, and the clinical effectiveness of CF-LVADs on survival and quality of life. A scenario analysis using contemporary survival data resulted in a cost per QALY gained of $125,936. When applying contemporary LVAD survival trends, the model showed that the cost of initial LVAD implantation needed to be less than $123,000 to be considered cost-effective. The incremental cost per QALY for destination therapy CF-LVADs is predicted to be above usual thresholds for funding in Canada. In some plausible scenarios, its cost-effectiveness is similar to dialysis for kidney failure, a therapy that is also immediately life-saving. Because of this, there will be likely ongoing pressure to fund CF-LVADs for a subset of patients ineligible for transplantation. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  15. Telemonitoring and Medical Care of Heart Failure Patients Supported by Left Ventricular Assist Devices - The Medolution Project. (United States)

    Reiss, Nils; Schmidt, Thomas; Müller-von Aschwege, Frerk; Thronicke, Wolfgang; Hoffmann, Jan-Dirk; Röbesaat, Jenny Inge; Deniz, Ezin; Hein, Andreas; Krumm, Heiko; Stewing, Franz-Josef; Willemsen, Detlev; Schmitto, Jan Dieter; Feldmann, Christina


    Long-term survival after left ventricular assist device (LVAD) implantation in heart failure patients is mainly determined by a sophisticated after-care. Ambulatory visits only take place every 12 weeks. In case of life-threatening complications (pump thrombosis, driveline infection) this might lead to delayed diagnosis and delayed intervention. It is the intention of the international project Medolution (Medical care evolution) to develop new approaches in order to create best structures for telemonitoring of LVAD patients. In the very early period of the project a questionnaire was sent to 180 LVAD patients to evaluate the need and acceptance of telemonitoring. Thereafter, a graphical user interface (GUI) mockup was developed as one of the first steps to improve the continuous contact between the LVAD patient and the physician. As a final goal the Medolution project aims to bundle all relevant informations from different data sources into one platform in order to provide the physician a comprehensive overview of a patient's situation. In the systems background a big data analysis should run permanently and should try to detect abnormalities and correlations as well. At crucial events, a notification system should inform the physician and should provide the causing data via a decision support system. With this new system we are expecting early detection and prevention of common and partially life-threatening complications, less readmissions to the hospital, an increase in quality of life for the patients and less costs for the health care system as well.

  16. Early feasibility testing and engineering development of a sutureless beating heart connector for left ventricular assist devices. (United States)

    Koenig, Steven C; Jimenez, Jorge H; West, Seth D; Sobieski, Michael A; Choi, Young; Monreal, Gretel; Giridharan, Guruprasad A; Soucy, Kevin G; Slaughter, Mark S


    APK Advanced Medical Technologies (Atlanta, GA) is developing a sutureless beating heart (SBH) left ventricular assist device (LVAD) connector system consisting of anchoring titanium coil, titanium cannula with integrated silicone hemostatic valve, coring and delivery tool, and LVAD locking mechanism to facilitate LVAD inflow surgical procedures. Feasibility testing was completed in human cadavers (n = 4) under simulated normal and hypertensive conditions using saline to observe seal quality in degraded human tissue and assess anatomic fit; acutely in ischemic heart failure bovine model (n = 2) to investigate short-term performance and ease of use; and chronically for 30 days in healthy calves (n = 2) implanted with HeartWare HVAD to evaluate performance and biocompatibility. Complete hemostasis was achieved in human cadavers and animals at LV pressures up to 170 mm Hg. In animals, off-pump (no cardiopulmonary bypass) anchoring of the connector was accomplished in less than 1 minute with no residual bleeding after full delivery and locking of the LVAD; and implant of connector and LVAD were successfully completed in under 10 minutes with total procedure blood loss less than 100 ml. In chronic animals before necropsy, no signs of leakage or disruption at the attachment site were observed at systolic LV pressures >200 mm Hg.

  17. Flow visualization of a monoleaflet and bileaflet mechanical heart valve in a pneumatic ventricular assist device using a PIV system. (United States)

    Lee, Hwansung; Tatsumi, Eisuke; Taenaka, Yoshiyuki


    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.

  18. Osteopathic treatment in a patient with left-ventricular assist device with left brachialgia: a case report

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    Bordoni B


    Full Text Available Bruno Bordoni,1–3 Fabiola Marelli,2,3 Bruno Morabito,2–4 Beatrice Sacconi5 1Foundation Don Carlo Gnocchi IRCCS, Department of Cardiology, Institute of Hospitalization and Care with Scientific Address, Milan, 2CRESO, School of Osteopathic Centre for Research and Studies, Gorla Minore, 3CRESO, School of Osteopathic Centre for Research and Studies, Falconara Marittima, 4Department of Radiological, Oncological and Anatomopathological Sciences, Sapienza University of Rome, 5Center for Life Nano Science, CLNS@Sapienza, Istituto Italiano di Tecnologia, Rome, Italy Abstract: This study deals with an osteopathic approach used for a patient with left-ventricular assist device (L-VAD affected by left brachialgia. Clinical examination revealed the presence of thoracic outlet syndrome and pectoralis minor syndrome, with compression of the left proximal ulnar nerve, related to the surgical sternotomy performed. The osteopathic techniques used can be classified as indirect and direct, addressed to the pectoralis minor and the first left rib, respectively. To our knowledge, this is the first text in literature with an osteopathic treatment in a patient with L-VAD. Keywords: osteopathic, L-VAD, thoracic outlet syndrome, TOS, myofascial, fascia

  19. A new transcutaneous energy transmission system with hybrid energy coils for driving an implantable biventricular assist device. (United States)

    Okamoto, Eiji; Yamamoto, Yoshiro; Akasaka, Yuhta; Motomura, Tadashi; Mitamura, Yoshinori; Nosé, Yukihiko


    We have developed a new transcutaneous energy transmission (TET) system for a totally implantable biventricular assist device (BVAD) system in the New Energy and Industrial Development Organization (NEDO) artificial heart project. The TET system mainly consists of an energy transmitter, a hybrid energy coil unit, an energy receiver, an internal battery system, and an optical telemetry system. The hybrid energy coil unit consists of an air-core energy transmission coil and an energy-receiving coil having a ferrite core. Internal units of the TET system are encapsulated in a titanium alloy casing, which has a size of 111 mm in width, 73 mm in length, and 25 mm in height. In in vitro experiments, the TET system can transmit a maximum electric energy of 60 Watts, and it has a maximum transmission efficiency of 87.3%. A maximum surface temperature of 46.1 degrees C was measured at the ferrite core of the energy-receiving coil during an energy transmission of 20 Watts in air. The long-term performance test shows that the TET system has been able to operate stably for over 4 years with a decrease of energy-transmission efficiency from 85% to 80%. In conclusion, the TET system with the hybrid energy coil can overcome the drawback of previously reported TET systems, and it promises to be the highest performance TET system in the world.

  20. Dosing of vancomycin in patients with continuous-flow left ventricular assist devices: a clinical pharmacokinetic analysis. (United States)

    Jennings, Douglas L; Makowski, Charles T; Chambers, Rachel M; Lanfear, David E


    To describe the pharmacokinetics of vancomycin in patients with continuous-flow left ventricular assist devices (CF-LVADs). Eligible patients were ≥18 years old, implanted with a Heart Mate II CF-LVAD during January 2008-April 2012, and treated with vancomycin ≥48 hours for infection. Key exclusion criteria were unstable renal function, acute heart failure exacerbation, hemodynamic instability, and recent surgery. First-order elimination rate constant (Ke) and volume of distribution (Vd) were estimated using ideal (IBW), adjusted (AdjBW), actual (ABW), and fixed body weights. Estimated parameters were compared with measured pharmacokinetic parameters, which were calculated from steady state peak and trough vancomycin levels using one-compartment model equations. Twelve patients were included (age 44.9 ± 15 years, 91.7% male, 58.3% obese, CLcr 79.2 ± 27 mL ∙ min⁻¹). Common treatment indications were health-care associated pneumonia (41.7%), driveline infection (25%), and sepsis (16.7%). All methods of predicting Ke provided overestimates (pABW in obese patients yielded overestimates of 74.5% (p<0.05), where IBW predictive Vd equations provided accurate assessments regardless of body habitus. General population methods may not accurately estimate the pharmacokinetic parameters of vancomycin for compensated heart failure patients implanted with CF-LVADs.

  1. Left ventricular assist device support with a centrifugal pump for 2 months in a 5-kg child. (United States)

    Inoue, Takafumi; Nishimura, Takashi; Murakami, Arata; Itatani, Keiichi; Takaoka, Tetsuhiro; Kitahori, Kazuo; Umeki, Akihide; Takezoe, Toshiko; Kashiwa, Koichi; Kyo, Shunei; Ono, Minoru


    The mid-term and long-term results of left ventricular assist device (LVAD) implantation for small children are still unsatisfactory. There have been few reports of LVAD implantation for more than a month in children weighing under 5 kg. We report the case of a 4-month-old female infant who survived for 2 months after being diagnosed with dilated cardiomyopathy (DCM) with extracorporeal centrifugal pump support. In recent years, although pumps designed for small children have been introduced and are used as a bridge to transplantation or recovery, mid-term or long-term mechanical support for small children with heart failure is still difficult. We managed to successfully provide support for a low-body-weight child with a centrifugal pump over a mid-term period. We achieved acceptable control of thrombosis, but eventually the infant died of sepsis. Autopsy revealed no prominent thrombosis in the perfusion cannula, drainage cannula, the pump, or the left ventricle. This is the first case report of LVAD support with the centrifugal pump, ROTAFLOW(®) (Maquet, Rastatt, Germany), for 2 months in a child weighing under 5 kg. Our method may potentially save severe heart failure children who need mid-term LVAD support.

  2. Constrictive Pericarditis in the Presence of Remaining Remnants of a Left Ventricular Assist Device in a Heart Transplanted Patient

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    R. Rivinius


    Full Text Available Constrictive pericarditis (CP is a severe subform of pericarditis with various causes and clinical findings. Here, we present the unique case of CP in the presence of remaining remnants of a left ventricular assist device (LVAD in a heart transplanted patient. A 63-year-old man presented at the Heidelberg Heart Center outpatient clinic with progressive dyspnea, fatigue, and loss of physical capacity. Heart transplantation (HTX was performed at another heart center four years ago and postoperative clinical course was unremarkable so far. Pharmacological cardiac magnetic resonance imaging (MRI stress test was performed to exclude coronary ischemia. The test was negative but, accidentally, a foreign body located in the epicardial adipose tissue was found. The foreign body was identified as the inflow pump connection of an LVAD which was left behind after HTX. Echocardiography and cardiac catheterization confirmed the diagnosis of CP. Surgical removal was performed and the epicardial tubular structure with a diameter of 30 mm was carefully removed accompanied by pericardiectomy. No postoperative complications occurred and the patient recovered uneventfully with a rapid improvement of symptoms. On follow-up 3 and 6 months later, the patient reported about a stable clinical course with improved physical capacity and absence of dyspnea.

  3. Physical therapist management of patients with ventricular assist devices: key considerations for the acute care physical therapist. (United States)

    Wells, Chris L


    This article provides an overview of the utilization of ventricular assist devices (VADs), reviews the common features of VADs and management of VAD recipients, discusses clinical considerations in the rehabilitation process, and describes the role of the acute care physical therapist in the care of VAD recipients. With more than 5 million people in the United States with heart failure, and with a limited ability to manage the progressive and debilitating nature of heart failure, VADs are becoming more commonplace. In order to prescribe a comprehensive and effective plan of care, the physical therapist needs to understand the type and function of the VADs and the goals of the VAD program. The goals for the physical therapist are: (1) to deliver comprehensive rehabilitation services to patients on VAD support, (2) to develop an understanding of the role of functional mobility in recovery, and (3) to understand how preoperative physical function may contribute to the VAD selection process. The acute care physical therapist has an increasing role in providing a complex range of rehabilitation services, as well as serving as a well-educated resource to physical therapists across the health care spectrum, as more VAD recipients are living in the community.

  4. Assessment of Bleeding and Thrombosis Based on Aspirin Responsiveness after Continuous-Flow Left Ventricular Assist Device Placement. (United States)

    Floroff, Catherine K; Rieger, Krista L; Veasey, Tara M; Strout, Sara E; DeNino, Walter F; Meadows, Holly B; Stroud, Martha R; Toole, John M; Heyward, Dawn P; Brisco, Meredith A; Cook, Jennifer L; Lazarchick, John; Uber, Walter E


    Pump thrombosis (PT) is a severe complication of left ventricular assist device (LVAD) support. This study evaluated PT and bleeding following LVAD placement in patients responsive to a standard aspirin dose of 81 mg using platelet inhibition monitoring compared with initial non-responders who were then titrated upward to achieve therapeutic response.Patients ≥ 18 years of age with initial placement of HeartMate II® (HMII) LVAD at our institution and at least one VerifyNow® Aspirin test performed during initial hospitalization were included. The primary endpoints were bleeding and PT compared between initial aspirin responders and non-responders.Of 85 patients, 19 (22%) were nonresponsive to initial aspirin therapy. Responders and non-responders showed similar survival (p=0.082), freedom from suspected/confirmed PT (p=0.941), confirmed PT (p=0.273), bleeding (p=0.401), and incidence rates in PT and bleeding. Among the initial responders (<500 vs 500 - 549 aspirin reaction units), there were no significant differences in survival (p = 0.177), freedom from suspected/confirmed PT (p=0.542), confirmed PT (p=0.159), bleeding (p=0.879) and incidence of PT and bleeding.Platelet function testing may detect resistance to standard aspirin regimens used in LVAD patients. Dose escalation in initially nonresponsive patients to achieve responsiveness may confer a similar PT risk to patients initially responsive to standard aspirin dosing without increased bleeding risk.

  5. Single axis controlled hybrid magnetic bearing for left ventricular assist device: hybrid core and closed magnetic circuit. (United States)

    da Silva, Isaias; Horikawa, Oswaldo; Cardoso, Jose R; Camargo, Fernando A; Andrade, Aron J P; Bock, Eduardo G P


    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.

  6. Aluminum electrode modulated bipolar resistive switching of Al/fuel-assisted NiOx/ITO memory devices modeled with a dual-oxygen-reservoir structure. (United States)

    Chiang, Kun-Keng; Chen, Jen-Sue; Wu, Jih-Jen


    Bipolar resistive switching in Al/fuel-assisted NiO(x) (40 nm)/ITO devices is demonstrated in this work. XPS analysis reveals the simultaneous presence of metallic Ni, Ni(2)O(3), and NiO components in the fuel-assisted NiO(x). The concentration, as well as spreading of the metallic Ni and accompanying oxygen vacancies, are related to the Al/NiO(x) interfacial reaction, which is enhanced by the increasing thickness of the Al top electrode. Correspondingly, the preswitching-on voltage decreases while the preswitching-off voltage increases with increasing thickness (from 15 to 60 nm) of Al. However, in regular switching operation, set and reset voltages are considerably lowered for devices with an increased thickness of the Al top electrode. The bipolar resistive switching behaviors of Al/fuel-assisted NiO(x)/ITO devices are therefore discussed based on the formation of conductive paths and their correlation with the Al-electrode modulated composition in the fuel-assisted NiO(x). The Al/NiO(x) interfacial reaction region pairs with ITO to form a dual-oxygen-reservoir structure. Mechanisms of construction/destruction of conducting paths originating from the electrochemical redox reactions at the interface between NiO(x), and the dual oxygen reservoirs will also be explicated.

  7. 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. (United States)

    Bishop, Lauri; Khan, Moiz; Martelli, Dario; Quinn, Lori; Stein, Joel; Agrawal, Sunil


    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.


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    Carlos Eugenio Oliveros Tascón


    -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.

  9. Participatory organizational intervention for improved use of assistive devices for patient transfer: study protocol for a single-blinded cluster randomized controlled trial. (United States)

    Jakobsen, Markus D; Aust, Birgit; Dyreborg, Johnny; Kines, Pete; Illum, Maja B; Andersen, Lars L


    Epidemiological studies have shown that patient transfer is a risk factor for back pain, back injuries and long term sickness absence, whereas consistent use of assistive devices during patient transfer seems to be protective. While classical ergonomic interventions based on education and training in lifting and transferring techniques have not proven to be effective in preventing back pain, participatory ergonomics, that is meant to engage and motivate the involved parties while at the same time making the intervention maximally relevant, may represent a better solution. However, these findings are largely based on uncontrolled studies and thus lack to be confirmed by studies with better study designs. In this article, we present the design of a study which aims to evaluate the effect and process of a participatory organizational intervention for improved use of assistive devices. The study was performed as a cluster randomized controlled trial. We recruited 27 departments (clusters) from five hospitals in Denmark to participate in the study. Prior to randomization, interviews, observations and questionnaire answers (baseline questionnaire) were collected to gain knowledge of barriers and potential solutions for better use of assistive devices. In April 2016, the 27 departments were randomly allocated using a random numbers table to a participatory intervention (14 clusters, 324 healthcare workers) or a control group (13 clusters, 318 healthcare workers). The participatory intervention will consist of workshops with leaders and selected healthcare workers of each department. Workshop participants will be asked to discuss the identified barriers, develop solutions for increasing the use of assistive devices and implement them in their department. Use of assistive devices (using digital counters -, primary outcome, and accelerometers and questionnaire - secondary outcome), perceived physical exertion during patient transfer, pain intensity in the lower back

  10. A Bayesian Model to Predict Right Ventricular Failure Following Left Ventricular Assist Device Therapy. (United States)

    Loghmanpour, Natasha A; Kormos, Robert L; Kanwar, Manreet K; Teuteberg, Jeffrey J; Murali, Srinivas; Antaki, James F


    This study investigates the use of a Bayesian statistical model to address the limited predictive capacity of existing risk scores derived from multivariate analyses. This is based on the hypothesis that it is necessary to consider the interrelationships and conditional probabilities among independent variables to achieve sufficient statistical accuracy. Right ventricular failure (RVF) continues to be a major adverse event following left ventricular assist device (LVAD) implantation. Data used for this study were derived from 10,909 adult patients from the Inter-Agency Registry for Mechanically Assisted Circulatory Support (INTERMACS) who had a primary LVAD implanted between December 2006 and March 2014. An initial set of 176 pre-implantation variables were considered. RVF post-implant was categorized as acute (14 days) in onset. For each of these endpoints, a separate tree-augmented naïve Bayes model was constructed using the most predictive variables employing an open source Bayesian inference engine. The acute RVF model consisted of 33 variables including systolic pulmonary artery pressure (PAP), white blood cell count, left ventricular ejection fraction, cardiac index, sodium levels, and lymphocyte percentage. The early RVF model consisted of 34 variables, including systolic PAP, pre-albumin, lactate dehydrogenase level, INTERMACS profile, right ventricular ejection fraction, pro-B-type natriuretic peptide, age, heart rate, tricuspid regurgitation, and body mass index. The late RVF model included 33 variables and was predicted mostly by peripheral vascular resistance, model for end-stage liver disease score, albumin level, lymphocyte percentage, and mean and diastolic PAP. The accuracy of all Bayesian models was between 91% and 97%, with an area under the receiver operator characteristics curve between 0.83 and 0.90, sensitivity of 90%, and specificity between 98% and 99%, significantly outperforming previously published risk scores. A Bayesian prognostic

  11. Exercise physiology with a left ventricular assist device: Analysis of heart-pump interaction with a computational simulator. (United States)

    Fresiello, Libera; Rademakers, Frank; Claus, Piet; Ferrari, Gianfranco; Di Molfetta, Arianna; Meyns, Bart


    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. Device-Training for Individuals with Thoracic and Lumbar Spinal Cord Injury Using a Powered Exoskeleton for Technically Assisted Mobility: Achievements and User Satisfaction. (United States)

    Platz, Thomas; Gillner, Annett; Borgwaldt, Nicole; Kroll, Sylvia; Roschka, Sybille


    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.

  13. A new device for magnetic stirring-assisted dispersive liquid-liquid microextraction of UV filters in environmental water samples. (United States)

    Zhang, Ping-Ping; Shi, Zhi-Guo; Yu, Qiong-Wei; Feng, Yu-Qi


    A new method based on dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid chromatography (HPLC) has been developed for the analysis of UV filters. A specially designed flask, which has two narrow open necks with one of them having a capillary tip, was employed to facilitate the DLLME process. By adopting such a device, the extraction and subsequent phase separation were conveniently achieved. A binary solvent system of water sample and low-density extraction solvent (1-octanol) was used for the DLLME and no disperser solvent was involved. The extraction was accelerated by magnetic agitation of the two phases. After extraction, phase separation of the extraction solvent from the aqueous sample was easily achieved by leaving the extraction system statically for a while. No centrifugation step involving in classical DLLME was necessary. The analyte-enriched phase, floating above the sample solution, was elevated and concentrated into the narrow open tip of the flask by adding pure water into it via the other port, which was withdrawn with a microsyringe for the subsequent HPLC analysis. Under the optimized conditions, the limits of detection for the analytes were in range of 0.2-0.8ngmL(-1) .The linearity ranges were 8-20,000 ng mL(-1) for HB, 7-20,000 ng mL(-1) for DB, 8-10,000 ng mL(-1) for BP and 5-20,000 ng mL(-1) for HMB, respectively. Enrichment factors ranging from 59 to 107 folders were obtained for the analytes. The relative standard deviations (n=3) at a spiked level of 80 ng mL(-1) were between 1.4 and 4.8%. The proposed magnetic stirring-assisted DLLME method was successfully applied to the analysis of lake water samples.

  14. Myocardial atrophy and chronic mechanical unloading of the failing human heart: implications for cardiac assist device-induced myocardial recovery. (United States)

    Diakos, Nikolaos A; Selzman, Craig H; Sachse, Frank B; Stehlik, Josef; Kfoury, Abdallah G; Wever-Pinzon, Omar; Catino, Anna; Alharethi, Rami; Reid, Bruce B; Miller, Dylan V; Salama, Mohamed; Zaitsev, Alexey V; Shibayama, Junko; Li, Hui; Fang, James C; Li, Dean Y; Drakos, Stavros G


    In animal models of heterotopic transplantation, mechanical unloading of the normal, nonhypertrophic heart results in atrophy. Primarily on the basis of these animal data, the notion that chronic left ventricular assist device (LVAD)-induced unloading will result in atrophy has dominated the clinical heart failure field, and anti-atrophic drugs have been used to enhance the cardiac recovery potential observed in some LVAD patients. However, whether unloading-induced atrophy in experimental normal heart models applies to failing and hypertrophic myocardium in heart failure patients unloaded by continuous-flow LVADs has not been studied. The study examined whether mechanical unloading by continuous-flow LVAD leads to myocardial atrophy. We prospectively examined myocardial tissue and hemodynamic and echocardiographic data from 44 LVAD patients and 18 untransplanted normal donors. Cardiomyocyte size (cross-sectional area) decreased after LVAD unloading from 1,238 ± 81 μm(2) to 1,011 ± 68 μm(2) (p = 0.001), but not beyond that of normal donor hearts (682 ± 56 μm(2)). Electron microscopy ultrastructural evaluation, cardiomyocyte glycogen content, and echocardiographic assessment of myocardial mass and left ventricular function also did not suggest myocardial atrophy. Consistent with these findings, t-tubule morphology, cytoplasmic penetration, and distance from the ryanodine receptor were not indicative of ongoing atrophic remodeling during LVAD unloading. Molecular analysis revealed no up-regulation of proatrophic genes and proteins of the ubiquitin proteasome system. Structural, ultrastructural, microstructural, metabolic, molecular, and clinical functional data indicated that prolonged continuous-flow LVAD unloading does not induce hypertrophy regression to the point of atrophy and degeneration. These findings may be useful in designing future investigations that combine LVAD unloading and pharmaceutical therapies as a bridge to recovery of the failing heart

  15. Is device-assisted reduction prior to semi-extended intramedullary nailing of distal tibial fractures necessary? (United States)

    Mehta, Nisarg; Selvaratnam, Veenesh; Giotakis, Nikolaos; Narayan, Badri


    Traditional methods of nailing distal tibial fractures have an unacceptable risk of mal-alignment due to difficulty in obtaining and maintaining reduction intra-operatively. Methods to obtain and maintain reduction when nailing these fractures, and therefore reducing the risk of Mal-alignment include modified external fixators, distractors and commercial reduction tools. Semi-extended intramedullary nailing of distal tibial fractures via a supra-patellar approach is now being used more commonly. The aim of this study was to assess whether a commercial reduction device (Staffordshire Orthopaedic Reduction Machine - STORM, Intelligent Orthopaedics, Stafffordshire, UK) is necessary to reduce the risk of mal-alignment in patients undergoing semi-extended nailing for distal tibial fractures. A case-control study was conducted in 20 patients who had STORM-assisted reduction of distal tibial fractures prior to intramedullary nailing and 20 controls without STORM. The control group was matched for age, sex, fracture type (AO/OTA), ASA and gender. All patients had an intramedullary nail (IMN) using the semi-extended system. Primary outcome measures were coronal and sagittal mal-alignment. Secondary outcome measure was unplanned return to theatre for complications and problems with fracture healing. There was no difference in post-operative mal-alignment in both groups. There was no significant difference in time to union in both groups Both groups had equal number of patients requiring unplanned return to theatre. The STORM group was associated with a significantly increased operative time [p=0.007, 130.3min (SD 49.4) STORM vs 95.6 mins (SD 22.9) Control]. Intraoperative use of STORM significantly increases operative time with no difference in outcome. The superior orthogonal views and manual control obtained during semi-extended nailing via a supra-patellar approach obviate the need for additional methods: of intraoperative reduction for this fracture group. Copyright

  16. Exercise hemodynamics during extended continuous flow left ventricular assist device support: the response of systemic cardiovascular parameters and pump performance. (United States)

    Martina, Jerson; de Jonge, Nicolaas; Rutten, Marcel; Kirkels, J Hans; Klöpping, Corinne; Rodermans, Ben; Sukkel, Eveline; Hulstein, Nelienke; Mol, Bas; Lahpor, Jaap


    Patients on continuous flow left ventricular assist devices (cf-LVADs) are able to return to an active lifestyle and perform all sorts of physical activities. This study aims to evaluate exercise hemodynamics in patients with a HeartMate II cf-LVAD (HM II). Thirty (30) patients underwent a bicycle exercise test. Along with exercise capacity, systemic cardiovascular responses and pump performance were evaluated at 6 and 12 months after HM II implantation. From rest to maximum exercise, heart rate increased from 87 ± 14 to 140 ± 32 beats/minute (bpm) (P<0.01), while systolic arterial blood pressure increased from 93 ± 12 to 116 ± 21 mm Hg (P<0.01). Total cardiac output (TCO) increased from 4.1 ± 1.1 to 8.5 ± 2.8 L/min (P<0.01) while pump flow increased less, from 5.1 ± 0.7 to 6.4 ± 0.6 L/min (P<0.01). Systemic vascular resistance (SVR) decreased from 1776 ± 750 to 1013 ± 83 dynes.s/cm(5) (P<0.001) and showed the strongest correlation with TCO (r= -0.72; P<0.01). Exercise capacity was affected by older age, while blood pressure increased significantly in men compared with women. Exercise capacity remained consistent at 6 and 12 months after HM II implantation, 51% ± 13% and 52% ± 13% of predicted VO2 max for normal subjects corrected for age and gender. In conclusion, pump flow of the HM II may contribute partially to TCO during exercise, while SVR was the strongest determinant of TCO.

  17. [Proposal for updated listing criteria for heart transplantation and indications to implant of left ventricular assist devices]. (United States)

    Ammirati, Enrico; Oliva, Fabrizio; Colombo, Tiziano; Botta, Luca; Cipriani, Manlio; Cannata, Aldo; Verde, Alessandro; Turazza, Fabio M; Russo, Claudio F; Paino, Roberto; Martinelli, Luigi; Frigerio, Maria


    Heart transplantation (HTx) is considered to be the gold standard treatment for advanced heart failure (HF) but it is available only for a minority of patients, due to paucity of donor hearts (278 HTx were performed in 2011 in Italy). Patients listed for HTx have a prolonged waiting time (that is about 2.3 years in the 2006-2010 time period in Italy) that is superior compared with patients who receive HTx (median time around 6 months), to underline the presence of an allocation system that prioritizes candidates in critical conditions. Patients listed for HTx have a poor quality of life and their annual mortality is around 8-10%. Another 10-15% of HTx candidates are removed from the waiting list each year because they are no longer suitable for transplantation. On the other hand, continuous-flow left ventricular assist devices (LVADs) have been demonstrated to improve survival and quality of life of patients with advanced/refractory HF. LVAD therapy can represent a valid alternative to HTx, and it is recommended for patients with advanced HF in the recent edition of the European Society of Cardiology guidelines on HF management. In the United States, a larger number of centers compared with European ones started to apply a strategy of LVAD implant for many patients who meet clinical criteria for listing for HTx. Data from our center concerning the last 6 years of LVAD implant (51 implants since 2006) reported a 75.5% survival rate at 1 year. In Italian series, as in our center, current HTx survival is only slightly superior (83% survival rate at 1 year), based on data from the Italian National Transplant Center. We report a proposal for updated listing criteria for HTx and indications for LVAD implant in patients with advanced acute and chronic HF. Criteria for identifying suitable patients for HTx and/or LVAD considering the shortage of donors are discussed.

  18. 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


    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.

  19. 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;


    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 t......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...... (F = 10.71, p = .001) but poorer mental health status (F = 14.82, p 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...... patients show higher distress levels compared to caregivers of ICD patients. LVAD partners may have a need for support beyond what is offered currently in clinical practice....

  20. Y stenting assisted coiling using a new low profile visible intraluminal support device for wide necked basilar tip aneurysms: a technical report. (United States)

    Conrad, Marcelo D; Brasiliense, Leonardo B C; Richie, Alexa N; Hanel, Ricardo A


    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.

  1. 49 CFR 39.93 - What wheelchairs and other assistive devices may passengers with a disability bring onto a... (United States)


    ... permit the use of other power-driven mobility devices by individuals with mobility disabilities, unless you can demonstrate that a device cannot be operated on board the vessel consistent with legitimate... power-driven mobility device can be allowed on a specific vessel as a reasonable modification...

  2. Does reduced movement restrictions and use of assistive devices affect rehabilitation outcome after total hip replacement? A non-randomized, controlled study in 365 patients with six week follow up

    DEFF Research Database (Denmark)

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

    a standard package of assistive devices (restricted group, RG). This group was compared to patients included into the study the following 3 months with a less restricted hip movement regime and use of assistive devices according to individual needs (unrestricted group, UG). Questionnaires on function...... (difference ≤5 points). Yet, there is a beneficial or equal effect of the unrestricted regime concerning secondary outcomes. It seems possible to reduce the use of assistive devices considerably and thereby induce cost savings. More research on safety issues is needed to elucidate the effect of unrestricted...

  3. Effect of Left Ventricular Assist Device Implantation and Heart Transplantation on Habitual Physical Activity and Quality of Life☆ (United States)

    Jakovljevic, Djordje G.; McDiarmid, Adam; Hallsworth, Kate; Seferovic, Petar M.; Ninkovic, Vladan M.; Parry, Gareth; Schueler, Stephan; Trenell, Michael I.; MacGowan, Guy A.


    The present study defined the short- and long-term effects of left ventricular assist device (LVAD) implantation and heart transplantation (HT) on physical activity and quality of life (QoL). Forty patients (LVAD, n = 14; HT, n = 12; and heart failure [HF], n = 14) and 14 matched healthy subjects were assessed for physical activity, energy expenditure, and QoL. The LVAD and HT groups were assessed postoperatively at 4 to 6 weeks (baseline) and 3, 6, and 12 months. At baseline, LVAD, HT, and HF patients demonstrated low physical activity, reaching only 15%, 28%, and 51% of that of healthy subjects (1,603 ± 302 vs 3,036 ± 439 vs 5,490 ± 1,058 vs 10,756 ± 568 steps/day, respectively, p <0.01). This was associated with reduced energy expenditure and increased sedentary time (p <0.01). Baseline QoL was not different among LVAD, HT, and HF groups (p = 0.44). LVAD implantation and HT significantly increased daily physical activity by 60% and 52%, respectively, from baseline to 3 months (p <0.05), but the level of activity remained unchanged at 3, 6, and 12 months. The QoL improved from baseline to 3 months in LVAD implantation and HT groups (p <0.01) but remained unchanged afterward. At any time point, HT demonstrated higher activity level than LVAD implantation (p <0.05), and this was associated with better QoL. In contrast, physical activity and QoL decreased at 12 months in patients with HF (p <0.05). In conclusion, patients in LVAD and HT patients demonstrate improved physical activity and QoL within the first 3 months after surgery, but physical activity and QoL remain unchanged afterward and well below that of healthy subjects. Strategies targeting low levels of physical activity should now be explored to improve recovery of these patients. PMID:24925802

  4. A software tool for the input and management of phenotypic data using personal digital assistants and other mobile devices. (United States)

    Köhl, Karin; Gremmels, Jürgen


    Plant breeding and genetics demand fast, exact and reproducible phenotyping. Efficient statistical evaluation of phenotyping data requires standardised data storage ensuring long-term data availability while maintaining intellectual property rights. This is state of the art at phenomics centres, which, however, are unavailable for most scientists. For them we developed a simple and cost-efficient system, the Phenotyper, which employs mobile devices or personal digital assistants (PDA) for on-site data entry and open-source software for data management. A graphical user interface (GUI) on a PDA replaces paper-based form sheet and data entry on a desktop. The user can define his phenotyping schemes in a web tool without in-depth knowledge of the system and thus adjust it more easily to new research aspects than in a classical laboratory information management system (LIMS). In the Phenotyper, schemes are built from controlled vocabulary gained from published ontologies. Vocabulary and schemes are stored in a database that also manages the user access. From the web page, schemes are downloaded as extended markup language (XML) files for the transfer to the PDA and the exchange between users. On the PDA, the GUI displays the schemes and stores data in comma separated value format and XML format. After manual quality control, data are uploaded via a web page to an independently hosted results database, in which data are stored in an entity-attribute-value structure to provide maximum flexibility. Datasets are linked to the original and curated data files stored on a file server. The ownership stamp, project affiliation and date stamp of a dataset are used to regulate data access, which is restricted to data belonging to the user or to his projects and data, for which the embargo period has ended. By export of standardised ASCII reports to long-term data storage facility, long-term accessibility allows searching, citing and use of raw data beyond the lifetime of the

  5. Use of activated recombinant factor VII for severe coagulopathy post ventricular assist device or orthotopic heart transplant

    Directory of Open Access Journals (Sweden)

    Despotis George J


    Full Text Available Abstract Background Ventricular assist devices(VAD implantation/removal is a complex surgical procedure with perioperative bleeding complications occurring in nearly half of the cases. Recombinant activated factor VII (rFVIIa has been used off-label to control severe hemorrhage in surgery and trauma. We report here our experience with rFVIIa as a rescue therapy to achieve hemostasis in patients undergoing orthotopic heart transplant (OHT and/or VAD implantation. Methods A retrospective review was conducted from Jan 03 to Aug 05 for patients who received rFVIIa for the management of intractable bleeding unresponsive to standard hemostatic blood component therapy. Blood loss and the quantity of blood products, prior to, and for at least 12 hours after, administration of rFVIIa were recorded. Results Mean patient age was 53, (38–64 yrs, mean dose of rFVIIa administered was 78.3 μg/kg (24–189 μg/kg in 1–3 doses. All patients received the drug either intraoperatively or within 6 hours of arrival in ICU. Mean transfusion requirements and blood loss were significantly reduced after rFVIIa administration (PRBC's; 16.9 ± 13.3 to 7.1 ± 6.9 units, FFP; 13.1 ± 8.2 to 4.1 ± 4.9 units, platelets; 4.0 ± 2.8 to 2.1 ± 2.2 units, p Conclusion In this review, there was a significant decrease in transfusion requirement and blood loss after rFVIIa administration. Although, 5/17 developed thromboembolic complications, these patients may have been at higher risk based on the multiple modality therapy used to manage intractable bleeding. Nevertheless, the exact role of rFVIIa with respect to development of thromboembolic complications cannot be clearly determined. Further investigation is needed to determine rFVIIa's safety and its effectiveness in improving postoperative morbidity and mortality.

  6. Evaluation of the Wider system, a new computer-assisted image-processing device for bacterial identification and susceptibility testing. (United States)

    Cantón, R; Pérez-Vázquez, M; Oliver, A; Sánchez Del Saz, B; Gutiérrez, M O; Martínez-Ferrer, M; Baquero, F


    The Wider system is a newly developed computer-assisted image-processing device for both bacterial identification and antimicrobial susceptibility testing. It has been adapted to be able to read and interpret commercial MicroScan panels. Two hundred forty-four fresh consecutive clinical isolates (138 isolates of the family Enterobacteriaceae, 25 nonfermentative gram-negative rods [NFGNRs], and 81 gram-positive cocci) were tested. In addition, 100 enterobacterial strains with known beta-lactam resistance mechanisms (22 strains with chromosomal AmpC beta-lactamase, 8 strains with chromosomal class A beta-lactamase, 21 broad-spectrum and IRT beta-lactamase-producing strains, 41 extended-spectrum beta-lactamase-producing strains, and 8 permeability mutants) were tested. API galleries and National Committee for Clinical Laboratory Standards (NCCLS) microdilution methods were used as reference methods. The Wider system correctly identified 97.5% of the clinical isolates at the species level. Overall essential agreement (+/-1 log(2) dilution for 3,719 organism-antimicrobial drug combinations) was 95.6% (isolates of the family Enterobacteriaceae, 96.6%; NFGNRs, 88.0%; gram-positive cocci, 95.6%). The lowest essential agreement was observed with Enterobacteriaceae versus imipenem (84.0%), NFGNR versus piperacillin (88.0%) and cefepime (88.0%), and gram-positive isolates versus penicillin (80.4%). The category error rate (NCCLS criteria) was 4.2% (2.0% very major errors, 0.6% major errors, and 1. 5% minor errors). Essential agreement and interpretive error rates for eight beta-lactam antibiotics against isolates of the family Enterobacteriaceae with known beta-lactam resistance mechanisms were 94.8 and 5.4%, respectively. Interestingly, the very major error rate was only 0.8%. Minor errors (3.6%) were mainly observed with amoxicillin-clavulanate and cefepime against extended-spectrum beta-lactamase-producing isolates. The Wider system is a new reliable tool which applies the

  7. Prediction of right ventricular failure after ventricular assist device implant: systematic review and meta-analysis of observational studies. (United States)

    Bellavia, Diego; Iacovoni, Attilio; Scardulla, Cesare; Moja, Lorenzo; Pilato, Michele; Kushwaha, Sudhir S; Senni, Michele; Clemenza, Francesco; Agnese, Valentina; Falletta, Calogero; Romano, Giuseppe; Maalouf, Joseph; Dandel, Michael


    Right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation is associated with increased morbidity and mortality, but the identification of LVAD candidates at risk for RVF remains challenging. We undertook a systematic review and meta-analysis of observational studies of risk factors associated with RVF after LVAD implant. Thirty-six studies published between 1 January 1995 and 30 April 2015, comprising 995 RVF patients out of a pooled final population of 4428 patients, were identified. Meta-analysed prevalence of post-LVAD RVF was 35%. A need for mechanical ventilation [odds ratio (OR) 2.99], or continuous renal replacement therapy (CRRT; OR 4.61, area under the curve 0.78, specificity 0.91) were the clinical variables with the highest effect size (ES) in predicting RVF. International normalized ratio [INR; standardized mean difference (SMD) 0.49] and N-terminal pro-brain natriuretic peptide (NT-proBNP) (SMD 0.52) were the biochemical markers that best discriminated between RVF and No-RVF populations, though NT-proBNP was highly heterogeneous. Right ventricular stroke work index (RVSWI) and central venous pressure (CVP) (SMD -0.58 and 0.47, respectively) were the haemodynamic measures with the highest ES in identifying patients at risk of post-LVAD RVF; CVP was particularly useful in risk stratifying patients undergoing continuous-flow LVAD implant (SMD 0.59, P implant moderate to severe right ventricular (RV) dysfunction, as assessed qualitatively (OR 2.82), or a greater RV/LV diameter ratio (SMD 0.51) were the standard echocardiographic measurements with the highest ES in comparing RVF with No-RVF patients. Longitudinal systolic strain of the RV free wall had the highest ES (SMD 0.73) but also the greatest heterogeneity (I(2) = 74%) and was thus only marginally significant (P = 0.05). Patients on ventilatory support or CRRT are at high risk for post-LVAD RVF, similarly to patients with slightly increased INR, high NT-proBNP or

  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


    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. (United States)

    Dicianno, Brad E; Morgan, Amy; Lieberman, Jenny; Rosen, Lauren


    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. 经皮心脏辅助装置的临床应用现状与进展%Clinical Application and Progression of Percutaneous Cardiac Assist Devices

    Institute of Scientific and Technical Information of China (English)



    近年来,经皮心脏辅助装置在心力衰竭、急性心肌梗死、心源性休克以及行经皮冠状动脉介入治疗的高危患者的治疗方面取得了显著的进展.经皮心脏辅助装置在提供患者血流动力学支持和心肌缺血保护方面的作用得到充分地证实.现就近年的临床应用现状和进展做简要的综述.%In recent years, percutaneous heart assist devices have been used in the treatment of heart failure, acute myocardial infarction, cardiogenic shock and patients undergoing high-risk percutaneous coronary intervention. Cardiovascular benefits of the devices including hemo-dynamic support and myocardial ischemic protection have been confirmed fully. This article provides an overview of recent progress made in the clinical application of percutaneous heart assist devices.

  11. The Application of Bileaflet Mechanical Heart Valves in the Polish Ventricular Assist Device: Physical and Numerical Study and First Clinical Usage. (United States)

    Malota, Zbigniew; Sadowski, Wojciech; Krzyskow, Marek; Stolarzewicz, Bogdan


    The Polish ventricular assist device (Polvad) has been used successfully in clinical contexts for many years. The device contains two single-disc valves, one at the inlet and one at the outlet connector of the pneumatic pump. Unfortunately, in recent years, a problem has occurred with the availability of single-disc valves. This article presents the possibility of using bileaflet mechanical heart valve prostheses in the Polvad to avoid a discontinuity in clinical use. The study is based on experimental and numerical simulations and comparison of the distribution of flow, pressure, and stress (wall, shear, and turbulent) inside the Polvad chamber and the inlet/outlet connectors fitted with Sorin Monodisc and Sorin Bicarbon Fitline valves. The type and orientation of the inlet valve affects valve performance and flow distribution inside the chamber. Near-wall flow is observed for single-disc valves. In the case of bileaflet valves, the main jet is directed more centrally, with lower shear stress but higher turbulent stress in comparison with single-disc valves. For clinical usage, a 45° orientation of the bileaflet inlet valve was chosen, as this achieves good washing of the inlet area near the membrane paste surface. The Polvad with bileaflet valves has now been used successfully in our clinic for over a year and will continue to be used until new assist devices for heart support are developed.

  12. Correlation of motor control in the supine position and assistive device used for ambulation in chronic incomplete spinal cord-injured persons. (United States)

    Tang, S F; Tuel, S M; McKay, W B; Dimitrijevic, M R


    Neurocontrol of movement after spinal cord injury (SCI) is often spared, but few studies have investigated the chronic incomplete SCI patient. Multichannel surface electromyography (SEMG) can describe characteristics of neurocontrol during a series of volitional and reflex events. The relationship of these neurocontrol characteristics to clinical function is incompletely described. This study, retrospectively, evaluated the relationship between neurocontrol patterns evoked by lower limb movement in the supine position and the assistive device used for ambulation in chronic, incomplete SCI persons. The records of 15 neurologically healthy (9 male, 6 female) and 36 incomplete SCI persons (27 male, 9 female) (C2-T10) were used. SEMG was recorded from both quadriceps, adductors, hamstrings, anterior tibialis and triceps surae muscles and displayed on a stripchart for analysis. SEMG patterns of activity recorded in the supine position during volitional, unilateral, multijoint (hip and knee flexion and extension) movement attempts were characterized, divided into seven groups and compared with the subjects' self-selected ambulation device (independent, cane, crutches, walker or nonambulatory). The neurocontrol patterns recorded in the supine position correlated well with the SCI subjects ambulatory assistive device. Marked decreases in motor unit output and/or loss of motor organization were found in the nonambulatory group. Coactivation of proximal muscles, poor timing of muscle activity and radiation of activity into contralateral muscles were also noted in subjects who required a walker or crutches. To a lesser degree, abnormal motor patterns were also noted in subjects who ambulated with a cane or independently.

  13. 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


    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.

  14. Management of pleural empyema with a vacuum-assisted closure device and reconstruction of open thoracic window in a patient with liver cirrhosis. (United States)

    Munguía-Canales, Daniel Alejandro; Vargas-Mendoza, Gary Kosai; Alvarez-Bestoff, Gustavo; Calderón-Abbo, Moisés Cutiel


    The patient is a 21-year-old female, diagnosed with cryptogenic cirrhosis at the age of 9. She presented with left post-pneumonic empyema that did not remit with conventional medical management and evolved with fistulization to the skin in the 7th intercostal space in the left subscapular region. We performed an open thoracic window procedure, and on the 6th day the patient was sent home with a portable vacuum-assisted closure device, with changes of the material every 4 days until the cavity was completed obliterated (92 days). Imaging tests showed full expansion of the lung, and chest wall reconstruction was performed with titanium rods. The high mortality of empyema in patients with liver disease requires both implementing and searching for new adjuvant therapies, like the use of vacuum-assisted closure systems and reconstruction with titanium rods. Controlled studies with a wide range of cases are needed for proper evaluation.

  15. 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;


    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...

  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 (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.


    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. Assistive devices for the children with cerebral palsy%辅助器具在小儿脑性瘫痪康复中的选用探讨

    Institute of Scientific and Technical Information of China (English)



    本文针对小儿脑性瘫痪(脑瘫)康复中辅助器具的作用和选用进行探讨,并介绍了60多种供个人使用和训练用的相关辅助器具。在小儿脑瘫的康复过程中需要应用辅助器具来改善脑瘫患儿的功能障碍、帮助建立正常的运动模式、防止畸形进一步加重和提高他们的生活自理能力。为此着重提出了小儿脑瘫肢体残疾辅助器具选用时要考虑的3个因素:即按照儿童运动发育规律、按照脑瘫儿功能障碍的身体部位、按照脑瘫儿的日常生活能力来选用。此外,有部分辅助器具将伴随脑瘫儿一生,成为他们回归社会的无障碍通道。%The effect and application of assistive devices for the children with cerebral palsy and about 60 kinds of assistive devices are introduced in this paper. The paper points out that assistive devices for the disabled are an access of the disabled to the society of normal persons and an important method applied in comprehensive rehabilitation process. Three ways to select assistive devices for the children with C.P. are suggested in the paper. The first way is to consider the basis of the rule of children' s activity to grow up. The second is the basis of the position of disabled part at the body. The third is the basis of ability of daily life.

  18. Continuous-flow left ventricular assist device support in patients with advanced heart failure: points of interest for the daily management. (United States)

    Felix, S E A; Martina, J R; Kirkels, J H; Klöpping, C; Nathoe, H; Sukkel, E; Hulstein, N; Ramjankhan, F Z; Doevendans, P A F M; Lahpor, J R; de Jonge, Nicholaas


    Today, continuous-flow left ventricular assist devices (cf-LVADs) are implanted more often in patients with end-stage heart failure. Because of greater durability they can be implanted for an extended period of time. As a result of increased numbers of patients on cf-LVAD support, healthcare professionals should be aware of the potential complications inherent to this therapy. Both bleeding and thrombosis may occur, and also complications related either to the device itself or to the ensuing altered haemodynamics, valvular pathology, and rhythm disturbances such as ventricular tachycardias and fibrillation. Accurate clinical evaluation, together with an electrocardiogram and, if necessary, combined with an echocardiogram, is obligatory in these situations. This review summarizes common complications complemented by a few clinical cases.

  19. Review of recent results using computational fluid dynamics simulations in patients receiving mechanical assist devices for end-stage heart failure. (United States)

    Farag, Mina Berty; Karmonik, Christof; Rengier, Fabian; Loebe, Matthias; Karck, Matthias; von Tengg-Kobligk, Hendrik; Ruhparwar, Arjang; Partovi, Sasan


    Many end-stage heart failure patients are not eligible to undergo heart transplantation due to organ shortage, and even those under consideration for transplantation might suffer long waiting periods. A better understanding of the hemodynamic impact of left ventricular assist devices (LVAD) on the cardiovascular system is therefore of great interest. Computational fluid dynamics (CFD) simulations give the opportunity to study the hemodynamics in this patient population using clinical imaging data such as computed tomographic angiography. This article reviews a recent study series involving patients with pulsatile and constant-flow LVAD devices in which CFD simulations were used to qualitatively and quantitatively assess blood flow dynamics in the thoracic aorta, demonstrating its potential to enhance the information available from medical imaging.

  20. 阅读辅助机器人取书装置设计%Design on a pickup device for assistive reading robot

    Institute of Scientific and Technical Information of China (English)

    徐兆红; 宋成利; 闫士举


    BACKGROUND: Assistive rehabilitation device can realize the maximum self-care and participation in society activity in the disabled.OBJECTIVE: To design a newtype pickup device by analyzing the research status of assistive read ng robots in home and abroad .M ETHODS : We designed a pick-up device to help the disabled obtain books from the shelves.RESULTS AND CONCLUSION: The simulation shows the pick-up book device is reliable and safe, effective and feasible based on the three-dimensional UG software.%背景:康复辅具是利用辅助技术将辅助器具产品配置于残障者,最大限度实现生活自理和参与社会活动.目的:分析了国内外阅读辅助机器人的研究现状,并对该领域的一些关键技术进行探讨,并设计出了一种新型取书装置.方法:依据阅读辅助机器人的发展特点和应用背景,设计一种阅读辅助机器人的取书装置,帮助肢体残疾者从书架上获取书籍.结果与结论:基于三维设计软件UG设计了阅读辅助机器人的取书装置.通过运动仿真,功能满足拟人化,能够完成取书的动作.仿真表明该装置可靠安全,有效可行.

  1. Three Dimensional Finite Element Analysis of Stress Distribution and Displacement of the Maxilla Following Surgically Assisted Rapid Maxillary Expansion with Tooth- and Bone-Borne Devices

    Directory of Open Access Journals (Sweden)

    Mohsen Dalband


    Full Text Available Objectives: The aim of this study was to investigate the displacement and stress distri- bution during surgically assisted rapid maxillary expansion under different surgical conditions with tooth- and bone-borne devices.Materials and Methods: Three-dimensional (3D finite element model of a maxilla was constructed and an expansion force of 100 N was applied to the left and right molars and premolars with tooth-borne devices and the left and right of mid-palatal sutures at the first molar level with bone-borne devices. Five CAD models were simulated as fol- lows and surgical procedures were used:  G1: control group (without surgery; G2: Le Fort I osteotomy; G3: Le Fort I osteotomy and para-median osteotomy; G4: Le Fort I osteotomy and pterygomaxillary separation; and G5: Le Fort I osteotomy, para-median osteotomy, and pterygomaxillary separation.Results: Maxillary displacement showed a gradual increase from group 1 to group 5 in all three planes of space, indicating that Le Fort I osteotomy combined with para-me- dian osteotomy and pterygomaxillary separation produced the greatest displacement of the maxilla with both bone- and tooth-borne devices. Surgical relief and bone-borne devices resulted in significantly reduced stress on anchored teeth.Conclusion: Combination of Le Fort I and para-median osteotomy with pterygomaxil-lary separation seems to be an effective procedure for increasing maxillary expansion, and excessive stress side effects are lowered around the anchored teeth with the use of bone-borne devices.

  2. Temporary left ventricular assist device through an axillary access is a promising approach to improve outcomes in refractory cardiogenic shock patients. (United States)

    Doersch, Karen M; Tong, Carl W; Gongora, Enrique; Konda, Subbareddy; Sareyyupoglu, Basar


    Cardiogenic shock (CS) causes significant morbidity and mortality and such patients can deteriorate rapidly. Temporary left ventricular assist devices (LVADs) are a promising approach to manage these patients. The following is a case series in which patients stabilized with a temporary LVAD for CS improvement were analyzed retrospectively. Between June 2011 and January 2014, 15 patients received temporary devices through an axillary approach (mean age: 53 ± 15, 93% male). Mean survival time was 317.8 ± 359.5 days (range: 6-936 days). During support there were no major bleeding events, infectious complications at the axillary access site, upper extremity edema, or emboli. The most of the patients recovered from CS (93%) were mobilized (67%) and were extubated (73%) while on temporary device support. Median times to extubation, intensive care unit discharge, and discontinuation of inotropic medications were: 1.63, 18, and 15 days, respectively. Four patients recovered to no device support and five received a long-term LVAD, all of whom remain alive. Therefore, implantation of a temporary LVAD through an axillary approach is a promising therapy for improving outcomes in patients needing mechanical circulatory support as a bridge to recovery or a definitive LVAD.

  3. Fluoroscopy assisted tracheal intubation in a case of anticipated difficult airway: Fail safe devices can also fail. (United States)

    Arulvelan, Appavoo; Soumya, Madhusudhan; Santhosh, Kannath


    Difficulty in airway management is the most important cause of major anesthesia-related morbidity and mortality. Unexpected difficulties may arise even with proper preanesthesia planning. Here, we report a case of anticipated difficult airway primarily planned for flexible fibreoptic bronchoscope assisted intubation, but due to unexpected failure of light source, fluoroscopy was used, and the airway was successfully secured.

  4. Knowledge from Research and Practice on the Barriers and Carriers to Successful Technology Transfer for Assistive Technology Devices (United States)

    Leahy, James A.; Lane, Joseph P.


    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…

  5. Device characterization and optimization of small molecule organic solar cells assisted by modelling simulation of the current-voltage characteristics. (United States)

    Zuo, Yi; Wan, Xiangjian; Long, Guankui; Kan, Bin; Ni, Wang; Zhang, Hongtao; Chen, Yongsheng


    In order to understand the photovoltaic performance differences between the recently reported DR3TBTT-HD and DR3TBDT2T based solar cells, a modified two-diode model with Hecht equation was built to simulate the corresponding current-voltage characteristics. The simulation results reveal that the poor device performance of the DR3TBDTT-HD based device mainly originated from its insufficient charge transport ability, where an average current of 5.79 mA cm(-2) was lost through this pathway at the maximum power point for the DR3TBDTT-HD device, nearly three times as large as that of the DR3TBDT2T based device under the same device fabrication conditions. The morphology studies support these simulation results, in which both Raman and 2D-GIXD data reveal that DR3TBTT-HD based blend films exhibit lower crystallinity. Spin coating at low temperature was used to increase the crystallinity of DR3TBDTT-HD based blend films, and the average current loss through insufficient charge transport at maximum power point was suppressed to 2.08 mA cm(-2). As a result, the average experimental power conversion efficiency of DR3TBDTT-HD based solar cells increased by over 40%.

  6. Home-based Computer Assisted Arm Rehabilitation (hCAAR) robotic device for upper limb exercise after stroke: results of a feasibility study in home setting. (United States)

    Sivan, Manoj; Gallagher, Justin; Makower, Sophie; Keeling, David; Bhakta, Bipin; O'Connor, Rory J; Levesley, Martin


    Home-based robotic technologies may offer the possibility of self-directed upper limb exercise after stroke as a means of increasing the intensity of rehabilitation treatment. The current literature has a paucity of robotic devices that have been tested in a home environment. The aim of this research project was to evaluate a robotic device Home-based Computer Assisted Arm Rehabilitation (hCAAR) that can be used independently at home by stroke survivors with upper limb weakness. hCAAR device comprises of a joystick handle moved by the weak upper limb to perform tasks on the computer screen. The device provides assistance to the movements depending on users ability. Nineteen participants (stroke survivors with upper limb weakness) were recruited. Outcome measures performed at baseline (A0), at end of 8-weeks of hCAAR use (A1) and 1 month after end of hCAAR use (A2) were: Optotrak kinematic variables, Fugl Meyer Upper Extremity motor subscale (FM-UE), Action Research Arm Test (ARAT), Medical Research Council (MRC) and Modified Ashworth Scale (MAS), Chedoke Arm and Hand Activity Inventory (CAHAI) and ABILHAND. Two participants were unable to use hCAAR: one due to severe paresis and the other due to personal problems. The remaining 17 participants were able to use the device independently in their home setting. No serious adverse events were reported. The median usage time was 433 minutes (IQR 250 - 791 min). A statistically significant improvement was observed in the kinematic and clinical outcomes at A1. The median gain in the scores at A1 were by: movement time 19%, path length 15% and jerk 19%, FM-UE 1 point, total MAS 1.5 point, total MRC 2 points, ARAT 3 points, CAHAI 5.5 points and ABILHAND 3 points. Three participants showed clinically significant improvement in all the clinical outcomes. The hCAAR feasibility study is the first clinical study of its kind reported in the current literature; in this study, 17 participants used the robotic device independently

  7. Remote Surveillance System of Artificial Ventricular Assist Device%人工心室辅助装置远程监控系统

    Institute of Scientific and Technical Information of China (English)

    李晶晶; 杨明; 吕雪烽


    人工心室辅助装置作为高端医疗设备,需要保证其使用的便携性和可靠性.围绕这一目标,研究基于嵌入式CompactRIO平台和以太网技术,构建心室辅助装置的远程监控系统.该系统能够监测并控制心室辅助装置工作的状态和辅助流量,支持远端WEB查询功能,并结合试验室心室辅助装置驱动模块进行了测试.%Performances of reliability and portability are important for artificial ventricular assist devices.This paper presents a remote surveillance system that can observe the condition of the patients and the driving condition of artificial heart online.The system is mainly based on the embedded Compact RIO platform and Ethernet technology.Combined with the driver module of the assist device, this remote system has been tested.

  8. 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


    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.

  9. Off-pump exchange of short-term percutaneous ventricular assist device (VAD) to long-term implantable VAD in severe coagulopathy and multi-organ failure. (United States)

    Busch, Jonas; Wojciechowski, Zbiguiew; Torre-Amione, Guillermo; Loebe, Matthias


    Ventricular support in patients with end-stage heart failure can be achieved using intracorporeal left ventricular assist device (LVAD) or percutaneous ventricular assist device (pVAD) systems. Multiple efforts have been made to minimize procedure-associated complications. We present a case report of an off-pump insertion of a MicroMed DeBakey VAD after Tandem Heart support using a previous sternotomy incision. A 47-year-old woman with end-stage heart failure after coronary artery bypass graft revascularization was admitted for pharmacologic treatment. She developed multi-organ failure and a severe coagulopathy with thromboembolic complications. Heparin-induced thrombocytopenia (HIT) was suspected. A percutaneous Tandem Heart was placed, the patient's condition stabilized, and finally a MicroMed DeBakey Child VAD was implanted off-pump, re-opening a previous sternotomy incision. To avoid the need for heparinization in the light of HIT and severe coagulopathy, the LVAD implantation was performed under Tandem Heart support without cardiopulmonary bypass. The patient has been anti-coagulated with angiomax ever since. Critically ill patients with end-stage heart disease, multi-organ failure, severe coagulopathy and a previous median sternotomy can be bridged from a Tandem Heart to MicroMed DeBakey VAD without cardiopulmonary bypass using the previous incision, provided there are few adhesions and stable hemodynamic conditions.

  10. Development Status of Ventricular Assist Devices in Children%儿童心室辅助装置发展现状

    Institute of Scientific and Technical Information of China (English)

    孟凡; 杨明; 胡仁杰


    越来越多的儿童心衰患者需要采用心室辅助装置进行移植过渡与心功能恢复治疗,而目前儿童用辅助装置的发展严重落后于成人辅助装置,临床选择非常有限。本文介绍了目前临床中使用的几种儿童用辅助装置以及国内外在该方面的研究进展。由于不同年龄儿童的生理参数差异以及儿童异于成人的某些特殊辅助需求,儿童心室辅助装置需要向多规格、小体积、搏动性、智能化等方向发展。%There has been an increased demand for using ventricular assist devices (VAD) as a bridge to transplant and myocardial recovery in children with end-stage heart failure. The development of pediatric VADs, however, has lagged behind the development of adult ventricular assist devices, which makes the clinical choices of VADs in pediatric care very limited. The purpose of this review is to describe several pediatric VADs in the clinical settings as well as to examine the research progress of VADs both at home and abroad. Because of the different physiological parameters of children of different ages groups, also because of the difference between children and adults, especially of the variances in the the demands of the pumping assistance, pediatric VADs need to developed into multi-modes characterized by small volumes, with pulsatile and intelligent action that emulates the heart.

  11. Identification and Management of Pump Thrombus in the HeartWare Left Ventricular Assist Device System: A Novel Approach Using Log File Analysis. (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


    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 < 0.0001). Medical therapy was successful in 77.7% of the algorithm development cohort and 81.3% of the validation cohort when the rate of power increase and percent of expected power values were <1.25% and 200%, respectively. Log 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.

  12. 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: [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)


    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%.

  13. The second device for measuring of the thickness of the falling condensate in the gravity assisted heat pipe (United States)

    Lenhard, Richard; Malcho, Milan


    This article describes a device for measuring the thickness of a falling condensate that allowed comparison of calculations with the measurements. This article is a basic methodology for measuring the thickness of the falling condensate in gravitational heat pipes, with using the optical triangulation method, and the evaluation of risks associated with this method.

  14. Myocardial changes in patients with end-stage heart failure during continuous flow left ventricular assist device support

    NARCIS (Netherlands)

    Lok, S.I.|info:eu-repo/dai/nl/370140508


    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 cons

  15. Validation of the Greek version of the device subscale of the Quebec User Evaluation of Satisfaction with Assistive Technology 2.0 (QUEST 2.0). (United States)

    Koumpouros, Yiannis; Karavasili, Alexandra; Papageorgiou, Effie; Siavelis, Panagiotis


    The purpose of the study was to evaluate the device subscale of the QUEST 2.0 instrument and provide evidence for the validity and reliability of the Greek version. To this end, a cross-cultural adaptation was performed. Field test studies were conducted to validate the appropriateness of the final outcome. Data were drawn from a study of 115 subjects who had been administered the GR-QUEST questionnaire. Ratings related to the different items were statistically analyzed. The exploratory factor analysis with varimax rotation conducted revealed a three factors structure of the device subscale in contrast with previous studies. Our "Safe Use" subscale contains the items adjustments, safety and effectiveness of the original instrument, the "Fit to Use" subscale contains the dimensions, weight and ease of use items, and the "Endurance" subscale contains the items durability and comfort of the original questionnaire. Reliability measures (ICC=0.949, Pearson´s correlation=0.903, Cronbach´s α=0.754) yielded high values. Test-retest outcome showed great stability. Based on the results, the GR-QUEST can be considered as a valid and reliable instrument and thus it can be used to measure the satisfaction of patients with assistive devices, while it is applicable to the Greek population. Further assessment of the services subscale is needed.

  16. Identification of differentially expressed transcripts and pathways in blood one week and six months following implant of left ventricular assist devices.

    Directory of Open Access Journals (Sweden)

    Adam Mitchell

    Full Text Available INTRODUCTION: Continuous-flow left ventricular assist devices (LVADs are an established therapy for patients with end-stage heart failure. The short- and long-term impact of these devices on peripheral blood gene expression has not been characterized, and may provide insight into the molecular pathways mediated in response to left ventricular remodeling and an improvement in overall systemic circulation. We performed RNA sequencing to identify genes and pathways influenced by these devices. METHODS: RNA was extracted from blood of 9 heart failure patients (8 male prior to LVAD implantation, and at 7 and 180 days postoperatively. Libraries were sequenced on an Illumina HiSeq2000 and sequences mapped to the human Ensembl GRCh37.67 genome assembly. RESULTS: A specific set of genes involved in regulating cellular immune response, antigen presentation, and T cell activation and survival were down-regulated 7 days after LVAD placement. 6 months following LVAD placement, the expression levels of these genes were significantly increased; yet importantly, remained significantly lower than age and sex-matched samples from healthy controls. CONCLUSIONS: In summary, this genomic analysis identified a significant decrease in the expression of genes that promote a healthy immune response in patients with heart failure that was partially restored 6 months following LVAD implant.

  17. Nano-gold assisted highly conducting and biocompatible bacterial cellulose-PEDOT:PSS films for biology-device interface applications. (United States)

    Khan, Shaukat; Ul-Islam, Mazhar; Ullah, Muhammad Wajid; Israr, Muhammad; Jang, Jae Hyun; Park, Joong Kon


    This study reports the fabrication of highly conducting and biocompatible bacterial cellulose (BC)-gold nanoparticles (AuNPs)-poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) (BC-AuNPs-PEDOT:PSS) composites for biology-device interface applications. The composites were fabricated using ex situ incorporation of AuNPs and PEDOT:PSS into the BC matrix. Structural characterization, using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and x-ray diffraction (XRD) analysis, confirmed the uniform nature of the synthesized BC-AuNPs and BC-AuNPs-PEDOT:PSS composites. Four-point probe analysis indicated that the BC-AuNPs and BC-AuNPs-PEDOT:PSS films had high electrical conductivity. The composites were also tested for biocompatibility with animal osteoblasts (MC3T3-E1). The composite films supported adhesion, growth, and proliferation of MC3T3-E1 cells, indicating that they are biocompatible and non-cytotoxic. AuNPs and PEDOT:PSS, imparted a voltage response, while BC imparted biocompatibility and bio-adhesion to the nanocomposites. Therefore, our BC-AuNPs-PEDOT:PSS composites are candidate materials for biology-device interfaces to produce implantable devices in regenerative medicine. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Fabrication of nanowires of Al-doped ZnO using nanoparticle assisted pulsed laser deposition (NAPLD) for device applications

    Energy Technology Data Exchange (ETDEWEB)

    Thanka Rajan, S. [ECMS Division, CSIR – Central Electrochemical Research Institute, Karaikudi 630 006 (India); Subramanian, B., E-mail: [ECMS Division, CSIR – Central Electrochemical Research Institute, Karaikudi 630 006 (India); Nanda Kumar, A.K.; Jayachandran, M. [ECMS Division, CSIR – Central Electrochemical Research Institute, Karaikudi 630 006 (India); Ramachandra Rao, M.S. [Department of Physics, Indian Institute of Technology Madras, Chennai 600 036 (India)


    Graphical abstract: -- Highlights: • Novel technique of NP assisted PLD was employed to obtain Al doped ZnO. • AZO nano wires with aspect ratios exceeding 20 were obtained at 500 sccm Ar gas pressure. • AZO films belong to the most stable wurtzite type. • Films show near band edge emission and defect related emission. -- Abstract: Aluminium doped zinc oxide (AZO) nanostructures have been successfully synthesized on sapphire substrates by using nanoparticle assisted pulsed laser deposition (NAPLD) in Ar atmosphere without using any catalyst. The growth of the AZO nanowires has been investigated by varying the argon flow rates. The coatings have been characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Atomic force microscopy (AFM), Diffuse Reflectance Spectroscopy (DRS), Laser Raman spectroscopy and Photoluminescence spectroscopy. The results of XRD indicate that the deposited films are crystalline ZnO with hexagonal wurtzite structure with (0 0 2) preferred orientation. FESEM images also clearly reveal the hexagonal structure and the formation of nanowires with aspect ratios between 15 and 20. The surface roughness value of 9.19 nm was observed from AFM analysis. The optical properties of the sample showed that under excitation with λ = 325 nm, an emission band was observed in UV and visible region. The characteristic Raman peaks were detected at 328, 380, 420, 430 cm{sup −1}.

  19. 液力助捞器的研制与应用%Development and Application of Hydraulic Fishing-assisted Device

    Institute of Scientific and Technical Information of China (English)

    马艳洁; 赵丹星; 王宏万; 梁秀红; 孙金峰; 丁志聪


    When the hollow water injection string is used, the core of water flow regulator sometimes fails to be fished smoothly within the scope of the rated operating pull of steel wire rope. Considering the problem, the hydraulic fishing-assisted device was developed. The device consists of fishing part, supporting part and sealing part. The hydraulic force was adopted to increase the fishing force effectively, raising the fishing force to 2 000 N/MPa and thus reducing the fishing truck load. When the water regulator core cannot be fished, the hydraulic fishing-assisted device can use the hydraulic force to snip the safety pin and get the core out of the well safe and sound, thus effectively avoiding the appearance of the logging steel wire breaking. The device has finished fishing 189 times in Shengli Oilfield with a 97.4% success rate.%针对空心注水管柱有时在钢丝绳额定工作拉力范围内无法将配水器心子顺利捞出的问题,研制了液力助捞器。液力助捞器由打捞部分、支撑部分和密封部分组成,它采用液压力有效增加打捞动力,将打捞力提高至2 000 N/MPa,减轻了打捞车载荷。当配水器心子打捞不动时,液力助捞器可利用液压力剪断安全销,从井内安全起出,有效避免了录井钢丝绳断裂事故的发生。采用液力助捞器在胜利油田共计打捞心子189次,打捞成功率97.4%,液力助捞器起出率100%。

  20. Ultra-thin titanium nanolayers for plasmon-assisted enhancement of bioluminescence of chloroplast in biological light emitting devices (United States)

    Hsun Su, Yen; Hsu, Chia-Yun; Chang, Chung-Chien; Tu, Sheng-Lung; Shen, Yun-Hwei


    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.

  1. 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)


    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.

  2. 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. (United States)

    Kaufmann, Friedrich; Krabatsch, Thomas


    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.

  3. To move as a human. Comment on "The embodiment of assistive devices-from wheelchair to exoskeleton" by M. Pazzaglia and M. Molinari (United States)

    Papadimitriou, Christina


    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.

  4. Biventricular failure with low pulmonary vascular resistance was managed by left ventricular assist device alone without right-sided mechanical support. (United States)

    Imamura, Teruhiko; Kinugawa, Koichiro; Nitta, Daisuke; Hatano, Masaru; Kinoshita, Osamu; Nawata, Kan; Ono, Minoru


    How to manage preoperative right ventricular dysfunction (RVD) in heart failure patients without cardiogenic shock remains as a matter to be debated because implantable biventricular assist device treatment has not been established thus far. We here presented a patient with significant RVD indicated by low RV stroke work index (0.3 g/m) and RV dilatation as well as low pulmonary vascular resistance (PVR, 0.8 Wood Unit), who was managed by the introduction of pimobendan and sildenafil after the implantation of DuraHeart and tricuspid annuloplasty without right VAD, although his New York Heart Association symptom remained class III. Preoperative low PVR may be a key for successful LVAD treatment alone without right VAD in patients with INTERMACS profile 3 suffering RVD.

  5. Left Ventricular Assist Device and Resident Cardiac Stem Cells in Heart Failure: Human Heart’s Potential Matter

    Directory of Open Access Journals (Sweden)

    Mariangela Peruzzi


    Full Text Available Heart disease is the leading cause of mortality in Western countries, accounting for 17.3 million deaths per year. The impact of cardiovascular diseases is influenced by the ability to treat and assist patients surviving acute myocardial infarction (AMI, which has resulted in a nearly epidemic of chronic heart failure (HF, with roughly 5.8 million people with this diagnosis and about 500,000 new cases every year in the U.S.A. Irrespective of the etiology and despite the fact that recent advances in medical and surgical treatments of HF have led to better treatments, 50% of patients die within a month after AMI, and 50% of those with severe HF die within a year. From a pathophysiologic point of view the hemodynamic overload generated by AMI imposes mechanical and neurohormonal challenges on cardiac walls, initially triggering compensatory left ventricular hypertrophy, but eventually activating complex biological responses evolving into maladaptive remodeling, untreatable with conventional therapy.

  6. Ionic-liquid-assisted synthesis of nanostructured and carbon-coated Li3V2(PO4)3 for high-power electrochemical storage devices. (United States)

    Zhang, Xiaofei; Böckenfeld, Nils; Berkemeier, Frank; Balducci, Andrea


    Carbon-coated Li3V2(PO4)3 (LVP) displaying nanostructured morphology can be easily prepared by using ionic-liquid-assisted sol-gel synthesis. The selection of highly viscous and thermally stable ionic liquids might promote the formation of nanostructures during the sol-gel synthesis. The presence of these structures shortens the diffusion paths and enlarges the contact area between the active material and the electrolyte; this leads to a significant improvement in lithium-ion diffusion. At the same time, the use of ionic liquids has a positive influence on the coating of the LVP particles, which improves the electronic conductivity of this material; this leads to enhanced charge-transfer properties. At a high current density of 40 C, the LVP/N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide material delivered a reversible capacity of approximately 100 mA h g(-1), and approximately 99 % of the initial capacity value was retained even after 100 cycles at 50 C. The excellent high rate and cycling stability performance make Li3V2(PO4)3 prepared by ionic-liquid-assisted sol-gel synthesis a very promising cathode material for high-power electrochemical storage devices.

  7. Captured Macro-embolus of Fractured Atheromatous Plaque by the Embolic Protection Device during Carotid Stent Assisted Angioplasty. (United States)

    Kim, Mun Chul; Bennett, Shelby; Farb, Richard; Croul, Sydney; Lee, Seon-Kyu


    The authors present a case in which macro-embolus from the ruptured atheromatous plaque developed during carotid artery stenting (CAS). A 63-year-old man who had suffered a left middle cerebral artery territory infarction had significant proximal left internal carotid artery stenosis required CAS procedure. Immediate after stent deployment, the patient showed abrupt neurological deterioration with 12 × 3 mm sized macro-embolus which was caught by the embolus protection device (EPD). Retrieval of the macro-embolus was performed safely and the patient recovered to pre-procedure status. Macro-embolus can be resulted during the CAS. The EPD can capture the macro-embolus and safe removal is technically feasible.

  8. Acute tamponade of the left paracorporeal pump house due to membrane defect in a patient with a Berlin Heart EXCOR biventricular assist device. (United States)

    Völz, Sebastian; Holmberg, Michael; Redfors, Bengt; Dellgren, Göran


    We report a case of acute tamponade of the left paracorporeal pump house in a patient supported by a Berlin Heart EXCOR biventricular assist device (BiVAD) caused by mechanical defect in the membrane of the arterial chamber. A 36-year old male was admitted for composite graft surgery due to a large aortic regurgitation and consecutive heart failure, decompensated postoperatively and was rescued by with an extracorporeal membrane oxygenation (ECMO) device. He was accepted for heart transplantation, and a BiVAD (Berlin Heart EXCOR) was implanted as bridge-to-transplantation. Two months after discharge, he experienced dyspnoea and received error signals from his BiVAD. Relatives released him from his BiVAD companion driver, connected him to the hand pump and transported him to our institution. On arrival, he was in cardiogenic shock and was stabilized by ECMO. Inspection of the arterial chamber revealed a wear hole and delamination of the diaphragm, which had led to a tamponade by air insufflation into the three-layer membrane. New BiVAD paracorporeal pumps were connected, and the patient was subsequently successfully transplanted. The case depicts the difficulty of diagnosis in this specific patient setting. Despite transparent design of the BiVAD chambers, the development of a chamber tamponade remained undetected until explantation of the system.

  9. Provision and financing of assistive technology devices in Germany: a bureaucratic odyssey? The case of amyotrophic lateral sclerosis and Duchenne muscular dystrophy. (United States)

    Henschke, Cornelia


    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.

  10. Topical Polymyxin-Trimethoprim Prophylaxis May Decrease the Incidence of Driveline Infections in Patients With Continuous-Flow Left Ventricular Assist Devices. (United States)

    Durand, Marlene L; Ennis, Stephanie C; Baker, Joshua N; Camuso, Janice M; McEachern, Kathleen M; Kotton, Camille N; Lewis, Gregory D; Garcia, Jose P; MacGillivray, Thomas E


    This retrospective cohort study evaluated the effect of topical polymyxin-trimethoprim (poly) prophylaxis on the incidence of driveline infections (DLIs) in patients with continuous-flow left ventricular assist devices. All 84 cases implanted 2005-2014 with device support ≥30 days were reviewed; support ranged 1 m-5.2 yrs. Beginning 2008, poly was applied to the exit site with dressing changes. Sixty-five patients received poly (poly group) for duration of follow-up, 19 did not (no-poly); group baseline characteristics were similar. No patient developed side effects from poly. Nineteen DLIs (10 in no-poly) occurred; not using poly was a risk factor. 89% of poly group DLIs were superficial, 4 were culture-negative. DLI-related bacteremia occurred in 11% of no-poly group and 0% of poly group. Compared with no-poly, poly group demonstrated improved freedom from DLI by Kaplan-Meier analysis (P 1 yr (38%) were similar. These findings, which should be confirmed with larger comparative studies, suggest that topical polymyxin-trimethoprim prophylaxis may be effective in preventing DLIs.

  11. Near-infrared absorptance enhancement and device application of nanostructured black silicon fabricated by metal-assist chemical etching (United States)

    Huang, Lieyun; Zhong, Hao; Liao, Naiman; Long, Fei; Guo, Guohui; Li, Wei


    We use metal-assist chemical etching (MCE) method to fabricate nanostructured black silicon on the surface of C-Si. In our MCE process, a chemical reduction reaction of silver cation (Ag+) will happen on the surface of silicon substrate, and at the same time the silicon atoms around Ag particles are oxidized and dissolved, generating nanopores and finally forming a layer called black silicon on the top of the substrates. The nanopores have diameter and depth of about 400 nm and 2 μm, respectively. Furthermore, these modified surfaces show higher light absorptance in near-infrared range (800 to 2500 nm) compared to that of C-Si with polished surfaces, and the maximum light absorptance increases significantly up to 95% in the wavelength region of 400 to 2500 nm. The Si-PIN photoelectronic detector based on this type of black silicon, in which the black silicon layer is directly set as the photosensitive surface, has a substantial increase in responsivity with about 80 nm red shift of peak responsivity, particularly at near-infrared wavelengths, rising to 0.57 A/W at 1060 nm and 0.37 A/W at 1100 nm, respectively. Our recent novel results clearly indicate that nanostructured black silicon made by MCE has a potential application in near-infrared photoelectronic detectors.

  12. 21 CFR 884.6150 - Assisted reproduction micromanipulators and microinjectors. (United States)


    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6150 Assisted reproduction micromanipulators and microinjectors. (a) Identification... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction micromanipulators...

  13. 21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments. (United States)


    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a) Identification... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction micropipette...

  14. Darcy permeability of hollow fiber membrane bundles made from Membrana® Polymethylpentene (PMP) fibers used in respiratory assist devices (United States)

    Madhani, Shalv. P.; D’Aloiso, Brandon. D.; Frankowski, Brian.; Federspiel, William. J.


    Hollow fiber membranes (HFMs) are used in blood oxygenators for cardiopulmonary bypass or in next generation artificial lungs. Flow analyses of these devices is typically done using computational fluid dynamics (CFD) modeling HFM bundles as porous media, using a Darcy permeability coefficient estimated from the Blake – Kozeny (BK) equation to account for viscous drag from fibers. We recently published how well this approach can predict Darcy permeability for fiber bundles made from polypropylene HFMs, showing the prediction can be significantly improved using an experimentally derived correlation between the BK constant (A) and bundle porosity (ε). In this study, we assessed how well our correlation for A worked for predicting the Darcy permeability of fiber bundles made from Membrana® polymethylpentene (PMP) HFMs, which are increasingly being used clinically. Swatches in the porosity range of 0.4 to 0.8 were assessed in which sheets of fiber were stacked in parallel, perpendicular and angled configurations. Our previously published correlation predicted Darcy within ±8%. A new correlation based on current and past measured permeability was determined: A=497ε-103; using this correlation measured Darcy permeability was within ±6%. This correlation varied from 8% to −3.5% of our prior correlation over the tested porosity range. PMID:26809086

  15. Darcy Permeability of Hollow Fiber Membrane Bundles Made from Membrana Polymethylpentene Fibers Used in Respiratory Assist Devices. (United States)

    Madhani, Shalv P; D'Aloiso, Brandon D; Frankowski, Brian; Federspiel, William J


    Hollow fiber membranes (HFMs) are used in blood oxygenators for cardiopulmonary bypass or in next generation artificial lungs. Flow analyses of these devices is typically done using computational fluid dynamics (CFD) modeling HFM bundles as porous media, using a Darcy permeability coefficient estimated from the Blake-Kozeny (BK) equation to account for viscous drag from fibers. We recently published how well this approach can predict Darcy permeability for fiber bundles made from polypropylene HFMs, showing the prediction can be significantly improved using an experimentally derived correlation between the BK constant (A) and bundle porosity (ε). In this study, we assessed how well our correlation for A worked for predicting the Darcy permeability of fiber bundles made from Membrana polymethylpentene (PMP) HFMs, which are increasingly being used clinically. Swatches in the porosity range of 0.4 to 0.8 were assessed in which sheets of fiber were stacked in parallel, perpendicular, and angled configurations. Our previously published correlation predicted Darcy within ±8%. A new correlation based on current and past measured permeability was determined: A = 497ε - 103; using this correlation measured Darcy permeability was within ±6%. This correlation varied from 8% to -3.5% of our prior correlation over the tested porosity range.

  16. A remote monitoring system for patients with implantable ventricular assist devices with a personal handy phone system. (United States)

    Okamoto, E; Shimanaka, M; Suzuki, S; Baba, K; Mitamura, Y


    The usefulness of a remote monitoring system that uses a personal handy phone for artificial heart implanted patients was investigated. The type of handy phone used in this study was a personal handy phone system (PHS), which is a system developed in Japan that uses the NTT (Nippon Telephone and Telegraph, Inc.) telephone network service. The PHS has several advantages: high-speed data transmission, low power output, little electromagnetic interference with medical devices, and easy locating of patients. In our system, patients have a mobile computer (Toshiba, Libretto 50, Kawasaki, Japan) for data transmission control between an implanted controller and a host computer (NEC, PC-9821V16) in the hospital. Information on the motor rotational angle (8 bits) and motor current (8 bits) of the implanted motor driven heart is fed into the mobile computer from the implanted controller (Hitachi, H8/532, Yokohama, Japan) according to 32-bit command codes from the host computer. Motor current and motor rotational angle data from inside the body are framed together by a control code (frame number and parity) for data error checking and correcting at the receiving site, and the data are sent through the PHS connection to the mobile computer. The host computer calculates pump outflow and arterial pressure from the motor rotational angle and motor current values and displays the data in real-time waveforms. The results of this study showed that accurate data on motor rotational angle and current could be transmitted from the subjects while they were walking or driving a car to the host computer at a data transmission rate of 9600 bps. This system is useful for remote monitoring of patients with an implanted artificial heart.

  17. Cardiac Health Risk Stratification System (CHRiSS: a Bayesian-based decision support system for left ventricular assist device (LVAD therapy.

    Directory of Open Access Journals (Sweden)

    Natasha A Loghmanpour

    Full Text Available This study investigated the use of Bayesian Networks (BNs for left ventricular assist device (LVAD therapy; a treatment for end-stage heart failure that has been steadily growing in popularity over the past decade. Despite this growth, the number of LVAD implants performed annually remains a small fraction of the estimated population of patients who might benefit from this treatment. We believe that this demonstrates a need for an accurate stratification tool that can help identify LVAD candidates at the most appropriate point in the course of their disease. We derived BNs to predict mortality at five endpoints utilizing the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS database: containing over 12,000 total enrolled patients from 153 hospital sites, collected since 2006 to the present day, and consisting of approximately 230 pre-implant clinical variables. Synthetic minority oversampling technique (SMOTE was employed to address the uneven proportion of patients with negative outcomes and to improve the performance of the models. The resulting accuracy and area under the ROC curve (% for predicted mortality were 30 day: 94.9 and 92.5; 90 day: 84.2 and 73.9; 6 month: 78.2 and 70.6; 1 year: 73.1 and 70.6; and 2 years: 71.4 and 70.8. To foster the translation of these models to clinical practice, they have been incorporated into a web-based application, the Cardiac Health Risk Stratification System (CHRiSS. As clinical experience with LVAD therapy continues to grow, and additional data is collected, we aim to continually update these BN models to improve their accuracy and maintain their relevance. Ongoing work also aims to extend the BN models to predict the risk of adverse events post-LVAD implant as additional factors for consideration in decision making.

  18. Benefits of ultra-fast-track anesthesia in left ventricular assist device implantation: a retrospective, propensity score matched cohort study of a four-year single center experience. (United States)

    Zayat, Rashad; Menon, Ares K; Goetzenich, Andreas; Schaelte, Gereon; Autschbach, Ruediger; Stoppe, Christian; Simon, Tim-Philipp; Tewarie, Lachmandath; Moza, Ajay


    The use of left ventricular assist devices (LVADs) has gained significant importance for treatment of end-stage heart failure. Fast-track procedures are well established in cardiac surgery, whereas knowledge of their benefits after LVAD implantation is sparse. We hypothesized that ultra-fast-track anesthesia (UFTA) with in-theater extubation or at a maximum of 4 h. after surgery is feasible in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level 3 and 4 patients and might prevent postoperative complications. From March, 2010 to March, 2012, 53 LVADs (50 Heart Mate II and 3 Heart Ware) were implanted in patients in our department. UFTA was successfully performed (LVAD ultra ) in 13 patients. After propensity score matching, we compared the LVAD ultra group with a matched group (LVAD match ) receiving conventional anesthesia management. Patients in the LVAD ultra group had significantly lower incidences of pneumonia (p = 0.031), delirium (p = 0.031) and right ventricular failure (RVF) (p = 0.031). They showed a significantly higher cardiac index in the first 12 h. (p = 0.017); a significantly lower central venous pressure during the first 24 h. postoperatively (p = 0.005) and a significantly shorter intensive care unit (ICU) stay (p = 0.016). Kaplan-Meier analysis after four years of follow-up showed no significant difference in survival. In this pilot study, we demonstrated the feasibility of ultra-fast-track anesthesia in LVAD implantation in selected patients with INTERMACS level 3-4. Patients had a lower incidence of postoperative complications, better hemodynamic performance, shorter length of ICU stay and lower incidence of RVF after UFTA. Prospective randomized investigations should examine the preservation of right ventricular function in larger numbers and identify appropriate selection criteria.

  19. 油麦兼用型气送式集排器供种装置设计与试验%Design and experiment of seed feeding device in air-assisted centralized metering device for rapeseed and wheat

    Institute of Scientific and Technical Information of China (English)

    雷小龙; 廖宜涛; 李兆东; 曹秀英; 李姗姗; 韦跃培; 廖庆喜


    Wheat and rapeseed are the major grain and oil crop in China and their sowing dates are closer. Seed feeding device is the core component of air-assisted centralized metering device which is capable of handling a wide range of seeds with different sizes and shapes. In order to improve the versatility and use efficiency of air-assisted centralized metering device and adjust the feeding rate accurately, the seed feeding device for rapeseed and wheat with staggered arrangement shape hole and combined conical-hole unit was designed. The problems of pulsing phenomenon due to outer grooved wheel metering device of the centralized pneumatic planter and high damage rate of mechanical metering device for rapeseed needed to be solved, and the structure of staggered arrangement shape hole could keep seeding consciously and uniformly. The seed feeding operation included seed filling, carrying and feeding process. The main structural parameters of shape hole and conical-hole unit were determined in this research. These included length, width, depth and cone angle of shape hole which were 8.0 mm, 5.0 mm, 4.0 mm and 14°, respectively. The diameter and number of shape holes in each conical-hole unit were 80 mm and 60, respectively. Mechanical models were established to estimate the seed filling and feeding process. It demonstrated that seed filling and throwing performance were better under the inclined angle of 13.75°-21.20°. Bench experiments were carried out in the seed metering laboratory of Huazhong Agricultural University in 2015 by using Huayouza 62 and Zhengmai 9023 as materials. The experimental factors were inclined angle (0°-30°) with 4 levels and rotational speed (10-60 r/min) with 6 levels in single-factor test. Two-factor full factorial test was designed with number of conical-hole unit (1-6) and rotational speed. The objective values were seed feeding rate, coefficient variation of seed feeding rate and damage rate. The results showed that: 1) The conical shape

  20. Development of a home-made extraction device for vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with lighter than water organic solvents. (United States)

    Yang, Zhong-Hua; Wang, Peng; Zhao, Wen-ting; Zhou, Zhi-Qiang; Liu, Dong-Hui


    We have developed a novel vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction using the low density solvent for the determination of eight organophosphorus pesticides (OPPs) in water samples. The key point of this method is the application of a special home-made extraction device. The influence parameters relevant to this method were systemically investigated and the optimum conditions were as follow: 35μL of toluene was used as extraction solvent and 0.2mmol L-1 Triton X-100 was chosen as the surfactant to enhance the emulsification. Under the optimum experimental conditions, the limit of detections (LODs) of the method was ranged between 0.01 and 0.05μgL(-1) and the relative standard deviations (RSDs) were 2.9-8.1%. The calibration curve was linear in the range of 0.1-50.0μgL(-1), with the correlation coefficients (r) varying from 0.9949 to 0.9991. Finally, the developed method has been successfully applied to the determination of eight organophosphorus pesticides in river, reservoir and well water samples with recoveries between 82.1% and 98.7%.

  1. Relief of knee flexion contracture and gait improvement following adaptive training for an assist device in a transtibial amputee: A case study. (United States)

    Kim, Sol-Bi; Ko, Chang-Yong; Son, Jinho; Kang, Sungjae; Ryu, Jeicheong; Mun, Museong


    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.

  2. Ultrasonic Substrate Vibration-Assisted Drop Casting (SVADC) for the Fabrication of Photovoltaic Solar Cell Arrays and Thin-Film Devices (United States)

    Eslamian, Morteza; Zabihi, Fatemeh


    A simple, low-cost, versatile, and potentially scalable casting method is proposed for the fabrication of micro- and nano-thin films, herein termed as ultrasonic "substrate vibration-assisted drop casting" (SVADC). The impingement of a solution drop onto a substrate in a simple process called drop casting, usually results in spreading of the liquid solution and the formation of a non-uniform thin solid film after solvent evaporation. Our previous and current supporting results, as well as few similar reports by others, confirm that imposing ultrasonic vibration on the substrate can simply convert the uncontrollable drop casting method into a controllable coating technique. Therefore, the SVADC may be used to fabricate an array of emerging thin-film solar cells, such as polymer, perovskite, and quantum-dot solar cells, as well as other small thin-film devices, in a roll-to-roll and automated fabrication process. The preliminary results demonstrate a ten-fold increase in electrical conductivity of PEDOT: PSS made by SVADC compared with the film made by conventional drop casting. Also, simple planar perovskite solar cells made here using SVADC show promising performance with an efficiency of over 3 % for a simple structure without performing process optimization or using expensive materials and treatments.

  3. 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 (United States)

    Chivukula, V. Keshav; McGah, Patrick; Prisco, Anthony; Beckman, Jennifer; Mokadam, Nanush; Mahr, Claudius; Aliseda, Alberto


    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

  4. Self-care and communication issues at the end of life of recipients of a left-ventricular assist device as destination therapy. (United States)

    Ben Gal, Tuvia; Jaarsma, Tiny


    The purpose of this review is to provide an overview of self- care and communication issues at the end of life of patients with left-ventricular assist devices (LVADs) for destination therapy, based on recent research on end-of-life communication in other diseases. For many patients with advanced heart failure, LVADs as destination therapy improve survival and quality of life. However, LVADs can be associated with complications, new comorbidities or worsening of previous conditions, resulting in decreased quality of life and limited prognosis, raising the need for planning palliative and end-of-life care. Open communication addressing the consequences of the LVAD implantation for daily life and the future (including advance directives) is advised in different stages of the treatment, involving a multidisciplinary team taking care of these complex patients and their caregivers. Healthcare professionals treating patients before and after LVAD implantation need to take an active role in end-of-life discussions and be able to communicate information regarding expected complications, quality of life and prognosis to the patients and caregivers. Research is needed addressing optimal ways and timing of communication with LVAD patients and families.

  5. The CentriMag centrifugal blood pump as a benchmark for in vitro testing of hemocompatibility in implantable ventricular assist devices. (United States)

    Chan, Chris H H; Pieper, Ina Laura; Hambly, Rebecca; Radley, Gemma; Jones, Alyssa; Friedmann, Yasmin; Hawkins, Karl M; Westaby, Stephen; Foster, Graham; Thornton, Catherine A


    Implantable ventricular assist devices (VADs) have proven efficient in advanced heart failure patients as a bridge-to-transplant or destination therapy. However, VAD usage often leads to infection, bleeding, and thrombosis, side effects attributable to the damage to blood cells and plasma proteins. Measuring hemolysis alone does not provide sufficient information to understand total blood damage, and research exploring the impact of currently available pumps on a wider range of blood cell types and plasma proteins such as von Willebrand factor (vWF) is required to further our understanding of safer pump design. The extracorporeal CentriMag (Thoratec Corporation, Pleasanton, CA, USA) has a hemolysis profile within published standards of normalized index of hemolysis levels of less than 0.01 g/100 L at 100 mm Hg but the effect on leukocytes, vWF multimers, and platelets is unknown. Here, the CentriMag was tested using bovine blood (n = 15) under constant hemodynamic conditions in comparison with a static control for total blood cell counts, hemolysis, leukocyte death, vWF multimers, microparticles, platelet activation, and apoptosis. The CentriMag decreased the levels of healthy leukocytes (P pump which could be used as a standard in blood damage assays to inform the design of new implantable blood pumps.

  6. Current status of the gyro centrifugal blood pump--development of the permanently implantable centrifugal blood pump as a biventricular assist device (NEDO project). (United States)

    Nosé, Yukihiko; Furukawa, Kojiro


    The New Energy and Industrial Technology Development Organization (NEDO) project was started in 1995. The goal is the development of a multipurpose, totally implantable biventricular assist device (BVAD) that can be used for any patient who suffers from severe heart failure. Our C1E3 (two-week pump) centrifugal pump, called the Gyro pump, has three design characteristics: a magnetic coupling and double pivot bearing system, an eccentric inlet port, and secondary vanes on the bottom of the impeller. The pump was miniaturized. The C1E3 evolved into the NEDO PI-601, a totally implantable centrifugal pump for BVAD. The current NEDO PI-710 pump (five-year pump) system includes a centrifugal pump with pivot bearings, a hydraulically-levitated impeller, an rpm-controlled miniaturized actuator (all-in-one actuator plus controller), an emergency clamp on the left outflow, and a Frank-Starling-type flow control. The final mass production model is now finalized, and the final animal study and two-year endurance studies are ongoing.

  7. Central and peripheral blood flow during exercise with a continuous-flow left ventricular assist device: constant versus increasing pump speed: a pilot study

    DEFF Research Database (Denmark)

    Brassard, Patrice; Jensen, Annette S; Nordsborg, Nikolai


    with work rate would increase organ blood flow. Methods and Results- Invasively determined CO and leg blood flow and Doppler-determined cerebral perfusion were measured during 2 incremental cycle exercise tests on the same day in 8 patients provided with a HeartMate II LVAD. In random order, patients......Background- End-stage heart failure is associated with impaired cardiac output (CO) and organ blood flow. We determined whether CO and peripheral perfusion are maintained during exercise in patients with an axial-flow left ventricular assist device (LVAD) and whether an increase in LVAD pump speed...... exercised both with a constant (˜9775 rpm) and with an increasing pump speed (+400 rpm per exercise stage). At 60 W, the elevation in CO was more pronounced with increased pump speed (8.7±0.6 versus 8.1±1.1 L · min(-1); mean±SD; P=0.05), but at maximal exercise increases in CO (from 7.0±0.9 to 13.6±2.5 L...

  8. PLAD (personal lift assistive device) stiffness affects the lumbar flexion/extension moment and the posterior chain EMG during symmetrical lifting tasks. (United States)

    Frost, David M; Abdoli-E, Mohammad; Stevenson, Joan M


    The PLAD (personal lift assistive device) was designed to reduce the lumbar moment during lifting and bending tasks via elastic elements. This investigation examined the effects of modulating the elastic stiffness. Thirteen men completed 90 lifts (15 kg) using 6 different PLAD stiffnesses in stoop, squat and freestyle lifting postures. The activity of 8 muscles were recorded (latissimus dorsi, thoracic and lumbar erector spinae, rectus abdominis, external oblique, gluteus maximus, biceps femoris and rectus femoris), 3D electromagnetic sensors tracked the motion of each segment and strain gauges measured the elastic tension. EMG data were rectified, filtered, normalized and integrated as a percentage of the lifting task. The highest PLAD tension elicited the greatest reduction in erector spinae activity (mean of thoracic and lumbar) in comparison to the no-PLAD condition for the stoop (37%), squat (38%), and freestyle (37%) lifts, while prompting comparable reductions in gluteus maximums and biceps femoris activity. The highest PLAD stiffness also elicited the greatest reduction in the integrated L4/L5 flexion moment for the stoop (19.0%), squat (18.4%) and freestyle (17.4%) lifts without changing peak lumbar flexion. Each increase in PLAD stiffness further reduced the muscle activity of the posterior chain and the dynamic lumbar moment.

  9. Pulsatile Support Mode of BJUT-II Ventricular Assist Device (VAD) has Better Hemodynamic Effects on the Aorta than Constant Speed Mode: A Primary Numerical Study. (United States)

    Gu, Kaiyun; Gao, Bin; Chang, Yu; Zeng, Yi


    BACKGROUND BJUT-II VAD is a novel left ventricular assist device (LVADs), directly implanted into the ascending aorta. The pulsatile support mode is proposed to achieve better unloading performance than constant speed mode. However, the hemodynamic effects of this support mode on the aorta are still unclear. The aim of this study was to clarify the hemodynamic effects BJUT-II VAD under pulsatile support mode on the aorta. MATERIAL AND METHODS Computational fluid dynamics (CFD) studies, based on a patient-specific aortic geometric model, were conducted. Wall shear stress (WSS), averaged WSS (avWSS), oscillatory shear index (OSI), and averaged helicity density (Ha) were calculated to compare the differences in hemodynamic effects between pulsatile support mode and constant speed mode. RESULTS The results show that avWSS under pulsatile support mode is significantly higher than that under constant speed mode (0.955Pa vs. 0.675Pa). Similarly, the OSI value under pulsatile mode is higher than that under constant speed mode (0.104 vs. 0.057). In addition, Ha under pulsatile mode for all selected cross-sections is larger than that under constant mode. CONCLUSIONS BJUT-II VAD, under pulsatile control mode, may prevent atherosclerosis lesions and aortic remodeling. The precise effects of pulsatile support mode on atherosclerosis and aortic remodeling need to be further studied in animal experiments.

  10. Perioperative care in an adolescent patient with heparin-induced thrombocytopenia for placement of a cardiac assist device and heart transplantation: case report and literature review

    Directory of Open Access Journals (Sweden)

    Kamata M


    Full Text Available Mineto Kamata,1 Roby Sebastian,1,2 Patrick I McConnell,3 Daniel Gomez,4 Aymen Naguib,1,2 Joseph D Tobias1,2,5 1Department of Anesthesiology and Pain Medicine, Nationwide Children’s Hospital, 2Department of Anesthesiology and Pain Medicine, The Ohio State University College of Medicine, 3Department of Cardiothoracic Surgery, Nationwide Children’s Hospital, 4Cardiovascular Perfusion Services and Heart Center, Nationwide Children’s Hospital and The Ohio State University, 5Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA Abstract: Heparin-induced thrombocytopenia (HIT can cause life-threatening complications following the administration of heparin. Discontinuation of all sources of heparin exposure and the use of alternative agents for anticoagulation are necessary when HIT is suspected or diagnosed. We present the successful use of bivalirudin anticoagulation in an adolescent patient during cardiopulmonary bypass who underwent both placement of a left ventricular assist device and subsequent heart transplantation within a 36-hour period. The pathophysiology and diagnosis of HIT are reviewed, previous reports of the use of direct thrombin inhibitors for cardiac surgery are presented, and potential dosing regimens for bivalirudin are discussed. Keywords: bivalirudin, anticoagulation, cardiopulmonary bypass, heart transplant

  11. Educational resources for patients considering a left ventricular assist device: a cross-sectional review of internet, print, and multimedia materials. (United States)

    Iacovetto, Matthew C; Matlock, Daniel D; McIlvennan, Colleen K; Thompson, Jocelyn S; Bradley, William; LaRue, Shane J; Allen, Larry A


    Left ventricular assist devices (LVADs) are being used with increasing frequency to treat severe heart failure. Patients seek out informational resources when considering implantation. The primary study objective was to characterize the scope and quality of available LVAD educational materials. In July 2013, we performed a cross-sectional search of Internet, print, and multimedia resources available to patients considering LVAD. Written materials materials clearly directed to healthcare professionals were excluded. Seventy-seven materials met inclusion criteria. Potential benefits of LVAD therapy were discussed in all (n=77), whereas less often mentioned were risks (n=43), lifestyle considerations (n=29), surgical details (n=26), caregiver information (n=9), and hospice or palliative care (n=2). Of the 14 materials that recognized a decision or alternate treatment option, 7 used outdated statistics, 12 scored above an eighth grade reading comprehension level, and 12 met materials use outdated statistics, are above the reading level of average Americans, and are biased toward accepting LVAD therapy. There is no tool that would qualify as a formal decision aid. © 2014 American Heart Association, Inc.

  12. Assistive Technology Based on Robotics and Rise in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaoyu; WANG Kaixuan


    The concept of assistive technology based on robotics,rehabilitation robot and intelligent assistive devices.Domestic intelligence assistive devices include intelligent prosthetics,intelligent orthotics,intelligent walker,assistive devices for smart home environment control,intelligent life assistive devices; Domestic intelligent rehabilitation robot include upper limb rehabilitation robot,hand rehabilitation robot,lower limb rehabilitation robot,robotic smart wheelchair,intelligent nursing bed,daily care robot,the development trend of intelligent assistive devices and rehabilitation robot.

  13. Patient-Reported Health-Related Quality of Life Is a Predictor of Outcomes in Ambulatory Heart Failure Patients Treated With Left Ventricular Assist Device Compared With Medical Management: Results From the ROADMAP Study (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management). (United States)

    Stehlik, Josef; Estep, Jerry D; Selzman, Craig H; Rogers, Joseph G; Spertus, John A; Shah, Keyur B; Chuang, Joyce; Farrar, David J; Starling, Randall C


    The prospective observational ROADMAP study (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management) demonstrated that ambulatory advanced heart failure patients selected for left ventricular assist device (LVAD) were more likely to be alive at 1 year on original therapy with ≥75-m improvement in 6-minute walk distance compared with patients assigned to optimal medical management. Whether baseline health-related quality of life (hrQoL) resulted in a heterogeneity of this treatment benefit is unknown. Patient-reported hrQoL was assessed with EuroQol questionnaire and visual analogue scale (VAS). We aimed to identify predictors of event-free survival and survival with acceptable hrQoL (VAS≥60). LVAD patients had significant improvement in 3 of 5 EuroQol dimensions (Pmanagement. Among patients with baseline VASmanagement patients compared with those assigned to LVAD (58±7% versus 82±5%; P=0.004). No such difference was seen if baseline VAS was ≥55 (70±7% versus 75±9%; P=0.79). Survival on original therapy with acceptable quality of life was also more likely with LVAD versus optimal medical management if baseline VAS was <55, whereas outcomes in patients with higher baseline VAS scores were similar regardless of treatment assignment (P=0.046 for treatment arm and baseline VAS interaction). LVAD therapy resulted in improvement of patient health status in heart failure patients with low self-reported hrQoL, but not in patients with acceptable quality of life at the time of LVAD implantation. Patient-reported hrQoL should be integrated into decision making concerning the use and timing of LVAD therapy in heart failure patients who are symptom limited but remain ambulatory. URL: Unique identifier: NCT01452802. © 2017 American Heart Association, Inc.

  14. A new approach to heart valve tissue engineering: mimicking the heart ventricle with a ventricular assist device in a novel bioreactor. (United States)

    Kaasi, Andreas; Cestari, Idágene A; Stolf, Noedir A G; Leirner, Adolfo A; Hassager, Ole; Cestari, Ismar N


    The 'biomimetic' approach to tissue engineering usually involves the use of a bioreactor mimicking physiological parameters whilst supplying nutrients to the developing tissue. Here we present a new heart valve bioreactor, having as its centrepiece a ventricular assist device (VAD), which exposes the cell-scaffold constructs to a wider array of mechanical forces. The pump of the VAD has two chambers: a blood and a pneumatic chamber, separated by an elastic membrane. Pulsatile air-pressure is generated by a piston-type actuator and delivered to the pneumatic chamber, ejecting the fluid in the blood chamber. Subsequently, applied vacuum to the pneumatic chamber causes the blood chamber to fill. A mechanical heart valve was placed in the VAD's inflow position. The tissue engineered (TE) valve was placed in the outflow position. The VAD was coupled in series with a Windkessel compliance chamber, variable throttle and reservoir, connected by silicone tubings. The reservoir sat on an elevated platform, allowing adjustment of ventricular preload between 0 and 11 mmHg. To allow for sterile gaseous exchange between the circuit interior and exterior, a 0.2 µm filter was placed at the reservoir. Pressure and flow were registered downstream of the TE valve. The circuit was filled with culture medium and fitted in a standard 5% CO(2) incubator set at 37 °C. Pressure and flow waveforms were similar to those obtained under physiological conditions for the pulmonary circulation. The 'cardiomimetic' approach presented here represents a new perspective to conventional biomimetic approaches in TE, with potential advantages.

  15. Systemic Inflammatory Response Syndrome in End-Stage Heart Failure Patients Following Continuous-Flow Left Ventricular Assist Device Implantation: Differences in Plasma Redox Status and Leukocyte Activation. (United States)

    Mondal, Nandan K; Sorensen, Erik N; Pham, Si M; Koenig, Steven C; Griffith, Bartley P; Slaughter, Mark S; Wu, Zhongjun J


    The role of oxidative stress and leukocyte activation has not been elucidated in developing systemic inflammatory response syndrome (SIRS) in heart failure (HF) patients after continuous-flow left ventricular assist device (CF-LVAD) implantation. The objective of this study was to investigate the change of plasma redox status and leukocyte activation in CF-LVAD implanted HF patients with or without SIRS. We recruited 31 CF-LVAD implanted HF patients (16 SIRS and 15 non-SIRS) and 11 healthy volunteers as the control. Pre- and postimplant blood samples were collected from the HF patients. Plasma levels of oxidized low-density lipoprotein (oxLDL), malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD) in erythrocyte, myeloperoxidase (MPO), and polymorphonuclear elastase (PMN-elastase) were measured. The HF patients had a preexisting condition of oxidative stress than healthy controls as evident from the higher oxLDL and MDA levels as well as depleted SOD and TAC. Leukocyte activation in terms of higher plasma MPO and PMN-elastase was also prominent in HF patients than controls. Persistent oxidative stress and reduced antioxidant status were found to be more belligerent in HF patients with SIRS after the implantation of CF-LVAD when compared with non-SIRS patients. Similar to oxidative stress, the activation of blood leukocyte was significantly highlighted in SIRS patients after implantation compared with non-SIRS. We identified that the plasma redox status and leukocyte activation became more prominent in CF-LVAD implanted HF patients who developed SIRS. Our findings suggest that plasma biomarkers of oxidative stress and leukocyte activation may be associated with the development of SIRS after CF-LVAD implant surgery.

  16. Continuous-flow left ventricular assist device therapy in patients with preoperative hepatic failure: are we pushing the limits too far? (United States)

    Weymann, Alexander; Patil, Nikhil P; Sabashnikov, Anton; Mohite, Phrashant N; Garcia Saez, Diana; Bireta, Christian; Wahlers, Thorsten; Karck, Matthias; Kallenbach, Klaus; Ruhparwar, Arjang; Fatullayev, Javid; Amrani, Mohamed; De Robertis, Fabio; Bahrami, Toufan; Popov, Aron-Frederik; Simon, Andre R


    The purpose of this study was to evaluate the effects and outcome of continuous-flow left ventricular assist device (cf-LVAD) therapy in patients with preoperative acute hepatic failure. The study design was a retrospective review of prospectively collected data. Included were 42 patients who underwent cf-LVAD implantation (64.3% HeartMate II, 35.7% HeartWare) between July 2007 and May 2013 with preoperative hepatic failure defined as elevation of greater than or equal to two liver function parameters above twice the upper normal range. Mean patient age was 35 ± 12.5 years, comprising 23.8% females. Dilated cardiomyopathy was present in 92.9% of patients (left ventricular ejection fraction 17.3 ± 5.9%). Mean support duration was 511 ± 512 days (range: 2-1996 days). Mean preoperative laboratory parameters for blood urea nitrogen, serum creatinine, total bilirubin, and alanine aminotransferase were 9.5 ± 5.4 mg/dL, 110.3 ± 42.8 μmol/L, 51.7 ± 38.3 mmol/L, and 242.1 ± 268.6 U/L, respectively. All parameters decreased significantly 1 month postoperatively. The mean preoperative modified Model for Endstage Liver Disease excluding international normalized ratio score was 16.03 ± 5.57, which improved significantly after cf-LVAD implantation to 10.62 ± 5.66 (P failure over the follow-up period. Patients with preexisting acute hepatic failure are reasonable candidates for cf-LVAD implantation, with excellent rates of recovery and survival, suggesting that cf-LVAD therapy should not be denied to patients merely on grounds of "preoperative elevated liver enzymes/hepatopathy."

  17. Pulsatile support using a rotary left ventricular assist device with an electrocardiography-synchronized rotational speed control mode for tracking heart rate variability. (United States)

    Arakawa, Mamoru; Nishimura, Takashi; Takewa, Yoshiaki; Umeki, Akihide; Ando, Masahiko; Kishimoto, Yuichiro; Kishimoto, Satoru; Fujii, Yutaka; Date, Kazuma; Kyo, Shunei; Adachi, Hideo; Tatsumi, Eisuke


    We previously developed a novel control system for a continuous-flow left ventricular assist device (LVAD), the EVAHEART, and demonstrated that sufficient pulsatility can be created by increasing its rotational speed in the systolic phase (pulsatile mode) in a normal heart animal model. In the present study, we assessed this system in its reliability and ability to follow heart rate variability. We implanted an EVAHEART via left thoracotomy into five goats for the Study for Fixed Heart Rate with ventricular pacing at 80, 100, 120 and 140 beats/min and six goats for the Study for native heart rhythm. We tested three modes: the circuit clamp, the continuous mode and the pulsatile mode. In the pulsatile mode, rotational speed was increased during the initial 35 % of the RR interval by automatic control based on the electrocardiogram. Pulsatility was evaluated by pulse pressure and dP/dt max of aortic pressure. As a result, comparing the pulsatile mode with the continuous mode, the pulse pressure was 28.5 ± 5.7 vs. 20.3 ± 7.9 mmHg, mean dP/dt max was 775.0 ± 230.5 vs 442.4 ± 184.7 mmHg/s at 80 bpm in the study for fixed heart rate, respectively (P mode for continuous-flow LVADs reliably provided physiological pulsatility with following heart rate variability.

  18. Body position and activity, but not heart rate, affect pump flows in patients with continuous-flow left ventricular assist devices. (United States)

    Muthiah, Kavitha; Gupta, Sunil; Otton, James; Robson, Desiree; Walker, Robyn; Tay, Andre; Macdonald, Peter; Keogh, Anne; Kotlyar, Eugene; Granger, Emily; Dhital, Kumud; Spratt, Phillip; Jansz, Paul; Hayward, Christopher S


    The aim of this study was to determine the contribution of pre-load and heart rate to pump flow in patients implanted with continuous-flow left ventricular assist devices (cfLVADs). Although it is known that cfLVAD pump flow increases with exercise, it is unclear if this increment is driven by increased heart rate, augmented intrinsic ventricular contraction, or enhanced venous return. Two studies were performed in patients implanted with the HeartWare HVAD. In 11 patients, paced heart rate was increased to approximately 40 beats/min above baseline and then down to approximately 30 beats/min below baseline pacing rate (in pacemaker-dependent patients). Ten patients underwent tilt-table testing at 30°, 60°, and 80° passive head-up tilt for 3 min and then for a further 3 min after ankle flexion exercise. This regimen was repeated at 20° passive head-down tilt. Pump parameters, noninvasive hemodynamics, and 2-dimensional echocardiographic measures were recorded. Heart rate alteration by pacing did not affect LVAD flows or LV dimensions. LVAD pump flow decreased from baseline 4.9 ± 0.6 l/min to approximately 4.5 ± 0.5 l/min at each level of head-up tilt (p heart rate, but they change significantly with body position and passive filling. Previously demonstrated exercise-induced changes in pump flows may be related to altered loading conditions, rather than changes in heart rate. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  19. Ventricular assist device elicits serum natural IgG that correlates with the development of primary graft dysfunction following heart transplantation. (United States)

    See, Sarah B; Clerkin, Kevin J; Kennel, Peter J; Zhang, Feifan; Weber, Matthew P; Rogers, Kortney J; Chatterjee, Debanjana; Vasilescu, Elena R; Vlad, George; Naka, Yoshifumi; Restaino, Susan W; Farr, Maryjane A; Topkara, Veli K; Colombo, Paolo C; Mancini, Donna M; Schulze, P Christian; Levin, Bruce; Zorn, Emmanuel


    Pre-transplant sensitization is a limiting factor in solid-organ transplantation. In heart transplants, ventricular assist device (VAD) implantation has been associated with sensitization to human leukocyte antigens (HLA). The effect of VAD on non-HLA antibodies is unclear. We have previously shown that polyreactive natural antibodies (Nabs) contribute to pre-sensitization in kidney allograft recipients. Here we assessed generation of Nabs after VAD implantation in pre-transplant sera and examined their contribution to cardiac allograft outcome. IgM and IgG Nabs were tested in pre-transplant serum samples collected from 206 orthotopic heart transplant recipients, including 128 patients with VAD (VAD patients) and 78 patients without VAD (no-VAD patients). Nabs were assessed by testing serum reactivity to apoptotic cells by flow cytometry and to the generic oxidized epitope, malondialdehyde, by enzyme-linked immunosorbent assay. No difference was observed in serum levels of IgM Nabs between VAD and no-VAD patients. However, serum IgG Nabs levels were significantly increased in VAD compared with no-VAD patients. This increase was likely due to the presence of the VAD, as revealed by lower serum IgG Nabs levels before implantation. Elevated pre-transplant IgG Nabs level was associated with development of primary graft dysfunction (PGD). Our study demonstrates that VAD support elicits IgG Nabs reactive to apoptotic cells and oxidized epitopes. These findings further support broad and non-specific B-cell activation by VAD, resulting in IgG sensitization. Moreover, the association of serum IgG Nabs levels with development of PGD suggests a possible role for these antibodies in the inflammatory reaction accompanying this complication. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  20. Persistent blood stream infection in patients supported with a continuous-flow left ventricular assist device is associated with an increased risk of cerebrovascular accidents. (United States)

    Trachtenberg, Barry H; Cordero-Reyes, Andrea M; Aldeiri, Molham; Alvarez, Paulino; Bhimaraj, Arvind; Ashrith, Guha; Elias, Barbara; Suarez, Erik E; Bruckner, Brian; Loebe, Matthias; Harris, Richard L; Zhang, J Yi; Torre-Amione, Guillermo; Estep, Jerry D


    Common adverse events in patients supported with Continuous-flow left ventricular assist devices (CF-LVAD) include infections and cerebrovascular accidents (CVA). Some studies have suggested a possible association between blood stream infection (BSI) and CVA. Medical records of patients who received Heartmate II (HMII) CF-LVADs in 2008-2012 at a single center were reviewed. CVA was categorized as either hemorrhagic (HCVA) or ischemic (ICVA). BSI was divided into persistent (pBSI) and nonpersistent (non-pBSI). pBSI was defined as BSI with the same organism on repeated blood culture >72 hours from initial blood culture despite antibiotics. Univariate and multivariate analyses were performed to determine predictors. A total of 149 patients had HMII implanted; 76% were male, and the overall mean age was 55.4 ± 13 years. There were a total of 19 (13%) patients who had CVA (7 HCVA and 12 ICVA) at a median of 295 days (range 5-1,096 days) after implantation. There were a total of 28 (19%) patients with pBSI and 17 (11%) patients with non-pBSI. Patients with pBSI had a trend toward greater BMI (31 kg/m(2) vs 27 kg/m(2); P = .09), and longer duration of support (1,019 d vs 371 d; P CVA on multivariate analysis (odds ratio [OR] 5.97; P = .003) as well as persistent Pseudomonas aeruginosa infection (OR 4.54; P = .048). Persistent BSI is not uncommon in patients supported by CF-LVAD and is highly associated with all-cause CVA and increased all-cause mortality. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Preoperative Proteinuria and Reduced Glomerular Filtration Rate Predicts Renal Replacement Therapy in Patients Supported With Continuous-Flow Left Ventricular Assist Devices. (United States)

    Topkara, Veli K; Coromilas, Ellie J; Garan, Arthur Reshad; Li, Randall C; Castagna, Francesco; Jennings, Douglas L; Yuzefpolskaya, Melana; Takeda, Koji; Takayama, Hiroo; Sladen, Robert N; Mancini, Donna M; Naka, Yoshifumi; Radhakrishnan, Jai; Colombo, Paolo C


    Renal failure requiring renal replacement therapy (RRT) has detrimental effects on quality of life and survival of patients with continuous-flow left ventricular assist devices (CF-LVADs). Current guidelines do not offer a decision-making algorithm for CF-LVAD candidates with poor baseline renal function. Objective of this study was to identify risk factors associated with RRT after CF-LVAD implantation. Three hundred and eighty-nine consecutive patients underwent contemporary CF-LVAD implantation at the Columbia University Medical Center between January 2004 and August 2015. Baseline demographics, comorbid conditions, clinical risk scores, and renal function were analyzed in patients with or without RRT after CF-LVAD implantation. Time-dependent receiver-operating characteristic curve analysis was performed to define optimal cutoffs for continuous risk factors. Forty-four patients (11.6%) required RRT during a median follow-up of 9.9 months. Patients requiring RRT had significantly worse renal function, lower hemoglobin, and increased proteinuria at baseline. Low estimated glomerular filtration rate (proteinuria (urine protein to creatinine ratio ≥0.55 mg/mg) were significant predictors of RRT after CF-LVAD support. Dipstick proteinuria was also a significant predictor of RRT after CF-LVAD implantation. Patients with both low estimated glomerular filtration rate and proteinuria had highest risk of RRT (63.6%) compared with those with either low estimated glomerular filtration rate or proteinuria (18.7%) and those with neither of these risk factors (2.7%) at 1-year follow-up (log-rank Pproteinuria are predictors RRT after CF-LVAD implantation and should be routinely assessed in CF-LVAD candidates to guide decision making. © 2016 American Heart Association, Inc.

  2. Analysis of heat generation of lithium ion rechargeable batteries used in implantable battery systems for driving undulation pump ventricular assist device. (United States)

    Okamoto, Eiji; Nakamura, Masatoshi; Akasaka, Yuhta; Inoue, Yusuke; Abe, Yusuke; Chinzei, Tsuneo; Saito, Itsuro; Isoyama, Takashi; Mochizuki, Shuichi; Imachi, Kou; Mitamura, Yoshinori


    We have developed internal battery systems for driving an undulation pump ventricular assist device using two kinds of lithium ion rechargeable batteries. The lithium ion rechargeable batteries have high energy density, long life, and no memory effect; however, rise in temperature of the lithium ion rechargeable battery is a critical issue. Evaluation of temperature rise by means of numerical estimation is required to develop an internal battery system. Temperature of the lithium ion rechargeable batteries is determined by ohmic loss due to internal resistance, chemical loss due to chemical reaction, and heat release. Measurement results of internal resistance (R(cell)) at an ambient temperature of 37 degrees C were 0.1 Omega in the lithium ion (Li-ion) battery and 0.03 Omega in the lithium polymer (Li-po) battery. Entropy change (DeltaS) of each battery, which leads to chemical loss, was -1.6 to -61.1 J/(mol.K) in the Li-ion battery and -9.6 to -67.5 J/(mol.K) in the Li-po battery depending on state of charge (SOC). Temperature of each lithium ion rechargeable battery under a discharge current of 1 A was estimated by finite element method heat transfer analysis at an ambient temperature of 37 degrees C configuring with measured R(cell) and measured DeltaS in each SOC. Results of estimation of time-course change in the surface temperature of each battery coincided with results of measurement results, and the success of the estimation will greatly contribute to the development of an internal battery system using lithium ion rechargeable batteries.

  3. Design and experiment on handheld air-assisted pollination device%手持式风送授粉机研制与试验

    Institute of Scientific and Technical Information of China (English)

    丁素明; 薛新宇; 蔡晨; 秦维彩; 方金豹; 孙竹


    Pollination is a very important process for high yield and quality of fruits production. The artificial and bee pollinations are wildly used in fruits production, but they are unadaptable to large scale production. So a kind of handheld air-assisted pollination device was developed. Through theoretical calculation, the air supply device was determined to adopt 6 impellers, the impeller diameter is 38 mm and the guide blades width is 18 mm. The motor is driven by DC power. A wind velocity indicator was used and the test ring was put at 500 mm ahead of the air inlet which is connected with a set of rams to fan pipes. The ram’s diameter is 38 mm, same as the impeller. The results of fan performance test showed that the air volume was 3.0×10-3m3/s at 8 000 r/min of fan speed, which can meet the design requirements. The highest total pressure efficiency is 43% at 9 000 r/min of fan speed. With the speed increase, the total pressure efficiency dropped rapidly but the power increased and the variation trends of the air volume and air pressure are not significant. The fan property was tested and the performance curve graphic was drawn. The air velocity field at different rotational speeds of the handheld air-assisted pollination device were studied and validated by the experiment data. The results showed that the velocity of central plane diffused at a fixed angle and decayed along the centre line, and the theoratical values closely related to the experiment data. In order to study the effect of airflow speed on pollination, the basic principle of pneumatic pollination was analyzed. Tests were conducted to validate the effect of airflow speed on pollens distribution based on pollens density, horizontal distribution and vertical distribution in the lab. The results show that the flow rate of nozzle is affected by wind velocity significantly. When the winds velocity reaches 25 m/s, the variation trends of the flow rate of nozzle are not significant with the speed increase

  4. Systematic evaluation of non-invasive brain-computer interfaces as assistive devices for persons with severe motor impairment based on a user-centred approach – in controlled settings and independent use


    Holz, Elisa Mira


    Brain-computer interfaces (BCIs) are devices that translate signals from the brain into control commands for applications. Within the last twenty years, BCI applications have been developed for communication, environmental control, entertainment, and substitution of motor functions. Since BCIs provide muscle independent communication and control of the environment by circumventing motor pathways, they are considered as assistive technologies for persons with neurological and neurodegenerative...

  5. An assistive device designed to convey independent donning of a shuttle lock trans-tibial prosthesis for a multiple limb amputee. (United States)

    Tamir, E; Heim, M; Oppenheim, U; Siev-Ner, I


    This contribution describes a simple device designed to convey independent donning of a shuttle lock trans-tibial prosthesis for a multiple limb amputee. The device is made of a post with a shuttle lock mechanism at one end and a plate covered by rubber at the other end. This device enables correct positioning of the silicone liner and independent attachment to the prosthesis.

  6. GP-support by means of AGnES-practice assistants and the use of telecare devices in a sparsely populated region in Northern Germany – proof of concept

    Directory of Open Access Journals (Sweden)

    Scriba Sibylle


    Full Text Available Abstract Background In many rural regions in Germany, the proportion of the elderly population increases rapidly. Simultaneously, about one-third of the presently active GPs will retire until 2010. Often it is difficult to find successors for vacant GP-practices. These regions require innovative concepts to avoid the imminent shortage in primary health care. The AGnES-concept comprises the delegation of GP-home visits to qualified AGnES-practice assistants (AGnES: GP-supporting, community-based, e-health-assisted, systemic intervention. Main objectives were the assessment of the acceptance of the AGnES-concept by the participating GPs, patients, and AGnES-practice assistants, the kind of delegated tasks, and the feasibility of home telecare in a GP-practice. Methods In this paper, we report first results of the implementation of this concept in regular GP-practices, conducted November 2005 – March 2007 on the Island of Rügen, Mecklenburg-Western Pomerania, Germany. This study was meant as a proof of concept. The GP delegated routine home-visits to qualified practice employees (here: registered nurses. Eligible patients were provided with telecare-devices to monitor disease-related physiological values. All delegated tasks, modules conducted and questionnaire responses were documented. The participating patients were asked for their acceptance based on standardized questionnaires. The GPs and AGnES-practice assistants were asked for their judgement about different project components, the quality of health care provision and the competences of the AGnES-practice assistants. Results 550 home visits were conducted. 105 patients, two GPs and three AGnES-practice assistants (all registered nurses participated in the project. 48 patients used telecare-devices to monitor health parameters. 87.4% of the patients accepted AGnES-care as comparable to common GP-care. In the course of the project, the GPs delegated an increasing number of both monitoring

  7. Terapia de vacío como adyuvante para el uso de sustitutos dérmicos monocapa Combined use of vacuum assisted device and dermal monolayer substitutes

    Directory of Open Access Journals (Sweden)

    J.R. Martínez-Méndez


    conclusión, la aplicación de matrices de regeneración dérmica monocapa es segura, con una tasa de prendimiento de los injertos sobre ella del 85%. El uso del VAC® sobre las láminas monocapa de dermis sintética acorta el tiempo de integración de las mismas y el prendimiento de los injertos sobre ellas, con una tasa de complicaciones similar.Split thickness autografts are the gold standard for wound coverage. However, scars and retractions are frequent after skin grafts, and would be severe over special regions. Different authors avoid these complications using a dermal substitute interposed between the wound and the skin graft in the first surgical time. A prospective study was designed to evaluate the split thickness skin graft uptake time over a monolayer matrix, with and without a vacuum assisted therapy device (VAC®. Twenty patients with a full thickness wound over a special region were randomized between 2 groups. Epidemiological data and wound etiology (acute burn, burn sequelae or donor site after a fasciocutaneous flap raised were collected. Matriderm® (mono layer dermal substitute and a split thickness skin graft was applied over 10 cases (Group I. The dressing was changed after 7 days, and every 3-4 days until the skin graft was uptake and stable. Another 10 cases were treated with the same surgical strategy (Group II. After surgery, a vacuum assisted therapy device (VAC® was applied until the graft was uptake. The skin graft evaluation was done by a blind observer. All complications were reported until 3 months after the skin graft was stable. The homogeneity between groups was assessed. Averaged uptake time was 17, 6 ± 8 days, and the total complication rate was 20%. Statistically differences were not found between the 2 groups for the complication rate. The uptake time was 21,4 ± 9 days in the Group I and 13,9 ± 4 days in the Group II. These differences was statically significative. As a conclusion, the use of monolayer dermal substitutes is safe

  8. Factors Affecting the Use of Assistive Device among Older Adults with Visual Disabilities and Policy Suggestions%视力残疾老年人使用辅助器具的影响因素及政策建议

    Institute of Scientific and Technical Information of China (English)

    张旭; 庄惠婷; 黄庆波; 陈功


    Based on the 2013 surveillance data on disabled people, It would be classified into three factors about the use of assistive device with older adults with visual disabilities, inclusive of the demographic characteristics, economical factors, environmental and psychological factors. Using the Binary Logistic Regression Model, the related factors are analyzed. The result indicated that, if older adults with visual disabilities are insufficient to deal with daily life, they are the higher frequency of the use of assistive devices. In addition, older adults with visual disabilities who have higher income level and participation in basic social insurance are the higher frequency of the use of assistive devices. Moreover, among older adults with visual disabilities, the higher frequency of the use of assistive devices is in the central region in China, the rate of using assistive devices of the elderly people with visual disabilities who have received government or social support within one year is higher than that of others.%利用2013年全国残疾人状况监测数据,分析可能影响视力残疾老年人辅助器具使用的人口学特征、经济因素、环境与心理因素.结果表明,生活自理能力不足的老年人更多使用辅助器具,收入水平较高、参与社会基本保险的老年人使用辅助器具水平较高,中部地区视力残疾老年人使用辅助器具较多,一年内接受过政府或社会组织走访慰问或社区服务的老年人辅助器具使用率较高.针对影响视力残疾人使用辅助器具的影响因素,提出加强残疾人辅助器具专项资金支持、促进社会力量帮扶和推动辅助器具研发满足残疾人多样化需求的建议.

  9. Relationship between pre-implant interleukin-6 levels, inflammatory response, and early outcome in patients supported by left ventricular assist device: a prospective study.

    Directory of Open Access Journals (Sweden)

    Raffaele Caruso

    Full Text Available PURPOSE: The immune response is crucial in the development of multi-organ failure (MOF and complications in end-stage heart failure patients supported by left ventricular assist device (LVAD. However, at pre-implant, the association between inflammatory state and post-LVAD outcome is not yet clarified. Aim of the study was to assess the relationship among pre-implant levels of immune-related cytokines, postoperative inflammatory response and 3-month outcome in LVAD-patients. METHODS: In 41 patients undergoing LVAD implantation, plasma levels of interleukin (IL-6, IL-8, crucial for monocyte modulation, and urine neopterin/creatinine ratio (Neo/Cr, marker of monocyte activation, were assessed preoperatively, at 3 days, 1 and 4 weeks post-LVAD. MOF was evaluated by total sequential organ failure assessment (tSOFA score. Intensive care unit (ICU-death and/or post-LVAD tSOFA ≥11 was considered as main adverse outcome. Length of ICU-stay, 1 week-tSOFA score, hospitalisation and 3-month survival were considered additional end-points. RESULTS: During ICU-stay, 8 patients died of MOF, while 8 of the survivors experienced severe MOF with postoperative tSOFA score ≥11. Pre-implant level of IL-6 ≥ 8.3 pg/mL was identified as significant marker of discrimination between patients with or without adverse outcome (OR 6.642, 95% CI 1.201-36.509, p = 0.030. Patients were divided according to pre-implant IL-6 cutoff of 8.3 pg/ml in A [3.5 (1.2-6.1 pg/mL] and B [24.6 (16.4-38.0 pg/mL] groups. Among pre-implant variables, only white blood cells count was independently associated with pre-implant IL-6 levels higher than 8.3 pg/ml (OR 1.491, 95% CI 1.004-2.217, p = 0.048. The ICU-stay and hospitalisation resulted longer in B-group (p = 0.001 and p = 0.030, respectively. Postoperatively, 1 week-tSOFA score, IL-8 and Neo/Cr levels were higher in B-group. CONCLUSIONS: LVAD-candidates with elevated pre-implant levels of IL-6 are associated, after

  10. Comparison of cardiac power output and exercise performance in patients with left ventricular assist devices, explanted (recovered) patients, and those with moderate to severe heart failure. (United States)

    Jakovljevic, Djordje G; George, Robert S; Donovan, Gay; Nunan, David; Henderson, Keiran; Bougard, Robert S; Yacoub, Magdi H; Birks, Emma J; Brodie, David A


    Peak cardiac power output (CPO), as a direct measurement of overall cardiac function, has been shown to be a most powerful predictor of prognosis for patients with chronic heart failure. The present study assessed CPO and exercise performance in patients implanted with a left ventricular assist device (LVAD), those explanted due to myocardial recovery, and those with moderate to severe heart failure. Hemodynamic and respiratory gas exchange measurements were undertaken at rest and at peak graded exercise. These were performed in 54 patients-20 with moderate to severe heart failure, 18 with implanted LVADs, and 16 with explanted LVADs. At rest there was a nonsignificant difference in CPO among groups (p >0.05). Peak CPO was significantly higher in the explanted LVAD than in the heart failure and implanted LVAD groups (heart failure 1.90 +/- 0.45 W, implanted LVAD 2.37 +/- 0.55 W, explanted LVAD 3.39 +/- 0.61 W, p <0.01) as was peak cardiac output (heart failure 9.1 +/- 2.1 L/min, implanted LVAD 12.4 +/- 2.2 L/min, explanted LVD 14.6 +/- 2.9 L/min, p <0.01). Peak oxygen consumption was higher in the explanted LVAD than in the heart failure and implanted LVAD groups (heart failure 15.8 +/- 4.1 ml/kg/min, implanted LVAD 19.8 +/- 5.8 ml/kg/min, explanted LVAD 28.2 +/- 5.0 ml/kg/min, p <0.05) as was anaerobic threshold (heart failure 11.2 +/- 1.9 ml/kg/min, implanted LVAD 14.7 +/- 4.9 ml/kg/min, explanted LVAD 21.4 +/- 5.0 ml/kg/min, p <0.05). In conclusion, peak CPO differentiates well during cardiac restoration using LVADs and emphasizes the benefits of this therapy. CPO has the potential to be a key physiologic marker of heart failure severity and can guide management of patients with LVAD.

  11. The natriuretic peptide time-course in end-stage heart failure patients supported by left ventricular assist device implant: focus on NT-proCNP. (United States)

    Cabiati, M; Caruso, R; Caselli, C; Frigerio, M; Prescimone, T; Parodi, O; Giannessi, D; Del Ry, S


    This study aimed to evaluate left ventricular assist device (LVAD) effects on natriuretic peptide (NP) prohormone plasma levels in end-stage heart failure (HF) patients, especially NT-proCNP, in order to better characterize the NP system during hemodynamic recovery by LVAD. HF patients (n=17, NYHA III-IV) undergoing LVAD were studied: 6 died of multi-organ failure syndrome (NS) and 11 survived (S). Total sequential organ failure assessment (t-SOFA) score and blood samples were obtained at admission (T1) and at 24, 72h and 1, 2, 4 weeks (T2-T6) after LVAD. In S, NT-proANP and NT-proCNP significantly increased at 24h after implantation, reaching a reduction to basal levels at 4 weeks following LVAD [NT-proANP: T1 vs. T2 p=0.017, NT-proCNP: T1 vs. T2 p=0.028, T1 vs. T3 p=0.043]. Elevated NT-proBNP plasma levels were observed at all times. In NS, NP plasma levels sustained higher with respect to S. No statistical variation was observed for NT-proCNP and NT-proANP in S and NS while NT-proBNP reached significant differences at T4 in NS. Considering S+NS, only NT-proCNP strongly correlated with t-SOFA score at T1 (rho=0.554, p=0.04) while subdividing patients NT-proCNP positively correlated in NS with t-SOFA score (rho=0.988, p=0.002) only at T4. In NS a correlation between NT-proCNP and NT-proBNP at T1 was observed (rho=-0.900, p=0.037). Both IL-6 and TNF-alpha sustained higher in NS patients than in S; in particular, statistical significance was observed for IL-6. The study of new peptides, such as NT-proCNP, would provide additional information for identifying patients who are more likely to recover. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. An evaluation of the Wii Nunchuk as an alternative assistive device for people with intellectual and physical disabilities using switch controlled software



    Many people with intellectual disabilities also have physical difficulties which prevent them from using standard computer control devices. Custom made alternative devices for those with special needs can be expensive and the low unit turnover makes the prospect unattractive to potential manufacturers. One solution is to explore the potential of devices used in contemporary gaming technology, such as the Nintendo Wii. The Wii Nunchuk has the potential to replace joystick functions with the ad...

  13. Study of Hemolysis Performance for ChinaHeart Ventricular Assist Device%ChinaHeart心室辅助装置溶血性能研究

    Institute of Scientific and Technical Information of China (English)

    徐创业; 蔺嫦燕; 吴广辉; 刘修健; 杨朋; 渠文波


    目的 心室辅助装置在治疗心力衰竭过程中会对红细胞造成破坏,本文欲在ChinaHeart VAD 用于临床前测试其血泵的溶血性能,检验其血液相容性.方法 血泵的溶血性能测试包括体外实验和在体实验.体外溶血测试中,将血泵连接至体外模拟循环试验台,调节血泵转速和阻尼阀使输出流量为(5.0±0.25) L/min,平均压力为(100±3) mmHg,驱动抗凝后新鲜羊血,分别在泵转动前(0 min)、泵转动后60 min、120 min、180 min、240 min时检测血浆游离血红蛋白(Plasma Free Hemoglobin,FHB)含量和红细胞压积(Hct),计算血泵标准溶血指数(Normalized Index of Hemolysis,NIH).在体溶血测试中,取2只健康雄性小尾寒羊,麻醉后将血泵植入心尖,建立由左心室经心室辅助装置到降主动脉辅助循环旁路,控制血泵辅助流量占总心输出量的60%左右,进行在体辅助试验,定期抽血检测血浆FHB含量和Hct值.将体外和在体实验结果同国内外典型血泵比较,横向评测ChinaHeart VAD血泵溶血特性.结果 体外溶血实验中,血泵运行平稳,温度正常,无卡壳、漏液等状况.测得血泵体外NIH值为(0.0076±0.0016) g/100L.在体溶血实验中,2只羊分别成功辅助20天和38天,无明显肝肾功能障碍.FHB含量开始数天内呈上升趋势,分别达到最大值0.0846 g/L(存活20天)和1.0957g/L(存活38天),之后逐渐下降到术前水平.结论 ChinaHeart VAD血泵具有良好的体外和在体溶血性能,可以进行动物在体辅助长期存活实验.%Objective As ventricular assist device(VAD) may bring about damage to red blood cell(RBC) in treating heart failure, this paper attempts to test the hemolytic performance of ChinaHeart VAD blood pump before clinical application. Methods The hemolytic performance test includes vitro test and vivo test. In vitro test, we connected the blood pump with a simulative circulation test bed, adjusted its speed and orifice valve to make the

  14. Graft placement with an omental flap for ruptured infective common iliac aneurysm in a patient with a continuous flow left ventricular assist device: alternative surgical approach avoiding driveline injury and pathogen identification by 16S ribosomal DNA gene analysis. (United States)

    Akiyama, Masatoshi; Hayatsu, Yukihiro; Sakatsume, Ko; Fujiwara, Hidenori; Shimizu, Takuya; Akamatsu, Daijirou; Kakuta, Risako; Gu, Yoshiaki; Kaku, Mitsuo; Kumagai, Kiichiro; Kawamoto, Shunsuke; Goto, Hitoshi; Ohuchi, Noriaki; Saiki, Yoshikatsu


    Patients supported by mechanical circulatory support have to wait for longer periods for heart transplantation in Japan. Infective events are a major complication and influence survival. Here, we present the case of a patient with an implantable left ventricular assist device for 6 months who had the complication of ruptured infective common iliac aneurysm. Graft placement with an omental flap was successfully performed via the alternative surgical approach to avoid percutaneous driveline injury. In samples of aortic specimens, 16S ribosomal DNA gene analysis identified Helicobacter cinaedi. Complete removal of the infected tissue and correct pathogen identification may have been relevant to the good clinical course.


    Institute of Scientific and Technical Information of China (English)

    王冠生; 郑江华; 瓦哈甫·哈力克; 张洋; 姚聚慧


    在高度信息化时代,盲人导航/路径诱导辅具已经成为盲人生活中的一部分,关系到盲人生活质量的好坏,体现了社会文明程度的高低.首先对盲人导航/路径诱导辅具总体情况进行了概述;然后基于结构特征进行分类,并分别介绍了电子式行进辅具、移动式导盲机器人、智能盲杖以及智能导盲系统等辅具的历史发展、应用现状;最后指出了今后的发展趋势以及存在的问题.从现时导盲研究工作表明,研制开发更具人性化更适合于盲人导航/路径诱导的辅助工具具有重要的实用价值和社会现实意义.%In the era of high inforraatisation, the navigation/route guidance assistive devices for the blinds have become a part of the life for them. It relates to the quality of the life of the blinds and reflects the level of social civilisation. In this paper, first we outline the general situation of navigation/route guidance assistive devices for the blinds. Then we carry out the classification based on structural characteristics and introduce respectively the historical development and application status of the assistive devices such as electronic travel aids, mobile guide robot, intelligent blind cane, intelligent blind guiding system, etc. At last, we point out their development trends in the future and the problems existed. Current research work on blind navigation shows that it has the important practical value and social reality significance to develop the assistive devices which are much humanised and more suitable to the navigation/route guidance for the blinds.

  16. Effect of an interactive cardiopulmonary resuscitation assist device with an automated external defibrillator synchronised with a ventilator on the CPR performance of emergency medical service staff: a randomised simulation study. (United States)

    Nitzschke, Rainer; Doehn, Christoph; Kersten, Jan F; Blanz, Julian; Kalwa, Tobias J; Scotti, Norman A; Kubitz, Jens C


    The present study evaluates whether the quality of advanced cardiac life support (ALS) is improved with an interactive prototype assist device. This device consists of an automated external defibrillator linked to a ventilator and provides synchronised visual and acoustic instructions for guidance through the ALS algorithm and assistance for face-mask ventilations. We compared the cardiopulmonary resuscitation (CPR) quality of emergency medical system (EMS) staff members using the study device or standard equipment in a mannequin simulation study with a prospective, controlled, randomised cross-over study design. Main outcome was the effect of the study device compared to the standard equipment and the effect of the number of prior ALS trainings of the EMS staff on the CPR quality. Data were analysed using analyses of covariance (ANCOVA) and binary logistic regression, accounting for the study design. In 106 simulations of 56 two-person rescuer teams, the mean hands-off time was 24.5% with study equipment and 23.5% with standard equipment (Difference 1.0% (95% CI: -0.4 to 2.5%); p = 0.156). With both types of equipment, the hands-off time decreased with an increasing cumulative number of previous CPR trainings (p = 0.042). The study equipment reduced the mean time until administration of adrenaline (epinephrine) by 23 s (p = 0.003) and that of amiodarone by 17 s (p = 0.016). It also increased the mean number of changes in the person doing chest compressions (0.6 per simulation; p trainings, the time intervals in the ALS algorithm until the defibrillations decreased with standard equipment but increased with the study device. EMS staff with limited training in CPR profit from guidance through the ALS algorithm by the study device. However, the study device somehow reduced the ALS quality of well-trained rescuers and thus can only be recommended for ALS provider with limited experience.

  17. Construction of Comprehensive Information Platform of Assistive Device Service on the Basis of Modularity Theory in Shanghai City%基于模块化理论的上海辅助器具服务信息综合平台建设实践

    Institute of Scientific and Technical Information of China (English)

    宋毓; 金荣; 许斌; 朱韫琦; 万少华; 杨吉吉; 汪伟力


    With the development of internet technology, the informationalized service of assistive device for the disabled will become a trend of development. Based on modularity theory, Shanghai has established Comprehensive Information Platform of Assistive Devices by developing over 10 service modules of assistive devices for the disabled such as platform of basic information, platform of 3-dimenstion display of assistive devices, platform of appliance of assistive devices, appliance and assessment system on App, appliance system for assistive devices specially for rehabilitation institutions, net-rent system of assistive device, online supplier management platform,e-commerce platform of assistive device, data analysis platform for the disabled and policy document management platform. By integrating with all these platforms, Shanghai has constructed a new model of“Internet plus”service of assistive device for the disabled, innovating the application procedures, with the disabled applying and experiencing services at home. Also, the new model has informationalized the evaluation process and played a leading role in assistive device service for the disabled.%随着互联网技术的发展,残疾人辅助器具信息化服务成为未来发展方向。基于模块化理论,上海建立了辅助器具服务信息综合平台,开发了基础数据平台、辅助器具3D展示平台、辅助器具申请平台、APP辅助器具申请评估系统、康复机构辅助器具申请系统、辅助器具租赁系统、供应商管理平台、辅助器具电商平台、残疾人数据分析平台及政策文件管理平台等10大残疾人辅助器具服务模块,实现了“互联网+残疾人辅助器具服务”的新模式。该平台的建立创新了辅具申请流程,使残疾人足不出户可以体验和申领辅具,实现了适配评估全程信息化,对国内残疾人辅助器具服务工作发展起到了示范和引领作用。

  18. Use of vacuum-assisted closure device in a disastrous form of abdominal sepsis and stoma site infection: systematic review and report of a case. (United States)

    Popović, Milos; Barisić, Goran; Marković, Velimir; Petrović, Jelena; Krivokapić, Zoran


    Use of Vacuum-Assisted Closure (VAC) for treatment of open abdomen has been established predominantly in cases of severe abdominal trauma, resulting with high percentage of primary fascial closure. The role of VAC technique in cases of severe diffuse peritonitis is not definitely incorrigible. However, in cases of severe complicated abdominal sepsis VAC come up as a last resort.

  19. How Should Pushing Off or the Use of Assistive Devices Be Incorporated in the Timed Up and Go