WorldWideScience

Sample records for biventricular assist device

  1. Cardiac Failure after Liver Transplantation Requiring a Biventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Rita Jermyn

    2014-01-01

    Full Text Available Increased hepatic iron load in extrahepatic organs of cirrhotic patients with and without hereditary hemochromatosis portends a poorer long term prognosis after liver transplant. Hepatic as well as nonhepatic iron overload is associated with increased infectious and postoperative complications, including cardiac dysfunction. In this case report, we describe a cirrhotic patient with alpha 1 antitrypsin deficiency and nonhereditary hemochromatosis (non-HFE that developed cardiogenic shock requiring mechanical circulatory support for twenty days after liver transplant. Upon further investigation, she was found to have significant iron deposition in both the liver and heart biopsies. Her heart regained complete and sustained recovery following ten days of mechanical biventricular support. This case highlights the importance of preoperatively recognizing extrahepatic iron deposition in patients referred for liver transplantation irrespective of etiology of liver disease as this may prevent postoperative complications.

  2. Ventricular assist device

    Science.gov (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

  3. Successful trans-Atlantic air ambulance transfer of a patient supported by a bi-ventricular assist device.

    Science.gov (United States)

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

    2011-08-01

    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.

  4. A new transcutaneous energy transmission system with hybrid energy coils for driving an implantable biventricular assist device.

    Science.gov (United States)

    Okamoto, Eiji; Yamamoto, Yoshiro; Akasaka, Yuhta; Motomura, Tadashi; Mitamura, Yoshinori; Nosé, Yukihiko

    2009-08-01

    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.

  5. Current status of the gyro centrifugal blood pump--development of the permanently implantable centrifugal blood pump as a biventricular assist device (NEDO project).

    Science.gov (United States)

    Nosé, Yukihiko; Furukawa, Kojiro

    2004-10-01

    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.

  6. Anastomose cavo-pulmonar associada ao suporte circulatório esquerdo comparada à assistência biventricular na falência cardíaca aguda Cavo-pulmonary anastomosis associated with left ventricular in comparison with biventricular circulatory support in acute heart failure

    Directory of Open Access Journals (Sweden)

    Luis Alberto Saraiva Santos

    2012-12-01

    Full Text Available OBJETIVO: Este estudo avaliou o desempenho hemodinâmico e as alterações miocárdicas decorrentes do emprego de dispositivos de assistência ventricular esquerda (DAVE, associado ou não à descompressão do ventrículo direito por meio de derivação cavo-pulmonar, sendo esses achados comparados ao emprego de assistência circulatória biventricular. MÉTODOS: Vinte e um suínos foram submetidos à indução de insuficiência cardíaca através de fibrilação ventricular, sendo a atividade circulatória mantida por DAVE durante 180 minutos. No grupo controle, foi apenas implantado o DAVE. No grupo derivação, além do DAVE foi realizada cirurgia de derivação cavo-pulmonar. No grupo biventricular, foi instituída assistência biventricular. Foram monitoradas as pressões intracavitárias por 3 horas de assistência e amostras do endocárdio dos dois ventrículos foram coletadas e analisadas à microscopia óptica e eletrônica. RESULTADOS: O lactato sérico foi significativamente menor no grupo biventricular (P=0,014. A diferença observada entre o fluxo do DAVE nos grupos derivação e controle (+55±14 ml/kg/min, P=0,072 não foi significativa, enquanto que o fluxo no grupo biventricular foi significativamente maior (+93±17 ml/kg/min, P=0,012 e se manteve estável durante o experimento. A pressão arterial média (PAM se manteve constante apenas no grupo biventricular (POBJECTIVE: Right ventricular (RV failure during left ventricular assist device (LVAD support can result in severe hemodynamic compromise with high mortality. This study investigated the acute effects of cavo-pulmonary anastomosis on LVAD performance and RV myocardial compromise in comparison with biventricular circulatory support, in a model of biventricular failure. METHODS: LVAD support was performed by centrifugal pump in 21 pigs with severe biventricular failure obtained by FV induction. Animals were randomized to be submitted to cavo-pulmonary anastomosis, to

  7. Biventricular Finite Element Modeling of the Acorn CorCap Cardiac Support Device on a Failing Heart

    OpenAIRE

    Wenk, JF; L. Ge; Zhang, Z; Mojsejenko, D; Potter, DD; Tseng, EE; Guccione, JM; Ratcliffe, MB

    2013-01-01

    Background: The Acorn CorCap Cardiac Support Device (CSD; Acorn Cardiovascular Inc, St. Paul, MN) is a woven polyester jacket that is placed around the heart and designed to reverse the progressive remodeling associated with dilated cardiomyopathy. However, the effects of the Acorn CSD on myofiber stress and ventricular function remain unknown. We tested the hypothesis that the Acorn CSD reduces end-diastolic (ED) myofiber stress. Methods: A previously described weakly coupled biventricular f...

  8. Ventricular assist device in univentricular heart physiology.

    Science.gov (United States)

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

    2013-04-01

    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.

  9. HeartWare HVAD for Biventricular Support in Children and Adolescents: The Stanford Experience.

    Science.gov (United States)

    Stein, Mary Lyn; Yeh, Justin; Reinhartz, Olaf; Rosenthal, David N; Kaufman, Beth D; Almond, Chris S; Hollander, Seth A; Maeda, Katsuhide

    2016-01-01

    Despite increasing use of mechanical circulatory support in children, experience with biventricular device implantation remains limited. We describe our experience using the HeartWare HVAD to provide biventricular support to three patients and compare these patients with five patients supported with HeartWare left ventricular assist device (LVAD). At the end of the study period, all three biventricular assist device (BiVAD) patients had been transplanted and were alive. LVAD patients were out of bed and ambulating a median of 10.5 days postimplantation. The BiVAD patients were out of bed a median of 31 days postimplantation. Pediatric patients with both left ventricular and biventricular heart failure can be successfully bridged to transplantation with the HeartWare HVAD. Rapid improvement in functional status following HVAD implantation for isolated left ventricular support is seen. Patients supported with BiVAD also demonstrate functional recovery, albeit more modestly. In the absence of infection, systemic inflammatory response raises concern for inadequate support. PMID:26919182

  10. MECHANISMS OF RIGHT VENTRICULAR FAILURE AND BIVENTRICULAR MECHANICAL CIRCULATORY SUPPORT

    Directory of Open Access Journals (Sweden)

    G. P. Itkin

    2013-01-01

    Full Text Available The paper presents a review of the problems of mechanical circulatory support with left ventricular bypass in total cardiac failure. Dysfunction of right ventricular defines the high mortality on left ventricular device. One of the effective methods for solving this problem is the use of right ventricular assisted devices. There are considered of the basic physiological mechanisms of interaction between the right and left ventricles of the heart, affecting on the function of the right heart. Shows the need to assess right ventricular function before deciding on mechanical circulatory support. Provides examples of the estimation the predictors of the right ventricular failure. The basic methods and devices of biventricular circulatory support were con- sidered. 

  11. Biventricular Takotsubo Cardiomyopathy

    Science.gov (United States)

    Daoko, Joseph; Rajachandran, Manu; Savarese, Ronald; Orme, Joseph

    2013-01-01

    Biventricular takotsubo cardiomyopathy is associated with more hemodynamic instability than is isolated left ventricular takotsubo cardiomyopathy; medical management is more invasive and the course of hospitalization is longer. In March 2011, a 62-year-old woman presented at our emergency department with abdominal pain, nausea, and vomiting. On hospital day 2, she experienced chest pain. An electrocardiogram and cardiac enzyme levels suggested an acute myocardial infarction. She underwent cardiac angiography and was found to have severe left ventricular systolic dysfunction involving the mid and apical segments, which resulted in a left ventricular ejection fraction of 0.10 to 0.15 in the absence of obstructive coronary artery disease. Her hospital course was complicated by cardiogenic shock that required hemodynamic support with an intra-aortic balloon pump and dobutamine. A transthoracic echocardiogram revealed akinesis of the mid-to-distal segments of the left ventricle and mid-to-apical dyskinesis of the right ventricular free wall characteristic of biventricular takotsubo cardiomyopathy. After several days of medical management, the patient was discharged from the hospital in stable condition. To the best of our knowledge, this is the first review of the literature on biventricular takotsubo cardiomyopathy that compares its hemodynamic instability and medical management requirements with those of isolated left ventricular takotsubo cardiomyopathy. Herein, we discuss the case of our patient, review the pertinent medical literature, and convey the prevalence and importance of right ventricular involvement in patients with takotsubo cardiomyopathy. PMID:23914028

  12. Ventricular Septal Perforation after Biventricular Takotsubo Cardiomyopathy Successfully Repaired with an Amplatzer Device: First Report in the Literature

    Directory of Open Access Journals (Sweden)

    Alfredo E. Rodríguez

    2016-01-01

    Full Text Available A 79-year-old female was admitted with sudden onset dyspnea, mild oppressive chest pain, and severe anxiety disorder. Patient had history of hypertension, dyslipidemia, smoking, and chronic obstructive pulmonary disease. On admission blood pressure was 160/90 and heart rate was 130 bpm. Transthoracic echocardiography (TE and contrast tomography showed a thin septum with an abnormal left and right ventricular contraction with an “apical ballooning” pattern and mild increase of cardiac enzymes. At the 4th day of admission, the patient presented symptoms and signs of congestive heart failure and developed cardiogenic shock. EKG showed an inversion of T waves in all precordial leads. In a new TE, a ventricular septal perforation (VSP in the apical portion of the septum was seen. Coronary angiogram showed angiographically “normal” coronary arteries. With a diagnosis of VSP in takotsubo cardiomyopathy, a percutaneous procedure to repair the VSP was performed 11 days after admission. The VSP was closed with an Amplatzer device. TE performed 24 hours after showed significant improvement of ventricular function and good apposition of the Amplatzer device. Three days later she was discharged from the hospital. To our knowledge, this is the first reported case of a VSP in a TCM repaired percutaneously with an occluder device.

  13. Mechanical circulatory assist devices: a primer for critical care and emergency physicians.

    Science.gov (United States)

    Sen, Ayan; Larson, Joel S; Kashani, Kianoush B; Libricz, Stacy L; Patel, Bhavesh M; Guru, Pramod K; Alwardt, Cory M; Pajaro, Octavio; Farmer, J Christopher

    2016-01-01

    Mechanical circulatory assist devices are now commonly used in the treatment of severe heart failure as bridges to cardiac transplant, as destination therapy for patients who are not transplant candidates, and as bridges to recovery and "decision-making". These devices, which can be used to support the left or right ventricles or both, restore circulation to the tissues, thereby improving organ function. Left ventricular assist devices (LVADs) are the most common support devices. To care for patients with these devices, health care providers in emergency departments (EDs) and intensive care units (ICUs) need to understand the physiology of the devices, the vocabulary of mechanical support, the types of complications patients may have, diagnostic techniques, and decision-making regarding treatment. Patients with LVADs who come to the ED or are admitted to the ICU usually have nonspecific clinical symptoms, most commonly shortness of breath, hypotension, anemia, chest pain, syncope, hemoptysis, gastrointestinal bleeding, jaundice, fever, oliguria and hematuria, altered mental status, headache, seizure, and back pain. Other patients are seen for cardiac arrest, psychiatric issues, sequelae of noncardiac surgery, and trauma. Although most patients have LVADs, some may have biventricular support devices or total artificial hearts. Involving a team of cardiac surgeons, perfusion experts, and heart-failure physicians, as well as ED and ICU physicians and nurses, is critical for managing treatment for these patients and for successful outcomes. This review is designed for critical care providers who may be the first to see these patients in the ED or ICU. PMID:27342573

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

    Directory of Open Access Journals (Sweden)

    Droogan Christopher

    2010-12-01

    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.

  15. Update on ventricular assist device technology.

    Science.gov (United States)

    Stahl, Mary A; Richards, Nancy M

    2009-01-01

    Ventricular assist devices are an important component in the arsenal of therapies to support the failing heart. This article provides an update on the variety of pulsatile, centrifugal, and axial-flow devices available in the United States. Common indications such as Bridge to Recovery and Bridge to Transplant are explored, as are the emerging indications Destination Therapy, Bridge to Decision, and Bridge to Bridge. Ventricular assist devices as support during high-risk percutaneous coronary intervention and the devices that can be rapidly deployed for this support are included. Clinical aspects of patient care including common complications, psychosocial concerns, and ethical considerations are reviewed. PMID:19174634

  16. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Science.gov (United States)

    2010-04-01

    ... 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...

  17. Cerebrovascular complications of left ventricular assist devices

    NARCIS (Netherlands)

    Backes, Daan; van den Bergh, Walter M; van Duijn, Abram L; Lahpor, Jaap R; van Dijk, Diederik; Slooter, Arjen J C

    2012-01-01

    Left ventricular assist devices (LVADs) are increasingly being used as a bridge to heart transplantation or destination therapy. It is unclear which antithrombotic regimen should be used to reduce the risk of stroke. We systematically reviewed the literature on all types of antithrombotic regimens a

  18. CT of left ventricular assist devices.

    Science.gov (United States)

    Carr, Carrie M; Jacob, Jaisy; Park, Soon J; Karon, Barry L; Williamson, Eric E; Araoz, Philip A

    2010-03-01

    Left ventricular assist devices (LVADs) have become an increasingly beneficial option for patients with heart failure, especially in light of the insufficient availability of donor hearts. LVADs have been used effectively in end-stage heart failure as a bridge to heart transplantation, as destination therapy for those ineligible for transplantation, or as a bridge to myocardial recovery. Presently, a wide variety of LVADs are being used therapeutically. Four different LVADs have been used at the authors' institution. The records of 42 patients who underwent implantation of 46 total LVADs during a 17-month period were reviewed; in 23 of these patients, computed tomography of the device was performed. Increased use of LVADs necessitates understanding of the normal positioning of a variety of these devices and recognition of potential complications, which include inflow and outflow cannula complications, postoperative hemorrhage, pericardial tamponade, thrombus formation, aortic valve stenosis, aortic valve insufficiency, right-sided heart failure, and infection. PMID:20228327

  19. Predictors of right ventricular failure after left ventricular assist device implantation.

    Science.gov (United States)

    Koprivanac, Marijan; Kelava, Marta; Sirić, Franjo; Cruz, Vincent B; Moazami, Nader; Mihaljević, Tomislav

    2014-12-01

    Number of left ventricular assist device (LVAD) implantations increases every year, particularly LVADs for destination therapy (DT). Right ventricular failure (RVF) has been recognized as a serious complication of LVAD implantation. Reported incidence of RVF after LVAD ranges from 6% to 44%, varying mostly due to differences in RVF definition, different types of LVADs, and differences in patient populations included in studies. RVF complicating LVAD implantation is associated with worse postoperative mortality and morbidity including worse end-organ function, longer hospital length of stay, and lower success of bridge to transplant (BTT) therapy. Importance of RVF and its predictors in a setting of LVAD implantation has been recognized early, as evidenced by abundant number of attempts to identify independent risk factors and develop RVF predictor scores with a common purpose to improve patient selection and outcomes by recognizing potential need for biventricular assist device (BiVAD) at the time of LVAD implantation. The aim of this article is to review and summarize current body of knowledge on risk factors and prediction scores of RVF after LVAD implantation. Despite abundance of studies and proposed risk scores for RVF following LVAD, certain common limitations make their implementation and clinical usefulness questionable. Regardless, value of these studies lies in providing information on potential key predictors for RVF that can be taken into account in clinical decision making. Further investigation of current predictors and existing scores as well as new studies involving larger patient populations and more sophisticated statistical prediction models are necessary. Additionally, a short description of our empirical institutional approach to management of RVF following LVAD implantation is provided. PMID:25559829

  20. The Flow Field Inside Ventricle Assist Device

    Science.gov (United States)

    Einav, Shmuel; Rosenfeld, Moshe; Avrahami, Idit

    2000-11-01

    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.

  1. 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)

    2005-03-01

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

  2. The medical physics of ventricular assist devices

    International Nuclear Information System (INIS)

    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

  3. Assistive Device for Efficient Intravitreal Injections.

    Science.gov (United States)

    Ullrich, Franziska; Michels, Stephan; Lehmann, Daniel; Pieters, Roel S; Becker, Matthias; Nelson, Bradley J

    2016-08-01

    Intravitreal therapy is the most common treatment for many chronic ophthalmic diseases, such as age-related macular degeneration. Due to the increasing worldwide demand for intravitreal injections, there exists a need to render this medical procedure more time- and cost-efficient while increasing patient safety. The authors propose a medical assistive device that injects medication intravitreally. Compared to the manual intravitreal injection procedure, an automated device has the potential to increase safety for patients, decrease procedure times, allow for integrated data storage and documentation, and reduce costs for medical staff and expensive operating rooms. This work demonstrates the development of an assistive injection system that is coarsely positioned over the patient's head by the human operator, followed by automatic fine positioning and intravitreal injection through the pars plana. Several safety features, such as continuous eye tracking and iris recognition, have been implemented. The functioning system is demonstrated through ex vivo experiments with porcine eyes. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:752-762.]. PMID:27548453

  4. Biventricular Mural Endocarditis on the Intraventricular Septum.

    Science.gov (United States)

    Mori, Makoto; Hosoba, Soh; Yoshimura, Stephanie; Lattouf, Omar

    2015-10-28

    Mural endocarditis is an inflammation and disruption of the nonvalvular endocardial surface of the cardiac chambers. We present a rare case of mural endocarditis on the intraventricular (IV) septum on both the left and right ventricular side with intact valvular annulus. This case highlights the complexity of the operative and postoperative management in an unprecedented case of biventricular mural endocarditis.

  5. Experience with the Sarns centrifugal pump as a ventricular assist device.

    Science.gov (United States)

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

    1990-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Diego Arroyo

    2011-01-01

    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.

  7. 47 CFR 74.870 - Wireless video assist devices.

    Science.gov (United States)

    2010-10-01

    ... km of a television broadcasting station, including Class A television stations, low power television... Stations § 74.870 Wireless video assist devices. Television broadcast auxiliary licensees and motion picture and television producers, as defined in § 74.801 may operate wireless video assist devices on...

  8. 34 CFR 300.5 - Assistive technology device.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Assistive technology device. 300.5 Section 300.5 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION...

  9. Costs and Outcomes in the Care of Bi-ventricular Support as a Bridge to Cardiac Transplant.

    Science.gov (United States)

    Swartz, Michael F; Angona, Ron; Smith, Karen; Kraenzlin, Franca; Stypula, Christine M; Joshi, Devang; Tchantchaleishvili, Vakhtang; Hicks, George L; Massey, H Todd

    2016-01-01

    Bi-ventricular (Bi-V) mechanical circulatory support is commonly used as a bridge to cardiac transplant. However, the optimal strategy is unknown. We examined the outcomes, as well as the costs in the use of Bi-V support as a bridge to cardiac transplant. From 2001 to 2014, three different Bi-V support strategies were utilized: 1) Para-corporeal ventricular assist device (PVAD-2001-2006), 2) Heartmate II left ventricular assist device in conjunction with a temporary CentriMag right ventricular assist device (HMII + CMAG-2006-2012), and the total artificial heart (TAH-2012-2014). Total costs were derived from the hospitalization at implant, and postimplant costs defined as equipment and re-hospitalizations before transplantation. Sixty-five (34 PVADs, 20 HMII + CMAG, and 11 TAHs) devices were used as a bridge for transplant. There were no differences in implant variables including age, INTERMACS score, or implant length of stay. Although the wait list mortality was not different between groups (PVAD-32%, HMII + CMAG-45%, TAH-54%; p = 0.3), the percentage of patients transplanted were highest in the PVAD group: (PVAD-55.8%, HMII + CMAG-30.0%, TAH-18.2%; p = 0.01). Total costs were not significantly different between groups (PVAD-$306,166 ± 247,839, HMII + CMAG-$278,958 ± 135,324, TAH-$321,387 ± 21,2477; p = 0.5). Despite variations in therapy, outcomes and costs for patients requiring Bi-V support as a bridge to cardiac transplant have remained constant. PMID:27258229

  10. Fluid dynamics of heart assist device

    Science.gov (United States)

    Jones, R. T.

    1976-01-01

    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.

  11. Human Grasp Assist Device With Exoskeleton

    Science.gov (United States)

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

    2014-01-01

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

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

    OpenAIRE

    Hiriyur Shivalingappa Jayanthkumar; Chinnamuthu Murugesan; John Rajkumar; Bandlapally Ramanjaneya Gupta Harish; Kanchi Muralidhar

    2013-01-01

    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 ca...

  13. Laser-assisted manufacturing of thermal energy devices

    Science.gov (United States)

    Zhang, Tao; Tewolde, Mahder; Kim, Ki-Hoon; Seo, Dong-Min; Longtin, Jon P.; Hwang, David J.

    2016-03-01

    In this study, we will present recent progress in the laser-assisted manufacturing of thermal energy devices that require suppressed thermal transport characteristics yet maintaining other functionalities such as electronic transport or mechanical strength. Examples of such devices to be demonstrated include thermoelectric generator or insulating materials. To this end, it will be shown that an additive manufacturing approaches can be facilitated and improved by unique processing capabilities of lasers in composite level. In order to tailor thermal characteristics in thermal devices, we will mainly investigate the potential of laser heating, curing, selective removal and sintering processes of material systems in the composite level.

  14. Vocational Reintegration of Handicapped Workers with Assistive Devices

    Science.gov (United States)

    Cooper, N. E.

    1977-01-01

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

  15. THE PUCA PUMP - A LEFT-VENTRICULAR ASSIST DEVICE

    NARCIS (Netherlands)

    VERKERKE, B; DEMUINCK, ED; RAKHORST, G; BLANKSMA, PK

    1993-01-01

    Left ventricular assist devices (LVADs) that are being used clinically still have specific drawbacks. Therefore, a new concept for mechanical circulatory support was developed, the pulsatile catheter (PUCA) pump. It consists of an extracorporeally placed, pneumatically driven membrane pump that is c

  16. Laparoscopic repair of diaphragmatic hernia after left ventricular assist device.

    Science.gov (United States)

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

    2003-06-01

    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.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...

  18. Towards the development of a pediatric ventricular assist device.

    Science.gov (United States)

    Borovetz, Harvey S; Badylak, Stephen; Boston, J Robert; Johnson, Carl; Kormos, Robert; Kameneva, Marina V; Simaan, Marwan; Snyder, Trevor A; Tsukui, Hiro; Wagner, William R; Woolley, Joshua; Antaki, James; Diao, Chenguang; Vandenberghe, Stijn; Keller, Bradley; Morell, Victor; Wearden, Peter; Webber, Steven; Gardiner, Jeff; Li, Chung M; Paden, Dave; Paden, Bradley; Snyder, Shaun; Wu, Jingchun; Bearnson, Gill; Hawkins, John A; Jacobs, Gordon; Kirk, John; Khanwilkar, Pratap; Kouretas, Peter C; Long, James; Shaddy, R E

    2006-01-01

    The very limited options available to treat ventricular failure in children with congenital and acquired heart diseases have motivated the development of a pediatric ventricular assist device at the University of Pittsburgh (UoP) and University of Pittsburgh Medical Center (UPMC). Our effort involves a consortium consisting of UoP, Children's Hospital of Pittsburgh (CHP), Carnegie Mellon University, World Heart Corporation, and LaunchPoint Technologies, Inc. The overall aim of our program is to develop a highly reliable, biocompatible ventricular assist device (VAD) for chronic support (6 months) of the unique and high-risk population of children between 3 and 15 kg (patients from birth to 2 years of age). The innovative pediatric ventricular assist device we are developing is based on a miniature mixed flow turbodynamic pump featuring magnetic levitation, to assure minimal blood trauma and risk of thrombosis. This review article discusses the limitations of current pediatric cardiac assist treatment options and the work to date by our consortium toward the development of a pediatric VAD.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    -defibrillator device with data available on biventricular pacing percentage and pre-implantation 24-h Holter recordings were included. Using logistic regression, we estimated the influence of ectopic beats on the percentage of biventricular pacing. Reverse remodeling was measured as reductions in atrial and left...... ventricular end-systolic volumes (LVESV) at 1 year. Cox models were used to assess the influence of ectopic beats on the outcomes of heart failure (HF) or death, ventricular tachyarrhythmias (VTAs), and death. RESULTS: In the pre-implantation Holter recording, ectopic beats accounted for a mean 3.2 ± 5...... biventricular pacing (Holter monitoring of patients selected for CRT for optimal outcome. (MADIT-CRT: Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization...

  20. Design optimization of field-plate assisted RESURF devices

    OpenAIRE

    Boksteen, B.K.; A. Ferrara; Heringa, A.; Steeneken, P. G.; Koops, G.E.J.; Hueting, R.J.E.

    2013-01-01

    A mathematical model for optimizing the 2-D potential distribution in the drift region of field-plate (FP)-assisted RESURF devices (Fig. 1) is presented. The proposed model extends earlier work [1-2] by including top-bottom dielectric asymmetry (typical in SOI devices [3]), non-zero field plate potentials VFP and grading of design parameters other than drift region doping. This generally-applicable, TCAD-verified [4], model provides a guideline for optimizing the drain extension in a wide ran...

  1. Development of a New Pulsatile Ventricular Assist Device

    OpenAIRE

    Kurosaki, Tatsuya; Sakai, Hiroshi; Ninomiya, Shinji; Fukunaga, Shintaro; Sueda, Taijiro

    2006-01-01

    We developed a small, lightweight, low-cost implantable ventricular assist device (VAD) for use in smaller Japanese subjects. The major advantage of this pump is the simplicity of its fabrication. Most parts of the pump were shaped from a transparent acrylic block by a turning process, and the diaphragm was made from a silicon sheet. Since this method of construction did not require any complex processes, we could manufacture many pumps of various shapes. We determined the most efficient shap...

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

    DEFF Research Database (Denmark)

    Boissy, Patrice; Hester, Todd; Sherrill, Delsey;

    2007-01-01

    Mobility assistive devices (MAD) such as canes can improve mobility and allow independence in the performance of mobility-related tasks. The use of MAD is often prescribed for stroke survivors. Despite their acknowledged qualities, MAD in real life conditions are typically underutilized, misused ...... accelerometers, gyroscopes, and a load cell to identify the task a patient was performing and examine the use of the cane in the context of the task....

  3. Cooperative Indoor Navigation Using Environment-Embedded Assistance Devices

    OpenAIRE

    Suzuki, Tsuyoshi; Kawabata, Kuniaki; Kurabayashi, Daisuke; Paromtchik, Igor E.; Asama, Hajime

    2008-01-01

    This chapter introduced a cooperative navigation strategy for mobile robots operating in indoor environments with the embedded Information Assistant and Optical Pointer devices, as an application of an intelligent environmental robotic system. In order to provide a more flexible navigation, the management of environmental information was considered. The static global information supplies topological details such as the positional relation of any starting point to any goal point in order to cr...

  4. What Are Some Types of Assistive Devices and How Are They Used?

    Science.gov (United States)

    ... on Assistive Devices for People with Hearing, Voice, Speech, or Language Disorders . PBS Parents provides examples of assistive devices as well as some specific guidance on alternative communication strategies for people who struggle to produce or comprehend spoken ...

  5. Postcardiotomy centrifugal assist: a single surgeon's experience.

    Science.gov (United States)

    Curtis, Jack J; McKenney-Knox, Charlotte A; Wagner-Mann, Colette C

    2002-11-01

    Because of the infrequent application of cardiac assist devices for postcardiotomy heart failure, most published reports include the results of learning curves from multiple surgeons. Between October 1986 and June 2001, a single surgeon used 35 Sarns Centrifugal Pumps as ventricular assist devices in 21 patients with severe hemodynamic compromise after open heart surgery (0.88% incidence). Patients' ages ranged from 39 to 77 (mean, 59.6 years). Three patients required right ventricular assist devices, 4 left ventricular assist devices, and 14 had biventricular assist devices. For all, the indication for application was inability to wean from cardiopulmonary bypass despite multiple inotropes and intraaortic balloon pumping. All were expected to be intraoperative deaths without further mechanical assistance. Patients were assisted from 2 to 434 h (median, 48 h). Fifteen patients (71.4%) were weaned from device(s), and 11 patients (52.4%) were hospital survivors. Actuarial survival in those dismissed from the hospital was 78% at 5 years and 39% at 10 years. Patients facing certain demise after cardiac surgery can be salvaged with temporary centrifugal mechanical assist. Results are competitive with that achieved with more sophisticated devices. Hospital survivors enjoy reasonable longevity.

  6. Specification of supervisory control systems for ventricular assist devices.

    Science.gov (United States)

    Cavalheiro, André C M; Santos Fo, Diolino J; Andrade, Aron; Cardoso, José Roberto; Horikawa, Osvaldo; Bock, Eduardo; Fonseca, Jeison

    2011-05-01

    One of the most important recent improvements in cardiology is the use of ventricular assist devices (VADs) to help patients with severe heart diseases, especially when they are indicated to heart transplantation. The Institute Dante Pazzanese of Cardiology has been developing an implantable centrifugal blood pump that will be able to help a sick human heart to keep blood flow and pressure at physiological levels. This device will be used as a totally or partially implantable VAD. Therefore, an improvement on device performance is important for the betterment of the level of interaction with patient's behavior or conditions. But some failures may occur if the device's pumping control does not follow the changes in patient's behavior or conditions. The VAD control system must consider tolerance to faults and have a dynamic adaptation according to patient's cardiovascular system changes, and also must attend to changes in patient conditions, behavior, or comportments. This work proposes an application of the mechatronic approach to this class of devices based on advanced techniques for control, instrumentation, and automation to define a method for developing a hierarchical supervisory control system that is able to perform VAD control dynamically, automatically, and securely. For this methodology, we used concepts based on Bayesian network for patients' diagnoses, Petri nets to generate a VAD control algorithm, and Safety Instrumented Systems to ensure VAD system security. Applying these concepts, a VAD control system is being built for method effectiveness confirmation. PMID:21595713

  7. Defining pulsatility during continuous-flow ventricular assist device support.

    Science.gov (United States)

    Soucy, Kevin G; Koenig, Steven C; Giridharan, Guruprasad A; Sobieski, Michael A; Slaughter, Mark S

    2013-06-01

    Continuous-flow ventricular assist devices (CVADs) have gained widespread use as an effective clinical therapy for patients with advanced-stage heart failure. Axial and centrifugal CVADs have been successfully used as bridge-to-transplant and destination therapy. CVADs are smaller, more reliable, and less complex than the first-generation pulsatile-flow ventricular assist devices. Despite their recent clinical success, arteriovenous malformations, gastrointestinal bleeding, hemorrhagic strokes, aortic valve insufficiency, and valve fusion have been reported in heart failure patients supported by CVADs. It has been hypothesized that diminished arterial pressure and flow pulsatility delivered by CVAD may be a contributing factor to these adverse events. Subsequently, the clinical significance of vascular pulsatility continues to be highly debated. Studies comparing pulsatile-flow and continuous-flow support have presented conflicting findings, largely due to variations in device operation, support duration, and the criteria used to quantify pulsatility. Traditional measurements of pulse pressure and pulsatility index are less effective at quantifying pulsatility for mechanically derived flows, particularly with the growing trend of CVAD speed modulation to achieve various pulsatile flow patterns. Kinetic measurements of energy equivalent pressure and surplus hemodynamic energy can better quantify pulsatile energies, yet technologic and conceptual challenges are impeding their clinical adaption. A review of methods for quantifying vascular pulsatility and their application as a research tool for investigating physiologic responses to CVAD support are presented. PMID:23540401

  8. Current Trends in Implantable Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Jens Garbade

    2011-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Demetris Yannopoulos

    2007-01-01

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

    DEFF Research Database (Denmark)

    Pratas, Nuno; Popovski, Petar

    2015-01-01

    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...... announces its interest in establishing a D2D connection) or monitor (which listens for the transmissions from the announcers). Traditionally, the announcers transmit their messages over dedicated channel resources. In contrast, inspired by recent advances on receivers with multiuser decoding capabilities...

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

    Directory of Open Access Journals (Sweden)

    Eduardo Castillejo

    2014-03-01

    Full Text Available 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.

  12. Simulating Pediatric Ventricular Assist Device Operation Using Fluid Structure Interaction

    Science.gov (United States)

    Long, Chris; Bazilevs, Yuri; Marsden, Alison

    2012-11-01

    Ventricular Assist Devices (VADs) provide mechanical circulatory support to patients in heart failure. They are primarily used to extend life until cardiac transplant, but also show promise as a ``bridge-to-recovery'' device in pediatric patients. Commercially available pediatric pumps are pulsatile displacement pumps, with two distinct chambers for air and blood separated by a thin, flexible membrane. The air chamber pneumatically drives the membrane, which drives blood through the other chamber via displacement. The primary risk factor associated with these devices is stroke or embolism due to thrombogenesis in the blood chamber, occurring in as many as 40% of patients. Our goal is to perform simulations that accurately model the hemodynamics of the device, as well as the non-linear membrane buckling. We apply a finite-element based fluid solver, with an Arbitrary Lagrangian-Eulerian (ALE) framework to account for mesh motion. Isogeometric Analysis with a Kirchhoff-Love shell formulation is used on the membrane, and two distinct fluid subdomains are used for the air and blood chambers. The Fluid Structure Interaction (FSI) problem is solved simultaneously, using a Matrix Free method to model the interactions at the fluid-structure boundary. Methods and results are presented.

  13. Minimally Invasive Treatment of Biventricular Hydrocephalus Caused by a Giant Basilar Apex Aneurysm via a Staged Combination of Endoscopy and Endovascular Embolization: A Case Report.

    Science.gov (United States)

    Setty, Pradeep; Volkov, Andrey; Richards, Boyd; Barrett, Ryan

    2015-01-01

    Biventricular hydrocephalus caused by a Giant Basilar Apex Aneurysm (GBAA) is a rare finding that presents unique and challenging treatment decisions. We report a case of GBAA causing a life-threatening biventricular hydrocephalus in which both the aneurysm and hydrocephalus were given definitive treatment through a staged, minimally invasive approach. An obtunded 82-year-old male was found to have biventricular hydrocephalus caused by an unruptured GBAA obstructing the foramina of Monro. The patient was treated via staged, minimally invasive technique that first involved endoscopic fenestration of the septum pellucidum to create communication between the lateral ventricles. A programmable ventriculo-peritoneal shunt was then placed with a high-pressure setting. The patient was then loaded with dual anti-platelet therapy prior to undergoing endovascular coiling of the GBAA with adjacent stenting of the Posterior Cerebral Artery. He remained on dual anti-platelet therapy and the shunt setting was lowered at the bedside to treat the hydrocephalus. At 6-month follow up, the patient had returned to his cognitive baseline, speaking fluently and appropriately. Biventricular hydrocephalus caused by a GBAA can successfully be treated in a minimally invasive fashion utilizing a combination of endoscopy and endovascular therapy, even when a stent-assisted coiling is needed.

  14. Fluid Structure Interaction Simulations of Pediatric Ventricular Assist Device Operation

    Science.gov (United States)

    Long, Chris; Marsden, Alison; Bazilevs, Yuri

    2011-11-01

    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

    2016-08-01

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

  16. Hemodynamic aspects of biventricular pacing in heart failure

    OpenAIRE

    Ståhlberg, Marcus

    2010-01-01

    Background and aims Biventricular pacing or cardiac resynchronization therapy (CRT) is an established treatment option for selected heart failure (HF) patients. We aimed at evaluating acute and longer-term hemodynamic effects of different pacemaker programmings in CRT patients. For the latter purpose, 10 CRT patients also received an implantable hemodynamic monitor (IHM), allowing for long-term hemodynamic monitoring during ambulatory periods. Study I The hemodynamic ...

  17. Molar distalization with the assistance of Temporary Anchorage Devices.

    Science.gov (United States)

    Palencar, Adrian J

    2015-01-01

    This article describes efficient techniques for distalization of maxillary and mandibular molars with the assistance of Temporary Anchorage Devices (TADs). There are numerous occasions where the distalization of molars is required in lieu of the odontectomy of bicuspids. In the past, extra-oral force has been used, (i.e. Cervical or Combination Head Gear, or intra-oral force, i.e. Posterior Sagittal Appliance, Modified Greenfield Appliance, Williams DMJ 20001, CD Distalizer, Magill Sagittal, Pendulum Appliance, etc.). All the intra-oral appliances have a common denominator the orthodontic clinician has to deal with, the undesirable expression of the Third Law of Newton. The utilization of TADs allows us to circumvent this shortcoming, establishing an absolute anchorage, and thus completely negate the expression of the Third Law of Newton. PMID:25881377

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

    Science.gov (United States)

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

    2014-04-01

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

  19. Biventricular takotsubo cardiomyopathy: case study and review of literature.

    Science.gov (United States)

    Daoko, Joseph; Rajachandran, Manu; Savarese, Ronald; Orme, Joseph

    2013-01-01

    Biventricular takotsubo cardiomyopathy is associated with more hemodynamic instability than is isolated left ventricular takotsubo cardiomyopathy; medical management is more invasive and the course of hospitalization is longer. In March 2011, a 62-year-old woman presented at our emergency department with abdominal pain, nausea, and vomiting. On hospital day 2, she experienced chest pain. An electrocardiogram and cardiac enzyme levels suggested an acute myocardial infarction. She underwent cardiac angiography and was found to have severe left ventricular systolic dysfunction involving the mid and apical segments, which resulted in a left ventricular ejection fraction of 0.10 to 0.15 in the absence of obstructive coronary artery disease. Her hospital course was complicated by cardiogenic shock that required hemodynamic support with an intra-aortic balloon pump and dobutamine. A transthoracic echocardiogram revealed akinesis of the mid-to-distal segments of the left ventricle and mid-to-apical dyskinesis of the right ventricular free wall characteristic of biventricular takotsubo cardiomyopathy. After several days of medical management, the patient was discharged from the hospital in stable condition. To the best of our knowledge, this is the first review of the literature on biventricular takotsubo cardiomyopathy that compares its hemodynamic instability and medical management requirements with those of isolated left ventricular takotsubo cardiomyopathy. Herein, we discuss the case of our patient, review the pertinent medical literature, and convey the prevalence and importance of right ventricular involvement in patients with takotsubo cardiomyopathy.

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

    Directory of Open Access Journals (Sweden)

    Hiriyur Shivalingappa Jayanthkumar

    2013-01-01

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

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

    Science.gov (United States)

    Jayanthkumar, Hiriyur Shivalingappa; Murugesan, Chinnamuthu; Rajkumar, John; Harish, Bandlapally Ramanjaneya Gupta; Muralidhar, Kanchi

    2013-01-01

    Perioperative anaesthetic management of the VentrAssist™ 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. PMID:23716768

  2. Comparison of permanent left ventricular and biventricular pacing in patients with heart failure and chronic atrial fibrillation: prospective haemodynamic study

    OpenAIRE

    Garrigue, S; Bordachar, P.; Reuter, S.; Jaïs, P.; Kobeissi, A; Gaggini, G; Haïssaguerre, M; Clementy, J

    2002-01-01

    Objective: To compare clinical and haemodynamic variables between left ventricular and biventricular pacing in patients with severe heart failure; and to analyse haemodynamic changes during daily life and maximum exercise during chronic left ventricular and biventricular pacing.

  3. Newly developed ventricular assist device with linear oscillatory actuator.

    Science.gov (United States)

    Fukunaga, Kazuyoshi; Funakubo, Akio; Fukui, Yasuhiro

    2003-01-01

    The goal of this study was to develop a new direct electromagnetic left ventricular assist device (DEM-LVAD) with a linear oscillatory actuator (LOA). The DEM-LVAD is a pulsatile pump with a pusher plate. The pusher plate is driven directly by the mover of the LOA. The LOA provides reciprocating motion without using any movement converter such as a roller screw or a hydraulic system. It consists of a stator with a single winding excitation coil and a mover with two permanent magnets. The simple structure of the LOA is based on fewer parts to bring about high reliability and smaller size. The mover moves back and forth when forward and backward electric current is supplied to the excitation coil. The pump housings have been designed using three-dimensional computer aided design software and fabricated with the aid of computer aided manufacturing technology. Monostrut valves (Bjork-Shiley #21) were used for the prototype. The DEM-LVAD dimension is 96 mm in diameter and 50 mm thick with a mass of 0.62 kg and a volume of 280 ml. An in vitro test (afterload 100 mm Hg; preload 10 mm Hg; input power 10 W) demonstrated more than 6 L/minute maximum output and 15% maximum efficiency at 130 beats per minute (bpm). Dynamic stroke volume ranged between 40 and 60 ml. The feasibility of the DEM-LVAD was confirmed. PMID:12790386

  4. The effect of atmospheric pressure on ventricular assist device output.

    Science.gov (United States)

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

    2012-03-01

    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.

  5. Right ventricular failure after left ventricular assist devices.

    Science.gov (United States)

    Lampert, Brent C; Teuteberg, Jeffrey J

    2015-09-01

    Most patients with advanced systolic dysfunction who are assessed for a left ventricular assist device (LVAD) also have some degree of right ventricular (RV) dysfunction. Hence, RV failure (RVF) remains a common complication of LVAD placement. Severe RVF after LVAD implantation is associated with increased peri-operative mortality and length of stay and can lead to coagulopathy, altered drug metabolism, worsening nutritional status, diuretic resistance, and poor quality of life. However, current medical and surgical treatment options for RVF are limited and often result in significant impairments in quality of life. There has been continuing interest in developing risk models for RVF before LVAD implantation. This report reviews the anatomy and physiology of the RV and how it changes in the setting of LVAD support. We will discuss proposed mechanisms and describe biochemical, echocardiographic, and hemodynamic predictors of RVF in LVAD patients. We will describe management strategies for reducing and managing RVF. Finally, we will discuss the increasingly recognized and difficult to manage entity of chronic RVF after LVAD placement and describe opportunities for future research. PMID:26267741

  6. 38 CFR 17.152 - Devices to assist in overcoming the handicap of deafness.

    Science.gov (United States)

    2010-07-01

    ... 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...

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

    NARCIS (Netherlands)

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

    1997-01-01

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

  8. Implantation of a left ventricular assist device in patients with a complex apical anatomy.

    Science.gov (United States)

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

    2012-12-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Parikh M

    2011-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Rady Mohamed Y

    2008-08-01

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

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

    Science.gov (United States)

    Pron, G; Ieraci, L; Kaulback, K

    2012-01-01

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

  12. Preliminary report on the cost effectiveness of ventricular assist devices.

    Science.gov (United States)

    Takura, Tomoyuki; Kyo, Shunei; Ono, Minoru; Tominaga, Ryuji; Miyagawa, Shigeru; Tanoue, Yoshihisa; Sawa, Yoshiki

    2016-03-01

    The aim of the present study was to perform a cost-effectiveness analysis (CEA) of ventricular assist devices (VAD) implantation surgery in the Japanese medical reimbursement system. The study group consisted of thirty-seven patients who had undergone VAD implantation surgery for dilated cardiomyopathy (n = 25; 67.6 %) or hypertrophic cardiomyopathy (n = 4; 10.8 %), and others (n = 8; 21.6 %). Quality-adjusted life years (QALYs) were calculated using the utility score and years of life. Medical reimbursement bills were chosen as cost indices. The observation period was the 12-month period after surgery. Then, the incremental cost-effectiveness ratio was calculated according to the VAD type. In addition, the prognosis after 36 months was estimated on the basis of the results obtained using the Markov chain model. The mean preoperative INTERMACS profile score was 2.35 ± 0.77. Our results showed that the utility score, which indicates the effectiveness of VAD implantation surgery, improved by 0.279 ± 0.188 (ΔQALY, p medical reimbursement bills associated with therapeutic interventions. The calculated result of CEA was 364,501 ± 190,599 (ΔUS$/QALY). The improvement in the utility score was greater for implantable versus extracorporeal VADs (0.233 ± 0.534 vs. 0.371 ± 0.238) and ICER was 303,104 (ΔUS$/ΔQALY). Furthermore, when we estimated CEA for 36 months, the expected baseline value was 102,712 (US$/QALY). Therefore, VAD implantation surgery was cost effective considering the disease specificities. PMID:26242357

  13. Device-Related Thrombosis in Continuous-Flow Left Ventricular Assist Device Support.

    Science.gov (United States)

    Doligalski, Christina Teeter; Jennings, Douglas L

    2016-02-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Sharon Anderson

    2016-04-01

    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.

  15. Simulating Ideal Assistive Devices to Reduce the Metabolic Cost of Running

    Science.gov (United States)

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

    2016-01-01

    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 simtk.org and can provide insight into assistive device design that complements experimental approaches. PMID:27656901

  16. 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

    2012-01-01

    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.

  17. Environmentally-assisted technique for transferring devices onto non-conventional substrates

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chi-Hwan; Kim, Dong Rip; Zheng, Xiaolin

    2016-05-10

    A device fabrication method includes: (1) providing a growth substrate including an oxide layer; (2) forming a metal layer over the oxide layer; (3) forming a stack of device layers over the metal layer; (4) performing fluid-assisted interfacial debonding of the metal layer to separate the stack of device layers and the metal layer from the growth substrate; and (5) affixing the stack of device layers to a target substrate.

  18. Successful treatment with biventricular pacing in a patient with hypertrophic obstructive cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    HE Ji-qiang; JIANG Teng-yong; WANG Yun-long; WANG Yan; L(U) Shu-zheng

    2011-01-01

    We report the effects of biventricular pacing in a patient with hypertrophic obstructive cardiomyopathy (HOCM) refractory to medical therapy. A 58-year-old man with HOCM had suffered from dyspnea,chest pain and palpitation for 5 years. Cardiac catheterization showed a left ventricular outflow tract (LVOT) gradient of 80 mmHg. He refused septal myomectomy and the septal ablation was not available. Based on intraoperative pressure measurements,he was implanted with biventricular pacing and LVOT gradient decreased to 10 mmHg. During the follow-up period of 6 months, the patient's symptoms were markedly improved. Biventricular pacing may be an alternative therapy for patients with HOCM.

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  20. Device for assisting the operation and administration of reactor cores

    International Nuclear Information System (INIS)

    Purpose: To enable even unskilled persons to select adequate control rod planning in the same manner as done by the skilled designers. Constitution: Information showing the state of the reactor core before the control rod operation, for example, the control rod pattern and the power distribution, and the control rod alteration pattern after the control rod operation are inputted into an input device, while data base previously prepared based on the considerations of skilled designers are stored in the data base memory device. The control rod change pattern and the power distribution are inputted by the input device to the adequacy judging device for the control rod relative position and the stored data base are read out to determine the adequacy for the control relative position. The result is outputted to the judging device to display the adequacy. (Sekiya, K.)

  1. 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)

    2001-01-01

    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.

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

    OpenAIRE

    Everett Christopher B; Thomas Bruce W; Moncure Michael

    2012-01-01

    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...

  3. Orthotopic heart transplant versus left ventricular assist device: A national comparison of cost and survival

    Science.gov (United States)

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

    2012-01-01

    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

  4. Large Right Ventricular Clot in Pulmonary Atresia With Intact Ventricular Septum: In Defense of Biventricular Approach.

    Science.gov (United States)

    Dutta, Nilanjan; Ghosh, Rajarshi; Awasthy, Neeraj; Iyer, Parvathi U; Girotra, Sumir; Iyer, Krishna S

    2016-09-01

    Thrombus formation within the right ventricle (RV) in the setting of pulmonary atresia with intact ventricular septum (PAIVS) is not a very common occurrence and can be catastrophic. We present the case of a seven-month-old child with PAIVS and RV clot who successfully underwent biventricular repair. We discuss the interesting case and the rationale for management by means of biventricular repair over single ventricle repair when feasible in such a setting.

  5. [Implantation of a biventricular ICD in a patient with dextrocardia with situs inversus].

    Science.gov (United States)

    Vurgun, Veysel Kutay; Gerede, Menekşe; Altın, Ali Timuçin; Candemir, Başar; Akyürek, Ömer

    2015-01-01

    In order to reduce sudden cardiac death and heart failure symptoms, biventricular implantable cardioverter defibrillator (ICD) implantation is a treatment method commonly used in selected patients with cardiomyopathy. The frequency of dextrocardia in congenital heart defects is approximately 0.4/10000. In this group, the frequency of cardiomyopathy development is rare. In this case report we present a patient with dextrocardia undergoing implantation of biventricular ICD.

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

    OpenAIRE

    L. Martínez-Ramos; L. López-García; F. Rodríguez-Henríquez

    2011-01-01

    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 Ide...

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

    OpenAIRE

    L. Martínez-Ramos; L. López-García; F. Rodríguez-Henríquez

    2011-01-01

    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 Id...

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

    Directory of Open Access Journals (Sweden)

    Qamruddin Salima

    2011-07-01

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

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

    Directory of Open Access Journals (Sweden)

    G. Р. Itkin

    2009-01-01

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

  10. 78 FR 34922 - Definition of Auditory Assistance Device

    Science.gov (United States)

    2013-06-11

    ... production and marketing, and introduce more competition for such devices. The Commission decided that this.... This service is available to licensees of broadcast stations and to broadcast and cable network... receiving antennas, cable television equipment, cordless phones, global positioning system (GPS)...

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

    NARCIS (Netherlands)

    Nagata, S.F.

    2006-01-01

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

  12. 14 CFR 382.121 - What mobility aids and other assistive devices may passengers with a disability bring into the...

    Science.gov (United States)

    2010-01-01

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

  13. Modelling Framework and Assistive Device for Peripheral Intravenous Injections

    Science.gov (United States)

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

    2016-02-01

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

  14. Towards automated assistance for operating home medical devices.

    Science.gov (United States)

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

    2010-01-01

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

  15. Thermal assisted ultrasonic bonding of multilayer polymer microfluidic devices

    International Nuclear Information System (INIS)

    A new approach to fabricating multilayer microfluidic devices of poly(methyl methacrylate) (PMMA) was presented. Substrates were preheated to 20–30 °C lower than glass transition temperature (Tg) of the material by a hot plate. Then low-amplitude ultrasonic vibration was employed to generate facial heat at the interface of the PMMA layers. Two crossover micro-separation channel networks and a micro mixer were integrated in a four-layer microfluidic device using this method. The burst pressure of the bonded channel was more than 0.65 MPa. In order to demonstrate the performance of this technique, as many as 12 PMMA layers with micro-channels were successfully bonded together at one time. The average depth loss ratio of micro-channels was 0.6% and the tensile strength was 0.67 MPa. Multilayer poly(ethylene terephthalate) (PET) and cyclo-olefin polymer (COP) substrates were also successfully bonded. This study provided a potential method for constructing complex channel networks for polymer microfluidic devices

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

    Directory of Open Access Journals (Sweden)

    Maithili Arjunwadkar

    2012-11-01

    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.

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

    OpenAIRE

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

    2009-01-01

    The design and initial test results of a new passively suspended Tesla type LAVD blood pump are described. CFD analysis was used in the design of the pump. Overall size of the prototype device is 50 mm in diameter and 75 mm in length. The pump rotor has a density lower than that of blood and when spinning inside the stator in blood it creates a buoyant centering force that suspends the rotor in the radial direction. The axial magnetic force between the rotor and stator restrain the rotor in t...

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

    Directory of Open Access Journals (Sweden)

    Ishino,Kozo

    1991-10-01

    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.

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

    LENUS (Irish Health Repository)

    Healy, David G

    2012-02-03

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

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

    Science.gov (United States)

    Pazzaglia, Mariella; Molinari, Marco

    2016-03-01

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

  1. Physiological Evaluation of a Wheeled Assistive Device for Load Carriage.

    Science.gov (United States)

    Ketko, Itay; Yanovich, Ran; Plotnik, Meir; Gefen, Amit; Heled, Yuval

    2015-11-01

    Carrying heavy weight imposes high physiological strain on the human body, which can adversely affect physical performance. This is especially important for soldiers whose physical performance level may influence mission completion and survival. Recently, wheel-based devices (WBDs), designed to reduce the load on the soldier, have been suggested as a possible solution. Thus, the aim of this study was to evaluate the physiological effects of a proposed WBD prototype. Ten volunteers performed 3 exercise protocols on a treadmill as follows: without carrying any load, with a military backpack, and with the WBD. While using both modalities, they carried 40% of their body weight. Data acquisition included heart rate, body core temperature, oxygen consumption, and subjective comfort. Postural sway was also measured to evaluate the effect of WBD on standing balance. There were no significant differences between the physiological measures while using both modalities. Subjective comfort evaluation showed that the WBD may be more comfortable, yet it raises difficulty in maintaining balance while walking, as can be explained by the postural sway results. We suggest that the similarity in physiological strain while using the WBD was due to reduced walking efficiency in an attempt to maintain balance. It appears that the WBD may have some biomechanical advantages in reducing the subjective pain and pressure at the shoulder region, a matter that should be further examined together with other biomechanical measures. PMID:26506177

  2. Electronic Spatial Assistance for People with Dementia: Choosing the Right Device

    Directory of Open Access Journals (Sweden)

    Cornelia Schneider

    2014-06-01

    Full Text Available The demographic change and ageing in Europe will lead to a growing number of people suffering from dementia. Consequently, costs for public health will increase because people become more and more reliant on care and gradually lose their independence and mobility. In the case of dementia, remedial measures could be provided by assistive technology to support independent living at home for as long as possible. Current assistance systems are often limited to actively raising an alert (i.e., electronic panic buttons or location tracking. Due to this small range of functions these systems are poorly accepted by the target group. Thus, this paper reports on a selection process for a spatial data collection device allowing the development of a new so-called mobility safeguarding assistance system for people with dementia which combines features of different systems. In particular, the wearability as an everyday object is a key issue when it comes to identifying an adequate gadget for elderly people. The proposed methodology considers user requirements as well as technical requirements when it comes to finding a suitable device. Based on these requirements, several different devices were reviewed and tested in order to find most suitable potential device as part of the selection process. The device selected shows that the proposed process on how to choose the right device performed well.

  3. 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;

    2015-01-01

    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...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2002-03-01

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

  6. Numerical simulation of the influence of a left ventricular assist device on the cardiovascular system

    NARCIS (Netherlands)

    Verkerke, GJ; Geertsema, AA; Mihaylov, D; Blanksma, PK; Rakhorst, G

    2000-01-01

    The PUCA (pulsatile catheter) pump is a left ventricular assist device (LVAD) capable of unloading the left ventricle (LV) and improving coronary flow by providing a counterpulsation effect. If consists of an extracorporeal located membrane pump, coupled to a transarterial catheter that enters the b

  7. Numerical simulation of the pulsating catheter pump : A left ventricular assist device

    NARCIS (Netherlands)

    Verkerke, GJ; Mihaylov, D; Geertsema, AA; Lubbers, J; Rakhorst, G

    1999-01-01

    The pulsating catheter (PUCA) pump, a left ventricular assist device, consists of a hydraulically or pneumatically driven membrane pump, extracorporeally placed and mounted to a valved catheter. The catheter is introduced into an easily accessible artery and positioned with its distal tip in the lef

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    Intelligent speed adaptation (ISA) was tested as an assistive device for drivers with an acquired brain injury (ABI). The study was part of the “Pay as You Speed” project (PAYS) and used the same equipment and technology as the main study (Lahrmann et al., in press-a, in press-b). Two drivers...

  9. 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;

    2010-01-01

    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...

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

    Science.gov (United States)

    Henderson, Stacey; Skelton, Heather; Rosenbaum, Peter

    2008-01-01

    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…

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

    Science.gov (United States)

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

    2016-03-01

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

  12. Use of a Three Dimensional Printed Cardiac Model to Assess Suitability for Biventricular Repair.

    Science.gov (United States)

    Farooqi, Kanwal M; Gonzalez-Lengua, Carlos; Shenoy, Rajesh; Sanz, Javier; Nguyen, Khanh

    2016-05-01

    Three dimensional (3D) printing is rapidly gaining interest in the medical field for use in presurgical planning. We present the case of a seven-year-old boy with double outlet right ventricle who underwent a bidirectional Glenn anastomosis. We used a 3D cardiac model to assess his suitability for a biventricular repair. He underwent a left ventricle-to-aorta baffle with a right ventricle-to-pulmonary artery conduit placement. He did well postoperatively and was discharged home with no evidence of baffle obstruction and good biventricular function. A 3D printed model can provide invaluable intracardiac spatial information in these complex patients.

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

    Directory of Open Access Journals (Sweden)

    Cipriani M

    2014-09-01

    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

  14. Surgical Considerations and Challenges for Bilateral Continuous-Flow Durable Device Implantation.

    Science.gov (United States)

    Maltais, Simon; Womack, Sara; Davis, Mary E; Danter, Matthew R; Kushwaha, Sudhir S; Stulak, John M; Haglund, Nicholas

    2016-01-01

    The concept of biventricular support with durable centrifugal pumps is evolving, and the surgical strategy and best practice guidelines for implantation of right-sided devices are still unknown. We present optimal strategy for bilateral HeartWare continuous-flow ventricular assist device (HVAD) implantation in a series of four patients. Patients were implanted with the HVAD pumps simultaneously or sequentially. This report offers a perspective on surgical considerations such as right ventricular positioning, implications related to potential risks of obstruction from the tricuspid apparatus, the role if any of downsizing the outflow anastomosis, and considerations for speed adjustments. In this series, one patient died on support and three patients experienced pump thrombosis requiring device revision. All other patients survived until orthotopic heart transplantation, although one of these patients died from perioperative complications, 2 days posttransplantation. Surgical management of patients with medically refractory biventricular heart failure remains challenging and associated with a high incidence of pump thrombosis. Best practice guidelines from experts' consensus are still needed to address this challenging population. PMID:26479465

  15. Left ventricular assist device inflow cannula thrombus: characterization with two-dimensional transthoracic echocardiography.

    Science.gov (United States)

    Missov, Emil

    2013-01-01

    Thrombotic complications are inherent to current generation nonpulsatile left ventricular assist devices. The clinical expression of device thrombosis ranges from catastrophic failure to protracted and indolent. We report the case of a 79-year-old patient who received a left ventricular assist device as destination therapy and presented only with vague clinical symptoms. He was found to have a large thrombus in close proximity with the inflow cannula at the left ventricular apex, raising the question of mechanical obstruction. We describe the step-by-step contrast-enhanced two-dimensional transthoracic echocardiographic examination which allowed to obtain diagnostic acoustic tomograms of the inflow cannula and obviated the need for any additional imaging modalities. Transthoracic echocardiography (TTE) is the most common imaging modality used in the clinical follow-up of left ventricular assist device recipients. A frequent clinical indication for TTE is to exclude left ventricular apical thrombus near the inflow cannula. Imaging of the inflow cannula at the left ventricular apex in the traditional apical 4 chamber, apical 2 chamber, and parasternal long axis views is challenging by TTE mainly because of poor acoustic windows, image artifacts, large body habitus, and operator experience. PMID:24172272

  16. Corticotomy-assisted molar protraction with the aid of temporary anchorage device.

    Science.gov (United States)

    Uribe, Flavio; Janakiraman, Nandakumar; Fattal, Amine N; Schincaglia, Gian Pietro; Nanda, Ravindra

    2013-11-01

    This case report describes the interdisciplinary management of a 58-year-old woman who was missing lower first molars and supraerupted maxillary first molars. The treatment plan included intrusion of the upper first molars and corticotomy-assisted mandibular second molar protraction with the aid of temporary anchorage devices. Miniscrews were effective in intrusion of the maxillary first molars and protraction of the lower second molars. Although good functional outcome was achieved in 41 months, the corticotomy-assisted procedure did not significantly reduce the treatment time. PMID:23834274

  17. In vitro evaluation of an external compression device for fontan mechanical assistance.

    Science.gov (United States)

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

    2014-03-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Everett Christopher B

    2012-12-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  20. Usefulness of Palliative Care to Complement the Management of Patients on Left Ventricular Assist Devices.

    Science.gov (United States)

    Luo, Nancy; Rogers, Joseph G; Dodson, Gwen C; Patel, Chetan B; Galanos, Anthony N; Milano, Carmelo A; O'Connor, Christopher M; Mentz, Robert J

    2016-09-01

    Within the last decade, advancements in left ventricular assist device therapy have allowed patients with end-stage heart failure (HF) to live longer and with better quality of life. Like other life-saving interventions, however, there remains the risk of complications including infections, bleeding episodes, and stroke. The candidate for left ventricular assist device therapy faces complex challenges going forward, both physical and psychological, many of which may benefit from the application of palliative care principles by trained specialists. Despite these advantages, palliative care remains underused in many advanced HF programs. Here, we describe the benefits of palliative care, barriers to use within HF, and specific applications to the integrated care of patients on mechanical circulatory support. PMID:27474339

  1. 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

    2006-01-01

    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.

  2. The Magnitude of Errors Associated in Measuring the Loads Applied on an Assistive Device While Walking

    OpenAIRE

    Karimi, Mohammad Taghi; Jamshidi, Nima

    2012-01-01

    Measurement of the loads exerted on the limb is a fundamental part of designing of an assistive device, which has been done by using strain gauges or a transducer. Although calculation of loads applied on an orthosis coefficients achieved from calibration is a standard way, most of researchers determined the loads based on available equations. Therefore, the aim of this research is finding the accuracy of this method with respect to calibration. Some strain gauges were attached on the lateral...

  3. Left ventricular non-compaction cardiomyopathy and left ventricular assist device: a word of caution

    OpenAIRE

    Kornberger, A.; Stock, U. A.; Risteski, P.; Beiras Fernandez, A.

    2016-01-01

    Background In patients with left ventricular non-compaction (LVNC), implantation of a left ventricular assist device (LVAD) may be performed as a bridge to transplantation. In this respect, the particular characteristics of the left ventricular myocardium may represent a challenge. Case presentation We report a patient with LVNC who required urgent heart transplantation for inflow cannula obstruction nine months after receiving a LVAD. LVAD parameters, echocardiography and examination of the ...

  4. Immunochemical identification of human endothelial cells on the lining of a ventricular assist device.

    OpenAIRE

    Frazier, O. H.; Baldwin, R T; Eskin, S G; Duncan, J. M.

    1993-01-01

    We are studying the biologic (pseudointimal) lining that forms in the HeartMate (Thermo Cardiosystems, Inc.; Woburn, Massachusetts, USA), a left ventricular assist device with a pusher-plate blood pump, housed in solid titanium with uniquely textured blood-contacting surfaces. Sintered titanium microspheres cover the rigid surface, and integrally textured polyurethane lines the flexing diaphragm. The texture of the blood-contacting surfaces is designed to encourage formation of a biologic pse...

  5. Minimally invasive is the future of left ventricular assist device implantation

    OpenAIRE

    Makdisi, George; Wang, I-Wen

    2015-01-01

    There have been many factors that have allowed for progressive improvement in outcomes and lower complication rates. These include the improvement in left ventricular assist device (LVAD) technologies, combined with better understanding of patient management, all these. Nowadays the numbers of LVAD implantations exceed the number of annual heart transplants worldwide. Minimally invasive procedures are shown to improve the surgical outcome in both LVAD insertion and replacement. These minimall...

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

    OpenAIRE

    de Sá, Rosa Corrêa Leoncio; Airoldi, Vladimir Jesus Trava; 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

    2015-01-01

    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 bioma...

  7. In vivo assessment of hemocompatibility of a ventricular assist device in healthy swine

    OpenAIRE

    Sacristán, Catarina; Escobedo,Carlos R.; Bojalil, Rafael; Izaguirre,Raúl A.; Cortina,Evelyn; Aranda,Alberto; Catrip,Jorge; Lesprón,Ma del Carmen; Springall, Rashidi; Sacristán,Emilio

    2010-01-01

    Objective: To assess the hemocompatible performance of a novel implantable pneumatic ventricular assist device (VAD, Innovamédica, México) in healthy swine. The aim of this pilot study was first, to determine if short-term VAD implantation elicited a remarkable inflammatory response above that expected from surgical trauma; and second, to assess if heparinized or passivated VAD coatings, in combination with systemic anticoagulant or antiaggregant therapies, modified the VAD's hemocompatible p...

  8. The effect of Ventricular Assist Devices on cerebral autoregulation: A preliminary study

    Directory of Open Access Journals (Sweden)

    Dunster Kimble R

    2011-02-01

    Full Text Available Abstract Background The insertion of Ventricular Assist Devices is a common strategy for cardiovascular support in patients with refractory cardiogenic shock. This study sought to determine the impact of ventricular assist devices on the dynamic relationship between arterial blood pressure and cerebral blood flow velocity. Methods A sample of 5 patients supported with a pulsatile ventricular assist device was compared with 5 control patients. Controls were matched for age, co-morbidities, current diagnosis and cardiac output state, to cases. Beat-to-beat recordings of mean arterial pressure and cerebral blood flow velocity, using transcranial Doppler were obtained. Transfer function analysis was performed on the lowpass filtered pressure and flow signals, to assess gain, phase and coherence of the relationship between mean arterial blood pressure and cerebral blood flow velocity. These parameters were derived from the very low frequency (0.02-0.07 Hz, low frequency (0.07-0.2 Hz and high frequency (0.2-0.35 Hz. Results No significant difference was found in gain and phase values between the two groups, but the low frequency coherence was significantly higher in cases compared with controls (mean ± SD: 0.65 ± 0.16 vs 0.38 ± 0.19, P = 0.04. The two cases with highest coherence (~0.8 also had much higher spectral power in mean arterial blood pressure. Conclusions Pulsatile ventricular assist devices affect the coherence but not the gain or phase of the cerebral pressure-flow relationship in the low frequency range; thus whether there was any significant disruption of cerebral autoregulation mechanism was not exactly clear. The augmentation of input pressure fluctuations might contribute in part to the higher coherence observed.

  9. Plutonium-238: an ideal power source for intracorporeal ventricular assist devices?

    Science.gov (United States)

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

    2012-01-01

    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.

  10. Destination therapy with left ventricular assist devices: for whom and when?

    Science.gov (United States)

    Porepa, Liane F; Starling, Randall C

    2014-03-01

    Historically, cardiac transplantation is the only definitive therapy for mortality reduction, symptom reduction, and improved quality of life in advanced heart failure. Because of improvement in cardiovascular care there is now a growing number of patients such as the elderly and those with abundant comorbidity who are not eligible for cardiac transplant. Durable mechanical circulatory support is the new reality in the treatment of advanced heart failure in this population subset. The left ventricular assist device (LVAD) has evolved from humble origins as a short-term extracorporeal and pulsatile device into a durable intracorporeal continuous flow device capable of providing permanent support in the form of destination therapy (DT) LVAD. Data gathered from original landmark clinical trials including Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH), and the Heart Mate II Trial, and the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) provide insight into the type of patient and the timing in which to consider DT LVAD therapy. There are a number individual patient warning signs and symptoms that predate clinical decline; thus, identifying individuals who might benefit from a DT LVAD strategy. The adverse event burden that accompanies DT LVAD therapy cannot be ignored when considering LVAD as an adjunct to ongoing medical therapy. Trends in patient selection regarding mechanical circulatory support continue to evolve along with the technology. As more clinical outcome data are gathered we will continue to refine our patient selection criteria and timing of implant. PMID:24565254

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

    Directory of Open Access Journals (Sweden)

    Hongwu Wang, PhD

    2014-09-01

    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.

  12. An assistive device for congenital central hypoventilation syndrome outpatients during sleep.

    Science.gov (United States)

    Biffi, Emilia; Piazza, Caterina; Cavalleri, Matteo; Taddeo, Peter; Carcano, Alessandro; Morandi, Francesco; Reni, Gianluigi

    2014-10-01

    Congenital Central Hypoventilation Syndrome is a genetic disease characterized by alveolar hypoventilation and autonomic dysregulation. Patients have hypoventilations, especially during sleep, conditioning hypercapnia which can lead to neurological damage and death. They therefore need mechanical ventilators, that provide sufficient gas exchange, and pulse-oximeters that monitor oxy-hemoglobin blood concentration. Due to the restrictions regarding domiciliary assistive devices, the presence of a caregiver is required all night long. Currently, the only alarm systems available are the ones integrated in the ventilators and monitoring systems. During the night, multiple false alarms may occur, interrupting the sleep and causing anxiety. In this work we describe an assistive device that acquires real-time data from a pulse-oximeter, provides a multisensory stimulation if oxygen saturation falls under a certain threshold, and wakes up the patient if the hypoxia is severe. Tests on healthy subjects have shown that the device guarantees rapid awakenings, with a stimulator-dependent efficacy, and that it does not affect sleep efficiency. The purpose of the device is to determine a gentle awakening if mild hypoxia conditions persist, and to assure rapid awakening when a severe hypoxia occurs, reducing false alarms, improving the quality of sleep and increasing the self-sufficiency of the patients. PMID:25069973

  13. Two-photon laser-assisted device alteration in silicon integrated-circuits.

    Science.gov (United States)

    Serrels, Keith A; Erington, Kent; Bodoh, Dan; Farrell, Carl; Leslie, Neel; Lundquist, Theodore R; Vedagarbha, Praveen; Reid, Derryck T

    2013-12-01

    Optoelectronic imaging of integrated-circuits has revolutionized device design debug, failure analysis and electrical fault isolation; however modern probing techniques like laser-assisted device alteration (LADA) have failed to keep pace with the semiconductor industry's aggressive device scaling, meaning that previously satisfactory techniques no longer exhibit a sufficient ability to localize electrical faults, instead casting suspicion upon dozens of potential root-cause transistors. Here, we introduce a new high-resolution probing technique, two-photon laser-assisted device alteration (2pLADA), which exploits two-photon absorption (TPA) to provide precise three-dimensional localization of the photo-carriers injected by the TPA process, enabling us to implicate individual transistors separated by 100 nm. Furthermore, we illustrate the technique's capability to reveal speed-limiting transistor switching evolution with an unprecedented timing resolution approaching <10 ps. Together, the exceptional spatial and temporal resolutions demonstrated here now make it possible to extend optical fault localization to sub-14 nm technology nodes. PMID:24514459

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

    Directory of Open Access Journals (Sweden)

    Sanjay Orathi Patangi

    2013-01-01

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

  15. 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

    2008-01-01

    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

  16. In vivo quantification of intraventricular flow during left ventricular assist device support

    Science.gov (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

    2014-11-01

    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.

  17. Remission of chronic anthracycline-induced heart failure with support from a continuous-flow left ventricular assist device.

    Science.gov (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

    2012-01-01

    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.

  18. A thrombus susceptibility comparison of two pulsatile Penn State 50 cc left ventricular assist device designs.

    Science.gov (United States)

    Navitsky, Michael A; Deutsch, Steven; Manning, Keefe B

    2013-01-01

    Left ventricular assist devices (LVADs) have proven successful as bridge to transplant devices for patients awaiting donor organs. While survival rates continue to increase, destination therapy remains hindered by thrombus formation within the device. Research has shown that thrombosis is correlated to the fluid dynamics within the device and may be a result of sustained shear rates below 500 s(-1) on the polyurethane blood sac used in the Penn State pulsatile LVAD. Particle image velocimetry is used to compare flow within two 50 cc LVAD designs to assess fluid patterns and quantify wall shear rates in regions known from in vivo studies to be susceptible to thrombus formation. The two designs differ in their front face geometry. The V-1 model has an outward-facing "dome" whereas the face of the V-2 model is flat. A thrombus susceptibility metric, which uses measured wall shear rates and exposure times, was applied to objectively compare pump designs over the entire cardiac cycle. For each design, there are regions where wall shear rates remained below 500 s(-1) for the entire cardiac cycle resulting in high thrombus susceptibility potential. Results of this study indicate that the V-2 device had an overall lower propensity for thrombus formation in the current region of interest. PMID:22825798

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

    Science.gov (United States)

    Stanfield, J Ryan; Selzman, Craig H

    2013-03-01

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

    Directory of Open Access Journals (Sweden)

    Garrett G. Grindle

    2015-01-01

    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.

  1. [Rise of the machines? Left ventricular assist devices for treatment of severe heart failure].

    Science.gov (United States)

    Ujeyl, A; Krüger, M

    2015-11-01

    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. PMID:26530283

  2. [Rise of the machines? Left ventricular assist devices for treatment of severe heart failure].

    Science.gov (United States)

    Ujeyl, A; Krüger, M

    2015-11-01

    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.

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

    Directory of Open Access Journals (Sweden)

    L. Martínez-Ramos

    2011-12-01

    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.

  4. Robotic-Assisted Device in Posterior Spinal Fusion for a High Risk Thoraculombar Fracture in Ankylosing Spondylitis

    OpenAIRE

    Suliman, Ali; Wollstein, Ronit; Bernfeld, Benjamin; Bruskin, Alexander

    2014-01-01

    Fractures in ankylosing spondylitis (AS) are often difficult to treat and surgical treatment may be fraught with complications. We describe the use of a robotic-assisted device in the surgical treatment of an unstable L1 fracture in an elderly patient with chronic lymphocytic leukemia and AS. The postoperative course was uneventful and the patient was discharged after 3 days. The use of a robotic-assisted device in spine surgery is particularly indicated in difficult high risk cases.

  5. Current status of percutaneous right ventricular assist devices: First-in-man use of a novel dual lumen cannula.

    Science.gov (United States)

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

    2016-09-01

    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.

  6. 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.

    2013-01-01

    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

  7. Evolvement of left ventricular assist device: the implications on heart failure management.

    Science.gov (United States)

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

    2016-07-01

    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. PMID:27594870

  8. Risk factors predictive of right ventricular failure after left ventricular assist device implantation.

    Science.gov (United States)

    Drakos, Stavros G; Janicki, Lindsay; Horne, Benjamin D; Kfoury, Abdallah G; Reid, Bruce B; Clayson, Stephen; Horton, Kenneth; Haddad, Francois; Li, Dean Y; Renlund, Dale G; Fisher, Patrick W

    2010-04-01

    Right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation appears to be associated with increased mortality. However, the determination of which patients are at greater risk of developing postoperative RVF remains controversial and relatively unknown. We sought to determine the preoperative risk factors for the development of RVF after LVAD implantation. The data were obtained for 175 consecutive patients who had received an LVAD. RVF was defined by the need for inhaled nitric oxide for >/=48 hours or intravenous inotropes for >14 days and/or right ventricular assist device implantation. An RVF risk score was developed from the beta coefficients of the independent variables from a multivariate logistic regression model predicting RVF. Destination therapy (DT) was identified as the indication for LVAD implantation in 42% of our patients. RVF after LVAD occurred in 44% of patients (n = 77). The mortality rates for patients with RVF were significantly greater at 30, 180, and 365 days after implantation compared to patients with no RVF. By multivariate logistic regression analysis, 3 preoperative factors were significantly associated with RVF after LVAD implantation: (1) a preoperative need for intra-aortic balloon counterpulsation, (2) increased pulmonary vascular resistance, and (3) DT. The developed RVF risk score effectively stratified the risk of RV failure and death after LVAD implantation. In conclusion, given the progressively growing need for DT, the developed RVF risk score, derived from a population with a large percentage of DT patients, might lead to improved patient selection and help stratify patients who could potentially benefit from early right ventricular assist device implantation. PMID:20346326

  9. Hydraulic and hemodynamic performance of a minimally invasive intra-arterial right ventricular assist device.

    Science.gov (United States)

    Hsu, Po-Lin; Graefe, Roland; Boehning, Fiete; Wu, Chen; Parker, Jack; Autschbach, Rüdiger; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2014-09-01

    Right ventricular assistance is still in the early phase of development compared to left ventricular assist device (LVAD) technology. In order to provide flexible pulmonary support and potentially reduce the known complications, we propose a minimally invasive right ventricular assist device (MIRVAD), located in the pulmonary artery (PA) and operating in series with the right ventricle (RV). The MIRVAD is an intra-arterial rotary blood pump containing a single axial impeller, which is not enclosed by a rigid housing but stent-fixed within the vessel. The impeller geometry has been designed with the assistance of analytical methods and computational fluid dynamics (CFD). The hydraulic performance of the impeller was evaluated experimentally with a customized test setup using blood synthetic medium (HES). The blade-tip clearance (BTC) was varied between 0.25-4.25 mm to evaluate the effect of different PA sizes on impeller performance. Furthermore, the Langrangian particle-tracking method was used to estimate the level of hemolysis and generate numerical blood damage indexes.The impeller design generated 25.6 mmHg for flow rates of 5 lpm at a speed of 6,000 rpm at the baseline condition, capable of providing sufficient support for the RV. The BTC presented a significant effect on the static pressure generation and the efficiency, but the operational range is suitable for most vessel sizes. The numerical results demonstrated a low risk of blood damage at the design point (mean Lagrangian damage index 2.6*10(-7)). The preliminary results have encouraged further impeller optimization and development of the MIRVAD. PMID:25262631

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

    DEFF Research Database (Denmark)

    Jung, Mette Holme; Gustafsson, Finn

    2015-01-01

    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...... factors are anemia with low oxygen-carrying capacity, obesity and general deconditioning with low muscle mass. In addition, exercise training in CF-LVAD patients can improve peak VO2. To design interventions to improve functional capacity in patients treated with modern durable LVADs, a detailed...

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

    DEFF Research Database (Denmark)

    Moiseyenko, Rayisa; Bruus, Henrik

    2015-01-01

    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...... and streaming has received much attention, since it relies solely on mechanical properties such as particle size and contrast in density and compressibility. We present a theoretical study of phononic-assisted control of ultrasound waves in acoustofluidic devices. We propose the use of phononic crystal...

  12. A-GPS Assisted Wi-Fi Access Point Discovery on Mobile Devices for Energy Saving

    OpenAIRE

    Xia, Feng; Zhang, Wei; Ding, Fangwei; Hao, Ruonan

    2011-01-01

    Mobile devices have been shipped with multiple wireless network interfaces in order to meet their diverse communication and networking demands. In this paper, we propose an A-GPS assisted scheme that discovers the nearest Wi-Fi network access points (APs) by using user's location information. This allows the user to switch to the Wi-Fi interface in an intelligent manner when she/he arrives at the nearest Wi-Fi network AP. Therefore, it avoids the long periods in idle state and greatly reduces...

  13. Radical Cystectomy with Ileal Conduit Urinary Diversion in a Patient with a Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Joseph J. Pariser

    2015-01-01

    Full Text Available Left ventricular assist device (LVAD is an option for the surgical management of severe heart failure, and radical cystectomy remains the standard of care for muscle-invasive bladder cancer. Given a complicated population in terms of comorbidities and management for patients with an LVAD, there is little experience with major urologic procedures, which require balancing the benefits of surgery with considerable perioperative risks. We report our experience performing the first radical cystectomy with ileal conduit in a patient with an LVAD and muscle-invasive bladder cancer.

  14. Increase in circadian variation after continuous-flow ventricular assist device implantation.

    Science.gov (United States)

    Slaughter, Mark S; Ising, Michael S; Tamez, Daniel; O'Driscoll, Gerry; Voskoboynikov, Neil; Bartoli, Carlo R; Koenig, Steven C; Giridharan, Guruprasad A

    2010-06-01

    The circadian rhythm of varying blood pressure and heart rate is attenuated or absent in patients with severe heart failure. In 28 patients supported by a left ventricular assist device (LVAD) for at least 30 days, a restoration of the circadian rhythm was demonstrated by a consistent nocturnal decrease, and then increase, of the LVAD flow while at a constant LVAD speed. The return of the circadian rhythm has implications for cardiac recovery, and the observation indicates that the continuous-flow LVAD has an intrinsic automatic response to physiologic demands. PMID:20207167

  15. Safety and Feasibility of Laparoscopic Abdominal Surgery in Patients With Mechanical Circulatory Assist Devices.

    Science.gov (United States)

    Ashfaq, Awais; Chapital, Alyssa B; Johnson, Daniel J; Staley, Linda L; Arabia, Francisco A; Harold, Kristi L

    2016-10-01

    Objectives Increasing number of mechanical circulatory assist devices (MCADs) are being placed in heart failure patients. Morbidity from device placement is high and the outcome of patients who require noncardiac surgery after, is unclear. As laparoscopic interventions are associated with decreased morbidity, we examined the impact of such procedures in these patients. Methods A retrospective review was conducted on 302 patients who underwent MCAD placement from 2005 to 2012. All laparoscopic abdominal surgeries were included and impact on postoperative morbidity and mortality studied. Results Ten out of 16 procedures were laparoscopic with 1 conversion to open. Seven patients had a HeartMate II, 2 had Total Artificial Hearts, and 1 had CentriMag. Four patients had devices for ischemic cardiomyopathy and 6 cases were emergent. Surgeries included 6 laparoscopic cholecystectomies, 2 exploratory laparoscopies, 1 laparoscopic colostomy takedown, and 1 laparoscopic ventral hernia repair with mesh. Median age of the patients was 63 years (range, 29-79 years). Median operative time was 123 minutes (range, 30-380 minutes). Five of 10 patients were on preoperative anticoagulation with average intraoperative blood loss of 150 mL (range, 20-700 mL). There were 3 postoperative complications; acute respiratory failure, acute kidney injury and multisystem organ failure resulting in death not related to the surgical procedure. Conclusion The need for noncardiac surgery in post-MCAD patients is increasing due to limited donors and due to more durable and longer support from newer generation assist devices. While surgery should be approached with caution in this high-risk group, laparoscopic surgery appears to be a safe and successful treatment option. PMID:26839214

  16. Outcome of biventricular repair in infants with multiple left heart obstructive lesions.

    Science.gov (United States)

    Cavigelli-Brunner, Anna; Bauersfeld, Urs; Prêtre, René; Kretschmar, Oliver; Oxenius, Angela; Valsangiacomo Buechel, Emanuela R

    2012-04-01

    The decision to perform biventricular repair for infants with multiple obstructive or hypoplastic left heart lesions (LHL) and borderline left ventricle (LV) may be controversial. This study sought to assess the mortality and morbidity of patients with LHL after biventricular repair and to determine the growth of the left-sided cardiac structures. Retrospective analysis of 39 consecutive infants with LHL who underwent biventricular repair was performed. The median age at surgery was 7 days (range 1-225 days), and the median follow-up period was 34 months (range 1-177 months). Between diagnosis and the end of the follow-up period, the size of the aortic annulus (z-score -4.1 ± 2.8 vs. -0.1 ± 2.7) and the LV (LV end-diastolic diameter z-score -1.7 ± 2.8 vs. 0.21 ± 1.7) normalized. During the follow-up period, 23 patients required 39 reinterventions (62%) consisting of redo surgery for 21 patients (57%) and catheter-guided reinterventions for 8 patients (22%). At the end of the follow-up period, 25 of 34 patients were doing subjectively well; 10 children (29%) received cardiac medication; 12 (35%) presented with failure to thrive (weight ≤ P3) and 5 (15%) with pulmonary hypertension. The overall mortality rate was 13%. Biventricular repair for patients with multiple LHL results in sufficient growth of the left-sided cardiac structures. Nevertheless, residual or newly developing obstructive lesions and pulmonary hypertension are frequent, causing significant morbidity that requires reintervention. PMID:22159427

  17. Thrombosis in continuous-flow left ventricular assist devices: pathophysiology, prevention, and pharmacologic management.

    Science.gov (United States)

    Jennings, Douglas L; Weeks, Phillip A

    2015-01-01

    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

  18. 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.

    Science.gov (United States)

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

    2016-08-01

    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. PMID:27001080

  19. 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.

    Science.gov (United States)

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

    2016-08-01

    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.

  20. Biventricular stimulation to prevent cardiac desynchronization: rationale, design, and endpoints of the 'Biventricular Pacing for Atrioventricular Block to Prevent Cardiac Desynchronization (BioPace)' study.

    Science.gov (United States)

    Funck, Reinhard C; Blanc, Jean-Jacques; Mueller, Hans-Helge; Schade-Brittinger, Carmen; Bailleul, Christophe; Maisch, Bernhard

    2006-08-01

    Despite the deleterious effects of cardiac dyssynchrony and the positive effects of cardiac resynchronization therapy, patients with high-degree atrioventricular block continue to receive desynchronizing right ventricular (RV) pacing systems. Although it is unclear whether the negative effects of RV pacing and left bundle branch block (LBBB) are comparable, and whether they depend on the presence and the degree of structural heart disease, one may hypothesize that RV pacing may have similar effects to LBBB. In the BioPace trial, the long-term effects of RV pacing vs. biventricular pacing will be prospectively compared in 1200 pacemaker patients with high likelihood of mostly paced ventricular events, regardless of whether in sinus rhythm or in atrial fibrillation (AF). After echocardiographic examination of left ventricular (LV) function, patients will be randomly assigned to the implantation of an RV vs. a biventricular pacing system and followed for up to 5 years. Primary study endpoints are survival, quality of life (QoL), and the distance covered in a 6-min hall walk (6-MHW) at 24 months after implantation. Secondary endpoints are QoL and the 6-MHW result at 12 months after implantation, hospitalization rate, LV dimensions, LV ejection fraction, and the development of chronic AF and other adverse events. PMID:16864616

  1. Octreotide for the Management of Gastrointestinal Bleeding in a Patient with a HeartWare Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Geetanjali Dang

    2014-01-01

    Full Text Available HeartWare is a third generation left ventricular assist device (LVAD, widely used for the management of advanced heart failure patients. These devices are frequently associated with a significant risk of gastrointestinal (GI bleeding. The data for the management of patients with LVAD presenting with GI bleeding is limited. We describe a 56-year-old lady, recipient of a HeartWare device, who experienced recurrent GI bleeding and was successfully managed with subcutaneous (SC formulations of octreotide.

  2. 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

    2012-01-01

    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.

  3. Tissue Doppler echocardiography and biventricular pacing in heart failure: Patient selection, procedural guidance, follow-up, quantification of success

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2004-09-01

    Full Text Available Abstract Asynchronous myocardial contraction in heart failure is associated with poor prognosis. Resynchronization can be achieved by biventricular pacing (BVP, which leads to clinical improvement and reverse remodeling. However, there is a substantial subset of patients with wide QRS complexes in the electrocardiogram that does not improve despite BVP. QRS width does not predict benefit of BVP and only correlates weakly with echocardiographically determined myocardial asynchrony. Determination of asynchrony by Tissue Doppler echocardiography seems to be the best predictor for improvement after BVP, although no consensus on the optimal method to assess asynchrony has been achieved yet. Our own preliminary results show the usefulness of Tissue Doppler Imaging and Tissue Synchronization Imaging to document acute and sustained improvement after BVP. To date, all studies evaluating Tissue Doppler in BVP were performed retrospectively and no prospective studies with patient selection for BVP according to echocardiographic criteria of asynchrony were published yet. We believe that these new echocardiographic tools will help to prospectively select patients for BVP, help to guide implantation and to optimize device programming.

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

    Directory of Open Access Journals (Sweden)

    Ring Margareta

    2010-04-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  6. Communicating with assistive listening devices and age-related hearing loss: Perceptions of older Australians.

    Science.gov (United States)

    Aberdeen, Lucinda; Fereiro, David

    2014-01-01

    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. PMID:25267134

  7. 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)

    2007-11-15

    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.

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

    Directory of Open Access Journals (Sweden)

    Yu Jin Park

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Lee, ChaBum; Tarbutton, Joshua A.

    2014-09-01

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

  11. Correção biventricular em defeito do septo atrioventricular desbalanceado Corrección biventricular en defecto del septo atrioventricular desbalanceado Biventricular repair in unbalanced atrioventricular septal defect

    OpenAIRE

    Edmar Atik; Patrícia O. Marques; Rogério A. Miranda; Vitor C. Guerra; Lucília Santana Faria; Marcelo Jatene

    2009-01-01

    É apresentada a evolução favorável, após correção operatória biventricular, de criança com 2,5 anos de idade, com defeito do septo atrioventricular desbalanceado, com ventrículo esquerdo (VE) pequeno (anel mitral de 10 mm em relação de 0,4 com o anel tricúspide, DDVE de 17 mm, Vd2 VE de 15 ml/m² e relação do índice longitudinal VE/VD de 0,71). Houve desenvolvimento normal do VE, verificado três meses após a operação (anel mitral de 22 mm, em relação de 0,84 com o da valva tricúspide e DDVE de...

  12. Hybrid stent device of flow-diverting effect and stent-assisted coil embolization formed by fractal structure.

    Science.gov (United States)

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

    2016-05-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Basavana G Goudra

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-15

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

  15. Shape optimisation of a ventricular assist device using a VADFEM computer program.

    Science.gov (United States)

    Kopernik, Magdalena

    2013-01-01

    The Polish ventricular assist device, POLVAD_EXT, is made of a polymer designed to be covered with a nanocoating of titanium nitride to improve haemocompatibility. A loss of cohesion can occur between the coating and the substrate. An analysis of stress and strain states in a multi-scale model of the blood chamber was performed in the finite element computer program, VADFEM. The multiscale model is composed of a macro model of the blood chamber and a micro model of the titanium nitride (TiN) deposited on the polymer. The finite element method and the goal function, based on the triaxiality factor, are used to solve the problems formulated. The theories of non-linear elasticity and elasto-plasticity are applied. The goal of the paper is to optimise the construction of the POLVAD_EXT with respect to shape parameters. PMID:24215121

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

    Directory of Open Access Journals (Sweden)

    Yu-Ju Lan

    2007-02-01

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

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

    DEFF Research Database (Denmark)

    Jensen, Stina Bjørnskov; Brandt, Åse

    2011-01-01

    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......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....... 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...

  18. 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

    2015-01-01

    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...

  19. Partial nephrectomy in a patient with a left ventricular assist device.

    Science.gov (United States)

    Manger, Jules P; Kern, John A; Krupski, Tracey L

    2011-01-01

    Left ventricular assist device (LVAD) use has increased as a bridge to heart transplant as well as destination therapy in patients with severe heart failure. Presence of LVAD is not a contraindication to noncardiac surgery but does present special challenges to the surgical, anesthesia, and cardiac teams. We present the case of a 40-year-old woman with idiopathic cardiomyopathy necessitating LVAD who underwent left partial nephrectomy for a renal mass. She had undergone three nondiagnostic percutaneous image-guided biopsies. Left partial nephrectomy was performed. Perioperative care was without incident due to careful oversight by a multidisciplinary team. Pathology revealed high-grade clear cell renal cell carcinoma (RCC) with negative margins. Polytetrafluoroethylene (PTFE) bolsters were misidentified six months postoperatively on computed tomography (CT) at an outside institution as a retained laparotomy sponge. This is, to our knowledge, the first report of a partial nephrectomy performed in a patient with LVAD. PMID:22606616

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

    Directory of Open Access Journals (Sweden)

    Shawna J. Lee

    2015-07-01

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

  1. A novel interface for hybrid mock circulations to evaluate ventricular assist devices.

    Science.gov (United States)

    Ochsner, Gregor; Amacher, Raffael; Amstutz, Alois; Plass, André; Schmid Daners, Marianne; Tevaearai, Hendrik; Vandenberghe, Stijn; Wilhelm, Markus J; Guzzella, Lino

    2013-02-01

    This paper presents a novel mock circulation for the evaluation of ventricular assist devices (VADs), which is based on a hardware-in-the-loop concept. A numerical model of the human blood circulation runs in real time and computes instantaneous pressure, volume, and flow rate values. The VAD to be tested is connected to a numerical-hydraulic interface, which allows the interaction between the VAD and the numerical model of the circulation. The numerical-hydraulic interface consists of two pressure-controlled reservoirs, which apply the computed pressure values from the model to the VAD, and a flow probe to feed the resulting VAD flow rate back to the model. Experimental results are provided to show the proper interaction between a numerical model of the circulation and a mixed-flow blood pump. PMID:23204266

  2. Health-Promoting Physical Activity of Children Who Use Assistive Mobility Devices: A Scoping Review.

    Science.gov (United States)

    Jirikowic, Tracy L; Kerfeld, Cheryl I

    2016-01-01

    Children with physical disabilities who use assistive mobility devices (AMDs) are at risk for obesity and other secondary health conditions. Habitual physical activity is one lifestyle factor that may prevent obesity and contribute to overall health, and an active lifestyle in childhood improves prospects for lifelong healthy behaviors. Child, family, and environmental facilitators and barriers influence health-promoting physical activity (HPPA) for children without disabilities, but comparable models and levels of understanding for children who use AMDs are lacking. In this scoping review, we identified a similar set of child, family, and environmental facilitators and barriers relevant to HPPA participation among children who use AMDs. Noted gaps in the literature included limited reporting of AMD use, inconsistent HPPA definitions, and inadequate measurement tools for children who are nonambulatory. The identified child, family, and environmental factors provide a framework for occupational therapy practitioners and interprofessional teams to develop HPPA opportunities and interventions for an underserved population. PMID:27548861

  3. Minimally invasive is the future of left ventricular assist device implantation.

    Science.gov (United States)

    Makdisi, George; Wang, I-Wen

    2015-09-01

    There have been many factors that have allowed for progressive improvement in outcomes and lower complication rates. These include the improvement in left ventricular assist device (LVAD) technologies, combined with better understanding of patient management, all these. Nowadays the numbers of LVAD implantations exceed the number of annual heart transplants worldwide. Minimally invasive procedures are shown to improve the surgical outcome in both LVAD insertion and replacement. These minimally invasive techniques can be grouped grossly into shifting from on-pump to off-pump implantation, alternative access for implantation other than sternotomy, and a combination of both, which should be the ultimate aim of minimally invasive LVAD implantation. Here we describe the alternative techniques and configurations of minimally invasive and sites of implantation. PMID:26543617

  4. Minimally invasive is the future of left ventricular assist device implantation

    Science.gov (United States)

    Makdisi, George

    2015-01-01

    There have been many factors that have allowed for progressive improvement in outcomes and lower complication rates. These include the improvement in left ventricular assist device (LVAD) technologies, combined with better understanding of patient management, all these. Nowadays the numbers of LVAD implantations exceed the number of annual heart transplants worldwide. Minimally invasive procedures are shown to improve the surgical outcome in both LVAD insertion and replacement. These minimally invasive techniques can be grouped grossly into shifting from on-pump to off-pump implantation, alternative access for implantation other than sternotomy, and a combination of both, which should be the ultimate aim of minimally invasive LVAD implantation. Here we describe the alternative techniques and configurations of minimally invasive and sites of implantation. PMID:26543617

  5. Subchronic use of the St. Jude centrifugal pump as a mechanical assist device in calves.

    Science.gov (United States)

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

    1996-06-01

    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.

  6. Software Process Improvement to Assist Medical Device Software Development Organisations to Comply with the Amendments to the Medical Device Directive

    OpenAIRE

    Mc Hugh, Martin; McCaffery, Fergal; Casey, Valentine

    2012-01-01

    peer-reviewed A recent revision to the European Medical Device Directive (MDD) 2007/47/EC made fourteen amendments to the original directive (93/42/EEC). A number of these changes directly affect the development of software for use in healthcare. The most significant change in relation to medical device software development is that standalone software is now seen as an active medical device and should be developed following state of the art medical device software development p...

  7. Molecular changes after left ventricular assist device support for heart failure.

    Science.gov (United States)

    Birks, Emma J

    2013-08-30

    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.

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

    Directory of Open Access Journals (Sweden)

    Suzana Rabello

    2014-04-01

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

  9. [Temporary use of centrifugal pump for pump thrombosis in patients with paracorporeal ventricular assist device].

    Science.gov (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

    2015-05-01

    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.

  10. Centrifugal blood pump for temporary ventricular assist devices with low priming and ceramic bearings.

    Science.gov (United States)

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

    2013-11-01

    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.

  11. A modular mock circulation for hydromechanical studies on valves, stenoses, vascular grafts and cardiac assist devices.

    Science.gov (United States)

    Schima, H; Baumgartner, H; Spitaler, F; Kuhn, P; Wolner, E

    1992-07-01

    P6vices for hydrodynamic simulation are required in a variety of studies such as device evaluation, cardiovascular modeling and for student training. Most studies today use different, incompatible circuits, which must be redesigned for every new application. To obtain a universal apparatus, a unitized system with standard connectors was developed. Three types of connectors were selected: 1" flange connectors, 1/2" tubing connectors and Luer-connectors with a 2 mm lumen. The complete system consists of reservoirs, throttles, valve holders, adapters for Doppler ultrasound probes, and converters to link these basic diameters. The apparatus can be driven by membrane, centrifugal and geared pumps. The system has successfully been used in echocardiographic studies of stenosis and valvular insufficiency, for pulse propagation in vascular grafts, and to test the hydraulic performance of cardiac assist devices. Flow rates between 0.1 and 30 l/min and pressure gradients up to 250 mmHg were achieved. In practical use, the system can be adapted to suit various investigations, with minimal expense. Standardization of the parts and connectors results in simple documentation and good reproducibility. PMID:1516993

  12. Use of extracorporeal liver assist device and auxiliary liver transplantation in fulminant hepatic failure.

    Science.gov (United States)

    McCarthy, M; Ellis, A J; Wendon, J A; Heaton, N; Rela, M; Buxton-Thomas, M; Hughes, R D; Portmann, B C; Williams, R

    1997-04-01

    The case history of a 14-year-old boy with fulminant hepatic failure secondary to non-A, non-B hepatitis who fulfilled selection criteria for orthotopic liver transplantation is described. Two forms of liver support were used (extracorporeal liver assist device and an auxiliary partial orthotopic liver transplantation) to provide additional time to allow spontaneous recovery to occur. During the 66 h of extracorporeal haemoperfusion through the device, haemodynamic stability was maintained along with improvements in serum bilirubin (555 to 381 mumol/l), and international normalized ratio (INR) (3.7 to 2.9). Deterioration in these parameters was observed following cessation of treatment and 10 h later, after a donor liver had become available, an auxiliary transplant was performed. Clinical recovery, though initially slow, was eventually complete, with histopathological and scintigraphic evidence of full liver regeneration at 3 months. Withdrawal of his immunosuppressive drugs began at 6 months and was complete by 14 months after auxiliary transplantation. He has since remained well with normal liver function tests. Temporary liver support may provide additional time for spontaneous recovery of the native liver to occur in selected cases of fulminant hepatic failure, even when criteria are fulfilled for orthotopic liver grafting. PMID:9160207

  13. [Temporary use of centrifugal pump for pump thrombosis in patients with paracorporeal ventricular assist device].

    Science.gov (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

    2015-05-01

    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. PMID:25963778

  14. Preclinical testing of the Levitronix Ultramag pediatric cardiac assist device in a lamb model.

    Science.gov (United States)

    Tuzun, Egemen; Harms, Kelly; Liu, Dong; Dasse, Kurt A; Conger, Jeff L; Richardson, J Scott; Fleischli, Andreas; Frazier, O H; Radovancevic, Branislav

    2007-01-01

    We evaluated the effects of the Levitronix UltraMag pediatric ventricular assist system on healthy animals during 29- to 90-day periods by assessing hemocompatibility and hepatic and renal functions while operating the device in a flow range suitable for pediatric patients. Nine lambs (weight, 15 to 24 kg) received the Levitronix UltraMag with an outflow cannula anastomosed to the descending aorta and an inflow cannula inserted into the left ventricular apex. Pump function data were collected at 1-hour intervals, and postoperative hematology and clinical chemistry tests were performed weekly throughout the study. Complete necropsy and histopathologic examinations were performed at study termination. Pump and circuit were thoroughly inspected for evidence of thrombi. All animals reached the scheduled endpoint of 29 to 90 days without device-related problems. Mean flow was maintained at 1.14 +/- 0.19 L/min. Hematologic values were within normal range in all animals except in one lamb that had a severe hemolytic reaction after cefazolin sodium administration. In all animals, serum glutamic-oxaloacetic transaminase and creatinine kinase levels increased after surgery but gradually returned to normal limits within 1 week. Postmortem examination of the explanted organs revealed small infarcted areas in five lamb kidneys, but renal function was unaffected. All other major organs were unremarkable. In one explanted pump (a 30-day study), a small thrombus was seen within the impeller blade. The other eight pumps were free of thrombus. The Levitronix UltraMag successfully operated in pediatric flow ranges without device-related adverse events. PMID:17515735

  15. A review of assistive listening device and digital wireless technology for hearing instruments.

    Science.gov (United States)

    Kim, Jin Sook; Kim, Chun Hyeok

    2014-12-01

    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.

  16. Design method of a foldable ventricular assist device for minimally invasive implantation.

    Science.gov (United States)

    Hsu, Po-Lin; Wang, Yaxin; Amaral, Felipe; Parker, Jack; Schmitz-Rode, Thomas; Autschbach, Rüdiger; Steinseifer, Ulrich

    2014-04-01

    To date, ventricular assist devices (VADs) have become accepted as a therapeutic solution for end-stage heart failure patients when a donor heart is not available. Newer generation VADs allow for a significant reduction in size and an improvement in reliability. However, the invasive implantation still limits this technology to critically ill patients. Recently, expandable/deployable devices have been investigated as a potential solution for minimally invasive insertion. Such a device can be inserted percutaneously via peripheral vessels in a collapsed form and operated in an expanded form at the desired location. A common structure of such foldable pumps comprises a memory alloy skeleton covered by flexible polyurethane material. The material properties allow elastic deformation to achieve the folded position and withstand the hydrodynamic forces during operation; however, determining the optimal geometry for such a structure is a complex challenge. The numerical finite element method (FEM) is widely used and provides accurate structural analysis, but computation time is considerably high during the initial design stage where various geometries need to be examined. This article details a simplified two-dimensional analytical method to estimate the mechanical stress and deformation of memory alloy skeletons. The method was applied in design examples including two popular types of blade skeletons of a foldable VAD. Furthermore, three force distributions were simulated to evaluate the strength of the structures under different loading conditions experienced during pump operation. The results were verified with FEM simulations. The proposed two-dimensional method gives a close stress and deformation estimation compared with three-dimensional FEM simulations. The results confirm the feasibility of such a simplified analytical approach to reveal priorities for structural optimization before time-consuming FEM simulations, providing an effective tool in the initial

  17. Feasibility and safety of biventricular repair in neonates with hypoplastic left heart complex.

    Science.gov (United States)

    Bergonzini, S; Mendoza, A; Paz, M A; Garcia, E; Aguilar, J M; Arlati, F G; Galletti, L; Comas, J V

    2015-02-01

    Hypoplastic left heart syndrome is a spectrum of structural cardiac malformations characterized by variable underdevelopment of the left heart-aorta complex. A minority of patients having a milder degree of left ventricular hypoplasia, described as hypoplastic left heart complex (HLHC), may be selected for biventricular repair. The objective of this study was to assess the outcome of the biventricular approach in HLHC. We evaluated retrospectively 30 neonates diagnosed with HLHC from the "12 de Octubre" University Hospital, following established criteria. We analyzed the echocardiographic data recorded just after birth and at last follow-up after surgery. All patients were operated on in the neonatal period using various surgical techniques. There were no early deaths and only 1 late death after a mean follow-up of 62.9 ± 43.8 months. All patients presented a significant growth of the left ventricular structures, with a Z-score increase of 1.17 ± 1.05 for mitral annulus, 1.72 ± 1.23 for aortic annulus, and 1.33 ± 1.46 for left ventricular end-diastolic diameter. Postoperatively, 18 patients showed a left valvular stenosis, and 17 patients underwent a reoperation and/or an interventional procedure. Freedom from surgery or interventional catheterizations at 1, 3 and 5 years was 53, 49 and 43%, respectively. The 29 current survivors are all in a good functional status. In our experience, we achieved good results from biventricular repair in patients with HLHC, with a significant growth of left heart structures and an excellent clinical status at a medium-term follow-up. Nevertheless, there was a high rate of reoperations and/or interventional catheterizations.

  18. Frequency of seal disruption with the sarns centrifugal pump in postcardiotomy circulatory assist.

    Science.gov (United States)

    Curtis, J J; Boley, T M; Walls, J T; Demmy, T L; Schmaltz, R A

    1994-03-01

    We have used the Sarns centrifugal pump for uni- or biventricular assist in 58 patients with postcardiotomy cardiogenic shock. This device utilizes a spinning impeller pump that is magnetically coupled to a motor imparting rotary motion to incoming perfusate. Nine patients (16%) experienced 22 device failures, which consisted of a nonvisible disruption of the seal within the pumphead. This allowed fluid to accumulate between the pumphead and the motor necessitating change of the pumphead. The time to seal disruption was 10-149 h (median 48). Of the 22 seal disruptions, 18 occurred in 73 left ventricular pumps (25%), and 4 occurred in 38 right ventricular pumps (11%) p = 0.015. Left ventricular pumps failed at 10-144 h (median 48), and right ventricular pumps failed at 48-149 h (median 83) p = 0.02. The Sarns centrifugal pump is dependable for its intended use of cardiopulmonary perfusion. However, when used for postcardiotomy assist, seal disruption should be expected. It occurs sooner and is more common during left ventricular assist. We recommend inspection of the magnet chamber for evidence of seal disruption every 12 h with left ventricular assist and every 24 h with right ventricular assist.

  19. Thromboembolic stroke in patients with a HeartMate-II left ventricular assist device - the role of anticoagulation

    NARCIS (Netherlands)

    van den Bergh, Walter M.; Lansink-Hartgring, Annemieke Oude; van Duijn, Abram L.; Engström, Annemarie E.; Lahpor, Jaap R.; Slooter, Arjen J C

    2015-01-01

    Background and purpose: It is unknown what the optimal anticoagulant level is to prevent thromboembolic stroke in patients with left ventricular assist device (LVAD) support. We aimed to evaluate the relation between coagulation status and the occurrence of thromboembolic stroke in HeartMate-II LVAD

  20. Thromboembolic stroke in patients with a HeartMate-II left ventricular assist device - the role of anticoagulation

    NARCIS (Netherlands)

    van den Bergh, Walter M; Lansink-Hartgring, Annemieke Oude; van Duijn, Abram L; Engström, Annemarie E; Lahpor, Jaap R; Slooter, Arjen J C

    2015-01-01

    BACKGROUND AND PURPOSE: It is unknown what the optimal anticoagulant level is to prevent thromboembolic stroke in patients with left ventricular assist device (LVAD) support. We aimed to evaluate the relation between coagulation status and the occurrence of thromboembolic stroke in HeartMate-II LVAD

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

    DEFF Research Database (Denmark)

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

    2003-01-01

    The aim of this article is to describe the need for assistive devices and environmental modifications among long-living stroke survivors and to investigate if the need is continued and growing over time. The study sample of 155 consecutive stroke patients with stroke-related impairment, discharge...

  2. Photo-assisted water splitting with bipolar membrane induced pH gradients for practical solar fuel devices

    NARCIS (Netherlands)

    Vermaas, D.A.; Sassenburg, M.; Smith, W.A.

    2015-01-01

    Different pH requirements for a cathode and an anode result in a non-optimal performance for practical solar fuel systems. We present for the first time a photo-assisted water splitting device using a bipolar membrane, which allows a cathode to operate in an acidic electrolyte while the photoanode i

  3. The effects of stabilization exercise with an oral assistive device on pain and functionality of low back pain patients.

    Science.gov (United States)

    Lee, Jung-Ho; Park, Young-Han; Jang, Sang-Hun

    2015-10-01

    [Purpose] This study examined low back pain patients' decrease in pain and improvement in functionality after performance of a lumbar stabilization exercise using an oral assistive device, which can replace a lumbar assistive device. [Subjects and Methods] The experimental group (n=12) conducted a stabilization exercise using an oral assistive device after conventional physical therapy. The control group (n=12) received conventional physical therapy. In order to objectively measure pain in this study, a visual analogue scale (VAS) was used. In order to evaluate the subjects' functional aspects while living with low back pain, the Oswestry Disability Index (ODI) was used. [Results] There were statistically significant improvements in the comparison of the VAS and ODI of the experimental group and the control group. The experimental group's VAS and ODI significantly improved after the intervention compared to the control group. [Conclusion] The stabilization exercise using the assistive device after conventional physical therapy in the rehabilitation of low back pain patients reduced subjects' pain and increased their functional activities.

  4. Nipro extra-corporeal left ventricular assist device fitting after left ventricular reconstruction with mitral valve plasty.

    Science.gov (United States)

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

    2015-12-01

    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.

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

    Directory of Open Access Journals (Sweden)

    José Ignacio Izpura

    2013-01-01

    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.

  6. Biventricular diastolic function assessed by Doppler echocardiogram in children vertically infected with human immunodeficiency virus

    Directory of Open Access Journals (Sweden)

    Mauricio L. Silva

    2014-07-01

    Full Text Available OBJECTIVE: to determine, by Doppler-echocardiography, the frequency of cardiac diastolic dysfunction in asymptomatic and clinically stable pediatric patients with vertical infection by the human immunodeficiency virus (HIV, from the cardiovascular viewpoint. METHODS: this was an observational, prospective, and cross-sectional study, performed at a regional referral clinic for patients with HIV, in a convenience sample of 94 individuals, assessing biventricular diastolic function by Doppler-echocardiography, and weight, blood hemoglobin, and percentage of lymphocytes T-CD4+. RESULTS: fifty patients had diastolic dysfunction. Left ventricular dysfunction occurred in 38.7%, and the predominant type of dysfunction was decreased myocardial compliance. Right ventricular dysfunction was observed in 29.4% of the sample, and abnormal relaxation was the most prevalent type. Simultaneous biventricular dysfunction occurred in 14.1% of the individuals. There was no association between dysfunction and the immune status. CONCLUSIONS: diastolic dysfunction occurred, individually or simultaneously, with no association with immune status; decreased myocardial compliance was predominant in the left ventricle, and abnormal relaxation in the right ventricle.

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

    Institute of Scientific and Technical Information of China (English)

    Bente Grüer Sve(a)v1,; Margareta Scharin T(a)ng,; (A)sa Cider

    2012-01-01

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

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

    Science.gov (United States)

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

    2012-12-01

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

  9. Multicenter survey on the use of device-assisted enteroscopy in Portugal

    Science.gov (United States)

    Mascarenhas-Saraiva, Miguel; Mão-de-Ferro, Susana; Ferreira, Sara; Almeida, Nuno; Figueiredo, Pedro; Rodrigues, Adélia; Cardoso, Hélder; Marques, Margarida; Rosa, Bruno; Cotter, José; Vilas-Boas, Germano; Cardoso, Carla; Salgado, Marta; Marcos-Pinto, Ricardo

    2015-01-01

    Background Device-assisted enteroscopies (DAEs) are recent endoscopic techniques that enable direct endoscopic small-bowel evaluation. Objective The objective of this article is to evaluate the implementation of DAEs in Portugal and assess the main indications, diagnoses, diagnostic yield, therapeutic yield and complication rate. Methods We conducted a multicenter retrospective series using a national Web-based survey on behalf of the Portuguese Small-Bowel Study Group. Participants were asked to fill out two online databases regarding procedural data, indications, diagnoses, endoscopic therapy and complications using prospectively collected institutional data records. Results A total of eight centers were enrolled in the survey, corresponding to 1411 DAEs. The most frequent indications were obscure gastrointestinal bleeding (OGIB), inflammatory bowel disease and small-bowel tumors. The pooled diagnostic yield was 63%. A relation between the diagnostic yield and the indications was clear, with a diagnostic yield for OGIB of 69% (p = 0.02) with a 52% therapeutic yield. Complications occurred in 1.2%, with a major complication rate of 0.57%. Perforations occurred in four patients (0.28%). Conclusion DAEs are safe and effective procedures, with complication rates of 1.2%, the most serious of which is perforation. Most procedures are performed in the setting of OGIB. Diagnostic and therapeutic yields are dependent on the indication, hence appropriate patient selection is crucial. PMID:27087956

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

    Directory of Open Access Journals (Sweden)

    Peter Jirak

    2016-02-01

    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.

  11. Ventricular Assist Device in Single-Ventricle Heart Disease and a Superior Cavopulmonary Anastomosis.

    Science.gov (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

    2016-02-01

    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.

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

    Science.gov (United States)

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

    2014-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Paloma Morillas-Sendín

    2015-01-01

    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.

  14. Metal-assisted chemical etching of Ge surface and its effect on photovoltaic devices

    Science.gov (United States)

    Lee, Seunghyo; Choo, Hyeokseong; Kim, Changheon; Oh, Eunseok; Seo, Dongwan; Lim, Sangwoo

    2016-05-01

    Ge surfaces were etched by means of metal-assisted chemical etching (MaCE). The behavior of the MaCE reaction in diluted H2O2 was compared with that of a conventional etchant of HF/H2O2/H2O mixture (FPM). Herein we first report that a pyramidal structure on Ge (0 0 1) can be prepared by MaCE in dilute H2O2 solution, without the use of HF. Contrastingly, an octagonal trench structure was prepared by 4/5/1 FPM treatment of Ge (0 0 1) surface. This octagonal structure consisted of a square base, four large facets connected to the base, and other four small facets adjacent to the four large facets, which were considered to be (0 0 1), {1 1 0}, and {1 1 1}, respectively. The octagonal trench was formed as a result of the difference in etch rate of Ge depending on the orientation: {1 0 0} > {1 1 0} > {1 1 1}. Ge surfaces treated by MaCE exhibited improved solar cell efficiency due to their improved light absorption, which led to significant increases in the cells' short circuit current and fill factor. The results suggest that optimized MaCE procedures can be an effective method to improve the performance of Ge-based photovoltaic devices.

  15. Case study of radiation therapy treatment of a patient with a cardiac ventricular assist device.

    Science.gov (United States)

    Lasher, Donette E; Wojcicka, Jadwiga B; Malcom, Ronald; Shears, Lawrence L

    2008-01-01

    A patient with a cardiac ventricular assist device (VAD) with computer-controlled driver presented to our department for radiation therapy. The treatment plan was 4500 cGy to the rectum over 25 fractions with 15MV photon beams. All beams avoided the pump and leads. The response to electromagnetic interference (EMI) was evaluated by observing a duplicate driver in the treatment configuration as the patient's fields were delivered to a solid water equivalent phantom. Pretreatment dose assessment included calculations with Pinnacle treatment planning system, AAPM TG36 data analysis, and MOSFET measurements on the surface of the driver during the phantom irradiation. During the first patient treatment, MOSFETs were placed on the pump and leads, approximately 1cm from the left lateral treatment portal. No additional shielding was applied to the VAD. EMI was absent and the VAD operated normally during the pretreatment test and throughout the treatment course. Radiation to the driver was too low to be detected by the MOSFETS. Cumulative dose estimates to the pump were 425 cGy to 0.1cc (DVH), 368 cGy (TG36), and 158.5 cGy (MOSFET). MOSFET readings to the leads were 70.5 cGy. External beam radiation treatment was safely delivered to a VAD dependent patient. The VAD exhibited no adverse response to EMI and doses up to 425 cGy. Our results are based on one case and further study is encouraged. PMID:19020490

  16. Donor Oversizing Results in Improved Survival in Patients with Left Ventricular Assist Device.

    Science.gov (United States)

    Schumer, Erin M; Black, Matthew C; Rogers, Michael P; Trivedi, Jaimin R; Birks, Emma J; Lenneman, Andrew J; Cheng, Allen; Slaughter, Mark S

    2016-01-01

    Donor to recipient undersizing can result in diminished graft survival. The United Network for Organ Sharing database was retrospectively queried from January 2008 to December 2013 to identify adult patients who underwent heart transplantation. This population was divided into those without and with a left ventricular assist device (LVAD) at the time of transplant. Both groups were further subdivided into three groups: donor:recipient body mass index (BMI) ratio 1.2 (oversized). Kaplan-Meier analysis was used to compare graft survival. Cox regression analysis was used to identify factors affecting graft survival time. There was no difference in mean graft survival between undersized, matched, and oversized groups in patients without an LVAD (p = 0.634). Mean graft survival was significantly worse for undersized patients with an LVAD when compared with matched and oversized patients (p = 0.032). Cox regression revealed age, creatinine, waitlist time, United Network for Organ Sharing status, BMI ratio, and total bilirubin as significant factors affecting graft survival time. A donor to recipient BMI ratio of ≥1.2 results in significantly improved long-term graft survival for patients with an LVAD at the time of heart transplantation compared with patients with a BMI ratio of <1.2. An oversized organ should be considered for patients supported with an LVAD. PMID:27258226

  17. Elevation of procalcitonin after implantation of an interventional lung assist device in critically ill patients.

    Science.gov (United States)

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

    2014-01-01

    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.

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

    International Nuclear Information System (INIS)

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

  19. Management of anticoagulation and antiplatelet therapy in patients with left ventricular assist devices.

    Science.gov (United States)

    Baumann Kreuziger, Lisa M

    2015-04-01

    Left ventricular assist devices (LVADs) have increased the survival of patients with advanced heart failure fourfold. Despite these advances, significant bleeding and thrombotic complications occur. Hemorrhage requiring surgery has been reported in up to 30% of adults and 50% of children after LVAD placement. LVAD thrombosis and embolic stroke lead to significant long-term morbidity. Adults are treated with antithrombotic therapy to prevent thrombotic complications, but the amount and intensity of treatment differs between institutions. The goal international normalized ratio for warfarin therapy varies from 1.5 to 3.0. Some physicians manage adult LVAD patients without antiplatelet medication, whereas other adults are treated with aspirin as a single agent or combined with dipyridamole. In contrast, physicians typically manage children with LVADs using the Edmonton Anticoagulation and Platelet Inhibition Protocol, a detailed algorithm for anticoagulation and antiplatelet treatment modified based on thromboelastography results. LVAD implantation causes consumption of coagulation proteins, activation of fibrinolysis, and loss of high molecular weight von Willebrand protein multimers. How these changes in the coagulation system influence the risk of hemorrhage and initiation of thrombosis is unknown. Prospective, controlled studies are needed to determine the antithrombotic regimen that most effectively balances bleeding and thrombosis in LVAD patients. PMID:25549823

  20. Suction prevention and physiologic control of continuous flow left ventricular assist devices using intrinsic pump parameters.

    Science.gov (United States)

    Wang, Yu; Koenig, Steven C; Slaughter, Mark S; Giridharan, Guruprasad A

    2015-01-01

    The risk for left ventricular (LV) suction during left ventricular assist devices (LVAD) support has been a clinical concern. Current development efforts suggest LVAD suction prevention and physiologic control algorithms may require chronic implantation of pressure or flow sensors, which can be unreliable because of baseline drift and short lifespan. To overcome this limitation, we designed a sensorless suction prevention and physiologic control (eSPPC) algorithm that only requires LVAD intrinsic parameters (pump speed and power). Two gain-scheduled, proportional-integral controllers maintain a differential pump speed (ΔRPM) above a user-defined threshold to prevent LV suction while maintaining an average reference differential pressure (ΔP) between the LV and aorta. ΔRPM is calculated from noisy pump speed measurements that are low-pass filtered, and ΔP is estimated using an extended Kalman filter. Efficacy and robustness of the eSPPC algorithm were evaluated in silico during simulated rest and exercise test conditions for 1) excessive ΔP setpoint (ES); 2) rapid eightfold increase in pulmonary vascular resistance (PVR); and 3) ES and PVR. Simulated hemodynamic waveforms (LV pressure and volume; aortic pressure and flow) using only intrinsic pump parameters showed the feasibility of our proposed eSPPC algorithm in preventing LV suction for all test conditions. PMID:25396276

  1. Development of a flow rate monitoring method for the wearable ventricular assist device driver.

    Science.gov (United States)

    Ohnuma, Kentaro; Homma, Akihiko; Sumikura, Hirohito; Tsukiya, Tomonori; Takewa, Yoshiaki; Mizuno, Toshihide; Mukaibayashi, Hiroshi; Kojima, Koichi; Katano, Kazuo; Taenaka, Yoshiyuki; Tatsumi, Eisuke

    2015-06-01

    Our research institute has been working on the development of a compact wearable drive unit for an extracorporeal ventricular assist device (VAD) with a pneumatically driven pump. A method for checking the pump blood flow on the side of the drive unit without modifying the existing blood pump and impairing the portability of it will be useful. In this study, to calculate the pump flow rate indirectly from measuring the flow rate of the driving air of the VAD air chamber, we conducted experiments using a mock circuit to investigate the correlation between the air flow rate and the pump flow rate as well as its accuracy and error factors. The pump flow rate was measured using an ultrasonic flow meter at the inflow and outflow tube, and the air flow was measured using a thermal mass flow meter at the driveline. Similarity in the instantaneous waveform was confirmed between the air flow rate in the driveline and the pump flow rate. Some limitations of this technique were indicated by consideration of the error factors. A significant correlation was found between the average pump flow rate in the ejecting direction and the average air flow rate in the ejecting direction (R2 = 0.704-0.856), and the air flow rate in the filling direction (R2 = 0.947-0.971). It was demonstrated that the average pump flow rate was estimated exactly in a wide range of drive conditions using the air flow of the filling phase. PMID:25500948

  2. iOS--Worthy of the Hype as Assistive Technology for Visual Impairments? A Phenomenological Study of iOS Device Use by Individuals with Visual Impairments

    Science.gov (United States)

    Scott, Shari

    2013-01-01

    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…

  3. Use of Methylene Blue in the Treatment of Refractory Vasodilatory Shock After Cardiac Assist Device Implantation: Report of Four Consecutive Cases

    OpenAIRE

    Michel, Sebastian; Weis, Florian; Sodian, R; Beiras-Fernandez, Andres; Bigdeli, Amir K; Kaczmarek, Ingo; Bruegger, Dirk

    2012-01-01

    Vasodilatory shock frequently occurs after cardiac surgery, particularly after cardiac assist device implantation. This complication is often associated with high mortality, especially if refractory to conventional vasoconstrictor treatment. Methylene blue, a guanylate cyclase inhibitor, has been successfully used in the management of vasodilatory shock associated with cardiopulmonary bypass. We present four successive cases after implantation of cardiac assist devices suffering from norepine...

  4. Reproduction of continuous flow left ventricular assist device experimental data by means of a hybrid cardiovascular model with baroreflex control.

    Science.gov (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

    2014-06-01

    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

  5. The feasibility and efficacy of right ventricular assistance without thoracotomy.

    Science.gov (United States)

    Yano, M; Matsuo, K; Hatane, T; Araki, K; Onitsuka, T; Shibata, K; Koga, Y

    1993-01-01

    Mechanical right ventricular assistance has never been percutaneously instituted. We invented a new method for administering right ventricular assistance without thoracotomy (RAWT) and evaluated its effects in acute experiments using dogs. To institute RAWT, an outflow cannula was inserted into the pulmonary artery from the femoral vein, and an inflow cannula was inserted into the right atrium from the right jugular vein. A Swan-Ganz catheter inserted into the outflow cannula led it to the pulmonary artery under blood pressure monitoring only. A Sarns' centrifugal pump was used as a blood pump. We applied this system to biventricular failed hearts supported by a left ventricular assist device. We could increase cardiac output from 53.3 +/- 31.8 to 77.8 +/- 31.7 ml/min/kg, and mean aortic pressure from 43.5 +/- 12.3 to 57.5 +/- 11.2 mm Hg with RAWT. The right ventricular unloading effect of RAWT was not disturbed by regurgitation through the pulmonary or tricuspid valve.

  6. Left ventricular assist device weaning: hemodynamic response and relationship to stroke volume and rate reduction protocols.

    Science.gov (United States)

    Slaughter, Mark S; Sobieski, Michael A; Koenig, Steven C; Pappas, Patrokolos S; Tatooles, Antone J; Silver, Marc A

    2006-01-01

    Clinical evidence of myocardial recovery in a small cohort of patients supported with a left ventricular assist device (LVAD) has been reported. Development of an optimal LVAD weaning protocol is needed for these patients to sustain recovery after device explant. In this study, we tested the hypothesis that LVAD stroke volume reduction produces a steady-state mechanical reloading of left ventricular (LV) pressures and volumes compared with LVAD rate reduction that results in transient mechanical reloading of the heart due to beat-to-beat variation in LV pressures and volumes. The relationship of LVAD flow to LVAD stroke volume and systolic interval over a range of LVAD rates (60, 80, 100, 120, and 140 bpm) was validated in a mock circulatory flow loop. In six acute experiments, calves were implanted with a pneumatic paracorporeal LVAD (PVAD, Thoratec, Pleasanton, CA). The PVAD was operated asynchronously in the auto volume mode (full decompression) for 30 minutes to establish a baseline control condition. The calf hearts were then mechanically reloaded by LVAD rate reduction (80, 60, and 40 bpm) or LVAD stroke volume reduction (100, 120, and 140 bpm) protocols consisting of 30 minutes of support at each LVAD beat rate. The order of weaning protocols was randomized with a 30-minute recovery period (LVAD volume mode to fully decompress heart allowing it to rest) between protocols to enable return to baseline control state. Aortic pressure and flow, LV pressure and volume, pulmonary artery flow, and LVAD flow waveforms were recorded for each test condition. The LVAD stroke volume reduction protocol produced steady-state mechanical reloading compared with VAD rate reduction that resulted in transient LV mechanical reloading. This distinction is due to differences in their temporal relationships between LVAD and LV filling and emptying cycles. The acute hemodynamic benefit of LVAD stroke volume reduction was greater reduction in LV end-diastolic pressure and increase in

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

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27212720

  8. Monitoring hemostasis parameters in left ventricular assist device recipients – a preliminary report

    Science.gov (United States)

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

    2016-01-01

    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

  9. Evaluation of Physiological Control Systems for Rotary Left Ventricular Assist Devices: An In-Vitro Study.

    Science.gov (United States)

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

    2016-08-01

    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. PMID:26833037

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

    Directory of Open Access Journals (Sweden)

    Amit Kumar Mittal

    2016-01-01

    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.

  11. 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.

  12. Ventricular Assist Device implant (AB 5000) prototype cannula: In vitro assessment of MRI issues at 3-Tesla

    OpenAIRE

    Valencerina Samuel; Shellock Frank G

    2008-01-01

    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 ...

  13. Five-week use of a monopivot centrifugal blood pump as a right ventricular assist device in severe dilated cardiomyopathy.

    Science.gov (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

    2014-03-01

    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.

  14. Oxidative Stress, DNA Damage and Repair in Heart Failure Patients after Implantation of Continuous Flow Left Ventricular Assist Devices

    OpenAIRE

    Mondal, Nandan Kumar; Sorensen, Erik; Hiivala, Nicholas; Feller, Erika; Griffith, Bartley; Wu, Zhongjun Jon

    2013-01-01

    Objective: To study the status of oxidative stress and DNA damage repair in circulating blood leukocytes of heart failure patients supported by continuous flow left ventricular assist devices (LVADs). Materials and methods: Ten HF patients implanted with LVAD as bridge to transplant or destination therapy were enrolled in the study and 10 age and sex matched volunteers were recruited as the study control. Reactive oxygen species (ROS) in blood leukocytes and superoxide dismutase (SOD) in eryt...

  15. Computational Fluid Dynamics Analysis of Blade Tip Clearances on Hemodynamic Performance and Blood Damage in a Centrifugal Ventricular Assist Device

    OpenAIRE

    Wu, Jingchun; Paden, Bradley E.; Borovetz, Harvey S.; Antaki, James F.

    2009-01-01

    An important challenge facing the design of turbodynamic ventricular assist devices (VADs) intended for long-term support is the optimization of the flow path geometry to maximize hydraulic performance while minimizing shear-stress-induced hemolysis and thrombosis. For unshrouded centrifugal, mixed-flow and axial-flow blood pumps, the complex flow patterns within the blade tip clearance between the lengthwise upper surface of the rotating impeller blades and the stationary pump housing have a...

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

    Directory of Open Access Journals (Sweden)

    Chung-Min Wu

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Kardassis Dimitris

    2009-07-01

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

  18. Kawasaki Disease With Giant Coronary Aneurysms Requiring a Ventricular Assist Device to Separate From Extracorporeal Membrane Oxygenation: Coronary Issues Can Be a Pediatric Problem Too!

    Science.gov (United States)

    Adler, Adam C; Kodavatiganti, Ramesh

    2016-08-15

    Kawasaki disease, although common in children, may rarely affect the coronary arteries, leading to aneurysm formation and potential for coronary thrombus formation. Extremely rarely, coronary aneurysms from Kawasaki disease can thrombose, resulting in ischemic myocardium. We present a case of a 31-month-old patient requiring a left ventricular assist device after thrombosis of giant coronary aneurysms led to ischemic cardiomyopathy. At the termination of the surgical procedure, we encountered 2 periods of ventricular assist device dropout requiring intervention. With the increase in the number of pediatric patients with assist devices, we review the basic care for a patient requiring emergent surgery. PMID:27310902

  19. Thrombus formation patterns in the HeartMate II ventricular assist device: clinical observations can be predicted by numerical simulations.

    Science.gov (United States)

    Chiu, Wei-Che; Slepian, Marvin J; Bluestein, Danny

    2014-01-01

    Postimplant device thrombosis remains a life-threatening complication and limitation of continuous-flow ventricular assist devices (VADs). Using advanced computational fluid dynamic (CFD) simulations, we successfully depicted various flow patterns, recirculation zones, and stagnant platelet trajectories which promote thrombus formation and observed that they matched actual thrombus formation patterns observed in Thoratec HeartMate II VADs explanted from patients with pump thrombosis. Previously, these small eddies could not be captured by either digital particle image velocimetry or CFD due to insufficient resolution. Our study successfully demonstrated the potential capability of advanced CFD to be adopted for device optimization, leading to enhanced safety and efficacy of VADs for long-term destination therapy. PMID:24399065

  20. A ventricular assist device as a bridge to recovery, decision making, or transplantation in patients with advanced cardiac failure.

    Science.gov (United States)

    Neragi-Miandoab, Siyamek

    2012-10-01

    Despite many advances in the management of patients with heart failure, acute cardiogenic shock and progressive congestive heart failure remain serious problems with dismal prognoses. Both temporary and permanent mechanical support has been gaining wide clinical application in this patient population. Although mechanical circulatory support technology is rapidly evolving, this approach is associated with multiple issues such as the optimal duration of temporary support, ideal timing to bridge these patients to a long-term device, and selection of the right device for the right patient. The currently available devices are categorized into two major groups: temporary and long-term devices (including destination therapy). Heart failure is a dynamic condition, and the therapeutic approach may need to be modified depending on the patient's condition. Furthermore, the patient's preexisting morbidity, age, socioeconomic status, and family support are confounding factors that need to be considered when making such decisions. Clinical trials including prospective studies, as well as meticulous analysis of existing data, may help develop universal guidelines to select the right device. This manuscript will review the most widely used ventricular assist devices. PMID:22814623

  1. Ventricular Assist Devices and Increased Blood Product Utilization for Cardiac Transplantation

    Science.gov (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.

    2016-01-01

    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

  2. Fundus fluorescein angiographic findings in patients who underwent ventricular assist device implantation.

    Science.gov (United States)

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

    2013-09-01

    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

  3. 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

    2004-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Khayat Andre

    2011-01-01

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

  5. The mini-screen: an innovative device for computer assisted surgery systems.

    OpenAIRE

    Mansoux, Benoit; Nigay, Laurence; Troccaz, Jocelyne

    2005-01-01

    International audience In this paper we focus on the design of Computer Assisted Surgery (CAS) systems and more generally Augmented Reality (AR) systems that assist a user in performing a task on a physical object. Digital information or new actions are defined by the AR system to facilitate or to enrich the natural way the user would interact with the real environment. We focus on the outputs of such systems, so that additional digital information is smoothly integrated with the real envi...

  6. Autologous Platelet Concentrate and Vacuum-Assisted Closure Device Use in a Nonhealing Total Knee Replacement

    OpenAIRE

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

    2006-01-01

    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 conventiona...

  7. North Carolina Infant, Toddler & Preschooler Assistive Technology Needs Assessment. A Report on the Provision of Assistive Technology Devices and Services to Children with Disabilities from Birth to Age 5 in North Carolina.

    Science.gov (United States)

    Trachtman, Lawrence H.; Pierce, Patsy L.

    A survey of assistive technology use among North Carolina children with disabilities age 5 and under is reported and illustrated with graphs and charts. Responses from 160 agencies provided information on 2,217 children currently receiving or requiring assistive devices and services. Results are summarized in terms of demographic findings, costs…

  8. Fabrication of single TiO2 nanotube devices with Pt interconnections using electron- and ion-beam-assisted deposition

    Science.gov (United States)

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

    2016-06-01

    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.

  9. Acute contractile recovery extent during biventricular pacing is not associated with follow-up in patients undergoing resynchronization

    OpenAIRE

    Federica DeVecchi; Emanuela Facchini; Anna Degiovanni; Chiara Sartori; Chiara Cavallino; Matteo Santagostino; Virginia Di Ruocco; Andrea Magnani; Eraldo Occhetta; Paolo Nicola Marino

    2016-01-01

    Background: It has been reported that contractility, as assessed using dobutamine infusion, is independently associated with reverse remodeling after CRT. Controversy, however, exists about the capacity of this approach to predict a long-term clinical response. This study's purpose was to assess whether long-term CRT clinical effects can be predicted according to acute inotropic response induced by biventricular stimulation (CRT on), as compared with AAI–VVI right stimulation pacing mode (CRT...

  10. Totally implantable artificial hearts and left ventricular assist devices: selecting impermeable polycarbonate urethane to manufacture ventricles.

    Science.gov (United States)

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

    1999-01-01

    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

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

    KAUST Repository

    In, Jung Bin

    2012-09-25

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

  12. Ventricular Assist Device and Destination Therapy Candidates from Preoperative Selection Through End of Hospitalization.

    Science.gov (United States)

    Doty, Diane

    2015-12-01

    Mechanical circulatory support (MCS) devices offer advanced heart failure patients a potential long-term solution. MCS devices implantation is increasing related to the increased volume of heart failure patients, the shortfall of suitable donors, and the advanced technology and smaller size of the devices. To ensure a successful outcome, some key elements must be taken into consideration and managed: patient selection, preoperative preparation, intraoperative care, postoperative care, and posthospital education. The ultimate success of an MCS implantation relies on a multidisciplinary approach and excellent patient/caregiver education in each phase of hospitalization. PMID:26567498

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

    Directory of Open Access Journals (Sweden)

    Jens Garbade

    2012-01-01

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

  14. Bridge to thoracic organ transplantation in patients with pulmonary arterial hypertension using a pumpless lung assist device.

    Science.gov (United States)

    Strueber, M; Hoeper, M M; Fischer, S; Cypel, M; Warnecke, G; Gottlieb, J; Pierre, A; Welte, T; Haverich, A; Simon, A R; Keshavjee, S

    2009-04-01

    We describe a novel technique of pumpless extracorporeal life support in four patients with cardiogenic shock due to end-stage pulmonary hypertension (PH) including patients with veno-occlusive disease (PVOD) using a pumpless lung assist device (LAD). The device was connected via the pulmonary arterial main trunk and the left atrium, thereby creating a septostomy-like shunt with the unique addition of gas exchange abilities in parallel to the lung. Using this approach, all four patients were successfully bridged to bilateral lung transplantation and combined heart-lung transplantation, respectively. Although all patients presented in cardiogenic shock, hemodynamic unloading of the right ventricle using the low-resistance LAD stabilized the hemodynamic situation immediately so that no pump support was subsequently required. PMID:19344471

  15. 3D Printing to Guide Ventricular Assist Device Placement in Adults With Congenital Heart Disease and Heart Failure.

    Science.gov (United States)

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

    2016-04-01

    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. PMID:27033018

  16. Structural and composition investigations at delayered locations of low k integrated circuit device by gas-assisted focused ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dandan, E-mail: dandan.wang@globalfoundries.com; Kee Tan, Pik; Yamin Huang, Maggie; Lam, Jeffrey; Mai, Zhihong [Technology Development Department, GLOBALFOUNDRIES Singapore Pte. Ltd., 60 Woodlands Industrial Park D, Street 2, Singapore 738406 (Singapore)

    2014-05-15

    The authors report a new delayering technique – gas-assisted focused ion beam (FIB) method and its effects on the top layer materials of integrated circuit (IC) device. It demonstrates a highly efficient failure analysis with investigations on the precise location. After removing the dielectric layers under the bombardment of an ion beam, the chemical composition of the top layer was altered with the reduced oxygen content. Further energy-dispersive x-ray spectroscopy and Fourier transform infrared analysis revealed that the oxygen reduction lead to appreciable silicon suboxide formation. Our findings with structural and composition alteration of dielectric layer after FIB delayering open up a new insight avenue for the failure analysis in IC devices.

  17. A novel vacuum assisted closure therapy model for use with percutaneous devices

    OpenAIRE

    Cook, Saranne J.; Nichols, Francesca R.; Brunker, Lucille B.; Bachus, Kent N.

    2014-01-01

    Long-term maintenance of a dermal barrier around a percutaneous prosthetic device remains a common clinical problem. A technique known as Negative Pressure Wound Therapy (NPWT) uses negative pressure to facilitate healing of impaired and complex soft tissue wounds. However, the combination of using negative pressure with percutaneous prosthetic devices has not been investigated. The goal of this study was to develop a methodology to apply negative pressure to the tissues surrounding a percuta...

  18. Meta-Analysis of Usefulness of Percutaneous Left Ventricular Assist Devices for High-Risk Percutaneous Coronary Interventions.

    Science.gov (United States)

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

    2016-08-01

    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. PMID:27265673

  19. 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)

    2007-12-15

    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.

  20. In-vivo motion analysis of bi-ventricular hearts from tagged MR images

    Science.gov (United States)

    Park, Kyoungju; Axel, Leon; Metaxas, Dimitris N.

    2005-04-01

    We conduct experiments to look at the in-vivo cardiac motion during systole, to visualize heart contraction, and to examine the clinical usefulness. Our model-based technique incorporates subject-specific modeling, motion analysis and the extraction of clinically relevant parameters within one framework. Previous bi-ventricular model based method could only handle up to the mid-ventricles and have a few test-subjects. Our parameterized model includes the LV, RV and up to the basal area for full ventricular motion study. Finite element methods capture cardiac motion by tracking the material points from tagged Magnetic Resonance (MR) images. A number of experiments from ten subjects are evaluated and analyzed. We tested subject several times and compared the resulting parameters to ensure the reproducibility and deviations. The resulting parameters can be used to describe the cardiac motion of normal subjects. The patterns of normal subjects were derived from experiments. While significant shape and motion variations were apparent in normal subjects, the quantitative analysis show typical patterns. Generally, the basal area moves downwards and the apical area contracts towards the cavity. The principal strain analysis describes the directions and magnitudes of maximum shortening, and maximum thickening.

  1. Engineered embodiment: Comment on "The embodiment of assistive devices-from wheelchair to exoskeleton" by M. Pazzaglia and M. Molinari

    Science.gov (United States)

    Kannape, Oliver Alan; Lenggenhager, Bigna

    2016-03-01

    From brain-computer interfaces to wearable robotics and bionic prostheses - intelligent assistive devices have already become indispensable in the therapy of people living with reduced sensorimotor functioning of their physical body, be it due to spinal cord injury, amputation or brain lesions [1]. Rapid technological advances will continue to fuel this field for years to come. As Pazzaglia and Molinari [2] rightly point out, progress in this domain should not solely be driven by engineering prowess, but utilize the increasing psychological and neuroscientific understanding of cortical body-representations and their plasticity [3]. We argue that a core concept for such an integrated embodiment framework was introduced with the formalization of the forward model for sensorimotor control [4]. The application of engineering concepts to human movement control paved the way for rigorous computational and neuroscientific analysis. The forward model has successfully been adapted to investigate principles underlying aspects of bodily awareness such as the sense of agency in the comparator framework [5]. At the example of recent advances in lower limb prostheses, we propose a cross-disciplinary, integrated embodiment framework to investigate the sense of agency and the related sense of body ownership for such devices. The main onus now is on the engineers and cognitive scientists to embed such an approach into the design of assistive technology and its evaluation battery.

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

    Directory of Open Access Journals (Sweden)

    Vsevolod Yugov

    2013-07-01

    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.

  3. A numerical method to enhance the performance of a cam-type electric motor-driven left ventricular assist device.

    Science.gov (United States)

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

    2013-10-01

    Pulsatile left ventricular assist devices (LVADs) driven by electric motors have been widely accepted as a treatment of heart failure. Performance enhancement with computer assistance for this kind of LVAD has seldom been reported. In this article, a numerical method is proposed to assist the design of a cam-type pump. The method requires an integrated model of an LVAD system, consisting of a motor, a transmission mechanism, and a cardiovascular circulation. Performance indices, that is, outlet pressure, outlet flow, and pump efficiency, were used to select the best cam profile from six candidates. A prototype pump connected to a mock circulatory loop (MCL) was used to calibrate the friction coefficient of the cam groove and preliminarily evaluate modeling accuracy. In vitro experiments show that the mean outlet pressure and flow can be predicted with high accuracy by the model, and gross geometries of the measurements can also be reproduced. Simulation results demonstrate that as the total peripheral resistance (TPR) is fixed at 1.1 mm Hg.s/mL, the two-cycle 2/3-rise profile is the best. Compared with other profiles, the maximum increases of pressure and flow indices are 75 and 76%, respectively, and the maximum efficiency increase is over 51%. For different TPRs (0.5∼1.5 mm Hg.s/mL) and operation intervals (0.1∼0.4 s) in counterpulsation, the conclusion is also acceptable.

  4. A force-sensing device for assistance in soft-tissue balancing during knee arthroplasty

    OpenAIRE

    Crottet, Denis

    2006-01-01

    Nowadays, the large majority of the instrumentation for orthopaedic surgery consists of mechanical tools with varying degrees of complexity. To increase the accuracy and the safety of orthopaedic interventions, sensors and computers were recently introduced in the operating room. Computer Assisted Orthopaedic Surgery (CAOS) uses a navigation system that tracks the movements of surgical instruments in real-time and displays their exact location in relation to the operative area. Such technolog...

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

    DEFF Research Database (Denmark)

    Gonzalez, Javier; Hölzl, Michael; Riedl, Peter;

    2014-01-01

    is maintained with the components that have been loaded in the boot process for later audit. The first approach is often criticized for locking down devices, thus reducing users’ freedom to choose software. The second lacks the mechanisms to enforce any form of run-time verification. In this paper, we present...

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

    Directory of Open Access Journals (Sweden)

    Losada Gómez, A

    2007-02-01

    Full Text Available RESUMENEste artículo presenta los principales dispositivos de tecnología de asistencia que existen en Bogotá para facilitar el desempeño de la actividad de alimentación en personas que presentan algún tipo de discapacidad que limite esta ejecución, para ello, fue necesario realizar un estudio descriptivo donde se aplicó un instrumento tipo encuesta a personas que comercializan los mismos. Los principales resultados determinan que existen diferentes dispositivos para la función motora (mantener la postura sedente, facilitar agarres, facilitar patrón mano-boca y los patrones bucales (succión, deglución, masticación y digestión que se requieren en la alimentación. Como conclusión se determinó que actualmente en Colombia, los dispositivos de tecnología de asistencia para la alimentación son de baja tecnología y que existe fácil acceso a los mismos, pero se requiere realizar mayor difusión, también se encontró que no existen dispositivos que puedan facilitar esta actividad a personas que presenten parálisis en miembros superiores y que son mínimos los que presentan aplicación de tecnología de puntaABSTRACTThis article presents the principal devices of assistive technology that exist in Bogotá to facilitate the development of the activity of feeding in people that present some type of disability that limits this execution. Therefore, it was necessary to develop a descriptive study that included an instrument kind of inquiry to people that commercialize this devices. The principal results determine that there are different devices for the motor function (keep the sedentary posture, facilitate grips, facilitate hand-mouth patron and the buccal patrons (sucking, swallowing, chewing and digestion that are required in the feeding. As a conclusion it was determined that at present in Colombia, the devices of assistive technology for feeding have a low level of technology and there is an easy access to them, but is required to

  7. Trends in the Management of Patients With Left Ventricular Assist Devices Presenting for Noncardiac Surgery: A 10-Year Institutional Experience.

    Science.gov (United States)

    Stone, Marc; Hinchey, Joseph; Sattler, Christopher; Evans, Adam

    2016-09-01

    In our institution, the vast majority of patients presenting for noncardiac surgery (NCS) while supported by a left ventricular assist device (LVAD) are now cared for by noncardiac-trained anesthesiologists as the result of a decade of educational intervention to effect this transition. This represents a significant departure from the published experiences of other institutions. With institutional review board approval, we queried the database of our anesthesia record keeping system (CompuRecord) to determine various aspects of the perioperative management of these patients from July 1, 2003, through June 30, 2013, during which time 271 NCS procedures were performed on adult patients supported by LVADs. Over the entire study period (2003-2013), anesthetic care was provided by a cardiac anesthesiologist 47% of the time and by a noncardiac anesthesiologist 53% of the time. However, by the time period 2012-2013, 88% of the NCS procedures were staffed by a noncardiac anesthesiologist. Despite the prevalence of continuous flow devices in this series, the use of invasive blood pressure monitoring decreased dramatically by the later years of the study. Vasoactive and inotropic medications were rarely required intraoperatively. No intraoperative cardiac arrests, thromboembolic complications, or device malfunctions occurred. Our conclusion is that NCS procedures on LVAD-supported patients can be safely managed by educated noncardiac anesthesiologists. PMID:26685184

  8. PediaFlow™ Maglev Ventricular Assist Device: A Prescriptive Design Approach

    OpenAIRE

    Antaki, James F.; Ricci, Michael R.; Verkaik, Josiah E.; Snyder, Shaun T.; Maul, Timothy M.; Kim, Jeongho; Paden, Dave B.; Kameneva, Marina V.; Paden, Bradley E.; Wearden, Peter D.; Borovetz, Harvey S.

    2010-01-01

    This report describes a multi-disciplinary program to develop a pediatric blood pump, motivated by the critical need to treat infants and young children with congenital and acquired heart diseases. The unique challenges of this patient population require a device with exceptional biocompatibility, miniaturized for implantation up to 6 months. This program implemented a collaborative, prescriptive design process, whereby mathematical models of the governing physics were coupled with numerical ...

  9. Au Nanocluster assisted PCE improvement in PEDOT: PSS - Si Hybrid Devices

    Science.gov (United States)

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

    2015-03-01

    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.

  10. Driveline Infection Risk with Utilization of a Temporary External Anchoring Suture After Implantation of a Left Ventricular Assist Device.

    Science.gov (United States)

    Fudim, Marat; Brown, Christopher L; Davis, Mary E; Djunaidi, Monica; Danter, Matthew R; Harrell, Frank E; Stulak, John M; Haglund, Nicholas A; Maltais, Simon

    2016-01-01

    Driveline infections (DLI) are a cause of morbidity after continuous-flow left ventricular assist device (CF-LVAD) implantation. Because driveline trauma contributes to DLI, we assessed whether intraoperative placement of a temporary external anchoring suture (EAS) influenced DLI rate. We analyzed 161 consecutive patients with CF-LVAD (HMII 82; HW 79) implantation. Two groups were defined: placement of EAS (n = 85) or No EAS (n = 76). For NO EAS patients, the driveline was permanently anchored internally to the rectus fascia. Cox proportional analysis was performed to assess the effect of EAS on time to first confirmed DLI. Baseline characteristics were comparable between groups (all p = 0.3). Mean follow-up time was 0.93 years. A total of 18 (11.1%) patients developed confirmed culture positive DLI, with "first infection" rate of 0.13 events/year. Mean time to confirmed DLI was 0.69 years. Driveline infection was less likely (hazard ratio [HR] = 0.28, 0.95 confidence interval [CI] = 0.06-1.25, p = 0.056) to occur in NO EAS (2/18) then in EAS (16/18). Confirmed DLI was comparable between device types (p = 0.3). Multivariable regression adjusted for age, BMI, blood product use, device type, and diabetes showed equivocal effect of EAS (HR = 0.33, 0.95 CI = 0.07-1.54, p = 0.12). Patients with a temporary EAS may have an increased risk of confirmed DLI after device implantation. PMID:26809083

  11. The Enhanced Light Absorptance and Device Application of Nanostructured Black Silicon Fabricated by Metal-assisted Chemical Etching.

    Science.gov (United States)

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

    2016-12-01

    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. PMID:27368764

  12. 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.

    2015-06-01

    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.

  13. The use of percutaneous left ventricular assist device in high-risk percutaneous coronary intervention and cardiogenic shock.

    Science.gov (United States)

    Akhondi, Andre Babak; Lee, Michael S

    2013-01-01

    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.

  14. Two dimensional PMMA nanofluidic device fabricated by hot embossing and oxygen plasma assisted thermal bonding methods.

    Science.gov (United States)

    Yin, Zhifu; Sun, Lei; Zou, Helin; Cheng, E

    2015-05-29

    A method for obtaining a low-cost and high-replication precision two-dimensional (2D) nanofluidic device with a polymethyl methacrylate (PMMA) sheet is proposed. To improve the replication precision of the 2D PMMA nanochannels during the hot embossing process, the deformation of the PMMA sheet was analyzed by a numerical simulation method. The constants of the generalized Maxwell model used in the numerical simulation were calculated by experimental compressive creep curves based on previously established fitting formula. With optimized process parameters, 176 nm-wide and 180 nm-deep nanochannels were successfully replicated into the PMMA sheet with a replication precision of 98.2%. To thermal bond the 2D PMMA nanochannels with high bonding strength and low dimensional loss, the parameters of the oxygen plasma treatment and thermal bonding process were optimized. In order to measure the dimensional loss of 2D nanochannels after thermal bonding, a dimension loss evaluating method based on the nanoindentation experiments was proposed. According to the dimension loss evaluating method, the total dimensional loss of 2D nanochannels was 6 nm and 21 nm in width and depth, respectively. The tensile bonding strength of the 2D PMMA nanofluidic device was 0.57 MPa. The fluorescence images demonstrate that there was no blocking or leakage over the entire microchannels and nanochannels. PMID:25946991

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

    Directory of Open Access Journals (Sweden)

    Giuseppe Andreoni

    2014-01-01

    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.

  16. Differential regulation of microRNAs in end-stage failing hearts is associated with left ventricular assist device unloading.

    Science.gov (United States)

    Barsanti, Cristina; Trivella, Maria Giovanna; D'Aurizio, Romina; El Baroudi, Mariama; Baumgart, Mario; Groth, Marco; Caruso, Raffaele; Verde, Alessandro; Botta, Luca; Cozzi, Lorena; Pitto, Letizia

    2015-01-01

    Mechanical unloading by left ventricular assist devices (LVADs) in advanced heart failure (HF), in addition to improving symptoms and end-organ perfusion, is supposed to stimulate cellular and molecular responses which can reverse maladaptive cardiac remodeling. As microRNAs (miRNAs) are key regulators in remodeling processes, a comparative miRNA profiling in transplanted hearts of HF patients with/without LVAD assistance could aid to comprehend underlying molecular mechanisms. Next generation sequencing (NGS) was used to analyze miRNA differential expression in left ventricles of HF patients who underwent heart transplantation directly (n = 9) or following a period of LVAD support (n = 8). After data validation by quantitative real-time PCR, association with functional clinical parameters was investigated. Bioinformatics' tools were then used for prediction of putative targets of modulated miRNAs and relative pathway enrichment. The analysis revealed 13 upregulated and 10 downregulated miRNAs in failing hearts subjected to LVAD assistance. In particular, the expression level of some of them (miR-338-3p, miR-142-5p and -3p, miR-216a-5p, miR-223-3p, miR-27a-5p, and miR-378g) showed correlation with off-pump cardiac index values. Predicted targets of these miRNAs were involved in focal adhesion/integrin pathway and in actin cytoskeleton regulation. The identified miRNAs might contribute to molecular regulation of reverse remodeling and heart recovery mechanisms. PMID:25710008

  17. Scalable graphene synthesised by plasma-assisted selective reaction on silicon carbide for device applications

    Science.gov (United States)

    Tsai, Hsu-Sheng; Lai, Chih-Chung; Medina, Henry; Lin, Shih-Ming; Shih, Yu-Chuan; Chen, Yu-Ze; Liang, Jenq-Horng; Chueh, Yu-Lun

    2014-10-01

    Graphene, a two-dimensional material with honeycomb arrays of carbon atoms, has shown outstanding physical properties that make it a promising candidate material for a variety of electronic applications. To date, several issues related to the material synthesis and device fabrication need to be overcome. Despite the fact that large-area graphene films synthesised by chemical vapour deposition (CVD) can be grown with relatively few defects, the required transfer process creates wrinkles and polymer residues that greatly reduce its performance in device applications. Graphene synthesised on silicon carbide (SiC) has shown outstanding mobility and has been successfully used to develop ultra-high frequency transistors; however, this fabrication method is limited due to the use of costly ultra-high vacuum (UHV) equipment that can reach temperatures over 1500 °C. Here, we show a simple and novel approach to synthesise graphene on SiC substrates that greatly reduces the temperature and vacuum requirements and allows the use of equipment commonly used in the semiconductor processing industry. In this work, we used plasma treatment followed by annealing in order to obtain large-scale graphene films from bulk SiC. After exposure to N2 plasma, the annealing process promotes the reaction of nitrogen ions with Si and the simultaneous condensation of C on the surface of SiC. Eventually, a uniform, large-scale, n-type graphene film with remarkable transport behaviour on the SiC wafer is achieved. Furthermore, graphene field effect transistors (FETs) with high carrier mobilities on SiC were also demonstrated in this study.Graphene, a two-dimensional material with honeycomb arrays of carbon atoms, has shown outstanding physical properties that make it a promising candidate material for a variety of electronic applications. To date, several issues related to the material synthesis and device fabrication need to be overcome. Despite the fact that large-area graphene films

  18. Use of the Impella 2.5 left ventricular assist device in a patient with cardiogenic shock secondary to takotsubo cardiomyopathy.

    Science.gov (United States)

    Rashed, Ahmed; Won, Sekon; Saad, Marwan; Schreiber, Theodore

    2015-05-07

    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.

  19. Scalable graphene synthesised by plasma-assisted selective reaction on silicon carbide for device applications.

    Science.gov (United States)

    Tsai, Hsu-Sheng; Lai, Chih-Chung; Medina, Henry; Lin, Shih-Ming; Shih, Yu-Chuan; Chen, Yu-Ze; Liang, Jenq-Horng; Chueh, Yu-Lun

    2014-11-21

    Graphene, a two-dimensional material with honeycomb arrays of carbon atoms, has shown outstanding physical properties that make it a promising candidate material for a variety of electronic applications. To date, several issues related to the material synthesis and device fabrication need to be overcome. Despite the fact that large-area graphene films synthesised by chemical vapour deposition (CVD) can be grown with relatively few defects, the required transfer process creates wrinkles and polymer residues that greatly reduce its performance in device applications. Graphene synthesised on silicon carbide (SiC) has shown outstanding mobility and has been successfully used to develop ultra-high frequency transistors; however, this fabrication method is limited due to the use of costly ultra-high vacuum (UHV) equipment that can reach temperatures over 1500 °C. Here, we show a simple and novel approach to synthesise graphene on SiC substrates that greatly reduces the temperature and vacuum requirements and allows the use of equipment commonly used in the semiconductor processing industry. In this work, we used plasma treatment followed by annealing in order to obtain large-scale graphene films from bulk SiC. After exposure to N2 plasma, the annealing process promotes the reaction of nitrogen ions with Si and the simultaneous condensation of C on the surface of SiC. Eventually, a uniform, large-scale, n-type graphene film with remarkable transport behaviour on the SiC wafer is achieved. Furthermore, graphene field effect transistors (FETs) with high carrier mobilities on SiC were also demonstrated in this study. PMID:25307846

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

    Energy Technology Data Exchange (ETDEWEB)

    Bolat, Sami, E-mail: bolat@ee.bilkent.edu.tr; Tekcan, Burak [Department of Electrical and Electronics Engineering, Bilkent University, 06800, Ankara, Turkey and UNAM, National Nanotechnology Research Center, Bilkent University, 06800, Ankara (Turkey); Ozgit-Akgun, Cagla; Biyikli, Necmi [UNAM, National Nanotechnology Research Center, Bilkent University, 06800, Ankara, Turkey and Institute of Materials Science and Nanotechnology, Bilkent University, 06800, Ankara (Turkey); Okyay, Ali Kemal, E-mail: aokyay@ee.bilkent.edu.tr [Department of Electrical and Electronics Engineering, Bilkent University, 06800, Ankara (Turkey); UNAM, National Nanotechnology Research Center, Bilkent University, 06800, Ankara (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, 06800, Ankara (Turkey)

    2015-01-15

    Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metal–semiconductor–metal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) are demonstrated. Resistivity of GaN thin films and metal-GaN contact resistance are investigated as a function of annealing temperature. Effect of the plasma gas and postmetallization annealing on the performances of the TFTs as well as the effect of the annealing on the performance of MSM photodetectors are studied. Dark current to voltage and responsivity behavior of MSM devices are investigated as well. TFTs with the N{sub 2}/H{sub 2} PA-ALD based GaN channels are observed to have improved stability and transfer characteristics with respect to NH{sub 3} PA-ALD based transistors. Dark current of the MSM photodetectors is suppressed strongly after high-temperature annealing in N{sub 2}:H{sub 2} ambient.

  1. Failure Strain and Strain-Stress Analysis in Titanium Nitride Coatings Deposited on Religa Heart Ext Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Kopernik M.

    2015-04-01

    Full Text Available The Polish ventricular assist device is made of Bionate II with deposited TiN biocompatible nano-coating. The two scale finite element model is composed of a macro-model of blood chamber and a micro-model of the TiN/Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture. Therefore, the identification of a fracture parameter considered as a failure strain is the purpose of the present work. The tensile test in a micro chamber of the SEM was performed to calibrate the fracture parameter of the material system TiN/Bionate II. The failure strain is a function of a temperature, a thickness of coating and parameters of surface's profile. The failure strain was calculated at the stage of the test, in which the initiation of fracture occurred. The finite element micro-model includes the surface roughness and the failure strain under tension condition for two thicknesses of coatings which will be deposited on the medical device.

  2. Ventricular Assist Device implant (AB 5000 prototype cannula: In vitro assessment of MRI issues at 3-Tesla

    Directory of Open Access Journals (Sweden)

    Valencerina Samuel

    2008-05-01

    Full Text Available Abstract Purpose To evaluate MRI issues at 3-Tesla for a ventricular assist device (VAD. Methods The AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached (Abiomed, Inc., Danvers, MA was evaluated for magnetic field interactions, heating, and artifacts at 3-Tesla. MRI-related heating was assessed with the device in a gelled-saline-filled, head/torso phantom using a transmit/received RF body coil while performing MRI at a whole body averaged SAR of 3-W/kg for 15-min. Artifacts were assessed for the main metallic component of this VAD (atrial cannula using T1-weighted, spin echo and gradient echo pulse sequences. Results The AB5000 Ventricle with the prototype In-Flow Cannula and Out-Flow Cannula attached showed relatively minor magnetic field interactions that will not cause movement in situ. Heating was not excessive (highest temperature change, +0.8°C. Artifacts may create issues for diagnostic imaging if the area of interest is in the same area or close to the implanted metallic component of this VAD (i.e., the venous cannula. Conclusion The results of this investigation demonstrated that it would be acceptable for a patient with this VAD (AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached to undergo MRI at 3-Tesla or less. Notably, it is likely that the operation console for this device requires positioning a suitable distance (beyond the 100 Gauss line or in the MR control room from the 3-Tesla MR system to ensure proper function of the VAD.

  3. A phase separation method for analyses of fluoroquinones in meats based on ultrasound-assisted salt-induced liquid-liquid microextraction and a new integrated device

    OpenAIRE

    Wang, H; Gao, M.; Xu, Y; W. Wang; Zheng, L; Dahlgren, RA; Wang, X.

    2015-01-01

    © 2015 Elsevier Ltd. Herein, we developed a novel integrated device to perform phase separation based on ultrasound-assisted, salt-induced, liquid-liquid microextraction for determination of five fluoroquinones in meats by HPLC analysis. The novel integrated device consisted of three simple HDPE (high density polyethylene) parts that were used to separate the solvent from the aqueous solution prior to retrieving the extractant. The extraction parameters were optimized using the response surfa...

  4. Non-invasive Brain-Computer Interfaces for Semi-autonomous Assistive Devices

    Science.gov (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.

  5. Manipulation of Self-Assembled Microparticle Chains by Electroosmotic Flow Assisted Electrorotation in an Optoelectronic Device

    Directory of Open Access Journals (Sweden)

    Xiaolu Zhu

    2015-09-01

    Full Text Available A method incorporating the optically induced electrorotation (OER and alternating current electroosmotic (ACEO effects, for the formation and motion control of microparticle chains, is numerically and experimentally demonstrated. In this method, both the rotating electric field and ACEO fluid roll are generated around the border between light and dark area of the fluidic chamber in an optoelectronic tweezers (OET device. The experimental results show that the particle chains can self-rotate in their pitch axes under the rotating electric field produced due to the different impedances of the photoconductive layer in light and dark areas, and have a peak self-rotating rate at around 1 MHz. The orbital movement of entire particle chain around the center of ACEO fluid roll can be achieved from 0.5 to 600 kHz. The strength of OER motion and ACEO-caused orbital movement of particle chains can be adjusted by changing the frequency of alternating current (AC voltage. This non-contact method has the potential for spatially regulating the posture, orientation and position of microparticle chains.

  6. Laser-assisted ultrathin bare die packaging: a route to a new class of microelectronic devices

    Science.gov (United States)

    Marinov, Val R.; Swenson, Orven; Atanasov, Yuriy; Schneck, Nathan

    2013-03-01

    Ultrathin flip-chip semiconductor die packaging on paper substrates is an enabling technology for a variety of extremely low-cost electronic devices with huge market potential such as RFID smart forms, smart labels, smart tickets, banknotes, security documents, etc. Highly flexible and imperceptible dice are possible only at a thickness of less than 50 μm, preferably down to 10-20 μm or less. Several cents per die cost is achievable only if the die size is 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.

  7. 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

    2015-01-01

    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。

  8. PediaFlow™ Maglev Ventricular Assist Device: A Prescriptive Design Approach.

    Science.gov (United States)

    Antaki, James F; Ricci, Michael R; Verkaik, Josiah E; Snyder, Shaun T; Maul, Timothy M; Kim, Jeongho; Paden, Dave B; Kameneva, Marina V; Paden, Bradley E; Wearden, Peter D; Borovetz, Harvey S

    2010-03-01

    This report describes a multi-disciplinary program to develop a pediatric blood pump, motivated by the critical need to treat infants and young children with congenital and acquired heart diseases. The unique challenges of this patient population require a device with exceptional biocompatibility, miniaturized for implantation up to 6 months. This program implemented a collaborative, prescriptive design process, whereby mathematical models of the governing physics were coupled with numerical optimization to achieve a favorable compromise among several competing design objectives. Computational simulations of fluid dynamics, electromagnetics, and rotordynamics were performed in two stages: first using reduced-order formulations to permit rapid optimization of the key design parameters; followed by rigorous CFD and FEA simulations for calibration, validation, and detailed optimization. Over 20 design configurations were initially considered, leading to three pump topologies, judged on the basis of a multi-component analysis including criteria for anatomic fit, performance, biocompatibility, reliability, and manufacturability. This led to fabrication of a mixed-flow magnetically levitated pump, the PF3, having a displaced volume of 16.6 cc, approximating the size of a AA battery and producing a flow capacity of 0.3-1.5 L/min. Initial in vivo evaluation demonstrated excellent hemocompatibility after 72 days of implantation in an ovine. In summary, combination of prescriptive and heuristic design principles have proven effective in developing a miniature magnetically levitated blood pump with excellent performance and biocompatibility, suitable for integration into chronic circulatory support system for infants and young children; aiming for a clinical trial within 3 years. PMID:20544002

  9. Roles of universal three-dimensional image analysis devices that assist surgical operations.

    Science.gov (United States)

    Sakamoto, Tsuyoshi

    2014-04-01

    , 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. PMID:24535717

  10. 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;

    2009-01-01

    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...

  11. Lung perfusion and ventilation during implantation of left ventricular assist device as a strategy to avoid postoperative pulmonary complications and right ventricular failure

    OpenAIRE

    Macedo, Francisco Igor B.; Anthony L. PANOS; Andreopoulos, Fotios M.; Salerno, Tomas A.; Pham, Si M.

    2013-01-01

    Right ventricular failure is a major contributor to increased morbidity and mortality in patients undergoing left ventricular assist device implantation. Cardiopulmonary bypass is associated with increased pulmonary ischaemia and pulmonary vascular resistance. Continuous pulmonary perfusion and ventilation represents an emerging strategy for pulmonary protection during cardiac surgery. We hypothesize that this technique may have a pivotal role in reducing postoperative right ventricular dysfu...

  12. Successful use of the TandemHeart percutaneous ventricular assist device as a bridge to recovery for acute cellular rejection in a cardiac transplant patient.

    Science.gov (United States)

    Velez-Martinez, M; Rao, K; Warner, J; Dimaio, J; Ewing, G; Mishkin, J D; Mammen, P P A; Drazner, M H; Markham, D W; Patel, P C

    2011-12-01

    In this report, we presented a patient who benefited from hemodynamic support with the TandemHeart percutaneous ventricular assist device (pVAD; Cardiac Assist, Inc) implantation in the setting of early acute graft rejection 2 months after orthotopic heart transplant. The TandemHeart initially had been used for temporary hemodynamic assistance during postcardiotomy heart failure and high-risk coronary interventions. More recently, its use in patients with cardiogenic shock from acute myocardial infarction, fulminant myocarditis, and critical aortic stenosis has been reported. To our knowledge, this is one of the first reported cases in which the TandemHeart pVAD served as a successful device for support during acute cardiac transplant rejection. PMID:22172864

  13. Should eligibility for heart transplantation be a requirement for left ventricular assist device use? Recommendations based on a systematic review.

    Science.gov (United States)

    Boothroyd, Lucy J; Lambert, Laurie J; Sas, Georgeta; Guertin, Jason R; Ducharme, Anique; Charbonneau, Éric; Carrier, Michel; Cecere, Renzo; Morin, Jean E; Bogaty, Peter

    2013-12-01

    Left ventricular assist devices (LVADs) are used in chronic end-stage heart failure as "bridge to transplantation" (BTT) and, more recently, for transplant-ineligible patients as "destination therapy" (DT). We reviewed the evidence on clinical effects and cost-effectiveness of 2 types of continuous-flow LVADs (HeartMate II [HM II] and HeartWare), for BTT and DT patients. We systematically searched the scientific literature (January 2008-June 2012) and identified 14 clinical studies (approximately 2900 HM II and approximately 200 HeartWare patients), and 3 economic evaluations (HM II) using simulation models. Data were, however, limited to 2-3 studies per outcome. We made policy recommendations on the basis of our systematic review. Although complications after implantation are frequent, LVAD therapy is often highly effective across transplantation eligibility status and device, with 1-year survival reaching 86% for BTT and 78% for DT (compared with 25% for medical therapy). Neither BTT nor DT currently meet traditional cost-effectiveness limits in models using historical data, although BTT is standard practice for a limited number of patients in many regions. We found that BTT and DT as implantation strategies tend to be no longer mutually exclusive. We conclude that evidence is sufficient to support LVAD use, regardless of transplantation eligibility status, as long as patients are carefully selected and program infrastructure and budget are adequate. However, evidence gaps, limitations in economic models, and the lack of Canadian data point to the importance of mandatory, systematic monitoring of LVAD use and outcomes. PMID:23978595

  14. A novel snare assistance safeguards against early embolization of devices and facilitates quick retrieval of malpositioned devices in atrial septal defects with deficient margins

    OpenAIRE

    Sreeja Pavithran; Kothandam Sivakumar

    2015-01-01

    Background : Embolization might complicate device closure of large atrial septal defects (ASDs) with deficient margins. When margins are deficient, a precariously placed device can appear to be held in good position by the rigid delivery cable. Once the cable is unscrewed, the device adopts the natural lie of the interatrial septum. This can occasionally expose the inadequately captured margins and lead to device embolization. Most embolizations occur immediately after release. Retrieval of t...

  15. Hemolysate-mediated platelet aggregation: an additional risk mechanism contributing to thrombosis of continuous flow ventricular assist devices.

    Science.gov (United States)

    Tran, Phat L; Pietropaolo, Maria-Grazia; Valerio, Lorenzo; Brengle, William; Wong, Raymond K; Kazui, Toshinobu; Khalpey, Zain I; Redaelli, Alberto; Sheriff, Jawaad; Bluestein, Danny; Slepian, Marvin J

    2016-07-01

    Despite the clinical success and growth in the utilization of continuous flow ventricular assist devices (cfVADs) for the treatment of advanced heart failure, hemolysis and thrombosis remain major limitations. Inadequate and/or ineffective anticoagulation regimens, combined with high pump speed and non-physiological flow patterns, can result in hemolysis which often is accompanied by pump thrombosis. An unexpected increase in cfVADs thrombosis was reported by multiple major VAD implanting centers in 2014, highlighting the association of hemolysis and a rise in lactate dehydrogenase (LDH) presaging thrombotic events. It is well established that thrombotic complications arise from the abnormal shear stresses generated by cfVADs. What remains unknown is the link between cfVAD-associated hemolysis and pump thrombosis. Can hemolysis of red blood cells (RBCs) contribute to platelet aggregation, thereby, facilitating prothrombotic complications in cfVADs? Herein, we examine the effect of RBC-hemolysate and selected major constituents, i.e., lactate dehydrogenase (LDH) and plasma free hemoglobin (pHb) on platelet aggregation, utilizing electrical resistance aggregometry. Our hypothesis is that elements of RBCs, released as a result of shear-mediated hemolysis, will contribute to platelet aggregation. We show that RBC hemolysate and pHb, but not LDH, are direct contributors to platelet aggregation, posing an additional risk mechanism for cfVAD thrombosis. PMID:26590166

  16. Single axis controlled hybrid magnetic bearing for left ventricular assist device: hybrid core and closed magnetic circuit.

    Science.gov (United States)

    da Silva, Isaias; Horikawa, Oswaldo; Cardoso, Jose R; Camargo, Fernando A; Andrade, Aron J P; Bock, Eduardo G P

    2011-05-01

    In previous studies, we presented main strategies for suspending the rotor of a mixed-flow type (centrifugal and axial) ventricular assist device (VAD), originally presented by the Institute Dante Pazzanese of Cardiology (IDPC), Brazil. Magnetic suspension is achieved by the use of a magnetic bearing architecture in which the active control is executed in only one degree of freedom, in the axial direction of the rotor. Remaining degrees of freedom, excepting the rotation, are restricted only by the attraction force between pairs of permanent magnets. This study is part of a joint project in development by IDPC and Escola Politecnica of São Paulo University, Brazil. This article shows advances in that project, presenting two promising solutions for magnetic bearings. One solution uses hybrid cores as electromagnetic actuators, that is, cores that combine iron and permanent magnets. The other solution uses actuators, also of hybrid type, but with the magnetic circuit closed by an iron core. After preliminary analysis, a pump prototype has been developed for each solution and has been tested. For each prototype, a brushless DC motor has been developed as the rotor driver. Each solution was evaluated by in vitro experiments and guidelines are extracted for future improvements. Tests have shown good results and demonstrated that one solution is not isolated from the other. One complements the other for the development of a single-axis-controlled, hybrid-type magnetic bearing for a mixed-flow type VAD.

  17. Left ventricular assist device support with a centrifugal pump for 2 months in a 5-kg child.

    Science.gov (United States)

    Inoue, Takafumi; Nishimura, Takashi; Murakami, Arata; Itatani, Keiichi; Takaoka, Tetsuhiro; Kitahori, Kazuo; Umeki, Akihide; Takezoe, Toshiko; Kashiwa, Koichi; Kyo, Shunei; Ono, Minoru

    2011-09-01

    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.

  18. Template-assisted selective epitaxy of III–V nanoscale devices for co-planar heterogeneous integration with Si

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, H., E-mail: sih@zurich.ibm.com; Borg, M.; Moselund, K.; Cutaia, D.; Riel, H. [IBM Research – Zurich, 8803 Rüschlikon (Switzerland); Gignac, L.; Breslin, C. M.; Bruley, J. [IBM Research – T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

    2015-06-08

    III–V nanoscale devices were monolithically integrated on silicon-on-insulator (SOI) substrates by template-assisted selective epitaxy (TASE) using metal organic chemical vapor deposition. Single crystal III–V (InAs, InGaAs, GaAs) nanostructures, such as nanowires, nanostructures containing constrictions, and cross junctions, as well as 3D stacked nanowires were directly obtained by epitaxial filling of lithographically defined oxide templates. The benefit of TASE is exemplified by the straightforward fabrication of nanoscale Hall structures as well as multiple gate field effect transistors (MuG-FETs) grown co-planar to the SOI layer. Hall measurements on InAs nanowire cross junctions revealed an electron mobility of 5400 cm{sup 2}/V s, while the alongside fabricated InAs MuG-FETs with ten 55 nm wide, 23 nm thick, and 390 nm long channels exhibit an on current of 660 μA/μm and a peak transconductance of 1.0 mS/μm at V{sub DS} = 0.5 V. These results demonstrate TASE as a promising fabrication approach for heterogeneous material integration on Si.

  19. Constrictive Pericarditis in the Presence of Remaining Remnants of a Left Ventricular Assist Device in a Heart Transplanted Patient

    Directory of Open Access Journals (Sweden)

    R. Rivinius

    2015-01-01

    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.

  20. Hemodynamic influence of tilting disc valve type on pump performance with the NIPRO-ventricular assist device.

    Science.gov (United States)

    Kimura, Mitsutoshi; Nishimura, Takashi; Kinoshita, Osamu; Kashiwa, Koichi; Kyo, Shunei; Ono, Minoru

    2012-06-01

    The NIPRO-ventricular assist device (NIPRO-VAD) is an external pulsatile flow pump. Formerly, Sorin Carbocast, a monoleaflet tilting disc valve (SC valve), was used at the inlet/outlet parts of the pump, but Medtronic Hall (MH valve) is now used. We studied the differences in performance among pumps with different artificial valves. Six NIPRO pumps with SC valves and six with MH valves were examined using mock circuits. The systolic flow of the pump was measured with the ultrasonic flowmeter by changing the systolic fraction. Six patients wearing the NIPRO-VAD underwent periodic pump exchange from a pump with an SC valve to the one with an MH valve. The pump blood flow was measured at pre- and post-pump exchanges using an ultrasonic flowmeter. Blood pressure, serum LDH and AST levels were also compared before and after the pump exchange. Blood flow was significantly increased by using the NIPRO-VAD with the MH valve as compared to the SC valve in vitro. Under the same drive conditions pump flow tended to increase in six patients. No difference was found in patients' blood pressure, serum LDH or AST levels when using the SC or MH valve. From these results, the hemodynamic influence on patients due to replacement of the SC valve with the MH valve in the NIPRO-VAD is considered to be insignificant. PMID:22076421

  1. 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;

    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...

  2. EQUIPO PORTATIL PARA ASISTIR LA COSECHA MANUAL DE CAFE PORTABLE DEVICE TO ASSIST MANUAL HARVESTING OF COFFEE

    Directory of Open Access Journals (Sweden)

    Carlos Eugenio Oliveros Tascón

    2005-12-01

    -weight portable device was developed to assist manual harvesting of coffee. The device, driven by an 84,7 W DC motor, consisted of a 0,85 kg actuator carried in the operator’s hand and an 8 kg back-mounted frame to carry the batteries. Two rotating beaters made of Teflon, turning at 1.100 rpm, detach the fruits. With the new device it is possible to obtain massive detachment in clusters with high concentrations of mature fruits, avoiding the “fruit grabbing” which demands 40 % of the time needed in a manual harvesting cycle. The inertia of the motor and the mechanism is enough to detach up to 4 fruits after turning the device off. The device, called IMFRA 3DC (stands for the spanish words “IMpactador de FRutos” - fruit beater artifact, was evaluated in Timbío ( Cauca, Colombia , in the main harvesting season of 2004. The evaluation was conducted in a plantation with 2-year old coffee trees of the Red Colombia variety. The trees were planted in a 1,5 m x 1,0 m pattern, in flat terrain, and each tree had two stems. The average mature fruit charge and concentration were 1,43 kg and 80,7 %, respectively. With the device, a net yield of 33,7 kg/h per operator was obtained, almost three times greater than that observed in traditional hand picking. The harvesting quality improved conspicuously when the operators were more familiar with the apparatus; the first day they harvested 10,3 % of immature fruits and the fourth day they harvested just 4,3 %. The effectiveness was close to 80 %, which is acceptable when an additional harvesting pass is required. The results obtained indicate that the IMFRA 3DC is a promissing tool to assist in manual harvesting in high-density coffee plantations and to reduce production costs.

  3. Using Assistive Devices

    Medline Plus

    Full Text Available ... use it and how high it should be, what the safety considerations are. Dr. Roland Moskowitz: The ... big difference. Dr. Rebecca Jaffe: They can choose what they feel most comfortable with. For me to ...

  4. Using Assistive Devices

    Medline Plus

    Full Text Available [music] Marian Minor, Physical Therapist, Ph.D.: The proper use of a properly fitted cane can make ... to redistribute the weight at the knee. Occupational therapy is important in the overall management -- the non- ...

  5. Using Assistive Devices

    Medline Plus

    Full Text Available ... way to use it -- takes a lot of stress off that extremity. Some people who have difficulty will benefit from having orthotics in their shoes to redistribute the weight at the knee. Occupational therapy is important in the overall management -- the non-pharmacological management -- because patients have lost ...

  6. Using Assistive Devices

    Medline Plus

    Full Text Available ... because patients have lost a function. For example, one of the early complaints of osteoarthritis to the ... such as long-handled tongs -- to put on one's socks or put on one's shoes may make ...

  7. Using Assistive Devices

    Medline Plus

    Full Text Available ... but they don't know how to use it, where to use it and how high it should be, what the safety considerations are. Dr. ... cane in the opposite hand -- most people use it in the same side which is not the ...

  8. Using Assistive Devices

    Medline Plus

    Full Text Available ... to redistribute the weight at the knee. Occupational therapy is important in the overall management -- the non-pharmacological management -- because patients have lost a function. For example, one of ...

  9. Device-Training for Individuals with Thoracic and Lumbar Spinal Cord Injury Using a Powered Exoskeleton for Technically Assisted Mobility: Achievements and User Satisfaction

    Directory of Open Access Journals (Sweden)

    Thomas Platz

    2016-01-01

    Full Text Available Objective. Results of a device-training for nonambulatory individuals with thoracic and lumbar spinal cord injury (SCI using a powered exoskeleton for technically assisted mobility with regard to the achieved level of control of the system after training, user satisfaction, and effects on quality of life (QoL. Methods. Observational single centre study with a 4-week to 5-week intensive inpatient device-training using a powered exoskeleton (ReWalk™. Results. All 7 individuals with SCI who commenced the device-training completed the course of training and achieved basic competences to use the system, that is, the ability to stand up, sit down, keep balance while standing, and walk indoors, at least with a close contact guard. User satisfaction with the system and device-training was documented for several aspects. The quality of life evaluation (SF-12v2™ indicated that the use of the powered exoskeleton can have positive effects on the perception of individuals with SCI regarding what they can achieve physically. Few adverse events were observed: minor skin lesions and irritations were observed; no falls occurred. Conclusions. The device-training for individuals with thoracic and lumbar SCI was effective and safe. All trained individuals achieved technically assisted mobility with the exoskeleton while still needing a close contact guard.

  10. Device-Training for Individuals with Thoracic and Lumbar Spinal Cord Injury Using a Powered Exoskeleton for Technically Assisted Mobility: Achievements and User Satisfaction.

    Science.gov (United States)

    Platz, Thomas; Gillner, Annett; Borgwaldt, Nicole; Kroll, Sylvia; Roschka, Sybille

    2016-01-01

    Objective. Results of a device-training for nonambulatory individuals with thoracic and lumbar spinal cord injury (SCI) using a powered exoskeleton for technically assisted mobility with regard to the achieved level of control of the system after training, user satisfaction, and effects on quality of life (QoL). Methods. Observational single centre study with a 4-week to 5-week intensive inpatient device-training using a powered exoskeleton (ReWalk™). Results. All 7 individuals with SCI who commenced the device-training completed the course of training and achieved basic competences to use the system, that is, the ability to stand up, sit down, keep balance while standing, and walk indoors, at least with a close contact guard. User satisfaction with the system and device-training was documented for several aspects. The quality of life evaluation (SF-12v2™) indicated that the use of the powered exoskeleton can have positive effects on the perception of individuals with SCI regarding what they can achieve physically. Few adverse events were observed: minor skin lesions and irritations were observed; no falls occurred. Conclusions. The device-training for individuals with thoracic and lumbar SCI was effective and safe. All trained individuals achieved technically assisted mobility with the exoskeleton while still needing a close contact guard. PMID:27610382

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

    Science.gov (United States)

    Jung, Mette H; Gustafsson, Finn; Houston, Brian; Russell, Stuart D

    2016-01-01

    Ramp studies-measuring changes in cardiac parameters as a function of serial pump speed changes (revolutions per minute [rpm])-are increasingly used to evaluate function and malfunction of continuous-flow left ventricular assist devices (CF-LVADs). We hypothesized that ramp studies can predict functional capacity, quality of life (QOL), and survival in CF-LVAD patients. Hemodynamic changes per Δrpm were measured at a minimum of CF-LVAD support, at baseline pump speed, and at maximal tolerable pump speed. Subsequently functional capacity and QOL were assessed. Eighty ramp tests were performed in 44 patients (HeartMate II, Thoratec Corporation, Pleasanton, CA). Functional status was evaluated in 70% (31/44); average 6 minute walk test (6MWT) was 312 ± 220 min, New York Heart Association (NYHA) I-II/III-IV (70/30%) and activity scores very low-low/moderate-very high (55/45%). Decrease in pulmonary capillary wedge pressure per Δrpm was related to better NYHA classification; NYHA I-II vs. III-IV, -0.29 ± 0.15 vs. -0.09 ± 0.16 mm Hg/rpm * 10 (p = 0.007) as well as to activity score; very low-low vs. moderate-very high, -0.16 ± 0.16 vs. -0.31 ± 0.16 mm Hg/rpm * 10 (p = 0.02). Cardiac output change per Δrpm was correlated to measures of QOL. Ramp tests did not predict survival. In conclusion, hemodynamic changes during ramp studies are associated with measures of functional capacity and QOL. Hence, such tests could potentially identify patients in risk of failure to thrive during CF-LVAD support. PMID:27195741

  12. Computational fluid dynamics analysis of blade tip clearances on hemodynamic performance and blood damage in a centrifugal ventricular assist device.

    Science.gov (United States)

    Wu, Jingchun; Paden, Bradley E; Borovetz, Harvey S; Antaki, James F

    2010-05-01

    An important challenge facing the design of turbodynamic ventricular assist devices (VADs) intended for long-term support is the optimization of the flow path geometry to maximize hydraulic performance while minimizing shear-stress-induced hemolysis and thrombosis. For unshrouded centrifugal, mixed-flow and axial-flow blood pumps, the complex flow patterns within the blade tip clearance between the lengthwise upper surface of the rotating impeller blades and the stationary pump housing have a dramatic effect on both the hydrodynamic performance and the blood damage production. Detailed computational fluid dynamics (CFD) analyses were performed in this study to investigate such flow behavior in blade tip clearance region for a centrifugal blood pump representing a scaled-up version of a prototype pediatric VAD. Nominal flow conditions were analyzed at a flow rate of 2.5 L/min and rotor speed of 3000 rpm with three blade tip clearances of 50, 100, and 200 microm. CFD simulations predicted a decrease in the averaged tip leakage flow rate and an increase in pump head and axial thrust with decreasing blade tip clearances from 200 to 50 microm. The predicted hemolysis, however, exhibited a unimodal relationship, having a minimum at 100 microm compared to 50 microm and 200 microm. Experimental data corroborate these predictions. Detailed flow patterns observed in this study revealed interesting fluid dynamic features associated with the blade tip clearances, such as the generation and dissipation of tip leakage vortex and its interaction with the primary flow in the blade-blade passages. Quantitative calculations suggested the existence of an optimal blade tip clearance by which hydraulic efficiency can be maximized and hemolysis minimized. PMID:19832736

  13. Mechanistic pathway(s) of acquired von willebrand syndrome with a continuous-flow ventricular assist device: in vitro findings.

    Science.gov (United States)

    Dassanayaka, Sujith; Slaughter, Mark S; Bartoli, Carlo R

    2013-01-01

    In patients with a ventricular assist device (VAD), diminished high-molecular-weight von Willebrand factor (vWF) multimers may contribute to a bleeding diathesis. The mechanistic pathway(s) of vWF degradation and the role of ADAMTS-13, the vWF-cleaving metalloproteinase, are unknown. The objective of this study was to investigate the molecular mechanisms of VAD-induced vWF impairment in an in vitro system.Simple, mock circulatory loops (n = 4) were developed with a clinically approved, paracorporeal continuous-flow VAD. The loops were primed with anticoagulated, whole bovine blood (750 ml). The VAD was operated at constant blood flow and pressure. Blood samples were drawn at baseline and hourly for 6 hours. vWF multimers and ADAMTS-13 protein were quantified by agarose and polyacrylamide gel electrophoresis with immunoblotting. Plasma platelet factor 4 (PF4), a marker of platelet activation, was quantified via ELISA.Within 120 minutes, high-molecular-weight vWF multimers decreased, and low-molecular-weight multimers increased. Multiple low-molecular-weight vWF fragments emerged (~140, 176, 225, and 310 kDa). Total plasma ADAMTS-13 increased by 13 ± 3% (p < 0.05). Plasma PF4 increased by 21 ± 7% (p = 0.05).During VAD support, vWF degradation occurred quickly. Multiple mechanisms were responsible and included vWF cleavage by ADAMTS-13 (140 and 176 kDa fragments), and what may have been mechanical demolition of endogenous plasma vWF (225 kDa fragments) and nascent vWF (225 and 310 kDa fragments) from platelets. A modest increase in plasma ADAMTS-13 from activated platelets may have contributed to this process but was not the major mechanism. Mechanical demolition was likely the dominant process and warrants further evaluation. PMID:23438773

  14. Dynamics and prognostic role of galectin-3 in patients with advanced heart failure, during left ventricular assist device support and following heart transplantation

    OpenAIRE

    Coromilas, Ellie; Que-Xu, Em-Claire; Moore, D’Vesharronne; Kato, Tomoko S.; Wu, Christina; Ji, Ruiping; Givens, Raymond; Jorde, Ulrich P.; Takayama, Hiroo; NAKA, YOSHIFUMI; George, Isaac; Mancini, Donna; Schulze, P. Christian

    2016-01-01

    Background Galectin-3 is a marker of myocardial inflammation and fibrosis shown to correlate with morbidity and mortality in heart failure (HF). We examined the utility of galectin-3 as a marker of the severity of HF, the response of galectin-3 levels to ventricular assist device (LVAD) implantation or heart transplantation (HTx), and its use as a prognostic indicator. Methods Plasma galectin-3 was measured using a commercially available ELISA assay in patients with stable HF (n = 55), severe...

  15. 49 CFR 39.93 - What wheelchairs and other assistive devices may passengers with a disability bring onto a...

    Science.gov (United States)

    2010-10-01

    ... 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...

  16. 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

    2007-07-01

    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.

  17. Computer assisted optimisation on non-pharmacological treatment of congestive heart failure and supraventricular arrhythmia

    OpenAIRE

    Reumann, Matthias

    2007-01-01

    Heart Failure is the most common cardiac disease worldwide; supraventricular arrhythmia the most common cardiac arrhythmia. The understanding of these diseases advances treatment options. Ablation therapy and atrial antitachycardial pacing are non-pharmacological options in the treatment of atrial fibrillation. Cardiac resynchronization therapy with biventricular pacing devices has been shown successful in patients with severe heart failure. However, an optimization or even individual therapy...

  18. The attitudes of Australian radiography students towards the use of assistive transfer devices to reduce biomechanical stress in the clinical setting

    International Nuclear Information System (INIS)

    The duties performed by radiographers, which includes transferring patients onto and off the examination table, can increase their risk of developing back and neck pain. This study used a survey to identify the assistive transfer devices Australian radiography undergraduate students are familiar with and have had practise using in the clinical setting. It also sought to determine whether students are being encouraged by other radiographers to use these devices during clinical training and if they would conform to practicing unsafe transfers if instructed to by senior staff. Results indicated that radiography students were familiar with the majority of the surveyed assistive devices such as the Patslide and X-ray cassette slider. Many of the students were unlikely to participate in unsafe work practices and were able to provide alternative methods of transferring patients. However, some of the respondents could be coerced into participating in unsafe patient transfers. Radiographers should therefore be vigilant in refraining from practicing unsafe transfer techniques as it could lead to students believing it is acceptable and emulating these practices in the work place

  19. The Application of Bileaflet Mechanical Heart Valves in the Polish Ventricular Assist Device: Physical and Numerical Study and First Clinical Usage.

    Science.gov (United States)

    Malota, Zbigniew; Sadowski, Wojciech; Krzyskow, Marek; Stolarzewicz, Bogdan

    2016-03-01

    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.

  20. 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)

    陈亮

    2012-01-01

    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.

  1. Novel insights on effect of atrioventricular programming of biventricular pacemaker in heart failure – a case series

    Directory of Open Access Journals (Sweden)

    Rafique Asim M

    2006-10-01

    Full Text Available Abstract Background Echocardiography plays an integral role in the diagnosis of congestive heart failure including measurement of left heart pressure as well as mechanical dyssynchrony. Methods In this report we describe novel therapeutic uses of echo pulsed wave Doppler in atrioventricular pacemaker optimization in patients who had either not derived significant symptomatic benefit post biventricular pacemaker implantation or deteriorated after deriving initial benefit. In these patients atrioventricular optimization showed novel findings and improved cardiac output and symptoms. Results In 3 patients with Cheyne Stokes pattern of respiration echo Doppler showed worsening of mitral regurgitation during hyperpneac phase in one patient, marked E and A fusion in another patient and exaggerated ventricular interdependence in a third patient thus highlighting mechanisms of adverse effects of Cheyne Stokes respiration in patients with heart failure. All 3 patients required a very short atrioventricular delay programming for best cardiac output. In one patient with recurrent congestive heart failure post cardiac resynchronization, mitral inflow pulse wave Doppler showed no A wave until a sensed atrioventricular delay of 190 ms was reached and showed progressive improvement in mitral inflow pattern until an atrioventricular delay of 290 ms. In 2 patients atrioventricular delay as short as 50 ms was required to allow E and A separation and prevent diastolic mitral regurgitation. All patients developed marked improvement in congestive heart failure symptoms post echo-guided biv pacemaker optimization. Conclusion These findings highlight the value of echo-guided pacemaker optimization in symptomatic patients post cardiac resynchronization treatment.

  2. Animal magnetocardiography using superconducting quantum interference device gradiometers assisted with magnetic nanoparticle injection: A sensitive method for early detecting electromagnetic changes induced by hypercholesterolemia

    Science.gov (United States)

    Wu, C. C.; Hong, B. F.; Wu, B. H.; Yang, S. Y.; Horng, H. E.; Yang, H. C.; Tseng, W. Y. Isaac; Tseng, W. K.; Liu, Y. B.; Lin, L. C.; Lu, L. S.; Lee, Y. H.

    2007-01-01

    In this work, the authors used a superconducting quantum interference device (SQUID) magnetocardiography (MCG) system consisted of 64-channel low-transition-temperature SQUID gradiometers to detect the MCG signals of hepercholesterolemic rabbits. In addition, the MCG signals were recorded before and after the injection of magnetic nanoparticles into the rabbits' ear veins to investigate the effects of magnetic nanoparticles on the MCG signals. These MCG data were compared to those of normal rabbits to reveal the feasibility for early detection of the electromagnetic changes induced by hypercholesterolemia using MCG with the assistance of magnetic nanoparticle injection.

  3. 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;

    2009-01-01

    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...... hemodynamic instability ensued in 3 patients. There were no clear predictors of VT/VF, and it is argued that prophylactic ICD implantation should be considered in patients supported with a continuous-flow LVAD....

  4. 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

    2015-10-01

    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.

  5. Fluoroscopy assisted tracheal intubation in a case of anticipated difficult airway: Fail safe devices can also fail

    OpenAIRE

    Appavoo Arulvelan; Madhusudhan Soumya; Kannath Santhosh

    2015-01-01

    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.

  6. Beneficial aspects of real time flow measurements for the management of acute right ventricular heart failure following continuous flow ventricular assist device implantation

    Directory of Open Access Journals (Sweden)

    Spiliopoulos Sotirios

    2012-11-01

    Full Text Available Abstract Background Optimal management of acute right heart failure following the implantation of a left ventricular assist device requires a reliable estimation of left ventricular preload and contractility. This is possible by real-time pump blood flow measurements. Clinical case We performed implantation of a continuous flow left ventricular assist device in a 66 years old female patient with an end-stage heart failure on the grounds of a dilated cardiomyopathy. Real-time pump blood flow was directly measured by an ultrasonic flow probe placed around the outflow graft. Diagnosis The progressive decline of real time flow and the loss of pulsatility were associated with an increase of central venous pressure, inotropic therapy and progressive renal failure suggesting the presence of an acute right heart failure. Diagnosis was validated by echocardiography and thermodilution measurements. Treatment Temporary mechanical circulatory support of the right ventricle was successfully performed. Real time flow measurement proved to be a useful tool for the diagnosis and ultimately for the management of right heart failure including the weaning from extracorporeal membrane oxygenation.

  7. 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

    2016-01-01

    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.

  8. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ziming, E-mail: wangziming@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ma Qiang [Chinese Academy of Inspection and Quarantine, Beijing 100123 (China); Lu Chunmei [College of Technology Center, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Dong Deming [College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer An absorbing microwave {mu}-SPE device packed with activated carbon was used. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to enrich the analytes. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to heat samples directly. Black-Right-Pointing-Pointer MAE-{mu}-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction ({mu}-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave {mu}-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in {mu}-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave {mu}-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 Degree-Sign C for 10 min. The extracts obtained by MAE-{mu}-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%.

  9. 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.

  10. Validation of the Greek version of the device subscale of the Quebec User Evaluation of Satisfaction with Assistive Technology 2.0 (QUEST 2.0).

    Science.gov (United States)

    Koumpouros, Yiannis; Karavasili, Alexandra; Papageorgiou, Effie; Siavelis, Panagiotis

    2016-01-01

    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.

  11. 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: subramanianb3@gmail.com [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)

    2014-01-25

    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}.

  12. Medical staff radiation exposure in electrophysiology procedures: First results during biventricular ICD implantation

    International Nuclear Information System (INIS)

    Cardiac resynchronization therapy (CRT) requires a very long fluoroscopy time due to the need to monitor the placement of the device and electrodes inside the patient’s body at every step of the procedure. Aim of this study was to analyse staff X-ray exposure during the intervention, measuring Hp(10) values with electronic dosimeters worn by medical staff. The scattered X-ray field was characterized using a spectrometric CdTe (cadmium-telluride) detector to define the radiation field impinging on the operator and thereby identify the correct dosimeter position for accurate measurement (i.e., above or under the shielding apron). In particular, knowledge of the X-ray spectrum yields information on photon flux and the energy distribution of the X-rays. Dosimetric data were then recorded in a series of 20 consecutive patients, obtaining a first set of Hp(10) data that can be used to estimate the risk for the electrophysiologist performing this procedure.

  13. Ultra-thin titanium nanolayers for plasmon-assisted enhancement of bioluminescence of chloroplast in biological light emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Hsun Su, Yen [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Hsu, Chia-Yun; Chang, Chung-Chien [Science and Technology of Accelerator Light Source, Hsinchu 300, Taiwan (China); Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Tu, Sheng-Lung; Shen, Yun-Hwei [Department of Resource Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2013-08-05

    Ultra-thin titanium films were deposited via ultra-high vacuum ion beam sputter deposition. Since the asymmetric electric field of the metal foil plane matches the B-band absorption of chlorophyll a, the ultra-thin titanium nanolayers were able to generate surface plasmon resonance, thus enhancing the photoluminescence of chlorophyll a. Because the density of the states of plasmon resonance increases, the enhancement of photoluminescence also rises. Due to the biocompatibility and inexpensiveness of titanium, it can be utilized to enhance the bioluminescence of chloroplast in biological light emitting devices, bio-laser, and biophotonics.

  14. A laser-assisted process to produce patterned growth of vertically aligned nanowire arrays for monolithic microwave integrated devices

    Science.gov (United States)

    Van Kerckhoven, Vivien; Piraux, Luc; Huynen, Isabelle

    2016-06-01

    An experimental process for the fabrication of microwave devices made of nanowire arrays embedded in a dielectric template is presented. A pulse laser process is used to produce a patterned surface mask on alumina templates, defining precisely the wire growing areas during electroplating. This technique makes it possible to finely position multiple nanowire arrays in the template, as well as produce large areas and complex structures, combining transmission line sections with various nanowire heights. The efficiency of this process is demonstrated through the realisation of a microstrip electromagnetic band-gap filter and a substrate-integrated waveguide.

  15. Ultra-thin titanium nanolayers for plasmon-assisted enhancement of bioluminescence of chloroplast in biological light emitting devices

    International Nuclear Information System (INIS)

    Ultra-thin titanium films were deposited via ultra-high vacuum ion beam sputter deposition. Since the asymmetric electric field of the metal foil plane matches the B-band absorption of chlorophyll a, the ultra-thin titanium nanolayers were able to generate surface plasmon resonance, thus enhancing the photoluminescence of chlorophyll a. Because the density of the states of plasmon resonance increases, the enhancement of photoluminescence also rises. Due to the biocompatibility and inexpensiveness of titanium, it can be utilized to enhance the bioluminescence of chloroplast in biological light emitting devices, bio-laser, and biophotonics

  16. 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

    2014-01-01

    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.

  17. Intervention for advanced heart failure patients and their caregivers to support shared decision-making about implantation of a ventricular assist device.

    Science.gov (United States)

    Gauthier, Marie-Andrée; Cossette, Sylvie; Ouimette, Marie-France; Harris, Virginie

    2016-01-01

    This project aimed to co-develop and pilot an intervention plan to support shared decision-making (SDM) for patients considering a ventricular assist device (VAD), their caregivers and the health care team. The project involved a focus group with patients and caregivers to explore their decision-making needs along with regular participation in team meetings resulting in the creation of a decision aid. The decision aid answered needs expressed by patients and caregivers, as well as the team's initial needsfor informational support, optimization of information exchange and process standardization. A workshop on SDM was also conducted to increase competence toward this approach and the use of the decision aid. This project is timely and relevant given the increase in VAD implantation in Canada. The intervention could also be applicable to other decision-making situations in which active participation can improve the quality of the decision process. PMID:27382666

  18. To move as a human. Comment on "The embodiment of assistive devices-from wheelchair to exoskeleton" by M. Pazzaglia and M. Molinari

    Science.gov (United States)

    Papadimitriou, Christina

    2016-03-01

    I agree with the authors, that "there have been very few attempts to develop user-centered medical technologies" [1] in the field of rehabilitation for persons with disabilities and wheelchair users in particular. The human-environment context in which humans plan and inhabit their actions as wheelchair users has not been extensively studied. The authors' unique work explores how a person embodies an exoskeleton (robotic legs or a wheelchair) in their everyday life and focuses on proprioception and brain's capacity to enlarge one's body schema in order to understand users' perspectives. Ultimately, Pazzaglia and Molinari wish to support persons who use assistive devices adapt and have successful, meaningful lives. The work is neuro-scientifically grounded, but doesn't forget the emotional or affective aspects of the user.

  19. A new simple and fast thermally-solvent assisted method to bond PMMA–PMMA in micro-fluidics devices

    Science.gov (United States)

    Bamshad, Arshya; Nikfarjam, Alireza; Khaleghi, Hossein

    2016-06-01

    A rapid and simple thermally-solvent assisted method of bonding was introduced for poly(methyl methacrylate) (PMMA) based microfluidic substrates. The technique is a low-temperature (68 {}^\\circ \\text{C} ), and rapid (15 \\min ) bonding technique; in addition, only a fan-assisted oven with some paper clamps are used. Two different solvents (ethanol and isopropyl alcohol) with two different methods of cooling (one-step and three steps) were employed to determine the best solvent and method of cooling (residual stresses may be released in different cooling methods) by considering bonding strength and quality. In this bonding technique, a thin film of solvent between two PMMA sheets disperses tends to dissolve a thin film of PMMA sheet surface, then evaporate, and finally reconnect monomers of the PMMA sheets at the specific operating temperature. The operating temperature of this method comes from the coincidence of the solubility parameter graph of PMMA with the solubility parameter graph of the solvents. Different tests such as tensile strength test, deformation test, leakage tests, and surface characteristics tests were performed to find the optimum conditions for this bonding strategy. The best bonding quality and the highest bonding strength (28.47 \\text{MPa} ) occurred when 70% isopropyl alcohol solution was employed with the one-step cooling method. Furthermore, the bonding reversibility was taken into account and critical percentages for irreversible bonding were obtained for both of the solvents and methods. This method provides a perfect bonding quality for PMMA substrates, and can be used in laboratories without needing any expensive and special instruments, because of its merits such as lower bonding time, lower-cost, and higher strength etc in comparison with the majority of other common bonding techniques.

  20. 我国智能辅助器具科技创新的现状与发展①%Invention of Intelligent Assistive Devices in China:Today and Future

    Institute of Scientific and Technical Information of China (English)

    张晓玉

    2013-01-01

    This paper introduced the concepts of intelligent assistive devices, and their development in China, including the intelligent prosthetics, wheelchairs, mobility assistive device, intelligent home and environment control, living assistion, and rehabilitation training ro-bot. There is a large gap in both intelligent assistive produces and services, and the technology is far away from the international advance.%  本文介绍智能辅具的基本概念及我国研发的智能辅具,包括智能假肢、智能轮椅、智能移动辅具、智能家居与环境控制辅具、智能生活辅具、智能康复训练机器人。我国的智能辅具与国际发展前沿存在着较大的差距。

  1. Captured Macro-embolus of Fractured Atheromatous Plaque by the Embolic Protection Device during Carotid Stent Assisted Angioplasty.

    Science.gov (United States)

    Kim, Mun Chul; Bennett, Shelby; Farb, Richard; Croul, Sydney; Lee, Seon-Kyu

    2013-02-01

    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.

  2. A phase separation method for analyses of fluoroquinones in meats based on ultrasound-assisted salt-induced liquid-liquid microextraction and a new integrated device.

    Science.gov (United States)

    Wang, Huili; Gao, Ming; Xu, Youqu; Wang, Wenwei; Zheng, Lian; Dahlgren, Randy A; Wang, Xuedong

    2015-08-01

    Herein, we developed a novel integrated device to perform phase separation based on ultrasound-assisted, salt-induced, liquid-liquid microextraction for determination of five fluoroquinones in meats by HPLC analysis. The novel integrated device consisted of three simple HDPE (high density polyethylene) parts that were used to separate the solvent from the aqueous solution prior to retrieving the extractant. The extraction parameters were optimized using the response surface method based on central composite design: 589μL of acetone solvent, pH2.1, 4.1min extraction time and 3.5g of Na2SO4. The limits of detection were 0.056-0.64 μgkg(-1) and recoveries were 87.2-110.6% for the five fluoroquinones in muscle tissue from fish, chicken, pork and beef. This method is easily constructed from inexpensive materials, extraction efficiency is high, and the approach is compatible with HPLC analysis. Thus, it has excellent prospects for sample pre-treatment and analysis of fluoroquinones in meat samples. PMID:25885797

  3. A remote monitoring system for patients with implantable ventricular assist devices with a personal handy phone system.

    Science.gov (United States)

    Okamoto, E; Shimanaka, M; Suzuki, S; Baba, K; Mitamura, Y

    1999-01-01

    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.

  4. 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.

  5. A bi-ventricular cardiac atlas built from 1000+ high resolution MR images of healthy subjects and an analysis of shape and motion.

    Science.gov (United States)

    Bai, Wenjia; Shi, Wenzhe; de Marvao, Antonio; Dawes, Timothy J W; O'Regan, Declan P; Cook, Stuart A; Rueckert, Daniel

    2015-12-01

    Atlases encode valuable anatomical and functional information from a population. In this work, a bi-ventricular cardiac atlas was built from a unique data set, which consists of high resolution cardiac MR images of 1000+ normal subjects. Based on the atlas, statistical methods were used to study the variation of cardiac shapes and the distribution of cardiac motion across the spatio-temporal domain. We have shown how statistical parametric mapping (SPM) can be combined with a general linear model to study the impact of gender and age on regional myocardial wall thickness. Finally, we have also investigated the influence of the population size on atlas construction and atlas-based analysis. The high resolution atlas, the statistical models and the SPM method will benefit more studies on cardiac anatomy and function analysis in the future.

  6. 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

    2015-01-01

    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

  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;

    2011-01-01

    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...... 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...... 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. Relation Between Pressure and Volume Unloading During Ramp Testing in Patients Supported with a Continuous-Flow Left Ventricular Assist Device

    DEFF Research Database (Denmark)

    Jung, Mette H; Hassager, Christian; Balling, Louise;

    2015-01-01

    (ramp-base) and then went from 8,000 RPM (ramp-low) increasing by 400 RPM/5 minutes until reaching 12,000 RPM or suction/arrhythmic event (ramp-high). The study was finalized by a 25-Watt exercise test at two ramp steps. Ten patients with ramp-base of 9,300 ± 241 RPM (at which 3/10 had aortic valve......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...

  9. Ultrasonic Substrate Vibration-Assisted Drop Casting (SVADC) for the Fabrication of Photovoltaic Solar Cell Arrays and Thin-Film Devices

    Science.gov (United States)

    Eslamian, Morteza; Zabihi, Fatemeh

    2015-12-01

    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.

  10. The CentriMag centrifugal blood pump as a benchmark for in vitro testing of hemocompatibility in implantable ventricular assist devices.

    Science.gov (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

    2015-02-01

    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.

  11. 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.

    Science.gov (United States)

    Gu, Kaiyun; Gao, Bin; Chang, Yu; Zeng, Yi

    2016-01-01

    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. PMID:27363758

  12. Study of velocity and shear stress distributions in the impeller passages and the volute of a bio-centrifugal ventricular assist device.

    Science.gov (United States)

    Chua, Leok Poh; Ong, Kang Shiu; Song, Guoliang

    2008-05-01

    The velocity fields within the impeller passages of three different impellers of the Kyoto-NTN bio-centrifugal ventricular assist device are measured using laser Doppler velocimetry in this study. The 16 forward-swept-blade impeller has better performance than the 16 straight-blade and 8 backward-swept-blade impellers in terms of smooth flow pattern, and has less high-shear-stress regions in the passages. The flow distributions are found to be similar with those measured by Yu et al. Through-flow characteristics are found in the impeller when the passages open to the biggest volute space. The flow fields in the blade channels of the impeller were found to be axis symmetrical due to the double volute design with the objective of minimizing the imbalance of the radial thrust when the impeller is magnetically suspended. In addition, the high-intensity vortex which was detected by Yu et al. at the discharge channel of the pump is effectively reduced when the end of the splitter plate is modified by increasing the taper ratio from 4 to 20. The new design would reduce the hemolysis of blood due to the high shear rate of the vortex. PMID:18471167

  13. The CentriMag centrifugal blood pump as a benchmark for in vitro testing of hemocompatibility in implantable ventricular assist devices.

    Science.gov (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

    2015-02-01

    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. PMID:25066768

  14. Assistive Technology Based on Robotics and Rise in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaoyu; WANG Kaixuan

    2013-01-01

    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.

  15. Analysis of heat generation of lithium ion rechargeable batteries used in implantable battery systems for driving undulation pump ventricular assist device.

    Science.gov (United States)

    Okamoto, Eiji; Nakamura, Masatoshi; Akasaka, Yuhta; Inoue, Yusuke; Abe, Yusuke; Chinzei, Tsuneo; Saito, Itsuro; Isoyama, Takashi; Mochizuki, Shuichi; Imachi, Kou; Mitamura, Yoshinori

    2007-07-01

    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.

  16. Intra-abdominal hypertension due to heparin - induced retroperitoneal hematoma in patients with ventricle assist devices: report of four cases and review of the literature

    Directory of Open Access Journals (Sweden)

    Spiliopoulos Sotirios

    2010-11-01

    Full Text Available Abstract Introduction Elevated intra-abdominal pressure (IAP has been identified as a cascade of pathophysiologic changes leading in end-organ failure due to decreasing compliance of the abdomen and the development of abdomen compartment syndrome (ACS. Spontaneous retroperitoneal hematoma (SRH is a rare clinical entity seen almost exclusively in association with anticoagulation states, coagulopathies and hemodialysis; that may cause ACS among patients in the intensive care unit (ICU and if treated inappropriately represents a high mortality rate. Case Presentation We report four patients (a 36-year-old Caucasian female, a 59-year-old White-Asian male, a 64-year-old Caucasian female and a 61-year-old Caucasian female that developed an intra-abdominal hypertension due to heparin-induced retroperitoneal hematomas after implantation of ventricular assist devices because of heart failure. Three of the patients presented with dyspnea at rest, fatigue, pleura effusions in chest XR and increased heart rate although b-blocker therapy. A 36-year old female (the forth patient presented with sudden, severe shortness of breath at rest, 10 days after an "acute bronchitis". At the time of the event in all cases international normalized ratio (INR was Conclusion Identifying patients in the ICU at risk for developing ACS with constant surveillance can lead to prevention. ACS is the natural progression of pressure-induced end-organ changes and develops if IAP is not recognized and treated in a timely manner. Failure to recognize and appropriately treat ACS is fatal while timely intervention - if indicated - is associated with improvements in organ function and patient survival. Means for surgical decision making are based on clinical indicators of adverse physiology, rather than on a single measured parameter.

  17. Continuous-flow left ventricular assist device therapy in patients with preoperative hepatic failure: are we pushing the limits too far?

    Science.gov (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

    2015-04-01

    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."

  18. 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

    2014-01-01

    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

  19. Normalisation of left ventricular systolic function after change from VVI pacing to biventricular pacing in a child with congenital complete atrioventricular block, long-QT syndrome, and congenital muscular dystrophy

    DEFF Research Database (Denmark)

    Ellesøe, Sabrina G; Reimers, Jesper I; Andersen, Henrik

    2013-01-01

    Development of dilated cardiomyopathy in patients with congenital complete atrioventricular block with or without pacemaker is well described. We report a case of dilated cardiomyopathy in a child with congenital complete atrioventricular block, long-QT syndrome, and VVI pacemaker. Temporary paci...... in the right ventricular outflow tract demonstrated a 63% increase in cardiac output. After change to biventricular DDD pacing, left ventricular systolic function and diastolic dimensions normalised....

  20. Ross-Konno and Endocardial Fibroelastosis Resection After Hybrid Stage I Palliation in Infancy: Successful Staged Left-Ventricular Rehabilitation and Conversion to Biventricular Circulation After Fetal Diagnosis of Aortic Stenosis

    OpenAIRE

    Moon-Grady, Anita J.; Moore, Phillip; Azakie, Anthony

    2010-01-01

    We report a patient who presented during fetal life with severe aortic stenosis, left-ventricular dysfunction, and endocardial fibroelastosis (evolving hypoplastic left heart syndrome). Management involved in utero and postnatal balloon aortic valvuloplasty for partial relief of obstruction and early postnatal hybrid stage I palliation until recovery of left-ventricular systolic function had occurred. The infant subsequently had successful conversion to a biventricular circulation by combinin...

  1. 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

    2011-12-01

    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

  2. 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

    2015-01-01

    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.

  3. Reverse left ventricular remodeling is more likely in non ischemic cardiomyopathy patients upgraded to biventricular stimulation after chronic right ventricular pacing

    Directory of Open Access Journals (Sweden)

    Morales Maria-Aurora

    2011-12-01

    Full Text Available Abstract Background Chronic right ventricular (RV apical pacing may lead to left ventricular (LV dyssynchrony and LV dysfunction. In heart failure due to RV pacing, upgrading to biventricular stimulation (CRT can improve NYHA Class and LV function. A proportion of patients do not respond to upgrading. Aim was to assess whether etiology of LV dysfunction accounts for responses to CRT in RV-paced patients. Methods Sixty-two patients treated by CRT, under RV pacing from 50.2 ± 5.4 months, were studied. Cause of LV dysfunction was non-ischemic (NIC in 28 and ischemic cardiomyopathy (IC in 34 patients. Clinical and conventional echocardiographic parameters were available within 1 month before RV pacing, within 1 month before CRT and at 12 ± 2 months of follow-up (FU. Results Decreased LVEF (from 37.0 ± 8.8 to 25.6 ± 6.1%, p 10% decrease in LVESD was observed in 24 patients: 5 with IC, 19 with NIC (p 10% decrease in LVESD remained highly significant (p Conclusions CRT improves functional class even after long-lasting pacing. Reverse remodeling is evident in a small population, more likely with NIC.

  4. 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

    2012-01-01

    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

  5. How Should Pushing Off or the Use of Assistive Devices Be Incorporated in the Timed Up and Go for Persons With Parkinson Disease?

    NARCIS (Netherlands)

    Stegemoller, E.L.; Schmidt, P.; Hass, C.; Malaty, I.; Okun, M.S.; Bloem, B.R.

    2015-01-01

    OBJECTIVES: 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 dis

  6. The cardiac implantable electronic device power source: evolution and revolution.

    Science.gov (United States)

    Mond, Harry G; Freitag, Gary

    2014-12-01

    Although the first power source for an implantable pacemaker was a rechargeable nickel-cadmium battery, it was rapidly replaced by an unreliable short-life zinc-mercury cell. This sustained the small pacemaker industry until the early 1970s, when the lithium-iodine cell became the dominant power source for low voltage, microampere current, single- and dual-chamber pacemakers. By the early 2000s, a number of significant advances were occurring with pacemaker technology which necessitated that the power source should now provide milliampere current for data logging, telemetric communication, and programming, as well as powering more complicated pacing devices such as biventricular pacemakers, treatment or prevention of atrial tachyarrhythmias, and the integration of innovative physiologic sensors. Because the current delivery of the lithium-iodine battery was inadequate for these functions, other lithium anode chemistries that can provide medium power were introduced. These include lithium-carbon monofluoride, lithium-manganese dioxide, and lithium-silver vanadium oxide/carbon mono-fluoride hybrids. In the early 1980s, the first implantable defibrillators for high voltage therapy used a lithium-vanadium pentoxide battery. With the introduction of the implantable cardioverter defibrillator, the reliable lithium-silver vanadium oxide became the power source. More recently, because of the demands of biventricular pacing, data logging, and telemetry, lithium-manganese dioxide and the hybrid lithium-silver vanadium oxide/carbon mono-fluoride laminate have also been used. Today all cardiac implantable electronic devices are powered by lithium anode batteries. PMID:25387600

  7. Aspectos técnicos da cateterização do seio coronariano baseada no componente atrial do eletrograma intracavitário e anatomia radiológica durante o procedimento de implante de marcapasso biventricular Technical aspects of coronary sinus catheterization based on the atrial component of the intracavitary electrogram and radiological anatomy during the implantation procedure of a biventricular pacemaker

    Directory of Open Access Journals (Sweden)

    Fernando Sérgio Oliva de Souza

    2006-04-01

    Full Text Available OBJETIVO: Apresentar uma proposição técnica baseada na experiência de 130 implantes utilizando técnica simplificada para cateterização do seio coronariano, baseada no componente atrial do eletrograma intracavi-tário e anatomia radiológica. MÉTODOS: De outubro de 2001 a outubro de 2004 foram realiza-dos 130 implantes de marcapasso biventricular, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, com prioridade ao componente atrial. RESULTADOS: O implante do sistema, utilizando-se a estimulação do ventrículo esquerdo via seio coronariano, não foi possível em 8 pacientes. Em 12 pacientes foram observadas dificuldades na canulação do óstio coronário e em 15 pacientes observaram-se dificuldades de progressão do eletrodo através do seio coronariano. O tempo médio de utilização de radioscopia foi de 18,69 min. CONCLUSÃO: A técnica de implante, utilizando a morfologia do componente atrial do eletrograma intracavitário e anatomia radiológica, demonstrou ser pouco trabalhosa, segura e eficaz para canulação do óstio do seio coronariano, necessitando de reduzido tempo de radioscopia.OBJECTIVE: To present a technical proposal based on the experience of 130 implantations using a simplified technique for coronary sinus catheterization, based on the atrial component of the intracavitary electrogram and radiological anatomy. METHODS: From October, 2001 to October, 2004, 130 biventricular pacemaker implantations were performed, using radiological anatomy and observation of the intracavitary electrogram, focusing on the atrial component. RESULTS: The implantation of the system using left ventricular pacing via coronary sinus was not possible in 8 patients. Difficulties on the cannulation of the coronary ostium were felt in 12 patients and difficulties of lead advancement through the coronary sinus were felt in 15 patients. The mean time of radioscopy utilization was 18.69 min. CONCLUSION: The

  8. Assistive technologies for the interaction of the elderly the development of a communication device for the elderly with complementing illustrations and examples

    CERN Document Server

    2014-01-01

    This book presents a wealth of insights and new conceptualizations for the development of Assistive Technologies for the Interaction of the Elderly. The book arranges the chapters according to important aspects of maximizing the use value in innovation projects. Every chapter will include an executive summary reporting the main results, a storyline using everyday language, and scientific excursions, wherever useful. The book shows how an innovation project should be structured towards maximum use value and how a project should be structured in order to make a difference. It describes the useful categorization of the large group of the elderly to maximize the focus of the innovation and demonstrates the user involvement into innovation activities. Of course, the assessment of such innovative projects is discussed as well as the “lessons learned”. The book also explores the business opportunities and the financial evaluation of aspects of assistive technology.  

  9. Is Implantation of a Left Ventricular Assist Device in Patients With Critical or Impending Cardiogenic Shock an Absolute Contraindication? Looking Back at Our Past Experience Trying to Identify Contraindicative Risk Factors.

    Science.gov (United States)

    Dell'Aquila, Angelo Maria; Schneider, Stefan R B; Risso, Paolo; Welp, Henryk; Glockner, David G; Alles, Sebastian; Sindermann, Jürgen R; Scherer, Mirela

    2015-12-01

    Poor survival has been demonstrated after ventricular assist device (VAD) implantation for Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1 and 2 patients compared with more stable levels. However, risk factors within this high-risk cohort have not been determined so far. The aim of the present study was to identify risk factors associated with this very high mortality rate. Between February 1993 and January 2013, 298 patients underwent VAD implantation in our institution. One hundred nine patients were in INTERMACS level 1 and 49 patients were in INTERMACS level 2 and were therefore defined as hemodynamically critical (overall 158 patients). Assist devices implanted were: HVAD HeartWare n = 18; Incor n = 11; VentrAssist n = 2; DeBakey n = 22; and pulsatile systems n = 105. After cumulative support duration of 815.35 months, Kaplan-Meier analysis revealed a survival of 63.9, 48.8, and 40.3% at 1, 6, and 12 months, respectively. Cox regression analyses identified age > 50 (P = 0.001, odds ratio [OR] 2.48), white blood cell count > 13.000/μL (P = 0.01, OR 2.06), preoperative renal replacement therapy (P = 0.001, OR 2.63), and postcardiotomy failure (P < 0.001, OR 2.79) as independent predictors of mortality. Of note, last generation VADs were not associated with significantly better 6-month survival (P = 0.59). Patients without the aforementioned risk factors could yield a survival of 79.2% at 6 months. This single-center experience shows that VAD implantation in hemodynamically unstable patients generally results in poor early outcome, even in third-generation pumps. However, avoiding the aforementioned risk factors could result in improved outcome.

  10. Ablation of intervertebral discs in dogs using a MicroJet-assisted dye-enhanced injection device coupled with the diode laser

    Science.gov (United States)

    Bartels, Kenneth E.; Henry, George A.; Dickey, D. Thomas; Stair, Ernest L.; Powell, Ronald; Schafer, Steven A.; Nordquist, Robert E.; Frederickson, Christopher J.; Hayes, Donald J.; Wallace, David B.

    1998-07-01

    Use of holmium laser energy for vaporization/coagulation of the nucleus pulposus in canine intervertebral discs has been previously reported and is currently being applied clinically in veterinary medicine. The procedure was originally developed in the canine model and intended for potential human use. Since the pulsed (15 Hz) holmium laser energy exerts photomechanical and photothermal effects, the potential for extrusion of additional disc material to the detriment of the patient is possible using the procedure developed for the dog. To reduce this potential complication, use of diode laser (805 nm - CW mode) energy, coupled with indocyanine green (ICG) as a selective laser energy absorber, was formulated as a possible alternative. Delivery of the ICG and diode laser energy was through a MicroJet device that could dispense dye interactively between individual laser 'shots.' Results have shown that it is possible to selectively ablate nucleus pulposus in the canine model using the device described. Acute observations (gross and histopathologic) illustrate that accurate placement of the spinal needle before introduction of the MicroJet device is critically dependent on the expertise of the interventional radiologist. In addition, the success of the overall technique depends on consistent delivery of both ICG and diode laser energy. Minimizing tissue carbonization on the tip of the MicroJet device is also of crucial importance for effective application of the technique in clinical veterinary medicine.

  11. Shadow mask assisted direct growth of ZnO nanowires as a sensing medium for surface acoustic wave devices using a thermal evaporation method

    International Nuclear Information System (INIS)

    Zinc oxide (ZnO) nanowires were directly synthesized on high temperature stable one-port surface acoustic wave (SAW) resonators made of LiNbO3 substrate and Pt/Ti electrodes using a self-seeding catalyst-free thermal evaporation method. To enhance post-growth device functionality, one half of an SAW resonator was masked along the interdigital transducer aperture length during the nanowire growth process using a stainless steel shadow mask, while the other half was used as the ZnO nanowire growth site. This was achieved by employing a precisely machined stainless steel sleeve to house the chip and mask in the reaction chamber during the nanowire growth process. The ZnO nanowire integrated SAW resonator exhibited ultraviolet radiation sensing abilities which indicated that the ZnO nanowires grown on the SAW device were able to interact with SAW propagation on the substrate even after the device was exposed to extremely harsh conditions during the nanowire growth process. The use of a thermal evaporation method, instead of the conventionally used solution-grown method for direct growth of ZnO nanowires on SAW devices, paves the way for future methods aimed at the fabrication of highly sensitive ZnO nanowire-LiNbO3 based SAW sensors utilizing coupled resonance phenomenon at the nanoscale. (paper)

  12. Technology of ferroelectric thin-film formation with large coercive field on amorphous SiO2 by ion-bombardment-assisted sputtering and oxygen radical treatment for future scaling down of ferroelectric gate field-effect transistor memory device

    International Nuclear Information System (INIS)

    Sr2(Ta1-x,Nbx)2O7 (perovskite STN; x=0.3) is one of the most practical candidates for one-transistor-type ferroelectric memory devices, because it has a low dielectric constant. However, in the application to metal-ferroelectric-insulator-Si field-effect transistor (MFIS-FET) memory devices, the fabrication of STN on an amorphous insulator, such as SiO2, is difficult. In particular, in the case of STN, because its crystallization annealing temperature is 950degC, the metal elements of STN and Si react with each other during crystallization annealing. As a result, perovskite STN cannot be fabricated. To overcome this problem, we have developed an ion-bombardment-assisted sputtering method. Furthermore, to obtain universal conditions for forming perovskite STN based on plasma physics, plasma parameters such as ion bombardment energy and ion flux, were measured. Perovskite STN was obtained when the ion bombardment energy was 38 eV and the normalized Kr ion flux was 78 [ions/atom]. An IrO2/STN (140 nm)/STN seed layer (10 nm)/Si device whose STN was fabricated under these plasma conditions, shows square hysteresis curves and a memory window of 1.7 V under an 8 V writing operation. This value corresponds to a coercive field of 55 kV/cm. (author)

  13. Ultrasonic Substrate Vibration-Assisted Drop Casting (SVADC) for the Fabrication of Photovoltaic Solar Cell Arrays and Thin-Film Devices

    OpenAIRE

    Eslamian, Morteza; Zabihi, Fatemeh

    2015-01-01

    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...

  14. 移动设备辅助日语听力自主学习的探究%Autonomous learning for Japanese listening assisted by mobile devices

    Institute of Scientific and Technical Information of China (English)

    管洁

    2016-01-01

    With the approach of the net era, the smart mobile devices are becoming more and more popular, how to use mobile devices to make learners study Japanese more efficiently at any time and place, especialy autonomous learning in Japanese listening wil become a new research subject. This paper is to discuss how the mobile devices aid the students’ autonomous learning of Japanese listening.%随着网络化时代的到来和智能移动设备日益普及,如何利用移动设备让学习者们随时随地进行高效率的日语学习,尤其是日语听力自主学习,将成为新的研究课题之一。本文就移动设备如何辅助日语听力自主学习而进行了相关阐述。

  15. 34 CFR 300.105 - Assistive technology.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Assistive technology. 300.105 Section 300.105 Education... DISABILITIES State Eligibility Other Fape Requirements § 300.105 Assistive technology. (a) Each public agency must ensure that assistive technology devices or assistive technology services, or both, as those...

  16. Cardiac resynchronization therapy: Dire need for targeted left ventricular lead placement and optimal device programming

    Institute of Scientific and Technical Information of China (English)

    Sokratis; Pastromas; Antonis; S; Manolis

    2014-01-01

    Cardiac resynchronization therapy(CRT) effected via biventricular pacing has been established as prime therapy for heart failure patients of New York Heart Association functional class Ⅱ, Ⅲ and ambulatory Ⅳ, reduced left ventricular(LV) function, and a widened QRS complex. CRT has been shown to improve symptoms, LV function, hospitalization rates, and survival. In order to maximize the benefit from CRT and reduce the number of non-responders, consideration should be given to target the optimal site for LV lead implantation away from myocardial scar and close to the latest LV site activation; and also to appropriately program the device paying particular attention to optimal atrioventricular and interventricular intervals. We herein review current data related to both optimal LV lead placement and device programming and their effects on CRT clinical outcomes.

  17. A Portable Device to Assist in the Harvest of Coffee in Colombia / Un Equipo Portátil para Asistir la Cosecha de Café en Colombia

    Directory of Open Access Journals (Sweden)

    Edilson León Moreno Cárdenas

    2015-01-01

    Full Text Available Abstract. The harvest is one of the most important activitiesin coffee crops; on the one hand, it provides employmentopportunities for a large group of rural workers and on the other,it supplies mature fruits for the production of high quality coffee.In the present study, a device was designed and evaluated to assistin manual coffee harvesting, called Alfa, which employs a threetoothedblade beater, a DC motor powered by dry batteries anda system for receiving detached fruits. The research proceeded intwo phases; in the first, the device was designed and built; in thesecond, an evaluation was carried out by using traditional manualcollection as a comparison. The evaluations were developed infour locations: three experimental stations of Cenicafé and oneprivate property. The variables studied were: number of fruits lefton the ground after harvest, percentage of immature coffee in theharvested mass and yield. The device presented an operating timeof four days without recharging, a weight less than four kg and anabsence of technical failures; the operators had no problems withits use; and, in addition, it was possible to increase the yield of theoperators by almost 70%; the percentage of immature coffee wasbetween 4.5% and 3% and losses were between one and 19 fruitsper site.  /  Resumen. La cosecha es una de las actividades más importantesen el cultivo de café; de un lado proporciona empleo a un ampliogrupo de trabajadores rurales y de otro brinda frutos madurosque contribuyen a la obtención de café de alta calidad. En lainvestigación un equipo llamado Alfa fue diseñado y evaluadopara asistir la cosecha manual del café. El equipo consistió de unimpactador de tres paletas dentadas, un motor DC accionado porbaterías secas y un sistema para recibir los frutos desprendidos.La investigación contó con dos fases; en la primera el equipofue diseñado y construido, en la segunda una evaluación fueadelantada empleando como comparación la

  18. Dynamics of three-dimensional radiative structures during RMP assisted detached plasmas on the large helical device and its comparison with EMC3-EIRENE modeling

    Science.gov (United States)

    Pandya, Shwetang N.; Peterson, Byron J.; Kobayashi, Masahiro; Ida, Katsumi; Mukai, Kiyofumi; Sano, Ryuichi; Miyazawa, Junichi; Tanaka, Hirohiko; Masuzaki, Suguru; Akiyama, Tsuyoshi; Motojima, Gen; Ohno, Noriyasu; LHD Experiment Group

    2016-04-01

    The resonant magnetic perturbation (RMP) island introduced in the stochastic edge of the large helical device (LHD) plasma plays an important role in the stabilization of the plasma detachment (Kobayashi et al 2013 Nucl. Fusion 53 093032). The plasma enters in the sustained detachment phase in the presence of an RMP once the line averaged density exceeds a critical value with a given input power. During detachment the enhanced radiation from the stochastic edge of the LHD undergoes several spatiotemporal changes which are studied quantitatively by an infrared imaging video bolometer (IRVB) diagnostic. The experimental results are compared qualitatively and quantitatively with the radiation predicted by the 3D transport simulation with fluid model, EMC3-EIRENE. A fair amount of qualitative agreement, before and after the detachment, is reported. The issue of overestimated radiation from the model is addressed by changing the free parameters in the EMC3-EIRENE code till the total radiation and the radiation profiles match closely, within a factor of two with the experimental observations. A better quantitative match between the model and the experiment is achieved at higher cross-field impurity diffusion coefficient and lower sputtering coefficient after the detachment. In this article a comparison, the first of its kind, is established between the quantified radiation from the experiments and the synthetic image obtained from the simulation code. This exercise is aimed towards validating the model assumptions against the experimentally measured radiation.

  19. Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device

    Directory of Open Access Journals (Sweden)

    Shawn Sanctis

    2015-03-01

    Full Text Available Tobacco mosaic virus (TMV has been employed as a robust functional template for the fabrication of a TMV/zinc oxide field effect transistor (FET. A microwave based approach, under mild conditions was employed to synthesize stable zinc oxide (ZnO nanoparticles, employing a molecular precursor. Insightful studies of the decomposition of the precursor were done using NMR spectroscopy and material characterization of the hybrid material derived from the decomposition was achieved using dynamic light scattering (DLS, transmission electron microscopy (TEM, grazing incidence X-ray diffractometry (GI-XRD and atomic force microscopy (AFM. TEM and DLS data confirm the formation of crystalline ZnO nanoparticles tethered on top of the virus template. GI-XRD investigations exhibit an orientated nature of the deposited ZnO film along the c-axis. FET devices fabricated using the zinc oxide mineralized virus template material demonstrates an operational transistor performance which was achieved without any high-temperature post-processing steps. Moreover, a further improvement in FET performance was observed by adjusting an optimal layer thickness of the deposited ZnO on top of the TMV. Such a bio-inorganic nanocomposite semiconductor material accessible using a mild and straightforward microwave processing technique could open up new future avenues within the field of bio-electronics.

  20. Multijunction Capillary Isoelectric Focusing Device Combined with Online Membrane-Assisted Buffer Exchanger Enables Isoelectric Point Fractionation of Intact Human Plasma Proteins for Biomarker Discovery.

    Science.gov (United States)

    Pirmoradian, Mohammad; Astorga-Wells, Juan; Zubarev, Roman A

    2015-12-01

    Prefractionation of proteins is often employed to improve analysis specificity in proteomics. Prefractionation based on the isoelectric point (pI) is particularly attractive because pI is a well-defined parameter and it is orthogonal to hydrophobicity on which reversed-phase chromatography is based. However, direct capillary electrophoresis of blood proteins is challenging due to its high content of salts and charged small molecules. Here, we couple an online desalinator device to our multijunction capillary isoelectric focusing (MJ-CIEF) instrument and perform direct isoelectric separation of human blood plasma. In a proof-of-principle experiment, pooled samples of patients with progressive mild cognitive impairment and corresponding healthy controls were investigated. Injection of 3 μL of plasma containing over 100 μg of proteins into the desalinator was followed by pI fractionation with MJ-CIEF in less than 1 h. Shotgun proteomics of 12 collected fractions from each of the 5 replicates of pooled samples resulted in the identification and accurate quantification (median CV between the replicates is <4%) of nearly 365 protein groups from 4030 unique peptides (with <1% FDR for both peptides and proteins). The obtained results include several proteins previously reported as AD markers. The isoelectric point of each quantified protein was calculated using a set of 7 synthetic peptides spiked into the samples. Several proteins with a significant pI shift between their isoforms in the patient and control samples were identified. The presented method is straightforward, robust, and scalable; therefore, it can be used in both biological and clinical applications.

  1. Application of the assistive device for shimming of MR imaging for brachial plexus%匀场辅助装置在臂丛神经成像中的应用

    Institute of Scientific and Technical Information of China (English)

    李鹏; 吕发金; 勒都晓兰; 王筱璇

    2012-01-01

    Objective To explore the application value of the self-made assistive device for shimming on 3D Cube T2W sequence MR imaging for normal brachial plexus. Methods Thirty healthy volunteers underwent same MR scan twice with 3D Cube T2W sequence to obtain images of brachial plexus, and the assistive device was used in the second time. The signal of nerve, muscle and background noise was measured. Images were postprocessed with MIP and CPR, and then image quality was assessed. SNR and contrast-to-noise ratio (CNR) were calculated. Results Low signal artifact on neck and non-uniform fat suppression occurred on conventional images, and the image quality grade of brachial plexus at various anatomic levels (roots, interscalene area, costoclavicular space and axillary level) was 2. 38 ± 0. 64, 2. 45 ± 0. 53, 1. 73 ± 0. 66, 1. 95 ± 0. 53, respectively. Using the assistive device, the artifact on neck disappeared, and the effect of fat suppression was better than before. The image quality grade of various anatomic levels in brachial plexus was 3. 95 ± 0. 21, 3. 82 0. 39 , 3. 38 ± 0. 55, 1. 97 ± 0. 41, respectively, higher than conventional images in the level of roots, interscalene area, costoclavicular space (all P<0. 001). SNR and CNR of conventional images were 13. 14 ± 4. 37 and 6. 65 ± 2. 96, respectively. Using the assistive device, SNR and CNR of images was 15. 10 ± 5. 91 and 8. 03 ± 3. 63, higher than those of conventional images (both P<0. 05). Conclusion The assistive device for shimming can improve the uniformity of local magnetic field and image quality of brachial plexus on 3D Cube T2W sequence.%目的 探讨自制匀场辅助装置在3D Cube T2W序列正常臂丛神经成像中的应用价值.方法 采用相同参数对30名健康志愿者双侧臂丛神经进行2次斜冠状位3D Cube T2W序列扫描,第2次扫描时使用匀场辅助装置,测量神经、肌肉、背景噪声信号,并进行MIP、CPR等后处理和图像质量评级,计算神

  2. Biventricular MR volumetric analysis and MR flow quantification in the ascending aorta and pulmonary trunk for quantification of valvular regurgitation; Biventrikulaere MR-Volumetrie und MR-Flussmessungen in Aorta ascendens und Truncus pulmonalis zur Quantifizierung von Klappeninsuffizienzen

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.B. [Marburg Univ. (Germany). Abt. Strahlendiagnostik; Kluge, A.; Bachmann, G.F. [Diagnostische Radiologie, Kerckhoff-Klinik GmbH, Bad Nauheim (Germany)

    2004-03-01

    Purpose: To test the value of biventricular volumetric analysis and the combination of biventricular volumetric analysis with flow quantification in the ascending aorta (Ao) and pulmonary trunk (Pu) for quantification of regurgitation volume and cardiac function in valvular regurgitation (VR) according to location and presence of single or multivalvular disease. Materials and Methods: In 106 patients, the stroke volumes were assessed by measuring the biventricular volumes and the forward-stroke volumes in the great and small circulation by measuring the flow in the Ao and Pu. Valve regurgitation volumes and quotients were calculated for single and multivalvular disease and correlated with semiquantitative 2D-echocardiography (grade I-IV). For the assessment of the cardiac function in VR, the volumetric parameters of ejection fraction and end-diastolic (EDV) and end-systolic (ESV) volumes were determined. Results: The detection rate was 49% for left ventricular (LV) VR and 42% for right ventricular (RV) VR. Low LV VR and RV VR usually could not be detected quantitatively, with the detection rate improving with echocardiographically higher insufficiency grades. Quantitative MRI could detect a higher grade solitary aortic valve insufficiency ({>=}2) in 11 of 12 patients and higher grade mitral valve insufficiency in 4 of 10 patients. A significant increase in RV and LV ventricular EDV and ESV was seen more often with increased MR regurgitation volumes. Aortic stenosis did not interfere with flow measurements in the Ao. Conclusions: Biventricular volumetry combined with flow measurements in Ao and Pu is a robust, applicable and simple method to assess higher grade regurgitation volumes and the cardiac function in single and multivalvular regurgitation at different locations. It is an important application for the diagnosis of VR by MRI. [German] Ziel: Untersuchung der Wertigkeit der biventrikulaeren Volumetrie und der Kombination von biventrikulaerer Volumetrie und

  3. Assistive Technology and Mathematics Education

    Science.gov (United States)

    Akpan, Joseph P.; Beard, Lawrence A.

    2014-01-01

    Educators and caregivers now have the opportunity to individualize and differentiate instructions with many technological devices never before available. Assistive Technology is being introduced in the classroom at all levels as a tool for teachers to help deliver instruction to all students. Assistive Technology is widely used to ensure…

  4. Evaluation of acceptability and use of lockable storage devices for pesticides in Sri Lanka that might assist in prevention of self-poisoning

    Directory of Open Access Journals (Sweden)

    Harriss Louise

    2009-02-01

    , although there was some decline in the proper usage over time. A large-scale trial of lockable storage devices in farming households in rural areas as a means of prevention of suicide and accidental poisoning is now indicated.

  5. 植入型心室辅助装置溶血及可植入性实验%Hemolysis test and fit study of an implantable ventricular assist device

    Institute of Scientific and Technical Information of China (English)

    吴广辉; 蔺嫦燕; 陈琛; 侯晓彤; 李海洋

    2011-01-01

    Objective In this study, the stability, the hemocompatibility and the implantation possibility of a left ventricular assist device were evaluated. Methods First, the left ventricular assist device drove distilled water at room temperature for 30 days, and its stability was tested by the observation of the rotation speed and the current of the motor. Second, under the condition of 5 L/min and 100 mmHg, the in vitro hemolysis performance was evaluated with fresh sheep blood on a mock circulation loop and the standard hemolysis index NIH were measured. Finally, the implantation possibility of the blood pump were evaluated by in vivo animal test. The analog blood pump was implanted in the experimental animals' heart chamber and its implantation possibility was validated by comparing the preoperative and the postoperative chest X-ray of the experimental animals. Results Neither stuck nor leakage happened during the 30 days experiment; experimental results showed good hemolysis performance of the blood pump, the NIH value of the blood pump was (0.008 ±0.002)g/100 L; the blood pump did not squeeze the heart and its surrounding organs in all experimental animals, and it can be easily implanted in the heart chamber. Conclusion The results showed that the implantable ventricular assist device has good stability, hemocompatibility and implantation possibility.%目的 探讨植入型心室辅助装置稳定性、主体血泵溶血性能及可植入性.方法 首先,辅助装置在常温下连续驱动蒸馏水30 d,观察血泵转速、驱动电流等变化情况,测试其稳定性.同时,在流量5 L/min左右,出入口压差为100 mmHg情况下,心室辅助装置通过体外模拟循环实验台驱动羊血完成溶血性能测试,最后计算出血泵标准溶血指数(normal index of hematolysis,NIH).最后,将心室辅助装置模拟主体血泵植入实验动物体内,对比术前及术后胸片,检验植入血泵对实验动物心室及周围器官的影

  6. 上海市辅助器具适配对残疾人生活质量的影响分析%Effect of Assistive Device Adaption on Quality of Life of People with Disabilities

    Institute of Scientific and Technical Information of China (English)

    宋毓; 吕军; 季敏; 毕琪; 金荣; 虞慧炯; 许斌; 陈万春; 李衡; 陈刚

    2015-01-01

    目的:分析上海市辅助器具适配对残疾人生活质量的影响,为提高辅助器具适配效果提供依据。方法2011年9月利用SF-12量表普查上海市杨浦区、宝山区2010年度接受辅助器具适配的残疾人326名。结果辅助器具适配显著改善残疾人的生活质量(P<0.001)。残疾年限越短,躯体和心理健康的改善程度越大;家庭收入越低,心理健康改善程度越大。结论应构建早介入、常回访的辅助器具适配服务机制;重点关注贫困残疾人家庭;完善辅助器具适配对生活质量的效果评估。%Objective To analyze the effect of assistive device adaption on quality of life of people with disabilities in 2 districts in Shanghai. Methods A survey on disabled people's quality of life was conducted in 2 districts in Shanghai in September, 2011. A total of 326 people with disabilities completed the SF-12 Questionnaire. Results Assistive device adaption significantly improved their quality of life (P<0.001). The shorter the years of being disabled was, and the lower the income was, the better the improvement of physical health and psycho-logical health was. Conclusion An early-intervention and constant-revisit service system should be established. More attention should be paid to the low-income family which has disabled members. It is needed to improve the tools for assessment of quality of life of people with disabilities.

  7. Symptoms, Devices, Prevention, Research | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... please turn JavaScript on. Feature: Hearing Loss Symptoms, Devices, Prevention & Research Past Issues / Spring 2015 Table of ... severe blow to the head Loud noise Assistive Devices Hearing aids —Small electronic devices worn in or ...

  8. Assessment of Using Assistive Ambulatory Device among Older Adults in America%助行设备在美国老年人群中防跌倒作用的现状分析

    Institute of Scientific and Technical Information of China (English)

    邱启祥; 王小敏; 刘浩

    2014-01-01

    本文分析各种助行设备(AAD),包括助行器、助行车、手杖等对美国老年使用者姿态、步态的影响及其与跌倒的关系;分析了为什么即使有AAD的帮助,老年人跌倒现象还是频繁出现。提出要在社区医疗服务中对老年人AAD的使用情况进行评估,并向他们宣传和培训正确使用AAD的知识,以便帮助老年人合理地使用AAD,尽可能地避免跌倒的发生。%This paper analyzed the problems existing with the usage of assistive ambulatory devices (AADs) among older adults in America and proposed solutions to improve these problems. The effects of AADs-walker, rollator, and cane-on gait and posture of old-er adults were assessed. Also, the relationships between AAD usage, fall occurrence, and why older adults continue to fall despite use of AADs were analyzed. It was suggested that in order to prevent from falls among older adults in the community routine assessment and train-ing in correct AAD use should be performed.

  9. Model and Simulation of Control System of the Left Ventricular Assist Device%左心室辅助装置控制系统的建模与仿真

    Institute of Scientific and Technical Information of China (English)

    王芳群; 王志宾; 吴雯珏; 郝根; 温太阳

    2013-01-01

    The left ventricular assist device adopting the brushless DC motor was designed.The model built on the basis of the throbbing regular analysis of the natural heart was simulated with the traditional PID control to get the data of the speed deviation,the deviation rate of the speed and the speed in the feedback of the speed.Then these data are input into the adaptive neural fuzzy toolbox in MATLAB for training to design the fuzzy controller.The results show that the design of the trained fuzzy controller is simpler than the traditional PID controller,the response speed is faster and the robustness is better.%提出一种采用无刷直流电动机设计的左心室辅助装置,通过对自然心脏的搏动规律的分析进行建模仿真.先采用传统PID控制,获得速度环的偏差、偏差变化率以及转速的数据,然后将这些数据在MATLAB的自适应神经模糊工具箱进行训练来设计模糊控制器.结果表明:训练后得到的模糊控制器要比传统PID控制器设计简单,控制响应速度快,鲁棒性好.

  10. Hemodynamic support for cardiogenic shock: Percutaneous left ventricular assist devices%心原性休克的血流动力学支持——经皮左心室辅助装置

    Institute of Scientific and Technical Information of China (English)

    何国祥

    2013-01-01

    有效治疗心原性休克对于降低病死率非常重要.本文综述不同治疗方法的原理及其对心室压力-容量环面积和心室作功的影响、主动脉内球囊反搏的局限性、经皮左心室辅助装置的种类、作用机制及其优越性、临床应用疗效和适应证.%Summary Effective treatments for cardiogenic shock are very important to reduce mortality rate of the patients.This paper reviewed the principles of different treatment methods and their impact on cardiac pressurevolume loops area and ventricular work,limitation of intra-aortic balloon pump,and types,mechanism,advantages,clinical application effects and indications of percutaneous left ventricular assist devices.

  11. Assisted Living

    Science.gov (United States)

    ... overwhelming majority of residents are female. Assisted Living Philosophy The philosophy of assisted living is to provide personalized, resident ... loved ones to learn about the care provider philosophy . Freedom of Choice The most progressive state regulations ...

  12. Assistive Technology

    Science.gov (United States)

    ... Page Resize Text Printer Friendly Online Chat Assistive Technology Assistive technology (AT) is any service or tool that helps ... be difficult or impossible. For older adults, such technology may be a walker to improve mobility or ...

  13. Surgical Assisting

    Science.gov (United States)

    ... specific training over and above a degree in science, nursing, physician assisting, or another health profession. Prerequisites . Recommended eligibility requirements for admission into a surgical assisting program are: Bachelor of Science degree (or higher) Associate degree in an allied ...

  14. Speech Recognition on Mobile Devices

    DEFF Research Database (Denmark)

    Tan, Zheng-Hua; Lindberg, Børge

    2010-01-01

    The enthusiasm of deploying automatic speech recognition (ASR) on mobile devices is driven both by remarkable advances in ASR technology and by the demand for efficient user interfaces on such devices as mobile phones and personal digital assistants (PDAs). This chapter presents an overview of ASR...

  15. For What Conditions Are Assistive Devices Used?

    Science.gov (United States)

    ... blindness Mental illness, including anxiety disorders, mood disorders, eating disorders, and psychosis, for example, is also a disability. ... Home Contact Accessibility Web Policies and Notices FOIA Facebook Twitter Pinterest YouTube RSS NIH...Turning Discovery Into ...

  16. What Is a Ventricular Assist Device?

    Science.gov (United States)

    ... Trials Links Related Topics Heart Failure Heart Surgery Heart Transplant How the Heart Works Total Artificial Heart Send ... heart recovers. While you're waiting for a heart transplant . If you're not eligible for a heart ...

  17. Ball assisted device for analytical surface sampling

    Science.gov (United States)

    ElNaggar, Mariam S; Van Berkel, Gary J; Covey, Thomas R

    2015-11-03

    A system for sampling a surface includes a sampling probe having a housing and a socket, and a rolling sampling sphere within the socket. The housing has a sampling fluid supply conduit and a sampling fluid exhaust conduit. The sampling fluid supply conduit supplies sampling fluid to the sampling sphere. The sampling fluid exhaust conduit has an inlet opening for receiving sampling fluid carried from the surface by the sampling sphere. A surface sampling probe and a method for sampling a surface are also disclosed.

  18. 21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction micropipette fabrication... Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a) Identification. Assisted reproduction micropipette fabrication devices are instruments intended to pull, bevel, or forge...

  19. Estudo comparativo das estimulações ventricular direita e biventricular no pós-operatório de revascularização miocárdica

    Directory of Open Access Journals (Sweden)

    ALBUQUERQUE Luciano C.

    2002-01-01

    Full Text Available OBJETIVO: Nos anos recentes, a ressincronização ventricular tem sido proposta como adjuvante no tratamento da insuficiência cardíaca congestiva. O objetivo deste estudo é comparar as alterações eletrocardiográficas e o efeito hemodinâmico imediato das estimulações ventricular direita (EVD e biventricular (EBV, no pós-operatório de operação de revascularização miocárdica (CRM com circulação extracorpórea (CEC. CASUÍSTICA E MÉTODOS: Em um ensaio clínico cruzado, 13 pacientes com doença coronária multiarterial, e fração de ejeção inferior a 50%, foram submetidos a estimulação epicárdica temporária univentricular direita e biventricular, no 5° dia de pós-operatório. As variáveis analisadas foram duração do complexo QRS, dimensões do átrio esquerdo (AE e ventrículo esquerdo (VE, fração de encurtamento do VE (delta D e fração de ejeção do VE. Os grupos foram comparados através do teste de t de Student para amostras pareadas, considerando-se nível de significância de 0,05. RESULTADOS: A duração média do complexo QRS foi de 185±26 ms durante a EVD, e de 126±37 ms com a EBV (p<0,001. O diâmetro médio do AE com a EVD foi de 40±4 mm, e de 35±4 mm na EBV (p<0,001. As médias dos diâmetros diastólico e sistólico finais do VE foram, respectivamente, de 49±13 mm e 59±11 mm com a EVD, e de 42±12 mm e 52±10 mm durante a EBV (p<0,001. A delta D média do VE determinada pela EVD foi de 18±7%, e de 22±8% com a EBV (p=0,017. A fração de ejeção média do VE com a EVD foi de 33±14%, e de 46±17% durante a EBV (p<0,001. CONCLUSÃO: No modelo estudado, a estimulação biventricular temporária determinou melhora significativa do desempenho hemodinâmico, em comparação à estimulação ventricular direita, e um complexo QRS com duração próxima à fisiológica.

  20. Prognosis of hospital survivors after salvage from cardiopulmonary bypass with centrifugal cardiac assist.

    Science.gov (United States)

    Curtis, J J; Walls, J T; Schmaltz, R A; Boley, T; Landreneau, R; Nawarawong, W

    1990-01-01

    Since October 1986, 6 hospital survivors who were salvaged from cardiopulmonary bypass (CPB) with the Sarns centrifugal pump were observed. Centrifugal assist was employed only after failure to wean with usual resuscitative measures, including multiple high dose inotropes and intraaortic balloon pumping. There were five men and one woman, 46-59 years of age (mean 61 years). All patients had undergone coronary artery bypass grafting, with two patients having had concomitant left ventricular aneurysmectomy and two aortic valve replacement. Five patients had left ventricular assist only and one had biventricular assist. Duration of assist ranged from 26 to 72 hr (mean 48 hr). Complications were ubiquitous, and the resultant prolonged hospitalization was resource intensive. All hospital survivors remain alive and are in New York Heart Association functional Class II, with an average follow-up of 24 months, (6-41 months). Compared with preoperative values, current left ventricular function is improved in 2 patients, has deteriorated in 3, and is unchanged in 1. Thus, the Sarns centrifugal pump will allow salvage of some patients who otherwise are not weanable from CPB. Survivors can expect a reasonable functional capacity as reflected by this experience.

  1. Smart portable rehabilitation devices

    Directory of Open Access Journals (Sweden)

    Leahey Matt

    2005-07-01

    Full Text Available Abstract Background The majority of current portable orthotic devices and rehabilitative braces provide stability, apply precise pressure, or help maintain alignment of the joints with out the capability for real time monitoring of the patient's motions and forces and without the ability for real time adjustments of the applied forces and motions. Improved technology has allowed for advancements where these devices can be designed to apply a form of tension to resist motion of the joint. These devices induce quicker recovery and are more effective at restoring proper biomechanics and improving muscle function. However, their shortcoming is in their inability to be adjusted in real-time, which is the most ideal form of a device for rehabilitation. This introduces a second class of devices beyond passive orthotics. It is comprised of "active" or powered devices, and although more complicated in design, they are definitely the most versatile. An active or powered orthotic, usually employs some type of actuator(s. Methods In this paper we present several new advancements in the area of smart rehabilitation devices that have been developed by the Northeastern University Robotics and Mechatronics Laboratory. They are all compact, wearable and portable devices and boast re-programmable, real time computer controlled functions as the central theme behind their operation. The sensory information and computer control of the three described devices make for highly efficient and versatile systems that represent a whole new breed in wearable rehabilitation devices. Their applications range from active-assistive rehabilitation to resistance exercise and even have applications in gait training. The three devices described are: a transportable continuous passive motion elbow device, a wearable electro-rheological fluid based knee resistance device, and a wearable electrical stimulation and biofeedback knee device. Results Laboratory tests of the devices

  2. Study on an assistant intelligent device system model for vending machine%一种自动售货机辅助智能装置系统模型研究

    Institute of Scientific and Technical Information of China (English)

    张兰华; 杨德圣; 高庆月; 张国亮; 种法腾; 佟文平

    2012-01-01

    为了实现对自动售货机数据的查询与存取,增加其语音提示、屏幕显示及过期智能提示,提出了利用嵌入式的方式增加自动售货机辅助智能装置系统功能模块以及通过太阳能电路的方式改造照明功能,通过软件工程与面向对象的模块开发方式开发公共接口,对嵌入的功能模块进行分析与设计,实现了操作员简单对接、快速数据查询与存取,同时也为售货行为增强了安全性,操作更人性化.通过实践的调研及测试证实在现有的自动售货机上嵌入辅助功能模块是可行的、有效的.%In order to implement the data store and query in vending machine,add the voice hint, OSD and Intelligent hint for out of date,an assistant intelligent device system is present by the embedded technology and the lighting is transformed by the solar energy. With the software engineer and object-oriented a common interface is developed and the embedded module is analyzed and designed to achieve the data transmission,store and query quickly,at the same time the safety of the sale behaviour is enhanced with humanization of the operation.Through testing and practical investigating it is feasible and effective to embed auxiliary function module into the auto vending machine.

  3. Avaliar a correlação entre a concentração da hemoglobina e a medida ecográfica do diâmetro biventricular externo em fetos anêmicos de gestantes isoimunizadas

    Directory of Open Access Journals (Sweden)

    Rodrigues Rosangela Lopes Miranda

    2005-01-01

    Full Text Available OBJETIVO: Verificar se existe correlação significativa entre a medida ecográfica do diâmetro biventricular externo e a concentração sérica da hemoglobina fetal pré-transfusional e se essa medida ecográfica poderá vir a ser utilizada como marcador não invasivo da anemia fetal. MÉTODOS: Estudo transversal prospectivo, no qual foram selecionadas 65 cordocenteses realizadas em 36 fetos anêmicos de mães portadoras de isoimunização pelo fator Rh. Obteve-se a medida do diâmetro biventricular externo (DBVE, por meio do modo M, utilizando-se aparelho de ultra-som convencional. Anterior à transfusão foi obtida amostra de 0,5ml de sangue fetal, para dosagem da hemoglobina, sendo a medida imediatamente realizada através de espectrofotometria, no equipamento Hemocue®. Como análise estatística foi utilizada a regressão dos mínimos quadrados, aceitando-se p<0,05 e análise multivariada. RESULTADOS: Foram observadas correlação inversa entre a concentração da hemoglobina no sangue fetal no momento prévio à transfusão e a medida do DBVE e correlação direta entre a medida do DBVE e a idade gestacional, e, também, através da análise multivariada que, à medida que a concentração de hemoglobina fetal cai, o DBVE aumenta, independentemente da influência da idade gestacional nesse parâmetro. CONCLUSÃO: Existe correlação inversa entre a concentração da hemoglobina no sangue fetal e a medida do DBVE, independente da idade gestacional. Os achados sugerem que o DBVE poderá vir a ser um marcador ecográfico de predição do nível de hemoglobina de fetos de gestantes isoimunizadas.

  4. 完全性心内膜垫缺损合并右室双出口的双心室修复%Biventricular refair for endocardial cushion defects with double outlet right ventricle

    Institute of Scientific and Technical Information of China (English)

    李富骊; 尤斌; 李平; 郑铁; 许李力; 徐屹; 刘硕

    2011-01-01

    目的 总结完全性心内膜垫缺损合并右室双出口双心室修复的经验.方法 2006年7月至209年11月对6例完全性心内膜垫缺损合并右室双出口病人采用双片法修补完全性心内膜垫缺损,人工血管补片作右心室内隧道,连接室间隔缺损与主动脉口,引导左心室血经内隧道进入主动脉;应用牛心包补片扩大右室流出道;肺动脉瓣环小者用带瓣补片跨环修补右室流出道;心室内隧道有可能阻塞右室流出道造成重度梗阻者,右室流出道与主肺动脉之间安置带瓣管道(Rastelli手术).结果 术后死亡1例,占16.6%,其余病例恢复良好.结论 完全性心内膜垫缺损合并右室双出口一期双心室修复可获得良好效果.%Objective Double-outlet right ventricle,which often associated with total anomalous pulmonary venous connection and complete endocardial cushion defects,has been considered a risk factor for biventricular repair procedure.To reviewed cases treated by biventricular repair for endocardial cushion defects with double outlet right ventricle.Methods From July to November of 2009,6 patients (3 males and 3 females) aged from 7 to 24 (16.17±5.98) years and with endocardial cushion defects and double outlet right ventricle underwent operation of biventricular repair The duration of follow-up ranged from 10 days to 2 years(median,16 months).Endocardial cushion defects were repaired with a 2-patch technique.The artificial vascular patch was implanted to connect the ventricular septal defects and the aorta for draining the blood stream from the left ventricle to the aorta.The other patch was used to repair the ostium primum atrial septal defects.Right ventricular outflow tract obstructions was released and reconstructed by transplanting a bovine pericardium patch.If the size of pulmonary valve annulus was far more below the normal,a transannular pericardial patch was used.Rastelli procedure with a valved conduit between the right

  5. Review of "Handbook of Human Factors in Medical Device Design", edited by Matthew B. Weinger, Michael E. Wiklund and Daryle J. Gardner-Bonneau, Assistant Editor Loir M. Kelly

    Directory of Open Access Journals (Sweden)

    Gaev Jonathan A

    2011-06-01

    Full Text Available Abstract Human factors is the study of the relationship between people and devices or systems. The goal of considering human factors in the design of medical devices is to create devices that take into consideration the way people use technology and process information to create a man-machine interface that leads to the best possible performance. This text describes the significant aspects of human factors issues related to medical device design. It is well written and is useful for medical device designers and for others who use or evaluate medical equipment.

  6. IDEA. VOCES: A Mnemonic Device to Cue Mood Selection after Impersonal Expressions.

    Science.gov (United States)

    Chandler, Paul Michael

    1996-01-01

    Providing language learners with mnemonic devices assists retention and recall of vocabulary and structural items. This idea provides one such memory device to assist beginning and intermediate students who struggle with mood selection after impersonal expressions. (five references) (Author)

  7. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  8. Concentration device

    DEFF Research Database (Denmark)

    2013-01-01

    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  9. Study and Design of Multimedia Teaching Assistant Device Based on the RF Transmission%基于射频传输的多媒体教学辅助装置研究设计

    Institute of Scientific and Technical Information of China (English)

    郑立安; 龚杏雄; 牛昱光

    2013-01-01

    采用射频无线数据传输技术、USB接口技术、加速度传感技术以及PCM编码压缩技术,研究并设计了由手持端和接收端两部分构成的多媒体教学辅助装置.手持端具有无线话筒和鼠标左、右键功能,并利用教师手势和摇杆来实现操作屏幕光标的移动,采集到的声音数据和操作指令通过射频无线传送给接收端;接收端通过USB接口将数据和指令上传到PC机,驱动课堂多媒体设备来实现声音播放、课件演示以及教学软件操作,从而实现教师在课堂范围内远距离操作多媒体设备进行教学的功能.%This design uses RF wireless data transmission technology,USB interface technology,acceleration sensor technology as well as the PCM coding compression technology to study and design a multimedia teaching assistant device constituted by handheld end and the receiving end.The handheld terminal has the function of wireless microphone and mouse's left,right button,and can use teachers' gestures and joystick to operate the screen cursor moves,the voice data and operating commands collected by handheld terminal are transmitted to the receiving end via RF wireless.The data and commands are uploaded to the PC machine through the USB interface by receiving end,which drives class multimedia equipment to achieve the sound playback,courseware demonstration and operation of instruction software,that makes teachers achieve the long-distance operation of multimedia equipment for teaching in the range of classroom.

  10. Assisted Ventilation.

    Science.gov (United States)

    Dries, David J

    2016-01-01

    Controlled Mechanical Ventilation may be essential in the setting of severe respiratory failure but consequences to the patient including increased use of sedation and neuromuscular blockade may contribute to delirium, atelectasis, and diaphragm dysfunction. Assisted ventilation allows spontaneous breathing activity to restore physiological displacement of the diaphragm and recruit better perfused lung regions. Pressure Support Ventilation is the most frequently used mode of assisted mechanical ventilation. However, this mode continues to provide a monotonous pattern of support for respiration which is normally a dynamic process. Noisy Pressure Support Ventilation where tidal volume is varied randomly by the ventilator may improve ventilation and perfusion matching but the degree of support is still determined by the ventilator. Two more recent modes of ventilation, Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist (NAVA), allow patient determination of the pattern and depth of ventilation. Proposed advantages of Proportional Assist Ventilation and NAVA include decrease in patient ventilator asynchrony and improved adaptation of ventilator support to changing patient demand. Work of breathing can be normalized with these modes as well. To date, however, a clear pattern of clinical benefit has not been demonstrated. Existing challenges for both of the newer assist modes include monitoring patients with dynamic hyperinflation (auto-positive end expiratory pressure), obstructive lung disease, and air leaks in the ventilator system. NAVA is dependent on consistent transduction of diaphragm activity by an electrode system placed in the esophagus. Longevity of effective support with this technique is unclear. PMID:25501776

  11. Applications of multi-micro-volume pressure-assisted derivatization reaction device for analysis of polar heterocyclic aromatic amines by gas chromatography-mass spectrometry%耐压多样品微量衍生反应装置在气相色谱-质谱联用法分析极性杂环胺中的应用

    Institute of Scientific and Technical Information of China (English)

    王翊如; 陈方翔; 施雅梅; TAN Connieal; 陈曦

    2013-01-01

    A multi-micro-volume pressure-assisted derivatization reaction device has been designed and made for the silylation derivatization of polar heterocyclic aromatic amines by N-(tert-butyldimethylsilyl) -N-methyl-trifluoroacetamide ( MTBSTFA ) with 1% catalyst tert-butyldimethylchlorosilane (TBDMCS) at a high temperature. The tert-butyldimethylsilyl derivatives then could be automatically analyzed by gas chromatography-mass spectrometry. Using the pressure-assisted device, the silylation reaction may occur at a temperature higher than the boiling points of the reagents, and several micro-volume samples can be simultaneously pre-treated in the same device to shorten the sample-preparation time and to improve the repeatability. The derivatization conditions including the headspace volume of the vial, the evaporative surface area of the reagent, derivatization temperature and time have been discussed for the use of the pressure-assisted device. The experimental results proved that the device is an effective way for the simultaneous derivatization of several micro-volume samples at a high temperature. Compared with a common device, the derivative amounts were obviously increased when using the pressure-assisted device at 90 ℃. Quantitative derivatization can be achieved even at 150 ℃ while there was no common device could be applied at such a high temperature due to the heavy losses of reagents by evaporation. However, no obviously higher reaction speed has been observed in such a circumstance with a higher temperature and a higher pressure using the pressure-assisted device.%设计并制作了耐压多样品微量衍生反应装置.在该装置中采用N-(叔丁基二甲基硅烷基)-N-甲基三氟乙酰胺(MTBSTFA,含1%叔丁基二甲基氯硅烷)硅烷化试剂高温衍生极性杂环胺,衍生产物可以直接在气相色谱-质谱联用仪上分析.使用该装置,既可以在比试剂沸点高的温度下实现衍生反应,也可以实现多个微量样品

  12. Mechanical Blood Pumps for Cardiac Assistance

    OpenAIRE

    Akdis, M; Reul, H

    2005-01-01

    Cardiac assist devices are classified into the traditional engineering categories of displacement and rotary pumps. Clinical use and indications of the various pump categories are outlined and a detailed description of currently available systems is given. The first part deals with extracorporeal as well as implantable ventricular assist devices (VAD) of the displacement type and is followed by a section on current developments in the field of total artificial hearts (TAH). The second part co...

  13. Microfluidic Device

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2016-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  14. Computational Framework for Aerocapture Devices (Ballutes) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The individual software tools that make up the analytical capabilities for the design of entry vehicles using an aero-assist/aero-capture device have been fully...

  15. Development of brake assist system. Summary of hydraulic brake assist system; Brake assist system no kaihatsu. Ekiatsushiki brake assist system no gaiyo

    Energy Technology Data Exchange (ETDEWEB)

    Hara, M.; Ota, M.; Shimizu, S. [Toyota, Motor Corp., Aichi (Japan)

    1997-10-01

    We have already developed vacuum-booster-type Brake Assist System that supplies additional braking power when panic braking is recognized. We are convinced that the expansion of Brake Assist System will become more important issue in the future. Therefore we have developed hydraulic Brake Assist System with increasing its controllability and reducing its discomfort. This system have a brake pressure sensor to detect emergency braking operation and an antilock device to supply additional braking power. 8 refs., 11 figs.

  16. Hearing Assistive Technology

    Science.gov (United States)

    ... for the Public / Hearing and Balance Hearing Assistive Technology Hearing Assistive Technology: FM Systems | Infrared Systems | Induction ... Assistive Technology Systems Solutions What are hearing assistive technology systems (HATS)? Hearing assistive technology systems (HATS) are ...

  17. Avaliação do desempenho hemodinâmico do dispositivo de assistência ventricular InCor como substituto do coração esquerdo Analysis of the hemodynamic performance of the InCor ventricular assist device as a substitute for the left heart

    Directory of Open Access Journals (Sweden)

    Anderson BENÍCIO

    1999-07-01

    dispositivo foi melhor quanto maior o nível de vácuo no sistema de drenagem e com a utilização de cânula ventricular.BACKGROUND: The mechanical circulatory assistance is a therapeutic option in cases of cardiogenic shock refractory to the pharmacological treatment, and is frequently used as a bridge for heart transplantation. OBJECTIVE: To evaluate the action of the Ventricular Assist Device (VAD developed by the Bioengineering Division of the Instituto do Coração, implanted as a substitute of the left heart. PATIENTS AND METHODS: Ten Girolando calves with medium weight of 73 kg were studied. The VAD-InCor implant was accomplished with the drainage cannula positioned in the left atrium (LA or in the apex of the left ventricle and the replacement cannula implanted in the descending thoracic aorta. The pressures of the right and left heart, cardiac output and the flow of VAD were determined before and after the pharmacological induction of myocardial failure, at different levels of vacuum of the drainage system. RESULTS: Values of the flow of VAD with the drainage in LA were of 2.2 ± 0.5 l/min without vacuum, of 3.7 ± 0.4 with vacuum of 10 mmHg, of 4.3 ± 0.4 with vacuum of 20 mmHg and of 4.8 ± 0.6 with vacuum of 30 mmHg. The values of the pressure of LA were: 11.7 ± 6; 9.8 ± 5.3; 8.5 ± 4.4 and 5.6 ± 3.3 mmHg under the same conditions, respectively. With the ventricular cannula, the VAD flow was 4.2 ± 0.6 without vacuum and of 4.4 ± 0.7 with vacuum of 10 mmHg, with of LA pressure of 11.1 ± 2 and 10.3 ± 3.5 mmHg in the two conditions. Those results were observed in similar hemodynamic conditions, with the VAD flow responsible for a greater percentile of the total cardiac output according to the level of vacuum. That percentile was of 86 ± 13% with the atrial cannula and vacuum of 30 mmHg and of 97 ± 3% with the ventricular drainage and vacuum of 10 mmHg. CONCLUSIONS: The VAD-InCor demonstrated its effectiveness as a substitute of the left heart. The

  18. ChinaHeart左心辅助装置的动物在体存活实验%In vivo Survival Evaluation of the ChinaHeart Left Ventricular Assist Device

    Institute of Scientific and Technical Information of China (English)

    刘修健; 吴广辉; 徐创业; 王璟; 侯晓彤; 李海洋; 杨朋; 渠文波; 蔺嫦燕

    2012-01-01

    验证磁悬浮离心式左心辅助装置—ChinaHeart VAD的在体血液相容性和可靠性,评估其对实验动物主要终末器官的影响.通过6例健康绵羊的在体存活实验进行评估.在心脏不停跳的情况下,装置入口插入左心尖,出口与降主动脉吻合.术前和术后做血常规、生化及血凝检查,术后连续监测动物存活及辅助装置运行状况.择期动物安乐死后,进行终末主要脏器的宏观和病理学检查.4只羊术后3 ~28 h内因麻醉或手术意外死亡;2只羊成功复苏并分别辅助20 d和38 d后施行安乐死.对于成功存活的2例实验动物,术后护理期间血常规、生化和血凝检查结果均在正常范围内,辅助装置无机械故障发生.尸检时1只羊(存活20 d)血泵泵体内发现一肉眼可见小块血栓沉积,其余无血栓形成;组织病理检查发现2只羊左肺贴近辅助装置部位均可见有小叶性肺炎,其余终末脏器无明显病变发生.ChinaHeart VAD在体辅助期间血液相容性能良好,对各主要终末脏器无显著影响,具有较好的可靠性;动物存活实验中麻醉呼吸管理和手术操作也至关重要.%An in vivo experimental investigation was performed in ovine model to evaluate hemocompatibility, reliability and end-organ effects of the ChinaHeart VAD, a magnetic left ventricular assist device. The device was implanted in 6 healthy male sheep. Under anesthesia, via left lateral thoracotomy, the inflow cannula was inserted into the left ventricular apex on beating hearts, and the outflow graft was anastomosed to the descending aorta. Routine hematologic and biochemical tests were performed preoperatively and postoperatively to evaluate peripheral organ functions. Pump operating parameters were recorded continuously until termination of the experiment. At the end of the experimental period the sheep was humanely killed, and the end-organs were examined macroscopically and histopathologically. Two of the

  19. Ferroelectric devices

    CERN Document Server

    Uchino, Kenji

    2009-01-01

    Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat

  20. Mobile Learning Devices. Essentials for Principals

    Science.gov (United States)

    Rogers, Kipp D.

    2011-01-01

    In "Mobile Learning Devices," the author helps educators confront and overcome their fears and doubts about using mobile learning devices (MLDs) such as cell phones, personal digital assistants, MP3 players, handheld games, digital audio players, and laptops in classrooms. School policies that ban such tools are outdated, the author suggests;…

  1. 10 CFR 34.46 - Supervision of radiographers' assistants.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Supervision of radiographers' assistants. 34.46 Section 34... radiographers' assistants. Whenever a radiographer's assistant uses radiographic exposure devices, associated... personal supervision of a radiographer. The personal supervision must include: (a) The...

  2. 21 CFR 884.6200 - Assisted reproduction laser system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction laser system. 884.6200... Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a device that images, targets, and controls the power and pulse duration of a laser beam used to ablate a...

  3. 14 CFR 382.125 - What procedures do carriers follow when wheelchairs, other mobility aids, and other assistive...

    Science.gov (United States)

    2010-01-01

    ... wheelchairs, other mobility aids, and other assistive devices must be stowed in the cargo compartment? 382.125... Wheelchairs, Other Mobility Aids, and Other Assistive Devices § 382.125 What procedures do carriers follow when wheelchairs, other mobility aids, and other assistive devices must be stowed in the...

  4. Orthotic devices using lightweight composite materials

    Science.gov (United States)

    Harrison, E., Jr.

    1983-01-01

    Potential applications of high strength, lightweight composite technology in the orthotic field were studied. Several devices were designed and fabricated using graphite-epoxy composite technology. Devices included shoe plates, assistive walker devices, and a Simes prosthesis reinforcement. Several other projects having medical application were investigated and evaluations were made of the potential for use of composite technology. A seat assembly was fabricated using sandwich construction techniques for the Total Wheelchair Project.

  5. Medical Device Development: the challenge for ergonomics

    OpenAIRE

    Jennifer L Martin; Norris, Beverley J.; Murphy, Elizabeth; Crowe, John A.

    2008-01-01

    High quality, well designed medical devices are necessary to provide safe and effective clinical care for patients as well as to ensure the health and safety of professional and lay device users. Capturing the user requirements of users and incorporating these into design is an essential component of this. The field of ergonomics has an opportunity to assist, not only with this area, but also to encourage a more general consideration of the user during medical device development. A review ...

  6. Study of hydrodynamic in vitro and animal experiment of a homebred pneumatic pulsatile ventricular assist device%国产气动搏动性心室辅助装置的体外流体力学及动物实验观察

    Institute of Scientific and Technical Information of China (English)

    史国宁; 陈庆良; 陈彤云; 刘建实

    2015-01-01

    目的:对我国自主研发气动搏动性心室辅助装置进行体外流体力学检验及活体动物应用实验,检验其是否满足临床心室辅助装置要求。方法通过体外模拟循环实验台,30%甘油水溶液作为循环介质,接入心室辅助装置,测定不同模式下血泵的后负荷和流量,以此检测装置的流体力学效果。对6只实验犬应用心室辅助装置左心辅助模式1 h,之后药物KCl诱颤心脏,5 min后除颤。监测心室辅助装置对实验犬的心率、血压支持效果。结果心室辅助装置流体力学实验后负荷100 mmHg条件下,流量可达到4 L/min以上。实验犬经左室安装辅助装置后,各时间点心率无明显变化。辅助后即刻与辅助前相比收缩压升高约30 mmHg,舒张压升高约19 mmHg。辅助过程中未见明显血压波动。诱颤后可维持收缩压60 mmHg,除颤后撤除装置存活良好。结论该心室辅助装置所产生的流体压力可基本满足临床心室辅助要求,短期应用于实验犬有效、安全、稳定,长期使用效果尚需进一步实验证明。%Objective To study in vitro hydrodynamics of a pneumatic pulsatile ventricular assist device developed ex⁃clusively by China, and establish an animal model for the detection by the device. Methods The hydromechanics experi⁃ment was performed on an in vitro test loop using MEDOS-System to drive the ventricular assist device, and lycerl-water so⁃lution was used as circulating medium. The changes of afterload pressure and the output of the pump were monitored, and the impermeability and stability were also assessed after the experiment. Six adult dogs were used as the experimental animals. The device worked in the left heart assistance mode for 1 hour then the ventricular fibrillation was induced by potassium chloride, and then defibrillated after 5 min while the device remained working. The hemodynamics data were monitored con⁃secutively during

  7. 国产气动搏动性心室辅助装置的体外流体力学及动物实验观察%Study of hydrodynamic in vitro and animal experiment of a homebred pneumatic pulsatile ventricular assist device

    Institute of Scientific and Technical Information of China (English)

    史国宁; 陈庆良; 陈彤云; 刘建实

    2015-01-01

    Objective To study in vitro hydrodynamics of a pneumatic pulsatile ventricular assist device developed ex⁃clusively by China, and establish an animal model for the detection by the device. Methods The hydromechanics experi⁃ment was performed on an in vitro test loop using MEDOS-System to drive the ventricular assist device, and lycerl-water so⁃lution was used as circulating medium. The changes of afterload pressure and the output of the pump were monitored, and the impermeability and stability were also assessed after the experiment. Six adult dogs were used as the experimental animals. The device worked in the left heart assistance mode for 1 hour then the ventricular fibrillation was induced by potassium chloride, and then defibrillated after 5 min while the device remained working. The hemodynamics data were monitored con⁃secutively during the trial. Results The ventricular assist device worked stably and reliably during the hemodynamic exper⁃iment. The pump can generate more than 4 L/min flow against the afterload pressure of 100 mmHg. There were no significant changes in heart rate at different time points in experimental dogs after left ventricular assist. Comparison between after auxil⁃iary immediately and former auxiliary, the diastolic blood pressure of dogs increased 30 mmHg with the ventricular assist, and the diastolic pressure increased 19 mmHg. No obvious fluctuation in blood pressure was found during the auxiliary pro⁃cess. The diastolic blood pressure stayed at 60 mmHg when the heart was in ventricular fibrillation, and returned to normal after electrical defibrillation. Conclusion The ventricular assist device works stably in vitro test, and the pump can meet the need of adult’s ventricular assist. It is effective and security to dogs in short term. The effects of long-term use need to be future proved.%目的:对我国自主研发气动搏动性心室辅助装置进行体外流体力学检验及活体动物应用实验,检验

  8. 21 CFR 884.6170 - Assisted reproduction water and water purification systems.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction water and water purification... Devices § 884.6170 Assisted reproduction water and water purification systems. (a) Identification. Assisted reproduction water purification systems are devices specifically intended to generate high...

  9. Laser assisted hair-removal.

    Science.gov (United States)

    Choudhary, S; Elsaie, M L; Nouri, K

    2009-10-01

    A number of lasers and light devices are now available for the treatment of unwanted hair. The goal of laser hair removal is to damage stem cells in the bulge of the hair follicle by targeting melanin, the endogenous chromophore for laser and light devices utilized to remove hair. The competing chromophores in the skin and hair, oxyhemoglobin and water, have a decreased absorption between 690 nm and 1000 nm, thus making this an ideal range for laser and light sources. Laser hair removal is achieved through follicular unit destruction based on selective photothermolysis. The principle of selective photothermolysis predicts that the thermal injury will be restricted to a given target if there is sufficient selective absorption of light and the pulse duration is shorter than the thermal relaxation time of the target. This review will focus on the mechanisms of laser assisted hair removal and provide an update on the newer technologies emerging in the field of lasers assisted hair removal.

  10. Separating device

    NARCIS (Netherlands)

    De Jong, T.P.R.

    2001-01-01

    A sorting device (1) suitable for sorting wire from a waste stream, comprising a body (2) that moves when in use, and provided with spikes or similar projections. The body is embodied as a rotatable roll (2), which oscillates axially during its rotation. The roll is coupled to an oscillation engine

  11. Printing Device

    NARCIS (Netherlands)

    Berg, van den M.J.; Markies, P.R.; Zuilhof, H.

    2014-01-01

    An ink jetprinting device includes a pressure chamber formed by a plurality of wall segments, a first aperture extending through a wall segment and communicating with an ink jet orifice and a second aperture extending through a wall segment and communicating with an ink supply duct. The pressure cha

  12. Electrochemical device

    Science.gov (United States)

    Grimes, Patrick G.; Einstein, Harry; Bellows, Richard J.

    1988-01-12

    A tunnel protected electrochemical device features channels fluidically communicating between manifold, tunnels and cells. The channels are designed to provide the most efficient use of auxiliary power. The channels have a greater hydraulic pressure drop and electrical resistance than the manifold. This will provide a design with the optimum auxiliary energy requirements.

  13. Stratification devices

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2008-01-01

    results in longer operation periods and improved utilization of the solar collector. Thermal stratification can be achieved, for example by using inlet stratification devices at all inlets to the storage tank. This paper presents how thermal stratification is established and utilized by means of inlet...

  14. Computer assisted uroflowmetry diagnostic system

    Science.gov (United States)

    Makal, Jarosław; Idźkowski, Adam; Walendziuk, Wojciech

    2006-10-01

    In this paper an original uroflowmeter (called Adalbertus) has been presented. The device draws the flow chart and measures the parameters of urine flow. It is used in urological surgeries as an assistance in diagnosis of lower urinary track diseases like Benign Prostatic Hyperplasia (BPH). The measuring track and its main part - weight sensor have been described. Also the way of uncertainty calculation is mentioned. An example flow chart has been shown and the achieved results have been compared with a commercial product.

  15. 28 CFR 0.86 - Seizure of gambling devices.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Seizure of gambling devices. 0.86 Section... Bureau of Investigation § 0.86 Seizure of gambling devices. The Director, Associate Director, Assistants... General to make seizures of gambling devices (18 U.S.C. 1955(d), 15 U.S.C. 1171 et seq.) and wire or...

  16. "Distinvar" device

    CERN Multimedia

    1965-01-01

    The alignment of one of the accelerator magnets being checked by the AR Division survey group. A "distinvar" device, invented by the group, using calibrated invar wires stretched between the fixed survey pillar (on the left) and a fixed point on the magnet. In two days it is thus possible to measure the alignment of the 100 magnets with an accuracy better than 1/10.

  17. Wiki keys on mobile devices

    OpenAIRE

    Weber, Gisela; Hagedorn, Gregor

    2010-01-01

    The development of increasingly powerful mobile devices like PDAs (Personal Digital Assistants) and Smartphones, with larger displays and greater resolution makes them increasingly suitable for identification tools available directly “in the field”. One of several approaches towards this aim in the KeyToNature project is based on wiki-stored documents. Important features of wiki-based keys, such as hidden text and media information as well as links to glossary entries are su...

  18. Biventricular Pacing Therapy for Heart Failure

    Institute of Scientific and Technical Information of China (English)

    Henry; Cheuk - Man Yu

    2001-01-01

    @@eart failure is a disease with high morbidity and mortality. It is also the commonest cause of medical ward admission. The incidence of heart failure has been increasing world-wide in the past decade.Studies observed that about 25 - 50 % of patients with heart failure had evidence of electromechanical delay,commonly in the form of left bundle branch block or intraventricular conduction delay on surface electrocardiogram. This condition results in dyssynchronous contraction, mitral regurgitation and was associated with a worse prognosis. These patients may therefore benefit from cardiac resynchronization therapy.

  19. Physician-Assisted Death

    OpenAIRE

    Senn, John S.

    1994-01-01

    Physician-assisted death includes both euthanasia and assistance in suicide. The CMA urges its members to adhere to the principles of palliative care. It does not support euthanasia and assisted suicide. The following policy summary includes definitions of euthanasia and assisted suicide, background information, basic ethical principles and physician concerns about legalization of physician-assisted death.

  20. Mechanical Blood Pumps for Cardiac Assistance

    Directory of Open Access Journals (Sweden)

    M. Akdis

    2005-01-01

    Full Text Available Cardiac assist devices are classified into the traditional engineering categories of displacement and rotary pumps. Clinical use and indications of the various pump categories are outlined and a detailed description of currently available systems is given. The first part deals with extracorporeal as well as implantable ventricular assist devices (VAD of the displacement type and is followed by a section on current developments in the field of total artificial hearts (TAH. The second part covers the rotary pump category from cardiopulmonary bypass applications to implantable systems, including specific design aspects of radial, diagonal, and axial pumps.

  1. Electrooptical devices

    Science.gov (United States)

    Hurwitz, C. E.

    1980-03-01

    This report covers work carried out with support of the Department of the Air Force during the period 1 October 1979 through 31 March 1980. A part of this support was provided by the Rome Air Development Center. CW operation at temperatures up to 55 C has been achieved for GaInAsP/InP double-heterostructure (DH) lasers emitting at 1.5 micrometers, which were grown without a GaInAsP buffer layer. These devices are of interest for use as sources in fiber-optics communications systems, since the lowest transmission loss reported for fused-silica optical fibers occurs at 1.55 micrometers. Surface passivation techniques developed for InP and GaInAsP avalanche photodiodes have resulted in reductions of dark current as large as four orders of magnitude, to values as low as .0000016 A/sq cm at 0.9 V(b) where V(b) is the breakdown voltage. Devices consisting entirely of InP have been passivated with plasma-deposited Si3N4, and those with a GaInAsP layer but with the p-n junction in InP have been passivated with polyimide. Neither of these techniques successfully reduces dark currents in devices with the p-n junction in the GaInAsP, but a film of photoresist sprayed with SF6 as the propellant has given excellent results. The electrical characteristics in InP ion implanted with Sn, Ge, Si, and C have been investigated. All of these column IV elements yielded n-type conductivity and Sn, Ge, and Si showed high electrical activation; however, implanted C was found to have a net electrical activation of only about 5 percent.

  2. DNA-Assisted β-phase Nucleation and Alignment of Molecular Dipoles in PVDF Film: A Realization of Self-Poled Bioinspired Flexible Polymer Nanogenerator for Portable Electronic Devices.

    Science.gov (United States)

    Tamang, Abiral; Ghosh, Sujoy Kumar; Garain, Samiran; Alam, Md Mehebub; Haeberle, Jörg; Henkel, Karsten; Schmeisser, Dieter; Mandal, Dipankar

    2015-08-01

    A flexible nanogenerator (NG) is fabricated with a poly(vinylidene fluoride) (PVDF) film, where deoxyribonucleic acid (DNA) is the agent for the electroactive β-phase nucleation. Denatured DNA is co-operating to align the molecular -CH2/-CF2 dipoles of PVDF causing piezoelectricity without electrical poling. The NG is capable of harvesting energy from a variety of easily accessible mechanical stress such as human touch, machine vibration, football juggling, and walking. The NG exhibits high piezoelectric energy conversion efficiency facilitating the instant turn-on of several green or blue light-emitting diodes. The generated energy can be used to charge capacitors providing a wide scope for the design of self-powered portable devices. PMID:26189605

  3. Scalable devices

    KAUST Repository

    Krüger, Jens J.

    2014-01-01

    In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.

  4. Thermonuclear device

    International Nuclear Information System (INIS)

    Purpose: To absorb fabrication errors in radial toroidal coils and a spacer and completely fill the gap between them by the provision of an expansion device between the coils and the supporting spacer by injecting fillers of a predetermined composition. Constitution: An expansion device comprising an expansion plate, packings inserted into grooves formed in the outer circumference of the expansion plate and a recessed pressure receiving plate is inserted between the wall surface of radial toroidal coils and a spacer for maintaining the gap between the toroidal coils. Then, filler comprising polyester resin and glass beads incorporated therein is injected from an injection aperture of the recessed pressure receiving plate having an exhaust aperture at the upper part. The filler is solidified and enables the fabrication error in the coils and the spacer to be absorbed. Since the gap between the coils and the spacer is completely filled, the tumbling force of the coils can surely be transmitted by way of the spacer to upper and lower racks. (Moriyama, K.)

  5. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  6. PLASMA DEVICE

    Science.gov (United States)

    Baker, W.R.

    1961-08-22

    A device is described for establishing and maintaining a high-energy, rotational plasma for use as a fast discharge capacitor. A disc-shaped, current- conducting plasma is formed in an axinl magnetic field and a crossed electric field, thereby creating rotational kinetic enengy in the plasma. Such energy stored in the rotation of the plasma disc is substantial and is convertible tc electrical energy by generator action in an output line electrically coupled to the plasma volume. Means are then provided for discharging the electrical energy into an external circuit coupled to the output line to produce a very large pulse having an extremely rapid rise time in the waveform thereof. (AE C)

  7. Single-arm, observational study of the ease of use of a redesigned pen device to deliver recombinant human follicle-stimulating hormone (follitropin alfa for assisted reproductive technology treatment

    Directory of Open Access Journals (Sweden)

    Illingworth PJ

    2014-06-01

    Full Text Available Peter J Illingworth,1 Robert Lahoud,1 Frank Quinn,1 Kendal Chidwick,2 Claire Wilkinson,2 Gavin Sacks1 1IVFAustralia, Greenwich, Sydney, NSW, Australia; 2Scientific Affairs, Merck Serono Australia Pty Ltd, Frenchs Forest, Sydney, NSW, Australia Purpose: Evaluation of patients’ ease of use of the redesigned, disposable, ready-to-use ­follitropin alfa pen during controlled ovarian stimulation for assisted reproductive technology. Methods: This single-center, observational, open-label, single-arm study recruited infertile normo-ovulatory women (aged 18–45 years. Nurses trained patients to self-administer recombinant human follicle-stimulating hormone daily using the follitropin alfa pen (300 IU, 450 IU, and 900 IU. Before treatment, patients completed Questionnaire A. Following self-administered treatment, on stimulation days 5–6 and 7–8 (within a day of receiving recombinant human chorionic gonadotropin, patients completed Questionnaire B. Nurses completed an ease-of-learning/teaching questionnaire. The primary endpoint was proportion of patients rating the pen as “easy/very easy” to use (Questionnaire B on the final visit before recombinant human chorionic gonadotropin. Secondary endpoints included: proportion of patients rating the follitropin alfa pen as easy to learn, use, prepare, deliver, and dispose of (Questionnaires A and B. Proportions (95% confidence intervals [CIs] were provided for primary and secondary endpoints. Adverse events were reported descriptively. Results: Eighty-six patients received recombinant human follicle-stimulating hormone. Of the 72 patients who had completed the overall assessment questions, 66 (91.7%; 95% CI =82.7%–96.9% found the pen “easy” to use. Also, 70/86 (81.4% patients “strongly agreed/agreed” that, overall, it was easy to learn how to use the pen; 72/86 (83.7% “strongly agreed/agreed” that easily understandable, verbal information was provided; and 70/86

  8. Carbon based prosthetic devices

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Carroll, D.W.; Barbero, R.S.; Archuleta, T. [Los Alamos National Lab., NM (US); Klawitter, J.J.; Ogilvie, W.; Strzepa, P. [Ascension Orthopedics (US); Cook, S.D. [Tulane Univ., New Orleans, LA (US). School of Medicine

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to evaluate the use of carbon/carbon-fiber-reinforced composites for use in endoprosthetic devices. The application of these materials for the metacarpophalangeal (MP) joints of the hand was investigated. Issues concerning mechanical properties, bone fixation, biocompatibility, and wear are discussed. A system consisting of fiber reinforced materials with a pyrolytic carbon matrix and diamond-like, carbon-coated wear surfaces was developed. Processes were developed for the chemical vapor infiltration (CVI) of pyrolytic carbon into porous fiber preforms with the ability to tailor the outer porosity of the device to provide a surface for bone in-growth. A method for coating diamond-like carbon (DLC) on the articulating surface by plasma-assisted chemical vapor deposition (CVD) was developed. Preliminary results on mechanical properties of the composite system are discussed and initial biocompatibility studies were performed.

  9. Experience with the Sarns centrifugal pump in postcardiotomy ventricular failure.

    Science.gov (United States)

    Curtis, J J; Walls, J T; Schmaltz, R; Boley, T M; Nawarawong, W; Landreneau, R J

    1992-09-01

    The reported clinical use of the Sarns centrifugal pump (Sarns, Inc./3M, Ann Arbor, Mich.) as a cardiac assist device for postcardiotomy ventricular failure is limited. During a 25-month period ending November 1988, we used 40 Sarns centrifugal pumps as univentricular or biventricular cardiac assist devices in 27 patients who could not be weaned from cardiopulmonary bypass despite maximal pharmacologic and intraaortic balloon support. Eighteen men and nine women with a mean age of 60.4 years (28 to 83) required assistance. Left ventricular assist alone was used in 12 patients, right ventricular assist in 2, and biventricular assist in 13. The duration of assist ranged from 2 to 434 hours (median 45). Centrifugal assist was successful in weaning 100% of the patients. Ten of 27 patients (37%) improved hemodynamically, allowing removal of the device(s), and 5 of 27 (18.5%) survived hospitalization. Survival of patients requiring left ventricular assist only was 33.3% (4/12). Complications were common and included renal failure, hemorrhage, coagulopathy, ventricular arrhythmias, sepsis, cerebrovascular accident, and wound infection. During 3560 centrifugal pump hours, no pump thrombosis was observed. The Sarns centrifugal pump is an effective assist device when used to salvage patients who otherwise cannot be weaned from cardiopulmonary bypass. Statistical analysis of preoperative patient characteristics, operative risk factors, and postoperative complications failed to predict which patients would be weaned from cardiac assist or which would survive.

  10. Assistive Technologies: A Lifeline for Learning

    Science.gov (United States)

    Conderman, Greg

    2015-01-01

    As students with disabilities increasingly are included into the general education classroom, teachers at all grade levels need to be knowledgeable about supports that promote student success. An assistive technology (AT) is any device or program that promotes the success of students with disabilities. This article provides an overview of ATs and…

  11. Evidence Considerations for Mobile Devices in the Occupational Therapy Process

    Directory of Open Access Journals (Sweden)

    Kelly Erickson

    2015-04-01

    Full Text Available Mobile app-based device utilization, including smartphones and handheld tablets, suggests a need to evaluate evidence to guide selection and implementation of these devices in the occupational therapy process. The purpose of the research was to explore the current body of evidence in relation to mobile app-based devices and to identify factors in the use of these devices throughout the occupational therapy process. Following review of available occupational therapy profession guidelines, assistive technology literature, and available mobile device research, practitioners using mobile app-based devices in occupational therapy should consider three areas: client needs, practitioner competence, and device factors. The purpose of this guideline is to identify factors in the selection and use of mobile app-based devices throughout the occupational therapy process based on available evidence. Considerations for mobile device implementation during the occupational therapy process is addressed, including evaluating outcomes needs, matching device with the client, and identifying support needs of the client.

  12. Laser device

    Science.gov (United States)

    Scott, Jill R.; Tremblay, Paul L.

    2007-07-10

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  13. Common Ambient Assisted Living Home Platform for Seamless Care

    DEFF Research Database (Denmark)

    Wagner, Stefan Rahr; Stenner, Rene; Memon, Mukhtiar;

    The CareStore project is investigating the feasibility of creating an open and flexible infrastructure for facilitating seamless deployment of assisted living devices and applications on heterogeneous platforms. The Common Ambient Assisted Living Home Platform (CAALHP) is intended to be the main...

  14. Interaction design concepts for a mobile personal assistant

    NARCIS (Netherlands)

    Nagata, S.F.; Oostendorp, H. van; Neerincx, M.A.

    2004-01-01

    The Personal Assistant for onLine Services (PALS) project aims to develop an intelligent interface that facilitates efficient user interaction through personalization and context awareness with commerce web sites on a handheld device. The types of assistance services and interaction support represen

  15. 28 CFR 3.2 - Assistant Attorney General, Criminal Division.

    Science.gov (United States)

    2010-07-01

    .... (See also 28 CFR 0.55(i).) (28 U.S.C. 509 and 510) ... Division. 3.2 Section 3.2 Judicial Administration DEPARTMENT OF JUSTICE GAMBLING DEVICES § 3.2 Assistant Attorney General, Criminal Division. The Assistant Attorney General, Criminal Division, is authorized...

  16. 便携式负压引流装置促进创面愈合的实验研究%Portable vacuum assisted closure device promotes wound hea1ing

    Institute of Scientific and Technical Information of China (English)

    宋鹏; 薛云; 葛宝丰; 陈克明; 赵东华; 韩桂秋; 王勇

    2011-01-01

    To assess the drainage of blast wounds with a portable vacuum drainage device made in China(patent number: ZL200920168550.9) in order to provide a new idea for the development of equipments used in early treatment of war wounds. Methods Sixteen blast wounds induced by explosion of a specific type of electric detonations fixed on hips of 8 healthy adult Landrace pigs were divided into experimental group and control group. According to the characteristics of treatment on the battlefield, blast wounds in experimental group were treated with VAC under the pressure of -(50 ± 5)kPa after debridement and sterilization and those in control group were treated with routine redressing. Bacteriology, hydroxyproline and pathology(HE staining) were detected at each time point. Results The bacteria loads were (7.82 ± 055) x 103 CFU /g in experimental group and increased to (1.07 ± 0.14) x 106 CFU/g in control group(P<0.05), while the hydroxyproline was (82.13 ± 2.14)mg/g in experimental group and (39.76 ± 4.37)mg/g in control group(P<0.05) 3 days after treatment. Pathological examination showed that the wounds were cleaner and the necrotic tissue was less in experimental group with a wealth of new granulation tissue and blood vessels than those in control group 3 days after treatment. Conclusion Portable vacuum drainage device can effectively drain blast wounds and is easy to operate. Further clinical validation is needed.%目的 评估有发明专利的自制便携式负压引流装置(专利号:ZL200920168550.9)对爆炸创面的引流效果,为开发战伤早期救治装备提供新思路.方法 选取健康长白猪8头,体质量50kg左右,用电雷管紧贴双侧臀部皮肤,造成16个损伤程度相当的爆炸创面,左右创面配对分成实验组和对照组.在室外暴露3h后进行清创,实验组用封闭负压引流处理,负压值维持在-(50±5)kPa;对照组用无菌干纱布覆盖.分别于清创前、清创后和3d后进行大体观察、细菌学计数

  17. App-assisted external ventricular drain insertion.

    Science.gov (United States)

    Eftekhar, Behzad

    2016-09-01

    The freehand technique for insertion of an external ventricular drain (EVD) is based on fixed anatomical landmarks and does not take individual variations into consideration. A patient-tailored approach based on augmented-reality techniques using devices such as smartphones can address this shortcoming. The Sina neurosurgical assist (Sina) is an Android mobile device application (app) that was designed and developed to be used as a simple intraoperative neurosurgical planning aid. It overlaps the patient's images from previously performed CT or MRI studies on the image seen through the device camera. The device is held by an assistant who aligns the images and provides information about the relative position of the target and EVD to the surgeon who is performing EVD insertion. This app can be used to provide guidance and continuous monitoring during EVD placement. The author describes the technique of Sina-assisted EVD insertion into the frontal horn of the lateral ventricle and reports on its clinical application in 5 cases as well as the results of ex vivo studies of ease of use and precision. The technique has potential for further development and use with other augmented-reality devices. PMID:26654178

  18. Nanoscale Electronic Devices

    Science.gov (United States)

    Jing, Xiaoye

    Continuous downscaling in microelectronics has pushed conventional CMOS technology to its physical limits, while Moore's Law has correctly predicted the trend for decades, each step forward is accompanied with unprecedented technological difficulties and near-exponential increase in cost. At the same time, however, demands for low-power, low-cost and high-speed devices have never diminished, instead, even more stringent requirements have been imposed on device performances. It is therefore crucial to explore alternative materials and device architectures in order to alleviate the pressure caused by downscaling. To this end, we investigated two different approaches: (1) InSb nanowire based field effect transistors (NWFETs) and (2) single walled carbon nanotube (SWCNT) -- peptide nucleic acid (PNA) --SWCNT conjugate. Two types of InSb nanowires were synthesized by template-assisted electrochemistry and chemical vapor deposition (CVD) respectively. In both cases, NWFETs were fabricated by electron beam lithography (EBL) and crystallinity was confirmed by transmission electron microscopy (TEM) and selected area diffraction (SAD) patterns. For electrochemistry nanowire, ambipolar conduction was observed with strong p-type conduction, the effect of thermal annealing on the conductivity was analyzed, a NWFET model that took into consideration the underlapped region in top-gated NWFET was proposed. Hole mobility in the channel was calculated to be 292.84 cm2V-1s -1 with a density of 1.5x1017/cm3. For CVD nanowire, the diameter was below 40nm with an average of 20nm. Vapor-liquid-solid (VLS) process was speculated to be the mechanism responsible for nanowire growth. The efficient gate control was manifested by high ION/I OFF ratio which was on the order of 106 and a small inverse subthreshold slope (chemically functionalized single walled carbon nanotubes to synthesize the conjugate and characterized its electrical properties. Negative differential resistance (NDR) was

  19. Standing Tall: The Benefits of Standing Devices

    Science.gov (United States)

    Warner, Mark P.

    2007-01-01

    In the author's opinion as a pediatric physical therapist, with the exception of a wheelchair, there is no other piece of assistive technology that is more beneficial to children and adults with special needs than a standing device. Postural symmetry during standing and walking activities is extremely important for everyone. Very few children…

  20. The comparison of the curative effect between the left univentricular pacing and the biventricular pacing in patients with chronic heart failure%单纯左室起搏与双心室起搏治疗慢性心力衰竭的疗效比较

    Institute of Scientific and Technical Information of China (English)

    王徐乐; 邱春光; 韩战营; 卢文杰; 陈晓杰; 秦石诚; 张瑞芳

    2011-01-01

    目的比较单纯左室起搏与双心室起搏治疗慢性心力衰竭(CHF)的可行性及临床效果.方法选择窦性心律、NYHA心功能分级Ⅲ~Ⅳ级、左室射血分数(LVEF)≤0.35、QRS波时限≥120 ms的CHF患者36例,成功植入心脏再同步化(CRT)起搏器后,随机分为两组,第一组先以右房左室起搏模式治疗(LV起搏模式)7天,然后以右房双室起搏模式治疗(Biv起搏模式)7天;第二组先以Biv治疗7天,然后以LV治疗7天.收集术前、术后第7天、第14天的临床资料,所有数据应用交叉设计资料方差分析及单变量一般线性模型分析.结果6 min步行距离、明尼苏达生活质量评分、体表心电图QRS波时限、左室舒张末期内径、左室射血分数、左室间隔部与侧壁基底段收缩期达峰时间差值等6种评价指标的结果相似:评价指标测量值在处理效应即LV、Biv两种起搏模式上、在顺序效应即两种起搏模式顺序上的差异均无统计学意义(P均>0.05);但在阶段效应即术后第7天、第14天两阶段上的差异有统计学意义(P<0.05).结论单纯左室起搏与双心室起搏治疗CHF的疗效相仿;对窦性心律、完全性左束支传导阻滞的CHF患者,单纯左室起搏可作为CRT的一种选择.%Objective To compare the curative effect of the left univentricular pacing with that of the biventricular pacing in patients with chronic heart failure(CHF). Methods Thirty-six patients who had left ventricular ejection fraction (LVEF) less than or equal to 0.35, a QRS duration greater than or equal to 0.12 seconds, sinus rhythm and New York Heart Association (NYHA) function Class Ⅲ or ambulatory Class Ⅳ heart failure symptoms with optimal medical therapy were divided into two groups randomly after the successful implantation of CRT/CRTD. The first group was wroking first with left univentricular pacing for 7 days, then the biventricular pacing for the next 7 days, and the second group was just the

  1. The Use of Personal Data Assistants in Early Childhood Assessment

    Science.gov (United States)

    Ledoux, Michael W.; Yoder, Noreen N.; Hanes, Barbara

    2010-01-01

    Four early childhood education teachers, two veteran and two newer teachers, were asked to pilot the use of handheld Personal Data Assistants loaded with Childchart assessment software. The participants were observed in their use of the electronic devices for monitoring student performance and interviewed regarding the use of the devices and their…

  2. Human-robot interaction strategies for walker-assisted locomotion

    CERN Document Server

    Cifuentes, Carlos A

    2016-01-01

    This book presents the development of a new multimodal human-robot interface for testing and validating control strategies applied to robotic walkers for assisting human mobility and gait rehabilitation. The aim is to achieve a closer interaction between the robotic device and the individual, empowering the rehabilitation potential of such devices in clinical applications. A new multimodal human-robot interface for testing and validating control strategies applied to robotic walkers for assisting human mobility and gait rehabilitation is presented. Trends and opportunities for future advances in the field of assistive locomotion via the development of hybrid solutions based on the combination of smart walkers and biomechatronic exoskeletons are also discussed. .

  3. Liquid crystal device and method thereof

    Science.gov (United States)

    Shiyanovskii, Sergij V; Gu, Mingxia; Lavrentovich, Oleg D

    2012-10-23

    The invention provides a liquid crystal device and method thereof. Subsequent to applying a first electrical voltage on a liquid crystal to induce a reorientation of the liquid crystal, a second electrical voltage with proper polarity is applied on the liquid crystal to assist the relaxation of the reorientation that was induced by the first electrical voltage. The "switch-off" phase of the liquid crystal can therefore be accelerated or temporally shortened, and the device can exhibit better performance such as fast response to on/off signals. The invention can be widely used LCD, LC shutter, LC lens, spatial light modulator, telecommunication device, tunable filter, beam steering device, and electrically driven LC device, among others.

  4. Treatment of Infected Cardiac Implantable Electronic Devices.

    Science.gov (United States)

    Fakhro, Abdulla; Jalalabadi, Faryan; Brown, Rodger H; Izaddoost, Shayan A

    2016-05-01

    With their rising benefits, cardiac implantable electronic devices (CIEDs) such as pacemakers and left ventricular assist devices (LVADs) have witnessed a sharp rise in use over the past 50 years. As indications for use broaden, so too does their widespread employment with its attendant rise of CIED infections. Such large numbers of infections have inspired various algorithms mandating treatment. Early diagnosis of inciting organisms is crucial to tailoring appropriate antibiotic and or antifungal treatment. In addition, surgical debridement and explant of the device have been a longstanding modality of care. More novel therapies focus on salvage of the device by way of serial washouts and instilling drug-eluting antibiotic impregnated beads into the wound. The wound is then serially debrided until clean and closed. This technique is better suited to patients whose device cannot be removed, patients who are poor candidates for cardiac surgery, or patients who have failed conventional prior treatments. PMID:27152097

  5. Solid-state electronic devices an introduction

    CERN Document Server

    Papadopoulos, Christo

    2014-01-01

    A modern and concise treatment of the solid state electronic devices that are fundamental to electronic systems and information technology is provided in this book. The main devices that comprise semiconductor integrated circuits are covered in a clear manner accessible to the wide range of scientific and engineering disciplines that are impacted by this technology. Catering to a wider audience is becoming increasingly important as the field of electronic materials and devices becomes more interdisciplinary, with applications in biology, chemistry and electro-mechanical devices (to name a few) becoming more prevalent. Updated and state-of-the-art advancements are included along with emerging trends in electronic devices and their applications. In addition, an appendix containing the relevant physical background will be included to assist readers from different disciplines and provide a review for those more familiar with the area. Readers of this book can expect to derive a solid foundation for understanding ...

  6. Capacitor ageing in electronic devices

    Directory of Open Access Journals (Sweden)

    Richard B. N. Vital

    2015-10-01

    Full Text Available The moment when an electronic component doesn’t work like requirements, previously established is a task that need to be considered since began of a system design. However, the use of different technologies, operating under several environmental conditions, makes a component choice a complex step in system design. This paper analyzes the effects that ageing phenomenon of capacitors may introduce in electronic devices operation. For this reason, reliability concepts, processes and mechanism of degradation are presented. Additionally, some mathematical models are presented to assist maintenance activities or component replacement. The presented approach compares the operability of intact and aged components.

  7. Laser assisted hair-removal.

    Science.gov (United States)

    Choudhary, S; Elsaie, M L; Nouri, K

    2009-10-01

    A number of lasers and light devices are now available for the treatment of unwanted hair. The goal of laser hair removal is to damage stem cells in the bulge of the hair follicle by targeting melanin, the endogenous chromophore for laser and light devices utilized to remove hair. The competing chromophores in the skin and hair, oxyhemoglobin and water, have a decreased absorption between 690 nm and 1000 nm, thus making this an ideal range for laser and light sources. Laser hair removal is achieved through follicular unit destruction based on selective photothermolysis. The principle of selective photothermolysis predicts that the thermal injury will be restricted to a given target if there is sufficient selective absorption of light and the pulse duration is shorter than the thermal relaxation time of the target. This review will focus on the mechanisms of laser assisted hair removal and provide an update on the newer technologies emerging in the field of lasers assisted hair removal. PMID:19834437

  8. ForeignAssistance.gov

    Data.gov (United States)

    US Agency for International Development — ForeignAssistance.gov provides a view of U.S. Government foreign assistance funds across agencies and enables users to explore, analyze, and review aid investments...

  9. Assisted Living Community Profile

    Science.gov (United States)

    ... for the Seniors Housing & Care Industry, reflects NCAL's philosophy of assisted living. 2 Data also from the ... Assisted Living Studies Clinical Practice Guidelines Health Information Technology In-Service Training Tools Periodicals State Regulatory Review ...

  10. Assisted Reproductive Technology (ART)

    Science.gov (United States)

    ... Information Clinical Trials Resources and Publications Assisted Reproductive Technology (ART) Skip sharing on social media links Share ... American Society for Reproductive Medicine. (2012). Assisted reproductive technologies: A guide for patients . Retrieved June 11, 2012, ...

  11. Exotendons for assistance of human locomotion

    Directory of Open Access Journals (Sweden)

    van den Bogert Antonie J

    2003-10-01

    Full Text Available Abstract Background Powered robotic exoskeletons for assistance of human locomotion are currently under development for military and medical applications. The energy requirements for such devices are excessive, and this has become a major obstacle for practical applications. Legged locomotion in many animals, however, is very energy efficient. We propose that poly-articular elastic mechanisms are a major contributor to the economy of locomotion in such specialized animals. Consequently, it should be possible to design unpowered assistive devices that make effective use of similar mechanisms. Methods A passive assistive technology is presented, based on long elastic cords attached to an exoskeleton and guided by pulleys placed at the joints. A general optimization procedure is described for finding the best geometrical arrangement of such "exotendons" for assisting a specific movement. Optimality is defined either as minimal residual joint moment or as minimal residual joint power. Four specific exotendon systems with increasing complexity are considered. Representative human gait data were used to optimize each of these four systems to achieve maximal assistance for normal walking. Results The most complex exotendon system, with twelve pulleys per limb, was able to reduce the joint moments required for normal walking by 71% and joint power by 74%. A simpler system, with only three pulleys per limb, could reduce joint moments by 46% and joint power by 47%. Conclusion It is concluded that unpowered passive elastic devices can substantially reduce the muscle forces and the metabolic energy needed for walking, without requiring a change in movement. When optimally designed, such devices may allow independent locomotion in patients with large deficits in muscle function.

  12. Evaluation of the optimal driving mode during left ventricular assist with pulsatile catheter pump in calves

    NARCIS (Netherlands)

    Mihaylov, D; Verkerke, GJ; Blanksma, PK; Elstrodt, J; de Jong, ED; Rakhorst, G

    1999-01-01

    The pulsatile catheter (PUCA) pump, a left ventricular assist device, was tested during acute experiments in calves using asynchronous and EGG-synchronous assist modes. The aim of the study is to compare ECG-synchronous and asynchronous assist and to find the optimal driving mode for the PUCA pump w

  13. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproductive microscopes and microscope... Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a) Identification. Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which...

  14. Development of Power Assisting Suit

    Science.gov (United States)

    Yamamoto, Keijiro; Ishii, Mineo; Hyodo, Kazuhito; Yoshimitsu, Toshihiro; Matsuo, Takashi

    In order to realize a wearable power assisting suit for assisting a nurse to carry a patient in her arms, the power supply and control systems of the suit have to be miniaturized, and it has to be wireless and pipeline-less. The new wearable suit consists of shoulders, arms, back, waist and legs units to be fitted on the nurse's body. The arms, waist and legs have new pneumatic rotary actuators driven directly by micro air pumps supplied by portable Ni-Cd batteries. The muscle forces are sensed by a new muscle hardness sensor utilizing a sensing tip mounted on a force sensing film device. An embedded microcomputer is used for the calculations of control signals. The new wearable suit was applied practically to a human body and a series of movement experiments that weights in the arms were held and taken up and down was performed. Each unit of the suit could transmit assisting torque directly to each joint verifying its practicability.

  15. Infrared criminalistic devices

    Science.gov (United States)

    Gibin, Igor S.; Savkov, E. V.; Popov, Pavel G.

    1996-12-01

    We are presenting the devices of near-IR spectral range in this report. The devices may be used in criminalistics, in bank business, in restoration works, etc. the action principle of these devices is describing briefly.

  16. Intrauterine devices (IUD)

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007635.htm Intrauterine devices (IUD) To use the sharing features on this page, please enable JavaScript. An intrauterine device (IUD) is a small plastic T-shaped device used ...

  17. Medical Device Safety

    Science.gov (United States)

    A medical device is any product used to diagnose, cure, or treat a condition, or to prevent disease. They ... may need one in a hospital. To use medical devices safely Know how your device works. Keep ...

  18. Application and research advancement on the microwave-assisted extraction

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; ZHENG Xianzhe

    2007-01-01

    This paper summarized application and research advancement of the microwave-assisted extraction in the agriculture,food industry, environmental analytical chemistry, traditional Chinese medicine industry, and so on. The microwave-assisted extraction was manifested to be a simple device, wide area of application, high extraction efficiency, good reproducibility and low consumption of agent and time as well as low environmental pollution. At present, industrialization question of the microwave-assisted extraction technology has been attached importance, which will impel the microwave-assisted extraction technology to more development in the future.

  19. Left ventricular assist for pediatric patients with dilated cardiomyopathy using the Medos VAD cannula and a centrifugal pump.

    Science.gov (United States)

    Huang, Shu-Chien; Chi, Nai-Hsin; Chen, Chun-An; Chen, Yih-Sharng; Chou, Nai-Kuan; Ko, Wen-Je; Wang, Shoei-Shen

    2009-11-01

    Ventricular assist devices for small pediatric patients are expensive and commercially unavailable in Taiwan. We used the Medos ventricular assist device cannula (Medos, Aachen, Germany) and a centrifugal pump to support pediatric patients with dilated cardiomyopathy and decompensated heart failure. From January 2007 to December 2008, three pediatric patients with dilated cardiomyopathy were supported using a centrifugal pump as the left ventricular assist device. The Medos arterial cannula was sutured to the ascending aorta, and the Apex cannula was fixed into the left ventricular apex. When the patient was weaned off of cardiopulmonary bypass, the left ventricular assist device pump was started. The pump flow was gradually titrated according to the filling status of the left ventricle. All the left ventricular assist devices were successfully implanted and functioned well. Two patients on extracorporeal membrane oxygenation had severe lung edema before left ventricular assist device implantation. Both patients required extracorporeal membrane oxygenation for the postoperative period until the pulmonary edema was resolved. Among the three patients, two successfully bridged to heart transplantation after support for 6 and 11 days, respectively. The first patient (10 kg) expired due to systemic emboli 30 days after left ventricular assist device support. In summary, these results suggest that the Medos ventricular assist device cannula and a centrifugal pump is an option for temporary left ventricular assist device support in patients with intractable heart failure and as a bridge to heart transplantation.

  20. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  1. From Computer Assisted Language Learning (CALL) to Mobile Assisted Language Use (MALU)

    Science.gov (United States)

    Jarvis, Huw; Achilleos, Marianna

    2013-01-01

    This article begins by critiquing the long-established acronym CALL (Computer Assisted Language Learning). We then go on to report on a small-scale study which examines how student non-native speakers of English use a range of digital devices beyond the classroom in both their first (L1) and second (L2) languages. We look also at the extent to…

  2. Ultraefficient Themoelectric Devices Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermoelectric (TE) devices already found a wide range of commercial, military and aerospace applications. However, at present commercially available TE devices...

  3. Assistive technology and passengers with special assistance needs in air transport: contributions to cabin design

    Directory of Open Access Journals (Sweden)

    Carina Campese

    2016-06-01

    Full Text Available Abstract There has been significant growth in air transport worldwide, as well as in Brazil. However, studies have emphasized that disabled, obese, and elderly passengers face difficulties when using this means of transport. Among these difficulties, issues related to passengers’ own assistive devices, including damage, loss, or the impossibility of using during the entire flight, stand out. Therefore, the present study aims to understand the trends in assistive technology focusing on cabin design. This research is based upon literature review, interviews with manufacturers and research centers, visits to specialized trade fairs, and patent search. The results revealed a great diversity of assistive products, its trends, and an increase in their use, which affect aircraft cabin design, especially in terms of space, access, and stowage of these devices.

  4. Avaliação de um dispositivo portátil para biópsia vácuo-assistida de microcalcificações mamárias Evaluation of a portable device for vacuum-assisted biopsy of breast microcalcifications

    Directory of Open Access Journals (Sweden)

    Hélio Sebastião Amâncio de Camargo Júnior

    2010-04-01

    Full Text Available OBJETIVO: A biópsia vácuo-assistida é a forma percutânea de biópsia de microcalcificações que obtém a menor taxa de subestimação, porém, seu custo é alto, havendo interesse em se conseguir formas mais baratas de biópsia vácuo-assistida. O objetivo deste trabalho foi testar um dispositivo portátil de biópsia vácuo-assistida que apresenta custo menor. MATERIAIS E MÉTODOS: Foram biopsiadas 35 pacientes que apresentavam agrupamentos de microcalcificações BI-RADS® 4 ou 5. Foram testados a representatividade dos fragmentos colhidos, as dificuldades na reintrodução da cânula e o número de ciclos de colheita. RESULTADOS: Houve obtenção de calcificações representativas em todas as pacientes. Não houve discordância anatomorradiológica, dificuldade na reintrodução da cânula ou complicações graves. CONCLUSÃO: Os dados permitem concluir que o sistema apresenta boa eficácia na obtenção das amostras e com relação de custo-benefício favorável em relação a outros sistemas para a biópsia de microcalcificações, achados em concordância com outras publicações da literatura.OBJECTIVE: Vacuum-assisted biopsy is the percutaneous technique of breast biopsy with the lowest underestimation rate. However, the cost of such procedure is high and currently there is a considerable interest in developing less expensive techniques. The present study was aimed at testing a less expensive device for vacuum-assisted biopsy of breast microcalcifications. MATERIALS AND METHODS: Thirty-five patients with clustered microcalcifications classified as BI-RADS® 4 or 5 were submitted to biopsy. Collected specimen appropriateness, difficulties in the reinsertion of the cannula and number of biopsy passes were evaluated. RESULTS: Successful specimens collection was achieved in all of the patients. Histo-radiological disagreement, difficulties in the cannula reinsertion or severe complications were not observed. CONCLUSION: The authors

  5. EFFECT OF APPLIED VOLTAGE ON BIO-HYDROGEN PRODUCTION FROM ACETIC ACID USING A SINGLE-CHAMBER ELECTROLYTICALLY ASSISTED BIO-HYDROGEN PRODUCTION DEVICE%电解电压对乙酸单池电解协助发酵产氢的影响

    Institute of Scientific and Technical Information of China (English)

    李建昌; 孙可伟; 杨斌; 王文根; 尹芳; 张无敌

    2011-01-01

    A single-cell electrolytically assisted device for bio-hydrogen production was used to investigate the effect of applied voltage on electrochemically assisted bio-hydrogen production from acetic acid by using anaerobic activated sludge as inoculum and sodium acetate as substrate, at the temperature of 35°C and anaerobic condition. The results showed that applied voltage was a main control parameter. When the value of applied voltage was about 250mV, current began to occur, and then bio-gas was produced. Until applied voltage went up from 0. 8V to 1.0V, hydrogen content changed from 15% to 30%. Hence, it was suitable for bio-hydrogen production from acetic acid at an applied voltage of 0. 8V to 1. 0V. However, when investigation of hydrogen potential was futher carried out under a constant applied voltage of 1.0V, the hydrogen potential was only 0.039mol H2/mol acetate due to the forming of methane.%采用单池电解协助发酵产氢装置,以厌氧活性污泥为接种物,以产酸发酵末端产物乙酸为底物,在35℃下,研究电解电压对乙酸的微生物电化学辅助产氢的影响.结果表明:电解电压是电解协助发酵制氢的主要控制参数,当电解电压约为250mV时,电解电流开始出现,随后有气体产生,当电解电压从0.8V升至1.0V时,氢气含量从15%升至30%,因此乙酸单池电解协助产氢的适宜电压为0.8~1.0V;在恒定电解电压1.0V下,由于有甲烷的形成,乙酸的氢转化率仅为0.039mol H2/mol乙酸.

  6. Erythropoietic protoporphyria and pretransplantation treatment with nonbiological liver assist devices

    DEFF Research Database (Denmark)

    Eefsen, Martin; Rasmussen, Allan; Wulf, Hans Christian;

    2007-01-01

    of patients liver failure is a significant complication and liver transplantation is the only treatment option. Damage to both abdominal skin and organs occurs when exposed to operating light; however, this problem can be ameliorated by the use of filters that block the transmission of light with wavelength...... below 470 nm. A more unusual but very serious complication postoperatively is severe motor neuropathy, with few or no known acute available precautions. An effective treatment option is needed to manage EPP crises and to prevent complications after liver transplantation. We successfully treated...... made a reduction in RBC-PPIX concentration of 0.8%. Following treatment sessions with MARS and Prometheus, the clinical condition was markedly improved and orthotopic liver transplantation was performed without further complications. In conclusion, extracorporeal therapy with MARS or Prometheus seems...

  7. PulseCath (R) as a right ventricular assist device

    NARCIS (Netherlands)

    Arrigoni, Sara Camilla; Kuijpers, Michiel; Mecozzi, Gianclaudio; Mariani, Massimo Alessandro

    2011-01-01

    The PulseCath (R) is a pulsatile pump that offers a circulatory support up to 3 l/min. The PulseCath (R) is indicated for patients who require a higher degree of support than that offered by the intra-aortic balloon pump. We describe the first two cases of the use of the PulseCath (R) as a temporary

  8. 76 FR 61655 - Definition of Part 15 Auditory Assistance Device

    Science.gov (United States)

    2011-10-05

    ... in Rulemaking Proceedings, 63 FR 24121 (1998). Electronic Filers: Comments may be filed..., a provider of simultaneous interpretation equipment and services, for marketing, as a component of... wide channels, ample spectrum is available for multiple applications. Thus, the Commission...

  9. Self-assembled nanostructured resistive switching memory devices fabricated by templated bottom-up growth

    OpenAIRE

    Ji-Min Song; Jang-Sik Lee

    2016-01-01

    Metal-oxide-based resistive switching memory device has been studied intensively due to its potential to satisfy the requirements of next-generation memory devices. Active research has been done on the materials and device structures of resistive switching memory devices that meet the requirements of high density, fast switching speed, and reliable data storage. In this study, resistive switching memory devices were fabricated with nano-template-assisted bottom up growth. The electrochemical ...

  10. Implantable CMOS Biomedical Devices

    Directory of Open Access Journals (Sweden)

    Toshihiko Noda

    2009-11-01

    Full Text Available The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented.

  11. Hip supporting device

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a device for limiting movements in one or more anatomical joints, such as a device for limiting movement in the human hip joint after hip replacement surgery. This is provided by a device for limiting movement in the human hip joint, said device comprising: at least...

  12. LUCAS - Lund University Cardiopulmonary Assist System

    OpenAIRE

    Liao, Qiuming

    2011-01-01

    Lund University Cardiopulmonary Assist System (LUCAS) is a mechanical device providing automatic 5 cm deep chest compressions and active decompressions back to normal anatomical position with a frequency of 100 per minute, and a duty cycle of 50%, i.e., LUCAS is constructed to give chest compressions according to the latest international guidelines in cardiopulmonary resuscitation (CPR). The aim of the thesis was to study cardiac arrest using different porcine models of ventricular fi...

  13. Assistance Focus: Africa (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2014-12-01

    The Clean Energy Solutions Center Ask an Expert service connects governments seeking policy information and advice with one of more than 30 global policy experts who can provide reliable and unbiased quick-response advice and information. The service is available at no cost to government agency representatives from any country and the technical institutes assisting them. This publication presents summaries of assistance provided to African governments, including the benefits of that assistance.

  14. Solar Energy: Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices (Small 19/2016).

    Science.gov (United States)

    Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

    2016-05-01

    Nanoengineered materials and structures can harvest light efficiently for photovoltaic applications. Device structure design optimization and material property improvement are equally important for high performance. On page 2536, X. Mo, Z. Fan, and co-workers summarize the design guidelines of solar energy harvesting devices to assist with a better understanding of device physics.

  15. Solar Energy: Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices (Small 19/2016).

    Science.gov (United States)

    Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

    2016-05-01

    Nanoengineered materials and structures can harvest light efficiently for photovoltaic applications. Device structure design optimization and material property improvement are equally important for high performance. On page 2536, X. Mo, Z. Fan, and co-workers summarize the design guidelines of solar energy harvesting devices to assist with a better understanding of device physics. PMID:27167321

  16. Assisted suicide and euthanasia.

    Science.gov (United States)

    van der Heide, Agnes

    2013-01-01

    Several countries have adopted laws that regulate physician assistance in dying. Such assistance may consist of providing a patient with a prescription of lethal medication that is self-administered by the patient, which is usually referred to as (physician) assistance in suicide, or of administering lethal medication to a patient, which is referred to as euthanasia. The main aim of regulating physician assistance in dying is to bring these practices into the open and to provide physicians with legal certainty. A key condition in all jurisdictions that have regulated either assistance in suicide or euthanasia is that physicians are only allowed to engage in these acts upon the explicit and voluntary request of the patient. All systems that allow physician assistance in dying have also in some way included the notion that physician assistance in dying is only accepted when it is the only means to address severe suffering from an incurable medical condition. Arguments against the legal regulation of physician assistance in dying include principled arguments, such as the wrongness of hastening death, and arguments that emphasize the negative consequences of allowing physician assistance in dying, such as a devaluation of the lives of older people, or people with chronic disease or disabilities. Opinion polls show that some form of accepting and regulating euthanasia and physician assistance in suicide is increasingly supported by the general population in most western countries. Studies in countries where physician assistance in dying is regulated suggest that practices have remained rather stable in most jurisdictions and that physicians adhere to the legal criteria in the vast majority of cases.

  17. Rhetorical Devices in English Advertisements

    Institute of Scientific and Technical Information of China (English)

    陈芃

    2011-01-01

    In order to achieve persuasive and convincing effects,rhetorical devices are frequently applied in English advertisements.The paper classifies rhetorical devices into four basic categories: phonetic devices,lexical devices,syntactic devices and figures of

  18. Egress door opening assister

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Thomas L.

    2015-10-06

    A door opening spring assistance apparatus is set forth that will automatically apply a door opening assistance force using a combination of rods and coil springs. The release of the rods by the coil springs reduces the force required to set the door in motion.

  19. Medical Assisting Program Guide.

    Science.gov (United States)

    Georgia Univ., Athens. Dept. of Vocational Education.

    This guide presents the standard curriculum for technical institutes in Georgia. The curriculum addresses the minimum competencies for a medical assisting program. The program guide is designed to relate primarily to the development of those skills needed by individuals in the medical assisting field, such as medical law and ethics, typing,…

  20. Speech recovery device

    Energy Technology Data Exchange (ETDEWEB)

    Frankle, Christen M.

    2004-04-20

    There is provided an apparatus and method for assisting speech recovery in people with inability to speak due to aphasia, apraxia or another condition with similar effect. A hollow, rigid, thin-walled tube with semi-circular or semi-elliptical cut out shapes at each open end is positioned such that one end mates with the throat/voice box area of the neck of the assistor and the other end mates with the throat/voice box area of the assisted. The speaking person (assistor) makes sounds that produce standing wave vibrations at the same frequency in the vocal cords of the assisted person. Driving the assisted person's vocal cords with the assisted person being able to hear the correct tone enables the assisted person to speak by simply amplifying the vibration of membranes in their throat.