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Suzuki Kenji K Department of Cardiovascular Surgery, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, - - 2014
The algorithm for the physiological control provided by left ventricular assist devices (LVADs) has been controversial. In particular, little is known about the physiological control algorithm (such as for achieving physiological circadian rhythms) in continuous-flow LVADs. To investigate the existence of circadian variation, we retrospectively evaluated the LVAD flow-correlated motor ...
Rezaienia Mohammad Amin MA School of Engineering and Materials Science, Queen Mary University of London, London, - - 2014
This study investigates the novel approach of placing a ventricular assist pump in the descending aorta in series configuration with the heart and compares it with the two traditional approaches of left-ventricle-to-ascending-aorta (LV-AA) and left-ventricle-to-descending-aorta (LV-DA) placement in parallel with the heart. Experiments were conducted by using the in-house simulator ...
Sonntag Simon J SJ Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, RWTH Aachen University and University Hospital Aachen, Aachen - - - 2014
Purpose: For blood pumps with long term indication, blood stagnation can result in excessive thromboembolic risks for patients. This study numerically investigates the washout performance of the left pump chamber of a pulsatile total artificial heart (TAH) as well as the sensitivity of the rotational orientation of the inlet bileaflet ...
Yang Cheng-Zhang CZ Laboratory of Analytical Biochemistry and Bioseparation, Key State Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, - - 2014
Uneven flow in free-flow electrophoresis (FFE) with a gravity-induced fraction collector caused by air-bubbles in outlets and/or imbalance of the surface tension of collecting tubes would result in a poor separation. To solve these issues, this work describes a novel collector for FFE. The collector is composed of a self-balance ...
Teman Nicholas R NR University of Michigan, Department of Surgery, ECLS Laboratory 5153, B560 MSRB II, 1150 W. Medical Center Drive, Ann Arbor, MI 48109 University of Michigan, Department of Cardiac Surgery, Cardiovascular Center, 1500 E. Medical Center Drive, Ann Arbor, MI 48109 MC3 Inc, 3526 W. Liberty, Ann Arbor, MI - - 2014
It has been suggested that pulsatile blood flow is superior to continuous flow in cardiopulmonary bypass (CPB). However, adoption of pulsatile flow (PF) technology has been limited due to practically and complexity of creating a consistent physiologic pulse. A pediatric pulsatile rotary ventricular pump (PRVP) was designed to address this ...
Pfluecke C C University of Technology Dresden, Heart Center Dresden, University Hospital, Dresden, - - 2014
The current goal of treatment after acute ischemic stroke is the increase of cerebral blood flow (CBF) in ischemic brain tissue. Intra-aortic balloon pump (IABP) counterpulsation in the setting of cardiogenic shock is able to reduce left ventricular afterload and increase coronary blood flow. The effects of an IABP on ...
Park M M Research and Education Institute, Sírio Libanês Hospital, São Paulo, - - 2014
Transmembrane pressure drop reflects the resistance of an artificial lung system to blood transit. Decreased resistance (low transmembrane pressure drop) enhances blood flow through the oxygenator, thereby, enhancing gas exchange efficiency. This study is part of a previous one where we observed the behaviour and the modulation of blood pressure ...
Kimura Sumito S Department of Pediatric Cardiology, Oregon Health and Science University, 3181 SW Sam Jackson Park Dr, L608, Portland, OR 97239-3098 USA. - - 2014
Objectives- The aim of this study was to assess the accuracy, feasibility, and reproducibility of determining stroke volume from a novel 3-dimensional (3D) color Doppler flow quantification method for mitral valve (MV) inflow and left ventricular outflow tract (LVOT) outflow at different stroke volumes when compared with the actual flow ...
Borges Alessandra B AB Department of Restorative Dentistry, Universidade Estadual Paulista, São José dos Campos, - - 2014
This study investigated the effect of a calcium lactate prerinse on sodium fluoride protection in an in vitro erosion-remineralization model simulating two different salivary flow rates. Enamel and dentin specimens were randomly assigned to 6 groups (n = 8), according to the combination between rinse treatments - deionized water (DIW), ...
Shahraki Zahra Hashemi ZH * Lecturer at Mechanical department (Biomechanics group) of Islamic Azad University of Najafabad † Assistant Professor at Mechanical department (Biomechanics group) of Sahand University of - - 2014
Hemolysis and Thrombus formation which are critical concerns in designing a long-term implantable ventricular assist device (VAD) have impeded the widespread use of VADs. In this study, thus, the 3D fluid domain of blood flow in a small bi-chamber positive displacement VAD (25cc) with a magnetically levitated moving pusher plate ...
Chopski Steven G SG BioCirc Research Laboratory, Department of Mechanical and Nuclear Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, - - 2014
A mechanical blood pump specifically designed to increase pressure in the great veins would improve hemodynamic stability in adolescent and adult Fontan patients having dysfunctional cavopulmonary circulation. This study investigates the impact of axial-flow blood pumps on pressure, flow rate, and energy augmentation in the total cavopulmonary circulation (TCPC) using ...
Bottrell S S 1Perfusion Department, Royal Children's Hospital, Melbourne, Victoria, - - 2014
One challenge in providing extracorporeal circulation is to supply optimal flow while minimising adverse affects, such as haemolysis. To determine if the recent generation constrained vortex pumps with their inherent design improvements would lead to reduced red cell trauma, we undertook a study comparing three devices. Utilizing a simulated short-term ...
Li Zida Z Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China. - - 2014
We report a new method to display the minute fluctuations induced by syringe pumps on microfluidic flows by using a liquid-liquid system with an ultralow interfacial tension. We demonstrate that the stepper motor inside the pump is a source of fluctuations in microfluidic flows by comparing the frequencies of the ...
Liu Guangmao - - 2014
The properties of blood flow in the outflow cannula of an axial blood pump play a critical role in potential thrombus formation and vascular injury. In this study, an in vitro flow visualization technique using particle image velocimetry (PIV) was applied to investigate the flow characteristics in the outflow cannula ...
Kang Can - - 2014
Rotary blood pump (RBP) is a kind of crucial ventricular assist device (VAD) and its advantages have been evidenced and acknowledged in recent years. Among the factors that influence the operation performance and the durability of various rotary blood pumps, medium property and the flow features in pump's flow passages ...
Gaddum Nicholas R NR Division of Imaging Sciences and Biomedical Engineering, St. Thomas' Hospital, King's College London, London, - - 2013
The application of rotary left ventricular (LV) assist devices (LVADs) is expanding from bridge to transplant, to destination and bridge to recovery therapy. Conventional constant speed LVAD controllers do not regulate flow according to preload, and can cause over/underpumping, leading to harmful ventricular suction or pulmonary edema, respectively. We implemented ...
Hong Sungmin - - 2013
We developed a microfluidic flow-control system capable of dynamically generating various flow patterns on demand. The flow-control system is based on novel magnetoactive sponges embedded in microfluidic flow channels. Applying a non-uniform magnetic field compresses the magnetoactive sponge, significantly reducing porosity and hydraulic conductivity. Tuning the applied magnetic field can ...
Tuzun Egemen - - 2013
The effects of the continuous-flow output on renal and intestinal microcirculation have not been extensively studied. To address this, the Heartware HVAD pump loaded with continuous and intermittent reduced speed (IRS) modes was implanted in four sheep and then operated at low and high speeds to mimic partial and complete ...
Bakouri Mohsen A - - 2013
Clinically adequate implementation of physiological control of a rotary left ventricular assist device requires a sophisticated technique such as the recently proposed method based on the Frank-Starling mechanism. In this mechanism, the stroke volume of the heart increases in response to an increase in the volume of blood filling the ...
Cohn William E - - 2013
We evaluated the effects of steady state flow and perfusion on end-organ function in a long-term calf model. The animal received a continuous-flow total artificial heart (CFTAH) that we created from two axial-flow ventricular assist devices. Pump flow, blood pressure, and other pump parameters were monitored throughout the study, as ...
Wang Shigang - - 2013
The objective of this study was to evaluate the pump performance of the third-generation Medos diagonal pump, the Deltastream DP3, on hemodynamic profile and pulsatility in a simulated pediatric mechanical circulatory support (MCS) system. The experimental circuit consisted of a Medos Deltastream DP3 pump head and console (MEDOS Medizintechnik AG, ...
Leme Juliana - - 2013
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 ...
Koochaki Mojtaba - - 2013
Considering small thoracic space, using implantable ventricular assist device requires reduction in a pump size. Among many available blood pumps, axial blood pumps have attracted greatly because of their small size. In this article, a new miniature axial blood pump has been designed and studied which can be easily implanted ...
Banthitkhunanon P - - 2013
To determine the effect of enamel and dentine thickness on laser Doppler blood-flow (LDF) signals recorded from dental pulp. Observations were made on 18 human premolars that had been extracted from young patients during orthodontic treatment. The apical 2/3 of the root was cut off and the remaining pulp removed. ...
Lal Cerine - - 2013
ABSTRACT. Blood flow velocity and red blood cell concentration are of vital importance in assessing tissue microcirculation. Laser speckle contrast analysis is being considered as a promising tool in the qualitative assessment of flow velocity as well as scatterer concentration in different body fluids, though the quantification part still remains ...
da Silva Cibele - - 2013
The Spiral Pump (SP), a centrifugal blood pump for cardiopulmonary bypass (CPB), has been developed at the Dante Pazzanese Institute of Cardiology/Adib Jatene Foundation laboratories, with support from Sintegra Company (Pompeia, Brazil). The SP is a disposable pump with an internal rotor-a conically shaped fuse with double entrance threads. This ...
Geers A J - - 2013
Computational fluid dynamics (CFD) simulations can be employed to gain a better understanding of hemodynamics in cerebral aneurysms and improve diagnosis and treatment. However, introduction of CFD techniques into clinical practice would require faster simulation times. The aim of this study was to evaluate the use of computationally inexpensive steady ...
Repa A - - 2013
Blood transfusions are required by the majority of extremely premature infants. Packed red blood cells (PRBCs) are usually applied via simple peripheral cannulas. In situations where no peripheral venous access is achievable, 27 Gauge (G) neonatal PICC lines - that are ideally exclusively dedicated to application of parenteral nutrition - ...
Koning Nick J - - 2013
This study investigated the perioperative course of microcirculatory perfusion in off-pump compared with on-pump surgery. Additionally, the impact of changes in systemic hemodynamics, hematocrit, and body temperature was studied. Prospective, nonrandomized, observational study. Tertiary university hospital. Patients undergoing coronary artery bypass grafting with (n = 13) or without (n = ...
Jarvik Robert - - 2014
Blood-pump miniaturization has made amazing progress, reducing the pump diameter to one-tenth of the size of previous positive displacement pumps. In particular, axial-flow-pump technology allows tiny pumps running at high speeds to deliver from 2 to 10 L/min. A review of the background inventions of the Jarvik 2000 technology is ...
Lehle Karla - - 2013
Membrane oxygenator (MO) failure is a known hazard during venovenous extracorporeal membrane oxygenation (v-v ECMO) therapy. Knowledge about technical and performance details of different ECMO systems (Maquet, Rastatt, Germany; Medos, Stolberg, Germany; Sorin, Modena, Italy) licensed for adults with acute lung failure might improve their handling. This retrospective study comprises ...
Fine Nowell M - - 2013
This study sought to characterize the echocardiographic findings of patients presenting with intravascular hemolysis (IVH) due to suspected continuous-flow left ventricular assist device (LVAD) pump thrombosis. LVAD patients who develop pump thrombosis often present with IVH. Echocardiography may be able to detect device dysfunction in this setting. Continuous-flow LVAD patients ...
Lee Eun Gyung - - 2013
Pulsations generated by personal sampling pumps modulate the airflow through the sampling trains, thereby varying sampling efficiencies, and possibly invalidating collection or monitoring. The purpose of this study was to characterize pulsations generated by personal sampling pumps relative to a nominal flow rate at the inlet of different respirable cyclones. ...
Ozturk Pelin - - 2013
Pulmonary hypertension (PH) is considered as a risk factor for morbidity and mortality in patients undergoing heart transplantation. Recently, left ventricular assist device (LVAD) implantation has been increasingly used in reducing pulmonary artery pressure (PAP) in patients with PH unresponsive to medical therapy. Herein, we aimed to compare the efficacy ...
Yeom Eunseop - - 2013
Pulsatile blood flows are easily found in the vessels of living organisms. Under pulsatile flow conditions, red blood cells (RBCs) are aggregated and dispersed repetitively. The RBC aggregation phenomenon is an influential factor in hemorheological and hemodynamic properties. This study aims to investigate the relationship between velocity profile and RBC ...
Amaral Felipe - - 2013
Assuming that blood has a constant viscosity is a common practice when designing rotary blood pumps (RBPs), where shear stresses are generally higher than in the human body. This eases the design and allows numerical simulations and bench top experiments to be performed with Newtonian fluids. However, specific flow conditions ...
Stanfield J Ryan - - 2013
The Jarvik 2000 adult ventricular assist device (VAD) is a second-generation blood pump with mechanical contact bearings. The original configuration of the pump employed a pin bearing and a more recent configuration uses a cone bearing. We compare the hydrodynamic performance of the two designs under steady-state and pulsatile flow ...
Wong C I - - 2013
Understanding the nature of communication between aquifers can be challenging when using traditional physical and geochemical groundwater sampling approaches. This study uses two multiport wells completed within Edwards and Trinity aquifers in central Texas to determine the degree of groundwater inter-flow between adjacent aquifers. Potentiometric surfaces, hydraulic conductivities, and groundwater ...
Peng Zhi-Yong - - 2013
Unlike pharmacologic interventions in sepsis, extracorporeal blood purification, which is widely used in septic patients, is not typically studied in experimental rodents. Most of the previous studies have performed extracorporeal blood purification in larger animals and typically use arteriovenous (AV) vascular access. We developed a venovenous (VV) purification model in ...
Pilar David H F - - 2013
Most professional wind visualizations show wind speed and direction using a glyph called a wind barb in a grid pattern. Research into flow visualization has suggested that streamlines better represent flow patterns but these methods lack a key property-unlike the wind barb, they do not accurately convey the wind speed. ...
Pothérat A - - 2013
The conditions in which meridional recirculations appear in swirling flows above a fixed wall are analysed. In the classical Bodewädt problem, where the swirl tends towards an asymptotic value away from the wall, the well-known "tea-cup effect" drives a flow away from the plate at the centre of the vortex. ...
Karmonik Christof - - 2013
This study aims to investigate differences in hemodynamic conditions in the thoracic aorta for pulsatile and continuous-flow left ventricular assist devices (LVADs) using computational fluid dynamics (CFD). Patient-specific models were reconstructed from three patients with continuous-flow LVAD (HeartMate II, Thoratec Corporation) and three patients with biventricular assist devices (Excor, Berlin ...
Dhami Ranjodh - - 2013
Cardiopulmonary bypass (CPB) is used for a variety of procedures in pediatric patients. Flow settings of the CPB pump have dramatic effects on patient outcome, and gaseous microemboli delivery within the CPB circuit has been linked to neurological complications. To ensure the ongoing improvement of pediatric CPB, consistent evaluation and ...
Krawiec Conrad - - 2013
The Medos Deltastream DP3 system is made up of a novel diagonal pump and hollow-membrane oxygenator that provides nonpulsatile and pulsatile flows for extracorporeal life support (ECLS). The objectives of this study are to (i) evaluate the efficacy of the hemodynamic energy provided by Medos Deltastream DP3 system in nonpulsatile ...
Pennings Kim A M A - - 2013
The use of long-term mechanical circulatory support (MCS) for heart failure by means of implanted continuous-flow left ventricular assist devices (cf-LVADs) will increase, either to enable recovery or to provide a destination therapy. The effectiveness and user-friendliness of MCS will depend on the development of near-physiologic control strategies for which ...
Soucy Kevin G - - 2013
Ventricular assist devices (VADs) have been successfully used as a bridge to heart transplant and destination therapy (DT) for congestive heart failure (HF) patients. Recently, continuous flow VAD (CVAD) has emerged as an attractive clinical option for long-term mechanical support of HF patients, with bridge-to-transplant outcomes comparable with pulsatile flow ...
Kosaka Ryo - - 2013
In order to monitor the condition of a patient using a left ventricular assist system (LVAS), blood flow should be measured. However, the reliable determination of blood-flow rate has not been established. The purpose of the present study is to develop a noninvasive blood-flow meter using a curved cannula with ...
Bakouri Mohsen A - - 2013
In general, patient variability and diverse environmental operation makes physiological control of a left ventricular assist device (LVAD) a complex and complicated problem. In this work, we implement a Starling-like controller which adjusts mean pump flow using pump flow pulsatility as the feedback parameter. The linear relationship between mean pump ...
Ishii Kohei - - 2013
The helical flow pump (HFP) is newly developed blood pomp for total artificial heart (TAH). HFP can work with lower rotational speed than axial and centrifugal blood pump. It can be seen reasonable feature to generate pulsatile flow because high response performance can be realized. In this article, pulsatility of ...
Tanaka Akira - - 2013
Pump performance is very important property in rotary blood pumps. Suitable pump performance often creates suitable blood flow regulation in long-term circulatory support. However, it is difficult to develop the blood pump with specific pump performance. In addition, optimal pump performance is still unknown. In this study, we have proposed ...
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