A5052233427- Mechanical Circulatory Support Devices
- Cardiac Structural Anomalies and Repair
- Hydraulic and Pneumatic Systems
- Fuel Cells and Related Materials
- Cardiac Arrest and Resuscitation
- Cavitation Phenomena in Pumps
- Electric and Hybrid Vehicle Technologies
- Cardiac pacing and defibrillation studies
- Cardiac Valve Diseases and Treatments
- Tissue Engineering and Regenerative Medicine
- Cardiac and Coronary Surgery Techniques
- Cardiovascular Function and Risk Factors
- Hemoglobin structure and function
- Cardiac Arrhythmias and Treatments
- Tribology and Lubrication Engineering
- Congenital Heart Disease Studies
- Oil and Gas Production Techniques
- Advanced Battery Technologies Research
- Magnetic Bearings and Levitation Dynamics
- Advanced battery technologies research
- Cardiac Ischemia and Reperfusion
- Transplantation: Methods and Outcomes
- Respiratory Support and Mechanisms
- Atrial Fibrillation Management and Outcomes
- Hemodynamic Monitoring and Therapy
National Cerebral and Cardiovascular Center
2016-2025
Ibaraki University
1998-2021
Hitachi (Japan)
2021
Montefiore Medical Center
2021
Cardiovascular Institute Hospital
2019
Medical University of Vienna
2013
Osaka University
2008-2013
United Cerebral Palsy
2012
Isuzu Advanced Engineering Center (Japan)
2011
Tokyo Denki University
2004
Continuous-flow left ventricular assist devices (LVADs) have greatly improved the prognosis of patients with end-stage heart failure, even if continuous flow is different from physiological in that it has less pulsatility. A novel pump controller continuous-flow LVADs been developed, which can change its rotational speed (RS) synchronization native cardiac cycle, and we speculated pulsatile mode, increases RS just systolic phase, create more pulsatility than current system constant does. The...
Abstract: We have been developing a centrifugal blood pump with magnetically suspended impeller. To improve efficiency, we investigated the performances of many kinds impeller vanes and diffusers, as well flow in gap between discs housing. found diffusers high efficiency; however, efficiency does not mean low hemolysis. It seems important to prevent generation small‐sized eddies shear stress. Hemolysis tests are carried out find optimal vane profile clearance. The index hemolysis temperature...
Abstract: Indirect measurement of the flow rate a centrifugal blood pump using driving motor current was studied. The can be expressed as function under given speed in absence energy loss resulting from uncertain mechanical contact friction. magnetically suspended (MSCP), developed by collaboration Kyoto University and NTN Inc., suitable for application this measuring method because impeller is inside housing without any contact. effect fluid viscosity on performance investigated detail, it...
To establish an efficient design process for centrifugal blood pumps, the results of computational fluid dynamics (CFD) analysis were compared to flow visualization tests and hemolysis tests, using Nikkiso pump. CFD revealed that radial gap greatly affected shear stress in outlet diffuser. The study also indicated a similar tendency. see behind impeller, we conducted comparative between models with without washout holes technique. pressure distributions impeller different both models,...
The purpose of this study was to examine the relationship between local flow conditions and hemolysis level by integrating tests, visualization, computational fluid dynamics establish practical design criteria for centrifugal blood pumps with lower levels hemolysis. Nikkiso pump used as a standard model, different values 3 geometrical parameters were tested. studied radial gap outer edge impeller vane casing wall, position outlet port, discharge angle vane. effect narrow on consistent no...
A novel control system for the EVAHEART left ventricular assist device (LVAD), known as Native Heart Load Control System (NHLCS), can change device's rotational speed (RS) in synchrony with heartbeat. The enhanced coronary flow (CoF) counter-pulse mode normal goats' hearts, so we examined CoF goats acute ischemic heart failure (HF).We studied 14 (56.1±6.9kg) HF induced by microsphere embolization. We installed and ran 4 modes [continuous support, circuit-clamp, (raise RS diastole), co-pulse...
A correlation study was conducted among quantitative flow visualization analysis, computational fluid dynamic and hemolysis tests regarding the in a centrifugal blood pump to prevent hemolysis. Particular attention paid effect of impeller/casing gap widths on volute outlet. Flow vector maps were obtained for 250% scaled‐up models with various geometries, using an argon ion laser light sheet, high speed video camera, particle tracking velocimetry. In terms results, small radial model, shear...
Abstract: The method of measuring the flow rate a centrifugal blood pump from input electric power, which will be indispensable for long‐term use such devices, was developed and applied to direct‐driven that has been by our research group. accuracy evaluated in chronic animal experiment using an adult goat. results demonstrated this carries sufficient potential instantaneous monitoring method, but errors due electromagnetic mechanical losses were not determined always precisely. detection...
Abstract: We developed an extracorporeal membrane oxygenation (ECMO) system with high antithrombogenicity and durability characteristics for prolonged continuous cardiopulmonary support. The oxygenator consists of a special hollow‐fiber‐type polyolefin gas‐exchange membrane, which has ultrathin dense layer in contact the blood, order to prevent plasma leakage during protracted use (Platinum Cube NCVC). centrifugal pump (RotaFlow) is free seals. entire blood‐contacting surface coated newly...
In the mechanism of damage to red blood cells (RBCs) caused by a centrifugal pump, prolonged effects RBC membrane exposure shear stress remain unclear. We focused on band 3 protein (B3), one major proteins in skeleton, and investigated ultrastructural alterations with loaded stress. Using flow cytometry, relative amount B3 was examined relation deformability. The results, continuous low stress, showed cell downsizing, an increase density, decrease deformability membrane. Exposure high does...
In centrifugal pumps for artificial hearts, a magnetic drive with lightly loaded journal bearing system is often used. such system, the rigidity of small and impeller usually rotates over critical speed. cases, rotordynamic fluid forces play an important role shaft vibration. present study, characteristics on were examined. The measured in cases with/without whirling motion. It was found that become destabilizing wide range positive whirl. effect leakage flow also
Bridge-to-decision (BTD) devices providing temporary mechanical circulatory support should be introduced to patients with advanced heart failure. This study evaluated the effectiveness and safety of a BTD device comprising an innovative extracorporeal continuous-flow ventricular assist (VAD) driven by novel hydrodynamically levitated centrifugal flow blood pump.
Abstract: We investigated morphological changes of the arterial systems in kidneys under prolonged continuous flow left heart bypass. Twelve goats were subjected to 2 weeks pulsatile bypass followed by 4 (group CF). After autopsy, underwent pathological evaluation. Six normal healthy used as controls. The media afferent arterioles group CF frequently thickened an increase number mature smooth muscle cells (SMCs). juxtaglomerular areas (JGA) expanded because and size SMCs and/or SMC‐like...