scholarly journals Experimental and numerical investigation of different geometrical parameters in a centrifugal blood pump

2022 ◽  
Author(s):  
Seyed Ehsan Hosseini ◽  
Amir Keshmiri
Keyword(s):  
Rotational Speed ◽  
Pressure Difference ◽  
Left Ventricular ◽  
Blood Pump ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Fluid Temperature ◽  
Hydraulic Efficiency ◽  
Centrifugal Blood Pump ◽  
Overall Performance

Abstract Purpose Due to the importance of public health and economics, cardiovascular disease has become one of the most important debates and challenges for scientists. However, few studies have been done to address this challenge. The main objective of this document is to provide an optimal model to improve the performance of the left ventricular assist device and reduce costs. In this way, in the present study, the experimental and numerical procedures were developed to analyze the effects of the geometrical features and operational parameters on the performance of a centrifugal blood pump (CBP). Methods In order to achieve this aim, first, experimental tests were carried out to study the influence of the working fluid temperature and the rotational speed on the CBP. Subsequently, the performance of the CBP was assessed using computational fluid dynamics (CFD), and comparison was made against the experimental data. In addition, the influence of mounting an inducer on the overall performance of CBP was also investigated. Results Good agreement between the CFD and the data was obtained. The CFD results showed that increasing the fluid temperature and rotational speed leads to an increase in the hydraulic efficiency, pressure difference, and power. In addition, the reduction of the pressure difference and hydraulic efficiency with increasing the surface roughness was observed. While mounting an inducer on the pump did not significantly impact its overall performance, the highest value of the wall shear stress dropped moderately on the impeller and, therefore, unveiled the possibility of improving the performance of such designs.

Estimation of the radial force using a disturbance force observer for a magnetically levitated centrifugal blood pump

2009 ◽  
Vol 224 (7) ◽  
pp. 913-924 ◽  
Author(s):  
C N Pai ◽  
T Shinshi ◽  
A Shimokohbe
Keyword(s):  
Rotational Speed ◽  
Fluid Dynamic ◽  
Radial Force ◽  
Magnetic Bearing ◽  
Blood Pump ◽  
Working Fluid ◽  
Computational Fluid Dynamic Analysis ◽  
Centrifugal Blood Pump ◽  
Magnetically Levitated ◽  
Radial Thrust

Evaluation of the hydraulic forces in a magnetically levitated (maglev) centrifugal blood pump is important from the point of view of the magnetic bearing design. Direct measurement is difficult due to the absence of a rotor shaft, and computational fluid dynamic analysis demands considerable computational resource and time. To solve this problem, disturbance force observers were developed, using the radial controlled magnetic bearing of a centrifugal blood pump, to estimate the radial forces on the maglev impeller. In order to design the disturbance observer, the radial dynamic characteristics of a maglev impeller were evaluated under different working conditions. It was observed that the working fluid affects the additional mass and damping, while the rotational speed affects the damping and stiffness of the maglev system. Based on these results, disturbance force observers were designed and implemented. The designed disturbance force observers present a bandwidth of 45 Hz. In non-pulsatile conditions, the magnitude of the estimated radial thrust increases in proportion to the flowrate, and the rotational speed has little effect on the force direction. At 5 l/min against 100 mmHg, the estimated radial thrust is 0.95 N. In pulsatile conditions, this method was capable of estimating the pulsatile radial thrust with good response.

An experimental performance comparison of Newtonian and non-Newtonian fluids on a centrifugal blood pump

2022 ◽  
pp. 095441192110576
Author(s):  
Ahmet Onder ◽  
Rafet Yapici ◽  
Omer Incebay
Keyword(s):  
Flow Rate ◽  
Rotational Speed ◽  
Performance Test ◽  
Newtonian Fluids ◽  
Friction Reduction ◽  
Blood Pump ◽  
Actual Performance ◽  
Centrifugal Blood Pump ◽  
Working Fluids ◽  
Pump Performance

The use of substitute fluid with similar rheological properties instead of blood is important due to ethical concerns and high blood volume consumption in pump performance test before clinical applications. The performance of a centrifugal blood pump with hydrodynamic journal bearing is experimentally tested using Newtonian 40% aqueous glycerin solution (GS) and non-Newtonian aqueous xanthan gum solution of 600 ppm (XGS) as working fluids. Experiments are performed at four different rotational speeds which are 2700, 3000, 3300, and 3600 rpm; experiments using GS reach between 8.5% and 37.2% higher head curve than experiments using the XGS for every rotational speed. It was observed that as the rotational speed and flow rate increase, the head curve difference between GS and XGS decreases. This result can be attributed to the friction reduction effect when using XGS in experiments at high rotation speed and high flow rate. Moreover, due to different fluid viscosities, differences in hydraulic efficiency were observed for both fluids. This study reveals that the use of Newtonian fluids as working fluids is not sufficient to determine the actual performance of a blood pump, and the performance effects of non-Newtonian fluids are remarkably important in pump performance optimizations.

scholarly journals Twenty-four Hour Left Ventricular BYpass with a Centrifugal Blood Pump

1975 ◽  
Vol 181 (4) ◽  
pp. 412-417 ◽  
Author(s):  
EUGENE F. BERNSTEIN ◽  
GIACOMO A. DELARAI ◽  
KAJH. JOHANSEN ◽  
ROBERT L. SHUMAN ◽  
PETER STASZ
Keyword(s):  
Left Ventricular ◽  
Blood Pump ◽  
Centrifugal Blood Pump

A Compact Centrifugal Blood Pump for Extracorporeal Circulation: Design and Performance

1987 ◽  
Vol 109 (3) ◽  
pp. 272-278 ◽  
Author(s):  
Shinobu Tanaka ◽  
Shuzo Yamamoto ◽  
Ken-ichi Yamakoshi ◽  
Akira Kamiya
Keyword(s):  
Thrombus Formation ◽  
Animal Experiments ◽  
Left Ventricular ◽  
Blood Pump ◽  
Assisted Circulation ◽  
In Vitro Tests ◽  
Outer Diameter ◽  
Centrifugal Blood Pump ◽  
And Performance

A new compact centrifugal blood pump driven by a miniature DC servomotor has been designed for use for short-term extra corporeal and cardiac-assisted circulation. The impeller of the pump was connected directly to the motor by using a simple-gear coupling. The shaft for the impeller was sealed from blood by both a V-ring and a seal bearing. Either pulsatile or nonpusatile flow was produced by controlling the current supply to the motor. The pump characteristics and the degree of hemolysis were evaluated with regard to the configuration of the impeller with a 38-mm outer diameter in vitro tests; the impeller having the blade angles at the inlet of 20 deg and at the outlet of 50 deg was the most appropriate as a blood pump. The performance in an operation, hemolysis and thrombus formation in the pump were assessed by a left ventricular bypass experiment in dogs. It was suggested by this study that this prototype pump appears promising for use not only in animal experiments but also in clinical application.

A Pivot Bearing-Supported Centrifugal Pump for a Long-Term Assist Heart

1997 ◽  
Vol 20 (4) ◽  
pp. 222-228 ◽  
Author(s):  
T. Nakazawa ◽  
Y. Ohara ◽  
R. Benkowski ◽  
K. Makinouchi ◽  
Y. Takami ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
Centrifugal Pump ◽  
Thrombus Formation ◽  
Left Ventricular ◽  
Production Model ◽  
Blood Pump ◽  
Preliminary Evaluation ◽  
Centrifugal Blood Pump ◽  
Normal Ranges ◽  
Pivot Bearing

A pivot bearing-supported centrifugal blood pump has been developed. It is a compact, cost effective, and anti-thrombogenic pump with anatomical compatibility. A preliminary evaluation of five paracorporeal left ventricular assist studies were performed on pre-conditioned bovine (70-100 kg), without cardiopulmonary bypass and aortic cross-clamping. The inflow cannula was inserted into the left ventricle (LV) through the apex and the outflow cannula affixed with a Dacron vascular graft was anastomosed to the descending aorta. All pumps demonstrated trouble free performance over a two-week screening period. Among these five studies, three implantations were subjected for one month system validation studies. All the devices were trouble free for longer than 1 month. (35, 34, and 31 days). After achieving one month studies, all experiments were terminated. There was no evidence of device induced thrombus formation inside the pump. The plasma free hemoglobin levels were within normal ranges throughout all experiments. As a consequence of these studies, a mass production model C1E3 of this pump was fabricated as a short-term assist pump. This pump has a Normalized Index of Hemolysis of 0.0007 mg/100L and the estimated wear life of the impeller bearings is longer than 8 years. The C1E3 will meet the clinical requirements as a cardiopulmonary bypass pump. For the next step, a miniaturized pivot bearing centrifugal blood pump PI-601 has been developed for use as a permanently implantable device after design optimization. The evolution from C1E3 to the PI-601 converts this pivot bearing centrifugal pump as a totally implantable centrifugal pump. A pivot bearing centrifugal pump will become an ideal assist pump for the patients with failing heart.

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