Flow Rate and Pressure Head Estimation in a Centrifugal Blood Pump

2002 ◽  
Vol 26 (11) ◽  
pp. 985-990 ◽  
Author(s):  
Akio Funakubo ◽  
Shahriar Ahmed ◽  
Ichiro Sakuma ◽  
Yasuhiro Fukui
Keyword(s):  
Flow Rate ◽  
Pressure Head ◽  
Blood Pump ◽  
Centrifugal Blood Pump

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.

Design and Numerical Evaluation of an Axial Partial-assist Blood Pump for Chinese and other Heart Failure Patients

2017 ◽  
Vol 40 (9) ◽  
pp. 489-497 ◽  
Author(s):  
Guang-Mao Liu ◽  
Dong-Hai Jin ◽  
Jian-Ye Zhou ◽  
Xi-Hang Jiang ◽  
Han-Song Sun ◽  
...  
Keyword(s):  
Heart Failure ◽  
Shear Stress ◽  
Flow Rate ◽  
Tangential Velocity ◽  
Pressure Head ◽  
Left Ventricular ◽  
Blood Pump ◽  
Partial Support ◽  
Heart Failure Patients ◽  
Cantilever Structure

A fully implantable axial left ventricular assist device LAP31 was developed for Chinese or other heart failure patients who need partial support. Based on the 5-Lpm total cardiac blood output of Chinese without heart failure disease, the design point of LAP31 was set to a flow rate of 3 Lpm with 100-mmHg pressure head. To achieve the required pressure head and good hemolytic performance, a structure that includes a spindly rotor hub and a diffuser with splitter and cantilevered main blades was developed. Computational fluid dynamics (CFD) was used to analyze the hydraulic and hemodynamic performance of LAP31. Then in vitro hydraulics experiments were conducted. The numerical simulation results show that LAP31 could generate a 1 to 8 Lpm flow rate with a 60.9 to 182.7 mmHg pressure head when the pump was rotating between 9,000 and 12,000 rpm. The average scalar shear stress of the blood pump was 21.7 Pa, and the average exposure time was 71.0 milliseconds. The mean hemolysis index of LAP31 obtained using Heuser's hemolysis model and Giersiepen's model was 0.220% and 3.89 × 105% respectively. After adding the splitter blades, the flow separation at the suction surface of the diffuser was reduced. The cantilever structure reduced the tangential velocity from 6.1 to 4.7–1.4 m/s within the blade gap by changing the blade gap from shroud to hub. Subsequently, the blood damage caused by shear stress was reduced. In conclusion, the hydraulic and hemolytic characteristics of the LAP31 are acceptable for partial support.

Use of Motor Current in Flow Rate Measurement for the Magnetically Suspended Centrifugal Blood Pump

2008 ◽  
Vol 21 (5) ◽  
pp. 396-401 ◽  
Author(s):  
Tomonori Tsukiya ◽  
Teruaki Akamatsu ◽  
Kazunobu Nishimura ◽  
Tomoyuki Yamada
Keyword(s):  
Flow Rate ◽  
Blood Pump ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Centrifugal Blood Pump ◽  
Motor Current

Hydraulic Analysis and Optimization in Impeller of Magnetically Levitated Centrifugal Blood Pump

2011 ◽  
Vol 121-126 ◽  
pp. 1204-1208 ◽  
Author(s):  
Hui Min Zhang ◽  
Qi Zhu
Keyword(s):  
Fluid Dynamic ◽  
Pressure Head ◽  
Blood Pump ◽  
Hydraulic Analysis ◽  
Optimization Analysis ◽  
Centrifugal Blood Pump ◽  
Optimization Of Parameters ◽  
Fluid Field ◽  
Ansys Cfx ◽  
Magnetically Levitated

This article, on the basis of the magnetically levitated pumps developed by Ibaraki University, talks about fluid dynamic analysis of pump and optimization of parameters of the impellers. The pump uses blood as medium, with a flow rate Q of 5L/min, a pressure head H of 100mmHg. By using software of ANSYS CFX, the article analyzes the effect of shape, angle, height, length and thickness of the impeller on performance chart and fluid field distribution inside the pump. To fulfill the human requirements in blood pump, an optimization analysis is conducted to improve the uniformity of fluid field, reduce power and efficiency of the pump. As result, meeting the flow and pressure head condition, single curvature impeller is found to have lower speed, better efficiency and more uniform flow field, this helps to prevent the generation of thrombus and hemolytic.

Effects of gravity on flow rate estimations of a centrifugal blood pump using the eccentric position of a levitated impeller

2020 ◽  
Vol 43 (12) ◽  
pp. 774-781
Author(s):  
Shuya Shida ◽  
Toru Masuzawa ◽  
Masahiro Osa
Keyword(s):  
Flow Rate ◽  
Ventricular Assist Devices ◽  
Blood Pump ◽  
Accurate Estimation ◽  
Ventricular Assist ◽  
Centrifugal Blood Pump ◽  
Assist Devices ◽  
Flow Estimation ◽  
Magnetically Levitated ◽  
Gravity Direction

Implantable ventricular assist devices are a type of mechanical circulatory support for assisting the pumping of the heart. Accurate estimation of the flow rate through such devices is critical to ensure effective performance. A novel method for estimating the flow rate using the passively stabilized position of a magnetically levitated impeller was developed by our group. However, the performance of the method is affected by the gravity vector, which depends on the patient’s posture. In this study, the effects of gravity on the flow estimation method are analyzed, and a compensation method is proposed. The magnetically levitated impeller is axially suspended and radially restricted by passive stability in a centrifugal blood pump developed by our group. The gravity effects were evaluated by analyzing the relationships between the radial position of the magnetically levitated impeller and the flow rate with respect to the gravity direction. Accurate estimation of the flow rate could not be achieved when the direction of gravity with respect to impeller was unknown. A mean absolute error of up to 4.89 L/min was obtained for flow rate measurement range of 0–5 L/min. However, analysis of the equilibrium of forces on the passively stabilized impeller indicated that the effects of gravity on the flow estimation could be compensated by performing additional measurements of the gravity direction with respect to impeller. The method for compensating the effects of gravity on the flow estimation should improve the performance of therapy with the implantable ventricular assist devices.

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