scholarly journals Influence of Viscosity upon Characteristics of Magnetically Suspended Centrifugal Blood Pump and Indirect Measurement of Pressure and Flow Rate.

1996 ◽  
Vol 62 (602) ◽  
pp. 3629-3634
Author(s):  
Koji TERAUCHI ◽  
Tomonori TSUKIYA ◽  
Teruaki AKAMATSU
Keyword(s):  
Flow Rate ◽  
Indirect Measurement ◽  
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.

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

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

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.

scholarly journals PIV Measurements of Flow in a Centrifugal Blood Pump: Time-Varying Flow

2004 ◽  
Vol 127 (2) ◽  
pp. 254-263 ◽  
Author(s):  
Steven W. Day ◽  
James C. McDaniel
Keyword(s):  
Flow Field ◽  
Flow Rate ◽  
Cardiac Cycle ◽  
Transient Flow ◽  
Left Ventricular ◽  
Blood Pump ◽  
Time Varying ◽  
Rate Condition ◽  
Centrifugal Blood Pump ◽  
Pump Flow Rate

Measurements of the time-varying flow in a centrifugal blood pump operating as a left ventricular assist device (LVAD) are presented. This includes changes in both the pump flow rate as a function of the left ventricle contraction and the interaction of the rotating impeller and fixed exit volute. When operating with a pulsing ventricle, the flow rate through the LVAD varies from 0-11L∕min during each cycle of the heartbeat. Phase-averaged measurements of mean velocity and some turbulence statistics within several regions of the pump, including the inlet, blade passage, exit volute, and diffuser, are reported at 20 phases of the cardiac cycle. The transient flow fields are compared to the constant flow rate condition that was reported previously in order to investigate the transient effects within the pump. It is shown that the quasi-steady assumption is a fair treatment of the time varying flow field in all regions of this representative pump, which greatly simplifies the comprehension and modeling of this flow field. The measurements are further interpreted to identify the effects that the transient nature of the flow field will have on blood damage. Although regions of recirculation and stagnant flow exist at some phases of the cardiac cycle, there is no location where flow is stagnant during the entire heartbeat.

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