Flow rate prediction of a percutaneous ventricular assist device using nonlinear circuit analysis

2005 ◽  
Author(s):  
S. Mushi ◽  
Yih-Choung Yu ◽  
M.A. Simaan ◽  
N.V. Zorn
Keyword(s):  
Flow Rate ◽  
Ventricular Assist Device ◽  
Circuit Analysis ◽  
Nonlinear Circuit ◽  
Assist Device ◽  
Ventricular Assist ◽  
Rate Prediction ◽  
Nonlinear Circuit Analysis

scholarly journals Computational Fluid Dynamics-Based Design Optimization for an Implantable Miniature Maglev Pediatric Ventricular Assist Device

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Jingchun Wu ◽  
James F. Antaki ◽  
Josiah Verkaik ◽  
Shaun Snyder ◽  
Michael Ricci
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Design Optimization ◽  
Flow Rate ◽  
Ventricular Assist Device ◽  
Flow Path ◽  
Flow Section ◽  
Rotor Speed ◽  
Assist Device ◽  
Ventricular Assist

Computational fluid dynamics (CFD)-based design optimization was applied to achieve the finalized design of the PediaFlow® PF4, a magnetically levitated rotodynamic pediatric ventricular assist device. It features a streamlined blood-flow path with a single annular fluid passage between the rotor and the stationary housing. The resulting impeller is composed of a first-stage mixed-flow section having four blades at the conical nose region followed by a second-stage fully axial-flow section with three blades within the annular gap region. A stator with three inwardly-directed vanes is provided at the conical tail region to recover pressure and straighten the flow. CFD predictions of head and efficiency characteristics agreed remarkably well with the validation experimental data: with overprediction of head by <7 mmHg over the entire operational range and a slight overprediction in best efficiency by ∼1%. The new optimized PF4 extended the maximum flow range of the previous PF3 device by more than 100% to over 2.3 liter per minute (LPM) for the same range of operating speeds, and doubled the maximum hydraulic efficiency to ∼27%. Evaluation of hemolysis was performed by a Lagrangian particle-tracking technique with analysis of regional contributions to the overall blood damage. The simulation revealed that hemolysis increases with an increase in both the flow rate and rotor speed but not necessarily with just an increase in flow rate at a constant rotor speed. At the flow rate of 1.0 LPM and a head of 138 mmHg, PF4 has a hemolysis index of 0.0032 compared to 0.0058 produced by PF3 at the same flow rate with a head of 48 mmHg. Numerical simulation of radial fluid forces performed by the CFD model with an eccentric rotor revealed the presence of negative fluid stiffness that was monotonically related to both flow and speed. Finally, conjugate heat transfer analysis predicted temperature rise adjacent to the motor to be inversely proportional to the length, but not exceeding ∼2 °C over the intended range of operation. In conclusion, CFD-based design optimization greatly expedited and facilitated the completion of the PediaFlow® flow path and contributed to the system-wide optimization to produce a miniature maglev pump with exceptional hemocompatibility.

Development of a flow rate monitoring method for the wearable ventricular assist device driver

2014 ◽  
Vol 18 (2) ◽  
pp. 106-113 ◽  
Author(s):  
Kentaro Ohnuma ◽  
Akihiko Homma ◽  
Hirohito Sumikura ◽  
Tomonori Tsukiya ◽  
Yoshiaki Takewa ◽  
...  
Keyword(s):  
Flow Rate ◽  
Ventricular Assist Device ◽  
Device Driver ◽  
Assist Device ◽  
Monitoring Method ◽  
Ventricular Assist

Performance Study on Newly Developed Impellers for a Left Ventricular Assist Device

2007 ◽  
Vol 30 (7) ◽  
pp. 594-603
Author(s):  
C-H. Hsu
Keyword(s):  
Flow Rate ◽  
Left Ventricular Assist Device ◽  
Ventricular Assist Device ◽  
Pressure Head ◽  
Left Ventricular ◽  
Efficient Design ◽  
Performance Study ◽  
Assist Device ◽  
Ventricular Assist ◽  
Left Ventricular Assist

Our research develops a performance study on newly developed impellers for a left ventricular assist device. In order to analyze the hemodynamic characteristics of blood flow through the ventricular assist device, the CFX-TASCflow software is adopted to investigate the flow-field characteristics. The numerical results provide not only the flow characteristics for the overall field, but also the data of relationship for flow rate and pressure head. In the conceptual design process, hemodynamic study for an initial impeller design is presented first and a geometry change is recommended. Two design models are developed and the associated flow rate and pressure head performances are evaluated as well. According to design criteria, the most efficient design is the one with a smooth flow passage and with a low possibility for vortex generation. We suggest the superior design be chosen for further in vitro testing and be prepared for the new design generation. It has been shown that the design can provide a flow rate of 3.0 l/min with a pressure head of 127.09 mmHg. Both the flow rate and pressure head can meet requirements for the left ventricular assist device to work normally. (Int J Artif Organs 2007; 30: 594–603)

Evaluation of clinically relevant operating conditions for left ventricular assist device investigations

2020 ◽  
pp. 039139882093292
Author(s):  
A Wisniewski ◽  
D Medart ◽  
F-H Wurm ◽  
B Torner
Keyword(s):  
Boundary Conditions ◽  
Flow Rate ◽  
Ventricular Assist Device ◽  
Pressure Head ◽  
Ventricular Assist Devices ◽  
Experimental Investigations ◽  
Assist Device ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Term Data

Standardized boundary conditions for flow rate and pressure difference are currently not available for the development and certification process of ventricular assist devices. Thus, interdisciplinary studies lack comparability and quantitative assessment. Universally valid boundary conditions could be used for the application of numerical and experimental investigations and the approval procedure of ventricular assist devices. In order to define such boundaries, physiological data from INCOR® patients were evaluated. A total of 599 out of possible 627 ventricular assist device patients were analyzed regarding their cardiac demands of flow rate and pressure head. An analysis of long-term data was performed, in order to provide respective, static mean values for benchmark testing. Furthermore, the short-term data of 188 patients delivered field data-based dynamic flow and pressure curves. The results of the study revealed physiologically reasonable boundary conditions, which can be applied in numerical or experimental investigations of ventricular assist devices. For steady flow analysis, single values for flow rate (4.46 L/min) and pressure head (62 mmHg) are suggested. For the support of pulsatile and unsteady flow studies, seven typical patients and one representative dynamic curve for flow rate and pressure head are proposed. The standardized results provided in this article, can be used in favor of interdisciplinary comparability of future numerical computations or in vitro ventricular assist device tests in research, development, and approval.

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