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Analysis of speed and internal flow field of axial flow blood pump in optimal left heart assistance |
JING Teng1*, GU Lingyu1, WANG Fangqun2, HE Zhaoming1,3 |
1. National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 3. Department of Mechanical Engineering, Texas Tech University, Lubbock 79409, USA |
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Abstract In order to solve the phenomenon of suction or regurgitation under constant pressure or constant speed assistance of axial blood pump, the self-developed aortic valve axial blood pump was taken as the research object to establish the multi-scale parametric model, ″axial flow blood pump-blood circulation system″ in series coupling, which presents the curve of the rotating speed reaching the optimal assisted state under the condition of heart failure at all levels. Compared to constant speed assistance, the hemodynamic results obtained by the variable speed assistance were more fitted to the normal heart. CFD technology was used to compare and analyze the internal flow field of two auxiliary states in one cardiac cycle under grade Ⅳ heart failure. It is found that under the assistance of variable speed, the axial blood pump produced obvious eddy current in the isovolumic systolic period, isovolumic diastolic period and filling period, and the flow passage time is longer, but the shear stress is smaller, and hemolysis will not be produced. During the ejection period, the variable-speed assisted flow is more stable, and no vortex is generated, but its shear stress is higher than the critical value of 500 Pa in the time period of 0.10 s and hemolysis does not occur.
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Received: 15 January 2019
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