轴流血泵最佳左心辅助下的速度变化及内流场分析

In order to solve the phenomenon of suction or regurgitation under constant pressure or constant speed assistance of axial flow blood pump, the self-developed aortic valve axial flow blood pump was taken as the research object to establish the multi-scale parametric model with "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 flow blood pump produces 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 assistance 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.