Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
Int J Numer Method Biomed Eng. 2023 Feb;39(2):e3671. doi: 10.1002/cnm.3671. Epub 2022 Dec 22.
To investigate the effect of rotor design configuration on hemodynamic features, hemocompatibility and dynamic balance of blood pumps. Computational fluid dynamics was employed to investigate the effects of rotor type (closed impeller, semi-open impeller), clearance height and back vanes on blood pump performance. In particular, the Eulerian hemolysis model based on a power-law function and the Lagrangian thrombus model with integrated stress accumulation and residence time were applied to evaluate the hemocompatibility of the blood pump. This study shows that compared to the closed impeller, the semi-open impeller can improve hemolysis at a slight sacrifice in head pressure, but increase the risk of thrombogenic potential and disrupt rotor dynamic balance. For the semi-open impeller, the pressure head, hemolysis, and axial thrust of the blood pump decrease with increasing front clearance, and the risk of thrombosis increases first and then decreases with increasing front clearance. Variations in back clearance have little effect on pressure head, but larger on back clearance, worsens hemolysis, thrombogenic potential and rotor dynamic balance. The employment of back vanes has little effect on the pressure head. All back vanes configurations have an increased risk of hemolysis in the blood pump but are beneficial for the improvement of the rotor dynamic balance of the blood pump. Reasonable back vanes configuration (higher height, wider width, longer length and more number) decreases the flow separation, increases the velocity of blood in the back clearance, and reduces the risk of blood pooling and thrombosis. It was also found that hemolysis index (HI) was highly negatively correlated with pressure difference between the top and back clearances (r = -.87), and thrombogenic potential was positively correlated with pressure difference between the top and back clearances (r = .71). This study found that rotor type, clearance height, and back vanes significantly affect the hydraulic performance, hemocompatibility and rotor dynamic balance of centrifugal blood pumps through secondary flow. These parameters should be carefully selected when designing and optimizing centrifugal blood pumps for improving the blood pump clinical outcomes.
为了研究转子设计结构对血液泵的血液动力学特性、血液相容性和动态平衡的影响。采用计算流体动力学方法研究了转子类型（闭式叶轮、半开式叶轮）、间隙高度和后叶片对血液泵性能的影响。特别地，基于幂律函数的欧拉溶血模型和集成应力积累和停留时间的拉格朗日血栓模型被应用于评估血液泵的血液相容性。本研究表明，与闭式叶轮相比，半开式叶轮可以在略微牺牲扬程的情况下改善溶血，但会增加血栓形成的风险并破坏转子的动态平衡。对于半开式叶轮，随着前间隙的增加，血液泵的扬程、溶血和轴向推力减小，血栓形成的风险先增加后减小。后间隙的变化对扬程影响不大，但后间隙越大，溶血、血栓形成倾向和转子动态平衡越差。后叶片的使用对扬程影响不大。所有后叶片配置都会增加血液泵的溶血风险，但有利于改善血液泵的转子动态平衡。合理的后叶片配置（更高的高度、更宽的宽度、更长的长度和更多的数量）可以减少流动分离，增加后间隙中血液的速度，并降低血液淤积和血栓形成的风险。还发现溶血指数（HI）与顶后间隙压差呈高度负相关（r = -.87），血栓形成倾向与顶后间隙压差呈正相关（r =.71）。本研究发现，通过二次流，转子类型、间隙高度和后叶片显著影响离心泵的水力性能、血液相容性和转子动态平衡。在设计和优化离心泵时，应仔细选择这些参数，以改善血液泵的临床效果。
