Study of the influence of blade angle distribution on hemodynamic and hemocompatibility performance in a miniature axial blood pump.

Abstract

High shear stress and turbulence in a miniature axial blood pump are affected by the pump's blade structure. which impacts the pump's hemodynamics and hemocompatibility performance. This study designed blades for a miniature axial blood pump via computational fluid dynamics (CFD). The optimal blade angle distribution must improve hemodynamic and hemocompatibility performance under the designed operating conditions (45,000 rpm rotational speed and 3 L/min flow rate). First, the blade inlet angles β1 were varied from -100° to -220°. Second, using the optimal β1, the blade angle distribution was changed by setting different curvatures at different curvature positions. Finally, the relationships among blade angle distribution parameters and hemodynamic, hemolysis, and thrombosis risk were analyzed. The results indicated that angle distribution should avoid positive curvature, and that "the absolute value of negative curvature percentage should increase progressively with the increasing of curvature position." Compared with the original impeller, the CFD and experimental results revealed an optimized impeller with a 17.4% increase in pressure head, a 2.1% increase in hydraulic efficiency, an 8.4% decrease in hemolysis index, and a 5.3% decrease in volume-averaged scaled activated platelet concentration. CFD-guided blade angle optimization can improve the hemodynamic and hemocompatibility performance of miniature axial blood pumps.