抄録
The purpose of this study is to examine the relationship between the flow condition and hemolysis level by integrating hemolysis test, flow visualization and computational fluid dynamics(CFD)to establish design criteria for the good hemocompatible centrifugal pump. Axial and radial gaps between the impeller tip and casing wall of Nikkiso centrifugal blood pump were modified independently and flow condition and hemolytic property of these pumps were examined. Examined gaps were 1.5, 1.0, and 0.5 mm for axial gap and 3.0, 2.0, 1.0, and 0.5 mm for radial gap, respectively. The pumps with the axial gap of 0.5 mm and the radial gap of 0.5 mm showed higher hemolysis level than the other pumps showed. Maximum shear stress in the pump, estimated by CFD, were increased by decreasing the radial gap from 3.0 to 0.5 mm. Regional flow pattern change at the tongue region by decreasing radial gap was observed by flow visualization. Gaps between impeller tip and casing wall are dominant factors to determine hemolytic property of the centrifugal pump. Relationship between regional flow pattern and blood trauma should be investigated in the future.
