Development of design methods for a centrifugal blood pump with a fluid dynamic approach: Results in hemolysis tests

The purpose of this study was to examine the relationship between local flo w conditions and the hemolysis level by integrating hemolysis tests, flow v isualization, and computational fluid dynamics to establish practical desig n criteria for centrifugal blood pumps with lower levels of hemolysis. The Nikkiso centrifugal blood pump was used as a standard model, and pumps with different values of 3 geometrical parameters were tested. The studied para meters were the radial gap between the outer edge of the impeller vane and the casing wall, the position of the outlet port, and the discharge angle o f the impeller vane. The effect of a narrow radial gap on hemolysis was con sistent with no evidence that the outlet port position or the vane discharg e angle affected blood trauma in so far as the Nikkiso centrifugal blood pu mp was concerned. The radial gap should be considered as a design parameter of a centrifugal blood pump to reduce blood trauma.