Abstract
We have previously developed a compact centrifugal blood pump directly driven by a miniature DC-servo motor for extracorporeal and cardiac assisted circulation. Through in vitro tests, it has been proved that the semi-open type impeller with inlet and outlet blade angle of respective 20° and 50° is the most adequate with regard to the pump characteristics and the degree of hemolysis. In this report, the effect of the pump casing on the pump performances was evaluated to determine an optimum shape of the pump casing. It was demonstrated that the flow characteristics and the degree of hemolysis of the pump with volute casing were significantly improved at higher region of flow rate compared with those of the pump without volute casing. It was suggested through this study that the optimum design of the blood pump should be made in accordance with the range of flow rate required.
