抄録
The purpose of this study is to develop the next-generation cascade blood pump for a total artificial heart. A cascade pump can achieve a high pressure rise by giving centrifugal forces to a fluid repeatedly along its U-shaped flow channel. Meanwhile, the pressure difference between the inlet and the outlet produces the radial deflection of the impeller shaft, which can remarkably decrease the durability of the pump. To reduce the deflection, we have developed the 4-channel cascade pump, in which the two flow channels on each side of the impeller are symmetrically arranged with respect to the impeller shaft, so that the radial deflection caused by unbalanced pressure distributions can be canceled. The 4-channel cascade pump, inclusive of a brushless DC motor, is 70 mm in outside diameter and 30 mm in thickness. The 4-channel cascade pump provides 15 L/min against 100 mmHg at 3,000 rpm. To evaluate the hemolytic characteristics of the 4-channel cascade pump, we conducted an in vitro hemolysis test for 2 hours using a mock circulatory loop. Normalized index of hemolysis was 0.036 g/100L. We will try to improve the hemocompatibility of the 4-channel cascade pump.
