Abstract
We have developed a hydrodynamically levitated centrifugal blood pump with a disposable pump head for extracorporeal circulatory support. This pump has three thrust bearing gaps; top bearing gap, outer-bottom bearing gap and inner-bottom bearing gap. The purpose of this study is experimentally to evaluate the effect of the thrust bearing gap on hemolytic property of a hydrodynamically levitated centrifugal blood pump for hemolysis reduction. We compared the three kinds of pump models that have different impeller levitation positions by changing the top shroud area. Firstly, we conducted the thrust bearing gap measurement using a laser focus displacement meter. Secondly, in vitro hemolysis test was performed using bovine blood at a pressure head of 200 mmHg and a flow rate of 4.0 L/min for 2 hours. As a result, it was found that the outer-bottom bearing gap was more effective on hemolysis than the top and inner-bottom bearing gaps.
