Flow visualization analysis of a monopivot centrifugal blood pump developed by MERA

A circulatory assist pump, which can be used for around two weeks after an operation, is under development by MERA. For R&D of a centrifugal blood pump it is important to prevent the thrombus formation caused by low shear stress and the hemolysis caused by high shear stress. Flow visualization analysis was performed around the pivot to prevent thrombus formation. We analyzed horizontal and vertical section around the pivot and enough washout to prevent thrombus formation was verified. In addition, a slight stagnant region was found in the outlet section and a relatively weak jet in the impeller tip region. Hemolysis tests were conducted also under the conditions of 100mmHg-5L/min and 200mmHg-5L/min. Hemolysis index, NIH, was 150% of BPX-80 under the condition of 100mmHg-5L/min, and 80% of BPX-80 under the condition of 200mmHg-5L/min. The hemolysis rate improves for high pressure conditions.