HEMOLYSIS AND HEAT-GENERATION IN 6 DIFFERENT TYPES OF CENTRIFUGAL BLOOD PUMPS

What the most causative factor affecting hemolysis is still controvers ial. To resolve this problem, we investigated the relationship between hemolysis and heat generation in six types of centrifugal blood pumps (Bio-Pump, Delphin, Capiox, Nikkiso, Isoflow, and Toyobo). The analyz ed parameters were index of hemolysis in fresh goat blood, pumping per formance, and heat generation in a thermally isolated mock circuit. Th ese parameters were analyzed at a flow rate of 5 L/min by changing the pressure head (100 mm Hg and 500 mm Hg). At 500 mm Hg of pressure hea d, the Bio-Pump needed the highest rotation number and showed the high est hemolytic rate and heat generation. The index of hemolysis is well correlated to heat generation (r(2) = 0.721). Heat may originate from the motor by conduction, hydraulic energy loss, and mechanical fricti on between the shaft and seal. We strongly suspect that hemolysis was caused by a factor such as mechanical friction which generates heat lo cally.