Evaluation of shear and recirculation in centrifugal artificial heart by flow visualization

A centrifugal blood pump for artificial heart has to have low hemolysis and no thrombus formation. For finding and removing the fluid dynamic causes of the above mentioned phenomena, flow visualization was utilized, as flow visualization can identify the high shear and stagnation locations which relate to hemolysis and thrombus formation respectively. In the present paper, general fluid dynamic characteristics of centrifugal blood pumps will be extracted, through analyzing four typical centrifugal pumps with flow visualization technique. Finding shear in the volute and diffuser regions, confirming vortex formation at washout holes, and quantitative analysis of the flow in the inlet regions are the shown examples. The obtained results correspond well to hemolysis tests, which proves that flow visualization is a useful tool in developing and analyzing blood pumps for artificial hearts.