An investigation of blood flow behavior and hemolysis in artificial organs.

In our previous study, in vitro hemolysis tests showed that collision flow against wall roughness had an effect on hemolysis when the flow velocity was more than 3 m/s and surface roughness was more than Ra = 1.54 microm. However, the specific portion of the flow on the wall that induced hemolysis was not clarified. Therefore, the purpose of this study was to present the relationship between flow behavior and hemolysis by means of in vitro tests and computational fluid dynamics (CFD) analysis. We investigated the relationship between the location of surface roughness and hemolysis. In CFD, we investigated the flow behavior on the wall. The highest rate of hemolysis was observed in a region around the center of the surface roughness on the bottom plate. On CFD analyses, the flow behavior included the highest wall shear stress (304 Pa) and the highest flow acceleration (2.8 m/s2) around the center of the bottom plate. Therefore, it is concluded that the causes of hemolysis during collision flow depend upon wall shear stress and flow acceleration.