Effect of segmented polyurethane coating on thrombus regulated with pulsatile shear flow

The effect of segmented polyurethane coating on thrombus formation was quantitatively studied under a shear field in vitro. Segmented polyurethane, has been applied to coat the inner surface in blood pumps in artificial hearts. Here, the Couette-type of shear rate was applied to canine blood between concave and the convex cones. The material of the cones was varied: polymethyl-methacrylate, polyvinyl chloride, and polyvinyl chloride coated with segmented polyurethane. The study shows that the clotting time extends on the segmented polyurethane especially at the higher shear rates, although the clot ratio is at the same level as that without coating. This clotting time extension should regulate thrombus formation under pulsatile shear flow.