FLUID-MECHANICAL ANALYSIS OF A PROSTHETIC HEART VALVE IN OUR VENTRICULAR ASSIST DEVICE (VAD) WITH A USE OF THE FLOW VISUALIZATION TECHNIQUE

Abstract

It is very important to grasp the flow characteristics of a prosthetic valve on the various driving conditions in order to develop a VAD. Therefore, the fluidmechanical property of Björk-Shiley prosthetic valve (BS-21ABP, spherical) was analized by means of the quantitative flow visualization technique. The flow visualizations were carried out on the four different flow rate conditions (3.0, 2.0, 1.5 and 1.0 1/min). It was observed that the decrease of flow rate effected not on the maximum velocity but on the velocity vector distributions. On the low flow rate condition (1.0 1/min), the decreases of the flow velocity and the shear rate, which could cause the thrombus formation, were observed in a minor-orifice and its lower part. In conclusion, it is necessary to keep the VAD flow rate more than 1.5 1/min to prevent the thrombus formation on the prosthetic valve.