Abstract
we devekoped a computer-controlled hydraulic mock circulator to investigate mechanism of motions of mechanical prosthetic heart valves and studied their in vitro motions under the flow condition controlled with high accuracy. The Omnicarbon valve, the Björk-Shiley valve and the Medtronic-Hall valve were tested at mitral position. These valves were driven under single-or double-peak flow condition and were photographed by a high speed CCD camera. Flowrate, BPM and S/D ratio were set as 4.0 L/min, 70 and 0.3, respectively. By analyzing the images of the valves we found: 1) there was no significant difference in motion among the three valves tested. 2) an unstable motion was observed as the decrease of inflow rate. 3) a temporary closure of the disc occurred at the least inflow rate between two inflow peaks.
