ANALYSIS OF FLOW PATTERN IN THE VICINITY OF PROSTHETIC HEART VALVES BY MEANS OF LASER-DOPPLER ANEMOMETER.

Fluid mechanical characteristics of blood flow in the vicinity of prosthetic heart valves are investigated by in vitro experiments using a laser-Doppler anemometer (LDA) under pulsatile flow condition. Average flow velocity and root mean square disturbance velocity at each point are obtained by a phase average method. Cross-sectional velocity distributions are plotted 3-dimensionally by computer analyses of LDA data, by which one can observe the overall feature of valve flow not only quantitatively but also visually. Rod-like fluid flow throughout the cross-section is observed in the early systolic phase and then a cylindrical jet flow rapidly appears along the inner wall of model aorta in CC Bjoerk-Shiley valve.