Numerical and experimental measurements of the flow through mechanical heart valves in the natural and artificial heart

The flow patterns of the blood passing through tilting disk and bileaflet mechanical valves in the mitral position of ventricle assist device (VAD) and of the natural left ventricle, were investigated both numerically and experimentally. An experimental Continuous Digital Particle Imagining Velocimetry (CDPIV) was combined with a computational fluid dynamics (CFD) analysis. These tools complement each other to result into a comprehensive description of the complex 3D, viscous and time-dependent flow field inside the blood chambers. the main result was that the flow field across the MHV was mainly affected by the valve type and the inflow conditions. Tilting disk valve induced a large rotating flow that filled the complete chamber, however, bileaflet valve induced two counter-direction vortices in the chamber.