3D Characterization of Transmitral Vortex using Defocusing Digital Particle Image Velocimetry

In this study, we have experimentally characterized the 3D vortex passing through a physiologically relevant model of mitral valve using Defocusing Digital PIV (DDPIV). The valve model was made of soft silicone with diameter of $25mm$, similar to the adult mitral valve. The mitral model possesses a large anterior and a small posterior leaflet that results in asymmetric formation of transmitral vortex. A piston-cylinder mechanism drives the flow and travels to produce a range of $L/D$ from $2$ to $6$. We have characterized the shape of the 3D vortex forming through the D-shaped orifice of a mitral valve using DDPIV technique. The evolution of the vortex has been illustrated for different stroke ratios.