Blood Flow Downstream of a Dysfunctional Mechanical Heart Valve

Dysfunctional mechanical heart valves cause mortality of a great number of patients around the world. One of the treatments is replacement of malfunctional heart valve with mechanical heart valve (MHV). Yet, thrombus formation threatens the functionality of the replaced valve. Although probability of thrombus formation is not high, it is one of the most severe heart complications. In this experiment, a system simulating a left heart including a silicon-ventricle fixed in an acrylic chamber, was used. The ventricle was contracted as a result of the pushed fluid by a piston inside the simulating system. The fluid was a solution of water and glycerol, 60% and 40%, respectively with a density of 1090Kg/m³ and a dynamic viscosity of 4 x 10^-2 Pa.s. Time resolved PIV (Particle Image Velocimetry) measurement was taken along the central plane of the left ventricle. The experiment was repeated for four different valve conditions. Velocity profiles were obtained and normalized with respect to the average velocity of corresponding profile. Viscus energy dissipation and accumulation of sheer stress were computed for all the four cases. The most severe case (one blocked leaflet) showed the highest velocity, energy dissipation and accumulation of shear stress.