Development of a test bank for fluid dynamic analysis of two prosthetic heart valves using air as working fluid

This work presents the fluid dynamic analysis of the mechanical prosthetic heart valves: Björk Shiley and Sorin Bicarbon™. Analysis of prosthetic valves is currently done with viscous fluids that emulate the behavior of blood; however the developed test bank, wind tunnel, uses air as the working fluid. This working fluid differs from those currently being used due to its low density and viscosity properties, which provides greater sensitivity to small changes in geometry and valve design variations. These features permit to identify relevant changes to the patient's hemodynamic system based on the effect of the implanted valve. Tests were performed by measuring the fluid-dynamics of both valves; the obtained results show accuracy with the valves' performance under clinical conditions. The offset design of the Björk Shiley tilting disk gives the valve the ability to generate less blood trauma and increase laminar flow and the Sorin Bicarbon™ bileaflet has a larger orifice for better hemodynamic performance. Furthermore, the transversal pressure gradients and local effects such as turbulence and vortexes were also analyzed; and the obtained results are accurate according to the functionality, geometrical and structural characteristics of both valves at their real environment.