Transient studies of a 3D aero-shaped tilting-disc valve in pulsatile flow

Abstract

A new 3D prosthetic valve design method is proposed which fully utilizes the aeronautic wing design guidelines. The design objective of this aero-shaped valve (ASV) aims at lowering the valve-induced blood damage and minimizing the impact momentum between occluder and valve strut. Unlike the past valve designs which relied on trial-and-error process, the present design uses analytic methods and stresses the transvalvular flowfield quality. Not only occluder configuration is examined in detail, but the influence of pivot location is accounted for. Based on the theory of wing sections and the analogy of flight stability, a concurrent occluder shape and rotation center optimization is accomplished. This optimization procedure, which integrates Computational Fluid Dynamics (CFD), Artificial Neural Network (ANN), and Genetic Algorithm (GA), is developed to search for a low-thrombogenic occluder shape and a permissible rotating center position. Comparing the optimized ASV to the conventional plate-like occluders, ASV encompasses better hemodynamic characteristics in terms of lower transvalvular pressure gradient and turbulence Reynolds stresses.