The effect of fundamental curves on geometric orifice and coaptation areas of polymeric heart valves

Abstract

Valvular diseases, such as aortic stenosis, are considered a common condition in the US. In severe cases, either mechanical or prosthetic heart valves are employed to replace the diseased native valve. The prosthetic heart valve has been a focal point for researchers to gain a better understanding of the mechanics, which will lead to improved longevity. In this study, our objective was to evaluate the effect of fundamental curves on the geometric orifice area and the coaptation area by implementing a two-level Taguchi Orthogonal Array (OA) design (Analysis of Variance (ANOVA) technique) and the interaction plots to investigate the individual contributions. The leaflet geometry was represented with the attachment curve, the free edge, and the belly curve. A total of three varying control coordinates were used to form different leaflet surfaces. With two different biocompatible polymers, 16 finite element models were prepared. Each model was subjected to time-varying transvalvular pressure. The results showed that the control coordinate for the belly curve has the highest impact on the coaptation area of the valve models with higher average 100% modulus. The geometric orifice area was affected by both control points of the attachment curve and the belly curve. A similar effect was also observed for the valve models with lower average 100% modulus.

Keywords: ANOVA; Coaptation area; Finite element model; Fundamental curves; Geometric orifice area; Polymeric heart valves.