This paper on "The Finite Element Analysis of a Polyurethane Tri-Leaflet Heart Value" was presented at the NAFEMS World Congress on Design, Simulation & Optimisation: Reliability & Applicability of Computational Methods - 9-11 April 1997, Stuttgart, Germany.

Abstract

The emergence of synthetic materials as suitable candidates for biocompatible applications has been reported in recent years. This paper highlights the use of finite element methods to obtain an understanding of the mechanical behaviour developed in a polyurethane tri-leaflet heart valve. The valve geometry is such that the leaflet profile is elliptical in the radial direction and hyperbolic in the circumferential direction. Polyurethane is, by nature, a highly nonlinear material with the ability to exhibit elastic response to large levels of strain. In view of the significant geometric and material nonlinearities, finite element modelling of a polyurethane heart valve presents some difficulties. Opening and closing phases of the leaflet's behaviour have been simulated by applying uniform leaflet pressures of 10mmHg and 80mmHg respectively. Incidences of high stress regions and coaptation zones are presented herein. Characterisation of the material's nonlinear elastic and time-dependant behaviour is currently underway. Temperature and strain rate sensitive tests are also being carried out.