Using additively manufactured compression moulds to produce polymer heart valves with variable leaflet thickness

Department of Mechanical Engineering and Mechatronics Engineering, Central University of Technology, Free State, South Africa

^* Corresponding author: rmasheane@cut.ac.za

Abstract

The durability of polymer valve lifespan can be impacted by fatigue-induced leaflet deterioration. One effective way to reduce the risk of fatigue failure is by increasing the thickness of the leaflets along the belly curve. A study indicates that valves manufactured using the dip moulding method, displayed thinner thickness at the belly of the valve and experienced a higher stress concentration in that area. This implies that a carefully regulated varying thickness could play a crucial role in optimizing the valve hemodynamic performance and enhancing its longevity. The additive manufacturing process was utilized to manufacture the complex and intricated Ti6Al4V (ELI) static and dynamic assemblies of the compression mould. The process and moulding parameters that facilitated the fabrication of an experimental valve prototype were ascertained. Scanning electron microscopy studies were performed to confirm the obtained wall thickness using thickness measuring instruments and to evaluate the surface topography of the leaflet’s surfaces. The valves were subjected to tensile testing to examine the fundamental mechanical properties of the valve and compared with natural valves.