A COMPUTATIONAL TOOL FOR THE OPTIMIZATION OF A NEW POLYMERIC HEART VALVE PROSTHESIS

• Published in: International journal of artificial organs 2014-01, Vol.37 (8), p.622-623
• Main Authors: Serrani, M, Stasiak, J, Brubert, J, De Gaetano, F, Moggridge, G D, Costantino, M L
• Format: Article
• Language: English
• Subjects: Computation; Computer programs; Design analysis; Heart valves; Mathematical models; Orientation; Stress concentration; Valves
• ISSN: 0391-3988
• DOI: 10.5301/ijao.5000347

Aim: A new polymer prosthetic heart valve (PHV) made of styrenic block copolymers was developed. Regions of stress concentration on heart valves leaflets have been suggested as a factor leading to structural failure. The aim of this work was the development of a computational tool to optimize the PHV design and structure, minimizing stress concentration on the valve leaflets. Methods: A geometrical model representing 1/3 of the PHV which allowed the control of the valve design parameters (e.g. leaflet thickness and curvature) was developed. The polymer mechanical behaviour was described by a hyperelastic anisotropic constitutive law which includes the material microstructural description. The material parameters were optimized on experimental data. A routine was implemented to optimize the polymer chains orientation in the PHV leaflet; the routine defined the orientation along the maximum principal stress direction by an iterative procedure. Suitable kinematic constraints were applied to the structure, while a uniform pressure up to 180 mmHg was defined on the leaflet to simulate the valve closure. Results: The valve leaflet was subjected to lower stress if the polymer chains orientation was optimized. The model also allowed the evaluation of the stress distribution among different valve designs, giving fundamental information for manufacturing. Conclusions: The developed computational model represents a sound tool to optimize the PHV design and structure.