Three-dimensional fluid-structure interaction simulation of the Wheatley aortic valve

Author(s)

Oliveira, Hugo L. ; Buscaglia, Gustavo C. ; Paz, Rodrigo R. ; Del Pin, Facundo ; Cuminato, Jose A. ; Kerr, Monica ; Mckee, Sean ; Stewart, Iain W. ; Wheatley, David J.

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING; v. 40, n. 2, p. 24-pg., 2023-11-27.

Abstract

Valvular heart diseases (such as stenosis and regurgitation) are recognized as a rapidly growing cause of global deaths and major contributors to disability. The most effective treatment for these pathologies is the replacement of the natural valve with a prosthetic one. Our work considers an innovative design for prosthetic aortic valves that combines the reliability and durability of artificial valves with the flexibility of tissue valves. It consists of a rigid support and three polymer leaflets which can be cut from an extruded flat sheet, and is referred to hereafter as the Wheatley aortic valve (WAV). As a first step towards the understanding of the mechanical behavior of the WAV, we report here on the implementation of a numerical model built with the ICFD multi-physics solver of the LS-DYNA software. The model is calibrated and validated using data from a basic pulsatile-flow experiment in a water-filled straight tube. Sensitivity to model parameters (contact parameters, mesh size, etc.) and to design parameters (height, material constants) is studied. The numerical data allow us to describe the leaflet motion and the liquid flow in great detail, and to investigate the possible failure modes in cases of unfavorable operational conditions (in particular, if the leaflet height is inadequate). In future work the numerical model developed here will be used to assess the thrombogenic properties of the valve under physiological conditions. In this study, we propose a Finite Element Model that represents the mechanical behaviour of the Wheatley aortic valve in operational conditions. The model takes into account the large amplitude of the displacements and uses strong Fluid-Structure Interaction techniques to solve the coupled governing equations. Non-linear surface-to-surface contact models are also considered in order to assure good operation in the diastolic regime. The results show the proposed numerical model is able to reproduce the experimentally observed data with a good degree of agreement. It was seen that the Wheatley valve preserves a stable equilibrium position under controlled flow and pressure conditions.image (AU)

• FAPESP's process: 21/11129-0 - Mathematical modeling and numerical simulation of the Wheatley heart valve
• Grantee: Hugo Luiz Oliveira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/07375-0 - CeMEAI - Center for Mathematical Sciences Applied to Industry
• Grantee: Francisco Louzada Neto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC