Non-linear rotation-free shell finite-element models for aortic heart valves

Area of Science:

• Computational mechanics
• Biomedical engineering
• Materials science

Background:

• Aortic heart valve function is critical for cardiovascular health.
• Accurate simulation of heart valve dynamics requires sophisticated material models.
• Previous studies have utilized various hyperelastic models with limitations.

Purpose of the Study:

• To compare the performance of Saint-Venant and May-Newmann-Yin (MNY) hyperelastic material models in dynamic aortic heart valve simulations.
• To investigate the impact of non-linear anisotropic material behavior on heart valve dynamics, particularly during leaflet interaction and valve closure.
• To establish an efficient finite element (FE) framework for simulating biological tissues in cardiovascular applications.

Main Methods:

• Incorporation of hyperelastic material models into a rotation-free, large deformation, shell finite element (FE) formulation.
• Dynamic simulations of aortic heart valve using Saint-Venant and MNY material models.
• Verification of model formulation and implementation through uniaxial tests.
• Analysis of leaflet interactions during the closing phase of the heart valve at the end of systole.

Main Results:

• The study quantitatively demonstrates the critical role of non-linear anisotropic models in achieving a proper dynamic response of the heart valve.
• Comparison revealed significant differences in simulation outcomes between the Saint-Venant and MNY models, particularly concerning leaflet interactions.
• The developed FE framework proved efficient for simulating biological tissues.

Conclusions:

• Non-linear anisotropic hyperelastic models are essential for accurate dynamic simulations of aortic heart valves, especially during the closing phase.
• The developed finite element framework provides an efficient tool for simulating biological tissues.
• This work advances the potential for high-fidelity flow-structure interaction simulations of native and bioprosthetic aortic heart valves.