Combining the M1 constitutive law for the leaflet and the exponential law for chordae tendineae provides the most suitable simulation of mitral valve dynamics with fluid-structure interaction.
The choice of constitutive laws for mitral leaflets and chordae tendineae significantly impacts fluid-structure interaction simulation outcomes like regurgitation volume and orifice area.
In this paper, three different constitutive laws for mitral leaflets and two laws for chordae tendineae are selected to study their effects on mitral valve dynamics with fluid-structure interaction. We first fit these three mitral leaflet constitutive laws and two chordae tendineae laws with experimental data. The fluid-structure interaction is implemented in an immersed boundary framework with finite element extension for solid, that is the hybrid immersed boundary/finite element(IB/FE) method. We specifically compare the fluid-structure results of different constitutive laws since fluid-structure interaction is the physiological loading environment. This allows us to look at the peak jet velocity, the closure regurgitation volume, and the orifice area. Our numerical results show that different constitutive laws can affect mitral valve dynamics, such as the transvalvular flow rate, closure regurgitation and the orifice area, while the differences in fiber strain and stress are insignificant because all leaflet constitutive laws are fitted to the same set of experimental data. In addition, when an exponential constitutive law of chordae tendineae is used, a lower closure regurgitation flow is observed compared to that of a linear material model. In conclusion, combining numerical dynamic simulations and static experimental tests, we are able to identify suitable constitutive laws for dynamic behaviour of mitral leaflets and chordae under physiological conditions.
Cai et al. (Wed,) conducted a other in Mitral valve dynamics. Constitutive laws for mitral valve simulation vs. Alternative constitutive laws was evaluated on Mitral valve dynamics (orifice area, regurgitation flow, stress/strain). Combining the M1 constitutive law for the leaflet and the exponential law for chordae tendineae provides the most suitable simulation of mitral valve dynamics with fluid-structure interaction.