Biomedical Simulations of Healthy and Pathological Aortic Valves: Fluid-Structure Interaction using Coupled FE and Lattice Boltzmann Approach

The aortic valve (AV), located between the left ventricle and the aorta, is responsible for maintaining an outward unidirectional flow. A common AV congenital disease is the form of bicuspid aortic valve (BAV). This anatomical abnormality (0.5-2% of the population) elevates the stresses and deformations in the cusps. This initiates a calcific aortic valve disease (CAVD). The latter is a progressive disease characterized by calcification growth in the AV cusps leading to thickening and stiffening of their tissues.

This study examines a new hemodynamic-structural co-modeling approach using Lattice-Boltzmann (LBM) and Finite-Element (FE) methods. The applied LBM is a mesh-less method based on the kinetic gas theory of particles used to simulate fluid flow. The proposed new fluid-structure interaction (FSI) approach is used to investigate healthy and pathological aortic valves. Towards that goal, FE-LBM FSI models of TAV and BAVs under physiological pressure are studied. Different parameters have been examined, such as effective orifice area, hemodynamic metrics and stress magnitudes. The new FE-LBM approach is examined in its ability to enhance the current FSI-CFD future modeling aspects in-part by introducing multi-scale capabilities.