Analysis of a mechanical heart valve prosthesis and a native venous valve: Two distinct applications of FSI to biomedical applications

摘要

This paper reports the application of two commercial codes to the study of distinct cardiovascular problems: dynamics of a mechanical heart valve prosthesis and function of a native venous valve. The choice of code is driven by the characteristics of the problem. The ANSYS-CFX implicit finite volume code is employed for the mechanical valve where the solution is dominated by the interaction between the local fluid domain and the rigid valve leaflets. The LS-DYNA explicit dynamics code is used due to the stability of this approach when applied to systems with very flexible structural components such as the leaflets of a venous valve. The mechanical valve dynamics remain consistent for a range of mesh densities and residual criteria but begin to vary once the solution time step is increased above 2E-4 s. Venous valve function after application of a gravitational body load is shown to be dependent on parent vessel elastic modulus, E. The venous valve initially closes to a greater extent with a 'softer' parent vessel. Both approaches show promise for further study of these biomedical systems including the cavitation and thrombotic potential of mechanical valves and the local residence of blood constituents in the region of venous valve sinuses.