title: Characterization of three-dimensional anisotropic heart valve tissue mechanical properties using inverse finite element analysis.
abstract: Computational modeling has an important role in design and assessment of medical devices. In computational simulations, considering accurate constitutive models is of the utmost importance to capture mechanical response of soft tissue and biomedical materials under physiological loading conditions. Lack of comprehensive three-dimensional constitutive models for soft tissue limits the effectiveness of computational modeling in research and development of medical devices. The aim of this study was to use inverse finite element (FE) analysis to determine three-dimensional mechanical properties of bovine pericardial leaflets of a surgical bioprosthesis under dynamic loading condition. Using inverse parameter estimation, 3D anisotropic Fung model parameters were estimated for the leaflets. The FE simulations were validated using experimental in-vitro measurements, and the impact of different constitutive material models was investigated on leaflet stress distribution. The results of this study showed that the anisotropic Fung model accurately simulated the leaflet deformation and coaptation during valve opening and closing. During systole, the peak stress reached to 3.17MPa at the leaflet boundary while during diastole high stress regions were primarily observed in the commissures with the peak stress of 1.17MPa. In addition, the Rayleigh damping coefficient that was introduced to FE simulations to simulate viscous damping effects of surrounding fluid was determined.
authors.affiliation: The DU Cardiac Biomechanics Laboratory, Department of Mechanical and Materials Engineering, University of Denver, Denver, CO 80210, United States.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Abbasi
authors.affiliation: The DU Cardiac Biomechanics Laboratory, Department of Mechanical and Materials Engineering, University of Denver, Denver, CO 80210, United States.
authors.forename: Mohammed S
authors.initials: MS
authors.lastname: Barakat
authors.affiliation: The DU Cardiac Biomechanics Laboratory, Department of Mechanical and Materials Engineering, University of Denver, Denver, CO 80210, United States.
authors.forename: Koohyar
authors.initials: K
authors.lastname: Vahidkhah
authors.affiliation: The DU Cardiac Biomechanics Laboratory, Department of Mechanical and Materials Engineering, University of Denver, Denver, CO 80210, United States. Electronic address: Ali.Azadani@du.edu.
authors.forename: Ali N
authors.initials: AN
authors.lastname: Azadani
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D002417:Cattle; D003198:Computer Simulation; D020342:Finite Element Analysis; D006350:Heart Valve Prosthesis; D006351:Heart Valves / Q000502:physiology*; D006801:Humans; D008422:Materials Testing; D008955:Models, Cardiovascular; D013314:Stress, Mechanical
keywords: Fung constitutive model; Heart valves; Inverse finite element simulation; Medical device; Stress; Three-dimensional anisotropic mechanical properties; Viscous damping coefficient