title: A comparative study of linear and nonlinear simulations of the leaflets in a bioprosthetic heart valve during the cardiac cycle.
abstract: Two geometrically identical models of the leaflets of a bicuspid bioprosthetic heart valve have been constructed using finite elements. The boundary conditions applied to the models were also identical but a linear material model has been used in one and a nonlinear elastic model in the other. The models were fullscale and contained 2600 Belytschko-Lin-Tsai shell elements which allowed the variation of stress through the thickness of the leaflet to be modelled. A time-varying, spatially-uniform pressure differential was applied across the leaflets to model their behaviour during a complete cardiac cycle. The simulation was performed using a dynamic, explicit, time-stepping, finite element code. A comparison of the two models showed that the nonlinear model was more responsive to the time-varying pressure wave, and deformed into more complex shapes during the opening and closing phases which induced lower compressive but higher tensile stresses in the leaflets.
authors.affiliation: Department of Mechanical and Process Engineering, University of Sheffield, UK.
authors.forename: E A
authors.initials: EA
authors.lastname: Patterson
authors.forename: I C
authors.initials: IC
authors.lastname: Howard
authors.forename: M A
authors.initials: MA
authors.lastname: Thornton
mesh_terms: D001705:Bioprosthesis; D006350:Heart Valve Prosthesis; D006801:Humans; D016014:Linear Models; D008943:Mitral Valve / Q000502:physiology; D008955:Models, Cardiovascular; D017711:Nonlinear Dynamics; D011474:Prosthesis Design; D013314:Stress, Mechanical