title: Mass-spring model for simulation of heart valve tissue mechanical behavior.
abstract: Heart valves are functionally complex, making surgical repair difficult. Simulation-based surgical planning could facilitate repair, but current finite element (FE) studies are prohibitively slow for rapid, clinically oriented simulations. Mass-spring (M-S) models are fast but can be inaccurate. We quantify speed and accuracy differences between an anisotropic, nonlinear M-S and an efficient FE membrane model for simulating both biaxial and pressure loading of aortic valve (AV) leaflets. The FE model incurs approximately 10 times the computational cost of the M-S model. For simulated biaxial loading, mean error in normal strains is <1% for both FE and M-S models for equibiaxial loading but increases for non-equibiaxial states for the M-S model (7%). The M-S model was less able to simulate shear behavior, with mean strain error of approximately 80%. For pressurized AV leaflets, the M-S model predicts similar leaflet dimensions to the FE model (within 2.6%), and the coaptation zone is similar between models. The M-S model simulates in-plane behavior of AV leaflets considerably faster than the FE model and with only minor differences in the deformed mesh. While the M-S model does not allow explicit control of shear response, shear does not strongly influence shape of the simulated AV under pressure.
authors.affiliation: Department of Cardiac Surgery, Children's Hospital, Boston, MA, USA. peter.hammer@childrens.harvard.edu
authors.forename: Peter E
authors.initials: PE
authors.lastname: Hammer
authors.forename: Michael S
authors.initials: MS
authors.lastname: Sacks
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: del Nido
authors.forename: Robert D
authors.initials: RD
authors.lastname: Howe
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000502:physiology*; D003198:Computer Simulation; D006801:Humans; D008955:Models, Cardiovascular; D033081:Shear Strength / Q000502:physiology