Computational mechanics of the heart. (English) Zbl 1071.74659

Nash, M. P.; Hunter, P. J.

J. Elasticity 61, No. 1-3, 113-141 (2000).

Summary: Finite elasticity theory combined with finite element analysis provides the framework for analysing ventricular mechanics during the filling phase of the cardiac cycle, when cardiac cells are not actively contracting. The orthotropic properties of the passive tissue are described here by a ‘pole-zero’ constitutive law, whose parameters are derived in part from a model of the underlying distributions of collagen fibres. These distributions are based on our observations of the fibrous-sheet laminar architecture of myocardial tissue. We illustrate the use of high order (cubic Hermite) basis functions in solving the Galerkin finite element stress equilibrium equations based on this orthotropic constitutive law and for incorporating the observed regional distributions of fibre and sheet orientations. Pressure-volume relations and 3D principal strains predicted by the model are compared with experimental observations. A model of active tissue properties, based on isolated muscle experiments, is also introduced in order to predict transmural distributions of 3D principal strains at the end of the contraction phase of the cardiac cycle. We end by offering a critique of the current model of ventricular mechanics and propose new challenges for future modellers.

MSC:

74L15	Biomechanical solid mechanics
74S05	Finite element methods applied to problems in solid mechanics
92C10	Biomechanics

Keywords:

finite elastic deformation; cardiac mechanics; orthotropic constitutive relations; fibrous-sheet tissue structure