A pseudo active kinematic constraint for a biological living soft tissue: an effect of the collagen network

TL;DR

This paper introduces a finite element model incorporating a pseudo-active kinematic constraint to simulate the collagen network's effect on soft tissue deformation, accurately capturing wall thickening in cardiac tissues.

Contribution

It develops a novel 3D finite element model that includes a pseudo-active constraint to represent collagen network effects in soft tissues, enhancing understanding of tissue mechanics.

Findings

Model accurately predicts wall thickening in cardiac tissue.

Finite element results agree with analytical solutions.

Numerical simulations match experimental observations.

Abstract

Recent studies in mammalian hearts show that left ventricular wall thickening is an important mechanism for systolic ejection and that during contraction the cardiac muscle develops significant stresses in the muscular cross-fiber direction. We suggested that the collagen network surrounding the muscular fibers could account for these mechanical behaviors. To test this hypothesis we develop a model for large deformation response of active, incompressible, nonlinear elastic and transversely isotropic living soft tissue (such as cardiac or arteries tissues) in which we include a coupling effect between the connective tissue and the muscular fibers. Then, a three-dimensional finite element formulation including this internal pseudo-active kinematic constraint is derived. Analytical and finite element solutions are in a very good agreement. The numerical results show this wall thickening effect with an order of magnitude compatible with the experimental observations.