Characterization of mechanical properties of pericardium tissue using planar biaxial tension and flexural deformation

Abstract

Flexure is an important mode of deformation for native and bioprosthetic heart valves. However, mechanical characterization of bioprosthetic leaflet materials has been done primarily through planar tensile testing. In this study, an integrated experimental and computational cantilever beam bending test was performed to characterize the flexural properties of glutaraldehyde-treated bovine and porcine pericardium of different thicknesses. A strain-invariant based structural constitutive model was used to model the pericardial mechanical behavior quantified through the bending tests of this study and the planar biaxial tests previously performed. The model parameters were optimized through an inverse finite element (FE) procedure in order to describe both sets of experimental data. The optimized material properties were implemented in FE simulations of transcatheter aortic valve (TAV) deformation. It was observed that porcine pericardium TAV leaflets experienced significantly more flexure than bovine when subjected to opening pressurization, and that the flexure may be overestimated using a constitutive model derived from purely planar tensile experimental data. Thus, modeling of a combination of flexural and biaxial tensile testing data may be necessary to more accurately describe the mechanical properties of pericardium, and to computationally investigate bioprosthetic leaflet function and design.

Computational Modeling of Human Bicuspid Pulmonary Valve Dynamic Deformation in Patients with Tetralogy of Fallot

“…The open area (Fig. 8(a)) is similar to that reported in literature [Jermihov, Jia, Sacks et al (2011); Murdock, Martin and Sun (2018)]. Due to the abnormal morphology of the valve caused by fusion of the two leaflets, the cusp showed significant eccentricity during peak systolic period (see Fig.…”

Fluid–Structure Interaction Models of Bioprosthetic Heart Valve Dynamics in an Experimental Pulse Duplicator

“…The parameter  2 [0, 1 3 ] describes collagen fiber angle dispersion. If  = 0, the fibers are perfectly aligned and the constitutive model becomes the same as that of Murdock et al [43] By contrast, if  = 1 3 , then the model describes an isotropic distribution of fibers, and we obtain an isotropic model with no preferred direction of fiber reinforcement. The parameters for the porcine aortic valve are fit to experimental tensile test data from Billiar and Sacks [35,36] for glutaraldehyde-fixed porcine aortic valves ( Fig.…”

“…in which F = J 1/3 F and J = det F. We use a modified version of the Holzapfel-Gasser-Ogden model from Murdock et al [43] with the addition of angle dispersion [44]. The isochoric part of the model, W (F), includes an isotropic contribution from the extracellular matrix and an anisotropic contribution from the collagen fibers embedded in the leaflets,…”

PRGF-Modified Collagen Membranes for Guided Bone Regeneration: Spectroscopic, Microscopic and Nano-Mechanical Investigations

“…By this technique, thin films consisting of randomly-oriented collagen fibrils were obtained, with the diameter varying from 300 nm up to 700 nm. The surface topography may play an important role in cellular response to collagen [38,39].…”