Characterization of three-dimensional anisotropic heart valve tissue mechanical properties using inverse finite element analysis. (September 2016)

• Record Type: Journal Article
• Authors: Abbasi, Mostafa; Barakat, Mohammed S.; Vahidkhah, Koohyar; Azadani, Ali N.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 62(2016)
• Page Start: 33
• Page End: 44
• Publication Date: 2016-09
• Subjects: Inverse finite element simulation -- Medical device -- Heart valves -- Stress -- Three-dimensional anisotropic mechanical properties -- Fung constitutive model -- Viscous damping coefficient; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2016.04.031
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: Computational modeling has an important role in design and assessment of medical devices. In computational simulations, considering accurate constitutive models is of the utmost importance to capture mechanical response of soft tissue and biomedical materials under physiological loading conditions. Lack of comprehensive three-dimensional constitutive models for soft tissue limits the effectiveness of computational modeling in research and development of medical devices. The aim of this study was to use inverse finite element (FE) analysis to determine three-dimensional mechanical properties of bovine pericardial leaflets of a surgical bioprosthesis under dynamic loading condition. Using inverse parameter estimation, 3D anisotropic Fung model parameters were estimated for the leaflets. The FE simulations were validated using experimental in-vitro measurements, and the impact of different constitutive material models was investigated on leaflet stress distribution. The results of this study showed that the anisotropic Fung model accurately simulated the leaflet deformation and coaptation during valve opening and closing. During systole, the peak stress reached to 3.17 MPa at the leaflet boundary while during diastole high stress regions were primarily observed in the commissures with the peak stress of 1.17 MPa. In addition, the Rayleigh damping coefficient that was introduced to FE simulations to simulate viscous damping effects of surrounding fluid was determined. Graphical abstract: Highlights: An optimization approach was proposed to determine leaflets mechanical properties. Generalized anisotropic and orthotropic Fung constitutive models were used in the simulations. Biaxial stretching data were used to obtain initial estimates for the optimization. Leaflets motion was matched in the simulations with the experimental measurements. Leaflets maximum principal stress distribution was obtained under dynamic loading.