New approaches to computational modeling of the cardiac valves Conference Paper uri icon

abstract

  • The objective of this study was to develop new, more accurate computational models of soft tissues, particularly the aortic valve. Aortic valve tissue is a complex composite material, consisting of multiple layers of collagen, elastin and glycosaminoglycans. Computational models of such a material must thus scale with the structure, depending on what aspects of valve function require modelling. Thus far, we have pursued a three-pronged approach to modeling soft biological tissues, (i) Firstly, we have developed a new, more robust method for estimating viscoelastic material parameters from real-life experiments that may suffer from testing machine artifacts, such as overshoot during ramp-and-hold. The techniques involves the direct fitting of a constitutive function to the point-wise experimental data, and makes use of global optimization methods. (ii) We have advanced an existing high-fidelity micromechanical technique for the response of multi-phase materials with arbitrary periodic microstructures making use of the Generalized Method of Cells. This model can now handle material non-linearities and large strains, and is expected to provide insight into the fibril and macromolecular-level behavior of soft connective tissues, (iii) We have also developed a fully 3D theory to model the large deformations of viscoelastic solids and implemented it in a computational platform making use of the commercial code ABAQUS. This theory represents the viscoelastic behavior of soft tissues as a multi-mechanism viscoelastic solid. We thus have a collection of computational tools with which we can simulate the time-dependent viscoelastic response of different types of soft tissues at both the micro and macro-scale levels.

author list (cited authors)

  • Doehring, T., Einstein, D., Freed, A., Pindera, M. J., Saleeb, A., & Vesely, I.

publication date

  • December 2004