PhD Proposal Presentation

Date: Friday November 14th, 2014

Time: 3:00pm

Location: TEP 104

Thesis committee members:

Advisor: Wei Sun, Ph.D. (BME)
John Elefteriades, M.D. (Yale)
Ajit Yoganathan, Ph.D. (BME)
Gang Bao, Ph.D. (ME)
Muralidhar Padala, Ph.D. (Emory)

Title:

Modeling and simulation of time-dependent inelastic soft tissue behavior.

Abstract:

Soft tissues undergo irreversible microstructural changes over time including elastin degradation and collagen fiber un-crimping, which are realized on the tissue level by dilation and reduced compliance. These changes can be brought on by mechanical loading and the natural aging process, and accelerated by disease.  However, the roles of mechanical and environmental factors on the progression of permanent tissue property changes are not well understood.  Most of the biomechanics work on soft tissues reported in the literature thus far, whether experimental, theoretical, or computational, is confined to static, instantaneous tissue property characterization.  As such, only the recoverable or elastic behavior of tissue is considered, although from a thermodynamics stand point, permanent changes in tissue structure and material properties represent dissipative, inelastic effects. 

The objective of this study is to develop a theoretical and computational framework to describe the inelastic behavior of soft tissues such that the effects of mechanical fatigue damage and aging in soft tissues can be accurately modeled.  A theoretical framework based on thermoelastic theory with internal variables will be developed to describe the irreversible accumulation of damage and permanent set in soft tissues over time.  The theoretical framework will then be implemented in finite element to investigate leaflet fatigue damage in bioprosthetic heart valves and age-related changes in the ascending aorta.  The results from these studies may offer scientific rationale for the design of durable tissue-based devices and improved diagnostic methods.