Mike Evans

Bachlers of Science in Mechanical Engineering, Ohio Northern University,
May, 1997

Ph.D. Candidate, Materials Science, University of Minnesota

mevans@cems.umn.edu

Bio

Research

Tissue engineering combines a wide variety of science and engineering with one common goal of designing replacements for aged or diseased tissues. One area of tissue engineering employs biopolymer matrices seeded with living cells which compact the matrix into a tissue like material, or tissue equivalent (TE). A major requirement of TEs is that they have properties similar to that of the tissues they are replacing. Mathematical modeling is useful in determining the final properties of the TE and the conditions under which they should be produced. In biopolymer TEs, the microstructure of the material is vital in the macroscopic material properties. The fibrils can be randomly oriented resulting in an isotropic material, or they can be aligned through several different processes resulting in anisotropic material properties.

A continuum approach to modeling tissue was developed by Barocas and Tranquillo. The continuum approach focuses on the macroscopic properties resulting from the underling microstructure of the material. The Anisotropic Biphasic Theory (ABT) predicts the remodeling of TEs very well up to 15% strain. 3-D adaptive finite element software has been developed by Ohsumi and Flaherty to solve the model equations. The software has both h and r adaptivity; h-adaptivity allows moving boundaries while r-adaptivity allows the mesh to refine in areas of large gradients. The adaptivity of the software gives a more efficient and accurate solution.

Our goal is to use the ABT and the 3-D adaptive finite element software to simulate the remodeling of the tissue equivilent heart valve. With the knowlage of how the vlave changes during remodeling, a better design of the heart valve can be obtained.