Multiscale simulations of the aortic heart valve : applications in disease and surgery

This thesis presents mathematical models describing the mechanical behavior of the human aortic heart valve over a range of length and time scales. In the human heart, the valves perform the vital function of controlling the direction of blood flow. Each valve is an intricate mechanical structure, with distinct features and functions at multiple scales. This effort first develops a framework of reference configurations that enables communication between simulations of the different length scales. Three simulations are created within that framework. At the cell scale, the interaction between a single valvular interstitial cell and its surrounding matrix is described. At the tissue scale, a model is created for the valve cusp tissue mechanical behavior, including the multilayered, nonuniform geometry and nonlinear, anisotropic material properties. At the organ scale, a dynamic, three-dimensional model with fluid-structure interaction predicts the motion of the valve, blood, and surrounding tissue. Each simulation is verified against a number of experimental measures. These three simulations together constitute a model for the dynamic, three-dimensional, multiscale mechanical behavior of the healthy human aortic heart valve throughout the cardiac cycle. The model is employed to perform multiscale investigation into the mechanisms of the disease calcific aortic stenosis in three ways. First, the model of the healthy valve is extended to describe disease progression on the decade time scale. Calcification is introduced at the tissue level and the effects on valve function are monitored at the organ level. Second, the role of mechanical deformations in the disease process is examined by comparing multiscale deformations between the normal valve case and a known disease-prone case.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• Weinberg, Eli, 1979-

Advisor dc:contributor.advisor

• Mohammad Kaazempur Mofrad and Jeffrey Borenstein.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/44797

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/44797