Mechanical Engineering Seminar
Friday, November 10, 2017
3:20 p.m., 3405 Engineering Building
Refreshments served at 3:00 p.m.
Multi-resolution ModelS OF the Mitral Heart Valve From mechanobiology to surgical repair
Michael S. Sacks, Ph.D.
W. A. “Tex” Moncrief, Jr. Simulation-Based Engineering Science Chair I
Director, Center for Cardiovascular Simulation
Institute for Computational Engineering and Sciences
Department of Biomedical Engineering
The University of Texas at Austin
An essential element of the heart function, the mitral valve (MV) ensures proper directional blood flow between the left heart chambers. Over the past two decades, computational simulations have made marked advancements towards providing powerful predictive tools to better understand valvular function and improve treatments for MV disease. However, challenges remain in the development of robust means for the quantification and representation of MV leaflet geometry. In this study, we present a novel modeling pipeline to quantitatively characterize and represent MV leaflet surface geometry. Our methodology utilized a two-part additive decomposition of the MV geometric features to decouple the macro-level general leaflet shape descriptors from the leaflet fine-scale features. First, the general shapes of five ovine MV leaflets were modeled using superquadric surfaces. Second, the finer-scale geometric details were captured, quantified, and reconstructed via a 2D Fourier analysis with an additional sparsity constraint. This spectral approach allowed us to easily control the level of geometric details in the reconstructed geometry. The results revealed that our methodology provided a robust and accurate approach to develop MV-specific models with an adjustable level of spatial resolution and geometric detail. Such fully customizable models provide the necessary means to perform computational simulations of the MV in a range of geometric detail, allowing identification of the complexity required to achieve predictive MV simulations to a desired accuracy level. We then extend these approaches to develop novel in-vivo methods for patient specific model development and incorporate novel information on MV cell-ECM coupling.
BIO:Professor Michael Sacks
Research: Cardiovascular biomechanics; computational simulation of the behavior of the cardiovascular system; advanced constitutive models, biomechanical interactions of cell, tissue, and organ in native and engineered heart valves and myocardium.
Professor Michael Sacks is the W. A. “Tex” Moncrief, Jr. Simulation-Based Engineering Science Chair and a world authority on cardiovascular biomechanics. His research focuses on modeling and simulation on the mechanical behavior and function of the heart and native and replacement heart valves He is also active in the biomechanics of engineered tissues, and in understanding the in-vitro and in-vivo remodeling processes from a functional biomechanical perspective. Dr. Sacks is currently director of the ICES Center for Cardiovascular Simulation and Professor of Biomedical Engineering. His research includes multi-scale studies of cell/tissue/organ mechanical interactions in heart valves and is particularly interested in determining the local stress environment for heart valve interstitial cells. Recent research has included developing novel multi-scale models of the mitral and bioprosthetic heart valves, as well as ventricular myocardium that allow for the separation of the individual contributions of the myocyte and connective tissue networks. His work is built on the structure-mechanical properties of native and engineered cardiovascular soft tissues, including scaffolds and multi-scale tissue-continuum cell models.
Fellow, American Society of Mechanical Engineers
Fellow (Inaugural), Biomedical Engineering Society
Fellow, American Institute for Medical and Biological Engineering
Van C. Mow Medal, American Society for Mechanical Engineers Bioengineering Division
Chancellor’s Distinguished Research Award, University of Pittsburgh
Former Editor of the Journal of Biomechanical Engineering
Ph.D., Biomedical Engineering,
University of Texas Southwestern Medical Center at Dallas
M.S., Engineering Mechanics, Michigan State University
B.S. Engineering Mechanics, Michigan State University