This project will advance mathematical methods and computational software for simulating the dynamics of prosthetic heart valves. In the United States, heart valve diseases affect approximately 8.5% of the population aged 65 to 74 years, and approximately 13.3% of those aged 75 years or older. Treatment for severe aortic valve disease is generally to replace the heart valve with a mechanical or bioprosthetic valve, and approximately 70,000 aortic valve replacements are performed in the U.S. each year. Bioprosthetic heart valves (BHVs) degrade over time, however, and these devices have a typical durable lifetime of only 10-15 years. To date, there have been relatively few studies on modeling BHV fatigue, and there are no predictive models of BHV failure. The methods created in this project can yield advanced fluid-structure interaction (FSI) models of heart valve function as well as the first FSI modeling tools for simulating BHV valve failure. By advancing broadly applicable FSI modeling technologies and their specific application to heart valve dynamics, the project aligns with NFS's mission of promoting the progress of science and advancing national health.
This project will integrate higher-order immersed boundary (IB) methods, peridynamics, and turbulence modeling to predict prosthetic heart valve function and dysfunction (fatigue and failure). The project will advance cardiovascular FSI simulation accuracy by developing and analyzing two classes of sharp-interface immersed boundary (IB) methods capable of using experimentally constrained elasticity models with complex, three-dimensional geometries and integrating large-eddy simulation (LES) turbulence models with these new FSI methods. This project also aims to develop new FSI methods for simulating tissue failure by integrating IB methods with peridynamics, which is a nonlocal formulation of solid mechanics that is well suited for modeling structural failure. These models will be validated using experimental data obtained in ongoing studies at the FDA Heart Valve Lab. These methods will be implemented within the open-source IBAMR software, which is used by many independent research groups in a broad range of fields. This project also integrates research aims with an educational plan leverages UNC's outstanding high-performance computing environment, experimental facilities available to UNC's applied math group, and UNC's major new makerspace initiative, BeAM (Be a Maker). Finally, research and educational products of this project will be incorporated into ongoing activities at UNC's main science outreach unit, the Morehead Planetarium & Science Center.
