CAREER: Numerical Methods and Computational Infrastructure for Simulating Prosthetic Heart Valve Function and Dysfunction

该项目将推进模拟人工心脏瓣膜动力学的数学方法和计算软件。在美国，65岁至74岁的人口中约有8.5%患有心脏瓣膜疾病，75岁或以上的人口中约有13.3%患有心脏瓣膜疾病。严重主动脉瓣疾病的治疗通常是用机械或生物假体瓣膜代替心脏瓣膜，在美国每年大约进行70,000例主动脉瓣置换术。然而，生物假体心脏瓣膜（bhv）会随着时间的推移而降解，这些设备的典型耐用寿命只有10-15年。迄今为止，关于BHV疲劳建模的研究相对较少，也没有BHV失效的预测模型。该项目中创建的方法可以生成心脏瓣膜功能的高级流固耦合（FSI）模型，以及用于模拟BHV阀门失效的第一个FSI建模工具。通过推进广泛适用的FSI建模技术及其在心脏瓣膜动力学中的具体应用，该项目与NFS促进科学进步和促进国民健康的使命保持一致。本项目将整合高阶浸入边界（IB）方法、周动力学和湍流建模来预测人工心脏瓣膜的功能和功能障碍（疲劳和失效）。该项目将通过开发和分析两类尖锐界面浸入边界（IB）方法来提高心血管FSI模拟的准确性，这些方法能够使用具有复杂三维几何形状的实验约束弹性模型，并将大涡模拟（LES）湍流模型与这些新的FSI方法相结合。该项目还旨在开发新的FSI方法，通过将IB方法与周动力学相结合来模拟组织破坏，这是一种非常适合模拟结构破坏的非局部固体力学公式。这些模型将使用FDA心脏瓣膜实验室正在进行的研究中获得的实验数据进行验证。这些方法将在开源的IBAMR软件中实现，该软件被许多独立研究小组在广泛的领域中使用。该项目还将研究目标与教育计划结合起来，利用北卡罗来纳大学优秀的高性能计算环境，北卡罗来纳大学应用数学小组可用的实验设施，以及北卡罗来纳大学主要的新创客空间倡议，BeAM （Be a Maker）。最后，该项目的研究和教育成果将被纳入北卡罗来纳大学主要科学推广单位莫尔黑德天文馆科学中心的持续活动中。

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.