A computational framework for atherosclerotic plaque growth simulations

动脉粥样硬化斑块生长模拟的计算框架

• 批准号: 1318641
• 负责人: Benjamin Seibold
• 金额: $ 8.63万
• 依托单位: Temple University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1318641&HistoricalAwards=false
• 关键词: computational; framework; atherosclerotic; plaque; growth

The investigators develop a computational framework for the growth of atherosclerotic plaques in large arteries. Specific emphasis is placed on the nonlinear constitutive models for the arterial wall, including residual stresses, and on the bridging of the highly separated time scales that govern this process. This study focuses on the incompressible Navier-Stokes equations that describe the blood flow, coupled with nonlinear elasticity equations that govern the response of the diseased arterial walls. The actual plaque growth process exhibits a large separation of time scales between the growth of the plaque, which takes place over a course of years, and the heart rate, which is in the order of seconds. The investigators develop a methodology to couple a growth model with the fluid-structure interaction problem in a way that the fundamental challenges incurred by the separation of time scales are resolved. In addition, the computational framework allows for the incorporation of variable behavioral factors, such as physical activity and cholesterol concentration in the blood.While it is known that the rupturing of an atherosclerotic plaque can cause a heart attack, the actual growth process of plaques in arteries is far from well understood. In this project, a computational framework is developed that bridges the highly separated time scales between the plaque growth and the heart rate, and that allows for the incorporation of accurate models for the elastic arterial walls. This new framework can yield fundamental insights into the long-term causes of atherosclerosis, and the dependence of the disease on behavioral factors such as physical activity, cholesterol intake, and tobacco use. In addition, the methodologies developed in this project can find applications in the modeling of damage in elastic materials, other diseases that develop over a large time span such as abdominal aortic aneurysms and intimal hyperplasia, and biological phenomena such as the growth and transport of algae in channel flows and the growth of biofilms. This project involves a collaboration with engineers who measure residual stresses in arteries experimentally.

研究人员开发了一个计算框架，用于大动脉粥样硬化斑块的生长。特别强调了动脉壁的非线性本构模型，包括残余应力，以及控制这一过程的高度分离的时间尺度的桥接。本研究的重点是描述血流的不可压缩Navier-Stokes方程，以及控制病变动脉壁反应的非线性弹性方程。实际的斑块生长过程在斑块生长的时间尺度上有很大的差异，斑块的生长是在几年的时间里发生的，而心率则是在几秒钟的时间里。研究人员开发了一种方法，将增长模型与流固相互作用问题相结合，从而解决了时间尺度分离所带来的基本挑战。此外，计算框架允许将可变的行为因素结合起来，例如身体活动和血液中的胆固醇浓度。虽然我们知道动脉粥样硬化斑块的破裂会导致心脏病发作，但动脉中斑块的实际生长过程还远未被充分了解。在这个项目中，开发了一个计算框架，将斑块生长和心率之间高度分离的时间尺度连接起来，并允许将弹性动脉壁的精确模型结合起来。这个新的框架可以对动脉粥样硬化的长期原因以及疾病对行为因素（如体育活动、胆固醇摄入和烟草使用）的依赖产生根本性的见解。此外，本项目开发的方法可以应用于弹性材料损伤的建模，其他长时间发展的疾病，如腹主动脉瘤和内膜增生，以及生物现象，如藻类在河道流动中的生长和运输以及生物膜的生长。这个项目涉及与工程师合作，他们通过实验测量动脉的残余应力。