Compliance and Dynamic Geometry Variation in Coronory Artery Flows under In-Vivo Conditions

1235790 .心血管疾病（CVD）是世界上最大的死亡原因。大量研究表明，动脉壁力学和流体力学在心血管疾病的介导中起着重要作用。当心脏跳动时，附着在心包表面或穿透心肌壁的冠状动脉（CA）也会发生剧烈运动。这种运动在本质上是大尺度和三维的，具有局部曲率和扭转血管的变化。由于斑块形成（动脉粥样硬化）或支架放置导致的动脉壁硬度变化，这种运动对血流流体动力学的影响进一步复杂化。本研究的假设是，在CA血流中，由于心肌运动引起的大范围运动以及血管刚度的局部变化或不连续导致非生理性的血流模式和异常的壁剪切应力触发动脉粥样硬化。为了解决科学和工程上的挑战，我们将使用最先进的高分辨率计算来创建一个独特的研究框架，这将大大增加我们对这些复杂流动系统的理解。利用完全解析的流体-结构相互作用（FSI）的计算模型，计算将以前所未有的保真度处理非定常耦合流体结构与心肌运动和动脉流动特征的相互作用，这在过去一直是研究人员的挑战。研究冠状动脉在心肌运动影响下具有各向异性顺应性的柔性血管中FSI的物理机制，将有助于对生理系统中转运过程的新认识。研究资助将培养一名研究生，并为一些本科生提供研究经验。将采取若干举措，使妇女和少数民族参与研究和教育，并促进与医疗机构的研究伙伴关系。拟议的研究将有助于更好地诊断血管疾病，并将对心血管疾病的管理产生广泛的影响，有可能挽救数百万人的生命。它将为分析和改进血管植入物以及开发新的和改进的治疗方法和设备提供所需的基础。

1235790TaftiCardiovascular diseases (CVD) are the number one causes of death in the world. Extensive research has shown that arterial wall mechanics and fluid dynamics play an important role in CVD mediation. As the heart beats, the coronary arteries (CA), which are attached to the pericardial surface or penetrate the myocardial wall, also experience substantial motion. This motion is large scale and three dimensional in nature, with local changes in curvature and torsion of the vessel. The effect of this motion on the fluid dynamics of blood flow is further complicated by variations in arterial wall stiffness resulting from plaque formation (atherosclerosis) or the placement of stents. The research is driven by the hypothesis that in CA flows, the large scale motions due to the motion of the myocardium along with local variations or discontinuities of the vessel stiffness lead to non-physiological flow patterns and abnormal wall shear stresses triggering atherosclerosis. In order to tackle the scientific and engineering challenges imposed, we will use state-of-art highly-resolved computations to create a unique research framework that will significantly augment our understanding of these complex flow systems. Using computational modeling of fully resolved fluid-structure-interaction (FSI), the computations will tackle with unprecedented fidelity the unsteady coupled fluid structure interactions with applied motion of the myocardium and the arterial flow characteristics that have challenged researchers in the past. Resolving the physical mechanisms of FSI in flexible vessels with anisotropic compliance under the influence of the myocardial motion as experienced in coronary arteries will lead to new understanding of transport processes in physiological systems. The research grant will train one graduate student and provide research experience to a number of undergraduate students. A number of initiatives will be undertaken to involve women and minorities in research and education, and to foster research partnerships with medical institutions. The proposed research will contribute towards better diagnosis of vascular disease and will have broad ranging implications on the management of cardio-vascular disease with the potential of saving millions of lives. It will provide the foundation needed for analyzing and improving vascular implants as well as enable the development of new and improved treatments and devices.