Computational Modeling of Mechanical Heart Valves

描述(申请人提供)：人工心脏瓣膜(PHV)已经使用了四年以上 几十年来更换患病的心脏瓣膜。然而，目前的设计远远不是理想的和 严重的并发症，如溶血、血小板破坏和血栓栓塞症，通常在 他们的植入，需要积极的终身抗凝治疗，这反过来会带来严重的 副作用。然而，改进当前的PHV设计需要高度准确的流量量化-a 这项任务直到最近才能完成，因为混合动力汽车的复杂和错综复杂的几何结构与 缺乏适当的计算方法来处理PHV流动的复杂性。小说 流固耦合CFD工具已在当前成功开发和验证 格兰特。随着大量的实验研究，这种数值工具已经产生了有史以来第一个深度 了解生理条件下和血流动力学相关尺度下PHV流动的复杂物理现象。拟议的竞争性更新迈出了下一步， 实现用于改进瓣膜假体设计的计算框架的开发 根据患者的具体情况。目前的磁共振成像(MRI)技术使人们有可能 以足够高的分辨率获得完整的3D运动几何图形，以指定主动脉和室壁 运动作为数值模式的边界条件。通过结合高分辨率CFD技术 随着核磁共振技术的最新进步，一种强大的、临床上有用的血液动力学/液体 可以开发动态分析工具，以造福于PHV接受者。 推动这种竞争性更新的总体假设是：高分辨率、基于成像的计算 流体动力学(CFD)建模可用于开发可行的特定于患者的血流动力学工具 其中心脏装置(不仅限于心脏瓣膜假体)可以在患者之前进行评估 治疗。这一假设将在以下四个目标中加以阐述： 目标1：开发用于左心室/主动脉构型的CFD工具 目的2：体外实验验证有运动的左心室/主动脉模型的有效性 边界 目的3：发展图像处理方法以重建解剖上精确的运动脑室 以及大动脉的几何形状 目标4：完成患者模拟和分析的计算工具的初步应用 该项目的实施将导致心脏瓣膜流动分析领域的重大进步 流体机械改进型心脏装置的开发。公共卫生相关性： 目前人工心脏瓣膜的设计远不理想，存在严重的并发症风险，需要患者接受积极的终生抗凝治疗，这反过来又会带来 额外的风险。在这场竞争的更新中，原始的计算技术产生了 GRANT被进一步开发，能够模拟患者特定解剖中的流动。这将是 通过使用磁共振成像获得患者的实际几何形状，并将这些信息与当前计算流体的更复杂和改进的版本相结合来实现 动力学软件。

DESCRIPTION (provided by applicant): Prosthetic heart valves (PHV) have been in use for over four decades to replace diseased heart valves. However, present-day designs are far from ideal and significant complications such as hemolysis, plateletdestruction, and thromboembolism often arise after their implantation, requiring aggressive life long anticoagulation therapy which in turn carries serious side effects. Improving current PHV designs, however, needs highly accurate flow quantification - a task not achievable until recently due to the complex and intricate geometries of PHVs combined with the lack of an appropriate computational methodology to tackle the complexities of PHV flows. Novel fluid-structure interaction CFD tools have been successfully developed and validated in the current grant. Along with numerous experimental studies, this numerical tool has yielded the first ever in depth understanding of the complex physics of PHV flows under physiological conditions and at hemodynamically relevant scales. The proposed competing renewal takes the next step towards achieving the development of a computational framework for improving valve prosthesis designs on a patient-specific basis. Current Magnetic Resonance Imaging (MRI) technology makes it possible to obtain full 3D moving geometries at resolution sufficiently high to prescribe aorta and ventricular wall motions as boundary conditions for the numerical model. By coupling high resolution CFD techniques with the latest advancements in MRI technology, a powerful and clinically useful hemodynamic/fluid dynamic analysis tool could be developed for the benefit of PHV recipients. The overall hypothesis driving this competing renewal is: High resolution, imaging-based Computational Fluid Dynamics (CFD) modeling can be used to develop viable patient-specific hemodynamic tools where cardiac devices (not only limited to heart valve prostheses) may be evaluated prior to patient treatment. This hypothesis will be addressed in the following four aims: Aim 1: Development of CFD tools for left ventricle/aorta configuration Aim 2: In vitro experiments for validation in a phantom left ventricle/aorta configuration with moving boundaries Aim 3: Develop image processing methods for reconstruction of anatomically accurate moving ventricle and aorta geometries Aim 4: Preliminary application of the computational tools for patient simulation and analysis Completion of this project will lead to a significant advancement in the field of heart valve flow analysis and the development of fluid mechanically improved cardiac devices. PUBLIC HEALTH RELEVANCE: Present day designs of prosthetic heart valves are far from ideal and significant risk of complications exist requiring patients to undergo aggressive life long anti-coagulation therapy which in turn carries additional risks. In this competing renewal, the computational technology produced during the original grant is further developed to be able to simulate flows in patient specific anatomies. This will be achieved by obtaining actual geometries of patients using magnetic resonance imaging and coupling this information with a more sophisticated and improved version of the current computational fluid dynamics software.