COMPUTATIONAL METHODS IN CARDIAC FLUID DYNAMICS

该项目的主要目标是开发一个三- 三维心脏模拟器：心脏的计算机模型，其 阀门和附近的大血管。 心脏模拟器将 使一种新的心脏研究模式成为可能， 实验中，研究人员完全控制 每个单独的实验变量和完整的访问所有 实验数据作为输出（在 模拟测量和模拟实验）。 为了测试心脏模拟器，同时 阐明诊断心脏成像的某些方面， 该项目包括计划模拟彩色多普勒血流成像， 超声心动图、造影剂血管造影、核医学（门控 血池）成像以及可能的磁共振成像。 到 模拟图像与相应的 临床图像，这将提供支持的有效性， 模型 此外，鉴于这种协议，可以使用已知的 在模拟的情况下，以提高效用的基本情况 诊断技术。 拟议的心脏模拟器的应用计划在三个 主要领域：（1）人工心脏瓣膜设计，（2） 影响机械功能的疾病的计算机模型 心脏或其瓣膜，以及（3）正常生理学研究， 功能解剖学 在人工瓣膜设计中， 计划进行的研究中，心脏模拟器将用于 优化阀门在压降方面的性能， 每搏输出量和血栓形成。 疾病的计算机模型 过程将包括瓣膜病理学，例如狭窄和 返流，涉及瓣膜的特定综合征， 二尖瓣脱垂综合征与特发性肥厚性二尖瓣狭窄 主动脉瓣下狭窄，以及室壁运动异常的情况 例如心室肥大。 在功能解剖学领域 和生理学，研究计划阐明正常的 心脏的功能。 这些研究将基于系统的 心脏参数相对于其正常值的变化， 观察对心功能的影响。 这项工作应该揭示 “设计”原则，这可能是有用的实际设计 人造心脏 另一项计划中的生理学研究 与心脏的急性和慢性适应有关， 锻炼的 除了其内在的兴趣，这项研究还将 使我们有可能在运动中测试人工瓣膜 条件 上述工作都与 成人的心 此外，该项目还涉及一系列研究， 与心脏发育和小儿心脏病学有关。 这些 包括心脏流动模式的计算机实验， 不同的发展阶段，模拟的变化， 心脏在出生时就发生了，计算机模型的发展 先天性心脏病

The principal goal of this project is to develop a three- dimensional cardiac simulator: a computer model of the heart, its valves, and the nearby great vessels. The cardiac simulator will make possible a new mode of cardiac investigation, the computer experiment, in which the investigator has complete control over each individual experimental variable and complete access to all experimental data as output (without any interference between the simulated measurement and the simulated experiment). In order to test the cardiac simulator and simultaneously to elucidate certain aspects of diagnostic cardiac imaging, the project includes plans to simulate color-Doppler flow imaging, echocardiography, contrast angiography, nuclear medicine (gated blood-pool) imaging, and possibly magnetic resonance imaging. To the extent that the simulated images agree with the corresponding clinical images, this will provide support for the validity of the model. Given such agreement, moreover, one can use the known underlying situation in the simulated case to enhance the utility of the diagnostic technique. Applications of the proposed cardiac simulator are planned in three principal areas: (1) design of prosthetic cardiac valves, (2) computer models of diseases affecting mechanical function of the heart or its valves, and (3) studies on normal physiology and functional anatomy. In prosthetic valve design,, parametric studies are planned in which the cardiac simulator will be used to optimize valve performance with respect to pressure drop, net stroke volume, and thrombogenesis. Computer models of disease processes will include valve pathology such as stenosis and regurgitation, specific syndromes involving the valves such as Mitral Valve Prolapse Syndrome and idiopathic Hypertrophic Subaortic Stenosis, and conditions in which wall motion abnormal such as ventricular aneurism. In the area of functional anatomy and physiology, studies are planned to elucidate the normal function of the heart. Such studies will be based on systematic variation of cardiac parameters about their normal values to observe the effect on cardiac function. This work should reveal "design" principles which may be useful in the actual design of artificial hearts. Another planned study in the area of physiology is concerned with the acute and chronic adaptation of the heart to exercise. Aside from its intrinsic interest, this study will also make it possible for us to test prosthetic valves under exercise conditions. The work described above is all concerned with the adult heart. In addition, the project involves a series of studies related to cardiac development and pediatric cardiology. These include computer experiments on the flow pattern of the heart at different stages of development, simulation of the changes in the heart occurring at birth, and the development of computer models of congenital heart disease.