Fluid Mechanics of the Mitral Valve: In Vitro Studies

描述（由申请人提供）：5年体外研究 天然二尖瓣（MV）的力学建议继续我们以前的 工作检查正常的阀门力学，并发生变化的情况下， 疾病或瓣膜化学固定后。正常的液体和小叶 动力学将被研究，以检查环形平面性的影响， 环空尺寸对整个阀门功能的影响。流体中的相对变化， 将通过直接测量二尖瓣血流来评估瓣叶力学， 以及通过高速视频成像，力测量， 和多普勒超声血流动力学和瓣叶动力学将与 通过石墨标记跟踪技术评估瓣叶组织力学 动态条件下的瓣叶应变场和挠曲。本研究将 还通过检查一系列瓣环口面积来解决疾病状态 沿着出现平面性和乳头肌（PM）位置改变。信息 关于瓣环平面性的瓣膜功能将有助于 外科医生在进行瓣膜修复手术时， 瓣环成形术和腱索置换术。进一步检查化学品 固定技术也被提出来研究静态固定过程。这 将提供更好的理解结构变化是如何发生的， 在化学固定期间影响瓣膜动力学。的意义和 临床相关性的拟议研究是为了提高我们的基本 了解二尖瓣功能、二尖瓣流体力学和瓣叶 动力学）和病理变化的情况下， 二尖瓣装置，特别是由于慢性和急性缺血性 二尖瓣返流我们的目标是提高我们对阀门的认识 通过在生理条件下进行受控体外MV测试， 先进的体外建模技术的发展。这将提供 外科医生和心脏病学家关于MV对变化的反应的科学数据 环形平面度、尺寸和PM定位。这将改善 诊断和治疗MV疾病的医生，并提供外科医生 关于修复技术对整体瓣膜影响的信息 功能.在二尖瓣置换术中，研究固定过程 将有助于他们的制造提供数据的阀门动力学以下 固定一项综合性体外研究，使用柔性和刚性左心室 心室模型和人类和猪二尖瓣。的 实验将在提供隔离的受控环境中进行 没有由竞争因素引入的伪影的特定参数。的 使用不能用于体内使用的现有技术的测量系统将 产生显著的结果。

DESCRIPTION (Provided by Applicant): A 5 year in-vitro investigation of the mechanics of the natural mitral valve (MV) is proposed to continue our previous work examining normal valve mechanics, and changes that occur in cases of disease or following valve chemical fixation. The normal fluid and leaflet dynamics will be studied to examine the effects of annular planarity, and annular size on overall valve function. The relative changes in the fluid and leaflet mechanics will be assessed by measuring the transmitral flow directly, and the valve leaflet dynamics by high-speed video imaging, force measurements, and Doppler ultrasound. The hemodynamics and leaflet dynamics will be tied to leaflet tissue mechanics through a graphite marker tracking technique to assess the leaflet strain fields and flexure under dynamic conditions. This study will also address diseased states by examining a range of annular orifice areas along with planarity and altered papillary muscle (PM) position. Information regarding valvular function with respect to annular planarity will assist surgeons in critical decisions when performing valvular repair procedures, such as ring annuloplasty and chordal replacement. Further examination of chemical fixation techniques is also proposed to study static fixation processes. This will provide a better understanding of how structural modifications that occur during chemical fixation influence valve dynamics. The significance and clinical relevance of the proposed research is to improve our fundamental understanding of mitral valve function transmitral fluid mechanics and leaflet dynamics) under normal anatomical conditions and pathological changes to the mitral apparatus, especially due to the effects of chronic and acute ischemic mitral regurgitation. The goal is to enhance our understanding of valve dynamics through controlled in vitro MV testing under physiologic conditions by development of advanced in vitro modeling techniques. This will provide surgeons and cardiologists scientific data on the response of the MV to changes in annular planarity and size and PM positioning. This will result in improved diagnosis and treatment of MV disease by physicians, and provide surgeons information about the effect that repair techniques have on overall valve functionality. In the case of MV replacements, investigating fixation processes will help in their manufacture by providing data on valve dynamics following fixation. A comprehensive in vitro study utilizing both flexible and rigid left ventricular models and human and porcine mitral valves is planned. The experiments will be performed in a controlled environment providing isolation of specific parameters without artifacts introduced by competing factors. The use of state of the art measurement systems unavailable for in vivo use will yield significant results.