Fluid Mechanics of the Mitral Valve: In Vitro Studies

描述(申请人提供)：为期5年的体外研究 天然二尖瓣(MV)的力学被提出以延续我们以前的 检查正常的阀门机械结构，以及在以下情况下发生的变化 疾病或在瓣膜化学固定之后。正常体液和小叶 将研究动力学，以检查环形平面性的影响，以及 环状尺寸对整体阀门功能的影响。流体和液体中的相对变化 将通过直接测量二尖瓣血流来评估瓣叶机制， 以及通过高速视频成像，测力， 和多普勒超声。血流动力学和小叶动力学将被绑定到 通过石墨标记物追踪技术评估小叶组织力学 叶片在动态条件下的应变场和挠度。这项研究将 还通过检查一系列环状孔口区域来解决疾病状态 以及平面性和乳头肌(PM)位置改变。信息 关于瓣膜相对于环形平面性的函数将有助于 外科医生在进行瓣膜修复手术时的关键决策，如 如环状成形术和脊索置换术。进一步检验化学品 固定技术也被用来研究静态固定过程。这 将更好地理解结构修改是如何发生的 在化学固定过程中会影响瓣膜的动态。它的意义和 拟议的研究的临床意义是改善我们的基础 对二尖瓣功能的认识二尖瓣流体力学及传单 动力学)在正常解剖条件下和病理变化下对 二尖瓣装置，特别是由于慢性和急性缺血的影响 二尖瓣返流。目的是增进我们对阀门的了解 生理条件下体外MV控制试验的动力学研究 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 在环形平面度、尺寸和粉末冶金定位方面。这将导致改进 由内科医生诊断和治疗MV病，并提供外科医生 有关维修技术对整体阀门的影响的信息 功能性。在MV更换的情况下，调查固定过程 将通过提供以下有关阀门动态的数据来帮助它们的制造 定格。利用柔韧和僵硬的左手进行全面的体外研究 正在计划建立心室模型以及人和猪的二尖瓣。这个 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。这个 使用无法在体内使用的最先进的测量系统将 产生显著的效果。

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.