CARDIOVASCULAR FLOW DYNAMICS--IN VIVO STUDIES

本年度在这一项目上的努力继续研究了 频谱和二维彩色心内血流动力学 多普勒超声定量病理生理血流动力学 异常基于流体动力学原理（射流通量理论， 动量连续性保持，中心线加速/减速， 近端流会聚和湍流/粘性相互作用），时间 并且低事件的空间定量是可能的。 数字数据 采集和分析允许0.3 mm的空间分辨率， 5毫秒的时间分辨率。 定量技术已经 适用于：1）二尖瓣返流，2）主动脉瓣返流和3） 主动脉瓣狭窄和4）人工瓣膜狭窄病变。 三 主要研究领域有：1）近端血流会聚 和加速度分布，2）湍流/粘性相互作用和3） 扩张和狭窄瓣口面积的动态变化。 此类研究 探索基本的物理原理，检查方法， 验证技术，目的是展示适用性， 无创多普勒血流成像的临床应用 相关的量化信息。

The current year's efforts on this project have continued studies of intracardiac flow dynamics with spectral and two-dimensional color Doppler ultrasound for quantifying pathophysiologic hemodynamic abnormalities. Based upon hydrodynamic principles (jet flux theory, momentum continuity preservation, centerline acceleration/.deceleration, proximal flow convergence and turbulent/viscous interactions), temporal and spatial quantitation of low events is possible. Digital data acquisition and analysis permits spatial resolutions of 0.3 mm with temporal resolutions of 5 msec. Quantitative techniques have been applied to : 1) mitral regurgitation, 2) aortic regurgitation and 3) aortic stenosis and 4) stenotic lesions in prosthetic valves. Three major areas have been under investigation: 1) proximal flow convergence and acceleration profiles, 2) turbulent/viscous interactions and 3) dynamic changes in regurgitant and stenotic orifice areas. Such studies explore fundamental physical principles, examining methodologies and validating techniques with the goals of demonstrating applicability and utility of non invasive Doppler flow imaging to obtain clinically relevant quantitative information.