瓣后血流湍流剪应力在体无创测量技术

本文提出并实现了基于彩色超声多普勒速度图像分析的瓣后血流湍流剪应力的在体无创测量的数值方法及软件。首先通过图像处理和图像分析得到待测位点至少5个心动周期的速度曲线，然后在每个周期获取该位点N(N≥5)个时刻的瞬时速度信息，由此计算该位点的速度扰动并进一步计算法向雷诺应力和湍流剪应力。软件包括图像捕获、图像预处理、交互式速度获取以及湍流剪应力计算等功能，并使用了多媒体数据库对数据和图像进行管理。实际应用表明，该方法和软件是一种方便可行的在体无创测量瓣后血流湍流剪应力的手段，可为一些瓣膜疾病的诊断和人工心瓣的性能评估提供有效的血液动力学依据。

A NEW NON-INVASIVE TECHNOLOGY TO EVALUATE THE TURBULENT SHEAR STRESS IMMEDIATELY DOWNSTREAM THE HEART VALVE

A new non invasive procedure is presented to evaluate the turbulent shear stress immediately downstream the heart valve and a software based on this is developed. By using the B spline method, velocity curves are fitted to the velocity profiles digitalized from color Doppler ultrasound flow images, and then transient velocity (more than 5 for each curves) determined automatically to calculate velocity disturbance; the Reynolds normal stress, the turbulent shear stress can be obtained from velocity disturbance. The software developed has functions of image capturing, image processing, velocity information investigating and TSS calculating and so on. All the data and images are stored and managed by a specially designed database. The clinical practices of this software indicate that it is an effective and convenient tool for the evaluation of artificial heart valve.