通过人工瓣膜的血液流动是造成血栓的重要原因之一。用一个比例为10：1的放大模型对流经人工瓣膜的血流进行模拟，并采用流体可视性方法来观察血液流动和捕获其中的可见颗粒，通过数字图象处理和匹配，求得每个点的位移量和速度，从而了能准确描述该瞬间的矢量图，实现了对流体的定量描述，用该方法可以从血流动力学的角度，对人工瓣膜造成血凝的原因进行分析，并发现了有价值的现象。

Every year many heart patients use man-made valves which can be seriously imperiled by thrombi. The folw of the bloodstream passing through a man-made valve is one of the most important causes that bring about thrombi. The bloodstream is simulated with the help of a 10: 1 model and observed through a fluid visualization method. The dynamic process is videotaped by a videocamera. Then man can get the velocity and displacement of each small area by means of digital image processing and matching.The fluid arrow picture, that accurately describes the bloodstream in every twinkling, is obtained thereby.The quantitative description of the bloodstream is realized. With this method man can analyse the causes of thrombi, that the structure of a man-made valve leads to, and find valuable phenomena from it.