Schuster P R, Wagner J W
U.S. Food and Drug Administration, Center for Devices and Radiological Health, Rockville, MD 20852.
Med Prog Technol. 1988;14(3-4):177-91.
In vitro techniques for evaluating circulation through prosthetic heart valves can yield important information concerning valve performance prior to implantation. Laser Doppler velocimetry is the most widely accepted noninvasive flow measurement technique, however, its use is somewhat limited for flow mapping applications. Holographic velocimetry is an alternative noninvasive in vitro approach for flow diagnostics. The advantage of this technique is the ability to do instantaneous full volume measurements for complete three-dimensional flow mapping at any instant in a flow cycle. Holographic velocimetry was used for the evaluation of circulation through a ball and cage valve. Results indicate that just beyond the apex of the cage very low velocity exists in the mean flow direction, while the other two components of velocity are rather large. Studies done further downstream from the valve begin to show the flow characteristics returning to the state of fully developed turbulent flow, as was previously seen upstream from the valve housing.
评估人工心脏瓣膜血流情况的体外技术能够在植入前提供有关瓣膜性能的重要信息。激光多普勒测速法是最广泛认可的非侵入性血流测量技术，然而，它在血流成像应用方面的使用存在一定局限性。全息测速法是一种用于血流诊断的替代性非侵入性体外方法。该技术的优势在于能够在血流周期的任何时刻对整个三维血流进行瞬时全容积测量以实现完整的血流成像。全息测速法被用于评估通过球笼式瓣膜的血流情况。结果表明，就在瓣膜笼顶部之外，平均血流方向上存在非常低的流速，而其他两个速度分量则相当大。在瓣膜下游进一步开展的研究开始显示血流特性恢复到充分发展的湍流状态，正如之前在瓣膜外壳上游所观察到的那样。
