Tarbell J M, Gunshinan J P, Geselowitz D B, Rosenberg G, Shung K K, Pierce W S
J Biomech Eng. 1986 Aug;108(3):232-8. doi: 10.1115/1.3138608.
In this study we have employed a single channel, pulsed ultrasonic Doppler velocimeter to measure instantaneous velocity distributions within the pumping chamber of a ventricular assist device. Instantaneous velocities have been decomposed into periodic mean and turbulent fluctuating components from which estimates of Reynolds stresses within the chamber and mean shear stresses along the wall of the chamber have been obtained. A review of the complete data set indicates a maximum value of the mean wall shear stress of 25 dynes/cm2 and a maximum Reynolds stress of 212 dynes/cm2. These values are lower than those measured distal to aortic valve prostheses in vitro and are well below levels known to damage blood components. Core flow patterns, wall washing patterns and flow stagnation points are also revealed.
在本研究中，我们使用了单通道脉冲超声多普勒测速仪来测量心室辅助装置泵腔内的瞬时速度分布。瞬时速度已被分解为周期性平均分量和湍流脉动分量，据此获得了腔内雷诺应力的估计值以及沿腔壁的平均剪应力。对整个数据集的回顾表明，平均壁面剪应力的最大值为25达因/平方厘米，最大雷诺应力为212达因/平方厘米。这些值低于体外主动脉瓣假体远端测得的值，且远低于已知会损害血液成分的水平。同时还揭示了核心流型、壁面冲刷模式和流动停滞点。
