Yoganathan A P, Woo Y R, Sung H W
J Biomech. 1986;19(6):433-42. doi: 10.1016/0021-9290(86)90020-5.
A two dimensional laser Doppler anemometer system has been used to measure the turbulent shear fields in the immediate downstream vicinity of a variety of mechanical and bioprosthetic aortic heart valves. The measurements revealed that all the mechanical valves studied, created regions of elevated levels of turbulent shear stress during the major portion of systole. The tissue bioprostheses also created elevated levels of turbulence, but they were confined to narrow regions in the bulk of the flow field. The newer generation of bioprostheses create turbulent shear stresses which are considerably lower than those created by the older generation tissue valve designs. All the aortic valves studied (mechanical and tissue) create turbulent shear stress levels which are capable of causing sub-lethal and/or lethal damage to blood elements.
二维激光多普勒风速仪系统已被用于测量各种机械和生物主动脉心脏瓣膜紧邻下游处的湍流剪切场。测量结果显示，所有研究的机械瓣膜在收缩期的大部分时间内都会产生湍流剪切应力水平升高的区域。组织生物瓣膜也会产生湍流水平升高的区域，但它们局限于流场主体中的狭窄区域。新一代生物瓣膜产生的湍流剪切应力远低于老一代组织瓣膜设计所产生的应力。所有研究的主动脉瓣膜（机械瓣膜和组织瓣膜）产生的湍流剪切应力水平都能够对血液成分造成亚致死和/或致死性损伤。
