Stevenson D M, Yoganathan A P, Franch R H
Scand J Thorac Cardiovasc Surg. 1982;16(1):1-7. doi: 10.3109/14017438209100601.
Thrombus formation on the outflow face and tissue overgrowth along the sewing ring adjacent to the minor outflow region are major clinical pathologic problems observed with the Björk-Shiley tilting disc valve. In the hope of reducing these pathologic conditions the convexo-concave Björk-Shiley valve was designed. A new modification to the convexo-concave model has further improved most of the fluid dynamic characteristics of the valve. In vitro flow studies indicate an average improvement in pressure drop characteristics of about 20 to 30%. Velocity measurements made with a laser-Doppler anemometer in the immediate downstream vicinity of the modified convexo-concave valve indicate that the design changes have further reduced the size of the stagnation zone near the outflow face of disc. It was observed, however, that the regurgitation across the valve increased by about one to two percentage points.
在流出面形成血栓以及在与小流出区域相邻的缝合环处组织过度生长是Björk-Shiley倾斜盘式瓣膜所观察到的主要临床病理问题。为了减少这些病理状况，设计了凸凹型Björk-Shiley瓣膜。对凸凹型模型的一项新改进进一步改善了瓣膜的大多数流体动力学特性。体外流动研究表明，压降特性平均改善了约20%至30%。用激光多普勒风速仪在改进的凸凹型瓣膜紧邻下游处进行的速度测量表明，设计上的改变进一步减小了盘流出面附近停滞区的大小。然而，观察到瓣膜反流增加了约一到两个百分点。
