Graf T, Fischer H, Reul H, Rau G
Helmholtz-Institute for Biomedical Engineering, Aachen, Germany.
Int J Artif Organs. 1991 Mar;14(3):169-74.
Just like technical check valves, the function of mechanical heart valve prostheses may presumably also lead to cavitation effects during valve closure. Due to the waterhammer effect, cavitation may primarily occur in the mitral position leading to high mechanical loading of the valve itself and of corpuscular blood elements. Ten different types of commercial mechanical heart valves were investigated in the mitral position of a pulsatile mock loop, to detect cavitation thresholds under physiologically similar conditions by cinematographic techniques. Almost all these valve prostheses show cavitation up to a ventricular pressure gradient of 5000 mmHg/s. The threshold depends on valve type and size and is sometimes within the physiological range below 2000 mmHg/s. Visible cavitation bubbles with a diameter of up to 1.8 mm and a collapse time of less than 0.1 ms suggest that vapour cavitation may play an important role for material and blood damage in mechanical heart valve prostheses.
与技术止回阀一样，机械心脏瓣膜假体的功能在瓣膜关闭过程中可能也会导致空化效应。由于水锤效应，空化可能主要发生在二尖瓣位置，导致瓣膜本身和血细胞承受高机械负荷。在脉动模拟循环的二尖瓣位置对十种不同类型的商用机械心脏瓣膜进行了研究，以通过电影摄影技术在生理相似条件下检测空化阈值。几乎所有这些瓣膜假体在心室压力梯度高达5000 mmHg/s时都会出现空化现象。该阈值取决于瓣膜类型和尺寸，有时在低于2000 mmHg/s的生理范围内。直径达1.8毫米且崩溃时间小于0.1毫秒的可见空化气泡表明，蒸汽空化可能在机械心脏瓣膜假体的材料和血液损伤中起重要作用。
