Zapanta C M, Liszka E G, Lamson T C, Stinebring D R, Deutsch S, Geselowitz D B, Tarbell J M
Bioengineering Program, Pennsylvania State University, University Park 16802.
J Biomech Eng. 1994 Nov;116(4):460-8. doi: 10.1115/1.2895797.
A method for real-time in vitro observation of cavitation on a prosthetic heart valve has been developed. Cavitation of four blood analog fluids (distilled water, aqueous glycerin, aqueous polyacrylamide, and aqueous xanthan gum) has been documented for a Medtronic/Hall prosthetic heart valve. This method employed a Penn State Electrical Ventricular Assist Device in a mock circulatory loop that was operated in a partial filling mode associated with reduced atrial filling pressure. The observations were made on a valve that was located in the mitral position, with the cavitation occurring on the inlet side after valve closure on every cycle. Stroboscopic videography was used to document the cavity life cycle. Bubble cavitation was observed on the valve occluder face. Vortex cavitation was observed at two locations in the vicinity of the valve occluder and housing. For each fluid, cavity growth and collapse occurred in less than one millisecond, which provides strong evidence that the cavitation is vaporous rather than gaseous. The cavity duration time was found to decrease with increasing atrial pressure at constant aortic pressure and beat rate. The area of cavitation was found to decrease with increasing delay time at a constant aortic pressure, atrial pressure, and beat rate. Cavitation was found to occur in each of the fluids, with the most cavitation seen in the Newtonian fluids (distilled water and aqueous glycerin).
已开发出一种用于实时体外观察人工心脏瓣膜上的空化现象的方法。已记录了美敦力/霍尔人工心脏瓣膜在四种血液模拟液（蒸馏水、甘油水溶液、聚丙烯酰胺水溶液和黄原胶水溶液）中的空化情况。该方法在模拟循环回路中使用了宾夕法尼亚州立大学电动心室辅助装置，该回路以与降低心房充盈压相关的部分充盈模式运行。观察是在位于二尖瓣位置的瓣膜上进行的，每个周期瓣膜关闭后，空化现象发生在入口侧。频闪摄影用于记录空化的生命周期。在瓣膜封堵器表面观察到气泡空化。在瓣膜封堵器和外壳附近的两个位置观察到涡旋空化。对于每种液体，空化的生长和坍塌发生在不到一毫秒的时间内，这有力地证明了空化是蒸汽性的而非气态的。发现在恒定主动脉压力和心率下，空化持续时间随心房压力的增加而减少。发现在恒定主动脉压力、心房压力和心率下，空化面积随延迟时间的增加而减少。发现在每种液体中都会发生空化，其中在牛顿流体（蒸馏水和甘油水溶液）中观察到的空化现象最多。
