新型左心辅助装置的体外溶血试验

目的：观察研究在左心辅助情况下，不同流量，驱动压力，压缩时间比等条件下，对于血液破坏情况。方法：新鲜狗血注入肝素，达到完全肝素化(ACT时间大于450s)．在装有新型左心辅助泵的体外循环测试系统中，利用自制的动力驱动系统，分析不同压力，频率，流量下的血浆游离血红蛋白(FHb)，血浆纤维蛋白原(Fib)的变化。结果：在相同流量下，驱动压力越大FHb指标越高，Fih指标越低，在平均血压固定下，改变压缩时间比为0．25～0．45，发现在0．38有较低的FHb和较高的Fib结果，而在驱动压力，压缩时间比固定的条件下，流量越大，对血液的破坏越大。结论：在流量固定情况下，越小有效驱动压力以及保持左心辅助的压缩比为0．38对血液破坏较少，而增加流量将增大对血液的损伤。

In vitro hemolysis test of a novel left ventricular assist device

AIM: To observe the hemolysis changes in our self made left ventricular assist device in an in vitro circulation system and to investigate the effects of the flow of fluid, and the frequencies, the pressure and the systolic percentage of the device on erythrocytes. METHODS: Fresh blood samples were obtained from healthy dogs and the activated clotting time (ACT) was maintained over 450 s with heparitin. Blood samples were infused in vitro circulation system equipped with a left ventricular assist pump, and the changes of plasma free hemoglobin(FHb)and fibrinogen(Fib)with different frequency, pressure and systolic percentage were observed. RESULTS: With the same flow of fluid, the higher the pressure, the higher the level of FHb and the lower the level of Fib. With the same pressure and the range of systolic time percentage from 0.25 to 0.45, relatively lower level of FHb and higher level of Fib were observed when systolic time percentage was 0.38. With the same frequency, pressure or systolic time percentage, the higher the flow volume, the higher level of FHb and the lower level of Fib. CONCLUSION: With the same flow of fluid, the pressure is positively correlated to the severity of the erythrocyte damage. The lowest efficient pressure and the systolic time percentage of 0.38 cause the least damage to erythrocytes.