搏动辅助血泵的设计构思与实践——从旋涡泵到罗叶泵

The Design Conception and Realization of Pulsatile Ventricular Assist Devices--From Spiral-Vortex Pump to Luo-Ye Pump

目的 由于国际市场供应的各种血泵价格过于昂贵 ,为降低其成本而不降低其质量 ,我们设计制作了旋涡泵和罗叶泵 ,以保持良好的血液流态 ,减少栓塞和溶血等并发症的发生率。 方法 为使血液在泵动周期中始终保持连续的流线和旋涡流态以充分冲洗泵体四周 ,同时避免湍流、再循环和潴流 ,旋涡泵设计为出入血口位于不同的平面上 ,并对泵血功能进行了测定。在血液流态、溶血试验等方面与通用血泵在模拟循环台中进行了比较。罗叶泵遵循相同的原理 ,泵体为拱顶形 ,其顶部有一锥形下凹伸入泵体内部 ,出入血管道相互交叉。由于泵体拱顶不对称 ,出血口高于入血口 ,在收缩期时血流盘旋上升 ,出血口处阻力小于入血口 ,排血更为迅速和彻底。 结果 旋涡泵在血液流态和溶血试验中与通用血泵比较 ,前者均优于后者。旋涡泵在 13次的绵羊实验中 ,最后 4只未经抗凝处理的绵羊 ,于平稳转流 14天后处死(其中 1条 2 1天 ) ,尸体解剖泵内、双肾内均无栓塞。罗叶泵已于 1999年应用于临床 ,成功抢救了 1例危重患者。结论 辅助循环血泵的设计 ,其连续的流线流态、避免湍流。

Objective The purpose of developing these two pumps is to reduce its cost while the function of an assist device is maintained at a level comparable to the very expensive conventional ones on the market. The design emphasis has been on improving blood flow pattern in order to lower the thrombogenicity. Methods The inlet and outlet ports of Spiral Vortex pump,in contrast to the conventional copolar pump, are designed to locate at different planes of the pump. As a result, a continuous streamline of blood flow is produced with a spontaneous formation of vortex to washout the entire peripheral portion of the pump thoroughly in order to avoid turbulence, recirculation and stagnation.A performance curve of this pump is constructed and a comparative study between this pump and a conventional copolar pump is conducted on the mock circulation loop. The Luo Ye pump is a derivative of the Spiral Vortex pump. The inlet and outlet conduits are arranged in a crisscross fashion. The dome like asymmetrical housing with a conical shaped downward convex portion at its center ,together with crisscross conduits, would facilitate more complete evacuation of the pump. Results The results of the comparative study clearly denoted the superiority of the Spiral Vortex pump over the conventional one in terms of flow pattern and hemolysis test. Thirteen sheep experiments were performed and the last 4 sheep after repeated exhaustive improvements of the pump, survived 14 days of uneventful bypass (one survived 21 days) without routine postoperative anticoagulants.They were terminated and autopsy revealed neither clots found in the pump nor infarcts in both kidneys. As for the Luo Ye pump, both in vitro and in vivo experiments proved its effectiveness as an assist device and was successfully applied clinically in 1999. Conclusion Continuous streamline flow pattern without turbulence, recirculation and stagnation stand first in design criteria of a quality assist pump if its antithrombogenic property is to be expected for successful clinical application