Development of magnetically suspended centrifugal pump (MSCP) and operation system

为了克服传统离心泵的轴系问题，我们开发了一种磁悬浮离心泵(MSCP)，它是一种无轴承无密封离心泵。叶轮在泵内的磁力作用下自由而中心地悬浮。进行溶血试验，并与生物泵进行比较。MSCP的溶血指数和血小板破坏指数明显低于MSCP。动物实验旨在评价MSCP的抗血栓形成和耐用性。短期动物研究表明，在泵的叶轮上进行几种涂层方法的研究表明，硅涂层效果最好，连续泵送24小时后表面无血栓。对5只体重40-50公斤的绵羊进行长期动物研究。左心旁路的建立是通过一个进入左心房的回撤插管和一个进入降主动脉的回流插管来建立的。仅在插管时给予肝素抗凝，随后口服华法林，使凝血酶原时间延长1.5~2.0倍。五只羊存活了两周多，其中最长的存活了46天。泵送过程中获得的泵流量为3.0~5.0 L/分钟。游离血红蛋白浓度<20 mg/dl，其他生化指标均在正常范围。终止原因为导管内血栓形成2例，全身感染1例，胃肠功能障碍1例，泵内血栓1例，为存活时间最长的一例。这些结果表明，MSCP至少可以维持一个月以上，并有望应用于长期循环辅助装置，这是抢救深度心力衰竭患者的必备条件。

To overcome problems derived from the shaft within conventional centrifugal pump, we have developed a magnetically suspended centrifugal pump (MSCP) , which operates as a bearingless sealless centrifugal pump. The impeller is suspended freely and centrally by magnetic force within the pump. Hemolysis tests were performed in comparison with the Biopump. Index of hemolysis and destruction of platelets were significantly lower in the MSCP.Animal studies were designed to evaluate antithrombogenecity and durability of the MSCP.Short-term animal studies in which several coating methods on the impeller of the pump were investigated showed that silicon coating was best with results of no thrombus on the surface after continuous pumping for 24 hours. Long-term animal studies were performed using 5 sheep weighing 40 - 50 kg. The left heart by pass was established with a withdrawal cannula into the left atrium and a return cannula into the descending aorta. Heparin was given for anticoagulation only at cannulation, and Warfarin was orally administrated subsequently to keep the prothrombin time 1.5 to 2.0 folds. Five sheep survived more than two weeks with 46 days of the longest survival. The pump flow rate obtained during the pumping was 3.0 to 5.0 l/min. The free hemoglobin concentration was less than 20 mg/dl, and other parameters relating biochemistry were within normal ranges. The cause of termination was thrombus formation in the cannula in two, systemic infection in one, gastrointestinal disturbance in one, and thrombus inside the pump in one sheep, that was the longest survival. These results suggest that the MSCP could be durable for at least more than a month, and is promising for application of long-term circulatory assist device, whch is mandatory to rescue patients with the profound heart failure.