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

为了克服传统离心泵中轴产生的问题，我们开发了磁悬浮离心泵 (MSCP)，它作为无轴承无密封离心泵运行。叶轮通过泵内的磁力自由且居中地悬挂。进行溶血测试并与生物泵进行比较。 MSCP的溶血指数和血小板破坏指数显着降低。动物研究旨在评估MSCP的抗血栓形成性和耐久性。短期动物研究对泵叶轮的几种涂层方法进行了研究，结果表明硅涂层效果最好，连续泵送24小时后表面无血栓。使用 5 只体重 40 - 50 公斤的绵羊进行了长期动物研究。通过将抽出插管插入左心房并将返回插管插入降主动脉来建立左心旁路。仅在插管时给予肝素抗凝，随后口服华法林以保持凝血酶原时间1.5～2.0倍。有5只羊存活了两周多，最长的存活了46天。泵送期间获得的泵流量为3.0至5.0l/min。游离血红蛋白浓度低于20 mg/dl，其他生化相关参数均在正常范围内。因插管血栓形成2只，全身感染1只，胃肠道功能紊乱1只，泵内血栓1只，存活时间最长。这些结果表明，MSCP可以持续至少一个月以上，并且有望用于长期循环辅助装置的应用，这是抢救严重心力衰竭患者所必需的。

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.