三相交流超导磁流体人工血泵的初步研制

Heart failure ranked first in all cause of death due to the poor efficacy of drugs and pacemaker in recent years. Heart transplantation represents an effective means in therapy of heart failure, however, it's application is greatly limited by surgical infection, immune rejection, secondary coronary artery disease and severe lack of donor organs. Until now only two artificial hearts are used in human body, which just as a means of transition before heart transplantation. Because of many drawbacks existing in artificial heart such as thrombosis, hemolysis, short life and others, artificial heart cannot be regard as a real substitute for human heart. The drawbacks mainly come from contact between blood and mechanical devices from artificial blood pump system in which the blood circulation was driven by mechanical force generated from impeller or bursa. This study proposes a three-phase AC superconducting magnetohydrodynamics（MHD） artificial blood pumps: superconducting materials made from three-phase coil generates a rotating magnetic field; when blood flows through the magnetic field, produced current and Ampere force role promote blood flow. Due to lack of direct contact between blood and mechanical devices, this artificial blood pump system driven by electromagnetic force avoids the production of thrombosis and hemolysis. The new system is expected to overcome the shortcoming presented in existing equipment, and may play a key role in developing new artificial heart used in replacing heart transplantation.

现有的人工心脏仅有两款应用于人体，但只能作为心脏移植前的过渡手段，不能替代人体心脏长期工作，主要原因为现有的人工心脏存在血栓、溶血、寿命短等缺点。这些缺点的产生是由于其驱动系统是靠叶轮或腔囊产生的机械力推动血液流动，这不可避免血液与机械装置的接触并产生溶血及血栓。若在人工血泵研制上另辟蹊径，让动力部分与血液不直接接触，将彻底解决人工心脏的组织相容性问题。本研究提出了三相交流超导磁流体人工血泵：超导材料电阻极低，用它制成三相线圈，其能耗极低、效率高、发热少；在其中通交流电后可产生旋转磁场，使流经磁场的血液产生感生电流并受到磁场安培力的作用，以推动血液流动；这种人工血泵用电磁力驱动血液流动，没有与血液直接接触的机械构件，无血栓、溶血等组织相容性的问题；它可望彻底解决现有人工血泵存在组织相容性问题的弊端，并减少充电次数，为未来新型人工心脏替代心脏移植、并使患者长期存活成为可能。

人工心脏替换作为终末期心衰病人的一种治疗手段，现被世界各国科学家热研。而作为人工心脏核心部件的动力部分，人工血泵，其又因血泵中机械元件的使用，不可避免的会出现溶血、感染等影响患者生存率的重要并发症。我们申请所研发的新型三相超导交流磁流体人工血泵是建立在以磁力作为动力推动血液的持续流动，并且不破坏血液细胞的结构，减少以上并发症的发生。在此次体外绵羊血急性试验中，我们发现：1、血液在约为0.9T交变磁场强度时，血液可缓慢持续流动，约为2mm/s；2、在对血液细胞计数和电子透射显微镜（TEM）观察时发现，作为血液细胞中最为重要的红细胞，其细胞结构完整，无明显血液细胞的破坏；3、在血液细胞TEM检测中发现，交变磁场可能对血液细胞中的铁蛋白分布会有影响。综上所述，三相交变磁流体血泵研发可行，对血液无明显破坏作用，其在日后待微型、大功率超导交变磁体研发成功后，具有深远的临床意义。