用于左心室辅助的φ25mm主动脉瓣膜泵

Development of φ25 mm implantable aortic valvo-pump

研制出能够满足解剖和生理要求的心脏瓣膜泵.装置只有一个定子和一个转子,装置内没有轴承或其他支承物.叶轮叶片采用三元解析方法设计,可以防止滞流和紊流的产生.装置最大处的直径为24.7 mm,长12.4 mm;装置重40g,转子重11g;当转速为15 000 r/min时消耗功率为7W.血动力学测试试验表明,流经瓣膜泵的最大流量可达10 L/min,0流量时对应的输出压力为80 mmHg;当流量为4～8L/min时,瓣膜泵能增加循环流量约1 L/min,提高输出压约10 mmHg;由离心泵产生的搏动血流在经过瓣膜泵以后压力搏动值保持在40mmHg左右.以一头80kg重的猪进行首次受体动物试验,将瓣膜泵缝在主动脉进口位置,结果表明装置的植入对周围的组织和器官不会造成损害.

For better anatomic and physiological fitting, a prototype of 25 mm outer diameter implantable aortic valvo-pump (IAVP) as a left ventricular assist device (LVAD) has been developed. The device has a rotor and a stator; the rotor consists of magnets and impeller and the stator has a motor coil and outflow guide vanes. By hemodynamic tests, IAVP together with a pulsatile centrifugal pump developed by authors delivers saline in a circulatory model. Results demonstrated that this 40 gram weight micro axial pump can pass through a flow of 10 L/min and maintain a pressure head of 80 mmHg during zero flow rate. At flow rate of 4-8 L/min, the pump can increase the flow rate of centrifugal pump imitating the natural ventricle about 1 L/min, meanwhile increases the pressure head round 10 mmHg compared with the case without IVAP. The consumed power is 7 W. In its first in vivo trial, IAVP was sewed to aortic valve place of a 80 kg pig, without harm to adjacent tissue and organs.