摘要
目的:改进先前研制的微型心尖轴流泵,去除轴流叶轮的机械轴支持系统,实现叶轮在无机械轴承支持条件下的完全悬浮。方法:全悬浮微型心尖轴流泵由泵筒、轴流叶轮、尾导叶等组成,轴流叶轮设置在泵筒内,无机械转轴及支持轴承,利用定子磁力和流体动压实现叶轮的全悬浮。尾导叶为无轮毂中空结构,由轴流泵泵筒内壁向中心伸出,使中心区域形成血流通道。结果:全悬浮微型心尖轴流泵样机直径19 mm、长50 mm,在输出压力100 mmHg(1 mmHg=133.322 Pa)条件下,泵转速约16 000 r/min时流量可达5 L/min,在轴流叶轮转速超过6 000 r/min时可实现稳定的全悬浮,溶血指数为0.12 g/100 L。结论:该磁液悬浮轴流泵的流体力学特性和血液相容性初步达到左心辅助的要求,可进行动物体内植入实验,观察其长期心脏辅助效果及血液相容性。
Objective To suspend the impeller of axial flow pumps by hydrodynamic and magnetically levitated force.Methods The newly developed miniature apex-axial pump was composed of a cylindrical pump house,an impeller with magnetic rotor and a diffuser.The axial displacement of the impeller was restricted by the magnetic field formed by the rotor and the electromagnetic stator.A tiny gap,the hydrodynamic levitating gap,was formed between the blade tip of the impeller and pump house since the diameter of impeller was slightly less than the inner-diameter of the cylindrical pump house.Hydrodynamic force was formed inside this gap on rotating of the impeller,limiting its radial movement.Thus the impeller was fully suspended by hydrodynamic and magnetic force.An outlet diffuser was arranged behind the impeller to enhance the pump efficiency,with its blades projected directly from the wall of the pump house,eliminating the center hub which was usually for holding the diffuser blades,making a hollow space in the diffuser center.This design allowed some blood flow through the centric passage to wash out the ＂dead area＂ behind the impeller,in favor of enhancement of antithrombotic performance.Results Currently the prototype of the miniature apex-axial was 19 mm in diameter and 50 mm in length,yielding a flow rate of 5 L/min at 100 mmHg pressure with a rotating speed of 16 000 r/min.The normalized hemolysis index（NIH） was 0.12 g/100 L.Conclusion The newly developed miniature apex-axial with levitated impeller is feasible for left ventricular assistance,just for in vivo animal test in future studies.
出处
《医疗卫生装备》
CAS
2013年第10期21-24,共4页
Chinese Medical Equipment Journal
关键词
磁液悬浮轴流泵
心脏辅助装置
人工心脏
axial pump with hydrodynamic-magnetically levitated impeller
heart assist device
artificial heart
