植入式微型轴流血泵的研制及实验研究

目的描述研制的一种轴流泵式心脏辅助装置。方法自制的模拟循环台架,以35%甘油水溶液为循环介质,密度与黏滞性均接近于血液。测定泵的输入电流、电压、转速、输出流量、输出压力、泵效率等参数,通过回归推断各参数的相关特性。加等载荷超速运行,以泵的效率为反映泵特性的劣化程度,以流体力学特性下降1%为泵损坏标准,以此来推算泵的理论工作寿命。溶血实验采用健康羊血500 mL,根据血浆中游离血红蛋白随循环时间延长而增加的数值来计算溶血指数(IH),判定溶血程度。结果轴流泵的流体力学特性良好,流量、压力与转速度均大体呈现正相关的关系。最佳的工况点位于100 mm Hg的输出压力附近。对血泵的溶血特性测定结果表明,每分钟5 L流量,输出压力为100 mm Hg条件下,溶血指数为0.025左右。溶血作用在实际应用范围内非常轻微。结论本实验结果表明,该装置的各项性能指标已经达到了长期植入体内的要求。

Development of implantable miniature axial pump

Objective To describe a new axial blood pump developed for ventricular assist. Methods To test the hydrodynamic characteristic of the pump,a testing circuit was built and primed with 35% glycerin solution which similar to the blood in density and viscidity.The input electric current,voltage,rotary speed,output flux and output pressure of the pump were tested.The regression relation of these parameters was deduced.The pump was operated in an excessive rotary speed to estimate its durability and was determined as damaged if its efficiency was dropped by 1%.To test the hemolysis characteristic of the pump;the circuit was primed with 500 mL fresh goat blood.Blood samples were collected after the circulating started and the free hemoglobin,which was increased with operating time,was tested.The index of hemolysis(IH) was then calculated. Results The hydrodynamic characteristic of the pump was satisfied.The output flux and output pressure were proportionally related to rotary speed.The optimal working state of the pump was at a load of 100 mm Hg output pressure.The IH was 0.025 if the pump was set at 5 L/min of flow rate and the pressure of 100 mm Hg,The effect of hemolysis is slightly in practice use. Conclusion The pump has some excellent characteristics and the parameters were accord with the actual utility.