旋转血泵产生低溶血搏动流的方法

为减少心室辅助装置中叶轮泵输出搏动流对血液成分的破坏作用，我们将泵的入口和叶轮外形轮廓设计成锥形，研制出博动流轴流泵；并设计出扭曲形叶片的叶轮，周期性的改变叶轮的转速，研制出搏动流离心泵。理论分析和实验表明这两种类型的装置均无明显附加紊流产生，也没有对血液成分产生破坏，具有较强实用性。

Pulsatile Rotary Pumps with Low Hemolysis

As is well known, a pulsatile flow is important in assisted circulation but it is difficult to produce a pulsatile flow with rotary pump, because excessive hemolysis will be generated. The authors have found that the turbulent shear is the main factor for red cell damage and therefore the key point of pulsatile rotary pumps is to reduce the turbulence by producing a pulsatile flow. In the authors' pulsatile axial pump, the pulsatile flow is obtained by axial reciprocation of constant rotating impeller; the rotation and reciprocation of the impeller are driven separately by a DC motor and a pneumatic device. Though a physiological pulsatile flow could be achieved and turbulence would not increase remarkably because the impeller rotates constantly, a second driver except a DC motor is nevertheless necessary, thus the system will become complicated. In the authors' pulsatile radial pump, a pulsatile flow is achieved by changing the rotating speed of the impeller periodically. Turbulence is minimized by a special design of twisted vanes which enable the blood flow to change its direction rather than its dimension during periodic change of rotating speed. Hempolysis tests demonstrated that the index of hemolysis(IH) of the author's pulsatile radial pump is 0.020, with is slightly more than that of the author's nonpulsatile radial pump(IH=0.015). Animal experiments indicated that the pulsatile radial pump can assist the circulation of calves for several months without harm to blood elements and organ functions of the recipients.