Developed of spiral vortex-type artificial heart

澳大利亚的脉冲式脑室辅助装置(VAD)被命名为“螺旋涡流”(SV)泵，这是因为泵壳在运行过程中形成了连续的流线。在澳大利亚进行的慢性动物实验中，将SV泵放置在绵羊身体的左侧。在常规课程中，一只实验羊在手术后几个小时就可以站起来。在实验期间，绵羊可以在容器里吃、喝和睡觉。VAD转流流量3.0~4.0 L/min时，血浆游离血红蛋白<10 mg/dl。目前，动物实验正在进行中，以证实该系统在接近真实世界的条件下的优越性。然而，在开发临床质量模型之前，必须通过工程分析来实现SV设计的最优化。为了获得SV设计的基本数据，在日本计划使用两种不同的SV外壳进行比较流动可视化研究。水动力试验表明，锥形和拱形SV型泵在泵流量和进口水锤方面没有明显差异。但在收缩过程中，锥形泵的出流速度始终低于圆顶形泵。在舒张期，圆锥形的周边血流速度也较低。建议在舒张期采用国产，以减少D-H交界处的滞留，而在收缩期宜采用锥形，以减小剪应力。应根据这些数据进行最优的SV住宅设计。

The Australian pulsatile ventricular assist device (VAD) has been named the "Spiral Vortex" (SV) pump after the continuous streamlines which develop within the pump housing during operation. In the chronic animal experiments performed in Australia, the SV pump was placed on the left side of the sheep's body. In a regular course, an experimental sheep can stand up in a few hours after the operation. The sheep can eat, drink and sleep in the container for the duration of the experiment. During VAD pumping with the bypass flow of 3.0-4,0 L/min, the level of plasma free hemoglobin was less than 10 mg/dl. At present, animal experiments are underway to confirm the superiority of the system in near "real-world" conditions. However, optimization of the SV design must be achieved through an engineering analysis prior to the development of a clinical quality model.In order to obtain fundamental data on the SV design, a comparative flow visualization study was planned in Japan using two different SV housings. Hydrodynamics test revealed that no significant difference in pump flow and inlet waterhammer between cone-shaped and dome-shaped SV pumps. However, outflow velocities in the cone-shaped pump were consistently lower than that in the dome-shaped during systole. and, peripheral flow velocities in the cone-shaped were also lower during diastole. Then, the domeshape recommended during the diastolic phase for decreasing the stagnation at D-H junction, whereas the cone-shape was recommended during the systolic phase for minimizing shear stress. The optimal SV housing design should be approached in the light of this data.