Developed of spiral vortex-type artificial heart

澳大利亚脉动性心室辅助装置（VAD）被命名为“螺旋涡”（SV）泵，因为在运行过程中泵壳内形成了连续的流线。在澳大利亚进行的慢性动物实验中，SV泵被放置在绵羊身体的左侧。正常情况下，实验羊在手术后几小时内就能站起来。在实验期间，羊可以在容器里吃、喝、睡。旁路流量3.0 ~ 4.0 L/min的VAD泵送期间，血浆游离血红蛋白水平均小于10 mg/dl。目前，动物实验正在进行中，以证实该系统在接近“现实世界”条件下的优越性。然而，SV设计的优化必须在开发临床质量模型之前通过工程分析来实现。为了获得SV设计的基本数据，计划在日本使用两种不同的SV外壳进行比较流动可视化研究。水动力试验表明，锥型和圆顶型SV泵的泵流量和进口水锤无显著差异。然而，在收缩期，锥形泵的流出速度始终低于圆顶泵。舒张期锥体周围流速也较低。然后，在舒张期推荐采用内径型，以减少D-H连接处的停滞，而在收缩期推荐采用锥形，以减少剪切应力。最佳的SV外壳设计应该根据这些数据进行探讨。

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.