Okamoto Eiji, Ishida Yuya, Yano Tetsuya, Mitamura Yoshinori
Graduate School of Science and Engineering, Tokai University, Minami-sawa 5-1-1-1, Minami-ku, Sapporo, 005-8601, Japan,
J Artif Organs. 2015 Jun;18(2):181-4. doi: 10.1007/s10047-014-0806-9. Epub 2014 Nov 19.
The new miniature axial flow pump (valvo pump 2) that is installed at the base of the ascending aorta consists of a six-phase stator, an impeller in which four neodymium magnets are incorporated, and passive magnetic bearings that suspend the impeller for axial levitation. The impeller is sustained by hydrodynamic force between the blade tip of the impeller and the inner housing of the stator. The passive magnetic bearing consists of a ring neodymium magnet and a columnar neodymium magnet. The ring neodymium magnet is set in the stationary side and the columnar neodymium magnet is incorporated in the impeller shaft. Both neodymium magnets are coaxially mounted, and the anterior and posterior passive magnetic bearings suspend the impeller by repulsion force against the hydrodynamic force that acts to move the impeller in the inflow port direction. The passive magnetic bearing was evaluated by a tensile test, and the levitation force of 8.5 N and stiffness of 2.45 N/mm was obtained. Performance of the axial flow pump was evaluated by an in vitro experiment. The passive magnetic bearing showed sufficient levitation capacity to suspend the impeller in an axial direction. In conclusion, the passive magnetic bearing is promising to be one of levitation technology for the third-generation axial flow blood pump.
安装在升主动脉根部的新型微型轴流泵（瓣膜泵2）由一个六相定子、一个内置四个钕磁铁的叶轮以及用于使叶轮轴向悬浮的被动磁轴承组成。叶轮通过叶轮叶片尖端与定子内壳之间的流体动力来支撑。被动磁轴承由一个环形钕磁铁和一个柱状钕磁铁组成。环形钕磁铁设置在固定侧，柱状钕磁铁安装在叶轮轴上。两个钕磁铁同轴安装，前后被动磁轴承通过与作用于使叶轮沿流入端口方向移动的流体动力产生的排斥力来悬浮叶轮。通过拉伸试验对被动磁轴承进行了评估，获得了8.5 N的悬浮力和2.45 N/mm的刚度。通过体外实验对轴流泵的性能进行了评估。被动磁轴承显示出足够的悬浮能力，可在轴向悬浮叶轮。总之，被动磁轴承有望成为第三代轴流血泵的悬浮技术之一。
