外磁驱动轴流式血泵磁场分布及红细胞电磁特性分析

外磁驱动轴流式血泵较强的磁场强度会对血液及周围组织细胞产生影响，因此对血泵及其周围红细胞进行电磁场理论计算和仿真分析。利用ANSYS Electronics Desktop中3D瞬态磁场模块对血泵进行瞬态磁场仿真，用理论方法建立细胞膜磁场分布模型，综合利用3D瞬态电场和磁场模块对红细胞膜及其内外电磁场进行研究。给出了血泵稳定状态时的3D和2D磁感应强度分布云图，得到了细胞膜受到的最大磁感应强度值；通过最大磁感应强度值和血泵工况特点得到红细胞膜电场时域上的分布规律和幅值；综合细胞膜静息电位得到细胞膜电场耦合分布规律；基于以上条件求得细胞膜上感应磁场分布及细胞膜所受最大磁场力。尽管钕铁硼材料剩余磁感应强度很大，但血液和红细胞所受最大磁感应强度值仅为812 mT。由此得到的各项红细胞电磁特性参数值可为红细胞受驱动磁场影响下受到的电磁损伤和血泵的临床应用以及优化设计提供理论基础。

Electromagnetic characteristics of outside magnetic driving axial flow blood pump and peripheral red blood cells

The strong magnetic induction intensity of outside magnetic driving axial flow blood pump has an effect on the blood and surrounding tissues and cells. Therefore, performing a theoretical calculation and simulation analysis for the electromagnetic field of the blood pump and peripheral red blood cells is necessary. Herein we use three-dimensional (3D) transient magnetic field module in ANSYS Electronics Desktop to simulate the transient magnetic field, and establish the model of magnetic field distribution in the cell membrane with theoretical method. Subsequently, 3D transient electric field in combination with magnetic field module is applied to analyze the red cell membrane and its internal and external electromagnetic fields. The 3D and two-dimensional magnetic induction intensity distributions with blood pump in the steady state are given and the maximum magnetic induction intensity acting on the cell membrane is obtained. According to the maximum magnetic induction intensity and the characteristics of blood pump, we obtained the distribution law and amplitude of the electric fields of red cell membrane in time domain. The electric field coupling distribution of the cell membrane is obtained by comprehensively considering the resting potential of the cell membrane. Based on the above-mentioned conditions, the induction magnetic field distribution of the cell membrane and the maximum magnetic field force on the cell membrane are able to be calculated. Despite the great residual magnetic induction of NdFeB materials, the maximum magnetic induction intensity acting on blood and red blood cells is only 812 mT. The electromagnetic properties of red blood cells provide the theoretical basis for the analysis of electromagnetic damages to red blood cells under the influence of the driven magnetic field, as well as the clinical application and the optimal design of the blood pump structure.