Cheng J, Stuchly M A, DeWagter C, Martens L
Department of Electrical and Computer Engineering, University of Victoria, BC, Canada.
Phys Med Biol. 1995 Apr;40(4):495-510. doi: 10.1088/0031-9155/40/4/002.
The induced currents in a model of the human head resulting from use of small hand-held appliances were computed. The source of the induced currents, i.e. the alternating (60 Hz) magnetic field was modelled as a magnetic dipole. The limits of applicability of this model are given. The model of the human head was obtained by translating MRI data into tissue conductivity data. Computations of the distribution of the induced currents were performed using the impedance method. The induced current density rapidly decreases with the distance from the appliance. The maximum, however, predictably is not at the surface, because of the geometry of the head. For typical appliances, the values of the maximum current densities are high as compared to those induced by a uniform magnetic field. Generalized graphs were obtained for the maximum induced current density normalized to the appliance magnetic moment, as a function of the distance from the appliance. These graphs are given for two representative locations of the appliance with respect to the head.
计算了使用小型手持电器时在人体头部模型中产生的感应电流。感应电流的源，即交变（60赫兹）磁场被建模为磁偶极子。给出了该模型的适用范围。人体头部模型是通过将MRI数据转换为组织电导率数据获得的。使用阻抗方法进行感应电流分布的计算。感应电流密度随距电器距离的增加而迅速减小。然而，由于头部的几何形状，最大值可预测地不在表面。对于典型电器，与均匀磁场感应的值相比，最大电流密度的值较高。得到了归一化到电器磁矩的最大感应电流密度作为距电器距离的函数的广义图。这些图给出了电器相对于头部的两个代表性位置的情况。
