Dawson T W, Stuchly M A
Department of Electrical & Computer Engineering, University of Victoria, BC, Canada.
Phys Med Biol. 1998 May;43(5):1059-74. doi: 10.1088/0031-9155/43/5/002.
The recent development of anatomically derived high-resolution voxel-based models of the human body suitable for electromagnetic modelling, and of effective methods for computing the associated induction, has resulted in numerical estimates of organ-specific dosimetry for human exposure to low-frequency magnetic fields. However, these estimates have used an isotropic conductivity model for all body components. More realistic estimates should account for the anisotropy of certain tissues, particularly skeletal muscle. In this work, high-resolution finite-difference computations of induced fields are used to estimate the effects of several extremal realizations of skeletal muscle anisotropy on field levels in various organs. It is shown that, under the present assumptions (anisotropy ratios up to 3.5:1), the resulting dosimetric values can vary by factors of between two or three for tissues other than muscle and up to 5.4 for muscle, despite the unchanged nature of the conductivity model used for all other body components.
近期已开发出适用于电磁建模的、基于人体解剖学的高分辨率体素模型,以及用于计算相关感应的有效方法,这使得能够对人体暴露于低频磁场时的器官特异性剂量进行数值估计。然而,这些估计对所有身体成分都使用了各向同性电导率模型。更符合实际的估计应考虑某些组织的各向异性,尤其是骨骼肌。在这项工作中,利用感应场的高分辨率有限差分计算来估计骨骼肌各向异性的几种极端情况对各器官中场水平的影响。结果表明,在当前假设(各向异性比高达3.5:1)下,尽管用于所有其他身体成分的电导率模型性质不变,但除肌肉外的其他组织所得到的剂量值可能相差两到三倍,而肌肉的剂量值相差可达5.4倍。