極低周波磁界ばく露によるボクセル人体モデル内誘導電界の数値誤差評価

摘要

人体が極低周波の磁界をばく露すると，人体内部には電界や電流が誘導される．これらの体内誘導量は，神経系や筋肉といった興奮性組織に対して，刺激などの直接影響を引き起こす可能性がある．電磁界の人体影響を防護するためにICNIRPガイドラインでは中枢神経系における電流密度に対して，IEEE安全規格では人体各組織における誘導電界に対して，基本制限と呼ばれる体内誘導量の許容値を設けている．%Voxel human body models are used in computational dosimetry in order to evaluate in-situ electric field for electric and magnetic field exposure. It is known that in-situ electric field may include some computational errors caused by stair-casing approximation of human body. In a previous study, the 99 percentile value of in-situ electric was proposed as an alternative measure instead of the maximum value for compensating the above-mentioned computational error. However, the discussion therein was limited to homogeneous or two-layer sphere models. In the present study, we investigate the effectiveness of the 99th percentile value of in-situ electric field with three-layer sphere and anatomical human model. In addition, we examine the influence of model resolution on in-situ electric field. As a result, the 99th percentile value of in-situ electric field was in good agreement with the maximum value of analytical solution. The effect of model resolution on the 99th percentile value of in-situ electric field was marginal for the multi-layer sphere and anatomically-based model.