50MHz～3GHz电磁辐射下人体中枢神经系统比吸收率计算

Calculation of the specific Absorption rate of the human central nervous system exposed to electromagnetic wave from 50 MHz to 3 GHz

目的:计算并比较不同频率电磁波作用下人体中枢神经系统比吸收率(specific absorption rate,SAR)分布特点,为寻找损伤靶点和设计试验提供剂量学依据。方法:采用时域有限差分法计算人体仿真模型比吸收率及其分布。模型身高1.70m,体重63kg,由42种组织器官共1.4×107个网格单元构成。结果:给出了50MHz～3GHz频率范围、平面波、前后向照射、E和H极化条件下人体中枢神经系统SAR,其中脊髓、小脑和大脑分别在90MHz、250MHz和900MHz达到SAR峰值,分别为0.57,0.28和0.32W/kg。结论:中枢神经系统中的大脑、小脑和脊髓分别在不同的频率处具有高电磁能量的吸收。

Objective：To compare the specific absorption rate （SAR） of the human central nervous system exposed to different electromagnetic waves so as to provide the dosimetric reference for searching for injury targets and designing experiments of bioelectromagnetics. Methods：The finite-difference time-domain method was used for computation of the SARs. An anatomically realistic model with a height of 1.70 m and a mass of 63 kg was selected ,which included 14 million voxels segmented into 42 tissue types. Results： The average SAR values of central nervous system of the model exposed to 50 MHz to 3 GHz, at ante-posterior, E and H polarized planes were obtained with high SAR values found in the spinal cord, cerebellum and cerebrum, which were 0.57 W/kg at 90 MHz, 0.28 W/kg at 250 MHz and 0.32 W/kg at 900 MHz. Conclusion：The high energy absorption was found in human spinal cord, cerebellum and cerebrum exposed to electromagnetic waves at different frequencies.