非均匀低频环境磁场等效源重构及人体曝露剂量学研究

人体曝露于非均匀低频磁场时，体内感应电场可能对神经系统产生瞬时刺激效应。由于环境电磁场和人体的复杂性，感应电场在体内的分布情况是未知的。现有研究仅使用了简化的辐射源模型和人体模型，因此计算结果存在一定的误差。目前尚缺乏实际非均匀磁场曝露的剂量学研究。为此，本项目以无线充电系统的低频电磁安全性问题为例展开研究，提出了基于径向基函数网络的复杂环境磁场的源重构建模方法，以及基于等效张量电导率的体内曝露剂量数值计算误差抑制方法。结合复杂人体体素模型实现体内感应电场、比吸收率和体温升高的准确计算，揭示非均匀环境电磁场与人体耦合机理，探讨各曝露剂量保守性与频率、磁场均匀性等参数的关系，最后利用大规模人体模型实现曝露剂量的个体间差异性分析，考察曝露剂量限值对人群的适用性。研究成果可以为低频电磁剂量学研究提供新的思路，为准确评价电器设备的人体内曝露剂量提供数据支撑和方法参考。

When the human body is exposed to a non-uniform low-frequency magnetic field, the induced electric field in the body may cause an instant stimulation effect on the nervous system. Due to the complexities of the environmental electromagnetic field and the human body, the distribution of the induced electric field in the body is unknown. Existing studies only adopted simplified radiation source models and human body models, certain errors in the calculation results can hence be expected. Currently, there is a lack of dosimetry studies on actual non-uniform magnetic field exposure. To this end, taking the low-frequency electromagnetic safety problem of wireless charging systems as an example, this project proposes a source reconstruction modelling method for complex environmental magnetic fields based on radial basis function network and an equivalent tensor conductivity model to suppress the numerical error of low-frequency dosimetry computation. The project will realize accurate calculations of the induced electric field, specific absorption rate and body temperature rise in the complex voxel human body model, and will reveal the coupling mechanism of the non-uniform environmental electromagnetic field and the human body. The relationship between the conservativeness of each exposure dose and the parameters such as frequency and magnetic field uniformity will also be discussed. Finally, large-scale human models will be used to realize the analysis of the inter-subject variabilities in exposure doses, and to investigate the applicability of exposure limits to the population. The outcomes of this project can provide new ideas for low-frequency electromagnetic dosimetry research, and provide data support and method reference for accurate evaluation of human exposure dose of electrical appliance.