Relationship of External Field Strength With Local and Whole-Body Averaged Specific Absorption Rates in Anatomical Human Models
Relationship of External Field Strength With Local and Whole-Body Averaged Specific Absorption Rates in Anatomical Human Models
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DOI：
10.1109/access.2018.2880905
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发表时间：
2018-11
期刊：
影响因子：
3.9
通讯作者：
K. Taguchi;I. Laakso;Katsuaki Aga;A. Hirata;Y. Diao;J. Chakarothai;T. Kashiwa
中科院分区：
文献类型：
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作者：
K. Taguchi;I. Laakso;Katsuaki Aga;A. Hirata;Y. Diao;J. Chakarothai;T. Kashiwa
国际非电离辐射防护委员会（ICNIRP）指南和IEEE C95.1标准目前正在修订中。在指南/标准中，频率高于100 kHz的电磁场暴露的主要效应是热效应。全身和10 g平均比吸收率（SAR），这是替代核心和局部温度升高，分别被设置为暴露评估的指标。对应于SAR限值的外部场强或入射功率密度也用作实际合规性目的的度量。虽然SAR的限值在指南/标准中是相同的，但在中频范围（100 kHz-100 MHz）内，外部场强的限值相差7.4-12.9倍。由于标准/指南是在使用解剖学人体模型进行计算之前发布的，因此有必要通过使用人体模型进行计算来重新审视SAR与外部场强之间的关系。还使用不同的数字代码进行相互比较，以验证结果。对于主要发现，正如预期的那样，在本文考虑的频率范围内，10 g平均SAR对全身暴露的限制性较小。研究还发现，SAR和外部场强之间的关系是令人满意的，但更保守的ICNIRP指南，而在IEEE标准中有轻微的差异低于30 MHz。计算结果可为根据科学结果修正允许外场强度提供参考。
The International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines and the IEEE C95.1 standard are currently under revision. In the guidelines/standard, the dominant effect for electromagnetic field exposures at frequencies above 100 kHz is the thermal effect. The whole-body-and 10g-averaged specific absorption rates (SARs), which are surrogates for core and local temperature elevations, respectively, are set as metrics for exposure evaluation. The external field strengths or incident power density, corresponding to the limit for SARs, are also used as metrics for practical compliance purposes. Although the limits for the SARs are identical amongst the guidelines/standard, the limits for the external field strengths differ by a factor of 7.4–12.9 in an intermediate frequency range (100 kHz–100 MHz). Due to the fact that the standard/guidelines were published before the computation with anatomical human models was available, it is worth revisiting the relationship between the SARs and external field strengths by computations using the human models. Intercomparison using different numerical codes was also performed to verify the results. For the main finding, as expected, the 10g-averaged SAR was a less restrictive factor for whole-body exposure over the frequencies considered in this paper. It was also found that the relationship between SARs and external field strength was satisfied, but was more conservative in the ICNIRP guidelines, whereas there were slight discrepancies below 30 MHz in the IEEE standard. The computational results would be useful for revising the permissible external field strength based on scientific results.