PDF(Sci-hub)
Abstract：
Standards for human exposure to electromagnetic fields typically express maximum permissible exposure limits as a function of frequency. Often, these limits have been derived from experiments or theoretical models involving sinusoidal waveforms. In many practical situations, however, the relevant waveforms of interest may not be sinusoidal, such as with waveforms having harmonic distortion, or with pulsed waveforms. This paper evaluates methods for applying sinusoidal exposure standards to non-sinusoidal waveforms in the frequency regime below a few MHz where electrostimulation is the dominant mechanism. Waveforms treated include those of a pulsed or mixed frequency variety. We evaluate acceptance criteria for mixed frequency exposure using summation formulae cited by IEEE C95.1, ICNIRP, and NRPB. This is carried out using a Fourier synthesis of various waveshapes. Also evaluated is an acceptance criterion based on the peak of the exposure waveform. Excitation thresholds are evaluated using a myelinated nerve model that accounts for the nonlinear electrodynamics of the neural membrane. It is shown that a method based on the peak and phase duration of the in situ field waveform provides a typically conservative test for compliance with non sinusoidal waveforms. An alternate method, based on amplitude summation of the Fourier components of the applied waveforms, can also provide a meaningful test, albeit a more conservative one.
摘要：
人类暴露于电磁场的标准通常将最大允许暴露极限表示为频率的函数。通常,这些限制是从涉及正弦波形的实验或理论模型中得出的。在许多实际情况下,然而,感兴趣的相关波形可能不是正弦波，例如具有谐波失真的波形，或脉冲波形。本文评估了在低于几MHz的频率范围内将正弦暴露标准应用于非正弦波形的方法，其中电刺激是主要机制。所处理的波形包括脉冲或混合频率变化的波形。我们使用IEEEC95.1、ICNIRP、NRPB。这是使用各种波形的傅立叶合成来执行的。还评估了基于曝光波形的峰值的验收标准。使用考虑神经膜的非线性电动力学的有髓神经模型来评估激发阈值。表明，基于原位场波形的峰值和相位持续时间的方法为与非正弦波形的符合性提供了典型的保守测试。另一种方法，基于所应用波形的傅立叶分量的振幅求和，还可以提供有意义的测试，虽然比较保守.
