Research Center for Bioelectromagnetic Interaction (femu), Institute for Occupational, Social and Environmental Medicine, Uniklinik RWTH Aachen University, Aachen, Germany.
Advanced Cardiac Therapeutics, Inc., Santa Clara, CA, USA.
Med Biol Eng Comput. 2021 Jan;59(1):107-119. doi: 10.1007/s11517-020-02284-9. Epub 2020 Dec 2.
Electric contact currents (CC) can cause muscle contractions, burns, or ventricular fibrillation which may result in life-threatening situations. In vivo studies with CC are rare due to potentially hazardous effects for participants. Cadaver studies are limited to the range of tissue's electrical properties and the utilized probes' size, relative position, and sensitivity. Thus, the general safety standards for protection against CC depend on a limited scientific basis. The aim of this study was therefore to develop an extendable and adaptable validated numerical body model for computational CC dosimetry for frequencies between DC and 1 MHz. Applying the developed model for calculations of the IEC heart current factors (HCF) revealed that in the case of transversal CCs, HCFs are frequency dependent, while for longitudinal CCs, the HCFs seem to be unaffected by frequency. HCFs for current paths from chest or back to hand appear to be underestimated by the International Electrotechnical Commission (IEC 60479-1). Unlike the HCFs provided in IEC 60479-1 for longitudinal current paths, our work predicts the HCFs equal 1.0, possibly due to a previously unappreciated current flow through the blood vessels. However, our results must be investigated by further research in order to make a definitive statement. Contact currents of frequencies from DC up to 100 kHz were conducted through the numerical body model Duke by seven contact electrodes on longitudinal and transversal paths. The resulting induced electric field and current enable the evaluation of the body impedance and the heart current factors for each frequency and current path.
电流接触（CC）可能会导致肌肉收缩、灼伤或心室颤动，从而导致危及生命的情况。由于对参与者可能产生潜在的危险影响，因此很少有使用 CC 的活体研究。尸体研究仅限于组织电特性的范围以及所使用探头的尺寸、相对位置和灵敏度。因此，防止 CC 的一般安全标准取决于有限的科学依据。因此，本研究的目的是开发一种可扩展和可适应的验证数值人体模型，用于计算 DC 至 1 MHz 频率之间的 CC 剂量。应用所开发的模型计算 IEC 心脏电流系数（HCF）表明，在横向 CC 的情况下，HCF 是频率相关的，而对于纵向 CC，HCF 似乎不受频率影响。从胸部或背部到手的电流路径的 HCF 似乎被国际电工委员会（IEC 60479-1）低估了。与 IEC 60479-1 中提供的用于纵向电流路径的 HCF 不同，我们的工作预测 HCF 等于 1.0，这可能是由于以前未被注意到的电流流经血管。然而，我们的结果必须通过进一步的研究来调查，以便做出明确的声明。通过七个接触电极在纵向和横向路径上对频率从 DC 到 100 kHz 的电流接触进行了 Duke 数值人体模型的实验。由此产生的感应电场和电流使每个频率和电流路径的身体阻抗和心脏电流系数的评估成为可能。
