Grote V, Lackner H, Kelz C, Trapp M, Aichinger F, Puff H, Moser M
Institute of Noninvasive Diagnosis, JOANNEUM RESEARCH, Weiz, Austria.
Eur J Appl Physiol. 2007 Nov;101(4):495-502. doi: 10.1007/s00421-007-0520-x. Epub 2007 Aug 3.
The therapeutic application of pulsed electromagnetic fields (PEMFs) can accelerate healing after bone fractures and also alleviate pain according to several studies. However, no objective criteria have been available to ensure appropriate magnetic field strength or type of electromagnetic field. Moreover, few studies so far have investigated the physical principles responsible for the impact of electromagnetic fields on the human body. Existing studies have shown that PEMFs influence cell activity, the autonomic nervous system and the blood flow. The aim of this study is to examine the instantaneous and short-term effects of a PEMF therapy and to measure the impact of different electromagnetic field strengths on a range of physiological parameters, especially the autonomic nervous systems, determined by heart rate variability (HRV) as well as their influence on subjects' general feeling of well-being. The study comprised experimental, double-blind laboratory tests during which 32 healthy male adults (age: 38.4+/-6.5 years) underwent four physical stress tests at standardised times followed by exposure to pulsed magnetic fields of varying intensity [HPM, High Performance magnetic field; Leotec; pulsed signal; mean intensity increase: zero (placebo), 0.005, 0.03 and 0.09 T/s]. Exposure to electromagnetic fields after standardised physical effort significantly affected the very low frequency power spectral components of HRV (VLF; an indicator for sympathetically controlled blood flow rhythms). Compared to placebo treatment, exposure to 0.005 T/s resulted in accelerated recovery after physical strain. Subjects with lower baseline VLF power recovered more quickly than subjects with higher VLF when exposed to higher magnetic field strengths. The application of electromagnetic fields had no effect on subjects' general feeling of well-being. Once the magnetic field exposure was stopped, the described effects quickly subsided. PEMF exposure has a short-term dosage-dependent impact on healthy subjects. Exposure to PEMF for 20 min resulted in more rapid recovery of heart rate variability, especially in the very low frequency range after physical strain. The study also showed the moderating influence of the subjects' constitutional VLF power on their response to PEMF treatment. These findings have since been replicated in a clinical study and should be taken into consideration when PEMF treatment is chosen.
多项研究表明，脉冲电磁场（PEMF）的治疗应用可加速骨折愈合并缓解疼痛。然而，目前尚无客观标准来确保合适的磁场强度或电磁场类型。此外，迄今为止，很少有研究探讨电磁场作用于人体的物理原理。现有研究表明，PEMF会影响细胞活性、自主神经系统和血流。本研究的目的是检验PEMF疗法的即时和短期效果，并测量不同电磁场强度对一系列生理参数的影响，尤其是通过心率变异性（HRV）测定的自主神经系统，以及其对受试者总体幸福感的影响。该研究包括实验性双盲实验室测试，期间32名健康成年男性（年龄：38.4±6.5岁）在标准化时间接受了四项身体应激测试，随后暴露于不同强度的脉冲磁场中[高性能磁场（HPM）；Leotec；脉冲信号；平均强度增加：零（安慰剂）、0.005、0.03和0.09 T/s]。在标准化身体运动后暴露于电磁场显著影响了HRV的极低频功率谱成分（VLF；交感神经控制的血流节律指标）。与安慰剂治疗相比，暴露于0.005 T/s可使身体应激后恢复加速。当暴露于更高磁场强度时，基线VLF功率较低的受试者比VLF较高的受试者恢复得更快。电磁场的应用对受试者的总体幸福感没有影响。一旦停止磁场暴露，上述效果很快就会消退。PEMF暴露对健康受试者有短期剂量依赖性影响。暴露于PEMF 20分钟可使心率变异性恢复更快，尤其是在身体应激后的极低频范围内。该研究还显示了受试者固有VLF功率对其对PEMF治疗反应的调节作用。这些发现此后已在一项临床研究中得到重复，在选择PEMF治疗时应予以考虑。
