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Brain & Nervous System

Modeling of EEG electrode artifacts and thermal ripples in human radiofrequency exposure studies.

No Effects Found

Murbach, M., Neufeld, E., Christopoulou, M., Achermann, P. and Kuster, N. · 2014

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The study rejected three hypotheses for how radiofrequency exposure might affect EEG, finding no support for enhanced induced fields, electrode-related temperature increases, or thermal pulsing.

Plain English Summary

Summary written for general audiences

Researchers evaluated three hypotheses about how radiofrequency exposure could affect EEG by using numerical simulations and experimental assessments with phantoms and anatomical human models. They found that induced fields cause less than a 20% increase in 10 g-averaged SAR, that worst-case electrode placement raises skin temperature by at most 0.31 °C and brain temperature by less than 0.1 °C, and that temperature ripples from RF pulses are below 0.001 °C for GSM-like signals and below 0.004 °C for higher pulse energy. These local short-term temperature elevations are unlikely to change brain physiology during the time period from minutes to several hours after exposure. Thus, the mechanism of interaction between RF and changes in the EEG power spectrum remains unknown.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 2.14 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 2.14 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study. The study examined exposure from: 900 and 2140 MHz

Study Details

The effects of radiofrequency (RF) exposure on wake and sleep electroencephalogram (EEG) have been in focus since mobile phone usage became pervasive. It has been hypothesized that effects may be explained by (1) enhanced induced fields due to RF coupling with the electrode assembly, (2) the subsequent temperature increase around the electrodes, or (3) RF induced thermal pulsing caused by localized exposure in the head.

We evaluated these three hypotheses by means of both numerical and experimental assessments made wit...

Our results indicate that hypothesis 1 can be rejected, as the induced fields cause <20% increase in...

Cite This Study
Murbach, M., Neufeld, E., Christopoulou, M., Achermann, P. and Kuster, N. (2014). Modeling of EEG electrode artifacts and thermal ripples in human radiofrequency exposure studies. Bioelectromagnetics. 2014 . doi: 10.1002/bem.21837.
Show BibTeX
@article{murbach_2014_modeling_of_eeg_electrode_3260,
  author = {Murbach and M. and Neufeld and E. and Christopoulou and M. and Achermann and P. and Kuster and N. },
  title = {Modeling of EEG electrode artifacts and thermal ripples in human radiofrequency exposure studies.},
  year = {2014},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/24523224/},
}
PubMed: 24523224

Cited By (16 papers)

View all 16 citing papers on Semantic Scholar

Quick Questions About This Study

The hypotheses were that RF effects on EEG could be explained by enhanced induced fields from electrode coupling, temperature increases around electrodes, or RF-induced thermal pulsing.
Induced fields cause less than a 20% increase in 10 g-averaged SAR, leading to rejection of hypothesis 1.
Worst-case electrode placement produced a maximum skin temperature increase of 0.31 °C and brain temperature elevations below 0.1 °C.
The maximum temperature ripple was below 0.001 °C for GSM-like signals and below 0.004 °C for 20-fold higher pulse energy, offering no support for hypothesis 3.
The mechanism of interaction between RF and changes in the EEG power spectrum remains unknown.