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A thermal model for human thresholds of microwave-evoked warmth sensations.

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Riu PJ, Foster KR, Blick DW, Adair ER, · 1997

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Human warmth sensation thresholds from 2.45 to 94 GHz correspond to a localized skin temperature increase of about 0.07°C.

Plain English Summary

Summary written for general audiences

Researchers measured human thresholds for skin warmth sensations at frequencies from 2.45 to 94 GHz. The thermal analysis suggests these thresholds correspond to a localized temperature increase of about 0.07°C at and near the skin surface. The thermal model results were insensitive to blood flow but sensitive to thermal conduction, with sensitivity increasing strongly with frequency. Thermal conduction becomes a dominant factor for surface temperature rise at microwave frequencies over 10 GHz.

Why This Matters

The depth of temperature receptors within 0.3 mm of the surface was not a relevant parameter even at the highest frequency. The temperature increase was calculated at the skin surface or at 175 microm depth using a one-dimensional bioheat equation at incident power levels matching observed thresholds.

Exposure Information

Specific exposure levels were not quantified in this study. The study examined exposure from: 2.45 to 94

Study Details

Human thresholds for skin sensations of warmth were measured at frequencies from 2.45 to 94 GHz.

By solving the one-dimensional bioheat equation, we calculated the temperature increase at the skin ...

The thermal analysis suggests that the thresholds correspond to a localized temperature increase of ...

We conclude with an analysis of the effect of thermal conduction on surface temperature rise, which becomes a dominant factor at microwave frequencies over 10 GHz.

Cite This Study
Riu PJ, Foster KR, Blick DW, Adair ER, (1997). A thermal model for human thresholds of microwave-evoked warmth sensations. Bioelectromagnetics 18(8):578-583, 1997.
Show BibTeX
@article{pj_1997_a_thermal_model_for_2539,
  author = {Riu PJ and Foster KR and Blick DW and Adair ER and},
  title = {A thermal model for human thresholds of microwave-evoked warmth sensations.},
  year = {1997},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/9383246/},
}
PubMed: 9383246

Cited By (38 papers)

Quick Questions About This Study

Human thresholds for skin sensations of warmth were measured at frequencies from 2.45 to 94 GHz.
The thermal analysis suggests the thresholds correspond to a localized temperature increase of about 0.07°C at and near the skin surface.
Even at the highest frequency, the depth of temperature receptors is not a relevant parameter as long as it is within 0.3 mm of the surface.
Thermal conduction becomes a dominant factor for surface temperature rise at microwave frequencies over 10 GHz.
By solving the one-dimensional bioheat equation, the temperature increase was calculated at the skin surface or at a depth of 175 microm at incident power levels corresponding to the observed thresholds.