Temperature elevation in the human brain and skin with thermoregulation during exposure to RF energy.
Background: Two international guidelines/standards for human protection from electromagnetic fields define the specific absorption rate (SAR) averaged over 10 g of tissue as a metric for protection against localized radio frequency field exposure due to portable devices operating below 3-10 GHz. Tem...
| Publicado en: | BioMedical Engineering OnLine Vol. 17; pp. 1 - 18 |
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| Autores principales: | , , |
| Formato: | Journal Article |
| Publicado: |
BioMed Central
1/8/2018
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=127253861&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 127253861 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 1475925X 1CGX jtl: BioMedical Engineering OnLine issn: 1475925X maglogo: N pubinfo: dt: 1/8/2018 vid: 17 pid: 24147 pub: BioMed Central artinfo: ui: 127253861 127253861 NLM29310661 10.1186/s12938-017-0432-x NLM29310661 127253861 ppf: 1 ppct: 17 formats: tig: atl: Temperature elevation in the human brain and skin with thermoregulation during exposure to RF energy. aug: au: Kodera, Sachiko Gomez-Tames, Jose Hirata, Akimasa affil: Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, 466-8555, Nagoya, Japan sug: subj: Body Temperature Regulation Radiation Effects Brain Radiation Effects Skin Radiation Effects Radio Waves Adverse Effects Body Temperature Body Temperature Radiation Effects Blood Circulation Radiation Effects Skin Blood Supply Models, Biological Skin Physiology Radiation Effects Adult Brain Physiology Brain Blood Supply Male Arthritis Impact Measurement Scales Adult: 19-44 years Male ab: Background: Two international guidelines/standards for human protection from electromagnetic fields define the specific absorption rate (SAR) averaged over 10 g of tissue as a metric for protection against localized radio frequency field exposure due to portable devices operating below 3-10 GHz. Temperature elevation is suggested to be a dominant effect for exposure at frequencies higher than 100 kHz. No previous studies have evaluated temperature elevation in the human head for local exposure considering thermoregulation. This study aims to discuss the temperature elevation in a human head model considering vasodilation, to discuss the conservativeness of the current limit.Methods: This study computes the temperature elevations in an anatomical human head model exposed to radiation from a dipole antenna and truncated plane waves at 300 MHz-10GHz. The SARs in the human model are first computed using a finite-difference time-domain method. The temperature elevation is calculated by solving the bioheat transfer equation by considering the thermoregulation that simulates the vasodilation.Results: The maximum temperature elevation in the brain appeared around its periphery. At exposures with higher intensity, the temperature elevation became larger and reached around 40 °C at the peak SAR of 100 W/kg, and became lower at higher frequencies. The temperature elevation in the brain at the current limit of 10 W/kg is at most 0.93 °C. The effect of vasodilation became notable for tissue temperature elevations higher than 1-2 °C and for an SAR of 10 W/kg. The temperature at the periphery was below the basal brain temperature (37 °C).Conclusions: The temperature elevation under the current guideline for occupational exposure is within the ranges of brain temperature variability for environmental changes in daily life. The effect of vasodilation is significant, especially at higher frequencies where skin temperature elevation is dominant. pubtype: Academic Journal doctype: Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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