Area-Averaged Transmitted Power Density at Skin Surface as Metric to Estimate Surface Temperature Elevation

Funahashi, Daisuke; Hirata, Akimasa; Kodera, Sachiko; Foster, Kenneth R.

doi:10.1109/access.2018.2883733

Cited by 50 publications

(34 citation statements)

References 25 publications

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“…Using the ratio of the surface temperature elevation to the IPD for a one-dimensional tissue modelskin (i.e., assuming plane wave exposure that is uniform over the entire tissue boundary), based on data in [7], we could further estimate the temperature increase. From Fig.…”

Section: Resultsmentioning

confidence: 99%

“…A completion of the metrics has been proposed in the previous two years, to fill up the newly identified gaps regarding: a) time-variation of the emitted signals -which needs an improved averaging process; b) in the case of pulsed fields the fluence was proposed as a metric, and a limit of its value can be established, which depends on frequency and pulsewidth [7][8][9]. Fluence, a term imported from ionizing radiation dosimetry, refers to the radiant energy received by a surface per unit area (J/m 2 ) and is similar to the integrated energy density (IED).…”

Section: Introductionmentioning

confidence: 99%

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Non-Stationary Statistics With Amplitude Probability Density Function for Exposure and Energy Density Reporting Near a Mobile Phone Running 4g Applications

Bechet¹

2020

PIER M

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Present contribution introduces, for the first time, the description of human exposure dynamics to mobile phone radiation by implementing the use of in-air integrated energy density (IED) evolution in time. Using the amplitude probability density (APD) function capability of a real-time spectrum analyzer, we demonstrate the differences in exposure due to five different mobile applications running in Long Term Evolution (LTE) standard, based on energy deposited in air: voice call; voice over LTE (VoLTE); video call, file download and live streaming. This exposimetric method will be of great interest also for the new 5G communication standard. The superiority of the approach has three branches: a) integrated APD allows a sample rate of the order of 0.6 × 10 8 /s which is equivalent to an extremely agile tracing of the power level change in LTE communication standard (happening at every 6.67 µs); b) momentary and mean IED accumulation rate can be computed, and minute differences between mobile applications may be observed during their running time; c) the superficial tissue temperature increase may be rapidly estimated after the period of use of one specific wireless application in the GHz frequency range. The method implemented here also provides the means for rapid usage profile expectancy assessment of a mobile phone user.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Non-Stationary Statistics With Amplitude Probability Density Function for Exposure and Energy Density Reporting Near a Mobile Phone Running 4g Applications

Bechet¹

2020

PIER M

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“…The analysis of superficial tissues from modeled commercial sources (i.e., mobile phone) that operated in the 900 and 1800 MHz bands demonstrated that exposure of skin tissues might well exceed 40 W/kg at the cell level [8]. In addition, the body-worn new emerging wireless devices also expose the skin to radiation [9]. The WHO Fact sheet No.…”

Section: Rf Exposure Of Mobile Wireless Technologymentioning

confidence: 99%

Evaluation of Inflammation by Cytokine Production Following Combined Exposure to Ultraviolet and Radiofrequency Radiation of Mobile Phones on 3D Reconstructed Human Skin In Vitro

Szilágyi

Németh

Bakos

et al. 2020

IJERPH

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The absorption of exposure to radiofrequency (RF) emitted by wireless devices leads to a high specific absorption rate in the skin. Ultraviolet (UV) radiation can induce several damages to the skin. The aim of this study was to examine whether combined, consecutive exposure to solar UV radiation and 1950 MHz RF exposure of third generation (3G) mobile system have any effect on inflammation processes in the skin. Under in vitro experiments, the inflammation process was examined by cytokines (IL-1α, IL-6, and IL-8) and MMP-1 enzyme secretion on 3D full thickness human skin model. The RF exposure was applied before or after UV irradiation, in order to study either the possible cooperative or protective effects of exposure to RF and UV. We did not find changes in cytokines due to exposure to RF alone. The RF exposure did not enhance the effects of UV radiation. There was a statistically not-significant decrease in cytokines when the skin tissues were pre-exposed to RF before being exposed to 4 standard erythemal dose (SED) UV compared to UV exposure alone. We found that RF exposure reduced the previously UV-treated MMP-1 enzyme concentration. This study might support the evaluation of the effects on the skin exposed to microwave radiation of 5G mobile technology.

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“…To prevent excess skin temperature elevation, surrogate internal electrical quantities and their corresponding external field strengths/power densities have been prescribed in the guidelines/standards. In frequency ranges above 6 GHz, including 28 GHz, which is the frequency band assigned to 5G, absorbed or epithelial power density (APD) [18] and incident power density (IPD) are used for basic restrictions and reference levels for local exposure, respectively [13], [16]. These metrics correspond to internal and external physical quantities, where the latter is conservatively derived from the former.…”

Section: Introductionmentioning

confidence: 99%

Skin Temperature Elevation for Incident Power Densities From Dipole Arrays at 28 Ghz

et al. 2020

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The relationship between skin temperature elevation and incident power density (IPD) from radio-frequency near-field exposure at 28 GHz for different angles of incidence is evaluated computationally in this study. The averaging scheme of the IPD is crucial for determining the maximum allowable exposure levels of wireless equipment to comply with certain standards/regulations. However, it is still unclear which component of the IPD (i.e., the norm or normal component to the human body) is more related the temperature elevation. In the case of four-element dipole arrays, the distances between the model and the antenna were 15 and 30 mm in transverse-electric-and transverse-magnetic-like polarized waves, respectively, and in the case of eight-element dipole arrays, the distances were 45 mm from the center of the array. From our computational results for four-and eight-element dipole arrays, we confirmed that the normal component of the IPD provides better correlation with the surface skin temperature, regardless of angle of incidence, particularly for smaller angles of incidence (<30 •). The enhancement of the ratio of the temperature increase to IPD was observed around the Brewster's angle, which is mainly attributable to the difference in transmittance at the body surface. This exposure scenario may not occur as the antennahuman distance was too large to consider compliance at the closest distance. In terms of output power, the most restrictive condition for compliance is shown to be normal incidence, suggesting the importance of compliance for such exposure scenarios. Furthermore, the absorbed power density proved to be an appropriate metric to monitor in relation to skin temperature elevation.

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Area-Averaged Transmitted Power Density at Skin Surface as Metric to Estimate Surface Temperature Elevation

Cited by 50 publications

References 25 publications

Non-Stationary Statistics With Amplitude Probability Density Function for Exposure and Energy Density Reporting Near a Mobile Phone Running 4g Applications

Non-Stationary Statistics With Amplitude Probability Density Function for Exposure and Energy Density Reporting Near a Mobile Phone Running 4g Applications

Evaluation of Inflammation by Cytokine Production Following Combined Exposure to Ultraviolet and Radiofrequency Radiation of Mobile Phones on 3D Reconstructed Human Skin In Vitro

Skin Temperature Elevation for Incident Power Densities From Dipole Arrays at 28 Ghz

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