Clinical Course of High-Frequency Millimeter-Wave (162 GHz) Induced Ocular Injuries and Investigation of Damage Thresholds

Kojima, Masami; Suzuki, Yukihisa; Tasaki, Takafumi; Tatematsu, Y.; Mizuno, Maya; Fukunari, Masafumi; Sekiya, Hiroshi

doi:10.1007/s10762-020-00714-1

Cited by 13 publications

(12 citation statements)

References 13 publications

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“…The 50% probability of ocular damage was higher at 40GHz, 95GHz and 75GHz respectively for given incident power densities [38]. Ocular damage and healing due to RF EMFs exposures at 162GHz were investigated, and results show that 10%, 50%, 90% probability of ocular damage was occurring at 173mW/cm 2 , 252mW/cm 2 , 368mW/cm 2 of incident power densities respectively and 9days are needed to subsidize to normal [39].…”

Section: Human Eyesmentioning

confidence: 99%

Implications of mmWave Radiation on Human Health: State of the Art Threshold Levels

Dilli

2021

IEEE Access

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millimeter (mmWave) frequencies are covering from 30GHz to 300GHz in the electromagnetic spectrum and their uses in various applications like next-generation wireless communication systems (massive 5G telecommunications network), medical devices, airport security and automatic collision avoidance systems are growing vastly in the near future. Therefore, it is important to study the effects of mmWave radiation (non-ionization radiation) on biological systems and biophysical mechanisms. This paper focus on thorough review of nascent literature about current understandings of biological effects and epidemiological studies due to mmWave radiation in human beings. It presents latest guidelines with quantitative electromagnetic field thresholds by considering the realistic exposure scenarios of ''general public'' and ''occupational'' who undergo through wireless communication sources in their daily life. It also gives necessary safety measures to be taken while using the emerging mmWave technologies for future generation wireless communication networks.

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Section: Human Eyesmentioning

confidence: 99%

Implications of mmWave Radiation on Human Health: State of the Art Threshold Levels

Dilli

2021

IEEE Access

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“…Straightforward comparison of these results with other studies is not feasible, because the SAR pattern in the brains of the rats was inhomogeneous; the study used the brain -averaged SAR as the metric for evaluation which also prevents comparison with studies on larger animals. Kojima et al (2018) exposed the eyes of rabbits to millimeter waves at 40, 75, and 95 GHz (extended in 2020 to 162 GHz) and documented damage to the eyes (as well as eyelids) depending on exposure (Kojima et al, 2020).…”

Section: A Review Of Computational Dosimetrymentioning

confidence: 99%

Human exposure to radiofrequency energy above 6 GHz: review of computational dosimetry studies

et al. 2021

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International guidelines/standards for human protection from electromagnetic fields have been revised recently, especially for frequencies above 6 GHz where new wireless communication systems have been deployed. Above this frequency a new physical quantity 'absorbed/epithelial power density' has been adopted as a dose metric. Then, the permissible level of external field strength/power density is derived for practical assessment. In addition, a new physical quantity, fluence or absorbed energy density, is introduced for protection from brief pulses (especially for shorter than 10 s). These limits were explicitly designed to avoid excessive increases in tissue temperature, based on electromagnetic and thermal modeling studies but supported by experimental data where available. This paper reviews the studies on the computational modeling/dosimetry which are related to the revision of the guidelines/standards. The comparisons with experimental data as well as an analytic solution are also been presented. Future research needs and additional comments on the revision will also be mentioned.

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“…In these experiments, the RF-induced temperature increases varied across the corneal surface due to wave reflections from the ocular adnexa including eyelids (Foster et al 2021), leading to considerable variability in peak temperature increases as related to the incident power density on the cornea. Kojima et al (2009Kojima et al ( , 2015Kojima et al ( , 2018Kojima et al ( , 2020) measured thresholds for "slight ocular damage" to the corneal epithelium in groups of 3-15 rabbits exposed to RF energy at 18-162 GHz for 6-or 30-min periods. Corneal temperatures were measured thermographically before and shortly after exposure.…”

Section: Experimental Thermal Pain and Burn Thresholdsmentioning

confidence: 99%

Time-temperature Thresholds and Safety Factors for Thermal Hazards from Radiofrequency Energy above 6 GHz

2021

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Two major sets of exposure limits for radiofrequency (RF) radiation, those of the International Commission on Nonionizing Radiation Protection (ICNIRP 2020) and the Institute of Electrical and Electronics Engineers (IEEE C95.1–2019), have recently been revised and updated with significant changes in limits above 6 GHz through the millimeter wave (mm-wave) band (30–300 GHz). This review compares available data on thermal damage and pain from exposure to RF energy above 6 GHz with corresponding data from infrared energy and other heat sources and estimates safety factors that are incorporated in the IEEE and ICNIRP RF exposure limits. The benchmarks for damage are the same as used in ICNIRP IR limits: minimal epithelial damage to cornea and first-degree burn (erythema in skin observable within 48 h after exposure). The data suggest that limiting thermal hazard to skin is cutaneous pain for exposure durations less than ≈20 min and thermal damage for longer exposures. Limitations on available data and thermal models are noted. However, data on RF and IR thermal damage and pain thresholds show that exposures far above current ICNIRP and IEEE limits would be required to produce thermally hazardous effects. This review focuses exclusively on thermal hazards from RF exposures above 6 GHz to skin and the cornea, which are the most exposed tissues in the considered frequency range.

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Clinical Course of High-Frequency Millimeter-Wave (162 GHz) Induced Ocular Injuries and Investigation of Damage Thresholds

Cited by 13 publications

References 13 publications

Implications of mmWave Radiation on Human Health: State of the Art Threshold Levels

Implications of mmWave Radiation on Human Health: State of the Art Threshold Levels

Human exposure to radiofrequency energy above 6 GHz: review of computational dosimetry studies

Time-temperature Thresholds and Safety Factors for Thermal Hazards from Radiofrequency Energy above 6 GHz

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