O2 Thermal sensation threshold (TST) when exposed to millimeter waves (MMWS) in japanese

Abstract

Objectives The millimeter-wave usage have recently expanded in our daily life, such as automobile collision avoidance radar system, airport active scanner system, WiGig, and so on. Thermal sensation induced by the millimeter-wave EMF exposure has not been fully studied. For the millimeter-wave guideline, we need objective data of the sensation threshold to millimeter waves. Methods This study was approved by the ethical committee of FMU and supported by the fund from the Ministry of Internal Affairs and Communications, Japan. TST to MMW was measured in 30 Japanese healthy adult volunteers. 95 GHz or 40 GHz MMWs were exposed to the palm of over three different sized exposed area more than 20 times. The subjects pressed a response button when she/he felt some sensation in each trial. We estimated the threshold evoking thermal sensation with three duration of exposure at 50% probability using two-dimensional cumulative distribution function and the maximum likelihood method. Results In both 95 GHz and 40 GHz MMW exposures, the longer the stimulation duration, or the larger the exposed area, the lower was TST. These non-linear relations of TST with the duration and area size of MMW stimulation are compatible with those of previous studies. Discussion Our present results support that our measurement method is reliable for TST measurement, and we are now measuring TSTs to 40 GHz in normal, male and female normal volunteers with different ages. Conclusions Normal values of TST to MMWs for the Japanese person will be established in this study. Significance The results was useful to establish the guideline for the MMWs in Japan.