The correlation between mass-averaged SAR and temperature elevation in the human head model exposed to RF near-fields from 1 to 6 GHz.
In the present study, we investigate the relationship between the mass-averaged specific absorption rate (SAR) and temperature elevation in anatomically based Japanese head models due to the dipole antenna. A homogeneous cubical model is also used as a basis for the investigation. The frequency region considered is from 1 to 6 GHz. We focused on the averaging mass of SAR, which maximizes the correlation with local temperature elevation. An averaged SAR over 10 g was found to reasonably correlate with local temperature elevation even for frequencies from 3 to 6 GHz. The dominant factor influencing the correlation between mass-averaged SAR and temperature elevation is suggested to be the thermal diffusion length in biological tissue, together with the penetration depth of radio-frequency waves. The correlation of local temperature elevation to mass-averaged SAR is largely influenced by the blood perfusion rate, while at most 10% or less is due to the pinna, model inhomogeneity and the antenna position relative to the head model.
Hirata
Akimasa
A
Nagoya Institute of Technology, Japan. ahirata@nitech.ac.jp
Fujiwara
Osamu
O
D000042:Absorption; D000328:Adult; D006257:Head / Q000528:radiation effects*; D006801:Humans; D008297:Male; D008953:Models, Anatomic; D011829:Radiation Dosage; D011846:Radio Waves; D013696:Temperature