V M M Flyckt et al 2007 Phys. Med. Biol. 52 2691 doi:10.1088/0031-9155/52/10/004
V M M Flyckt, B W Raaymakers, H Kroeze and J J W Lagendijk
Show affiliationsThe eye is considered to be a critical organ when determining safety standards for radiofrequency radiation. With a detailed anatomy of the human eye and orbit inserted in a whole-head model, the specific absorption rates (SARs) and thermal effects were determined under exposure to a dipole antenna representing a mobile phone operating at 900, 1500 and 1800 MHz with an output power of 1 W. The temperature rise was calculated by taking the blood flow into account either by the Pennes bioheat model or by including the discrete vasculature (DIVA). In addition, a simple spherical model using constant heat transfer coefficients was used. Peak SARs in the humour are 4.5, 7.7 and 8.4 W kg−1 for 900, 1500 and 1800 MHz respectively. Averaged over the whole eyeball, the SARs are 1.7, 2.5 and 2.2 W kg−1. The maximum temperature rises in the eye due to the exposure are 0.22, 0.27 and 0.25 °C for exposure of 900, 1500 and 1800 MHz, respectively, calculated with DIVA. For the Pennes bioheat model, the temperature rises are slightly lower: 0.19, 0.24, 0.22 °C respectively. For the simple spherical model, the maximum temperature rises are 0.15, 0.22 and 0.20 °C. The peak temperature is located in the anterior part of the lens for 900 MHz and deeper in the eye for higher frequencies, and in the posterior part of the lens for 1500 MHz and close to the centre of the eyeball for 1800 MHz. For these RF safety applications, both DIVA and the Pennes bioheat model could be used to relate the SAR distributions to the resulting temperature distributions. Even though, for these artificial exposure conditions, the SAR values are not in compliance with safety guidelines, the maximum temperature rises in the eye are too small to give harmful effects. The temperature in the eye also remains below body core temperature.
87.50.S- Radiofrequency/microwave fields effects
Issue 10 (21 May 2007)
Received 16 August 2006, in final form 16 February 2007
Published 25 April 2007
V M M Flyckt et al 2007 Phys. Med. Biol. 52 2691
Sadie Baldwin and John Gibbons 2003 J. Phys. A: Math. Gen. 36 8393
Claus M Schneider and Gerd Schönhense 2002 Rep. Prog. Phys. 65 1785
R. U. Abbasi et al. 2005 ApJ 622 910
Li Jian-Hua et al 2009 Chinese Phys. Lett. 26 116101
E Díaz-Miguel 1994 Class. Quantum Grav. 11 2833
Boudewijn F Roukema 2000 Class. Quantum Grav. 17 3951
L. E. DeWarf et al. 2003 ApJ 590 357
C Courde et al 2009 Meas. Sci. Technol. 20 127002
P Kidkhunthod and A C Barnes 2009 J. Phys.: Conf. Ser. 190 012076