ID Number		1563
Study Type		Engineering & Physics
Model		900, 1800, 2100 MHz (GSM) exposure and modeling of SAR distribution using FDTD models (including child vs. adult, headset vs. ear vs. trunk, effect of hand on head SAR).
Details		Dosimetric evaluation of head size on mobile phone RF energy absorption, addressing the child vs. adult exposure issue (both local and whole body). The authors report that smaller head size did not lead to higher SAR values. The project also extends to SAR evaluation for mobile phone compliance testing. The Specific Anthropomorphic Mannequin (SAM) phantom used for testing of mobile phone products (adopted by CENELEC and used in testing to ICNIRP and IEEE compliance specifications), as well as the Generic Twin Phantom, were evaluated using mobile phone transmitters (monopole, helical, patch antenna types) for exposure assessment and data compared to numerical calculations from three high-resolution anatomical models (including a 3 year old child model [3YC], a European female [HR-EF-1], and the Visible Man). The authors report that the SAM phantom provides the most conservative measurements (highest SAR readings, so most stringent in terms of passing compliance) for adults and children for both 900- and 1800-MHz in the tilted and touch positions. In a series of studies funded by BfS, the authors will examine exposure to a variety of sources (0,4 - 10 GHz) in models of children's heads (including the pineal gland, hippocampus, hypothalamus and bone marrow) as well as in whole body children and adults at different sites (including areas that would be exposed from sources positioned at the belt, fannypack, or in a shirt pocket used with a wireless headset). A set of human CAD files for a representative European family is being developed. In particular, liver, kidneys, spleen, gonads, and breast tissues will be evaluated. Recently initiated study under SNSR funding to look at human fetal exposure in public, uncontrolled environments AUTHORS' ABSTRACT: Meier et al. 1997 IIEEE #5302): The authors of a previously published paper on the dependence of electromagnetic (EM) energy absorption concluded that homogeneous modeling of the human head is suited for assessing the spatial-peak absorption for transmitters operating at 900 MHz or below. Additional studies became necessary for the frequency bands utilized by new mobile communications systems (i.e., 1.5 and 2.5 GHz) since some peripheral tissue layers have a thickness of the range of lamda/4lamda/2. The results of the simulations combined with worst-case considerations confirmed the anticipated and more complex relationship between absorption and anatomical details at these higher frequencies. Nevertheless, a homogeneous representation of the head is suited for assessing the maximum specific absorption rate (SAR) in the head of the user of mobile telecommunication equipment (MTE) if the appropriate dielectric parameters are chosen. AUTHORS' ABSTRACT: Li, Douglas, Kuster et al. 2011 (IEEE #6059): This study is an investigation of the influence of the user's hand on the radiated performance of a mobile phone, particularly the peak spatial averaged Specific Absorption Rate (psSAR) averaged over 1 g and 10 g in the head of the user. Recent studies found that the psSAR in the head can be increased by the presence of the hand in some cases. In this study, simulations are performed at 900 and 1800 MHz on different mobile phone models, and the psSAR in the head is recorded with and without a hand holding the mobile phone. Numerical simulations were conducted on four mobile phone models, and hand models were posed in different locations and grips to find the condition with the highest psSAR. Simulations show that the psSAR with the hand can be up to about 2.5 dB higher than without the hand. The psSAR is sensitive to the hand grip, with more than 3 dB variation possible, depending on the hand location and palm distance.
Findings		Not Applicable to Bioeffects
Status		Completed With Publication
Principal Investigator		IT'IS, Switzerland - kuster@itis.ethz.ch
Funding Agency		EU, Swiss Telecom, BfS, Germany, MMF, Nat'l Res Prog, Switzerland (SNSF, NRP57), DMF, Germany
Country		SWITZERLAND
References		Christ , A et al. Bioelectromagnetics., (2004) 26:125-137 Kuster , N et al. Bioelectromagnitics, (2004) 25:524- Hombach, V et al. IEEE Trans Microwave Theory Tech., (1996) 44:1865-1873 Schonborn, F et al. Health Physics, (1998) 74:160-168 Burkhardt, M et al. Health Physics, (1997) 73:770-778 Christ, A et al. Bioelectromagnetics, (2010) 31:406-412 Li , CH et al. IEEE Transactions on Antennnas and Propagation. , (2012) 60:1066-1074 Li , CH et al. IEEE Transactions on Microwave Theory and Techniques. , (2012) 60:2267-2276 Gosselin , MC et al. IEICE Transactions on Communication. , (2012) E95-B:3215-3224 Meier, K et al. IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES., (1997) 45:2058-2062 Li, CH et al. IEEE International Symposium on Antennas and Propagation (APSURSI)., (2011) :141-144 Neufeld, E et al. Front Physiol., (2018) 9:1594:doi: 10.3389/fphys.2018.01594-
Comments