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Progress In Electromagnetics Research B
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EFFECTIVE RESISTANCE OF GROUNDED HUMANS FOR WHOLE-BODY AVERAGED SAR ESTIMATION AT RESONANCE FREQUENCIES

By K. Yanase and A. Hirata

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Abstract:
Whole-body averaged specific absorption rate (WBA-SAR) is used as a metric for human protection from whole-body exposures. The frequency at which the WBA-SAR becomes maximal is called ``resonance frequency''. The present study proposes a scheme to estimate WBA-SAR at the resonance frequency based on an analogy between a human and a quarter-wavelength monopole antenna. Specifically, WBA-SAR can be estimated with the human body resistance once ankle current was obtained. Thus, it is essential to investigate the effective resistance for anatomically-based human models. Then, the effective resistances for different humans grounded on the perfect conductor are calculated to clarify the variability. The main factors for the variability were attributed to the body shape and model anatomy. In particular, WBA-SARs in human models grounded are found to be estimated from their BMI and respective measured ankle current in realistic environment, including a scenario of multiple wave exposure.

Citation:
K. Yanase and A. Hirata, "Effective Resistance of Grounded Humans for Whole-Body Averaged SAR Estimation at Resonance Frequencies," Progress In Electromagnetics Research B, Vol. 35, 15-27, 2011.
doi:10.2528/PIERB11082511

References:
1. ICNIRP (International Commission on Non-Ionizing Radiation Protection), "Guideline for limiting exposure to time-varying electric, magnetic, and electromagnetic fields (up to 300 GHz)," Health Phys., Vol. 74, 494-522, 1998.

2., IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Field, 3 kHz to 300 GHz (C95.1), 2005.

3. Sabbah, A. I., N. I. Dib, and M. A. Al-Nimr, "SAR and temperature elevation in a multi-layered human head model due to an obliquely incident plane wave," Progress In Electromagnetics Research M, Vol. 13, 95-108, 2010.
doi:10.2528/PIERM10051502

4. Omar, A. A., "Complex image solution of SAR inside a human head illuminated by a finite-length dipole," Progress In Electromagnetics Research B, Vol. 24, 223-239, 2010.
doi:10.2528/PIERB10062604

5. Liu, Y., Z. Liang, and Z. Yang, "Computation of electromagnetic dosimetry for human body using parallel FDTD algorithm combined with interpolation technique," Progress In Electromagnetic Research, Vol. 82, 95-107, 2008.
doi:10.2528/PIER08021603

6. Mohsin, S. A., N. M. Sheikh, and U. Saeed, "MRI induced heating of deep brain stimulation leads: Effect of the air-tissue interface," Progress In Electromagnetics Research, Vol. 83, 81-91, 2008.
doi:10.2528/PIER08040504

7. Lopez-Martin, E., J. C. Bregains, F. J. Jorge-Barreiro, J. L. Sebastián-Franco, E. Moreno-Piquero, and F. Ares-Pena, "An experimental set-up for measurement of the power absorbed from 900MHz GSM standing waves by small animals, illustrated by application to picrotoxin-treated rats," Progress In Electromagnetics Research, Vol. 87, 149-165, 2008.
doi:10.2528/PIER08101307

8. Hirata, A., H. Sugiyama, and O. Fujiwara, "Estimation of core temperature elevation in humans and animals for whole-body averaged SAR," Progress In Electromagnetics Research, Vol. 99, 53-70, 2009.
doi:10.2528/PIER09101603

9. Korniewicz, H., "The first resonance of arounded human being exposed to electric field," IEEE Trans. Electromagnet. Compat., Vol. 37, No. 2, 296-299, 1995.
doi:10.1109/15.385898

10. Durney, C. H., "Electromagnetic dosimetry for models of humans and animals: A review of theoretical and numerical techniques," Proc. IEEE, Vol. 68, 33-40, 1980.
doi:10.1109/PROC.1980.11578

11. Gandhi, O. P., "State of knowledge for electromagnetic absorbed dose in man and animals," Proc. IEEE, Vol. 68, 24-32, 1980.
doi:10.1109/PROC.1980.11577

12. Dimbylow, P. J., "FDTD calculations of the whole-body average SAR in an anatomically realistic voxel model of the human body from 1MHz to 1 GHz," Phys. Med. Biol., Vol. 42, 479-490, 1997.
doi:10.1088/0031-9155/42/3/003

13. Dimbylow, P. J., "Fine resolution calculation s of SAR in the human body for frequencies up to 3 GHz," Phys. Med. Biol., Vol. 47, 2835-2846, 2002.
doi:10.1088/0031-9155/47/16/301

14. Wang, J., S. Kodera, O. Fujiwara, and S. Watanabe, "FDTD calculation of whole-body average SAR in adult and child models for frequencies from 30MHz to 3 GHz," Phys. Med. Biol., Vol. 51, 4119-4127, 2006.
doi:10.1088/0031-9155/51/17/001

15. Dimbylow, P., "Resonance behavior of whole-body average specific absorption rate (SAR) in the female voxel models, NAOMI," Phys. Med. Biol., Vol. 50, 4053-4063, 2005.
doi:10.1088/0031-9155/50/17/009

16. Conil, E., A. Hadjem, F. Lacroux, M. F. Wong, and J. Wiart, "Variability analysis of SAR from 20MHz to 2.4 GHz for different adult and child models using finite-difference time-domain," Phys. Med. Biol., Vol. 53, 1511-1525, 2008.
doi:10.1088/0031-9155/53/6/001

17. Dimbylow, P. and W. Bolch, "Whole-body-averaged SAR from 50MHz to 4 GHz in the University of Florida child voxel phantoms," Phys. Med. Biol., Vol. 52, 6639-6649, 2007.
doi:10.1088/0031-9155/52/22/006

18. Hirata, A., K. Yanase, O. Fujiwara, A. Y. Simba, T. Arima, and S. Watanabe, Estimation of whole-body averaged SAR of grounded human at resonance frequency from ankle current of simplified phantom, Proc. EMC Europe, O_Tu_D1, 2011.

19. Zhang, M. and A. Alden, "Calculation of whole-body SAR from a 100MHz dipole antenna," Progress In Electromagnetics Research, Vol. 119, 133-153, 2011.
doi:10.2528/PIER11052005

20. Takahashi, Y., T. Arima, P. Pongpaibool, S. Watanabe, and T. Uno, Development of a liquid-type human-body equivalent antenna using NaCl solution, Int'l Zurich Symp. Electromagnet. Compat., BIO2-5, Sep. 2007.

21. Nagaoka, T., S. Watanabe, K. Sakurai, E. Kunieda, S. Watanabe, M. Taki, and Y. Yamanaka, "Development of realistic high-resolution whole-body voxel models of Japanese adult males and females of average height and weight, and application of models to radio-frequency electromagnetic-field dosimetry," Phys. Med. Biol., Vol. 49, 1-15, 2004.
doi:10.1088/0031-9155/49/1/001

22. Nagaoka, T., E. Kunieda, and S. Watanabe, "Proportion-corrected scaled voxel models for Japanese children and their application to the numerical dosimetry of specific absorption rate for frequencies from 30MHz to 3 GHz," Phys. Med. Biol., Vol. 52, 6695-6711, 2008.
doi:10.1088/0031-9155/53/23/004

23. Nagaoka, T., T. Togashi, K. Saito, M. Takahashi, K. Ito, and S. Watanabe, "An anatomically realistic whole-body pregnant-woman model and specific absorption rates for pregnant-woman exposure to electromagnetic plane waves from 10MHz to 2 GHz," Phys. Med. Biol., Vol. 52, 6731-6745, 6731.
doi:10.1088/0031-9155/52/22/012

24. Mason, P. A., W. D. Hurt, T. J. Walter, A. D'Amdrea, P. Gajsek, K. L. Ryan, D. A. Nelson, K I. Smith, and J. M. Ziriax, "Effects of frequency, permittivity and voxel size on predicted specific absorption rate values in biological tissue during electromagnetic-field exposure," IEEE Trans. Microwave Theory Tech., Vol. 48, No. 11, 2050-2058, 2000.
doi:10.1109/22.884202

25. Christ, A., W. Kainz, E. G. Hahn, K. Honegger, M. Zefferer, E. Neufeld, W. Rascher, R. Janka, W. Bautz, J. Chen, B. Keifer, P. Schmit, H. P. Hollenbach, J. Shen, M. Oberle, D. Szczerba, A. Kam, J. W. Guag, and N. Kuster, "The Virtual Family --- development of surface --- based on anatomical methods of two adults and two children for dosimetric simulations," Phys. Med. Biol., Vol. 55, 22-38, 2010.

26. Taflove, A. and S. Hagness, Computational Electrodynamics: The Finite-difference Time-domain Method, 3rd Ed., Artech House Publishers, Norwood, MA, 2003.

27. Dimbylow, P. J., A. Hirata, and T. Nagaoka, "Intercomparison of whole-body averaged SAR in European and Japanese voxel phantom," Phys. Med. Biol., Vol. 53, 5883-5898, 2008.
doi:10.1088/0031-9155/53/20/022

28. Gabriel, C., "Compilation of the dielectric properties of body tissues at RF and microwave frequencies," Brooks Air Force Technical Report, AL/OE-TR-1996-0037, 1996.

29. Penman, A. D. and W. D. Johnson, "The changing shape of the body mass index distribution curve in the population: Implications for public health policy to reduce the prevalence of adult obesity," Prev. Chronic Dis., Vol. 3, No. 3, A74, 2006.

30. Conil, E., A. Hadjem, A. El Habachi, and J. Wiart, "Whole body exposure at 2100MHz induced by plane wave of random incidences in a population," Comptes Redus Phs., Vol. 11, 531-540, 2010.
doi:10.1016/j.crhy.2010.11.007

31. Conil, E., A. Hadjem, A. Gati, M.-F. Wong, and J. Wiart, "Influence of plane-wave incidence angle on whole body and local exposure at 2100 MHz," IEEE Trans. Electromagnet. Compat., Vol. 53, No. 1, 48-52, 2011.
doi:10.1109/TEMC.2010.2061849

32. Hirata, A., H. Watanabe, and T. Shiozawa, "SAR and temperature rise in the human eye induced by obliquely incident plane waves," IEEE Trans. Electromagnet. Compat., Vol. 44, No. 4, 594-596, Nov. 2002.


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