Applicability of Homogeneous Human Trunk Phantom in Estimating the Radiation Characteristics of Body-worn Devices

In this paper, the radiation characteristics with respect to the suitability of using homogeneous phantom for testing the compliance of radiation frequency devices are assessed. The Finite-Difference Time-Domain (FDTD) method is applied to analyze the variations of a 900 MHz half-wavelength dipole antenna's biological effects and link performance depending on distance between antenna and human body model. The distance between the surface of the model and the outside exposure source is changed from 25 mm to 1 mm within the range of λ/2π. The distributions of the specific absorption rates (SARs) and the electric fields for various vertical slices of a simplified homogeneous phantom and three anatomical human body trunk models are calculated, respectively. The legs and head have little influence on the radiation characteristics of body-worn, ingestible or implantable wireless devices. The results demonstrate that a homogenous representation of human body is suited for assessing the averaged SARs in human body and confirm that the local energy absorption details and communication link performance need to be analyzed by using the anatomical models or by combining with the worst-case consideration.

[1]  Charles Polk,et al.  CRC Handbook of Biological Effects of Electromagnetic Fields , 1986 .

[2]  N. Kuster,et al.  Energy absorption mechanism by biological bodies in the near field of dipole antennas above 300 MHz , 1992 .

[3]  R. Luebbers,et al.  The Finite Difference Time Domain Method for Electromagnetics , 1993 .

[4]  J. Bérenger.  Three-Dimensional Perfectly Matched Layer for the Absorption of Electromagnetic Waves , 1996 .

[5]  R. W. Lau,et al.  The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues. , 1996, Physics in medicine and biology.

[6]  N. Kuster,et al.  Dipole configurations with strongly improved radiation efficiency for hand-held transceivers , 1998 .

[7]  G. Iddan,et al.  Wireless capsule endoscopy , 2003, Gut.

[8]  Koichi Ito,et al.  Development and characteristics of a biological tissue‐equivalent phantom for microwaves , 2001 .

[9]  J. M. Osepchuk,et al.  Safety standards for exposure to RF electromagnetic fields , 2001 .

[10]  O. Gandhi,et al.  Some present problems and a proposed experimental phantom for SAR compliance testing of cellular telephones at 835 and 1900 MHz. , 2002, Physics in medicine and biology.

[11]  Dragan Poljak.  Human Exposure to Electromagnetic Fields , 2003 .

[12]  P. Irazoqui-Pastor,et al.  In-vivo EEG recording using a wireless implantable neural transceiver , 2003, First International IEEE EMBS Conference on Neural Engineering, 2003. Conference Proceedings..

[13]  Tuukka Lehtiniemi,et al.  On the General Energy-Absorption Mechanism in the Human Tissue , 2004 .

[14]  U. Kawoos,et al.  A permanently implantable intracranial pressure monitor , 2005, Proceedings of the IEEE 31st Annual Northeast Bioengineering Conference, 2005..

[15]  D. Brooks,et al.  Analysis of phantom boundary shell and the resultant matching effect of shell on SAR (specific absorption rate) values , 2005, 2005 International Symposium on Electromagnetic Compatibility, 2005. EMC 2005..

[16]  Koichi Ogawa,et al.  Attenuation Characteristics of the SAR in a COST244 Phantom with Different EM Source Locations and Sizes , 2005, IEICE Trans. Commun..

[17]  H. Usui,et al.  Radiation characteristics of an implanted cavity slot antenna into the human body , 2006, 2006 IEEE Antennas and Propagation Society International Symposium.

[18]  D. Werber,et al.  Investigation of RF transmission properties of human tissues , 2006 .

[19]  T. Samaras,et al.  The dependence of electromagnetic far-field absorption on body tissue composition in the frequency range from 300 MHz to 6 GHz , 2006, IEEE Transactions on Microwave Theory and Techniques.

[20]  A. Faraone,et al.  Comparisons of computed mobile phone induced SAR in the SAM phantom to that in anatomically correct models of the human head , 2006, IEEE Transactions on Electromagnetic Compatibility.

[21]  Jin-Ho Cho,et al.  CPLD Based Bi-Directional Wireless Capsule Endoscopes , 2007, IEICE Trans. Inf. Syst..