Quantification and Verification of Whole-Body-Average SARs in Small Animals Exposed to Electromagnetic Fields inside Reverberation Chamber

Jingjing SHI  Jerdvisanop CHAKAROTHAI  Jianqing WANG  Kanako WAKE  Soichi WATANABE  Osamu FUJIWARA  

IEICE TRANSACTIONS on Communications   Vol.E97-B   No.10   pp.2184-2191
Publication Date: 2014/10/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E97.B.2184
Type of Manuscript: PAPER
Category: Electromagnetic Compatibility(EMC)
specific absorption rate (SAR),  reverberation-chamber (RC),  exposure system,  finite-difference time-domain (FDTD) method,  method of moments (MoM),  

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This paper aims to achieve a high-quality exposure level quantification of whole-body average-specific absorption rates (WBA-SARs) for small animals in a medium-size reverberation chamber (RC). A two-step method, which incorporates the finite-difference time-domain (FDTD) numerical solutions with electric field measurements in an RC-type exposure system, has been used as an evaluation method to determine the whole-body exposure level in small animals. However, there is little data that quantitatively demonstrate the validity and accuracy of this method in an RC up to now. In order to clarify the validity of the two-step method, we compare the physical quantities in terms of electric field strength and WBA-SARs by using a direct numerical assessment method known as the method of moments (MoM) with ten homogenous gel phantoms placed in an RC with 2GHz exposure. The comparison results show that the relative errors between the two-step method and the MoM approach are approximately below 10%, which reveals the validity and usefulness of the two-step technique. Finally, we perform a dosimetric analysis of the WBA-SARs for anatomical mouse models with the two-step method and determine the input power related to our developed RC-exposure system to achieve a target exposure level in small animals.