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Theoretical and experimental determination of SAR patterns for spherical tissue models in a rectangular resonant cavity
Author(s) -
Yang GenYuan,
Chou ChungKwang,
Guy Arthur W.
Publication year - 1984
Publication title -
bioelectromagnetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.435
H-Index - 81
eISSN - 1521-186X
pISSN - 0197-8462
DOI - 10.1002/bem.2250050110
Subject(s) - superposition principle , radius , spheres , specific absorption rate , absorption (acoustics) , conductivity , computational physics , plane (geometry) , physics , plane wave , optics , excited state , electrical resistivity and conductivity , scaling , molecular physics , materials science , atomic physics , geometry , mathematics , antenna (radio) , quantum mechanics , telecommunications , computer security , astronomy , computer science
Specific absorption rates (SARs) were determined theoretically and experimentally for several spherical models of tissue exposed to electrical fields of TE 101 mode in a rectangular cavity of 57.3 MHz resonant frequency. The approximate theoretical SAR can be calculated according to the Mie theory by superposition of four plane waves representing the fields excited in the cavity. The theoretical and thermographically determined SAR patterns in spheres with radii of 5, 7.5, and 10 cm and with conductivities of 0.1, 1, and 10 S/m were compared. For a sphere with radius less than 7.5 cm and conductivity less than 1 S/m, the SAR was quite uniform. When conductivity was increased to 10 S/m, the SAR patterns showed higher absorption in the periphery of the largest sphere (10‐cm radius). These characteristics are important in evaluating the scaling technique of exposing a model of a human to very‐high‐frequency fields to obtain power absorption data in humans exposed to high‐frequency or very‐low‐frequency fields.