The increasing exposure of man to radio frequency energy has necessitated obtaining dosimetric information for use in the evaluation of possible biological hazards. Though of great significance, previous dosimetric work has mostly focused on the whole-body absorption for various exposure conditions. Except on a very gross basis (180-cell representation of man), knowledge is quite inadequate on the distribution of the absorbed electromagnetic energy (SAR) which is considered important for the assessment of biological effects. On the current project we have developed a new, numerically efficient, fast-Fourier-transform (FFT) method which may be extendable for determination of local SARs in 10,000 to 100,000 cells. Also developed is an inhomogeneous thermal block model of man capable of using the SAR distributions to give detailed temperature variations within the body. The proposed work will extend the FFT method, tested to date for two-dimensional bodies, to three-dimensional models of man to calculate the SARs for the crucial regions such as the eyes, the gonads, parts of the CNS, etc. Also proposed are some needed improvements in the thermal model to incorporate a skin layer, clothing, and a more detailed vascular system and extension of the model for higher and lower ambient temperatures. It is proposed to test the validity of the FFT and thermal models by developing the corresponding models of a rat and experimental determination of SAR and temperature distributions.
Sullivan, D M; Gandhi, O P; Taflove, A (1988) Use of the finite-difference time-domain method for calculating EM absorption in man models. IEEE Trans Biomed Eng 35:179-86 |
Sullivan, D M; Borup, D T; Gandhi, O P (1987) Use of the finite-difference time-domain method in calculating EM absorption in human tissues. IEEE Trans Biomed Eng 34:148-57 |