Radio Frequency Dosimetry at the Air Force Research Laboratory

Abstract

Abstract : Knowledge of internal E- and H-fields, induced current densities, and SARs is of basic interest in the assessment of biological effects and medical applications of electromagnetic fields. Dosimetry is an important part of any scientific effort to assess the effects of EMF on biological organisms. Experimental dosimetry is essential in determining the internal fields and the whole body or localized SAR values in experiments with phantoms or animals. Carefully performed experiments are crucial in verification of theoretical predictions. In the last few years, considerable progress has been achieved in experimental and numerical dosimetry. Today a broad range of tools for dosimetric analysis for the wide frequency range is available. Because of the heterogeneity of the tissues and the nonuniformity of the incident fields, closed form analytical solutions are impossible and computer methods are needed to obtain the internally coupled fields. In theoretical dosimetry, FDTD is currently the most acceptable choice if digital anatomical models of man and animals are to be analyzed. The main contribution of our research efforts to the discipline of theoretical dosimetry is identification of the dependence of predicted SAR in relation to the variability in permittivity values for different tissue types when using different numerical anatomical models.