1-2hit |
Osamu FUJIWARA Michihiko NOMURA
Correlation between the surface-SAR and external magnetic near-field in a realistic head model for 1.5GHz microwave far-field exposure is described. The regression relation is shown between the one gram averaged SAR and squared external magnetic field on the cross sectional perimeter of the head model.
Osamu FUJIWARA Michihiko NOMURA
A method is described for approximately estimating the surface specific-absorption-rate (SAR) in an anatomically realistic model of the human head for microwave exposure using the external magnetic near-field. The finite-difference time-domain (FD-TD) technique is used to compute the electromagnetic fields in the head model for 750-MHz and 1.5-GHz far-field exposures with the 1991 ANSI specified safety level. The spatial pattern tracking between the one-gram averaged surface-SAR and external magnetic near-field is demonstrated on the horizontal cross sectional perimeter of the head model. The regression coefficients between them are also obtained on the fifty-five horizontal cross sectional perimeters, which could give an approximate value of the surface-SAR in an acutual head, if the external magnetic near-field would be measured. This is validated by the theoretical results in a semi-infinite homogeneous flat model for normal incidence microwave exposure.