The use of the frequency-dependent finite-difference time-domain method for induced current and SAR calculations for a heterogeneous model of the human body

This paper describes the use of the previously formulated frequency-dependent finite-difference time-domain ((FD)²TD) method for analysis of an anatomically based heterogeneous man model exposed to ultra-wide-band electromagnetic pulse sources. The human tissues´ electrical permittivities, ε_i*(ω) are described by Debye equations with two relaxation constants, and the equation D(t)=ε*(ω))E(t) is converted to a finite-difference equation along with the Maxwell´s equations used by the standard FDTD method. Using a single run with a broad-band pulse excitation, the (FD) ²TD method is used to calculate mass normalized rates of energy deposition (specific absorption rates or SARs) and induced currents in the man model over a broad band of frequencies. Time-domain coupling of a representative ultrashort pulse of subnanosecond rise time and nanosecond pulse duration to the human body is also examined