Modeling Human Head at Microwave Frequencies Using Optimized Debye Models and FDTD Method

Debye models for tissues found in the human head are presented. The parameters of the Debye models are optimized to measured data of different head tissues. Excellent consistency over the frequency band from 0.1 GHz to 5 GHz is shown with improved accuracy compared to current models using the Cole-Cole approximation. The auxiliary differential-equation based method is used to incorporate the derived models into a finite-difference time-domain program. The validity of the derived models are verified by comparing the fields produced in a realistic 2-D phantom head using a finite-difference time-domain program with the proposed Debye models, and a method of moments solver.