Theoretical Comparison of TLM and Hybridization of MoM and GMT for the Numerical Analysis of the Electromagnetic Field Inside the Biological Bodies

摘要

The problem of determining electromagnetic fields (EMF), absorbed power density (APD), and specific absorption rate (SAR) inside arbitrarily shaped biological bodies is considered. The biological bodies are assumed as the human body or human brain illuminated by a plane wave, and EMF, APD, and SAR are calculated inside the biological bodies. The EMF, APD, and SAR theoretical derivation inside the biological bodies by a three-dimensional transmission line matrix (TLM) method with asymmetrical condensed node is given. The combination of the method of moment (MoM) and generalized multipole technique (GMT) is used to determine the field inside the biological bodies. A complete dispersion analysis is given for the TLM and combination of MoM and GMT. In TLM, wave amplitudes inside electric and magnetic field components represent the electromagnetic field. The correct mapping between the wave amplitudes and field components is described by the cell boundary mapping. The combination of MoM and GMT method is based on domain integral representation of the field inside the body. Both methods involve an iterative minimization of the defect between the number of cells and the field calculated by integral representation. The two algorithms are compared. The methods employed the same initial guess and a priori information that the characteristic function is nonnegative.