Finite-difference time-domain modeling with bioelectromagnetic applications

Abstract

The Finite-Difference Time-Domain method has become one of the methods of choice for modeling electromagnetic interactions with biological structures. Finite-Difference Time-Domain codes can model complex geometrical structures; they can easily incorporate dispersion, non-linearities, and other complex phenomena; and they can provide information about transients and pulses which can, combined with Fast Fourier Transforms and other simple techniques, provide valuable spectral information. This thesis applied Finite-Difference Time-Domain methods to several bioelectromagnetic situations. A human head, modeled as two-dimensional layered dielectric cylinders, is heated using TE and TM polarizations. Magnetic shielding is demonstrated through the introduction of magnetic properties into the Finite-Difference Time-Domain codes. Dielectric and magnetic properties are combined to examine the resonances that can occur when electromagnetic fields scatter off magnetic particles embedded within biological cells. Finally, dispersion methods are suggested for modelling the physical properties of magnetite, a naturally occurring magnetic material found in many living systems.