Modeling with the FDTD method for microwave breast cancer detection

This paper addresses important issues related to finite-difference time-domain modeling for microwave breast cancer detection. We present a simple and efficient way of modeling dispersion for various types of biological tissue, in the range of 30 MHz-20 GHz. Propagation and absorbing boundary conditions are modified accordingly. Results from three-dimensional simulations of a semiellipsoid geometric representation of the breast terminated by a planar chest wall illustrate the effect of certain important aspects of the detection problem including: 1) the pulse distorting effects of propagation in frequency-dependent tissue; 2) the choice of the surrounding medium; and 3) the transmitter location relative to the breast and chest wall. In particular, it is shown that the presence of the chest wall can affect greatly the system´s detection abilities, even for tumors that are not located in the proximity of the chest wall.