Noninvasive recovery of skin thickness and its dielectric properties in the microwave range: a two-dimensional time-domain inverse-scattering algorithm

Motivated by the need to calibrate the recently proposed microwave breast tumor detection system, we present results of development of a two-dimensional time-domain inverse-scattering algorithm for determining skin thickness, and relative permittivity /spl epsiv//sub r-skin/ and electric conductivity /spl sigma//sub skin/ in the microwave range. The algorithm traces a search trajectory in the (/spl epsiv//sub r-skin/, /spl sigma//sub skin/) space. The minimal parameter estimation error along this trajectory yields a set of correct parameter values. These results of the inverse-scattering technique depend on the shape and the duration of the pulse chosen for the electrical parameter reconstruction. The time-domain nature of the inverse-algorithm allows for limiting the region of inversion. Thus, when the parameters of the skin are estimated, the skin thickness can be determined by comparing the measurement with a simulated all-skin response.