Detection of contrast objects inside biological media by near-field microwave diagnostics

Theoretical and experimental investigations demonstrate the prospects of near-field microwave location of malignant tumors in biological tissue. The theoretical analysis is performed in terms of the theory of near-field location developed for layered structures. The experimental verification of the theory is accomplished by sounding an aqueous medium with a controllable permittivity. The tumor contrast is calculated based on the ideas of the dielectric properties of healthy and affected human tissues. The reason for and the degree of background contrasts as applied to near-field measurements are studied experimentally. An optimal measuring scheme for minimizing the masking effect of background contrasts is proposed. The 2D images of a tumor-simulating contrast object immersed in the aqueous medium at different depths are obtained. The prospects of near-field diagnostics for subsurface temperature measurement are discussed.