Electrodynamics of microwave near-field probing: Application to medical diagnostics

A theory for the near-field (NF) microwave diagnostics of planar-stratified media is developed based on the design of an equivalent NF probe circuit and the solution of the electrodynamical problem for the electromagnetic field of antenna in an inhomogeneous ambient medium. The theory has been verified experimentally by probing into water with controllable dielectric permittivity. A theoretical and experimental study into a possibility to locate contrast structures (malignant growths) within biological media by means of NF probing has been carried out. Detectable contrasts of a growth have been calculated depending on its dimensions and depth of occurrence. Two-dimensional images of a tumorlike contrast object have been obtained for different depths of the object submersion in water. A measurement technique reducing the masking effect of background fluctuations arising by probe contact with a pliant surface is proposed.