Various diffraction effects and their importance for detection of inhomogeneites in human tissues

Abstract

Hitherto described microwave modalities for detection of internal inhomogeneities in human tissues such as breasts and heads are by image reconstruction, requiring time-consuming computational resources. The method developed at MDH is instead based on the use of a magnetic field transducer, creating an essentially circular electrical field. This is in turn diffracted by the dielectric inhomogenity and that signal is received by an E-field sensor in an appropriate position. The transmitting applicator is unique by no need to contact the object under study (OUS) and does not generate any surface waves at it. The primary field has properties behaving as coming from a magnetic monopole. The receiving 3D contacting applicator contains a high-permittivity ceramic and is resonant in order to provide the desired field polarisation sensitivity. The desired system properties are achieved by optimized use of the orthogonality properties of the primary magnetic, induced electric, and diffracted electric fields. Key words: Diffraction, magnetic field, applicator, internal inhomogeneity.