A FEM simulation study of the optimization of the imaging attributes of a microwave radiometry system with possible functional imaging capabilities

Abstract

Microwave radiometry is a measurement technique which detects natural-thermal radiation emitted by matter. The human brain having certain temperature and specific electromagnetic properties emits chaotic radiation throughout the whole electromagnetic spectrum. A novel Microwave Radiometry Imaging System (MiRaIS) comprising an ellipsoidal conductive wall cavity and sensitive radiometric receivers, operating at low microwave frequencies (1-4GHz), has been used the past four years in various experiments to assess its value as a potential intracranial imaging device. With this view, current research aims at the improvement of the system's focusing properties using matching layers made of dielectric and left handed materials that are placed around a double layered human head model. Another approach tested, included filling of the whole ellipsoidal with a lossless dielectric material in conjunction with reduction of the ellipsoid's volume. The results show better focusing properties in the brain areas of interest and improvement of the system's spatial resolution. Future research including mainly phantom and human experiments implementing the above ideas will illustrate the value of the present simulation study.