Novel Preprocessing Techniques for Accurate Microwave Imaging of Human Brain

Two novel preprocessing techniques are applied to reinforce the detection performance and the image quality in microwave imaging systems designed for brain stroke detection. The image of energy distribution is obtained by applying a delay-and-sum beamforming to the backscattered signals measured using a hemielliptical array of 16 corrugated tapered slot antenna elements surrounding the head. The beamformer forms a spatially filtered combination of time-delayed response of scattering points in the head exposed to microwave radiation over the band from 1 to 4 GHz. The proposed techniques are validated on a realistic head phantom that is fabricated to emulate the electrical properties of real human head. The results show how the proposed techniques enable the detection and localization of hemorrhagic stroke accurately.