Blind Focusing in Microwave Hyperthermia by Target Contrast Variation

The paper suggests a novel blind focusing approach for microwave hyperthermia. The idea is to exploit a contrast variation induced in the diseased tissue for the synthesis of the excitations of the antenna array employed for the field focusing, by performing a differential scattering measurement. In particular, the excitation vector is set as the right singular vector associated to the largest singular value of the differential scattering data matrix, obtained as the difference of the scattering matrixes measured, by the antenna array itself, before and after the contrast change. The approach is computationally effective and totally blind, not requiring any a priori knowledge on the electric and geometric features of the region hosting the target and on its spatial location with respect to the antenna array.