Phased array design for near field focused hyperthermia based on reciprocity theorem

Abstract

The estimation of the proper amplitude and phase excitation of phased array applicator used for hyperthermia treatment constitutes the scope of this work. The aim of this array is to focus the electromagnetic power only on the malignant biological tissues and not to create other unwanted secondary “hot spots”. The proposed method is based on the reciprocity theorem in order to build the simulation model for the exact numerical calculation of the excitation values. Explicitly, a simplistic body model or Human arm is constructed including the antennas and the water bolus utilized for cooling. An antenna is placed at the tumor center acting as source and an electromagnetic simulation is performed to estimate the path delay (phase difference) to each array element. These delays or phase differences are used to define the array excitation currents, ensuring the focus of the electromagnetic power on the tumors.