用於肝臟腫瘤治療之曲面圓柱型超音波相位陣列換能器

Abstract

This study is to design a novel curved cylindrical ultrasound phased array for liver tumor therapy in ultrasound hyperthermia, and we attempt to track and treat the liver tumor by controlling the focus in 3-dimension.The goal of the study is to design the geometric configuration of the phased array, the focus-steering ability of the phase array, the thermal effect by the phased array and its application to liver tumor therapy. We showed the ability of steering the focus of the curved cylindrical phased array is good in 2-dimension in a finite range. The sound intensity level, thermal effects and half-power beamwidth is suitable for liver tumor therapy. When compared with the cylindrical phased array, the curved cylindrical phased array is better in its sound intensity and the total effective power in the field. We also proved the feasibility of using pseudo-inverse method for focus-steering simulating in multi-layered environment. The first chapter is to introduce the ultrasound hyperthermia and its difficulties in treating the liver. The second chapter is to discuss the basic theorems and physical meaning of the acoustics and the ultrasound hyperthermia. The third chapter is to show the results for the curved cylindrical phased array simulation, including the focus-steering ability, the pattern of the natural focus, the thermal effects, simulation results in multi-layer environment, and the comparison between the curved cylindrical phased array and the cylindrical phased array. The last chapter is to sum up and discuss the results of the study.