Focusing applicator for SoFT: thermal therapy using fibres

摘要

A method of focusing ultrasound radiated from an applicator in the shape of a rod is described. Since the ultrasonic wave radiated into the water is in the shape of a cone, the ultrasonic wave is focused using a semiparabolic mirror. The focusing effect was confirmed experimentally. In an attempt to develop a new method for interstitial therapy, we have been developing a method to transmit high-intensity ultrasound generated with the large transducer outside of the human body using a flexible transmission line, and to transmit it from the transmission line to tissues [1,2]. We named this method SoFT, a thermal therapy using fibres as transmission lines. We have developed the ability to transmit ultrasound from the transmission line to tissues without using a matching layer, using an applicator in the shape of a capsule connected to the flexible fibre. Although the conversion efficiency from the applicator to tissue was as high as 90%, the ultrasound was not focused.