Abstract
High-intensity focused ultrasound (HIFU) is widely used for therapeutic applications because it is an attractive and non-invasive tool by which to provide thermal therapy. Focus position control of HIFU using multi-elements phase control is very popular in clinical application. However, multi-elements driving amplifier are very large size like a large refrigerator. So, we adopted a direct drive amplifier system for the multi-element transducer. This system has an advantage that it reduces the energy loss of the connecting cable between the transducer element and the amplifier. So, we make the very compact multi-elements transducer system combined with multi-elements amplifier. In this study, we evaluated the specification and system design of the first prototype module transducer. We discussed the requirement of the specification. We already decided an element gap, a number of elements and a beam steering angle. So, we set the various element pitches with a numerical simulation. The evaluation used the ratio of the beam density of the first peak and the second peak. About the optimized conditions, the peak ratio of the beam is less than 50% and the element pitch becomes the maximum length. As a result, the pitch 2mm is the best length for this transducer design with the numerical simulation.
