P5J-3 Design of a Piezocomposite Matrix Transducer Configuration for Multi-Mode Operation in HIFU Applications

High Intensity Focused Ultrasound (HIFU) is now a recognized method for the non-invasive treatment of tumors, and transducers are required to have more and more capabilities. The most advanced HIFU transducers can produce enough power for thermal ablation and can also electronically steer and focus the power ultrasonic beam to create a defined volume necrosis using 2D transducer arrays. In addition, the formation of the necrosis must be controlled by monitoring the treatment through an appropriate imaging method, usually either external ultrasound imaging (UI) or magnetic resonance imaging (MRI). The proposed design, based on power piezocomposite technology, combines UI and HIFU capabilities with the same active area. To achieve this goal, the electro-acoustic structure is optimized, as well as the acoustical and electrical matching of the transducer elements. The 2D structure of the array is designed to allow both the electronic driving of the HIFU focal point into a volume and also the monitoring of the treatment through the imaging of the area of interest around the necrosis. Additional functions such as tracking the movements made during the treatment can also be carried out with elements of the array. The MRI compatibility of the whole transducer can be achieved by the right choice of materials, making the simultaneous control by MRI and UI possible. It is expected that this multi-mode matrix type of transducer has good potential for both external and endocavitary HIFU applications.