Coded excitation technique for real-time simultaneous HIFU therapy and imaging

Real-time simultaneous high intensity focused ultrasound (HIFU) therapy and imaging allows for tracking tissue movement and monitoring feedback from a treated target. In ultrasound image guided HIFU using an integrated HIFU/imaging transducer, the reflected strong HIFU interference received by the imaging transducer degraded imaging quality. In order to figure out this problem, we have previously proposed a coded excitation technique combined with a notch filter to minimize HIFU interference, and demonstrated its feasibility using Field-II and commercial imaging transducers based on numerical calculation. In this study, we made a prototype integrated HIFU/imaging transducer and experimentally verified the performance of the coded excitation method with notch filtering. A-mode and B-mode in vitro test were conducted and showed that the HIFU interference was significantly minimized.