4B-3 Time Reversal Focusing of Short Pulses

Time reversal acoustics (TRA) provides a way to focus ultrasound in space and time. Standard TRA focusing system produces tone burst signal with a frequency band limited by the bandwidth of the transducer. For certain medical applications, both in therapy and imaging, a wider bandwidth is required. The goal of this study was to explore a possibility to generate shorter pulses less affected by the limited bandwidth of the transducers of the TRA focusing system. We proposed and tested a technique named "pseudo impulse response (pIR) method" which provides significant extension of the TRA focusing system bandwidth. In addition, the suggested method leads to a decrease of the spatial side lobes and also facilitates the task of creating multiple ultrasound foci.