Our research group has developed a new, non-invasive technology using low intensity focused ultrasound to reposition kidney stones. This is essentially a conventional diagnostic ultrasound system that is also programmed with longer ultrasounds bursts (50 ms) to impart sufficient energy to physically move a stone. These are similar to pulses that may be used in elastography or acoustic radiation force imaging. Like conventional ultrasound, the probe is placed in contact with the patient's skin to image the stone following standard ultrasound imaging procedure. The same probe is then used to focus the ultrasound and apply a burst (a sequence of pulses) of acoustic force to push the stone. Brightness mode (B-mode) imaging is interleaved with the "pushing" pulses (Push-mode) to monitor stone movement. The Push can be applied to any location and any depth within the image. The user controls the burst amplitude. To control probe surface heating, and thus patient safety, the system is programmed to control when the user is allowed to conduct the next push.