Synthetic aperture (SA) is a technique that enhances the image resolution by synthesizing information from multiple subapertures. The application of this technique for medical ultrasound imaging has been an active research area, but the resolution improvement is limited by the physical size of the ultrasound array transducer. With a large F number (depth to aperture-size ratio), it is hard to achieve high resolution at deep regions without extending the effective aperture size. In this project, we investigate experimentally an approach to extend the available aperture size for SA by sweeping the ultrasound transducer using a precise robotic arm.
 Zhang, Haichong K., Ezgi Ergun, Gregg E. Trahey, and Emad M. Boctor. “Synthetic aperture ultrasound imaging with robotic aperture extension.” In SPIE Medical Imaging, pp. 94190L-94190L. International Society for Optics and Photonics, 2015.
 Zhang, Haichong K., Ezgi Ergun, Gregg E. Trahey, and Emad M. Boctor. ” In Vivo Visualization of Robotically Implemented Synthetic-Tracked Aperture UltraSound (STrAtUS) Imaging System Using Curvilinear Array.” In SPIE Medical Imaging. International Society for Optics and Photonics, 2016.