Synthetic aperture ultrasound imaging with robotic aperture extension

Haichong K. Zhang, Ezgi Ergun, Gregg E. Trahey, Emad M. Boctor

Research output: Chapter in Book/Report/Conference proceedingConference contribution


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 paper, we investigate experimentally an approach to extend the available aperture size for SA by sweeping the ultrasound transducer using a precise robotic arm. Pose information from the robots kinematic for the calibrated probe is used to synthesize the signals received at different positions; therefore the available aperture is wider than the size of transducer. To experimentally validate this approach, a robot arm (UR5, Universal Robot) was used to hold a 64 elements phased array transducer (0.32 mm pitch, 2MHz central frequency), and in-plane lateral translational motion was applied. A line phantom as a point source and an ultrasound phantom with wire targets and anechoic region were used for evaluation. The full width at half maximum of a reconstructed point source improved a factor of 2.76 by moving five poses with 10.24 mm step size. For the ultrasound phantom, the contrast-to-noise ratio of anechoic region enhanced 12% by moving three poses with the same step. Results indicate that the technique to robotically extend aperture has potential to improve theimage quality for SA ultrasound imaging.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2015
Subtitle of host publicationUltrasonic Imaging and Tomography
EditorsNeb Duric, Johan G. Bosch
ISBN (Electronic)9781628415094
StatePublished - Jan 1 2015
EventMedical Imaging 2015: Ultrasonic Imaging and Tomography - Orlando, United States
Duration: Feb 22 2015Feb 23 2015

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherMedical Imaging 2015: Ultrasonic Imaging and Tomography
Country/TerritoryUnited States


  • robotic tracking
  • synthetic aperture
  • ultrasound calibration
  • ultrasound imaging

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging


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