PhD Defense: "Image Reconstruction for Multistatic Stepped Frequency-Modulated Continuous Wave (FMCW) Ultrasound Imaging Systems with Reconfigurable Arrays"

Michael Lee

October 3rd (Friday), 2:00pm
Harold Frank Hall (HFH), Room 4164

The standard architecture of a medical ultrasound transducer is a linear phased array of piezoelectric elements in a compact, hand-held form. Acoustic energy not directly reflected back towards the transducer elements during a transmit-receive cycle amounts to lost information for image reconstruction. To mitigate this loss, a large, flexible transducer array which conforms to contours of the subject’s body would result in a greater effective aperture and an increase in received image data. However, in this reconfigurable array design, element distributions are irregular and an organized arrangement can no longer be assumed. Phased array architecture also has limited scalability potential for large 2D arrays.

This research work investigates a multistatic, stepped-FMCW modality as an alternative to array phasing in order to accommodate the flexible and reconfigurable nature of an array. A space-time reconstruction algorithm was developed for the imaging system. We include ultrasound imaging experiments and describe a simulation method for quickly predicting imaging performance for any given target and array configuration. Lastly, we demonstrate two reconstruction techniques for improving image resolution. The first takes advantage of the statistical significance of pixel contributions prior to the final summation, and the second corrects data errors originating from the stepped-FMCW quadrature receiver.

About Michael Lee:

Michael Lee graduated in 2006 with a B.S. in Electrical Engineering from the University of California, Santa Barbara. He received an M.S. in Biomedical Engineering in 2008 from the University of California, Los Angeles, and in 2011, joined Professor Liebling's group.

Hosted by: Professor Michael Liebling