Computer Vision and Image Processing of Video for Objective Analysis of Cataract Surgeon SkillsExport this event to calendar

Friday, April 10, 2015 — 3:30 PM to 4:30 PM EDT

We are honoured to welcome Alexander A. Sawchuk, Ph.D., to speak in the School of Optometry and Vision Science. Dr. Sawchuk is part of the Signal and Image Processing Institute, Ming Hsieh Department of Electrical Engineering, University of Southern California.

Abstract

The evaluation of the cataract surgical technique of residents in training has previously been done by panels of human experts viewing video clips of their procedures. This method is tedious, unreliable, time-consuming, and is subject to inter-observer variability. Thus, the motivation for this work is to develop scientific and objective methods for measuring surgical skills as an assessment and teaching aid to facilitate resident learning and patient safety. We focus on the capsulorhexis part of cataract surgery and describe computer vision and image processing methods to analyze video clips of the procedure. We use a circular Hough transform to identify the limbus and pupil, and define a search template that is matched with all video frames in the sequence by correlation techniques. The result is a stabilized image in which the limbus and pupil is registered in each frame. The limbus and pupil are outlined in each frame using a constrained shape tracking ("snake") algorithm. We then identify surgical instruments entering and leaving the eye using segmentation, edge detection, skeletonizing, Hough transforms, and model-based procedures. The goal is to make measurements of instrument movement as features relevant to the skill of the surgeon, and correlate them with the evaluations done by the human observers. The appearance of the eye in the video clips varies dramatically due to differences in illumination in each operation and the variability of each patient. Thus a particular challenge is to make the procedure operate reliably for all video clips.
 
This is collaborative work with Ronald J. Smith, M.D., MPH, UCLA; Xue Wang Ph.D., Nimit Desai, M.S., Saurabh Mistry, M.S., USC.

Biography

Alexander A. Sawchuk received the S.B. degree in electrical engineering from the Massachusetts Institute of Technology, Cambridge, MA, and the M.S. and Ph.D. degrees in electrical engineering from Stanford University, Stanford, CA. He is Leonard Silverman Chair Professor in the Ming Hsieh Department of Electrical Engineering at the University of Southern California. He has served in the past as Director of the Signal and Image Processing Institute, and as Deputy Director of the Integrated Media Systems Center (IMSC). His research interests are in optical information processing, image processing, immersive media technology, wireless health, body area networks, multimodal sensing and pattern recognition. He is a Fellow of the Optical Society of America (OSA) and the International Society for Optical Engineering (SPIE). He received the USC Associates Award for Excellence in Teaching, the OSA Distinguished Service Award and other awards. He has served in various capacities for IEEE, OSA, SPIE and the International Commission for Optics (ICO). He was Associate Editor for the OSA journal Optics Letters, and was Editor of the Information Processing Division of Applied Optics. He is currently chairman of the Board of Directors of the OSA Foundation.

Location 
OPT - Optometry Building
Room 350
200 Columbia Street West

Waterloo, ON N2L 0A7
Canada

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