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University of Hawaii

Electrical Engineering

Signal Processing and Decision Making Algorithms in Vision Screening

Date: 2018-07-19           Add to Google Calendar
Time: 11:00am-12:00pm
Location: Holmes Hall 389
Speaker: Dr. Boris Gramatikov Ophthalmic Instrumentation Development Lab Wilmer Eye Institute, Johns Hopkins University School of Medicine


This talk is about utilizing the birefringent properties of the human fovea in the design of ophthalmologic diagnostic instrumentation. Our laboratory is developing novel technologies for Retinal Birefringence Scanning (RBS) - a technique that uses the changes in the polarization state of light returning from the fundus, to detect the projection into space of the radial array of birefringent Henle fibes surrounding the fovea. This allows eye tracking and detection of accurate pupillary light reflex methods. In a binocular setting, RBS allows precise checking for eye alignment, which is important in testing/screening for amblyopia ("lazy eye"), a major health problem.

The presentation focuses on two major application: a) a family of pediatric vision screeners, and b) a combined system where RBS technology is guiding the data acquisition and/or analysis in an Optical Coherence Tomography (OCT) system (in collaboration with Duke University). Both projects include design optimization using computer model of polarization-sensitive systems, incorporating Mueller matrix modeling and Poincare sphere representation. Special attention will be paid to signal processing methods developed to enable the detection of short lasting moments of central fixation, as well as classification and decision making methods that provide reliable automated screening. The talk may be of interest to colleagues working with polarized light, optical sensors, photonics, medical devices and classification methods, including learning algorithms.


Boris Gramatikov obtained his Dipl.-Ing degree in Biomedical Engineering from the Technical University of Illmenau, Germany, and his Ph.D. from the Technical University of Sofia, Bulgaria. After completing a number of postdoctoral studies in Germany, Italy and the United States, he joined the faculty of the Biomedical Engineering Department of The Johns Hopkins University (JHU) in 1996. In 2000 he moved to the Laboratory of Ophthalmic Instrumentation Development at the Wilmer Wye Institute (JHU). He is a member of the IEEE, having chaired the Baltimore BME chapter (1998-2000), the Baltimore Section in 2006, and being the Section's Director for Continuing Education since then. He is also a member of the Continuing Education Committee of the Educational Activities Board of the IEEE. Dr. Gramatikov's areas of expertise are electronics, optoelectronics, biophotonics, opthalmic optics, computers, computer modeling, signal/image processing, and instrumentation design, all applied to the development of the diagnostic methods and devices for ophthalmology and vision research. His team has developed a series of pediatric vision screeners. Together with Dr. Cynthia Toth from Duke University, Dr. Gramatikov is the co-PI on a project for combining Optical Coherence Tomography (OCT) with retinal birefringence scanning, to enable and optimize OCT imaging in toddlers and young children. He serves as a reviewer and editorial board member with a number of technical and medical journals.