Abstract
Purpose::
To develop a Low-Vision Goggle (LVG) based on an Image Transceiver Device (ITD) which combines both functions of imaging and display in a single CMOS chip [1]. The device allows a compact design of the LVG in which the imager captures the input imagery. Following the processing by a wearable computer, the processed imagery is displayed to the healthy part of the subject's retina. The design of the ITD device is based on an LCOS micro-display and an APS imager technology, in which the front side LCD and the back-illuminated imager are integrated onto a single silicon substrate.
Methods::
The device design effort includes both the chip and an FPGA system controller. In addition to the ITD development, the present effort also includes low vision modeling, image processing algorithms adapted for this system and optical design study of the low vision goggle.
Results::
A recent implementation of a deep-P-Well technology allows a reduction of 20-fold in the pixel cross talk, thereby enabling the use of 10 micron pixels required for the high resolution operation of the imager. In the area of Optical Design studies we have designed a See-through configurations which allows combining the optical paths of the imaging display and eye-tracking, Thereby enabling a compact design of the goggle with a foot-print size of regular eye glasses.In the area of Low Vision modeling we have combined Low vision CSF characterization based on eccentricity and illumination effects with a JND model, allowing a quantitative estimate of image discriminability for any arbitrary Low Vision CSF characterization. Finally in the area of Image Enhancement methods for the Visually impaired, we have developed a method allowing only salient image details to be enhanced, while suppressing the surrounding, low value edge and texture elements .
Conclusions::
Recent studies in the design of the ITD chip, The Optical design of the LVG, The Low Vision Modeling and the development of image enhancement methods , support the feasibility of a compact, eye-glasses- size Low Vision Goggle, based on the Image transceiver device, as an efficient mobile aid for the visually impaired.[1] Efron et al, "A head-mounted, image transceiver-based, low vision aid". Vision 2005 - Proc.Int'l Conf., April 4-7 2005, London, UK. Elsevier Int'l Congress Series, vol. 1282, 2005 .
Keywords: low vision • visual acuity • age-related macular degeneration