ABSTRACT
There is a need for adaptive technology to enhance indoor wayfinding by visually-impaired people. To address this need, we have developed and tested a Digital Sign System. The hardware and software consist of digitally-encoded signs widely distributed throughout a building, a handheld sign-reader based on an infrared camera, image-processing software, and a talking digital map running on a mobile device. Four groups of subjects-blind, low vision, blindfolded sighted, and normally sighted controls-were evaluated on three navigation tasks. The results demonstrate that the technology can be used reliably in retrieving information from the signs during active mobility, in finding nearby points of interest, and following routes in a building from a starting location to a destination. The visually impaired subjects accurately and independently completed the navigation tasks, but took substantially longer than normally sighted controls. This fully functional prototype system demonstrates the feasibility of technology enabling independent indoor navigation by people with visual impairment.
Subject(s)
Blindness/rehabilitation , Electronics, Medical/methods , Self-Help Devices/statistics & numerical data , Sensory Aids/statistics & numerical data , Visually Impaired Persons/rehabilitation , Adult , Aged , Blindness/physiopathology , Electronics, Medical/instrumentation , Equipment Design , Female , Humans , Male , Middle Aged , Movement/physiology , Reproducibility of Results , Software , Surveys and Questionnaires , User-Computer Interface , Young AdultABSTRACT
This paper details the research and development of the PC Vision system, a unique calibration and monitoring subsystem that will enable use of personal computers as accurately calibrated and controlled vision test instruments. The need for such a system is evident. Display intensity and chromaticity, test distance, room illumination, and a number of other variables must be controlled to avoid unexplained discrepancies in test outcomes, within and between individuals and test locations. Modern displays (CRT-, LCD-, or projector-based) have sufficient resolution, gamut, and stability to allow high-quality stimulus presentation. The PC Vision system consists of two categorical functions - one to calibrate screen properties, the other to monitor room and test setup conditions - packaged into a fully integrated hardware prototype.
