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.
Bibliographical noteFunding Information:
The research was funded by a National Institutes of Health Grant (NIH) awarded jointly to Advanced medical Electronics (AME) with Kevin Kramer as PI, the University of Minnesota (Gordon Legge, PI) and the University of Southern California (USC, with Bosco Tjan as PI). For administrative purposes, the primary recipient of the grant was AME, with the University of Minnesota and USC funded through subcontracts to AME. Three of the authors—Gary Havey, Kevin Kramer and David Rolkosky—performed contributions to the project as employees of AME. This funding mechanism does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.