ERI: Representation of Braille Characters and Graphical Patterns using Dynamic Tactile Displays

Chapman University, Orange CA

Investigators

Abstract

Braille displays are commercially available assistive devices that help the blind/visually impaired (VI) access digital information. However, braille displays are very expensive and are generally designed to display text only. The main reason for the high cost of the braille displays is the large number of braille cells used to provide tactile feedback. This research aims to identify how braille text and graphics can be effectively presented on the same platform integrated with a smartphone, using a small grid of tactile pins, at a much-reduced cost. A mobile tactile display will be developed that converts the images touched on the mobile screen to tactile images presented onto the fingertips of the user. This will help the blind/VI user feel the trends in charts and map directions providing access to vital information which currently needs to be printed out on embossed papers. Representing both braille and graphics on a display attached to a mobile device will help people with visual impairment explore a touchscreen as effectively as their sighted counterparts even in noisy environments where audio feedback is less reliable. This project will also address the braille literacy crisis by engaging the younger VI generation with tactile information presented through charts and trends and helping them realize the significance of braille over audio representations alone. The understanding gained from this research will enable the future development of wearable tactile displays and tactile texture representation on smartphones. The mobile tactile display will be tested on both VI and sighted users to study their adaptability towards the system. This project will also provide undergraduate and graduate engineering students an opportunity to participate in the complete development cycle of an assistive device, working in close collaboration with the VI individuals. The overall goal of this project is to integrate braille and graphics on the same platform, using a small dynamic tactile grid. This project will characterize user acceptability of a dynamic tactile system when the braille or graphical patterns are presented in a personalized manner (calibrated for user preferred vibration, slip-speed, etc.). An initial 6x6 refreshable tactile grid has been developed, with pin spacing adhering to braille standards and resolution capable of presenting straight lines and curves (or simple graphics). This initial prototype will be utilized to perform systematic studies on how VI read braille and graphics presented to stationary or semi-stationary fingers. The tactile patterns will be presented using different methods - sequential movements, column-wise, as well as simultaneously on the tactile display. The braille and graphics patterns will also be presented using stationary and vibrating pins, with and without sliding motion. A comparative study, between the finger movement while exploring freely on paper versus on the tactile display, will be performed to understand system limitations and possible enhancements. The effectiveness of each presentation method will be evaluated based on user response, response speed, comprehension, and likeability. The secondary goal of this project is the knowledge generation on how sighted users interact with passive tactile displays and their adaptability towards such systems. A mobile tactile display will be developed with software that converts touchscreen images into low-resolution simple graphics that continuously transfer graphics to tactile display. The efficacy of this system will be evaluated on 20 VI subjects, plus a few sighted users, to assess their ease of use, and ability to read and comprehend both braille text and mobile graphics. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.