As GRAB project co-ordinator, Teresa Gutierrez from the Fundacion Labein explained: "Advances in information technology have, in recent years, helped to break down some of the barriers preventing persons with visual disabilities from accessing computers and their applications. For instance, by using screen reader software, speech synthesizers, Braille displays, or various forms of mouse, visually impaired persons can consult their mail, surf the Internet and so on. However, we saw that one area of technology still remained inaccessible, namely three-dimensional graphics."
The tool developed by the GRAB team is a haptic, or touch-sensitive, and audio virtual environment (HAVE), consisting of a two-finger haptic interface, a high force feedback workspace and a number of specially adapted applications. In order to experience a 3D object, a user inserts the thumb from one hand and the index finger from the other into contact holes situated on two co-ordinated arms, each with six degrees of freedom, covering a large portion of the desktop. Using the arms, the user moves his/her hands freely about to explore and touch the objects in the workspace. If the user has failed to explore the entire space, the interface will take control and guide the user towards any remaining objects.
The haptic interface detects the movement of the user's fingers and sends the new positions to the haptic geometric modeller. This analyses the new positions in order to calculate the value of the forces to be sent to the user through the haptic interface and to send the corresponding audio message. Finally, the haptic interface replicates the calculated forces on the user's fingertips.
Several applications have also been developed for the interface, including an application on virtual maps, an adventure game, and a chart data explorer. Depending on the application, users can receive audio feedback to provide information about the virtual objects, and information about the user's actual position within the environment. Users can also carry out verbal and keyboard commands and can zoom in and out to explore objects whose size is too big or small.
The first prototype of the GRAB system was tested in 2002. Since then, the team has been working to validate each of the applications that have been designed in parallel. "The feedback from the test has enabled us to identify the features and benefits that our tool can bring to blind people", stated Ms. Gutierrez. "We hope the tool will help blind and visually impaired people to integrate more freely in the labour market, where nowadays computers are essential tools, and improve their education and training opportunities in order to live independently."
However, plans to commercialise the product may take some time. "While it is our intention to bring this product to the market, we are aware that this type of tool is too expensive for individuals", explained Ms. Gutierrez. "For this reason we are looking into the possibility of selling the product to public authorities so that it can be placed at people's disposal in libraries and other public venues." For further information, you can visit the GRAB project Web site.