Sunday, December 6, 2009

Help for the Visually Impaired

MIT’s Touch Lab has developed a device called the BlindAid system to enable the visually impaired to feel their way around a virtual model of a room or building. Mandayam Srinivasan, Director of the MIT Touch Lab and affiliated with the Research Laboratory of Electronics and the Department of Mechanical Engineering is working on this project with the Carroll Center for the Blind in Newton Massachusetts.

The BlindAid system builds on a device called the Phantom, developed at MIT in the early 1990’s and commercialized by SensAble Technologies. Phantom consists of a robotic arm that the user can grasp as if holding a stylus. The stylus then creates the sensation of touch by exerting a small, precisely controlled force on the fingers of the user.

Orly Lahav, a former postdoctoral associate in the Touch Lab, and David Schloerb, a research scientist in MIT’s Research Laboratory of Electronics, did most of the work to develop and build the device. Lahav presented their work at the Virtual Rehabilitation 2009 International Conference held in Israel last summer.

The BlindAid stylus functions much like a blind person’s cane, allowing the user to feel virtual floors, walls, doors, and other objects. The stylus is connected to a computer programmed with a three dimensional map of the room. Whenever a virtual obstacle is encountered, the computer directs the stylus to produce a force against the user’s hand, mimicking the reaction force from a real obstacle.

Srinivasan’s team has tested the device with ten visually impaired individuals at the Carroll Center. “To successfully use the system, the visually impaired person must have a well developed sense of space,” says Joseph Kolb, a mobility instructor at the Carroll Center. During the testing, Kolb realized that the device could also be used to help mobility instructors evaluate the exploration strategies the subject is using. The instructor is able to determine if the individual uses an organized approach or tends to get stuck in a certain area.

Once Srinivasan obtains additional funding, he hopes to incorporate the BlindAid system into the Carroll Center’s training program which will yield user feedback to help him refine the system for commercial production. In the long term, he believes the device could be used to help blind people not only preview public spaces but to also use the device to travel by public transportation by using virtual route maps and then be able to interact with the virtual map through touch.