Feeling the Way

For many people, it has become routine to go online to check out a map before traveling to a new place. But for blind people, Google maps and other visual mapping applications are of little use. Now, a unique device developed at MIT could give the visually impaired the same kind of benefit that sighted people get from online maps. The BlindAid system, developed in MIT’s Touch Lab, allows blind people to ‘feel’ their way around a virtual model of a room or building, familiarizing themselves with it before going there. The director of the Touch Lab is working with the Carroll Center for the Blind in Newton, Mass., to develop and test the device. Preliminary results show that when blind people have the chance to preview a virtual model of a room, they have an easier time navigating their way around the actual room later on. That advantage could be invaluable for the visually impaired. One of the toughest challenges a visually impaired person faces is entering an unfamiliar environment with no human or dog to offer guidance.

The BlindAid system builds on a device called the Phantom, developed at MIT in the early 1990s and commercialized by SensAble Technologies. Phantom consists of a robotic arm that the user grasps as if holding a stylus. The stylus can create the sensation of touch by exerting a small, precisely controlled force on the fingers of the user. 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. The team has tested the device in about 10 visually impaired subjects at the Carroll Center, a non-profit agency that offers education, training and rehabilitation programs to about 2,000 visually impaired people per year. To successfully use such a system, the visually impaired person must have a well-developed sense of space.

More information:

http://web.mit.edu/newsoffice/2009/touch-map.html