A hand device called the Tacit can help the blind and visually impaired move around safely in complex environments. Wrist-mounted, the device uses ultrasonic sensors mounted above the knuckles that can pick up the distance of objects from one inch to 10 feet away and then translate that distance to pressure on the wrist–the closer the object, the more pressure on the wrist. Pressure is applied on the right or left side of the wrist to help the user determine where the obstacle is located.
The device can be strapped on to either hand and one-size-fits-most. The device shows a fast response time, in fractions of a second. A blind or visually impaired person can sense what is in the immediate area with a sweep of the hand. The inventor, Steve Hoefer, chose the word Tacit to describe the haptic-feedback invention, he wrote, because “it just seemed like an appropriate name that’s a lot shorter (though less descriptive) than ‘Hand-Mounted Haptic Feedback Sonar Obstacle Avoidance Assistance Device’.”
As interesting as the device is, what has attracted much buzz is the fact that the device, more formally called The Tacit Project, is under a Creative Commons License, and the project has been dedicated as a DIY idea for others to build. Hoefer’s site, Grathio Labs, has posted source code, a list of parts, and detailed diagrams, with an invitation to make the device. “I am active in the Open Source software and hardware and encourage community innovation and creativity,” he says on his site. He is using the Creative Commons BY-NC-SA license, which he explains as a “Don’t be a jerk” license. “In short: Make it, learn from it, teach it, improve it, modify it. Just share what you do, give credit, and don’t sell any without contacting me first.”