The Tacit, a haptic sonar glove that helps a visually impaired person navigate complex environments, has been released as a public prototype. The invention uses ultrasonic sensors to sense objects from about 1 inch to 10 feet away, and translates that information into pressure on the user's wrist.
While similar devices have taken the form of a headband or cane, the inventor says that he chose to develop a wrist-mounted device because most dangerous obstacles are waist level or lower, and because vibrating motors are also more comfortably applied to one's wrist than one's head. The cost of materials for the project is also just $65 USD, according to the inventor.
Read more details here.