( CNN ) -- It started out life as a new video game concept but quickly morphed into a prototype with a far more practical vision -- a haptic device to help the blind and visually impaired . Tacit is a wrist-mounted device which informs the wearer about the proximity of objects in complex environments , according to its creator Steve Hoefer . Ultrasonic sensors positioned at the front measure distances from one inch up to 10 feet ( 2cm to 3.5m ) , Hoefer says , while motorized rubber pads at the rear apply increasing amounts of pressure on the wrist as users get closer to an object . The original idea was rather different . Hoefer wanted to create a `` dungeon crawl '' game ( a type of fantasy role-playing adventure set in labyrinths ) that did n't rely on vision . So he built a haptic headband complete with sensors and vibration motors . It worked , but there was a problem . He kept crashing into things that were n't at head height and the vibrations drove him batty , he says . Moving the remodeled device to the back of his hand not only saved him a lot of stubbed toes , but also steered the project in its new direction . The prototype is powered by a standard nine volt battery and can be worn on either hand . It 's cheap too , with materials totaling around $ 75 , Hoefer says . So far , tests with the blind have been very positive , he says , and it 's attracting interest from educators , designers and researchers in the field . Robin Spinks , principle manager of digital accessibility at the UK 's Royal National Institute of Blind People thinks the device shows promise . `` Orientation and mobility are critical skills for a blind person 's independence , education , employment and quality of life . Electronic orientation devices , such as Tacit have the potential to enable individuals to move around independently and gain confidence , '' Spinks said . San Francisco-based Hoefer is currently working on reducing Tacit 's size as well as improving its accuracy and simplifying its construction . `` It 's not perfect , but it works , and it can be better , '' Hoefer said . `` It could easily be made about half the size , and the replaceable batteries should be replaced by rechargeables with a blind-friendly charging method -- either a wireless or magnetically-aligning power plug . '' `` One of the biggest and best criticisms is that it is very difficult for a blind person to build their own . I hope to address that in a future version , '' he said . Hoefer has released details of Tacit 's materials , circuits and software on his Grathio Labs web site under a Creative Commons license to maximise feedback and hopefully improve the design . `` There are a number of improvements and changes left to be made . I 'm curious to see what happens , '' he said .
San Francisco-based inventor devises cheap haptic device to help visually impaired . `` Tacit '' uses sensors which measure distances from one inch to 10 feet . The system is designed for people with visual impairments, but could be used by anyone who has trouble reading a map or navigating through unfamiliar areas.