Infrared goggles and an array of vibrating pads can give people who are blind an intuitive way to navigate while also retaining full use of their hands and ears, unlike many devices on the market.
and Armaghan Ahmad Khan at the Technical University of Munich in Germany installed a pair of infrared cameras into 3D-printed prototype goggles to capture a stereoscopic image that a small computer can use to create a map of what lies ahead. This map is converted into a low-resolution image on a five-by-five grid, which is then presented to the user via an array of 25 vibrating pads on an armband that reveals details about the nearby environment.
For instance, if the wearer walks down a narrow hallway, they sense stronger vibrations on the edges of the grid to show the presence of walls and weaker vibrations in the centre as objects are further away in that direction. If a user walks towards an obstacle, the vibration intensity of the respective pads on the armband gradually increases in the corresponding spot. Because the system uses infrared, it works even in total darkness.
Advertisement
Five volunteers who used the device were able to navigate an indoor test route even on their first attempt. The average time taken to complete the route decreased during weekly tests from 320 seconds in the first run to 148 seconds two weeks later on the third attempt, although the same course was used each time, leaving open the possibility of memorisation.
Zahn says existing navigational aids often involve expensive robots or else rely on approaches that fully occupy another of the wearer鈥檚 senses. Some, for instance, require the user to wear headphones and so reduce their ability to respond to audio clues from the environment when navigating.
Designing the armband was a challenge: it had to be large enough for the wearer to distinguish between the vibrating pads and to extract the information, says Zahn. 鈥淏ut besides that, it鈥檚 fairly intuitive,鈥� he says. 鈥淵ou quickly learn that when you move, the vibration moves on your arm as a lower-resolution representation of your surroundings.鈥�
Zahn believes that a refined version of the goggles can be produced and that the rest of the device will fit entirely into a stretchable armband that can be worn inconspicuously underneath clothes.
Reference:
