Device Worn on Tongue Allows the Blind to See
More info from the research page...
What we have developed is a generic and flexible way to communicate information to people using an array or matrix of small electric stimulators on the surface of the tongue. In much the same way that people can use their fingertips to read Braille letters, which are patterns of raised dots embossed onto a sheet of paper, people can recognize simple spatial patterns using comfortable electrical stimulation of the tongue. For example, we published a preliminary study about two years ago showing that volunteer experimental test subjects could identify very simple geometric patterns such as circles, squares, and triangles. They identified these figures as accurately on the tongue as on the fingertips. And that's when we became excited about the possibilities for a tongue-based electrotactile display, electrotactile being the technical term for electrical stimulation of the sense of touch.
The electrical stimulus on the tongue feels like a tingle or vibration; some users have said it feels like soda bubbles. The sensation is well-controlled and not painful unless the user deliberately turns up the level too high. Occasionally it will produce weak metallic taste sensations, a minor side effect. We have never observed any kind of tissue irritation with the gold-plated electrodes.
1. One of the applications which has been commercialized is providing vestibular or balance information for people with balance disorders. This is a simple form of sensory substitution, in which the tongue is used to present information from an artificial balance sensor.
2. Another application is providing directional or navigational information for people who operate under central command and control scenarios, such as military and civilian rescue personnel. Providing information via the tongue allows them to fully use their vision and hearing to respond to unforeseen threats or hazards. We have shown in the laboratory that it is possible to navigate a virtual maze (like a simple video game) using only information received on the tongue (i.e., buzz on right side of tongue means turn right, etc.).
3. A third, more ambitious application would be providing very crude visual information through the tongue for persons who are completely blind. Our colleague Eliana Sampaio at the Louis Pasteur University in Strasbourg, France has used our tongue stimulator with a small video camera and demonstrated an equivalent visual acuity of about 20-to-830, which is very poor vision, but possibly useful for certain limited activities with enough practice. Wicab, Inc continues to improve this technology with the aim of commercializing it.
4. A fourth application would be providing tactile feedback to the human operators of robots used forhttps://www.instructables.com/edit/new?type=forumTopic various tasks. For example, UW professor Nicola Ferrier is developing a robot controlled by the tongue of persons with quadriplegia which could incorporate touch sensors into its gripper, relaying the touch information back to the user's tongue.
This summary taken from Synopsis of Tongue Display Technology 1/3/2008. Lots more information on the research page.
More info on the general process of electrotactile stimulation here.
(I can't believe that I am actually linking to How Stuff Works for this, but hey, there isn't an Instructable written for everything...yet.)