----- Original Message ----- "Seeing" with your tongue - sensory substitution using a simple alternative to
the retinal chip. Abstract. Purpose: Sensory substitution refers to use of an alternate afferent sensory channel to communicate with the central nervous system when the originalend-organ is sufficiently damaged to preclude its use or repair. The BrainPort
(Wicab, Inc.) uses a spectacle frame mounted video camera coupled to an intra-oral tongue display as a paired substitute for the eye. Theelectro-tactile stimulation produced by an electrode array placed on the tongue
allows users to interpret objects in their ambient surroundings. We assessed whether the use of the device influenced a subjects’ ability to navigate a standardized obstacle course. Methods: Twenty human subjects (n= 16 blind and n=4 control, sighted and blindfolded) ages 22 to 75 years were provided approximately 20 hours oftraining each on the BrainPort. The camera on the current prototype has a field
of view of 73 degrees and uses a tongue stimulation array one-inch squarecontaining 400 electrodes. Blind subjects had light perception or worse vision. We used a modified Tangent Screen with 5cm objects, 2x2m screen at 1 m, and a
validated 40-foot obstacle course to administer baseline and post-trainingtests. The primary outcome measure for the obstacle course was the percentage of
the preferred walking speed (PPWS) achieved (ratio of time to walk 40 feet unobstructed divided by the time to navigate the course with the BrainPort). Results: We found that our subjects manifested an average of 58.6 degrees of“visual field,” with 60.1 degrees in the horizontal meridian and 57 degrees in
the vertical meridian with the device. There was no significant differencebetween blind and control subjects or with increased use over 6 weeks. Compared
to baseline, all subjects paradoxically slowed down after training with theBrainPort (PPWS 3.92 vs 1.90% P=0.001) because, per video review, they were now
searching for objects in their paths. With additional experience through the course, the subjects’ speed increased, approaching their time through the unobstructed course (PPWS 1.94 vs 1.90%) Conclusions: Electrical stimulation of the tongue via signals sent from a spectacle-mounted video camera results in a sensation akin to vision, and enables a perception of one’s surroundings that can be useful. The extent ofvisual field is sufficiently large to enable navigation with obstacle avoidance. As transducers become sophisticated with denser electrode arrays, the utility of
this device will likely be enhanced. Furthermore, such a device may be beneficial in screening subjects for retinal chip implants. By Thomas R. Friberg, Amy C. Nau, Christine Pintar, Christopher N. Fisher and Wendy S. Chen. Sunday, May 01, 2011, 8:30 AM -10:15 AM, 109/A244. Source URL: http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=3a3236e5-e3ce-4762-bd98-08c95b2964cd&cKey=b9ffe3da-b69d-41d8-b0da-4d4f7149af94&mKey={6F224A2D-AF6A-4533-8BBB-6A8D7B26EDB3} ---------- To send a message to the list, send any message to blindza@xxxxxxxxxxxxx ---------- To unsubscribe from this list, send a message to blindza-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject line --- The 'homepage' for this list is at http://www.blindza.co.za