SciTech

How Things Work: BrainPort

Technology has allowed blind people to finally have rudimentary sight, but not through their eyes. BrainPort, being developed by Wicab, Inc., is a device in which electric signals sent through a blind person’s tongue translate into vision in the person’s brain. Although still awaiting FDA approval, BrainPort could be the next generation technology that will allow the blind to finally participate in activities that require sight.

BrainPort is composed of three main parts: a camera that captures light and translates it into data, a CPU that translates the radio signals from the camera, and the BrainPort electrode array, which feeds the electric stimulation to the brain through the tongue.

Electrotactile stimulation for sensory augmentation is the process by which coded electrical impulses are read by the brain as sensory information. In human eyes, light data is read by the retina and sent to the brain in the form of nerve impulses. Here, the camera of the BrainPort acts as the retina, and the tongue receives the input and sends it to the brain via nerve impulses.

The camera connected to the port takes the light data and translates it into digital signals. Pixel information from the camera is then fed to a portable CPU, which takes the data received and creates a spatially encoded signal. As stated on the website of the U.S. Patent Office, “[The encoded signals] may convey multidimensional information in much the same way that the eye perceives color from the independent stimulation of different color receptors.” Differences in the voltage, frequency, or duration help create a unique picture, which the brain interprets into vision. The CPU is connected to an electrode array, which transmits the signals to the tongue, and eventually the brain.

The BrainPort contains a small square-shaped electrode array that is placed on the person’s tongue, and feeds signals to the nerves on the tongue by means of painless currents. These currents are light images from the camera converted into electric pulses. The tongue, which receives the signals, acts as a nerve gateway to the parietal lobe of the brain. Normally, the parietal lobe is used for interpreting touch information, but scientists are trying to figure out whether the brain can adapt to different nerve pathways. The tongue is ideal for acting as a sensory receptor as its nerves are numerous and are close to the surface, which allows better transmission of the signals from the BrainPort. Another factor that makes the tongue a good receptor is the fact that saliva from the mouth contains electrolytes, which help conduct the flow from the array to the nerves. The brain takes the signals received from the electrode array and creates “sight.”

Studies have shown that with the use of a BrainPort, the blind can see a low-resolution version of the image in front of them. The tongue is capable of receiving more information to produce a higher resolution picture, but according to Wicab, Inc., research and technology is too expensive at the moment. As shown in videos on the website of Wicab, Inc., test subjects are able to sense and identify letters of the alphabet, a variety of objects placed in front of them and, for blind mountain climber Erik Weihenmayer, successfully rock climb. On its website, Wicab, Inc. claims that, “With the current system (arrays containing 100 to 600+ electrodes), study participants have been able to recognize high-contrast objects, their location, movement, and some aspects of perspective and depth.”

Other uses of the BrainPort fall under the category of military-related functions. The Defense Advanced Research Projects Agency has granted Wicab, Inc. money to further develop this technology so that Navy Seals can have better feel and vision in underwater or explosive-related missions. If this technology does become available for public use, the estimated price will be around $5000. Many criticisms include the bulky and awkward positioning of the electrode array and CPU and the low-quality resolution images. The question now arises whether it is worth spending so much time and money on a device that does not give perfect vision and also gives an awkward appearance. However, for those who have seen nothing but darkness since their birth, the prospect of vision, even if it is not of a high quality, may be endearing.