Applications
Applications
Brain Machine Interface
Currently the field of brain-machine interfaces can be divided into two broad categories. There are devices which send signals to the brain, providing sensory substitution, and there are devices which extract signals from the brain to control external devices. In the latter group, progress has been made in enabling subjects with limited control analogous to native motor function. For instance, in 2003 researchers at Emory and Georgia Tech developed a primitive system which allowed a paralyzed individual to spell words by modulating brain activity. More recently, there have been successful experiments replacing limbs with robotic prosthetics controlled telekinetically (see video).
Sensory substitution devices have been more successful to date, if only because they have received more concentrated research efforts. Visual prosthetics interfaced directly with the brain have recently allowed individuals who were born blind to achieve low 
resolution vision. In this approach, a video camera is mounted to glasses worn by the patient, which feeds the signal into electrodes implanted in the patient’s visual cortex. The most successful brain-machine interface to date, however, is the cochlear implant. This device differs from conventional hearing aids in that it does not amplify sound, but rather records sound with a microphone, processes the signal, and stimulates the auditory nerve directly via implanted electrodes. At this stage, the cochlear implant doesn’t provide complete restoration of hearing ability, nor do the visual prostheses provide perfect vision for patients. However, these devices provide powerful improvements for their users, and also demonstrate the proof of principle in sensory substitution with brain machine interfaces.
Brain Machine Interface
by Matt Lincicum
