Technology
Technology
Brain Machine Interface
The foundation for brain-machine interfaces is monitoring the neuronal activity of the subject. Recorded brain activity reflecting an individual’s motor 
intentions can then be used to control physical devices directly, such as computers, wheelchairs, or artificial limbs. Several different approaches have been developed for recording brain activity. A non-implantable method is to record electro-encephalographic (EEG) activity with removable electrodes on the surface of the scalp. Another method is to implant microelectrodes to detect the activity of single neurons. The brain regions of interest are the primary motor cortex, which is involved in controlling voluntary movements, and the premotor and posterior parietal cortex, which are involved in planning movements by providing instructions for the primary motor cortex.
The signals recorded are then matched to movements by the subject, or in the case of paralyzed patients, the
intention to move. The signals are then decoded and correlated to the movements of the patients. The brain signal can then be used to control an external device, such as a computer mouse. After some initial calibrations, and following some practice with the device, the patient is able to control the mouse quite easily. Currently, the patient is still required to be tethered to a bulky cart of electrical equipment, and implantable electrodes leave wires protruding from the skull, leaving the site vulnerable to infection. Shrinking electronics, more sophisticated decoding algorithms, and wireless communication devices aim to solve these problems in future stages of development.
Brain Machine Interface
by Matt Lincicum
