We are in a modern world where most of the science fictions are made into a reality. Think of a paralyzed person who become independent by controlling a wheelchair or a neuroprosthesis and convey their needs and wishes to others. Yes, it’s not an imagination or a part of a movie now. Brain computer interface (BCI) is a technological breakthrough which improves the livelihood of people with severe disabilities.
Simply a brain computer interface system controls external devices through brain activities. It is also called as Neural Control Interface (NCI), Mind Machine Interface (MMI), Direct Neural Interface (DNI) or as a Brain Machine Interface(BMI). Although it is basically directed towards medical usage, its non-medial usage also plays a vital role. For an example, BCIs are widely used in virtual reality games.
The history of BCIs run towards the discovery of the electrical activity of the human brain in 1924. The earliest example of the BCI was the piece music for solo performer which was invented by an American composer in 1965. Later, the experiments of Professor Jacques Vidal contributed a lot to the development of BCIs. The two non-invasive Electroencephalographs (EEGs) controlling a graphical object on a computer screen and a robot and a BCI controlling a computer buzzer are some of the key experiments done on this subject area. On the other hand, several researches have been conducted using animals. Interesting photographs are available on internet which show a robotic arm is operated by a monkey through a BCI. The outcomes of several studies enabled the researchers to upgrade the BCIs to detect complex brain motor cortex signals by recording from neural ensembles and using these to control external devices.
There are three kinds of BCIs being used. They are invasive, partially invasive and non-invasive BCIs. Invasive BCI is the most accurate type where the electrodes are implanted surgically under scalp. The electrodes then measure minute differences in the voltage between neurons. Next, the signal is filtered and amplified. Finally, a computer network is responsible in interpreting it. On the other hand, many side effects such as scar tissue formation is reported under this type. Invasive BCIs commonly target repairing damaged sights, restoring movement of the paralyzed people or to provide external devices such as interfaces with computers or robotic arms. Partially invasive BCIs are implanted inside the skull but rest outside the brain. Here a scar tissue isn’t formed. Non-invasive type is not useful as it provides only a poor spatial resolution and also high frequency signals cannot be used. Helping people with disorders of consciousness, reeducation of motor function and BCIs controlled by thoughts are some of the future appliances of BCIs.
So, lets wish a date to shake a robotic hand of a paralyzed person and to reward BCI technology for becoming their redeemer.