A
brain-computer
interface or also known as a brain-machine interface is a system that allows a
person to control a computer or other electronic device using only his or her
brainwaves, with no movement required. Electroencephalogram (EEG) sensors of
human brain can be used to monitor the brain activity. Studies have shown that
even people who have lost muscle control can use BCI systems by changing their
brain activity so that a computer can detect their intent and translate it into
device control.
BCIs
can be used for communication, computer access, or control of devices such as a
wheelchair or prosthetic arm, among other applications. Virtually anything that
can be controlled by a computer could, potentially, be controlled by a BCI. BCI is mostly designed for people due to
brainstem injury or ALS. Amyotrophic
lateral sclerosis, commonly known as ALS or Lou Gehrig's disease, is a
progressive neurodegenerative illness that results in weakening of the
connections between the brain and body. In the late stages, these individuals
have no ability to move or speak, though for the most part they retain normal
cognitive function. This condition is referred to as "locked-in
syndrome" or LIS.
Many people with disabilities use
computers to communicate and to control their environments. However,
conventional methods for using computers, like typing on a keyboard or moving a
computer mouse, require muscle control and thus may not be useful for people
who have little or no muscle control. People who already have a reliable
method of controlling a computer or communication device (e.g. using hand,
foot, head, or eye movement) are likely to find that BCI is slower and more
complicated, and simply not worth the hassle. BCIs will be most beneficial for
people who have little or no reliable muscle movement.
Many
people imagine that BCI will allow them to simply think of a word or phrase and
have it appear on the screen, or control a wheelchair by thinking about where
they want to go. Unfortunately, this is not the case with current BCI
technology. There are a variety of types of BCI systems, and each one works a
little differently. People who use BCI system are required to spend
considerable time training to use the system and must be willing to accept a
fairly slow communication rate.
The picture above is the
standard 6x6 P300 speller matrix. Most
BCI spelling systems display a series of letters, either one at a time or by
highlighting letters in a grid. When the letter you want lights up, your brain
wave changes. The computer looks for that change and interprets it as a
'keystroke'. For example, at
the top the word "DOG" is presented then if you wanted
to type the letter D, you would focus on the D and count each time it flashed,
or think “Yes!” when you saw it appear on the screen. Recognizing the D would
trigger a spike in your brain signals, which would be detected by the BCI
system. Usually, each letter must be ‘selected’ multiple times, so typing with
a BCI is quite slow.
All
BCI systems require conscious effort from the user to type a message or move a
computer cursor. Systems designed to control a computer cursor often rely on
movement imagery. You would imagine squeezing your right hand to move the
cursor to the right, and your left hand to move the cursor to the left. The ultimate goal of research is to
develop a BCI system that is robust and portable enough to meet the
daily communication and social interaction needs of severely disabled
individuals.
Although most people are capable of using BCI technology, it is not for everyone. Current BCI systems are challenging to use, and require expensive equipment and time-consuming setup. Current brain-computer (BCI) systems utilizing P300 detection are still only available as research tools and development stage, and are not available for purchase or independent home use.
BCI
technology is constantly changing. The future will bring faster, more reliable
BCI systems that work for more potential users. Hardware will improve with
wireless electrode connections, and with dry electrodes that eliminate the need
for conductive gel to be applied to the user’s head. Software will provide new
options for typing and speaking messages; using the internet, email, and social
media; creating artwork; safely driving a wheelchair; controlling door locks,
light switches, entertainment systems, and other features of the home; and much
more. It is hoped that the cost of BCI will decline as it becomes more widely
used, and that insurance carriers will eventually cover it as an assistive
technology. Since this technology is being developed for a much larger market
than those with neurological disease, in the future we will see BCI devices
available for many computer functions.
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