Introduction to Brain-Computer Interface (BCI)
Brain-Computer Interfaces, BCI, is a system that can read and interpret brain signals, and the information can then be used to control devices or perform tasks. BCI technology is based on the principle that our brains generate electrical signals when we think or perform specific actions. These signals can be measured and interpreted using specialised equipment. For example, BCI could be used to control prosthetic devices or to help people with communication disorders.
Every BCI system consists of five components: brain activity measurement, pre-processing, feature extraction, classification, and translation into a command.
The above figure depicts a typical block diagram illustrating the various stages of EEG signal processing for BCI.
- In the signal (brain activity) acquisition phase, the brain activity from the targeted user is captured through the various types of EEG sensors.
- The artifacts included in the raw data are eliminated in the pre-processing phase.
- Feature extraction aims at describing the signals by a few relevant values called “features;” often, at this stage, the selection of significant features is also investigated.
- In the classification phase, the features are classified using different machine learning and deep learning algorithms.
- Finally, the classified outcomes are converted into device commands to develop real-life BCI applications.
A Brief History of BCI Development
In Ancient Egypt, electric catfish were used to shock people to treat the arthritic pain. It was also the first natural arthritis pain relief method. The next record was First-century AD, when Romans used black torpedo fish to treat headaches.
In the 1780s, Luigi Galvani of Bologna showed that muscle and nerve cells have an electrical force that makes muscles contract and sends messages to the brain. In 1875, Dr Richard Caton of Liverpool used a galvanometer to observe electrical impulses from living rabbits' and monkey brains' surfaces.
The first animal electroencephalography (EEG) was published in 1912 by Ukrainian physiologist Vladimir Pravdich-Neminsky. Almost twelve years later, in 1924, German physiologist and psychiatrist Hans Berger recorded the first human EEG.
In 1935, Frederic Gibbs, Hallowell Davis, and William Lennox of Harvard Medical School reported on using EEG to demonstrate epilepsy, and by 1952 Spanish neuroscientist José M Delgado began implanting radio-equipped electrode arrays in animals and humans.
A couple of years and innovations later, one of the earliest examples of a working brain-machine interface came when American composer Alvin Lucier used EEG to compose music in 1965. In the same year, Gordon Moore published a seminal paper on doubling the number of components per integrated circuit.
In 1968, Robinson introduced the first metal microelectrode and in the next year, American otologist William House installed the first cochlear implant that was not rejected by the patient’s system. In the same year, Eberhard Fetz at the University of Washington in Seattle showed that a monkey could learn to control the needle of a meter using only its mind for the first time.
However, the term ‘brain-computer interface’ was coined in 1973 by Professor Jacques Vidal of the University of California at Los Angeles, who also laid out the aims of the BCI project to analyse EEG signals.
Since then, numerous researchers have played a significant role in the advancement of BCI tech.
Types of BCIs
The image above gives a more detailed explanation of types of BCIs based on dependability, recording, and mode of operation.
There are three main types of brain-computer interface (BCI): invasive, non-invasive, and semi-invasive.
- Invasive BCIs require surgery to implant electrodes directly into the brain. This is the most invasive type of BCI but also the most accurate. Invasive BCIs are typically used for people with paralysis or other conditions that make communicating challenging.
- Non-invasive BCIs use electroencephalography (EEG) to measure brain activity. EEG is a safe and painless way to measure brain activity, but it is not as accurate as invasive BCIs. Non-invasive BCIs are typically used for research purposes.
- Semi-invasive BCIs use electrodes implanted into the brain, but not as deeply as invasive BCIs. It’s less invasive than invasive BCIs but more accurate than non-invasive BCIs. Semi-invasive BCIs are typically used for people with conditions that make communication difficult.
How Can Brain-computer Interfaces Change Our Lives?
A brain-computer interface, or BCI, is a system that translates brain signals into commands that a computer can carry out. This might sound like science fiction, but BCIs are being used today to help people with paralysis or other conditions that make it challenging to communicate with the outside world. This technology has the potential to revolutionize the way we interact with the world, and it is already changing the lives of people with disabilities.
BCIs are still in the early stages of development, but as they become more sophisticated, they have the potential to change our lives in a number of ways. Here are just a few of the ways BCIs could impact our lives in the future:
- Increased Communication
BCIs could help people unable to speak due to conditions like ALS, LIS, or cerebral palsy. BCIs could help these individuals communicate with the outside world by translating brain signals into speech.
2. Improved Mobility
BCIs could also be used to improve mobility for people with paralysis. By translating brain signals into commands, BCIs could help people with paralysis operate exoskeletons or other assistive devices. This could eventually lead to greater independence for people with paralysis.
3. Enhanced Cognition
BCIs could also be used to enhance cognition. For example, people with memory impairments could use BCIs to remember forgotten information. Or, healthy individuals could use BCIs to boost their memory or other cognitive functions.
4. Increased Efficiency
BCIs could also be used to increase efficiency in a variety of settings. For example, surgeons could use BCIs to access information hands-free while operating. Or, office workers could use BCIs to type faster or access information without taking their hands off the keyboard.
5. New Therapies
BCIs could also beused to develop new therapies for depression or anxiety. For example, BCIs could help people with anxiety learn to control their thoughts and emotions. Or, BCIs could be used to help people with depression get in touch with their positive thoughts and emotions.
