PREPARED BY:-

SAKSHI MONGIA

2808037

CSE final yr.

TOPICS TO BE COVERED…INTRODUCTION

HISTORY

BRAIN

TYPES OF BCIs

BCI WORKING

BCI APPLICATIONS

BCI PROJECTS

BCI DRAWBACKS

A Brain Computer Interface creates a direct link between the brain and a computer. It allows the computer to be controlled by the brain and in some cases can also send signals to the brain.

Brain-Computer Interfacing (BCI) can be used for capturing brain signals and translating them into commands that allow humans to control (just by thinking) devices such as computers, robots, rehabilitation technology and virtual reality environments.

In 1924 Berger was the first one who recorded an EEG from a human brain. By analyzing EEGs Berger was able to identify different waves or rhythms which are present in a brain, as the Alpha Wave (8 – 12 Hz), also known as Berger's Wave.

The Advanced Research Project Agency (ARPA) of the government of the United State of America became interested in this field of research. They had the vision of increasing the performance of mental high load tasks by enhancing human abilities with artificial computer power. But their attempt failed.

The first wireless brain-computer interface was buildby Philip Kennedy and his colleagues by implantingneurotrophic cone electrodes into monkey brains.

By the year 2000, Miguel Nicolelis' group implantedelectrode arrays into multiple brain areas of monkeys.They built a BCI system that was capable ofreproducing a monkey's movement, while reaching forfood or using a joystick in real time.

One of the first persons who benefit from all the years of BCI research is Matt Nagle. In 2004 an electrode array was implanted into his brain to restore functionalities he had lost due to paralysis.

The system required some training but finally he was able to control the TV, check emails and do basically everything that can be achieved by using a mouse. He could also open and close a prosthetic hand.

Our brain is the main reason why BCI work.

Our brains are filled with neurons, individual nerve cells connected to one another by dendrites and axons. Every time we think, move or feel, our neurons are at work.

Some kind of electric signals are generated by these nerves. These signals are generated by differences in electric potential carried by ions on the membrane of each neuron.

Scientists can detect those signals, interpret what they mean and use them to direct a device of some kind.

There are three ways in which BCI technology is implemented on humans. The three ways are:-

INVASIVE BCI

PARTIALLY INVASIVE BCI

NON INVASIVE BCI

Invasive BCIs are implanted directly into the grey matter of the brain during neurosurgery. As they rest in the grey matter, invasive devices produce the highest quality signals of BCI devices.

WILLIAM DOBELLE was the first scientist to use BCI in VISION SCIENCE.

In VISION SCIENCE, direct brain implants have been used to treat non-congenital (acquired) blindness.

In 1998 researchers at Emory University in Atlanta led by Philip Kennedy and Roy Bakay were first to install a brain implant in a human that produced signals of high enough quality to simulate movement.

In 2005, after nine months of human trial CyberkineticsNeurotechnology’s BrainGate chip-implant.

This brainGate chip is a technology used to cure patients suffering with paralysis and locked in kind of syndrome diseases.

Partially invasive BCIs is a milder or scaled down version of Invasive BCIs.

Partially invasive BCI devices are implanted inside the skull but rest outside the brain rather than amidst the grey matter.

Unlike Invasive BCIs these have low risk of formation of scar tissues in brain.

Non-Invasive BCIs rest outside the brain and tries tocapture the signals of the brain.

Although the waves can still be detected it is moredifficult to determine the area of the brain that createdthem or the actions of individual neurons.

They produce poor signal resolution because the skulldampens signals, dispersing and blurring theelectromagnetic waves created by the neurons.

Signals recorded in this way have been used to powermuscle implants and restore partial movement in anexperimental volunteer.

It uses following techniques:

Neuro-Imaging

Direct Neural Contact

Electroencephalography (EEG)

Magnetoencephalography (MEG)

Functional Magnetic Resonance Imaging (FMRI)

In these techniques a head cover with installed electrode is attached to the brain.

It is the main technique used in Non-Invasive BCI.

It measures the electrical activity of the brain.

Due to its ease of use, cost and high temporal resolution this method is the most widely used one in BCIs nowadays.

DRAWBACKS:-

In practice EEGs are highly susceptible to noise.

Another substantial barrier to using EEG as a brain–computer interface is the extensive training required before users can work the technology.

MEG is a much newer and more accurate technology.

Instead of measuring the electrical activity in the brain this technology records magnetic fields produced by it.

The main drawbacks of this technology are its high requirements in equipment.

This technique measures the haemodynamic response (blood flow and blood oxygenation) known as Magnetic Resonance Tomography (MRT).

In contrast to the MRI which studies the brain’s structure this method studies the brain’s function.

As this method requires MRI technology it needs very special equipment and thus is quite costly.

scientists can implant electrodes directly into the gray matter of the brain itself, or on the surface of the brain, beneath the skull.

The electrodes measure minute differences in the voltage between neurons. The signal is then amplified and filtered, it is then interpreted by a computer program.

In the case of a sensory input BCI, the function happens in reverse. A computer converts a signal, such as one from a video camera, into the voltages necessary to trigger neurons.

BCI APPLICATIONS Medical applications

BCIs provide a new and possibly only communication channel for people suffering from severe physical disabilities but having intact cognitive functions.

For example these devices could help in treating (or rather overcoming) paraplegia or amyotrophia, the most widespread neuroprosthetic is the cochlear implant or bionic ear. This device can help people with impaired hearing.

BCI APPLICATIONSHuman enhancement

Human enhancement describes any attempt (whether temporary or permanent) to overcome the current limitations of human cognitive and physical abilities, whether through natural or artificial means.

For eg. Brainwave synchronization is the practice to entrain one's brainwaves to a desired frequency, by means of a periodic stimulus with corresponding frequency.

An exocortex (speculative) is an external information processing system that augments, in a subtle and seamless fashion via a brain-computer interface, the brain's biological high-level cognitive processes.

BERLIN BRAIN COMPUTER INTERFACE(BBCI)

GRAZ BRAIN COMPUTER INTERFACE(GBCI)

BRAINGATE

BCI2000

In case of Invasive BCI there is a risk of formation of scar tissue.

There is a need of extensive training before user can use techniques like EEG

BCI techniques still require much enhancement before they can be used by users as they are slow.

Ethical implications of BCI will arise in future

BCI techniques are costly. It requires a lot of money to set up the BCI environment.