Adaptive Brain Interfaces (ABI) is a part of European Union
Information Technology’s ESPRIT program, with the central aim of extending
the capabilities of physically-impaired people to access new services and
opportunities. The ABI is a portable brain-computer interface based on the
analysis of electroencephalogram (EEG) signals and interface of P300 based
speller.
A cap with a few integrated electrodes
acquires brain signals that are pre-processed and sent to a computer for
further analysis. The portable brain interface has an embedded neural network
classifier that recognizes what mental task the wearer is concentrating on. It
does so by analyzing continuous variations of EEG signals over several cortical
areas of the brain. Each mental task is associated to a simple command. This
enables people to communicate using their brain activity, as the interface only
requires users to be conscious of their thoughts and to concentrate
sufficiently on the mental expression of the commands required to carry out the
desired task. So, by composing command sequences (thoughts), the user can read
a web page, interact with games, turn on appliances, or even guide a
wheelchair.
Brain interface will
be most successful when it is adapted to its owner. The approach is based on a
mutual learning process where the user and the ABI interface are coupled
together and adapt to each other. The neural network has been specifically
designed to cope with the challenging problem of recognizing mental tasks from
spontaneous on-line EEG signals. Although the immediate application of ABI is
to help physically disabled or impaired people by increasing their independence
and facilitating access to the Information Society, the benefits of such a
system are extensive. Anyone can use it for other purposes, e.g. health and
safety concerns (e.g. monitoring a person's level of alertness). ABI could also
contribute to the medical diagnosis of brain disorders.
This report presents a subject-independent
EEG(Electroencephalogram) classification technique and its application to a
P300 based word speller. It also presents use of signals recorded
from the brain to operate robotic or prosthetic devices. Both invasive and
noninvasive approaches have proven effective. Achieving the speed, accuracy,
and reliability necessary for real-world applications.
INTRODUCTION
Adaptive Brain Interface (ABI) is a human computer
interface system that accepts voluntary commands directly from the brain to
interact with the surrounding environment or to do a particular task. Sometimes it is
called a direct neural interface, Brain computer interface or a brain-machine
interface. It is a direct
communication pathway between a brain and an external device. BCIs were aimed
at assisting, augmenting or repairing human cognitive or sensory-motor
functions. The approach, on which the ABI is based, as the name implies, is the
adaptiveness. That means that both the system and the user adapt to each
other as explained before. In ABI the adaptive part is the local neural classifier
which is responsible for classifying input signal, and the user adapts by
training in the chosen mental tasks which he/she finds most comfortable and
effective to use. Second important approach is that this system should also
work reliably outside laboratory environment, i.e. in normal everyday life.
This calls for an easy to use, wearable (small and light) system.When compared
with other BCIs, one of the ABI’s areas of good performance is the time
required for training. User can acquire good control over the system just in
five days.
Each
mental task is associated to a simple command such as "select right
item". This enables people to communicate using their brain activity, as
the interface only requires users to be conscious of their thoughts and to
concentrate sufficiently on the mental expression of the commands required to
carry out the desired task. So, by composing command sequences (thoughts), the
user can read a web page, interact with games, turn on appliances, or even
guide a wheelchair. For example, the interface can be used to select letters
from a virtual keyboard on a computer screen and write a message. The ABI project
seeks to develop individual brain interfaces. The same system is not suitable
for everybody, as no two people are identical, either physically or
psychologically. This means that an interface will be most successful when it
is adapted to its owner. The approach is based on a mutual learning process
where the user and the ABI interface are coupled together and adapt to each
other.
