Gate is a brain implant system built by Cyberkinetics which
implements the technology Brain-computer interface (BCI).
interface (BCI) is a fast-growing emergent
technology, in which researchers aim to build a direct channel between
the human brain and the computer.
Brain Computer Interface (BCI) is a collaboration in which a brain
accepts and controls a mechanical device as a natural part of its
representation of the body.
is often called a mind-machine interface (MMI), or sometimes
called a direct neural interface(DNI) or a brain–machine interface (BMI)
Research on BCIs has been going on for more than 20
years, but from the mid-1990s there has been a
dramatic increase in working experimental implants.
Brain Gate system was commercially developed by
the bio-tech company Cyberkinetics in 2003 in
conjunction with the Department of Neuroscience at
First of all it was implemented on rats then monkeys
and after no complication on human beings
BCI RESEARCH ON
At first, rats were implanted
with BCI .
Signals recorded from the
cerebral cortex of rat operate
BCI to carry out the movement
Researchers at the University
of Pittsburgh had demonstrated
on a monkey that can feed itself
with a robotic arm simply by
using signals from its brain.
PRINCIPLE BEHIND BCI
sense, transmit, analyze the language of neurons
and translate it in to computer commands .
It consist of a sensor that is implanted in the
motor cortex of the brain and a device that
analyses brain signals. The signals generated by
brain are interpreted and translated into
It consists of a silicon array about the size of an
Aspirin tablet that contains about 100 electrodes
each thinner than a human hair.
Chip uses 100 hair-thin electrodes that detects the communication
between neurons in specific areas of the brain
INVASIVE AND SEMI INVASIN BCI
Invasive BCIs are implanted directly into the grey matter
present in the motor cortex of the brain during neurosurgery.
As they rest in the grey matter, invasive devices produce the
highest quality signals of all BCI devices.
But they are prone to scar- tissue buildup , causing the signal
to become weaker or even lost as the body reacts to a foreign
object in the brain.
Electrocorticography (ECoG) measures the electrical activity
of the brain taken from beneath the skull
The electrodes are embedded in a thin plastic pad that is
placed above the cortex, beneath the dura mater.
Electroencephalography (EEG), the recording is obtained by
placing electrodes on the scalp with a conductive gel or paste.
Usually recording is done after preparing the scalp area by light
abrasion to reduce impedance due to dead skin cells
Functional Magnetic Resonance Imaging (fMRI) exploits the
changes in the magnetic properties of hemoglobin which contains
Activation of a part of the brain increases oxygen levels there
increasing the ratio of oxyhemoglobin to deoxyhemoglobin.
Magnetoencephalography (MEG) detects the tiny magnetic fields
created as individual neurons "fire" within the brain.
It can pinpoint the active region with a millimeter, and can follow
the movement of brain activity .
Structure of HUMAN BRAIN
HOW BCI IMPLEMENTS?
A more difficult task is interpreting the brain signals for movement in
someone who can't physically move his own arm. With a task like
that, the subject must "train" to use the device.
With an implant in place, the subject would visualize closing his or
her disabled hand. After many trials, the software can learn to
recognize the signals associated with the thought of hand-closing.
Software connected to a robotic hand is programmed to receive the
"close hand" signal and interpret it to mean that the robotic hand
should close. At that point, when the subject thinks about closing the
hand, the signals are sent and the robotic hand closes.
BCI ON HUMAN
Over a period of nine
sustained a spinal cord injury
leading to paralysis in all four
limbs ) took part in 57 sessions.
During which the implanted
Brain Gate sensor recorded
activity in his motor cortex
region while he imagined
moving his paralyzed limbs and
then used that imagined motion
for several computer-based
tasks such as, moving a
computer cursor to open email,draw shapes and play
simple video games.
Provide disabled people with communication, environment
, control, and movement restoration.
Provide enhanced control of devices such as wheelchairs
,vehicles , or assistance robots for people with disabilities
This technology provides the ability to control a video game by
thought , ability to change TV channels with your mind etc.
Control robots that function in dangerous or inhospitable
At present the biggest obstacle of BCI technology is
the lack of sensor mode that provides safe, accurate,
and strong access to brain signals.
It is very expensive.
Processing and Information transformation of data is
very time taking.
Difficulty in adaptation and learning
The results of BCI are spectacular and almost
BCI can help paralyzed people to move by
controlling their own electric wheelchairs, to
communicate by using e-mail and Internet-based
phone systems, and to be independent by
controlling items such as televisions and electrical
Conclusively, BCI has proved to be a boon for
paralyzed patients and all human being in future.
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