Brain-Computer Interface Helps
Paralysed Communicate
Scientists have developed a
brain-computer interface that reads the brain's blood oxygen levels and enables
communication by deciphering the thoughts of patients who are paralysed and
unable to talk. In a trial of the system in four patients with complete lockedin
syndrome -incapable of moving even their eyes to communicate -it helped them
use their thought waves to respond “yes or no“ to spoken questions.
People who are paralysed except
for up and down eye movements and blinking are classified as having locked-in
syndrome. If all eye movements are lost, the condition is referred to as
complete locked-in syndrome.
Researchers, leading this trial,
said the brain-computer interface (BCI), which is non-invasive, could transform
the lives of such patients, allowing them to express feelings and opinion to
their loved ones and carers.
Counter to expectations, the
researchers said, the patients reported being “happy“ despite their condition.
“The striking results overturn my own theory that people with complete locked-in
syndrome are not capable of communication,“ said NielsBirbaumer,aneuroscientist at Switzerland's Wyss Center for Bio and Neuroengineering, who co-led the study .
The trial, published in the
journal PLOS Biology on Tuesday , involved four patients with amyotrophic
lateral sclerosis (ALS) -a progressive motor neuron disease that destroys the
part of the nervo us system responsible for movement of human body .
The researchers asked personal
questions with known answers, such as, “Your husband's name is Joachim?“, and
open questions that needed yes or no answers, such as “Are you happy?“.
The BCI technique uses
technologies called near-infrared spectroscopy and electroencephalography (EEG)
to measure blood oxygenation and electrical activity in the brain. “The machine
records the blood flow... and calculates how (it) changes during “yes“ and
during “no“, and the computer develops an idea, a pattern,“ Birbaumer said.
“And after a while, we know what
the patient is thinking, when he thinks “yes“, or when he thinks “no“, and from
that we calculate the answer,“ he said.
The “known“ questions elicited
correct responses seven times out of 10, and the question “Are you happy?“
resulted in a consistent “yes“ response from the four people, repeated over
weeks of questioning. John Donoghue, director of the Wyss Center, welcomed the
work as “a crucial first step in the challenge to regain movement“ for
completely locked-in patients.
He said his team now planned to
build on these results to develop the technology further and eventually aim for
it to be available to people with paralysis resulting from amyotrophic lateral
sclerosis , stroke, or spinal cord injury .
Girl's dad rejects BF's marriage
proposal
A 61-year-old, known only as
Patient B, had lost use of every muscle to a neurological disease. He was one
of the three locked-in syndrome sufferers to benefit from the device that
enabled them to communicate via a device that measures oxygen in the brain. But
his ability to communicate again brought some disappointment. When his
daughter's boyfriend asked his permission to marry her, the patient responded
with a damning “no“. While the system is not consistently accurate, getting it
right about 70% of the time, the response to the proposal was “no“ nine times
and “yes“ just once, leaving little doubt it was a decisive rejection.
Source : TIMES OF INDIA-2nd February,2017
