One big, robotic foot and then the other; that's how a man wearing a
clunky-looking exoskeleton makes his way across the room. The machine's
motors are noisy and its movements are painfully slow, but these details
seem to fade into the background when you realize how the man is
controlling the cumbersome contraption: He's doing it with his mind.
The exoskeleton
— a robotic device that fits around the man's hips and legs — is part
of a new technology being developed by researchers in Germany and Korea.
The other part is a dark cap on the man's head, covered with electrodes
that facilitate the connection between his brain and the machine.
The man wearing the exoskeleton in the experiment can walk on his own
(he's one of the participants in the researchers' newly published
study), but the scientists think their new mind-controlled device could
one day be used by people who can't walk — such as those who have
suffered severe spinal cord injuries, or people with neurodegenerative
diseases, like amyotrophic lateral sclerosis (ALS). [Bionic Humans: Top 10 Technologies]
Lots of researchers are working to develop technologies that help people
regain control over their movements through a combination of robotics
and brainpower (formally known as brain-computer interface control
systems).
In 2011, a woman who suffered a stroke that left her unable to move lifted a cup with a robotic arm
that she manipulated with her thoughts. In 2012, another woman (this
one a quadriplegic suffering from spinocerebellar degeneration) doled
out a few high fives and ate a piece of chocolate using a similar, mind-controlled robotic arm.
But these technologies differ from the new brain-controlled
exoskeletonin a very important way: In order to manipulate either of
these robotic arms with their brains, the patients had to first undergo
invasive brain surgery. Surgeons implanted tiny electronics into the
patients' brain that, when connected to external wires, allowed the
women to control the robotic arms using electrical impulses from their brains.
But the brain-computer interface developed by researchers at Korea
University in Seoul, South Korea, and the Technical University (TU) of
Berlin doesn't require brain surgery. In order to control the
exoskeleton, study subjects first strap on the cap covered in small
electrodes that cling to their scalps. The skullcaps are the tools that
connect the subject's brain to the exoskeleton, the researchers said,
and are commonly used in electroencephalograms (EEGs)
— a method of recording electrical activity by placing conductive
materials on the scalp (the brain waves are then plotted on a chart,
much like heart rate).
In the exoskeleton study, the EEG cap was used to pick up very
particular brain signals — those created by what the researchers call
steady-state visual evoked potentials (SSVEPs). Essentially, the
electrodes detect "flashing lights," the researchers said.
A small controller jutting out from the exoskeleton holds a set of
light-emitting diodes (LEDs) that light up in different patterns. The
patterns represent specific commands that the exoskeleton can carry out,
such as stand up, sit down, walk forward, turn left and turn right. [Super-Intelligent Machines: 7 Robotic Futures]
The person wearing the exoskeleton stares at one of these lights (for
example, the one that corresponds to the command for taking a step
forward). His brain produces a particular electrical signal in response
to seeing the light. That signal is picked up by the electrode cap,
which sends the brain signal information to a computer via a wireless
connection. The computer then translates the brain signals into the
appropriate command and sends that command to the exoskeleton. Within a
few seconds, the exoskeleton takes a step forward.
The setup is "robust and intuitive," according to Klaus Müller, a
professor in the computer science department at TU and lead author of
the new paper outlining the research. The technology is considered
robust because the interface still works even though the exoskeleton
creates all kinds of electrical signals that could interfere with a
person's brain signals.
And it's intuitive because, despite all the steps involved in the
brain-controlled process, it's actually pretty simple to get the
exoskeleton to do what you want it to do, Müller told Live Science in an
email.
But the brain-computer interface is not without its quirks. For one
thing, all 12 participants in the study had to be screened for epilepsy
before participating, and even Müller said that staring at the
interface's flashing LEDs for extended periods of time gives him a
headache.
In the future, the researchers hope to create a similar system that
causes less "visual fatigue," Müller said. The other obstacle standing
in the exoskeleton's way is cost.
Not only do the researchers need to conduct all kinds of expensive
clinical studies before getting these devices anywhere near patients in
the real world, the patients themselves will then have to pay for them.
Getting insurance companies to cover the cost of this futuristic (but
potentially life-altering) tech could be the hardest part of the
process, Müller said.
0 comments:
Post a Comment