breakthrough that allows people to control a robotic arm using only
their minds has been developed by researchers at the University of Minnesota. The research has the potential to help millions of people
who are paralyzed or have neurodegenerative diseases.
The study is published online today in Scientific Reports
, a Nature research journal.
‘The discovery could help millions of people who are paralyzed or have neurodegenerative diseases to control a robotic arm using only their minds.’
"This is the first time in the world that people can operate a
robotic arm to reach and grasp objects in a complex 3D environment using
only their thoughts without a brain implant," said Bin He, a University
of Minnesota biomedical engineering professor and lead researcher on
the study. "Just by imagining moving their arms, they were able to move
the robotic arm."
The noninvasive technique, called electroencephalography (EEG) based
brain-computer interface, records weak electrical activity of the
subjects' brain through a specialized, high-tech EEG cap fitted with 64
electrodes and converts the "thoughts" into action by advanced signal
processing and machine learning.
Eight healthy human subjects completed the experimental sessions of
the study wearing the EEG cap. Subjects gradually learned to imagine
moving their own arms without actually moving them to control a robotic
arm in 3D space. They started from learning to control a virtual cursor
on computer screen and then learned to control a robotic arm to reach
and grasp objects in fixed locations on a table. Eventually, they were
able to move the robotic arm to reach and grasp objects in random
locations on a table and move objects from the table to a three-layer
shelf by only thinking about these movements.
All eight subjects could control a robotic arm to pick up objects in
fixed locations with an average success rate above 80% and move
objects from the table onto the shelf with an average success rate above
"This is exciting as all subjects accomplished the tasks using a
completely noninvasive technique. We see a big potential for this
research to help people who are paralyzed or have neurodegenerative
diseases to become more independent without a need for surgical
implants," He said.
The researchers said the brain-computer interface technology works
due to the geography of the motor cortex--the area of the cerebrum that
governs movement. When humans move, or think about a movement, neurons
in the motor cortex produce tiny electric currents. Thinking about a
different movement activates a new assortment of neurons, a phenomenon
confirmed by cross-validation using functional MRI in He's previous
study. Sorting out these assortments using advanced signal processing
laid the groundwork for the brain-computer interface used by the
University of Minnesota researchers, He said.
The robotic arm research builds upon He's research published three
years ago in which subjects were able to fly a small quadcopter using
the noninvasive EEG technology. The research gained international media
"Three years ago, we weren't sure moving a more complex robotic arm
to grasp and move objects using this brain-computer interface technology
could even be achieved," He said. "We're happily surprised that it
worked with a high success rate and in a group of people."
He anticipates the next step of his research will be to further
develop this brain-computer interface technology realizing a
brain-controlled robotic prosthetic limb attached to a person's body or
examine how this technology could work with someone who has had a stroke
or is paralyzed.