Medical Design Briefs - November 2021 - 37

" The major advantage of this system
to the user, compared to what currently
exists, is that it is soft and comfortable to
wear, and doesn't have any wires, " says
Yeo, associate professor on the George
W. Woodruff School of Mechanical
Engineering.
BMI systems are a rehabilitation technology
that analyzes a person's brain signals
and translates that neural activity
into commands, turning intentions into
actions. The most common noninvasive
method for acquiring those signals is
electroencephalography (EEG), which
typically requires a cumbersome electrode
skull cap and a tangled web of
wires.
These devices generally rely heavily
on gels and pastes to help maintain skin
contact, require extensive setup times,
are generally inconvenient, and are
uncomfortable to use. The devices also
often suffer from poor signal acquisition
due to material degradation or
motion artifacts - the ancillary " noise "
that may be caused by something like
teeth grinding or eye blinking. This
noise shows up in brain-data and must
be filtered out.
The portable EEG system Yeo
designed, integrating imperceptible
microneedle electrodes with soft wireless
circuits, offers improved signal
acquisition. Accurately measuring
those brain signals is critical to determining
what actions a user wants to
perform, so the team integrated a powerful
machine learning algorithm and
virtual reality component to address
that challenge. The new system was
tested with four human subjects but
hasn't been studied with disabled individuals
yet.
" This is just a first demonstration, but
we're thrilled with what we have seen, "
notes Yeo, director of Georgia Tech's
Center for Human-Centric Interfaces
and Engineering under the Institute
for Electronics and Nanotechnology,
and a member of the Petit Institute for
Bioengineering and Bioscience.
■ New Paradigm
Yeo's team originally introduced a
soft, wearable EEG brain-machine interface
in a 2019 study published in the
Nature Machine Intelligence. The lead
author of that work, Musa Mahmood,
was also the lead author of the team's
new research paper.
" This new brain-machine interface
uses an entirely different paradigm,
Medical Design Briefs, November 2021
Cov
This system is soft and comfortable to wear and doesn't have any wires. (Credit: Advanced
Science/Georgia Tech)
www.medicaldesignbriefs.com
ToC
37
involving imagined motor actions, such
as grasping with either hand, which frees
the subject from having to look at too
much stimuli, " says Mahmood, a PhD
student in Yeo's lab.
In the 2021 study, users demonstrated
accurate control of virtual reality
exercises using their thoughts - their
motor imagery. The visual cues
enhance the process for both the user
Researchers led by the lab of Woon-Hong Yeo at the Georgia Institute of Technology combined wireless
soft scalp electronics and virtual reality in a BMI system. (Credit: Georgia Tech)

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Medical Design Briefs - November 2021

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