Medical Design Briefs - February 2021 - 24

Respirator 2.0: New N95-Alternative Introduces
Sensors for a Better Fit
The respirator earned a
100 percent success rate
for fit testing.
Brigham and Women's
Hospital, Boston, MA
Investigators from Brigham and
Women's Hospital and Massachusetts
Institute of Technology have been
working to design a better, reusable respirator that could serve as an alternative to an N95 respirator. In the latest
iteration of their work, they have introduced sensors to inform the user if the
respirator is on properly and whether
the filters are becoming saturated. The
team tested the respirator, known as the
transparent, elastomeric, adaptable,
long-lasting (TEAL) respirator, at the
Brigham and at Massachusetts General
Hospital (MGH), and reports a 100 percent success rate for fit testing among
40 participants, with feedback demonstrating exceptional fit, breathability,
and filter exchange. Results are published in ACS Pharmacology & Translational Science.
" During the COVID-19 pandemic, the
need for respirators and masks has been
urgent. Our team has worked to develop
a respirator platform that not only fits
comfortably and snugly but can also be
sterilized and re-sterilized, " says corresponding author Giovanni Traverso,
MB, BChir, PhD, a gastroenterologist
and biomedical engineer in the Division
of Gastroenterology at Brigham and
assistant professor in the department of
mechanical engineering at MIT. " In this
study, we looked at up to 100 resterilization cycles and found that the TEAL respirator we've designed can withstand
that. "
The team evaluated seven different
methods for repeatedly sterilizing the
TEAL respirator, including 100 cycles of
autoclaving, 100 cycles of microwaving,
prolonged exposure to UV treatment,
high heat (200 °C), 100 percent isopropyl alcohol, and bleach. The
researchers found minimal change to
the respirator's elasticity after repeated
sterilization.
The TEAL respirator is comprised of a
transparent, stretchy shell that can be
sterilized and filters that can be replaced
by the user. The team found that all par-

N95 alternative TEAL respirator with sensors. (Credit: Giancarlo Traverso)

ticipants could successfully replace their
filters, and most participants (90 percent) reported an excellent or good fit
for the respirator.
" TEAL is the first elastomeric respirator designed for use in a surgical setting,
preserving the sterile field and providing the user a comfortable, reusable personal protective equipment solution, "
says co-author Adam Wentworth, MS, a
senior research engineer in Brigham's
Division of Gastroenterology and the
Traverso lab.
The respirator's sensors can help
detect respiratory rate, exhalation temperature, and exhalation and inhalation
pressures. The team also added a thermochromic coating to the respirator -
a coating that changes color from black
to pink when the respirator is in direct
contact with a person's face and therefore has achieved a snug fit.
The researchers evaluated the respirator's performance in a clinical setting,
enrolling 47 subjects from Brigham and
MGH (40 of the subjects underwent fit
testing). Participants were asked to score
the respirator on its fit, breathability,
and ease of filter exchange, and they
were also asked whether they preferred
the TEAL respirator to other options. Of
those queried, 60 percent preferred the
TEAL respirator compared with 5 percent who preferred standard hospitalsupplied respirators. The remaining 35
percent had no preference.
" We were excited to receive the feedback from the trial participants that they

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would love to continue using and testing
the respirator, given its comfort, transparency, and ease of use, " says co-author
James Byrne, MD, PhD, a resident in the
department of radiation oncology at
Brigham and a postdoctoral fellow in
the Traverso lab.
Byrne notes that in addition to its
other features, the TEAL respirator's
transparency may offer some advantages
over more traditional respirators.
" One of the big benefits of the TEAL
respirator is that it enables visualization
of the lips, " he says. " This can be
immensely helpful in communication
and expression, especially during this
time when communication through
N95 respirators and surgical masks
makes it challenging to understand one
another. "
The sample size of the study was small,
and the investigators acknowledge the
importance of additional evaluation in a
larger cohort of individuals and over a
longer timeframe to further test the respirator's functionality. To use the respirator in a healthcare setting, additional
testing according to National Institute
for Occupational Safety and Health
(NIOSH) criteria will be needed.
Wentworth, Byrne, Traverso, and coauthors have filed multiple patents surrounding the respirator and sensors. In
addition, Wentworth, Byrne, and
Traverso have a financial interest in
TEAL Bio, a biotechnology company
focused on developing the next generation of personal protective equipment. A
Medical Design Briefs, February 2021

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Medical Design Briefs - February 2021

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