78 August 2019 http://www.designworldonline.com DESIGN WORLDThe Robot Report
Developing ‘power steering’ for the arm
Cambridge, Mass.-based Myomo is
based on technology developed at the
Massachusetts Institute of Technology
and Harvard Medical School.
“A dozen years ago, we spun out of
MIT,” Gudonis told The Robot Report.
“Dr. Woodie Flowers was a pioneer
in powered prosthetics, and his lab
originally focused on amputees. However,
a pair of grad students said there was a
much larger group of people who could
be helped.”
Myomo uses sensors built into a
cuff that fits over the bicep and tricep
muscles. They detect electromyographic
(EMG) signals and activate motors to
move the arm at the elbow.
“Unlike implants in the brain, which
are still experimental, electromyogram
sensors sit in a device on the surface of
the skin,” said Gudonis. “In able-bodied
individuals, the muscle emits voltage
when activated, and there’s 100% signal
strength, but after a stroke or other injury,
the signals are attenuated.”
“The myoelectric orthosis, or powered
arm brace, detects the intention to
move as the muscle sends a micro EMG
signal,” he explained. “Onboard software
deciphers it, providing power steering for
the arm.”“The control unit on the side of the
brace has the battery and a circuit board
and sends control signals to two motors
at the elbow and hand,” Gudonis said.
Myomo’s technology can be liberating
for people using it, according to Gudonis.
“People can feed themselves, open doors,
and carry objects,” he said.Myomo makes software, hardware
refinements
There have been several improvements
over time, Gudonis said. “First is the
refinement of the software algorithms
and electromechanical interface,” he said.MyoPro enables people to
use both arms.| MyomoMyoPro can restore function for some people after years of disability.
| Myomo“Second, taking our original design and
making it a lightweight — 2.5 to 3 lb. —
custom-fabricated orthosis or brace,” said
Gudonis. “This takes it out of the clinic or
rehabilitation hospital, and it can be used
in the home or office.”
“Every few years, we bring out a new
revision,” he said. “MyoPro 2 has the added
ability to open and close hands. It has four
sensors, on the bicep, tricep, flexor, and
extensor, and it connects to a mobile app
with Bluetooth.”
“We’re working on finer motor controls
and lighter weight.” said Gudonis. “We use
small motors from Maxon, and the battery
is designed to be used all day. It can pop
out, and we provide a spare battery.”
A major hurdle for exoskeletons
and other wearable devices in the U.S.
has been reimbursement by insurance
providers. Myomo is working with
healthcare service providers.
“Our device is provided through
orthotics and prosthetics clinics and billed
to insurers,” Gudonis said. “The out-of-
pocket price to the user depends on the
his or her insurance plan, and it may be
just a few thousand dollars.”Reaching and training users
“This is really disruptive technology in the
rehabilitation industry,” claimed Gudonis.
“Prior solutions have been hands-on
therapy at the hospital or big stationary
machines in clinics, but nothing portable
that people can use at home.”DESIGN WORLD http://www.designworldonline.com August 2019 79Myomo_Robot Report 8-19_Vs5.LL.indd 78 8/5/19 12:44 PM