The Institute - June 2020 - TI10

A patient
wearing
the Argus II
eyeglasses,
which includes
a miniature
camera
that captures
what is in front
of the wearer

FINDING INSPIRATION

Two research projects that experimented
with electrodes inspired the technology
behind the Argus II.
While investigating how technology
could help improve his grandmother's
vision, Humayun discovered research
that was being conducted into the causes
of epileptic seizures. Physicians were
stimulating the patient's occipital lobe-
the brain's vision center-with electrodes,
hoping to determine whether that part
of the brain caused seizures.
"When the surgeon touched the occipital lobe, the patient would see a spot of
light even though there was no light,"
Humayun says. "That discovery made
me think: Could electrical stimulation
be used to restore eyesight?"
During the same period, another innovation was being developed: cochlear
implants, surgically implanted electronic
devices that provide a sense of sound to
people who are deaf or severely hard of
hearing. The implants use electrodes to
stimulate the auditory nerve.
The Argus II is not able to restore full
vision, but it can offer a person some
functional sight-the ability to see
boundaries and outlines of objects and
people-which can help them navigate
their environment.

HELPING PATIENTS SEE

The Argus II is made up of wearable
components and an implant. The device,
which bypasses the light-sensing cells in
TI-10

JUN 2020

THE INSTITUTE

the eye, can be used by patients age 25
and older who don't have damaged optic
nerves. If an optic nerve is damaged, as
occurs with glaucoma and other conditions, the implant can't stimulate it.
The implant includes a receiving
coil; an antenna, which is placed under
the muscles around the eye; and a
60-electrode array. The array is surgically placed in the back of the patient's
eye, connecting it to the retina's remaining neurons. It sends information to the
brain's visual center via the optic nerve.
To create information the implant can
use, the patient wears eyeglasses containing a miniature camera, which captures video of the scene in front of the
wearer. That information is then sent
wirelessly to a processor, which is about
the size of a cellphone and can be worn
on a belt or carried in a pocket.
The processor converts the video into
instructions that are sent wirelessly to
the implant. The implant's electrodes
then stimulate the retina, allowing the
patient to decipher the image the camera captured as flashes of light.
"The electrode array electrically stimulates and jump-starts the otherwise
blind eye," Humayun says.
Each patient meets with an occupational therapist or low-vision therapist
to relearn how to function with sight.
Patients also are required to return periodically to their ophthalmologist to get -JOANNA GOODRICH
the software and the system's electronics This article originally appeared online as
adjusted to meet their changing needs. "Mark Humanyun Builds Bionic Eyes."

LINDSEY BAUMAN/THE HUTCHINSON NEWS/AP

OVERCOMING CHALLENGES

When Humayun and his team first began
the Argus project, they had to resolve
several issues with hardware and software. How, they wondered, do you
make a device that doesn't deteriorate
in the eye? And what kind of electrical
pulses could be viewed as an image?
After working on the device for more
than 15 years, the team began clinical trials
in 2007, testing the technology on patients
for 30 minutes without implanting it.
"Witnessing the first patient, who had
been blind for 50 years, see a spot of light
for the first time was a defining moment
for me and the project," Humayun says.
After news spread that the test was successful, more engineers, physicians, and
scientists sought to join Humayun's team,
which now includes more than 200 people.
Humayun says his IEEE membership
helped him raise awareness of his work.
"The organization helped me connect
with engineers from many different
fields," he says, "such as biomedical,
electrical, industrial, and mechanical."
Two IEEE Fellows who joined Humayun's
team were instrumental in its success:
Gianluca Lazzi and James Weiland. Lazzi
is an engineering professor at USC who
specializes in antennas and wireless
communication. Weiland is a professor
of bioengineering and ophthalmology at
the University of Michigan in Ann Arbor.
"Mark has accomplished extraordinary
things at the intersection of engineering
and medicine in his career," Lazzi says.
"His pioneering contributions to the field
of artificial sight are so unique, fundamental, and visionary that they have created a paradigm shift in entire fields. I am
incredibly excited about what lies ahead."

https://viterbi.usc.edu/directory/faculty/Lazzi/Gianluca https://robotics.umich.edu/profile/james-weiland/ https://www.umich.edu/

The Institute - June 2020

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