Bionics
is the word Hollywood invented to explain
“The Six Million Dollar Man” in the 1970s.
It finally became respectable in the 1990s
as

sophisticated neural prosthetic devices,
such as cochlear implants for the deaf,
started to achieve real success with large
numbers of patients.
BIONs™
— injectable neurostimulation devices
about as big as a grain of rice — are Gerald
Loeb’s technology focus now. The devices
can transmit electrical signals into the
peripheral nervous system to help people
who suffer from a wide variety of neurological
conditions, such as paralysis or incontinence.
An M.D. and professor of biomedical
engineering in the USC Alfred Mann
Institute for Biomedical Engineering, Loeb
has been working on bionic devices for
many years.
“BIONs
are intended primarily for paralyzed
muscles, but there are many dysfunctions
that occur in people who have lost
the ability to control their muscles,” he
says. “The idea behind this technology is
to restore the electrical signals that are missing.”
During
the 1990s, Loeb worked with Advanced
Bionics Corp. in Sylmar, CA to commercialize
the first truly multichannel cochlear
implant. It was based on work he did
in the 1970s with a team at UC San Francisco.
Other neural prostheses are starting
to enter the market in the U.S., he says,
noting that biomedical devices typically have
long development cycles — at least five
to 10 years — before they can be commercialized.
Right
now, the BION is being used in research
to relieve complications of
stroke, such as
shoulder pain
and hand contractions. The
long-term goal
is to create functional movement
in a
paralyzed arm.
The tricky part
is building in
continuous control,
using sensors,
so that
the device will
be able to move
a limb relatively smoothly and continuously
rather than in spastic jerks.
“That
requires designing a pattern of
signals to stimulate the muscles continuously,
which means that we have to mimic
not just the electrical stimulation to activate
the muscle but the hundreds of sensors
that muscles normally have built into
them to send information back to the spinal
cord,” Loeb says.
A
daunting task, but Loeb is busy incorporating
movement sensors into the bionic
devices. The devices will transmit the
data to an external controller, which will
then adjust the level of stimulation, acting
just as the spinal cord and brain act
to adjust muscle activation in healthy people.