Curiosity got the best of U.S. Marine Staff Sgt. James Sides. When approached with the opportunity to serve as the first est recipient of a new, innovative, and potentially beneficial
implantable myoelectric sensor (IMES) system for long-term use of
prosthetics, Sides knew it was a chance not to be missed.
Sides was injured in action when an improvised explosive device
detonated underneath him on July 15, 2012. He was on his second tour of
duty in Afghanistan. The explosion caused him to lose both his right hand
and the vision in his left eye. Doctors determined the best course of action
for his recovery involved taking half of his right forearm and fitting him for a
prosthetic. It proved to be a less-than-ideal solution for Sides. He struggled
to adapt to the prosthetic and was not thrilled with its performance as he
attempted even the simplest of everyday tasks and activities.
Months passed, and in early 2013, the Alfred Mann Foundation was
in need of a handful of individuals to receive, test, and provide feedback
on an experimental system designed to be the first minimally-invasive,
intuitive, multi-channel control system for prosthetics. The foundation
found its first willing and able subject in Sides.
“Being the first guy, I felt not like it was my duty, but it was an honor
to be a part of it,” he says. “I wanted to be the guy to help progress pros-
thetics, not just for disabled vets but for others.”
The potential of the IMES system was immediately evident to Sides.
Doctors expressed excitement and optimism that it had the potential to
help him perform his day-to-day activities with greater ease and more
effectiveness. The chance to improve his quality of life ultimately con-
vinced Sides to pursue the unique opportunity.
As a test subject, Sides was told the system would allow him to intuitively
operate three different prosthetic movements simultaneously: opening and
closing his hand, rotating his wrist, and moving his thumb. More importantly, these three key movements would combine to allow SSgt. Sides to have
better control over his prosthetic than he would get from more commonly-used body-powered prosthetics or motorized prosthetics. The IMES
system was also designed to address many of the shortcomings of current
myoelectric control systems. In some respects, their function is limited
because muscle signals are detected by electrodes placed on the surface
of the skin – sweat, movement between the electrode and the skin, and
limited access to only large muscles close to the surface of the skin. These
limitations make control non-intuitive, inconsistent, and unreliable. Not
so with the IMES system and its ability to allow Sides to operate three
prosthetic movements at the same time.
“The advantage of simultaneity is that the prosthetic operates more
like a natural hand than a linear, robotic limb,” says David Hankin, Chief
Executive Officer of the Alfred Mann Foundation.
How It Works
The IMES system works by utilizing electro-chemical signals in the
body that occur when a muscle contracts. Tiny IMES implants about 16
millimeters long and two millimeters wide are surgically placed into the
residual muscles in the patient's amputated limb. They serve to detect
22 April | 2014 | www.SurgicalProductsMag.com
by Mike Schmidt
“I wanted to be the guy to help progress
prosthetics, not just for disabled vets but
for others.” – U.S. Marine SSgt. James Sides