Transcending Disabilities to Walk and to Dance
From: Medical Design Briefs - 05/2014 - page 4
By: Beth G. Sisk, Editor

Move over Iron Man: There's a new engineenng superhero who's part bionic,
able to change his height, and scale vertical rock and ice walls with a
simple change of leg prosthetics that he designed himself. Not only that, but
he designs bionic limbs for others, too.

Hugh Herr, PhD, an associate professor in MIT Media Lab's Biomechatronics
Group, who lost his lower limbs, uses a bionic foot and calf system called
the BiOM, which has been fitted to nearly 1,000 patients.

Herr gave an inspiring talk at the TED 2014 Conference in March about what
his and other laboratories around the world are developing in the field of
body-worn bionic devices.

"Electromechanics attached to the body and implanted inside the body are
beginning to bridge the gap between disability and ability, between human
limitation and human potential," Herr said. He explained that, at the time he
lost his legs, he realized the current technology was inadequate and that an
artificial limb could take on any form or function he wanted.

Bionics, he explained, entails the engineering of three extreme interfaces: -
mechanical, how the limb is attached; dynamic, how it can move; and
electrical, how it communicates with the nervous system.

In the future, he stated, prostheses will be designed using data-driven
quantitative frameworks for the mechanical interface. In his case, he
embedded sensors and smart materials into synthetic skins to attach the
bionic legs to his body. That was accomplished through a mathematical model
of his biological limb, along with MRI scans to determine the geometries and
locations of various tissues.

In the dynamic interface, at heel strike under computer control, the system
controls stuffiness to accommodate the shock of the limb hitting the ground.
At mid-stance, the bionic limb outputs high power to lift the person into the
walking stride.

The electrical interface uses sensors attached to the residual limb that
measure the electrical pulse of the muscles and communicate it to chips in
the bionic limb.

He ended with the story of Adrianne Haslet-Davis, a ballroom dancer, one of
the Boston Marathon bombing victims, who lost her left leg in the attack.

Collaborating with experts in prosthetics, robotics, machine learning, and
biomechanics, and over a 200-day research period studying how the body moves
in dance, the team used the data collected and embedded it into a bionic limb
for her.

"Bionics is not only about making people stronger and faster. Our expression,
our humanity can be embedded into electromechanics," he said, then brought
out Adrianne to dance her first public performance since the attack. As she
pivoted, spun, and twirled her way across the floor you could see on her face
how much the ability to dance again meant to her.

These innovations pull from nearly even facet of the device industry. Their
components, and the technologies to manufacture them, allow these wondrous
inventions to change people's lives.