I'm an MIT professor,
but I do not design buildings or computer systems.
Rather, I build body parts:
bionic legs that augment human walking and running.
In 1982, I was in a mountain climbing accident,
and both of my legs had to be amputated due to tissue damage from frostbite.
Here you can see my legs:
24 censors, six microprocessors, and muscle-tendon-like actuators.
I'm basically a bunch of nuts and bolts from the knee down.
But with this advanced bionic technology,
I can skip, dance, and run.
Thank you.
(Applause)
I'm a bionic man, but I'm not yet a cyborg.
When I think about moving my legs,
neural signals from my central nervous system
pass through my nerves
and activate muscles within my residual limbs.
Artificial electrodes sense these signals,
and small computers in the bionic limb
decode my nerve pulses into my intended movement patterns.
Stated simply,
when I think about moving, that command is communicated
to the synthetic part of my body.
However, those computers can't input information into my nervous system.
When I touch and move my synthetic limbs,
I do not experience normal touch and movement sensations.
If I were a cyborg
and could feel my legs
via small computers inputting information into my nervous system,
it would fundamentally change, I believe, my relationship
to my synthetic body.
Today I can't feel my legs,
and because that, my legs are separate tools
from my mind and my body.
They're not part of me.
I believe that if I were a cyborg and could feel my legs,
they would become part of me, part of self.
At MIT, we're thinking about neural and body design.
In this design process,
the designer designs human flesh and bone,
the biological body itself
along with synthetics
to enhance the bidirectional communication
between the nervous system and the built world.
Neuron body design is a methodology to create cyborg function.
In this design process,
designers contemplate a future in which technology
no longer compromises separate,
lifeless tools from our minds and our bodies,
a future in which technology has been carefully integrated
within our nature,
a world in which what is biological and what is not,
what is human and what is not,
what is nature and what is not,
will be forever blurred.
That future will provide humanity new bodies.
Neuron body design will extend our nervous systems
into the synthetic world,
and the synthetic world into us,
fundamentally changing who we are.
By designing the biological body to better communicate
with the built design world,
humanity will end disability in this 21st century
and establish the scientific and technological basis
for human augmentation,
extending human capability beyond innate, physiological levels,
cognitively, emotionally, and physically.
There are many ways in which to build new bodies across scale,
from the biomolecular to the scale of tissues and organs.
Today, I want to talk about one area of neural and body design
in which the body's tissues
are manipulated and sculpted
using surgical and regenerative processes.
The current amputation paradigm hasn't changed fundamentally
since the US Civil War
and has grown obsolete in light of dramatic advancements
in actuators, control systems, and neural interfacing technologies.
A major deficiency is the lack of dynamic muscle interactions
for control and proprioception.
What is proprioception?
When you flex your ankle, muscles in the front of your leg contract,
simultaneously stressing muscles in the back of your leg.
The opposite happens when you extend your ankle.
Here, muscles in the back of your leg contract,
stretching muscles in the front.
When these muscles flex and extend,
biological sensors within the muscle tendons
send information through nerves to the brain.
This is how we're able to feel where our feet are without seeing them
with our eyes.
The current amputation paradigm breaks these dynamic muscle relationships,
and in so doing eliminates normal proprioceptive sensations.
Consequently, a standard artificial limb
cannot feed back information into the nervous system
about where the prosthesis is in space.
The patient therefore
cannot sense and feel the positions and movements of the prosthetic joint
without seeing it with their eyes.
My legs were amputated using a Civil War-era methodology.
I can feel my feet, I can feel them right now
as a phantom awareness,
but when I try to move them, I cannot.
It feels like they're stuck inside rigid ski boots.
To solve these problems at MIT,
we invented the Agonist-antagonist Myoneural Interface,
or AMI for short.
The AMI is a method to connect nerves within the residuum
to an external, bionic prosthesis.
How is the AMI designed, and how does it work?
The AMI comprises two muscles that are surgically connected,
an agonist linked to an antagonist.
When the agonist contracts upon electrical activation,
it stretches the antagonist.
This muscle dynamic interaction causes biological sensors
within the muscle tendon
to send information through the nerve to the central nervous system,
relating information on the muscle tendon's
length, speed and force.
This is how muscle tendon proprioception works,
and it's the primary way we, as humans,
can feel and sense the positions, movements and forces on our limbs.
When a limb is amputated, the surgeon connects these opposing muscles
within the residuum to create an AMI.
Now, multiple AMI constructs can be created
for the control and sensation of multiple prosthetic joints.
Artificial electrodes are then placed on each AMI muscle,
and small computers within the bionic limb
decode those signals
to control powerful motors on the bionic limb.
When the bionic limb moves,
the AMI muscles move back and forth,
sending signals through the nerve to the brain,
enabling a person wearing the prosthesis
to experience natural sensations
of positions and movements of the prosthesis.
Can these tissue design principles be used in an actual human being?
A few years ago, my good friend Jim Ewing
of 34 years reached out to me for help.
Jim was in an a terrible climbing accident.
He fell 50 feet in the Cayman Islands,
and his rope failed to catch him, hitting the ground's surface.
He suffered many, many injuries:
punctured lungs and many broken bones.
After his accident, he dreamed of returning to his chosen sport
of mountain climbing,
but how might this be possible?
The answer was Team Cyborg,
a team of surgeons, scientists and engineers
assembled at MIT to rebuild Jim back to his former climbing prowess.
Team member Dr. Matthew Carney amputated Jim's badly damaged leg
Brigham and Women's Hospital in Boston using the AMI surgical procedure.
Tendon pulleys were created and attached to Jim's tibia bone
to reconnect the opposing muscles.
The AMI procedure reestablished the neural link
between Jim's ankle-foot muscles and his brain.
When Jim moves his phantom limb,
the reconnected muscles move in dynamic pairs,
causing signals to pass through nerves of proprioception to the brain,
so Jim experiences normal sensations with ankle-foot positions and movements
even when blindfolded.
Here's Jim at the MIT laboratory after his surgeries.
We electrically linked Jim's AMI muscles
via the electrodes to a bionic limb,
and Jim quickly learned how to move the bionic limb
in four distinct ankle-foot movement directions.
We were excited by these results, but then Jim stood up,
and what occurred was truly remarkable.
All the natural biomechanics mediated by the central nervous system
emerged via the synthetic limb
as an involuntary, reflexive action.
All the intricacies of foot placement,
thank you, during stair ascent
(Applause)
emerged before our eyes.
Here's Jim descending steps,
reaching with his bionic toe to the next stair tread,
automatically exhibiting natural motions
without him even trying to move his limb.
Because Jim's central nervous system
is receiving the proprioceptive signals,
it knows exactly how to control the synthetic limb in a natural way.
Now, Jim moves and behaves as if the synthetic limb is part of him.
For example, one day in lab,
he accidentally stepped on a roll of electric tape.
Now, what do you do when something's stuck to your shoe?
You don't reach down like this. It's way too awkward.
Instead you shake it off,
and that's exactly what Jim did after being neurally connected to the limb
for just a few hours.
What was most interesting to me is what Jim was telling us
he was experiencing.
He said, "The robot became part of me."
Jim Ewing: The morning after the first time I was attached to the robot,
my daughter came downstairs
and asked me how it felt to be a cyborg,
and my answer was that I didn't feel like a cyborg.
I felt like I had my leg,
and it wasn't that I was attached to the robot
so much as the robot was attached to me,
and the robot became a part of me.
It became my leg pretty quickly.
Hugh Herr: Thank you.
(Applause)
By connecting Jim's nervous system bidirectionally
to his synthetic limb,
neurological embodiment was achieved.
I hypothesized that because Jim can think and move his synthetic limb,
and because he can feel those movements within his nervous system,
the prosthesis is no longer a separate tool
but an integral part of Jim,
an integral part of his body.
Because of this neurological embodiment,
Jim doesn't feel like a cyborg.
He feels like he just has his leg back,
that he has his body back.
Now I'm often asked when I'm going to be neurally linked
to my synthetic limbs bidirectionally,
when I'm going to become a a cyborg.
The truth is, I'm hesitant to become a cyborg.
Before my legs were amputated, I was a terrible student.
I got D's and often F's in school.
And then after my limbs were amputated,
I suddenly became an MIT professor.
(Laughter)
(Applause)
Now I'm worried that once I'm neurally connected to my legs once again,
my brain will remap back to its not-so-bright self.
But you know what, that's okay, because at MIT I already have tenure.
(Laughter) (Applause)
I believe the reach of neural and body design
will extend far beyond limb replacement
and will carry humanity
into realms that fundamentally redefine human potential.
In this 21st century,
designers will extend the nervous system
into powerfully strong exoskeletons
that humans can control and feel with their minds.
Muscles within the body can be reconfigured
for the control of powerful motors,
and to feel and sense exoskeletal movements,
augmenting humans' strength, jumping height, and running speed.
In this 21st century, I believe humans
will become superheroes.
Humans may also extend their bodies
into non-anthropomorphic structures, such as wings,
controlling and feeling each wing movement within the nervous system.
Leonardo da Vinci said, "When once you have tasted flight,
you will forever walk the earth with your eyes turned skyward,
for then you have been and there you will always long to return."
During the twilight years of this century,
I believe humans will be unrecognizable in morphology and dynamics
from what we are today.
Humanity will take flight and soar.
Jim Ewing fell to earth and was badly broken,
but his eyes turned skyward where he always longed to return.
After his accident, he not only dreamed to walk again,
but also to return to his chosen sport of mountain climbing.
At MIT, Team Cyborg built Jim a specialized limb for the vertical world,
a brain-controlled leg with full position and movement sensations.
Using this technology, Jim returned to the Cayman Islands,
the site of his accident,
rebuilt as a cyborg
to climb skyward once again.
(Crashing waves)
(Applause)
Thank you.
(Applause)
Ladies and gentlemen, Jim Ewing, the first cyborg rock climber.
(Applause)