sat on a wall;
had a great fall.
All the King's
And all the
Humpty together again!
of prosthetics is encouraging. There is a new prosthetic arm, “Proto
1,” which provides sensory
feedback and has eight degrees of freedom - much greater control than present
in today’s prostheses. It relies on a Targeted Muscle Reinnervation
technique (TMR), pioneered by Dr. Todd Kuiken. It involves the transfer
of residual nerves from the amputated arm to unused muscle regions close
to the injury, like the chest. Proto 1 is able to reposition the
thumb to make many different grips that is very useful for many common
tasks. It can also bend at the elbow, rotate at the shoulder and
wrist, and clench and unclench its fist.
already prototypes where neural controls allow people to move prostheses
through thoughts. These were first tested on monkeys where microelectrodes
implanted in the primary motor cortex enabled them to use neural activity
to control a prosthetic arm.
DARPA has developed a second thought controlled, mechanical prototype arm
called “Proto 2.” The arm is complete with a hand and fingers,
which can perform 25 of the 30 joint motions that a regular arm can.
Scientists are testing sensory feedback from Injectable MyoElectric Sensors,
injectable or surgically implanted devices that can measure muscle activity
rather than having to depend on surface electrodes.
program of DARPA’s is led by the Applied Physics Laboratory of John Hopkins
University and involves technology which will allow the next generation
of prosthetics to feel and manipulate objects naturally. Another
program led by Oakridge National Laboratory involves a new technology called
mesofluidics. This technology may allow prosthetic fingers, thumbs, wrists,
elbows, and shoulder joints to work as well as any natural limb by using
1 inch high pumps driven by tiny motors that compress and displace mineral
oil or other fluids. A prototype finger that has 20 pounds of pinch force
is currently being developed.
Work is being
done on an artificial skin which can measure force as small as 0.1 Newtons.
It will be made
of polyimide, a rubbery polymer with tiny carbon nanotubes embedded in
it. It is flexible, lightweight, and can generate electricity in
response to pressure. The nanotubes can also conduct heat from the surface
to temperature sensors in the polymer. By redirecting the nerves
in the arm to the chest muscles, the patients can sense touch, temperature,
and pain on the chest as if it were on the hand.
a prototype prosthetic exoskeleton called, “Robot Suit Hybrid Assistive
Limb,” designed by a company called CYBERDYNE, Inc. The suit they
have created increases strength, keeps the body active, and works as a
whole prosthetic limb. This suit, unlike those exampled in movies
is sleek and less clunky, but still has all the same functions. The next
step is to design a prosthetic exoskeleton using nanotechnology so that
motors, pumps, and sensors are not protruding.
are going to be the future building blocks for newer prostheses. There
are many advances that must be accomplished to reach the goal of a truly,
natural bionic arm. The technology to shrink the pumps, motors, sensors,
and batteries needs to improve so that they do not weigh down the prostheses
and make them unwieldy. Motors need to be more efficient. An
artificial skin that functions wholly like natural skin is on the horizon.
And most importantly the cost of nanotechnology needs to come down to make
the newer prostheses economical. Hopefully, we can lend a H.A.N.D.