The science of being able to
provide an artificial substitute for the limbs is
one of the most important around. This is because
it deals with parts of the body that are needed
for a normal life. Imagine being without a full
set of limbs - you won't have that much
confidence, would you?
This branch of biomedical
engineering is an extremely old one, with records
of attempts at it since about 45,000 years ago.
It arises from Man's primal ways of war, where
injuries often result in amputation (echoes of
Early prosthetics are just
like those in pirate movies - mere stumps for the
legs, and hooks for arms. They do, however served
to provide some functional use for what was left
of the limb. Amputees were able to walk, and
manipulate objects, but they often suffered from
The big push for development
in prosthetics came during the two World Wars.
Governments on both sides of the Atlantic found
themselves with tens of thousands of amputee
veterans. A great wave of sympathy brought about
the founding of what is now called the American
Orthotics and Prosthetics Association or A.O.P.A.
With that, and advances in
technology, prosthetics became more specific to
the user, and more comfortable to use. Plastic
resin was used to configure legs to individual
users, and simple joints and attachments enabled
some flexibility and control.
Current technology is based
on myoelectric technology, which was developed
during the 1970s. It involves using the small
impulses from the person's nerves to operate
[servos], and enable movement. This way, an amputee
is able to operate the arm just as he would with
a natural one.
[Myoelectric] arms these days
have reaction times that are as fast as the limbs
they replace. They also come with synthetic skin,
for cosmetic purposes, and temperature and touch
sensors, so as to give the user the use of some
of his senses.
Current work is being done
on myoelectric legs and feet which would allow
the user not only to walk, and do a slow jog, but
also experience the pressure under the feet as
With such rapid advances in
technology, it won't be long before myoelectrics
and normal limbs become indistinguishable.