Manufacture of a prosthesis
Prosthesis project:
Definition: a prosthesis is a device designed to compensate for the loss of
the whole or part of an organ or a limb.
How do we manufacture a device designed to compensate for the loss of
a limb.
The manufacture of a prosthesis requires not only technical skills
but also
artistic know-how.
Technical skills:
In order to make a good skinbone prosthesis we must
first of all take measurements.
It is necessary to determine the length and
circumference of the leg stump in order to
measure the overall size of the
stump.
The first thing to do is to wrap the stump with plaster bands so
as to make a mould.
Then we pour plaster in the mould to create a negative
of the stump.
We can now start making the prosthesis.
The leg stump
The time has now come to use the Eva foam rubber.
You heat it in an
oven until it becomes elastic enough to be applied to the mould
and
thereby adopt the form of the mould.
Eva foam rubber + P.V.A. bag + Knitted
fabric + resin (with a layer of brown paint
to imitate the
colour of the skin)
In order to protect the Eva foam rubber and to let the resin flow, the
whole thing is
covered with a plastic bag called a P.V.A. bag.
After that, 2 times four layers of knitted fabric is added and in the end
yet another
P.V.A. bag to protect the whole thing.
Below the skinbone prosthesis an articulation is fixed in order to adapt
the
skinbone to the foot.
The articulation enables the foot to move, bend, turn...
To fasten the prosthesis to the stump a strap is attached with screws
to
the sides of the prosthesis.
The manufacture of a prosthesis can take from 2 weeks to several months.
It all depends on the demands of the client and also on his or her
degree of collaboration. He or she needs to be present quite often to permit
the
perfect fitting and possible rectifications.
A good prosthesis can last a
lifetime. In Europe, however, prostheses are
renewed every year. It is all
a question of money. In Europe the social security system
reimburses the
costs. In Africa we are still far from that.
Many thanks to César Rwagasana who explained everything to me
in his
workshop at the Association « Afrique En Marche »
A bit of History
After the mechanic prosthesis way back in the 10th Century BC, where the
Egyptians
replaced a missing big toe by a wooden prosthesis to help the
patient to walk easier, the
21st Century will be the century of the functional
prosthesis commanded by the brain itself.
The discovery of new materials that are more resistant, light, flexible, well
tolerated
by the organism, enables the researchers to envisage the
substitution of a limb or
an organ and total control and command of its
movements by the brain.