Biomedical Engineering Reference
In-Depth Information
1.5.1 Prosthetics
Prosthetics are one of the oldest innovations of biomedical engineering. The assistive
technology field, prosthetics especially, became a true engineering discipline in itself in
the period following World War II, when an unprecedented number of veterans returned
home alive, but disabled, due to advances in medicine.
Prosthetics are defined as any “internal or external device(s) that
lost parts or
functions of the neuroskeletomotor system” and may be either orthopedic or externally
controlled. Externally controlled devices may be powered by the body itself through myo-
electricity or a separate power supply. Neural prosthetics represent the newest field in
prosthetics and one of the fastest-developing topics in biomedical engineering today.
replace
Orthopedic Prosthetics
In designing a “replacement” limb for the human body, an engineer is buried under
an obscene amount of considerations and design constraints. The appendage must be func-
tionally sufficient, a design unique to each individual, depending on the activities to be
accomplished. It must be comfortable, aesthetically pleasing, convenient, and simple in
attachment. Prosthetics and orthoses seeking to imitate the human body piece by piece
tend to have a great amount of difficulty in development and implementation. Instead,
the general application of the device should always be considered, with the user in mind.
An example of this design strategy can be found in the flex foot, a prosthetic foot with
no real resemblance to the natural appendage. Instead of struggling to recreate the bio-
mechanics of the ankle, tarsals, metatarsals, and phalanges of the lower leg, designers
created a prosthetic with a single contact piece, no joint, and consisting of only one mate-
rial. The Cheetah Leg shown in Figure 1.11, is one type of such a prosthetic and has
FIGURE 1.11
Paralympic sprinter Oscar Pistorius with a prosthetic leg. Designing for overall function, as opposed
to mirroring the human body, is often the more practical approach.
Compliments of http://www.thefinalsprint.com/
images/2008/05/oscar-pistorius-double-amputee-sprinter.jpg.
