Biomedical Engineering Reference
In-Depth Information
FIGURE 10-21
Examples of the
Jaipur foot.
(Courtesy of
BMVSS, with
permission.)
More than 20,000 Jaipur feet are fitted from clinics in 21 countries annually, with total
fittings since its debut exceeding 350,000.
10.9
ACTIVE PROSTHETICS
An active prosthesis is one that uses an additional energy supply for motion and control
over and above that provided by muscle power from the user. These range from the
most complex, 20 DoF upper limb prosthetics currently under development to relatively
unsophisticated, single DoF knee joints and everything in between.
There are of course pros and cons of selecting an active prosthesis above a passive or
cosmetic one, as detailed in Table 10-3 (Kelley, Pangilinan et al., 2009).
The process of operating our arms and hands to perform even very complex functions
has been so well learned that it has become completely automatic and can often be done
while the brain is engaged in other activities. Consider, for example, drinking from a cup,
TABLE 10-3
Pros and Cons Relating to the Selection of Upper Limb Prosthesis Types
Type
Pros
Cons
Cosmetic
Lightest
High cost if custom made
Best cosmesis
Least function
Least harnessing
Body powered
Moderate cost
Most body movement needed to operate
Reasonably light
Most harnessing
Durable
Least satisfactory appearance
Good sensory feedback
Increased energy expenditure
Wide range of actuators for different activities
Battery powered
Moderate or no harnessing
Heaviest
Least body movement needed to operate
Most expensive
Moderate cosmesis
Most maintenance
More function-proximal areas
Limited sensory feedback
Stronger grasp in some cases
Extended therapy time for training
