In recent years much work has been done in many countries on
the development of powered artificial limbs for use by adults and
children with congenital deficiencies i.e. present at birth, and
by amputees.
The established methods of actuating these powered limbs are
either by pneumatic motors, operated from compressed carbon dioxide
or by electric motors. Some designs have also used hydraulic and
electro-hydraulic actuators.
In the development of the complete powered limb the following
problems have also to be considered:
(a). The design of the mechanical components and the
harness for attaching the appliance to the body.
(b). Control input units by means of which signals from
the wearer operate the powered limb. Control input
signals maybe either mechanical (bone movement) or
electrical.
(c). The control system mechanies, involving the type
of feedback which should be used. This can be either
visual feedback or sensory feedback from the forces
exerted by the appliance.