Abstract:
Prosthetic socket liners provide both suspension and stability, and they do so best when they
cover the remaining limb without breaks in the liner surface. This full coverage conflicts with
the need to acquire myoelectric signals directly from the skin. Early solutions to this problem
include windows in the liner and metal electrodes piercing and thereby weakening the liner.
Windows compromise the integrity of the liner and often lead to discomfort at the edge of the
window. Metal electrodes require attachment of external wires after donning. Another
alternative is to mount cased electrodes in molded silicone receptacles. This may result in a
proper seal, but it requires repeated removal of the electrode from the liner.
The problems identified above can be addressed by passing the myoelectric signals directly
though the liner with flexible Conductive Inserts. This approach allows metal electrodes in the
outer socket to acquire the myoelectric signals as if they were in direct contact with the skin with
no wires attached to the liner. LTI has developed Conductive Inserts that not only pass
myoelectric signals through the liner but also allow for misalignment when the liner is inserted
into the socket. These Inserts can be installed by prosthetic technicians in a commercial liner, or
they can be built into a custom liner. With Inserts installed, a liner is a separate part that can be
easily removed for cleaning.
