HANDBOOK (V
4.0)
COMPLETE CONTROL SYSTEM GEN2
16
PLACING AND CONNECTING COAPT DOME ELECTRODES
If you’ve performed the discussion and palpation steps of the
Electrode Site Planning for Coapt pattern recognition, you will
have a good idea of the underlying muscle “areas of interest”
on your user’s residual limb. Perhaps you’ve even made a
series of temporary markings on their limb or taken some
pictures for planning.
Now you are ready to place the electrodes in the socket/liner
interface. This section will guide you if this is your first Coapt
fitting and provide useful tips if you’re already a pro.
A few very important things to know before you get started:
•
Electrode contacts with a Coapt system are solid Stainless-Steel Dome Electrodes. Each one will be
connected to a wired lead of a Coapt cable harness as described below.
•
Two Dome Electrodes work together to create one “channel” of EMG information.
o
If you picture an imaginary oval encircling the two placed Dome Electrode contact points, this is
the general region the EMG channel data will be from. The farther apart the pair of Dome
Electrodes, the larger (and deeper) the sensed area will be. Conversely, Dome Electrodes close to
each other will detect a more focused channel of EMG.
•
The Coapt system has 8 EMG channels (16 Dome Electrode contact points) and one ground/reference
contact (17 Dome Electrode contact points in total).
•
In some space-constrained fittings, the 17 Coapt Dome Electrodes can be reduced to as few as 9, by way
of contact-sharing (see below for details).
The most important thing to remember with electrodes:
Dome Electrodes MUST MAKE CONTACT WITH THE
SKIN
to work. Electrodes that do not stay in contact with the user’s skin will lead to serious prosthesis control
limitations. Take care in planning and be sure to fabricate a well-fitting interface for all fittings.
THE POSITIONING OF ELECTRODE CONTACTS SHOULD:
1.
Cover the areas of interest discovered during Palpation.
2.
Plan accordingly for socket/liner constraints.
