User Manual

SKIN PREPARATION AND LEAD PLACEMENT
44 PatientNet Operator’s Manual, v1.04, 10001001-00X, Draft
All information contained herein is subject to the rights and restrictions on the title page.
For stable electrode contact:
1. Clean and dry skin
2. Remove excess hair
3. Buff the skin briskly
4. Attach snap to electrode before applying
5. Place close to bone or over soft tissue
6. Secure wires and transceiver
Preventing or Minimizing Motion Artifact
Understanding and practicing the following seven concepts will greatly reduce the
effect of motion artifact.
The electrical contact to the skin must be stable.
The electrical contact between the electrode and the skin involves three elements: (1)
the electrode sensing element, a silver chloride button, (2) the electrode gel, and (3)
the skin, which consists of the epidermis and the vascular layer immediately below the
epidermis. The epidermis is not a good conductor of electricity. Motion of the epider-
mis results in changes in electrical contact and a variable signal.
The best and most stable contact occurs when the electrode gel is in contact with the
vascular flow layer below the epidermis.
Changes in the electrode gel caused by wire or skin motion will, in turn, change the
electrical signal that is seen by the electrode button. These changes are minimized,
however, when the gel contacts the vascular layer of the skin rather than the epider-
mis. Buffing the skin increases contact with the vascular layer, therefore decreasing
signal variation. Use of a 2 x 2 gauze pad, towel, commercially available prep tape, or
other light abrasive to buff the site area will elevate the skin temperature, and bring the
vascular blood flow closer to the surface.
Place electrodes close to bone or over soft tissue.
Muscle motion produces electrical activity. If electrodes are placed over muscular
areas, such as the pectorals or oblique abdominals, they will detect this additional
electrical signal. Although the system is designed to detect some muscle activity, and
will recognize the QRS in the midst of muscle signal, some muscle activity and skin
motion can cause false arrhythmia calls.
Electrodes are disposable and applied only once.
Attempts to replace a loose electrode guarantees excessive motion artifact and results
in false alarms. If your electrodes contain soft gel, attach the snap onto the electrode
and then apply it to the patient, pressing down on the adhesive rim only
, so that the gel
remains confined. If your electrodes contain firm gel, attach the snap onto the elec-
trode, press down on the adhesive, and then press down on the center of the electrode
,
so that the gel is placed in direct contact with the skin.