Welch Allyn CP 50 Directions For Use Manual page 42

38 Troubleshooting
Muscle tremor
Causes
• The patient is uncomfortable, tense, nervous.
• The patient is cold and shivering.
• The exam bed is too narrow or short to comfortably support arms and legs.
• The arm or leg electrode straps are too tight.
Actions
• Verify that the patient is comfortable, warm, and relaxed.
• Check all electrode contacts.
• If interference persists, turn the muscle-tremor filter on. If interference still persists,
the problem is probably electrical in nature. See the suggestions for reducing AC
interference (in a related troubleshooting tip).
AC interference
AC interference superimposes even-peaked, regular voltage on the waveforms.
Causes
• The patient or technician was touching an electrode during recording.
• The patient was touching a metal part of an exam table or bed.
• A lead wire, patient cable, or power cord are broken.
• Electrical devices in the immediate area, or lighting, or wiring concealed in walls or
floors are interfering.
• An electrical outlet is improperly grounded.
• The AC filter is turned off or set incorrectly.
Actions
• Verify that the patient is not touching any metal.
• Verify that the AC power cable is not touching the patient cable.
• Verify that the proper AC filter is selected.
• If interference persists, unplug the electrocardiograph from AC power and run it on
the battery. If this solves the problem, you'll know that the noise was introduced
through the power line.
• If interference still persists, the noise may be caused by other equipment in the
room or by poorly grounded power lines. Try moving to another room.
CP 50™ and CP 50 Plus™ 12-lead resting electrocardiograph