Nellcor N-200 Operator's Manual page 41

Guide to Operation
Lost ECG Signal
If the ECG signal is lost or deteriorates to the extent that the
N-200 can no longer track it, the ECG LOST indicator flashes.
When the ECG signal is lost, oximetry measurements will
continue to be derived from the optical sensor signal. During
this time the N-200 continues to search for an ECG signal, and,
when it finds an adequate signal, C-LOCK ECG
synchronization again becomes active. To cancel the ECG
LOST indication, press the AUDIO ALARM OFF button.
When using C-LOCK ECG synchronization, either an
electrosurgical unit or significant upper-body muscular activity
may disrupt the ECG signal and cause the N-200 to begin
using the optical signal alone for obtaining measurements.
When an adequate ECG signal is again available, C-LOCK
ECG synchronization resumes functioning automatically.
Direct, Low-Level ECG Input
To use direct ECG input, position three conventional electrodes
in the standard limb lead configuration as illustrated in
Figure6.
When applying the electrodes, follow all appropriate
instructions and observe institutional standards. Direct ECG
capabilities conform to AAMI standards. For optimal
performance, position the RA (right arm) and LA (left arm)
electrodes below the lateral aspect of each clavicle. Position the
LL (left leg) electrode at the left costophrenic margin in the
mid-axillary line. Attach the lead wires to the electrodes, and
connect the lead wire pins to the ECG cable, observing correct
limb connections.
Finally, plug the ECG cable into the patient module's direct
ECG connection socket. This is a standard three-lead ECG
connector; a Nellcor-approved three-lead ECG cable should be
used.
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