Covidien Nellcor Operator's Manual page 34

Installation
A Sensor Message occurs when the device cannot obtain an SpO
pulse rate.

Note:
If the sensor is not connected firmly, the monitoring system could lose signal from
patient.

Note:
Physiological conditions, medical procedures, or external agents that may interfere
with the monitoring system's ability to detect and display measurements include
dysfunctional hemoglobin, arterial dyes, low perfusion, dark pigment, and externally
applied coloring agents, such as nail polish, dye, or pigmented cream.
24
level or a
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Operator's Manual