Covidien Nellcor GR101704, Service Manual

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System Features
Service Manual 3-9
Second SpO
2
Event
Consider the second event. Suppose the SatSeconds alarm limit is still set to
25. The patient’s SpO
2
drops to 84% and the duration of the event is 15
seconds before saturation again exceeds the lower alarm threshold of 85%.
Because the SatSeconds alarm limit is set to 25 and the actual number of
SatSeconds equals 15, there is no audible alarm.
Figure 3-5. Second SpO
2
Event: No SatSeconds Alarm
1% drop below the lower alarm limit threshold
x15 second duration below the lower threshold
15 SatSeconds ; no alarm