GE Corometrics 250cx Series, Operator'S Manual

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5-8 250cx Series Maternal/Fetal Monitor Revision C
2036946-001
Fetal Heart Rate Monitoring: Fetal Heart Rate Alarms
Sample Clinical Exceptions
The figure below provides an example of FHR fluctuations above and below the
high alarm limit setting.
Fluctuations Near High Alarm Limit Example
Whether the pattern shown in the above figure generates an alarm depends on what
percentage of the data violates the limit. The monitor evaluates the data on an on-
going basis; the methodology can be simplified as follows:
„
An FHR threshold alarm occurs if the FHR violates the alarm limit setting for
more time than it stays within the specified acceptable range.
„ The time-to-alarm increases as a greater percentage of data stays within the
specified acceptable range.
Signal Quality Alarms
A fetal heart rate signal quality alarm occurs if the monitor is unable to detect an
acceptable FHR signal.
Active Signal Quality Alarm
Signal quality alarms are indicated both visually and audibly. Dashes “– – –” display
in the affected fetal heart rate display. The audio alarm is described as alternating
high-low tones.
Resolved Signal Quality Alarm
As soon as an alarm condition is resolved, both the visual and audible indications
automatically disappear (unlatch).
FHR (bpm)
Time (minutes)
high alarm limit
(threshold)