GE Corometrics 250cx Series, Руководство оператора

Страница: 155 / 250

Revision C 250cx Series Maternal/Fetal Monitor 13-3
2036946-001
Heartbeat Coincidence: Heartbeat Coincidence Theory
Heartbeat Coincidence Theory
The heartbeat coincidence feature alerts you when there is the possibility that you
may be monitoring a duplicate signal. Heartbeat coincidence is indicated when any
two heartbeats have a consistent phase relationship for equal to or greater than 60%
of the detected beats for about 60 seconds; the cessation of coincidence is indicated
when the phase relationship is inconsistent for greater than 40% of the detected
beats for about 7 seconds.
Heartbeat coincidence detection is most useful when monitoring twins but can also
detect when an elevated maternal heart rate is mistaken for a fetal heart rate.
NOTE:
The maternal heart rate derived from blood pressure readings is not used to
detect heartbeat coincidence since blood pressure is a static measurement.
The following table summarizes the combinations of heart rate sources that are
continuously compared for the possibility of coincidence.
Using the Heartbeat Coincidence Feature
Enabling/Disabling Heartbeat Coincidence Detection
This feature is enabled from the password-protected
Install Options
service mode
screen. Refer to the “250/250cx Series Monitor Service Manual” for detailed
information about enabling/disabling this feature.
Display Indicator
When heartbeat coincidence detection is enabled , the acronym
HBC
appears to the
right of the FHR2 mode title. (See “Heartbeat Coincidence Example” below.) If the
monitor detects two heartbeats that appear to be coinciding, this may indicate that
the two channels are picking up the same signal. When this coincidence occurs, the
heart rate numerics for
both heart rates display in inverse video, as shown below.
(Inverse video is a dark background with white numerics.) As soon as coincidence is
resolved, the numerics return to standard video. (Standard video is a white
background with dark numerics.)
Heartbeat Coincidence Comparisons
Mode
FECG US US2 MECG MSpO2
FECG
9 9 9 9
US
9 9 9 9
US2 9 9 9 9
MECG
9 9 9
MSpO
2
9 9 9