GE Corometrics 250cx Series, Operator'S Manual

Page: 67 / 250

Revision C 250cx Series Maternal/Fetal Monitor 5-3
2036946-001
Fetal Heart Rate Monitoring: Ultrasound (External Method)
Ultrasound (External Method)
NOTE:
Refer to the “Maternal/Fetal Monitoring, Clinical Applications Manual”
for patient application information.
Methodology
An ultrasound (
US
/US2) transducer placed on the maternal abdomen is used to
direct an ultrasonic beam toward the fetal heart; the transducer detects Doppler
shifted frequency changes in echoes created by moving cardiac structures. An
autocorrelation process is used to determine the time interval between successive
cardiac cycles.
The fetal heart rate is displayed in bpm and is continuously plotted on the strip chart
paper if the recorder is on. (Refer to the “US/US2 Setup Screen” figure below.) The
heartbeat indicator flashes for each detected heartbeat.
US/US2 Setup Screen
Select the
US
or
US2
softkey to access the
US
/
US2 Setup
screen below. The title of
the screen (
US
vs.
US2
) is dependent on the mode selected when the screen is
activated.
US/US2 Setup Screen
Volume
This field adjusts the volume for the FHR derived from the selected mode, US or
US2. This field works in conjunction with the front panel
Volume
buttons.
120
Exit
US
Volume:
US Setup
5
Volume 5 Alert: On
Trend
120
US2
20
IUP
FM Detect: Off Alert Suspend: Off
Applicable Spectra
alerts can appear in
this area