Monitoring Methods; Fetal Heart Rate; Internal Method, Direct Fetal Electrocardiogram (Fecg); Maternal Uterine Activity - GE Corometrics 170 Series Operator's Manual

Monitoring Methods

Fetal Heart Rate

External Method, Pulsed Doppler Ultrasound

Internal Method, Direct Fetal Electrocardiogram (FECG)

Maternal Uterine Activity

External Method, Tocotransducer (TOCO)

Internal Method, Intrauterine Pressure Catheter and Strain Gauge (IUP)

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Introduction: Monitoring Methods
The following is a summary of all the clinical monitoring methods found in the 170
Series. Refer to "'Preface, Overview"
to your monitor.
Ultrasound monitoring is available on all 170 Series Monitors. Models 171 and 173
provide a single ultrasound channel, while Models 172 and 174 provide two
ultrasound channels.
Fetal heart rate can be measured externally using pulsed Doppler Ultrasound. A
transducer placed on the mother's abdomen is used to direct an ultrasonic beam
toward the fetal heart and to sense Doppler shifted echoes created by moving cardiac
structures. A patented autocorrelation process is used to determine the timing of
successive cardiac cycles. The resulting fetal heart rate (FHR) pattern is recorded on
the strip chart paper and the FHR appears on the digital display.
FECG is available on Models 173 and 174 only. The Model 173 provides a
dedicated FECG connector. The Model 174 provides a combi-connector which can
be used for either FECG or US.
FECG signals are obtained via a spiral electrode attached to the fetal presenting part.
FHR is computed on a beat-to-beat basis using the R-to-R time interval of the QRS
complexes. The instantaneous FHR pattern is printed on the strip chart paper and
the FHR appears on the digital display.
Maternal uterine activity is measured externally using a tocotransducer (toco).
Relative pressure within the uterus is measured using a tocotransducer attached to
the mother's abdomen in the area of the uterine fundus. The readings are plotted on
the strip chart paper in a relative scale from 0 to 100 as well as shown on the digital
display. All 170 Series Monitors provide external uterine activity monitoring.
IUP is available on Models 173 and 174 only.
Intrauterine pressure is measured using a transcervical catheter. The pressure trend
is plotted over the range of 0 to 100 mmHg and the readings appear on the digital
display.
170 Series Monitor
2003023-001
for information about which modalities apply
Revision D