GE Corometrics 250cx Series, Operator'S Manual

Page: 80 / 250

6-4 250cx Series Maternal/Fetal Monitor Revision C
2036946-001
Uterine Activity Monitoring: Tocotransducer (External Method)
Accounting for Belt Tension
When adjusting the belt on the patient, regardless of transducer type, it is important
to ensure a comfortable fit; also, ensure that the transducer is held securely in place.
GE Medical Systems
Information Technologies recommends adjusting the belt
tension so that, between contractions, the
UA
display shows approximately
25 mmHg (3.3 kPa) above the initial baseline.
After the belt is adjusted, it is important to establish a new baseline to prevent belt
tension to be counted as uterine pressure; also, pressure readings could tend to go off
the scale if belt pressure is not taken into account. Again, the
UA Reference
button
should only be pressed between contractions.
More About Referencing
Out of Range Condition
After you press the
UA Reference
button, if there is insufficient range to provide at least
100 mmHg (13.3 kPa) above the reference level (probably because the belt is too
tight), the
UA
display area flashes the message
CHECK TOCO
. If this happens, remove
the tocotransducer from the patient; re-reference with no pressure applied to the button;
reapply the transducer adjusting the belt to approximately 25 mmHg (3.3 kPa)
above
the baseline; then re-reference one more time. If you still receive the
CHECK TOCO
message, try a different tocotransducer or contact your GE Service Representative.
Manually Setting the Baseline at the Default Value
Briefly pressing the
UA Reference
button sets the baseline at the default setting—the
default is configured on the password-protected
Install Options
service screen. The
monitor is shipped from the factory with either a default setting of 10 in mmHg
mode or 1.3 in kPa mode. Qualified personnel can access the password-protected
Install Options
service screen to set the baseline default to
5, 10, 15, 20,
or 25 relative
units in mmHg mode or
0.7, 1.3, 2.0, 2.7,
or 3.3 in kPa mode. Refer to the “250/250cx
Series Monitor Service Manual” for more information.
Manually Overriding the Baseline Default Value
Pressing and holding the
UA Reference
button for more than 2 seconds causes the UA
reference level and display to override the default setting and cycle through all
available selections:
5, 10, 15, 20,
or 25 relative units in mmHg mode or
0.7, 1.3, 2.0,
2.7,
or in 3.3 kPa mode, starting at the default setting—until the button is released.
Once the button is released, the UA trace and UA value take on this new value as a
baseline for reference.
Briefly pressing the
UA Reference
button reverts back to using the default setting
configured via the password-protected
Install Options
service screen.
Automatic Baseline “Zeroing”
If pressure falls below 0 mmHg (0 kPa) (probably because the belt has loosened),
automatic UA referencing occurs and a new baseline reference is set at 0 relative
units.