GE Corometrics 250cx Series, Service Manual, Page: 101 / 252

Revision C 250cx Series Maternal/Fetal Monitor 4-21
2036947-001
Maintenance: MECG Test
10. Repeat Step 9 for each of the following rates: 30, 120, 210, and 240 bpm.
11. Change the simulator’s
QRS Polarity
switch from + to –. Verify that the monitor
does not skip any beats.
12. Set the simulator’s
ECG Rate
switch to the RAMP setting. Verify that the
monitor’s MHR value counts between approximately 30 and 240 bpm and that
the recorder prints a ramp between the same values. (Refer to figure on “MECG
Ramp” on page 4-22.)
13. Set the simulator’s
ECG Rate
switch to the
Δ
15 position. Verify the following on
the monitor:
‹
The MHR value alternates between two rates 15 bpm apart on the recorder
printout.
‹
The MHR heartbeat indicator ( ) flashes for each input signal.
‹ The ECG “beep” is heard from the rear panel speaker; the volume can be
adjusted on the
MHR/P Setup
screen.
‹
The recorder prints an oscillation of 15 bpm between 110 and 125 bpm on
the top grid of the strip chart paper. (Refer to “MECG Oscillation” on
page 4-22.)
‹ Repeat Step 13 for rate values of
Δ
22 and
Δ
27. The results should be the
same except that the MHR value alternates between two rates 22 bpm or 27
bpm apart and the recorder prints an oscillation of 22 or 27 bpm. The top value
is always at approximately 125 bpm. (Refer to “MECG Oscillation” on
page 4-22.)
„
Set the simulator’s
ECG Rate
switch to the MANUAL position and the
Manual
Adjustment
knob to the counterclockwise position. Disconnect the ECG
simulator cable from the monitor’s y-adapter cable. Verify the following on the
monitor:
‹ The
MHR/P
value and
Pulse
mode are both blank.
‹
The recorder stops printing maternal heart rate data on the strip chart paper.
‹ The recorder prints the message
CARDIO INOP
on the center margin of the
Table 2. MECG Test Simulator Settings
Section Switch Setting
FECG/MECG
Rate/CMR RATE
Rate MANUAL
Mode MECG
QRS Amplitude 500 µV
QRS Polarity +
GENERAL Pattern Memory Off
UA
Main CMR
Mode TOCO