OXITEST PLUS 7 OPERATING MANUAL
!
detection of a resistance at the Nellcor Port when a Nellcor-compatible oximeter selected
from the menu does not make use of the Nellcor "R-Curves"; or
!
the signal STATUS is something other than "
NO SIGNAL
"
For any of the above conditions, the following message is displayed for as long as the sensor
remains connected to the Nellcor Port:
ERROR:Sensor R-Curve
selection disallowed
The Nellcor Port is also sampled in Auto and Alarm Test modes, and the same rules apply for
allowable selection of the Nellcor "R-Curve" as with Manual Mode. However, as the pulse oximeter
name is not displayed on the LCD in Auto and Alarm Test modes, no indication is given that an
alternate "R-Curve" is currently in use. Note that the LCD will still display the process of selecting
the curve (via the "RCAL OK!" messages, etc.).
3.14 ECG Trigger Output
Some pulse oximeters provide an input for a high level ECG signal, such as may be output by a
patient monitor. Such oximeters use the QRS complex of the ECG to synchronize and validate data
acquisition from the oximeter sensor, thereby improving signal-to-noise ratio under conditions of
low perfusion or motion artifact. On Nellcor oximeters (e.g. models N-200 and up), this feature is
called “C-LOCK”.
Oxitest Plus 7
provides an ECG Trigger output signal which may be used to test the Nellcor C-
LOCK function and similar capabilities on other oximeters (e.g. Nonin 8800). The ECG
TRIGGER signal is not a simulated ECG waveform, but simply a logic pulse of width and timing
comparable to the QRS, which is appropriate for triggering the pulse oximeter.
The ECG TRIGGER pulse is output from a 3.5 mm miniature mono phono jack located on the
right panel as indicated in
Figure 2
. The sleeve is grounded, and the tip is the trigger signal.
The
Oxitest Plus 7
ECG TRIGGER output is intended to drive high impedance loads, and will
deliver 2.5 volts into a 10K ohm load. This is optimal for driving the Nellcor N-200 via the ECG
IN/OUT interface, a 2.5 mm sub-miniature mono phono jack located on the rear panel of the
oximeter.
Refer to the manufacturer’s Service Manual for the pulse oximeter when interfacing the ECG input
of the unit under test to the
Oxitest Plus 7
ECG TRIGGER output.
Operation/Chapter 3
#
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