GE HEALTHCARE B20, User'S Reference Manual

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B40/B20 Patient Monitor
10-12
What does electrosurgical
interference look like and
how can it be minimized? Electrosurgical interference is most obvious on the displayed waveform. It is
a very spiky, erratic looking waveform caused by the electrosurgical unit’s
overwhelming interference. It can result in grossly inaccurate pulse oximeter
results.
Electrosurgical interference can be minimized by:
•
Making sure the pulse oximeter sensor is as far away from the return pad
and operating site as possible.
•
Making sure the sensor is not between the return pad and operating site.
•
Keeping the power cord and sensor cable away from the power cord of
the electrosurgical unit.
•
Plugging the electrosurgery unit into a separate set of outlets from the
monitor.
What does motion artifact
look like, what problems
can it cause, and how can
it be corrected? For modules using Nellcor OxiMax technology, the main problem motion
artifact can cause is erroneous SpO2 readings.
Motion artifact occurs with excessive motion of the sensor, the cable leading
to the sensor, or the cable/sensor junction. In other words, anything that
causes any of these things to move, like the patient moving his hands, or the
cable lying across the ventilator tubing and being moved with every cycle,
can cause motion artifact. A non-arterial, often erratic looking waveform and
a pulse rate that does not coincide with the heart rate on the ECG will result.
Motion artifact can be reduced, if not eliminated, by selecting a “quieter” site
on the patient. An ear sensor if the hands do not remain still, an adhesive
sensor on the toe, or an adhesive sensor on the little finger for an adult or on
the sole of the foot in a newborn can help greatly.
Cable movement can be reduced by applying the sensor with the cable
leading toward the patient, then taping the cable to the side of the hand or
foot. The cable and sensor can also be stabilized with a stress loop near the
sensor. Tape the stress loop to the patient (excluding children). In the case of
the butterfly sensor, the tape was designed to secure the cable to the finger.
It has been noted that letting the patient view the SpO2 waveform enables
the patient to assist in reducing motion artifact.
Why isn’t the parameter
window displayed on the
monitor after connecting
the SpO2 interface cable
and sensor? Hardware failure or an unrecognized or defective sensor.
•
Make sure the accessories are compatible with the module.
•
Make sure the sensor is attached to the interface cable and the cable is
connected to the module.
•
Change the sensor.
•
Change the cable.
If the problem persists, contact your institution’s biomedical department for
service.