GE CARESCAPE, User Manual

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Pulse oximetry
Nellcor OxiMax data averaging and updating
The Nellcor OxiMax algorithm automatically extends the amount of data required for
measuring SpO
2
and pulse rate depending on the measurement conditions. During
normal measurement conditions in the normal response mode, the averaging time
is 6 to 7 seconds.
During difficult measurement conditions, which can be caused by low perfusion,
motion, ambient light, electrocautery, other interference, or a combination of these
factors, the OxiMax algorithm automatically extends the dynamic averaging time
required beyond 7 seconds.
If the resulting dynamic averaging time exceeds 20 seconds, the pulse search
condition will be set, while SpO
2
and pulse rate values continue to be updated every
second.
As the measurement conditions become even more difficult, the amount of data
required continues to expand. If dynamic averaging time reaches 40 seconds, the
pulse timeout condition will be set and the module will report a zero saturation
indicating a loss-of-pulse condition.
Selecting the SpO
2
response time
NOTE
PDM Nellcor only.
You can select the response (averaging) time. Fast (default) is the recommended
setting.
1. Select the SpO
2
parameter window.
2. Select the SpO2(2) or SpO2(2) tab.
3. Select the radio button for the response time: Normal or Fast .
Nellcor OxiMax Saturation Seconds alarm management
NOTE
PDM and TRAM with primary SpO
2
measurement and the
Nellcor option only.
The Saturation Seconds feature has a “safety net” designed for patients whose
saturation is frequently outside the limits but does not remain outside the limits long
enough for the Saturation Seconds limit to be reached. When three or more limit
violations occur within 60 seconds, an alarm sounds even if the Saturation Seconds
limit has not been reached.
Nellcor OxiMax technology uses the Saturation Seconds to decrease the likelihood of
false SpO
2
saturation alarms caused by motion artifact. It does not apply to pulse rate.
With traditional pulse oximetry alarm management, upper and lower alarm limits are
set. During monitoring, as soon as a limit is violated, an alarm is generated. With
Saturation Seconds alarm management, upper and lower alarm limits are set in the
same way as traditional alarm management. If the alarm priority is
Escalating , the
alarm priority limit automatically changes to Medium .
A Saturation Seconds limit is also set. This allows monitoring of SpO
2
saturation
outside the set limits for a period of time (count value) before an alarm sounds. The
method of calculation is as follows: The number of percentage points that the SpO
2
saturation falls outside the alarm limit is multiplied by the number of seconds that it
remains outside the limit. This can be stated as the equation “points x seconds =
2062971-001 CARESCAPE Modular Monitors 211