Philips MP2 - Smart Alarm Delay

10 Monitoring SpO2
177
CAUTION
If you measure SpO
2
on a limb that has an inflated noninvasive blood pressure cuff, a non-pulsatile
SpO
2
INOP can occur. To avoid this, the monitor can be configured to suppress corresponding SpO
2
INOPs when it detects an inflated cuff (for FAST SpO
2
technology only).
If INOPs are suppressed, there may be a delay of up to 60 seconds in indicating a critical status, such
as sudden pulse loss or hypoxia.
Alarm Delays
There is a delay between a change in the oxygen saturation at the measurement site and the
corresponding alarm indication at the monitor. This delay has two components:
• The general measurement delay time is the time between the occurrence of the saturation
change and when the new value is represented by the displayed numerical values. This
delay depends on the algorithmic processing and the averaging time configured for SpO
2
. The
longer the averaging time configured, the longer the time needed until the numerical values reflect
the change in saturation.
• The time between the displayed numerical values crossing an alarm limit and the alarm
indication on the monitor. This delay is the sum of the alarm delay time configured for SpO
2
,
plus the system alarm delay. The system alarm delay is the processing time the system needs for
any alarm to be indicated on the monitor, after the measurement has triggered the alarm. See
“Monitor Performance Specifications” on page 293 for the system alarm delay specification.
For SpO
2
high and low limit alarms, there are two different types of alarm delay time. The standard
alarm delay is set to a fixed value. The Smart Alarm Delay varies, based on an intelligent algorithm,
and can be used instead of the standard alarm delay.
The
Desat alarm always uses the standard alarm delay.
Standard Alarm Delay
The standard alarm delay time can be configured to a fixed value between 0 and 30 seconds, in
1 second steps.
Smart Alarm Delay
The Smart Alarm Delay feature tries to reduce "nuisance" alarms.
WARNING
Before using Smart Alarm Delays, make sure that you fully understand how the delay is applied and
what the consequences are.
How Does it Work?
The monitor assesses the severity of a limit violation by looking at its magnitude and duration, and can
delay the alarm, depending on the assessed severity. Examples for the delay are given in the table in the
example below.