Nellcor OXIMAX N-560, Operator'S Manual

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Technical Information
88
The method of calculation is as follows:
The number of percentage points that the %SpO
2
falls outside the alarm
limit is multiplied by the number of seconds that the %SpO
2
level remains
outside that limit. This can be stated as an equation:
Points x Seconds = SatSeconds
Where:
Points = SpO
2
percentage points outside of the limit
Seconds = number of seconds that SpO
2
remains at that point
outside of the limit
The alarm response time, assuming a SatSeconds limit set at 50 and a
lower alarm limit set at 90, is described and illustrated below.
In this example, the %SpO
2
level drops to 88 (2 points) and remains there
for a period of 2 seconds (2 points x 2 seconds = 4). The %SpO
2
then
drops to 86 for 3 seconds and then to 84 for 6 seconds. The resulting
SatSeconds are:
After approximately 10.9 seconds, the SatSeconds alarm will sound,
because 50 SatSeconds will have been exceeded. See arrow (
↑
) in
Figure 6.
%SpO
2
Seconds SatSeconds
2 x 2 = 4
4 x 3 = 12
6 x 6 = 36
Total Sat Seconds = 52