Cardinal Health Alaris 8000 Series, Инструкция по применению

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Principle of Operation (Continued)
General Information
4-33 Alaris
®
System Directions for Use
SpO
2
Modules Section
8220 Series
(8220)
The operation of the
S
p
O
2
Module (
8220
Series) is based on
the principles of pulse oximetry. Oxyhemoglobin and
deoxyhemoglobin differ in their absorption of red and infrared
light (spectrophotometry). The volume of arterial blood in
tissue and the light absorbed by the blood changes during the
pulse (plethysmography).
Because oxyhemoglobin and deoxyhemoglobin differ in light
absorption, the amount of red and infrared light absorbed by
blood is related to hemoglobin oxygen saturation.
The
S
p
O
2
Module uses the Masimo
®
Signal Extraction
Technology
®
(
SET ®
) to decompose the red and infrared
pulsatile absorbance signal into an arterial signal plus a noise
component. Its value is used to find the
S
p
O
2
saturation in an
empirically derived equation in the Masimo
® SET ®
software.
The values in the look-up table are based on human blood
studies against a laboratory co-oximeter on healthy adult
volunteers in induced hypoxia states during motion and
nonmotion conditions.