Innokas Yhtyma Oy VC150 Manuel D’Utilisation
9-14
VC150 Vital Signs Monitor
KO00065K
Nellcor SpO
2
: Compatible Nellcor accessories
Compatible Nellcor accessories
All approved and VC150 compliant accessories are listed in the VC150 supplies
and accessories document. Use only accessories listed in that document. If you
already have an accessory that you want to use with the VC150 monitor, check
whether it is listed in that document. If it not listed, do not use it with the VC150
monitor.
and accessories document. Use only accessories listed in that document. If you
already have an accessory that you want to use with the VC150 monitor, check
whether it is listed in that document. If it not listed, do not use it with the VC150
monitor.
Nellcor SpO
2
and special features
Theoretical principles
The Nellcor SpO
2
uses pulse oximetry to measure functional oxygen saturation
in the blood. Pulse oximetry works by applying a Nellcor™ sensor to a pulsating
arteriolar vascular bed, such as a finger or toe. The sensor contains a dual light
source and a photodetector. Bone, tissue, pigmentation, and venous vessels
normally absorb a constant amount of light over time. The arteriolar bed
normally pulsates and absorbs variable amounts of light during the pulsations.
The ratio of light absorbed is translated into a measurement of functional
oxygen saturation (SpO
arteriolar vascular bed, such as a finger or toe. The sensor contains a dual light
source and a photodetector. Bone, tissue, pigmentation, and venous vessels
normally absorb a constant amount of light over time. The arteriolar bed
normally pulsates and absorbs variable amounts of light during the pulsations.
The ratio of light absorbed is translated into a measurement of functional
oxygen saturation (SpO
2
).
Ambient conditions, sensor application, and patient conditions can influence the
ability of the monitoring system to accurately measure SpO
ability of the monitoring system to accurately measure SpO
2
. Pulse oximetry is
based on two principles: oxyhemoglobin and deoxyhemoglobin differ in their
absorption of red and infrared light (measured using spectrophotometry), and
the volume of arterial blood in tissue (and hence, light absorption by that blood)
changes during the pulse (registered using plethysmography).
absorption of red and infrared light (measured using spectrophotometry), and
the volume of arterial blood in tissue (and hence, light absorption by that blood)
changes during the pulse (registered using plethysmography).
A monitoring system determines SpO
2
by passing red and infrared light into an
arteriolar bed and measuring changes in light absorption during the pulsatile
cycle. Red and infrared low-voltage light-emitting diodes (LED) in the sensor
serve as light sources; a photo diode serves as the photo detector.
cycle. Red and infrared low-voltage light-emitting diodes (LED) in the sensor
serve as light sources; a photo diode serves as the photo detector.
Since oxyhemoglobin and deoxyhemoglobin differ in light absorption, the
amount of red and infrared light absorbed by blood is related to hemoglobin
oxygen saturation.
amount of red and infrared light absorbed by blood is related to hemoglobin
oxygen saturation.
The monitoring system uses the pulsatile nature of arterial flow to identify the
oxygen saturation of arterial hemoglobin. During systole, a new pulse of arterial
blood enters the vascular bed, and blood volume and light absorption increase.
During diastole, blood volume and light absorption reach their lowest point. The
monitoring system bases its SpO
oxygen saturation of arterial hemoglobin. During systole, a new pulse of arterial
blood enters the vascular bed, and blood volume and light absorption increase.
During diastole, blood volume and light absorption reach their lowest point. The
monitoring system bases its SpO
2
measurements on the difference between
maximum and minimum absorption (measurements at systole and diastole). By
doing so, it focuses on light absorption by pulsatile arterial blood, eliminating the
effects of nonpulsatile absorbers such as tissue, bone, and venous blood.
doing so, it focuses on light absorption by pulsatile arterial blood, eliminating the
effects of nonpulsatile absorbers such as tissue, bone, and venous blood.
This signal is processed by the pulse oximeter to determine patient SpO
2
and
pulse rate data, which are displayed on the monitor user interface, system
status, and alarm information. These data are stored on the monitor and
available for subsequent export.
status, and alarm information. These data are stored on the monitor and
available for subsequent export.