Principles Of Operation; Oximetry Overview - Nellcor OxiMax N-65 Operator's Manual

P r i n c i p l e s o f O p e r a t i o n

Oximetry Overview

The O
XI
functional oxygen saturation in the blood. Pulse oximetry
works by applying an O
arteriolar vascular bed, such as a finger or toe. The
O M
XI AX
detector.
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
SpO is dependent upon light from the O
2
excessive ambient light can interfere with this
measurement.
For additional information about ambient conditions,
O M
XI AX
OXIMAX N-65 Performance Considerations on page 87.
Pulse oximetry is based on two principles:
O Max N-65 Operator's Manual
XI
M N-65 uses pulse oximetry to measure
AX
M sensor to a pulsating
XI AX
sensor contains a dual light source and a photo
). Because a measurement of
2
sensor application, and patient conditions, see
• oxyhemoglobin and deoxyhemoglobin differ
in their absorption of red and infrared light
(spectrophotometry)
• the volume of arterial blood in tissue (and
hence, light absorption by that blood)
changes during the pulse (plethysmography)
M sensor,
XI AX
113