Spo 2 Processor Circuit Boards; Spo2 Processor Circuit Boards; Spo 2 General Theory Of Operation; Nellcor Nell-3 Spo Circuit Board Theory Of Operation - Datascope Accutorr Plus Service Manual

Theory of Operation
1.3 SpO
The Accutorr Plus can be equipped with one of two optional technologies:
• Nellcor ® SpO
• Masimo ® SpO
Each technology uses proprietary sensors and interface cables. There are no "adapters"
possible or available.
1.3.1 SpO
Regardless of manufacturer, SpO
red and an infrared light source. A sensor from the instrument contains two sets of LEDs
to illuminate a portion of the body (for example, a fingertip) and a single photo sensor
detects the light returned. The LEDs are alternately pulsed, red and infrared. Since
hemoglobin is the carrier of oxygen in the blood and the relative attenuation of the light
sources is proportional to the amount of oxygen carried by the hemoglobin, a relative level
of saturated hemoglobin can be determined. Since we are measuring the ratio of red and
infrared return from the circulatory system, the detection method is substantially
independent of skin color or total skin attenuation. Since the blood flow has a pulsatile
characteristic, a pulse rate can also be computed from this information.
NOTE:
NOTE:
1.3.2 Nellcor
The Nell-3 is a complete SpO
Nellcor ® Puritan Bennett. Patient data is processed for serial transmission to the host
system.
Accutorr Plus Service Manual
Processor Circuit Boards
2
system
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system
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General Theory Of Operation
2
There is no calibration possible for the
determination of the SpO
derived. As mentioned above, we are measuring a
ratio of intensity of two light sources to
determine the % of saturated hemoglobin. The
determination is based on proprietary software
interpretation of the reflected light ratios, and it
is validated against strict clinical trials where
fresh arterial blood is examined with a clinical
blood gas analyzer. Once the software is
finalized, the SpO
there are no possible adjustments.
The wavelengths of the light emitted are
nominally 660nm and 890nm with the energy not
exceeding 15mV.
®
Nell-3 SpO Circuit Board Theory of Operation
2
detection and determination circuit, proprietary of
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0070-10-0691
determination is based on the relative attenuation of a
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% or of the pulse rate
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monitor accuracy is fixed and
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SpO Processor Circuit Boards
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