Mindray DPM 4 Service Manual

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2.2.4 SpO
2
Module
2.2.4.1 General
This module provides the function of measuring the Pulse Oxygen Saturation (SPO
2
).
2.2.4.2 Principle diagram
Figure2-7 Working principle of the SpO2 module
2.2.4.3 Principle
The SpO2 measurement principle
1. Collecting the light signal of the red light and infrared transmitting through the finger or toe
which is pulsing;
2. Processing the collected signal to get the measured result.
The drive circuit of the LED and the gain of the amplifying circuit should be controlled according
to the different perfusions and transmittances of the tested object.
Led Drive Circuit
This circuit supplies the LED with the drive current, which can be regulated.
SPO2 Signal Process Network
The pre-amplifying circuit converts the photoelectric signal to the voltage signal and conducts the
primary amplification.
The gain adjusting and amplifying circuit conducts the secondary signal amplification and adjusts
the gain.

Mindray DPM 4 Specifications

General

Brand	Mindray
Model	DPM 4
Category	Medical Equipment
Language	English