M3 Vital Signs Monitor Service Manual
- 23 -
display the changing light intensity in the form of changing electronic signals. The ratio between
the DC and AC of the two types of signals for light is the proportion of oxygen in the blood. Then
we can calculate correct SpO
2
value by using specified arithmetic and also calculate pulse rate
according to the SpO
2
waveform.
The SpO
2
module mainly consists of following four parts: sensor, signal processing, control unit
of LED driving sequence, singlechip.