The role and principle of Spo2 sensor
Most of the newly developed pulse oximeters use a clip sensor probe.
When in use, the probe can be clamped on the fingertip.
In addition, two light-emitting diodes placed side by side are fixed on the upper wall of the finger clamp, and the emission wavelengths are 660nm red light and 940nm infrared light respectively.
The lower wall is a photosensitive receiving device,
which converts the red and infrared light transmitted through the finger into electrical signals.
When the oximeter is running, the time-sharing driving circuit makes the two light-emitting diodes emit light at a certain time interval and with a relatively low duty cycle.
Calculate the whole blood absorption rate a660 and a940, and then combine the experimental calibration coefficients A and B into the corresponding formula,
to calculate the value of blood oxygen saturation.
And this is a continuous and non-invasive blood oxygen measurement method,
so it will not cause any pain and side effects to people's bodies.