Oxygen saturation (abbreviated as SO2) is one of the most important basic data in clinical medicine.
Oxygen saturation is the percentage of bound O2 out of the total blood volume as compared to the total bound O2 volume.
The oxygen saturation of normal human arterial blood is 98%, and venous blood is 75%.
It is an important indicator of the oxygen status of the body, and it is generally recognized that the normal value of oxygen saturation should not be less than 94%, and below 94% is considered to be insufficient oxygen supply.
Oximeter, that is, the instrument to determine the saturation, the main measurement indexes are pulse rate, oxygen saturation, perfusion index (PI).
Currently there are two types of oximeters: fingernail oximeters and wrist oximeters
Fingernail oximeters
Measurements are made by placing the finger inside a silicone fingerprint.
Photo credit: Kang Shang Wrist Oximeter