Generality
Pulse oximetry is a particular method, indirect and non-invasive, which allows to measure the oxygen saturation in the patient's blood; more specifically, this test allows to determine the oxygen saturation of the hemoglobin present in the arterial blood (often indicated with the abbreviation "SpO2").
In addition to data relating to blood oxygen saturation, pulse oximetry can provide information about the patient's other vital parameters, such as heart rate, plestymographic curve and perfusion index.
Pulse oximetry can be practiced anywhere, both in hospitals and on emergency vehicles (ambulances, etc.), as well as at home. In fact, being a non-invasive and completely automated method, pulse oximetry can be performed by anyone and not necessarily by specialized health personnel.
Pulse oximeter
As mentioned, to perform pulse oximetry it is necessary to use a special instrument: the pulse oximeter.
This instrument consists of a part dedicated to the detection and measurement of oxygen saturation in the blood, and of a part used for the calculation and display of the result.
The part of the instrument responsible for carrying out the measurement of SpO2 (that is, the pulse oximeter probe) can be described as a sort of pliers which, normally, is positioned astride a finger, so that the two portions that compose it one is in contact with the patient's fingertip and the other with the patient's fingernail. Alternatively, the pulse oximeter can also be positioned on the earlobe.
Generally, the probe is connected by a wire to the unit for calculating and displaying the collected data.
