Pulse oximetry is a non-invasive technique of monitoring the level of saturation of oxygen gas in the blood of a patient. This monitoring is done using a recording pulse oximeter. The device monitors the way oxygen saturation changes in the body and alerts the doctor or the patient when it falls under dangerously low levels. This allows for fast intervention hence preventing possible loss of life or commas.

Spectrophotometry is the main principle that the working of these gadgets bases on. This principle is dependent on the mode of absorption of red and infrared radiation by deoxygenated and oxygenated blood cells. These rates of absorption are recorded by the sensor and passed to the main machine for processing. The main machine gives fresh values at intervals of 0.5 or 1 seconds after processing. This high rate ensures high accuracy.

The gadget comprises of two light emitting diodes that emit infrared and red radiations. When in use, the diodes must be placed directly opposite to their respective detectors. The detectors and the diodes should then be separated by 5-10 mm of tissue. This is why an oximeter must be placed on an organ with thin tissues like an earlobe or fingertip. Sensors of the device are made into clips or wraps. Recent studies show that oxygen saturation inside the body cannot be measured effectively through earlobes.

These devices find use in any medical setting where blood oxygen saturation needs to be monitored at all times. Examples of such settings are operation rooms, recovery and treatment wards, emergency units, and intensive care. Accuracy of the readings is ensured by the patient staying calm and avoiding big moves. Devices that are able to record values are better because a history of values recorded within a given period can be maintained.

Oximeters have several uses besides measuring oxygen saturation. First, oximetry can serve as a replacement for blood gas analysis except in cases where acid-base state or PaCO2 is necessary. This method is also cheaper, easier to perform, and less painful compared to many others. It also has a higher level of accuracy especially in cases where the patient is conscious. Recorded values can be used to determine variations and to set standards in patients.

Oximeters also prevent wastage of oxygen supplied to patients by keeping usage only to required levels. Intrapartum fetal monitoring and neonatal care are the other areas of usage. Use in neonatal care and intrapartum fetal monitoring are not developed and standardized fully but soon they will. First aid in modern ambulances is provided by these devices. GP kits are progressively getting equipped with oximeters.

In primary care, oximetry finds use in diagnosing and managing exacerbation of chronic obstructive pulmonary disease in a location. It also helps in grading the level of seriousness of an asthma attack. An asthma attack is considered life-threatening is the level of saturation falls at or below 92 percent. Severity of bronchiolitis in children is also assessed and medically cared for through this method.

The recording function in recording oximeters makes them to cost a little higher than other models. Prices vary according to the degree of complexity. Stores that sell medical equipment are among the places one can buy these devices from.