A Pulse oximeter is a unit that monitors oxygenation of blood by measuring the percentage of haemoglobin saturated with O2. It is attached to the finger or ear lobe and measures the blood flow past a computerized probe in the meter. A sound or graph is usually displayed to show each pulse beat.
Two wavelengths, 650nm & 805nm are normally used as the light source that is emitted from the probe that is absorbed by the haemoglobin in the blood. The amount of saturation is indicative of the oxygenation in the blood. If blood flow is slow, there may be problems in the functioning of the pulse oximeter.
There are several situations where a pulse oximeter may not be accurate. Vasoconstriction and Venous congestion may have negative affects on the readings. Random things such as bright overhead lights and nail varnish have been known to cause false readings. Also, the presence of carbo-xyhamoglobin (methaemglobin) can cause mis-readings due to the fact that pulse oximeters can't distinguish between different types of haemoglobin.
In procedures requiring anaesthesia, pulse oximeters are put to use in monitoring oxygenation in blood as well as pulse rates. During situations of intensive care such as mechanical ventilation, pulse oximeters have been successfully used in the detection of oxygenation related problems before they manifest. Oximetry can also be used to analyze the efficiency of oxygen therapy.
A pulse oximeter is used to monitor oxygenation. However, it cannot measure the metabolism of oxygen. For oxygen metabolism, you must measure carbon dioxide levels.
Pilots flying in a non-pressurized airplanes use portable pulse oximeters to measure the amount of supplemental oxygen that is required, if required. In situations where oxygen levels may decrease, such as high altitudes and vigorous exercise, portable pulse oximeters have been very useful. People like mountain climbers and professional athletes have utilized these portable oximeters for this purpose.
Pulse oximeter applications have increased and data obtained from them has been used to create new uses. Blood volume loss is one such new realization of the capabilities of a pulse oximeter. An algorithm has been devised over eyars of experimentation which makes use of blood oxygenation and haemoglobin absorption levels to yield blood volume measurements.
Household pulse oximeter units can now be found at a variety of places and at prices that normal families can afford. Brand names like Nellcor, Checkmate, and Nonin have finger pulse oximeters for sale like portable oximeter and finger pulse oximeter.