Oximeter
Definition
Oximeter is a photoelectric device that measures oxygen saturation of the blood by recording the amount of light transmitted or reflected by deoxygenated versus oxygenated hemoglobin.
Description
The oximeter consists of a light-emitting diode (LED), a photodetector probe containing a permanent or disposable sensor, alarms for pulse rate and oxygen levels, a display screen, and cables. The device works by emitting beams of red and infrared light that are passed through a pulsating arteriolar bed. Sensors detect the amount of light absorbed by oxyhemoglobin and deoxyhemoglobin in the red blood cells. The ratio of red to infrared light measured by the photodetector indicates the amount of oxygen present in the blood. The sensor is attached to the body over the arteriolar area in the ear, the fingertip, the big toe, or across the bridge of the nose. Clip sensors can be used on fingers or the earlobe.
The pulse oximeter is widely used in most hospitals and in research laboratories that study pulmonary function. Oximeters are used in hospital settings such as intensive care units, pulmonary units, and in health care centers. Portable hand-held devices are available, and are used to spot check patients and for in-home use under the supervision of a physician.
There are several different ways of measuring a person’s oxygen saturation, or the amount of oxygen carried through the blood. Often in hospitals or other clinical settings, a pulse oximeter is used. Just as medical tools such as the blood pressure cuff have made its way for home use, so has the pulse oximeter. These were designed so that people could use these at home, in a small, and easy to use configuration.
Advantages of Pulse Oximeter
The safest, quickest and least invasive means by which to determine a patient’s oxygen saturation is with a pulse oximeter.
Speed
Pulse oximetry measures a patient’s arterial saturation of oxygen (SaO2) in seconds; measurements obtained from arterial blood gases (ABG) can take several minutes to acquire and are usually drawn by a respiratory therapist, transported to the blood gas lab, measured and finally reported back to the doctor. The information from an ABG analysis provides for more information than just the oxygen level and is essential in emergencies, but oximetry is equally important to ensure the patient does not suffer the effects of hypoxia unnecessarily.
Accurate and Easy to Use
While not as precise as an ABG measurement, pulse oximeters are accurate with most patients, especially in emergency situations where seconds matter; however, it should not be used indiscriminately for some chronic conditions, such as chronic obstructive pulmonary disease (COPD), in which a patient may have chronically low oxygen levels and raising them too high can be dangerous. Little to no training is needed to perform pulse oximetry. Most oximeters have only one button and as long as the probe is placed properly, virtually anyone can use it. In their infancy, oximeters were the size of old cassette recorders and just as cumbersome. The newest generation of oximeters is streamlined, rugged and even easier to use. Furthermore, they are now available for home use.
Non-Invasive and Reliable
ABG measurements, though exact, require blood drawn from an artery, which can lead to complications ranging from hematoma to laceration of the artery. Pulse oximetry is performed on a fingertip and measures through the nail bed. As long as the oximeter is used properly and is calibrated regularly, it is easy to use and usually reliable. Good peripheral circulation in the patient’s extremities is critical to obtaining accurate readings and most oximeters on the market incorporate a perfusion gauge, usually in LED bar lights, that shows the strength of the patient’s peripheral circulation. When a strong pulse is not present in the hands or feet, readings can be made with a special adhesive probe placed on the patient’s earlobe or even the bridge of the nose.
Processing your request, Please wait....
