The pulse oximeter technology, developed by Takuo Aoyagi in the 1970s, emits two wavelengths of light (red and infrared) through the fingertips to measure oxygen levels and heart rate. Hemoglobin absorbs two different amounts of light, depending on its saturation with oxygen, and a sensor on the opposite side of the finger from the diodes reads the amount of light absorbed.
Most commercially available oximeter devices like zacurate pulse oximeter measure from the fingertips, although some probes attach to the ears or wrap around the feet. They’re about the same size as two stacked 9-volt batteries, and the spring-loaded hinges similar to that of a clothespin. When you clip the oximeter on to your finger to turn it on, it takes a few seconds for the reading to appear. Unlike blood tests used to measure arterial oxygen saturation (SaO2), it is completely non-invasive and allows the patient to be measured without bothering.
How does a pulse oximeter work?
A pulse oximeter is a small device that clips on a part of your body, such as your finger, toe, earlobe, or forehead. Often used in a critical care setting such as emergency rooms and hospitals. Some doctors use it in the office as part of their routine checkup.
When a pulse oximeter is attached to a part of the body, a small beam of light passes through the blood and measures the amount of oxygen. This is done by measuring the changes in light absorption of oxygenated or deoxygenated blood. A pulse oximeter displays the oxygen saturation along with the heart rate.
Difficulty breathing during sleep known as respiratory arrest or SBE, which can occur as obstructive sleep apnea, can cause repeated decreases in blood oxygen levels. Long-term hypoxia during sleep is known to cause a variety of health complications, including depression, heart disease, high blood pressure, and diabetes.
How to use a pulse oximeter?
The pulse oximeter can be used in both clinical and outpatient settings. In some cases, doctors may recommend a home use pulse oximeter.
The pulse oximetry process is as follows:
- A clip-on device is usually placed on your finger, earlobe, or toe. You may feel a little pressure, but no pain or pinching. In some cases, a small probe may be placed on your finger or forehead. If you have nail polish on your fingers, you may be asked to remove it.
- Keep the probe on for as long as you need to check your heart rate and oxygen saturation. When monitoring physical activity capabilities, this will be during the extent of the exercise and during the recovery period. During surgery, the probe is placed beforehand and removed when you are awake and no longer under supervised. In some cases, it is only used to make a single reading very quickly.
- Remove the clip or probe when the test is complete.