During a pulse oximetry reading, a small clamp-like device is placed on a finger, earlobe, or toe. Small beams of light pass through the blood in the finger, measuring the amount of oxygen. It does this by measuring changes of light absorption in oxygenated or deoxygenated blood. This is a painless process.
The pulse oximeter will thus be able to tell you your oxygen saturation levels along with your heart rate.
Pulse oximeter accuracy
Universal access to pulse oximeter around the world is often limited by cost and has important consequences for public health. Low-cost pulse oximeters are increasingly available with limited oversight from regulatory agencies. The accuracy of these devices has often not been validated, raising questions about performance.
Many inexpensive pulse oximeters sold to consumers show very inaccurate readings. Unexpectedly, the accuracy of some inexpensive pulse oximeters tested here performed similarly to the more expensive, ISO-approved units when measuring hypoxia in healthy subjects.
However, further development of low-cost and accurate oximeters for use in clinical practice is feasible.
All pulse oximeters marketed for medical use in the United States are required by the Food and Drug Administration (FDA) to have been tested and certified to be accurate to root mean square error (ARMS) of <3% at Sao2 between 70% and 100%.
The great majority of calibration and confirmation tests are done on healthy volunteer subjects.
Pulse oximeter for home use
The oxygen concentration is measured with a device called a pulse oximeter. Although not many people know it, it is a medical device originally developed in Japan that later spread to the rest of the world.
The pulse oximeter makes it possible to measure the saturated oxygen concentration (SpO2) —oxygen bound to hemoglobin— immediately, projecting two types of light with different wavelengths on the fingertip and analyzing the light that is filtered without being absorbed.
The more oxygen is bound to the hemoglobin, the lighter the red hue of the light. The oxygen concentration in blood is calculated by digitizing the intensity of the color.
Fingertip pulse oximeter
Current pulse oximeter models have been greatly simplified, a small clamp-like sensor device is attached to the fingertip to measure heart rate and oxygen concentration, and displays them on a small, built-in screen.
The maximum concentration is 100% and the normal value is between 99% and 96%. A concentration below 90% is considered too low and is treated immediately by supplying oxygen to the patient.
- The vital signs that are usually measured in the hospital are four:
- blood pressure
- heart rate
- respiratory rate and
- But the concentration of oxygen in the blood is such an important value for life that the pulse oximeter is said to measure the fifth.
Pulse Oximeters: Answering Your Frequently Asked Questions
As per the studies, your right hand’s middle finger shows the best results. Make sure to take off any nail polish and avoid using cold fingers as the readings may not show correctly.
Blood gas measurements provide critical information regarding oxygenation, ventilation, and acid-base status.
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- What is a normal oxygen saturation level?
- Are any oximeters made in the USA?
- Pulse oximeters FDA approved and more…