How do you read a Pulse Oximeter?

How do you read a pulse oximeter?

The pulse oximeter will thus be able to tell you your oxygen saturation levels along with your heart rate.

• 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 in light absorption in oxygenated or deoxygenated blood.
• This is a painless process.

What are the 2 readings on a pulse oximeter?

Whether you are ill, experiencing a medical emergency, or the victim of an accident, the first thing a nurse will do is slip what looks like a small clip on one of your fingers to gather two pieces of information:

• Measure blood oxygen saturation (SpO2) and
• Pulse rate with a home pulse oximeter.

This non-invasive device clips onto the index finger to measure changes in the light wave spectrum through the finger during pulsation of blood, which generates a measure of blood oxygenation and pulse rate sent to the pulse oximeter.

How to use pulse oximeter?

Your pulse oximeter will give you a numerical reading — a percentage that indicates the level of oxygen saturation in your blood. If you’ve been to a doctor in the past years, you’ve experienced pulse oximetry.

The device works better with warmer hands than cold hands. And because oxygen levels can fluctuate, consider taking measurements a few times a day.

Also try it in different positions, such as while lying flat on your back or while walking. Keep notes to share with your doctor if needed.

Pulse oximeter – how it works?

Before you can really understand how a pulse oximeter works, you have to understand what it is measuring.

Oxygen is vital to life

Every organ, muscle, nerve, and tissue in the body needs oxygen to function the way it should. However, for oxygen to be used by the body, it must travel from the lungs to the intended destination via hemoglobin, or red blood cells.

If half of your hemoglobin cells are carrying oxygen, your oxygen saturation is 50 percent. If all of them are carrying oxygen, your oxygen saturation is 100 percent.

Blood is not stagnant in your veins

Instead, with every heartbeat, your blood travels too and from your extremities where your oxygen levels are often tested.

However, rather than trying to pulse red and infrared light through your finger and hopefully capture a reading timed perfectly with your heart rate, the pulse oximeter emits a constant stream of light.

It must, therefore, calculate the “changing absorbance” in your finger – the light absorbance that happens with every heartbeat. That is why a pulse oximeter produces two readings – your pulse rate and your oxygen absorption.

More on this story

Pulse Oximeters: Answering Your Frequently Asked Questions