Pulse Oximeters

A pulse oximeter is used to tell you how much oxygen is your blood.  This will inform you how much oxygen you need to take.

How does a pulse oximeter work?

Blood that has a lot of oxygen in it is brighter red than oxygen with very little oxygen in it. Blood with little oxygen will appear a much darker red, more bluish.

If you take a look at your hand, you will see bluish veins and reddish arteries. Your arteries are what send oxygenated blood (bright reddish in color) from your heart to the rest of your body. Your veins are what take your blood back (now a darker, more bluish color), once the oxygen has been dispersed.

Hemoglobin plays a very big part in your circulatory system. Hemoglobin is an oxygen transport metalloprotein in the red blood cells. It transports oxygen from the lungs to the rest of the body, including the muscles, organs, and all the cells. Oxygen binds to four sites on the hemoglobin – when all four sites are full, the hemoglobin is fully saturated.

Fully saturated hemoglobin does not absorb light in the same way that unsaturated hemoglobin absorbs light. A hemoglobin fully saturated with oxygen absorbs every color but red – therefore red is reflected and that is the color that we see. This is why well-oxygenated blood looks red.

Alright, so how do pulse oximeters fit in with all of this? Well, pulse oximeters are non-invasive. You generally place a pulse oximeter over your fingertip or earlobe. Each pulse oximeter has a light source and a detector.

As you recall from above, hemoglobin that is fully saturated with oxygen reflects light differently than hemoglobin that is not. Therefore, when the light source of the pulse oximeter is shined through your finger, the color of your blood is detected and the oxygen saturation level is discovered.

This is only a relatively condensed version of how pulse oximeters work. If you want a more specific explanation, you should ask your doctor or care provider.

There are some very effective pulse oximeters on the market today – they are very reliable and efficient. Some can be used for constant readings, while other pulse oximeters are used only for check-up readings.

It is important to note, though, that regardless of the reading that your pulse oximeter tells you, you should never change the flow of oxygen coming from your oxygen unit unless your caregiver and/or doctor approves.