Pulse Oximeter: Uses, Mechanism, Price, Tips & Tricks

Pulse Oximeter is one of the small medical tools which can be a life-saving device for you. I hope you are healthy in this corona time in the world, and I pray everyone stays healthy. In the current crisis, the pulse-oximeter has become a handy object, which at the same time indicates when the corona-infected patient has to go to the hospital. I will try to explain in straightforward language so that medical (those who do not usually work in critical care) / non-medical, i.e., everyone can understand and use the pulse-oximeter well. I will explain everything based on books and actual use.

Pulse Oximeter: Uses, Mechanism, Price, Tips & Tricks


1. The primary working type of oximeter

2. How to use it?

3. What are the reasons for giving false readings?

4. How to keep the oximeter clean?

5. What to do when oxygen saturation decreases?

Below is a description in as few words as possible


There are two types of light rays – one is red light (which we all see with the naked eye), and the other is infrared light (which we can’t see by the naked eye). And there is a light-sensitive plate. Everyone may think that this red light helps to measure/see the saturation, but in fact, it works oppositely. Oxygen in the blood is associated with a substance called hemoglobin. This combined oxy-hemoglobin absorbs infrared light, and red light absorbed by the oxygen-deficient / deficient part. After absorbing infrared light, it again prevents the absorption of red light. These 2 give the oximeter saturation readings depending on the level of absorption of light. There is only one reason for saying this explanation – if the intake of light changes in any way, the saturation will also change.


1. Many people hold the oximeter and press it forcefully. It is not the right way.

2. If for some reason, the spring is loose, you can hold it very lightly, but no extra pressure should be applied.

3. In the case of younger children, two fingers should be given together (only two small fingers inside the probe of the oximeter).

4. You can also apply it in the fingers and toes of young children.

5. You can place some oximeters on the ear lobes.


1. Nail polish/any color on the nails.

2. The color/part of the food sticking to the fingertips (yellow/yellowish)

3. Excessive sweating of hands

4. Holding water / any other wet material in hand

5. Moving hands and fingers inside the oximeter.

6. Brighter lights (such as sunlight). So, you should not use it outdoor.

7. If the accumulation of dirt over the light source of the oximeter and the on the photosensitive plate.


1. Do not press hard or apply excessive pressure when holding the probe in hand.

2. Wash hands before watching saturation.

3. Thoroughly clean the inside with alcohol pad/tissue.

4. You should not throw it forcefully.

5. Keep away from electromagnetic objects (fridge, oven).


An alarm will be triggered when it gets a saturation below 92%. In those cases, you should provide Oxygen as soon as possible and hospitalization the patient.

Some oximeter shows too much saturation. One of the reasons for this is the error in the machine. Another reason is smoking. Many smokers proudly say that they have good saturation even after smoking. Smoking shows incorrect readings due to the high carbon-monoxide content in their body, which can lead to harm in any more severe illness.

Dr. John Chowdhury initially writes the contents of this post on a Facebook group named Box of Happiness. The group sells the original Pulse Oximeter. You will know about the price by joining the group.

Thanks for reading this post.

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