Pulse oximetry

Pulse oximetry is like a special watch that tells us how well our body is getting oxygen. You know how we need oxygen to breathe and stay alive, right? Well, this little watch helps us see how much oxygen our body is getting.

The watch works like a tiny flashlight that goes on your finger or earlobe. The flashlight shines a special red light through your finger or earlobe, and a detector on the other side of your finger or earlobe can see how much of that light is coming through.

The really clever part is that the watch can see how much of the light that gets through is the oxygen in our blood, and how much is not oxygen. It's kind of like seeing how much cheese there is on a slice of pizza, and how much is sauce and crust.

When the watch calculates how much of the light is oxygen, it can tell us how much oxygen is in our blood. This is important because if we don't have enough oxygen in our blood, our body can't work properly.

So, sometimes doctors or nurses put this watch on our finger or earlobe to check how much oxygen our body is getting. It doesn't hurt at all, and we can play or do other things while wearing it. It's like wearing a little sleepy time bracelet while taking a nap, but instead of measuring how much you sleep, it measures how much oxygen your body is getting.