How A Pulse Oximeter Works

#TheDevDoctor #PulseOximeter #SatsProbe #HowStuffWorks

Hi Guys, welcome back to the channel. For those of you who are new; Hi my names Matt and I'm a junior doctor working in the UK's National Health Service and today I want to talk to you about how a pulse oximeter, or oxygen saturation probe, works.

Pulse oximetry has been used in medicine for some time now, but since the coronavirus pandemic, the public has been starting to use them more frequently to measure their own oxygen saturation. A pulse oximeter effectively tells us how much oxygen is in our blood at any one time.

Pulse oximeters exploit the difference in absorption profiles of red and near-infrared light to detect the level of oxygenation within the blood. Pulse oximeters emit two wavelengths of light, red light at 660 nm and near-IR at 940 nm from a pair of small light-emitting diodes located in one arm of the finger probe. The light that is transmitted through the finger is then detected by a photodiode on the opposite arm of the probe. From this, the probe can calculate the relative amount of red and IR light absorbed and this is used to ultimately determine the proportion of Hb bound to oxygen.

Thanks for watching the video guys. If you have any questions please remember to leave a comment below this video and I'll try to respond as soon as possible.

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[Peace]

Super! One of the best videos out there on the topic.

[mathewmartin]

Great video with awesome graphics to help deliver a crisp message. There are some assumptions that I believe are made starting around the 2 min mark. The sensor is reading a frequency of light change. That change is an electromagnetic change, not an oxygen hand over (although that is assumed to be happening), resulting from a charge change. How can you prove that oxygen is being perfused or moves across a membrane when the tool does not measure oxygen but charge?

[annaberg]

What should it look like if it's good?? I don't get it

[raylee]

Masimo sued Apple for patent violation and won.

[michaelwain]

will deeper breathing increase oxy blood saturation

[TheDreamcatcher]

I just wanted to know how to simply & quickly interpret the readings on the oximeter.

[kellyriddell]

This was a really interesting and informative explanation - thank you! You made a good point about health anxiety potentially stemming from using pulse oximetry out of a medical context (like through wearable tech), but I wonder if education might be the answer there. When you know how tools work properly and what they actually tell you, they empower you. At least for me, having one while sick with COVID and understanding how to use it and interpret the reading made me feel more confident that I was safe, even if I felt like I was on death's door. My case ended up being mild and I really didn't probably even need to use the oximeter, but knowledge is power.

[luckydog-]

Can't get better than that! Thank you!

[zennaparamore]

I still don't know which number is which and what a normal reading should be.

[stephenuk]

Good explanation. I got lost on some of the technical stuff but found it very useful anyway.

[haramedical]

I think this is the best explanation of pulsoximetry! thank you sir, really enjoyed watching you, and of course never thought that a simple finger pulsoximetre has such ammount of science principles, its just mind blowing!😇

[ottotater]

When I ask google to tell me how things work, it usually gives me some limited quickstart guide. It's very nice to actually see the appropriate answer of how something works. Quality wise this is one of the best videos I've seen in a while.

[amandathorpe]

I do have bronchitasis and scarred lungs and when I am walking I need oxygen for Pulmonary Fibrosis. I do have cold fingers and feet because of hypothyroidism. I am not feeling well and now I'm wondering if because of my cold fingers I am getting the wrong numbers tonight between 90 and 91 is that alright or should I get my oxygen. I'm also extremely tired and I couldn't finish my dinner?

[helenwest]

Thank you - I had to listen two times but got the information that I needed.
Before going on oxygen my numbers were low (80 and less) this changed after I was put on oxygen. Too, you might want to mention the low number being a result of numbness ( in my case from radiation) and how cold affects the reading. Again thank you
Helen Bowes, Philadelphia PA

[carlenegraydon]

Great information but one thing I missed if your sp02 is 97 and your ❤ rate is 66 is that good in a resting state

[musculuslevatorclunei]

Thank you for this great animation and explanation. It is gold video.

[rajamoeez]

I love all of these, you are very creative!

[gmot]

Great comprehensive explanation. Convinced me I should leave this to the hospitals. I don't need this after all. Thanks

[bikeman]

Well done doc. Thorough knowledge of the science, application and the engineering of the device. If you were working as an engineer in the tech industry and presented at a product development meeting, you would get immediate attention and respect.

[suginami]

Just wanted to know quickly and simply what the two numbers mean.