Apple Watch Series 6 Blood Oxygen Monitoring Available in Most Countries Worldwide

Pulse oximetry is quite a simple and well established technology (>40 years) so there is absolutely no reason it won't be as accurate as the ones we use in hospital.

It will also be just as temperamental as the red (and infrared) LED is much more prone to interference. It's the reason why they will continue to use the green LED for plain pulse tracking - much more accurate & less susceptible to interference - particularly with exercise or any movement really.

So it will be:
- Green LED -> Exercising pulse rate*
- Red & Infrared -> Pulse Oximetry, foreground & background (+/- green LED to help lock onto the pulse rate**)
- Infrared -> background pulse rate reading when not moving*

* Just like all Apple Watches since day one.
** This is where Apple might be able to improve on existing tech

EDIT:
My money is on Apple introducing a Sleep Apnoea detection function next. The pieces of the puzzle are all there already:
- pulse oximetry
- movement detection
- noise detection

Disclosure: Anaesthesiologist

https://rk.md/2020/apple-watch-6-does-not-measure-blood-oxygen/

Yes, I made this point here in another thread yesterday. 'Blood Oxygen Levels' does not equate to 'Pulse Oximetry'.

But even my colleague there simplifies it somewhat...

You can be hypoxic even if your pulse oximetry is normal and your Hb levels are normal.

How?
If a large proportion of your Hb is in a form that can't carry oxygen (eg. from carbon monoxide poisoning). However, if you ran a sample of the same blood through a laboratory *co-oximeter* it would show that your true saturations are in fact low.

Pulse oximeters measure functional oxygen saturation, ie. what percentage of Hb that can carry oxygen (ie functional Hb), is carrying oxygen. Even hospital pulse oximeters are limited in this way.

Laboratory co-oximeters measure fractional saturation, ie. what percentage of all Hb is carrying oxygen.

In short, if your Hb is normal (ie. you're not anaemic) and there is no chance there is a lot of abnormal Hb floating around (Met-Hb, Carboxy-Hb) then pulse oximetry is a good indicator of 'oxygen levels'.

None of this really matters to the user, but they really should rename 'Blood Oxygen Levels' to 'Pulse Oximetry'. It's correctly named in the 'Health' app.

If you were significantly anaemic you'd also have an abnormally increased heart rate so perhaps the Watch might pick up on that? I just feel sorry for all my US friends that have to pay lots of money to see a General Practitioner. We pay almost nothing here in Australia (but we do pay - happily - more tax for that benefit).

It sure would be nice to find info on its stated accuracy range to see how it compares to the fingertip meter I have. The caveats about 'not for medical diagnostic purposes' are understandable, but whats the real world potential look like? I'm thinking this will be a popular use case these days.

I’m sure there will be comparisons from the usual clickbait tech tubers on day one. Looking forward to a thumbnail with some guy with a screwed up expression on his face and doing some weird pose with his hands ?

Anyway, it’s great this feature doesn’t have to go through regulatory approvals. But Apple talks about blood oxygen levels, not O2 sat. There (can be) a big difference.

Hope they release a product red iphone to match that watch. That thing looks sweet

I wish it could just show Green if you are healthy, Yellow if you are sick, and Red that you are going to die.

I wonder why it didn’t need FDA approval?

In Germany there‘s a disclaimer in every series 6 promo picture stating that blood oxygen measurement is “not for medical use, not even for self-diagnosis or consulting a doctor, and is only suitable for fitness and wellness purposes”.

This last part was also stated by the MD announcing the feature in the keynote, so I guess that’s how they get around regulation.