Blood oxygen monitoring returning to Apple Watch in the US

thm | 439 points

Apple was in a patent dispute over this feature with Massimo. Their workaround is to calculate blood oxygen on the iPhone, using the sensors from Apple Watch.

The Apple Watch hardware is otherwise the same. The back of the watch shines light of a specific wavelength into your skin and measures the reflected light. Heart rate sensing uses green (525 nm) and infrared (850–940 nm) light; blood oxygen sensing added a red light at 660 nm in 2020.

The iPhone will now calculate the ratio of absorbed red to infrared light, then apply calibration constants from experimental data to estimate blood oxygen saturation.

More detailed writeup on how the technology works is here: https://www.empirical.health/metrics/oxygen/

brandonb | 2 days ago

In my experience, the Apple Watch blood oxygen monitoring was horribly inaccurate. It would report wildly variable results, often telling me that I had a blood oxygen level of 80% (which, if true, would indicate that I should be getting myself to an emergency room ASAP).

Regular pulse oxygen meters are cheap and reliable.

neild | 2 days ago

Just offloading the analysis to the phone is extremely funny. It also seems like a pretty obvious solution, so I wonder if it was delayed by legal analysis and they only just decided it was likely to hold up in court.

dmart | 2 days ago

I never really understood why protecting Massimo in this situation was more important than allowing customers to access a feature in their watch. I get patent law is important, but they seemed more interested in rent-seeking from Apple than actually providing a desirable product that people could benefit from.

kylehotchkiss | 2 days ago

I have it on my garmin and it seems pretty useless. My oxygen level while I sleep has more to do with how tightly I'm wearing it that night than anything else. It also drain the battery fast so I just disabled it.

I have a real finger-based one bought during COVID that I trust more.

comrade1234 | 2 days ago

Hopefully blood glucose monitoring will come soon as well

mandeepj | 2 days ago

Let's be clear: the return of this function requires an iPhone; the original version did not.

bookofjoe | 2 days ago

What's the US Customs ruling in question? > This update was enabled by a recent U.S. Customs ruling.

sargun | 2 days ago

Did the Watch Series 9+ incorporate a new sensor or different algorithm? I have an older model that has always had blood oxygen (and it was never disabled, as it was for the 9+).

alistairSH | 2 days ago

A family member has one of these watches. Instant hypochondriac. Probably already was but the watch really brought it out. They're constantly monitoring their vitals rather than getting on with life and have already made more than one ER visit on account of a reading that worried them.

jacquesm | 2 days ago
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| 2 days ago

BTW the O2 monitoring is inaccurate and unreliable compared to a proper pulse oximeter.

temporallobe | 2 days ago

What's different in Samsung's approach, that kept them out of this dispute? Why didn't Apple follow Samsung's solution, if not patent restricted?

netfortius | a day ago

Been holding off buying a watch till glucose monitoring hits.

Much like fusion that is continuously imminent though

Havoc | 2 days ago

Interesting they offload the processing to iphone. The Soc on apple watch is quite capable. Maybe they don't want to drain your AW battery and prefer draining your iphone's instead.

mrheosuper | 2 days ago

I have the first Ultra and just looked back at the data and they were never interrupted. It isn't included in the release either. Wonder what is different about it. Did apple arrive at a separate agreement for that device?

cogogo | 2 days ago

I wish they could monitor blood insulin.

bilsbie | 2 days ago

Can you do anything interesting with knowing blood oxygen?

bilsbie | 2 days ago

To be honest, I didn’t like these metrics. They’re very different from what I get on an oximeter. The first time I saw them, I thought I was short of breath, but it was just the metric being used.

delduca | 2 days ago

You can buy a fingertip pulse oximeter for like $10. I understand the benefits of having all of these biometric readers directly on your personal device, but the perceived stress over getting this back into the watch seems... I don't know, not wise? In poor taste? Something, but I can't articulate it well.

I mean, we don't have IR blasters on any of our personal devices anymore, and arguably it would be nice to be able to control my TV with my phone like I could with my Palm Pilot forever ago, but that's not in vogue anymore.

andrewmcwatters | 2 days ago

Why were they removed in the first place?

southernplaces7 | a day ago

Massimo invented this technology (yay Massimo!) in the 90s yet their Japanese patents [1] weren't considered prior art (WTF?) because of technical legal reasons.

[1] https://patents.google.com/patent/JP2002542493A5/en%EF%BF%BC

So I suppose if Massimo is going to use a technical legality to extend then Apple can use a technical legality to avoid.

CalChris | 2 days ago

Which will be absolutely useless for anyone serious and even plebs like me since who runs with a 250-500g phone strapped into spandex?

I use a watch and wireless headphones. The iphone stays at home.

hinkley | 2 days ago

blood oxygen from the wrist is absolutely garbage-in

ck2 | 2 days ago

I live in a rural area. My old fashioned doctor said to test oxygen levels, all you need to do is pinch your index finger nail down until it goes white. Then when you let go, if it goes back to pink right away, you're good. If it takes more than a few seconds, you're not good.

DwnVoteHoneyPot | 2 days ago