The Apple Watch Blood Oxygen Sensor is Not Certified by Medical Experts

Apple Watch S6 Blood Oxygen Sensor Credit: Apple
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When Apple debuted its first major health sensor two years ago on the Apple Watch Series 4, it was initially restricted to users in the United States only, so we were pleasantly surprised when the new Blood Oxygen Sensor in the Apple Watch Series 6 turned out to be available in over 100 countries right out of the gate. It would seem, however, that this wider availability comes with a bit of a downside.

You see, despite both the ECG and the SPO2 sensors being of a medical nature, it turns out that there’s a reason why Apple didn’t face the same obstacles in launching the new Series 6 feature worldwide — or even within the U.S., for that matter.

The catch, it would seem, is based on how Apple has chosen to position these sensors in terms of what they can be used for. With the Apple Watch Series 4, Apple made a big deal about the new ECG app being designed to detect atrial fibrillation (Afib) signs, which required approval not only from the U.S. Food and Drug Administration (FDA) but, of course, similar regulatory approvals in other countries. In other words, it was never about Apple wanting to hold the ECG feature back, but rather about it needing certification and approval by medical experts in every country where Apple wanted to release it.

A ‘Wellness’ Feature

However, as The Verge notes, while blood oxygen monitors and pulse oximeters are normally considered “Class II medical devices” by the FDA, when it came to the Blood Oxygen Sensor in the Apple Watch Series 6, Apple was able to find a loophole that allowed it to release the feature without requiring that it go through the normal FDA approval process first.

Basically, it turns out that as long as Apple doesn’t claim that the sensor can actually diagnose or treat any medical conditions at all, it can be sold without the need for regulatory certification. It would seem that this applies not just to the FDA in the U.S., but also to government health agencies in most other countries too.

If the company says that the product is just for fun, or for general “wellness,” they don’t have to go through [an approval process]

The Verge

In other words, as long as a health sensor provides raw information without attempting to draw any conclusions from it, that’s totally okay; it’s when companies and products try to influence the medical care that someone receives that the FDA and other government health agencies feel the need to get involved.

This is the key difference between Apple’s approach to the ECG sensor, which has been positioned for the specific medical purpose of flagging abnormal health rhythms, and the SPO2 sensor, which just tells users what their blood oxygen levels are, leaving it up to them to figure out what to do about it.

An Important Distinction

As Michael Matheny, co-director of the Center for Improving the Public’s Health through Informatics at Vanderbilt University told The Verge, there’s a significant difference between a feature that’s used simply for “wellness” and one that’s used for actual medical monitoring. In fact, the SPO2 sensor on the Apple Watch somewhat concerns health experts such as Matheny.

Apple’s ECG feature had to go through a rigorous clearance process with the FDA and similar health agencies in other countries, which means that Apple had to provide data showing that the feature could reliably flag atrial fibrillation. That data had to be reviewed by multiple doctors and experts to confirm that this was, in fact, the case. Further, dozens of research studies have been done in the past two years, demonstrating that the Apple Watch detects AFib with a high degree of accuracy.

By contrast, Apple’s Blood Oxygen monitoring feature has not received any third-party scrutiny at all, and that’s left some medical experts concerned that end users may not quite understand the difference, especially when Apple’s marketing has blurred the lines by comparing the ECG and SPO2 sensors as if they’re on the same level.

In fact, there have already been anecdotal reports from people testing the Apple Watch that have suggested that the feature is “mostly useless” when it comes to accuracy, and in fact, can be harder to use than traditional pulse oximeters.

A lot of times, patients and consumers don’t really understand the difference. So they’ll start using the device and relying on the information.

Michael Matheny, co-director of the Center for Improving the Public’s Health through Informatics, Vanderbilt University

Apple, of course, does include disclaimers on its Apple Watch Series 6 product page where it states unequivocally that the Blood Oxygen app is “not intended for medical use” and is “only designed for general fitness and wellness purposes,” however this is buried in a footnote underneath the main marketing message that touts the “remarkable new sensor and app.”

As Matheny suggests, many users could be erroneously relying on the Blood Oxygen sensor in a way that it’s not designed for, and it’s a valid concern considering that many users are overreacting to heart monitoring notifications, which come from a feature that actually has received the necessary scrutiny from the medical community.

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