During the announcement of the Apple Watch Series 6, the company announced the latest element – a blood oxygen monitor – as an addition to the existing slate with health features.
“The Apple Watch is already a powerful health tool with apps that measure heart rate and heart rate,” said Sumbul Ahmad Desai, Apple’s VP of Health. “And now blood oxygen is adding a new valuable health measure for users.”
However, the features of the Apple Watch that track heart rate and heart rate have one important difference from the oxygen monitor in the blood: the heart tracking features are cleared by the Food and Drug Administration (FDA), and the oxygen monitor is not. Apple went through a long, extensive process to develop and validate an ECG function so that the watch could detect a condition called atrial fibrillation. It did not have to do the same for the pulse oximeter.
Blood oxygen monitors, or pulse oximeters, are considered by the FDA to be Class II medical devices. Generally, any company wishing to sell one in the United States must send documentation to the agency confirming that its product works as well as other versions of the same product already on the market. There is a solution, though: if the company says the product is just for fun, or for general “well-being”
That’s the route Apple went down. They do not say that their screen can diagnose any disease, only that it offers the information. Other health-focused apps and smartwatches have taken the same approach, bypassing the FDA process. “If you just provide information, they do not regulate it,” said Matt Grennan, assistant professor of health care management at Wharton School at the University of Pennsylvania. Digital health products are so ubiquitous, and so many new ones are entering the market each year, that it will be difficult for the FDA to review them all. “They need to think about how they can allocate their own resources,” says Grennan.
However, the agency takes into account when companies want to use apps to influence the medical treatment someone receives. The ECG function falls into that category. It should serve a specific medical purpose: flag abnormal heart rhythm. “It is intended to interpret and deal with a potentially life-threatening situation,” said Michael Matheny, co-director of the Center for Improving the Public’s Health through Informatics at Vanderbilt University.
As part of the FDA approval process for ECG, Apple had to provide and publish data showing that the feature can actually flag atrial fibrillation. Doctors and experts were able to examine the information, and there are dozens of published research studies that carefully examine how well the watch can actually detect dangerous heart rhythms.
Because the pulse oximeter is only a wellness product, Apple was not allowed to publish any of that information. When Matheny looked for data that showed how well the Apple Watch’s pulse oximeter worked compared to other devices on the market, he could not find much. “It applied to me,” he says. Anecdotal reports from people who tested the Apple Watch found that the pulse oximeter function is inaccurate and can be difficult to use.
The distinction between a function used for well-being and one used for medical monitoring is important – one has been cleared by experts and the other has not. But these differences are often not clear to people who buy a product like an Apple Watch, especially when marketing obscures the line – as Apple did when they directly compared the heart-monitoring features of the watch with the new pulse oximeter. “Many times patients and consumers do not understand the difference. So they start using the device and rely on the information, says Matheny.
It becomes more complicated when two applications that fall into different categories are in the same product, says Grennan. “It makes it confusing to think that one function of a device is medical in nature, and another function, which appears to be medical, is not really.”
Apple Watch will not be the last product to have some features cleared by the FDA and other features categorized as wellness tools, says Grennan. “I think we’ll see a lot more of that. Pieces of technology will have more opportunities, and some will be explored more than others. “