Fitbit recently filed a patent application (pdf) for a force-sensitive display that would enable blood pressure measurements on wearables. But even as patents did guaranteeing success — which they don’t — the past few months have made it hard to have any confidence in the future of Fitbit smartwatches.
First of all, don’t read too hard in patent applications. While it can give you an idea of what a company is working on, it is a legal tool for companies to effectively voice a particular innovation. In the claims section of this request (through Portable), Fitbit outlines a force-sensitive screen paired with a photoplethysmography (PPG) sensor that, when pressed, can estimate your blood pressure.
The nice thing about this concept is that it essentially uses the traditional blood pressure cuff. They work by cutting off blood flow in an artery. That pressure is then slowly relieved, helping doctors figure out when blood flow will start back up (systolic reading) and when your heart will relax again (diastolic reading). High numbers can be a sign that your heart is working too hard to pump blood around your body.
It’s not too surprising that blood pressure would be on Fitbit’s radar. It’s far from the first wearable to include this feature. Samsung has had it on his Galaxy Watches for some time, although it uses a different mechanism that requires periodic calibration than a traditional cuff and is not available in the US for regulatory reasons. There’s also the Omron Heart Guide – an FDA-approved smartwatch where the strap doubles as an inflatable cuff.
However, there is new momentum for cuffless, non-invasive blood pressure wearables that use PPG sensors. Valencell, which develops biometric sensor technology, showed up at CES 2023 with a cuffless and calibration-free fingertip sphygmomanometer. Last year, Movano Health — which also showed up at CES with a smart ring — announced it completed functional testing for a radio frequency chip that could potentially measure both blood pressure and blood glucose in wearables.
Fitbit’s patent is cool, but the past few months have been lackluster. Its latest smartwatches, the Sense 2 and Versa 4, took a backseat to Google’s Pixel Watch. In addition, features that were available on previous iterations of the watches, such as third-party apps and Google Assistant, are gone. Google has also rebranded the company as “Fitbit by Google” and recently announced that Fitbit users will have to sign in with their Google accounts in a few years. This week, Fitbit experienced several server outages that left users frustrated and angry. All in all, it doesn’t paint a pretty picture.
That’s why it’s hard to see this kind of patent filing as an exciting development. If awarded, it’s more likely to appear in a Pixel Watch than any Fitbit by Google product. And that’s if this feature even sees the light of day anytime soon. While technology moves fast, health technology certainly does not. Wearable tech companies tend to gravitate toward “wellness” features because they don’t need regulatory oversight from the FDA. However, blood pressure would likely necessitate FDA involvement.
At best, this filing is just further proof that non-invasive blood pressure technology is something wearable companies care deeply about. But when and in what form is impossible to predict. It also reminds us that coming up with life-changing health technology is easy, but it is a lot of harder to make it happen. By the time we see widespread wearable blood pressure technology, Fitbit may already be a distant memory.
