Over the past few years, it’s clear that wearable makers are setting their sights beyond heart rate tracking. More smartwatches and fitness trackers sport SpO2 sensors, for example, as a means of either monitoring for sleep apnea or keeping tabs on stress. But if there’s one ailment most wearable companies are stumped by, it’s blood pressure. After a few years of hinting at it, Valencell, a well-known wearables components-maker, now says it’s only a matter of time before we start seeing blood-pressure monitoring earbuds.
Why now? Well, that’s because Valencell says it’s somehow figured out how to get a teeny tiny PPG sensor – the same optical sensors used in wrist-based wearables to measure heart rate – to measure blood pressure. Accuracy-wise, Valencell says its tech should be on par with automated cuffs, meets the ISO accuracy standards, and should be able to correctly identify hypertension with 89 percent accuracy. To back that up, Valencell said it collected 15,000 datasets from over 5,000 subjects. To take things a step further, Valencell said it then conducted another round of validation tests in accordance with ISO protocol, using data collected by non-Valencell employed nurses. What’s fascinating, however, is that Valencell’s sensor doesn’t require any sort of calibration.
Calibration is the thing that makes blood pressure wearables so tricky to develop in the first place. A manual test, for instance, involves inflating a cuff until you can hear the subject’s heartbeat and then slowly deflating it until you can’t anymore. Automated cuffs essentially do the same thing but eliminate the need for another human to take a reading. Creating wearables that can mimic this procedure is tough; Omron did it with their HeartGuide smartwatch, which features an inflatable strap, but it took nearly two years of testing before it could gain FDA clearance.
Conversely, Valencell claims its sensor only needs three things to take a blood pressure reading in 30 seconds: a PPG signal, motion signal, and static biometrics like age, weight, height, and gender. As an added bonus, Valencell says its sensor can measure blood pressure in real-time, continuously. It also says the ear (provided you can get the correct fit) is the ideal place to get blood pressure measurements, as there’s more blood flow to the area and remains a fixed distance from your heart.
A demo of Valencell’s tech in action. Blood pressure readings take only 30 seconds.
High-blood pressure, or hypertension, is often referred to as ‘the silent killer,’ precisely because so few people know they have it. The Center for Disease Control says 75 million people have hypertension, but that only half are aware. Another issue with tracking it is that traditional methods are only spot-checks. Continuous monitoring, however, would open up doors to new applications.
That being said, Valencell was keen to point out its sensor isn’t meant to be a medical-grade solution – it’s intended more as a general wellness tool. One use case Valencell highlighted was meditation apps like Calm or Headspace. Since those are audio-based anyway, you’d be able to theoretically track how your blood pressure is impacted during meditation via your ear. Likewise, you could use blood pressure earbuds to screen for the likelihood of hypertension. So, it wouldn’t be a diagnostic tool, but rather something that could spur someone to get themselves checked out by a doctor. Blood pressure, Valencell says, is a better measure of stress than blood oxygen saturation (the metric measured by SpO2 sensors) on the theory that it’s a more direct indicator of the quality of your health. Hypertension is generally a sign something is wrong. Meanwhile, a wonky SpO2 reading could have numerous benign reasons.
This isn’t the first year that Valencell has pitched blood pressure monitoring via PPG sensors. The company has been working on it since 2009, and I remember chatting with them about it back during CES 2018. The difference is, now the tech is ready to be commercialised. When I asked Valencell when we could see a pair of earbuds with this tech hit the market, its president, Dr. Steven LaBoeuf, said it was highly likely before the end of the year.
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