Study alleges Fitbit’s heart rate tech is wildly inaccurate, ambiguous and ‘all over the place’ [UPDATE]

It looks like activity tracker pioneer and wearable market leader Fitbit has much more important things to worry about than declining profits and prospectively stagnating sales, as a class action lawsuit filed a few months ago may end up greatly harming the company’s reputation.

We’re probably way past the silently settling phase too, with a lot of fingers pointed at the Charge HR, Surge and Blaze for erratically and imprecisely monitoring heart rate information which can “pose a danger to not only the clinical population, but those population of individuals who may not know that they have any cardiac related conditions.”

While Fitbit doesn’t advertise its consumer products as medical-grade devices, the PurePulse HR technology is without a doubt a major selling point for many of the San Francisco outfit’s wildly successful fitness bands and watches.

But according to a so-called “validation study” conducted by an unbiased independent researcher, a Dr. Edward Jo from the California State Polytechnic University, the data reported by the three wearable gadgets in question is not just in average off by 20 beats per minute compared to a separate, much more precise heart rate supervisor, but also “sporadic”, “ambiguous”, and “all over the place.”

That’s to say there are big inconsistencies between Fitbit’s own devices, and the difference in monitored health information is by no means “systematic.” Otherwise put, the Surge could occasionally get your heart rate wrong by 20 BPM, and the Charge HR by 30 or 40, although they technically use the same exact sensors and hardware.

In response, Fitbit predictably disputed the findings of the research, calling the study “biased, baseless, and nothing more than an attempt to extract a payout” from the company. The neutrality of the lead researcher is contested, the methodology is deemed as “flawed”, and the electrocardiogram used to double-check the accuracy of the Charge HR, Surge and Blaze’s HR monitors is labeled “consumer-grade”, and thus unreliable.

One thing’s crystal clear – this legal brawl just got ugly, and it’s far from over.

Update: A Fitbit spokesperson reached out with a more thorough counter-statement, which we’re citing in full as follows:

“What the plaintiffs’ attorneys call a “study” is biased, baseless, and nothing more than an attempt to extract a payout from Fitbit. It lacks scientific rigor and is the product of flawed methodology. It was paid for by plaintiffs’ lawyers who are suing Fitbit, and was conducted with a consumer-grade electrocardiogram – not a true clinical device, as implied by the plaintiffs’ lawyers. Furthermore, there is no evidence the device used in the purported “study” was tested for accuracy.

Fitbit’s research team rigorously researched and developed the technology for three years prior to introducing it to market and continues to conduct extensive internal studies to test the features of our products. Fitbit Charge HR is the #1 selling fitness tracker on the market, and is embraced by millions of consumers around the globe.

Consumer Reports independently tested the heart rate accuracy of the Charge HR and Surge after the initial lawsuit was filed in January and gave both products an “excellent” rating. We stand behind our heart-rate monitoring technology and all our products, and continue to believe the plaintiffs’ allegations do not have any merit. We are vigorously defending against these claims, and will resist any attempts by the plaintiffs’ lawyers to leverage a settlement with misleading tactics and false claims of scientific evidence.”

Source: Wareable

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About The Author
Adrian Diaconescu
Adrian has had an insatiable passion for writing since he was in school and found himself writing philosophical essays about the meaning of life and the differences between light and dark beer. Later, he realized this was pretty much his only marketable skill, so he first created a personal blog (in Romanian) and then discovered his true calling, which is writing about all things tech (in English).