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Class Action Lawsuit Filed Against Fitbit For 'Highly Inaccurate' Heart Rate Trackers (nbcnews.com)
An anonymous reader quotes a report from NBC News: A class action lawsuit against Fitbit may have grown teeth following the release of a new study that claims the company's popular heart rate trackers are "highly inaccurate." Researchers at the California State Polytechnic University, Pomona tested the heart rates of 43 healthy adults with Fitbit's PurePulse heart rate monitors, using the company's Surge watches and Charge HR bands on each wrist. Subjects were then hooked up to a BioHarness device that produced an electrocardiogram (ECG), to record the heart's rhythm against the data being produced by Fitbit's devices. Comparative results from rest and exercise -- including jump rope, treadmills, outdoor jogging and stair climbing -- showed that the Fitbit devices miscalculated heart rates by up to 20 beats per minute on average during more intensive workouts. The study was commissioned by the Lieff Cabraser, the law firm behind the class action suit that is taking aim at three Fitbit models that use the PurePulse heart monitor, including the Fitbit Blaze, Fitbit Charge HR and Fitbit Surge. "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," Fitbit said in a statement posted by Gizmodo.
Right... Companies shouldn't be held accountable just because they made a crap product that advertises functionality that it doesn't have. It's all those idiot users' fault for believing that consumer protection laws should require a product to do what is advertised.
FitBit and others did not claim to be medical devices but rather a way to keep track of your activity as part of a wellness regime. Now, a paid study finds that they are not as accurate as medical devices and somehow the company is defrauding the consumer? I have a number of issues with FitBit including their desire to have me send them my exercise information rather than just load it into the app and they are itchy and uncomfortable. It would be nice to see the raw data on which the conclusions are based to see what "up to 20 beats" really means and how accurate FitBit is in various situations.
I would expect if someone is undergoing a severe exercise regimen the would carefully research the tools they use to track vital signs to ensure their safety. If I were on a jury and someone said "I was injured because my FitBit didn't tell me my heartbeat was too high while I did this extreme workout..." I'd respond with a "Sorry, but the legal system can't fix stupid, but mother nature can and did" judgement.
Part of the problem is we expect computers to be precise and accurate and they often are not, and when they aren't people get upset instead of adjusting their expectations.
I'm a consultant - I convert gibberish into cash-flow.
"Well, then. I was thinking of getting one to help me get and stay close to max-rate for interval training. 14% inaccuracy would be wildly dangerous in that case."
I do hope you're being sarcastic. If not then you might want to consider listening to your body instead of reliying on some stupid device. You know, what athletes people have done for millenia. If you're so disconnected from what your body is telling you perhaps you shouldn't be training at all.
The lawyers sponsored the study, and it looks like it's actually pretty decent methodology--comparing the pulse from the EKG (which I certainly hope is reliable) to the FitBits on the wrists at the same time means you've got one of the gold standards of study design, since the pulse ought to be the same in the same person no matter what point you measure it from (and how you measure it) so you make it a lot easier to analyze the data. You've controlled both for the issues if you used different subjects and for if you measured at different times, so the only real question when doing the analysis is "How well do the parts of each set align?" (You do multiple subjects to make sure you didn't have something rather weird happen like somebody somehow pulling off 'different pulse depending on where measured,' and the number looks actually rather good--a bit more subjects than I'd expect a study like this without money being thrown at it to have, actually.)
The only thing that seems particularly weird here is that I'd have expected the company to have sponsored this study or something very much like it during its own R&D cycle, because it would be both good for marketing and good practices. Doing this sort of basic study is pretty...basic, if you're trying to make something that monitors {foo}. About the only reason I could see for not doing that would be "FDA might get panties in a wad," except that is something that I'm amazed hasn't happened already...and I would be wanting to develop a medical-grade version anyway. It should sell, especially if I can add in remote monitoring; that would probably net me sales to both health care facilities and in professional sports...