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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.
Wow...only a day or so after that study was released and the lawyer vultures are already circling.... smh...
You're messin' with my Zen Thing, man.....
These devices were designed by Nathan Myhrvold. They are accurate but you have the wrong pulse.
Some drink at the fountain of knowledge. Others just gargle.
Expect the prices of these things to soar as their liability insurance costs far outweigh their costs of production and advertising.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
The fallout from this will be regardless of whether or not the disclaimer was there, but rather NO MEDICAL ANALYSIS can be performed on a non-certified device!! This is just paving the way for future legislation to solidify that notion. What will be interesting - and bring a big fucking bag of popcorn - is how both Google and Apple will team up against Federal regulatory action. You want to talk about political nuclear war, baby, this would be it; right up there with encryption!
Life is not for the lazy.
Overpriced fad gadgets turn out to be crap - film at 11.
They may indeed be crap, but the crappy article provides no actual information about that. First, it says it is inaccurate by an average of "up to" 20 beats per minute. "Up to" means "less than", so that statement would be true even if the deviation was zero. So why don't they just say what the average deviation is, instead of using meaningless weasel words? Then later in the article, they talk about an error of "20 or 30" beats per minute. So which is it? Less than 20, or 20 to 30? TFA was written by someone willing to twist both words and numbers to push an agenda.
I was wondering why Garmin (FitBit competitor) was proeminently displaying the disclaimer below on their Web site.
Now I know why..
Activity Tracking Accuracy
Garmin activity trackers are intended to be tools to provide you with information to encourage an active and healthy lifestyle. Garmin activity trackers rely on sensors that track your movement and other metrics. The data and information provided by these devices is intended to be a close estimation of your activity and metrics tracked, but may not be completely accurate, including step, sleep, distance, heart rate and calorie data. Garmin activity trackers are not medical devices, and the data provided by them is not intended to be utilized for medical purposes and is not intended to diagnose, treat, cure, or prevent any disease. Garmin recommends you consult your doctor before engaging in any exercise routine.
Accuracy of Wrist-based Heart Rate (Elevate)
The optical wrist heart rate (HR) monitor for Garmin wearables is a valuable tool that can provide an accurate estimation of the user’s heart rate at any given point in time. The optical HR monitor is designed to attempt to monitor a user’s heart rate 24 hours a day, 7 days a week. The frequency at which heart rate is measured varies, and depends on the level of activity of the user. When you start an activity with your Garmin optical HR device, the optical HR monitor provides feedback more frequently as the optical sensor is on all of the time and is trying to measure heart rate on a continuous basis during a given activity period. The intent is to provide the user with a more frequent and accurate heart rate reading during a given activity.
While our wrist HR monitor technology is state of the art, there are inherent limitations with the technology that may cause some of the heart rate readings to be inaccurate under certain circumstances. These circumstances include the user’s physical characteristics, the fit of the device and the type and intensity of the activity as outlined above. The HR monitor data is not intended to be used for medical purposes, nor is it intended to diagnose, treat, cure or prevent any disease or condition.
http://www.consumerreports.org...
The new testing confirmed our earlier results: Both the Charge HR and Surge were very accurate when compared to the reference Polar H7 ECG monitor. During nearly every trial, the variance between the chest strap and the Fitbit devices amounted to no more than three heartbeats per minute.
However, there was one exception: When our female tester wore the Fitbit Charge HR on her wrist and got up to higher intensity levels, the margin of error crept upwards. During one run, when the chest strap read 150 bpm, the Fitbit Charge HR read 144 bpm. During the second run, the device read only 139 bpm. That problem went away when she wore the Charge HR on her forearm. (And the Fitbit Surge was accurate no matter how it was worn.)
I'm sure there's plenty of caveat emptor to go around, but the very first thing I did when I got my Charge HR was to test it by taking my pulse myself and comparing it to the fitbit number.
The resting heart rate is dead on. (not their calculated resting heart rate--that's a dumb, arbitrary number they come up with, but the real time resting heart rate is accurate.)
I've had a few troubles with the workout heart rate, but not because it can't count, but because the wristband moves around after sweat dislodges it. It can slip down my wrist and the sensor will lose contact with my skin. But when that doesn't happen, the number is pretty close.
For a while at first, I wore my under armor heart rate monitor on my chest along with the fitbit, and they were pretty much in sync, too.
This lawsuit is why we can't have nice things.
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...
Seems easy to do, doesn't it? You take the reciprocal of the interval between heartbeats scale that to beats per minute and there you go.
Except if you've ever designed software and had to look at a problem like this, you'll understand that it's not nearly so simple. The heart isn't nearly precise as the quartz oscillator you're using for your timing reference. Sometimes it throws in an early beat or late one, because it's an electro-chemo-mechanical oscillator that works by the flow of ions across a membranes of countless cells. So the rate is going to jump around a little bit second to second, which will only confuse the user. What's more any sensor that isn't stuck on with adhesive is going to miss a few signals now and then, or maybe get a spurious one.
So what you do is take a moving average to smooth out all the kinds of noise you have in your signal. Having a fitbit myself, I find it surprisingly accurate when compared against a manual pulse when your heart rate is steady. Watching the figures as I exercise hard, it's clear there's a lag in response as your heart rate accelerates in particular (since the heart slows this is less of a problem as you slow down), which indicates that the device is giving me some kind of moving average.
And it's OK. The point is to give users useful feedback about how their heart is doing during periods of strenuous exercise, not to give them a beat by beat accounting of what the sensors are picking up. It doesn't have to be laboratory-precise or instantaneous because there's nothing useful users can do with that precision. I've lost count of many times have I had to explain these two things to clients: you don't need feedback that's an order of magnitude faster than you're capable of responding too, and you shouldn't take action based on statistical noise; data doesn't have to be perfectly precise, they just have to tell you whether you're in the right ballpark or headed in the right direction.
The fitbit works very well for the purpose it's intended and the way users use it. You take a series of readings (which are sometimes off, but recognizably so) to establish what your heart is doing, and then shift to a new level of effort and take several readings as your heart settles into a new equilibrium.
Anyhow, note the weasel phrase "Up to 20 beats per minute." This means in all their testing the very worst discrepancy they ever found between the readings taken from glued on electrodes from the loosely cinched bracelet monitor was 20 beats per minute. That actually sounds pretty good to me for a worst case result.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
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.
The company's website has a lot to say about how the type of exercise, range of motion, and the way the device is worn can affect the accuracy of heartbeat measurement, and they make no claims at all regarding measurement accuracy. It doesn't appear to me that they are advertising great accuracy at all. Aside from that, this is not a case of the company running afoul of consumer protection laws; it's a case of lawyers seeking a profit from a dodgy class-action suit. The consumers who were putatively damaged won't see much in the way of an award, which is the norm in cases like this.
"miscalculated heart rates by up to 20 beats per minute"
"Up to" -- like "as much as" -- is a marketing phrase, not a description of results. I haven't read the study -- I didn't see any useful information in the linked NBC News article as to how to find it.
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.
The company's website has a lot to say about how the type of exercise, range of motion, and the way the device is worn can affect the accuracy of heartbeat measurement, and they make no claims at all regarding measurement accuracy. It doesn't appear to me that they are advertising great accuracy at all. Aside from that, this is not a case of the company running afoul of consumer protection laws; it's a case of lawyers seeking a profit from a dodgy class-action suit. The consumers who were putatively damaged won't see much in the way of an award, which is the norm in cases like this.
What's the damage though? Like you say it's a device that gives you and indication of what your heartrate is. I've never heard them (or apple etc) guarantee any kind of accuracy and they don't claim it's medical grade in the slightest. With all that though. What its the damage this class action seeks to compensate? It seems if you need to know your exact heart rate for whatever reason, a fitbit might not be the right tool for the job.
Wanna buy a shirt?
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Exactly how has this harmed anyone?
Everyone knows pedometers aren't accurate. This is just a continuation of what we all knew in the 1980s and 1990s.
I don't see how this lawsuit has any merit whatsoever. Whom has it harmed, and how?
What about all the other pedometers, like the ones health insurance companies issue to employees with which points are earned to obtain discounts?
Kriston