Lawsuit Claims Fitbit Devices Dangerously Underestimate Heart Rate

With some Fitbit devices, every beat may not get counted, according to claims in a proposed nationwide class action lawsuit filed Tuesday.

Three plaintiffs claim that their Fitbit wrist-based heart monitors, “Charge HR” and “Surge,” do not and cannot accurately measure heart rate as advertised. Those sales pitches claim that both products, which are sold for around $150 and $250, respectively, can continuously and accurately monitor heart rate, even during exercise—under tag lines such as “every beat counts.” But the lawsuit claims that the heart rate monitors, which tout “PurePulse Tracker” technology, seem particularly incapable of accurately measuring elevated heart rates, often reading dangerously underestimated rates during workouts.

Source: Lawsuit claims Fitbit devices dangerously underestimate heart rate

I’m not surprised – I’ve been reading a lot of the Heart Rate Monitors (HRMs) that use LEDs at the wrist rather than the chest strap.  The DCRainMaker reviews for the Surge and Charge HR also demonstrated inaccuracy to the point of being useless.  Either Fitbit will be accountable (unlikely), or they’ll update packaging…  DCRainMaker has more information and good points about the suit.

That said, the article says the suit claims using LEDs for HRM is useless but that’s not true.  Mio has had the tech and patents for a while – they recently licensed to Garmin for the FR225, which is the most accurate new wearable to date.  Sadly, the FR225 was supplanted after only 4 months on the market with the FR235… which uses the Garmin sensor, that is noticeably less accurate.