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Lawsuit Accuses Fitbit of Lying about Heart Monitor Accuracy

Article-Lawsuit Accuses Fitbit of Lying about Heart Monitor Accuracy

Things might not be so rosy for Fitbit in 2016. The company's stock tanked after its most recent product introduction and now the company is facing a class-action lawsuit alleging that its heart-rate monitors are inaccurate and, therefore, dangerous. 

Brian Buntz

Fitbit ad purportedly showing the device being used to monitor heart rate during a strenuous workout.
Fitbit ad purportedly showing the device being used to monitor heart rate during a strenuous workout.

A class-action lawsuit accuses Fitbit of lying about the accuracy of their heart-rate monitoring technology. The suit claims that that the company's Charge HR and Surge fail to count every beat, despite claims that the device is accurate at measuring heart rate--even when users are working out.

According to the suit, a board-certified cardiologist concluded that two Fitbit models were inaccurate by testing their measurements against those from an EKG. The cardiology reported that, for heart rates greater than 100 beats per minute, Fitbits were off by an average of 24.34 beats per minute; some readings, however, were off by as much as 75 bpm.

One of the plaintiffs in the case alleges that her Charge HR device stated that her heart rate was in reality nearly twice as high than the device measured: while her personal trainer had gauged her heart rate at 160 bpm, the Charge HR reported it at 82 bpm. "Plaintiff [Teresa] Black was approaching the maximum recommended heart rate for her age, and if she had continued to rely on her inaccurate PurePulse Tracker, she may well have exceeded it, thereby jeopardizing her health and safety," reads the complaint.

Another plaintiff, Kate McKlellan, PhD, states that she bought a Fitbit Charge HR after seeing an advertisement for the device touting the accuracy of its heart rate monitor. She then noticed that the device didn't deliver accurate results during exercise after  comparing data from the Fitbit with stationary cardiovascular exercise machines. She then sought to obtain a refund for the device from the manufacturer but was denied it.

The final plaintiff named in the case, David Urban, a fitness enthusiast with a family history of heart disease, purchased a Fitbit Surge. During workouts, Urban sought to keep his heart rate under 160 bpm at the behest of his doctor, but he noticed that the device didn't seem to log heart rates of more than 125 bpm--at even at high intensities. He then cross-referenced the measurements with a chest-strap based heart rate monitor and found the readings of that device to be between 15-25 bpm higher. 

The lawsuit reports that Fitbit admitted to some of the members of the class action lawsuit that the technology is inaccurate at measuring the pulse during high-intensity workouts.

There is certainly a demand for convenient heart-rate tracking. The traditional technology for the purpose--chest-based straps are often uncomfortable.            

In its promotional materials, Fitbit says that its PurePulse heart rate monitor accurately gauges heart rate using LED lights to detect changes in capillary blood volume. Using "finely tuned algorithms," the company can "measure heart rate automatically and continuously" and allow users to "accurately track workout intensity."

The lawsuit also cites 10 Amazon reviewers who complain about the accuracy of the Fitbit devices' heart-rate-tracking ability and one saying that the technology randomly stops working during workouts. Another reviewer explains: "If you are buying the HR version you are essentially just buying a more expensive Charge that has two green lights on the back and has a nicer strap because the heart rate function is useless."

Learn more about cutting-edge medical devices at MD&M West, February 9-11 at the Anaheim Convention Center in Anaheim, CA.

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