I agreed with above posts that fitbit should not consider for FDA approval unless if fitbit claims to treat or diagnose other specific diseases then definitely need a FDA approval and I believe it considers as a class II device and need to fill out 510K form. But as far fitbit only use as monitoring heart rate and FDA opted not to regulate any general wellness device. According to one article, a test concluded very accurate when compared to a chest strap heart rate monitor, but the study was biased due to a small sample size of just two participants which I think a major failure. There always be some differences on measuring heart rate because in medical-grade devices typically worn around the chest to measure electrical impulses that travel through the heart, while fitbit detects blood activities in the wrist to measures one’s heart rate. There were several fitness tracker devices that measured heart activities before fitbit were inaccurate.Those devices like fitbit are only for tracking life activities, but one should not be rely on.