Fitbit Heartbeat and how is it a defeat device

[Agnibaan]

Those who are aware of Volkswagen defeat device case would relate to this. I have seen my heartbeat jump very high when I pat my baby to sleep and it has been relatively low when I am slowly hiking on a steep slope (noticed it during Vernal fall hike, Yosemite) barely making it. In both the cases, I have measured my pulse rate (counting pulsation on my wrist and a stop watch) and Fitbit was way off. In the first case it showed 150 against 80 (actual) and in the second case it was 115 vs 145 (actual)

Sensor works for sure and it is generally accurate but aiding the measurement using hand movement feels like a very unscientific way to make these devices. For sure during high motion, sensors may not work accurately, but using other signals to predict it just a hogwash.

[Guy_]

Hi @Agnibaan - some Fitbit watches with the new technology sensor don't like repetitive movements, mine counts almost double at times, others mention them under reading as well. It can vary depending on many things but is generally fairly reasonable at rest and for sleep.