How Does a Fitness Tracker Know You are Asleep?

Fitness trackers are gadgets which monitor different parameters of the body’s functioning. They can tell you how many steps you have taken during a day. Or measure the number of calories that have been burned by physical activity. They can keep track of the heart beats during the entire twenty four hour period and let you know when the blood pressure rises and falls. They can even tell you just how well you are sleeping at night.

Now that brings me to the question, how does the inanimate sensor based gadget that is worn on the wrist know when the wearer is awake or asleep? Yes some have a special sleep mode which allows them to compute the data gathered during that period differently as compared to when the wearer is awake and active.

The truth is the sensor does not know that you are asleep. It just does what it always does, collect data on your body’s movement and pass it on to the software that analyses it. It is the software based algorithms that actually are able to ascribe the sleep pattern based on how they have been programmed. Now it would be a long science project to make that algorithm perfect!