Fitbit, of the US, is now one month in to its ongoing blood-pressure study for wristworn wearables.

Fitbit is exploring whether Pulse Arrival Time (PAT) can be used to track blood pressure on the wrist (source).

PAT measures the time taken from a heartbeat in the chest to reach a pulse in the wrist. The longer the time-taken, the higher or lower the blood pressure.

But PAT is not an easy metric to measure. The body jiggles around a lot, arms wave about, and measurements last a fraction of a second.

It will be interesting to see the final results of the study. Consumers worldwide, young or old, definitely have high interest in blood-pressure tracking. For example, a recent survey from our UX division found it to be a top-10 feature of high importance in Europe. Our full survey is published here.