The Microsoft Band is making some waves in tech media these days with most initial impression articles giving praise to the new health tracker. Sure, there are some quibbles here and there on design or comfort, which is predictable, but overall, many users seem to be quite happy with their new wrist accessory. Over in our Microsoft Band forums, an interesting question about the Band's heart rate monitoring came up. Specifically, people were wondering what does it mean to monitor your heart rate continuously? I decided to find out and asked Microsoft. On the face of it, this seems obvious but in practice, it can mean many different things. Sampling rate for any technology is something with which we find significant variation. Even when I worked in neuro-labs doing electroencephalograms (EEG), the rate at which the samples are taken, and the amount of channels used varied from lab to lab, experiment to experiment. Best VPN providers 2020: Learn about ExpressVPN, NordVPN & more Another concrete example is video. You could say a video camera records continuously, but this does not tell you anything about the sample rate aka frames per second (FPS). A video camera recording at 5 FPS captures fewer images than one recording at 120 FPS. They are both continuous video but not analogous in terms of richness of data.

The problem Many users have played with the optical heart-rate sensor found on the Microsoft Band, and with different expectations comes different outcomes. Some people found that the band seems to be always 'acquiring' a signal when they tap the Me Tile to see their heart rate. That has led some people to believe that the heart rate monitoring is not working, as it should. Others believe that the Microsoft Band cannot accurately pull in heart rate data from the top of the wrist. Such experiences come from a common misunderstanding of how this technology works. Rates of heart rate data acquisition We asked Microsoft specifically about how often the Band acquires your heart rate, and they were more than happy to provide the information. We asked about three specific scenarios: regular activity/step counting, sleep, and workout/run mode. Here are the three conditions