The emitter and detector of the Basis optical heart-rate monitor are surrounded by four more sensors. Here's a quick tour:
- Accelerometer -- Your heart rate changes frequently during a typical day. Often, these changes are related to activity, but your heart can also race when you're sitting still (remember those surprise questions your high-school physics teacher would ask when you least expected it?). To help differentiate pulse-pounding exercise from pulse-pounding stress, the Basis B1 band comes equipped with an accelerometer -- a device that measures acceleration forces caused by movement. Some accelerometers detect motion along a single axis, but the 3-D version on the Basis band measures motion along three axes. That means it can detect whole-body movement, like the kind you exhibit during exercise or during that recurring nightmare, as well as small-body movement, such as writing or texting.
- Thermometers -- The Basis B1 band includes two sensors for measuring temperature. One detects changes in the wearer's body temperature, the other changes in outside temperature. Taken together, both sensors can provide insights into a person's metabolism. That's because body temperature increases when muscles work, which requires the consumption of more food energy, measured in calories. External temperatures can also influence metabolic processes. For example, when it's cold outside, our bodies expend more energy to maintain body temperatures.
- Galvanic skin response (GSR) sensor -- Human skin is a good conductor of electricity. It's even better when it's wet. The GSR sensor on the Basis B1 band measures the conductivity of a person's skin, which is directly related to how much sweat is present. The skin's moisture output, in turn, reveals a great deal about the wearer's level of exertion during exercise, which, when combined with temperature and heart-rate data, provides a clear picture of how a person responds to different levels of activity.
All of this data flows into the Basis "brain," where complex algorithms look for patterns unique to the wearer's physical activity and cardiac response to that activity. After doing some analysis, the device returns useful metrics, such as calories burned, hours slept, steps taken and heart rate that can help users take action to improve their health and wellness. Additional algorithms on the Basis Web site provide even more analytics and reporting, including how a user stacks up against other Basis participants.
Sound good? Ready to buy? Keep reading.