A sensor system includes one or more gyroscopes and one or more accelerometers, for measuring subtle motions of a users body. The system estimates physiological parameters of a user, such as heart rate, breathing rate and heart rate variability. When making the estimates, different weights are assigned to data from different sensors. For at least one estimate, weight assigned to data from at least one gyroscope is different than weight assigned to data from at least one accelerometer. Also, for at least one estimate, a weight assigned to one or more sensors located in a first region relative to the users body is different than a weight assigned to one or more sensors located in a second region relative to the users body. Furthermore, weight assigned to data from at least one sensor changes over time.
