Patent ID: 7634379

Claim:
An apparatus for monitoring posture and acceleration of a user, said apparatus being mountable to said user, comprising: a multi-axis sensor operative to sense gravity and acceleration along a plurality of axes by measuring a projection of an apparent gravity vector on each of said plurality of axes, said apparent gravity vector having a first component corresponding to an actual gravity vector and a second component corresponding to an acceleration vector, said actual gravity vector having a magnitude equal to 1 g; at least one memory operative to store data representative of the measured apparent gravity vector; and at least one processor operative to process the data stored in said at least one memory, said at least one processor being operative: to calculate a representation of the measured apparent gravity vector; to calculate, from said representation of the measured apparent gravity vector and said magnitude of said actual gravity vector, a representation of said actual gravity vector said actual gravity vector having an associated direction; to subtract said representation of said actual gravity vector from said representation of the measured apparent gravity vector to obtain a representation of said acceleration vector, said acceleration vector having an associated magnitude and an associated direction; and to generate at least one indication of one or more of the posture of said user based at least upon the direction of said actual gravity vector, and the acceleration of said user based at least upon the magnitude and the direction of said acceleration vector.