Abstract: A method for estimating joint angles of a multi-segment limb from inertial sensor data accurately estimates and tracks the orientations of multiple segments of the limb as a function of time using data from a single inertial measurement unit worn at the distal end of the limb. Estimated joint angles are computed from measured inertial data as a function of time in a single step using a nonlinear state space estimator. The estimator preferably includes a tracking filter such as an unscented Kalman filter or particle filter. The nonlinear state space estimator incorporates state space evolution equations based on a kinematic model of the multi-segment limb.

Abstract: Disclosed embodiments include a multi-function wearable apparatus comprising (a) a sensor module including a plurality of low power solid state kinematics sensors,(b) a microprocessor module comprising a low power microcontroller configured for device control, device status, and device communication; (c) a data storage module comprising a solid state local storage medium, said data storage module configured for sampling and storage of kinematics data; (d) a wireless communication module comprising a low power bidirectional transceiver wherein said wireless communication module is configured for communicating and synchronizing sampling time instances of said sensor module with signals from a second apparatus; and (e) a power module comprising a battery and an energy charging regulator. According to one embodiment, the wearable apparatus is a watch capable of quantifying human movement.

Abstract: A method for estimating joint angles of a multi-segment limb from inertial sensor data accurately estimates and tracks the orientations of multiple segments of the limb as a function of time using data from a single inertial measurement unit worn at the distal end of the limb. Estimated joint angles are computed from measured inertial data as a function of time in a single step using a nonlinear state space estimator. The estimator preferably includes a tracking filter such as an unscented Kalman filter or particle filter. The nonlinear state space estimator incorporates state space evolution equations based on a kinematic model of the multi-segment limb.