SYSTEM AND METHOD FOR AUTOMATIC POSTURE CALIBRATION

1 . A method for posture feedback comprising:

collecting kinematic data by an activity monitoring device coupled to a user;

calibrating the kinematic data to a base walking orientation of the activity monitoring device, which comprises:

detecting a walking activity state through the kinematic data, and

when a walking activity state is detected, generating the base walking orientation from kinematic data;

setting a posture correction factor;

measuring user posture with the calibrated kinematic data;

triggering posture feedback based on the user posture adjusted by the posture correction factor.

2 . The method of claim 1 , wherein setting a posture correction factor comprises receiving a calibration event signal through the activity monitoring device.

3 . The method of claim 2 , wherein setting a posture correction factor further comprises measuring user posture over a sustained period in response to the calibration event signal, and setting the posture correction factor as an average of measured user posture during multiple calibration events.

4 . The method of claim 2 , wherein setting a posture correction factor further comprises measuring user posture over a sustained period in response to the calibration event signal, and setting the posture correction factor as a result of machine learning analysis of measured posture of multiple users.

5 . The method of claim 2 , further comprising classifying the calibration event signal and rejecting calibration events classified as false calibrations.

6 . The method of claim 2 , further comprising classifying the calibration event signal and suspending posture feedback during a posture state where a calibration event is classified as a silencing event.

7 . The method of claim 2 , wherein the activity monitoring device is attached to an article of clothing of a user and the calibration event signal is triggered by the activation of an input on the activity monitoring device.

8 . The method of claim 1 , wherein calibrating the kinematic data to a base walking orientation comprises recalibrating the kinematic data to an updated base walking orientation upon subsequently detecting walking.

9 . The method of claim 8 , wherein calibrating the kinematic data to a base walking orientation further comprises recording kinematic data during the walking activity state for at least five steps.

10 . The method of claim 1 , further comprising detecting a sitting activity state, wherein measuring user posture with the calibrated kinematic data is measured during the sitting activity state.

11 . The method of claim 1 , further comprising setting at least a second posture correction factor, wherein the first posture correction factor is for a first activity state and the second posture correction factor is for a second activity distinct from the first activity state; and wherein triggering posture feedback comprises triggering posture feedback based on the user posture adjusted by the first posture correction factor when in a first activity state and triggering posture feedback based on the user posture adjusted by the second posture correction factor when in the second activity state.

12 . The method of claim 1 , wherein generating the base walking orientation from kinematic data comprises correcting pitch and roll of the kinematic data.

13 . The method of claim 11 , wherein generating the base walking orientation from kinematic data comprises correcting yaw of the kinematic data.

14 . A system for posture feedback comprising:

an activity monitoring device that couples to a user that includes

an inertial measurement unit that collects kinematic data,

user feedback mechanism, and

a processor; and

wherein the processor is configured to:

detect a walking activity state through the kinematic data,

calibrate the kinematic data when in the walking activity state,

set a posture correction factor,

measure user posture, and

activate the user feedback mechanism based on the user posture adjusted by the posture correction factor.

15 . The system of claim 14 , wherein the activity monitoring device further comprises a calibration input; and wherein the processor is further configured to:

detect a calibration event signal triggered by the calibration input,

measure user posture over a sustained period in response to the calibration event signal, and

set the posture correction factor as an average of measured user posture during multiple calibration events.

16 . The system of claim 15 , wherein the calibration input is a button, and the user feedback mechanism is vibrational actuator.

17 . The system of claim 14 , wherein the activity monitoring device further comprises a calibration input; and wherein the processor is further configured to:

detect a calibration event signal triggered by the calibration input,

measure user posture over a sustained period in response to the calibration event signal, and

set the posture correction factor as a machine learning analysis of measured posture of multiple users.

18 . The system of claim 14 , wherein the processor is configured to classify the calibration event signal and suspend activation of the user feedback mechanism where a calibration event is classified as a silencing event.