Gait measurement with 3-axes accelerometer/gyro in mobile devices
The present invention relates to a method of gait measurement using tri-axial accelerometer/gyro in mobile devices. In particular, the present invention relates to a method of gait measurement using tri-axial accelerometer/gyro in mobile devices for monitoring and improving the physical movement of a moving subject.
1. A method for real-time measurement of gait imperfection in a human subject, the method comprising:
placing a mobile communication device against a lower back of said human subject, wherein the mobile communication device is equipped with a tri-axial accelerometer or a gyro;
measuring in real-time under a sampling frequency, by the mobile communication device, walking, heaving and lateral movements of said human subject, wherein the sample frequency is determined based on a movement pattern of the human subject;
constructing in real-time a signature of said subject based on movements measured by the mobile communication device;
wherein the signature is a three-dimensional trajectory in orthogonal directions of said subject's center of gravity's acceleration trajectory, the three-dimensional trajectory comprising direction and magnitude of acceleration components of the movements, and phase relationships between the acceleration components of the movements in different directions;
constructing in real-time a power level (W ij ) dispensed by said subject to keep balance during motion quantitatively based on said signature by computing a summation of forces associated with individual segments along a trajectory of the center of gravity of said subject divided by a total measurement time; and
generating an output to indicate the gait imperfection in the human subject, wherein the generated output comprises the constructed signature and the constructed power level.
2. The method according to claim 1 , wherein said signature is used in monitoring, diagnosing and improving the movement performance of said human subject.
3. The method according to claim 1 , wherein said signature is used in monitoring the progress of physical rehabilitation or physical well-being or both of said human subject via the movement of said human subject.
4. The method according to claim 1 , wherein said signature is used in the designing or fitting of prosthesis or both for said human subject.
5. The method according to claim 1 , wherein said signature is used as a biometric identifier of said human subject.
6. The method according to claim 1 , wherein said signature is used as an indicator for physical impairment analysis of said human subject.
7. The method according to claim 1 , wherein said signature is used as an identifier for selecting human subjects with better form of movement.
8. The method according to claim 1 , wherein said signature is used in designing of footwear for said human subject.
9. The method according to claim 1 , wherein said signature is used as an indicator in the fitting and selecting footwear for said human subject.
10. The method according to claim 1 , wherein said signature is used in the designing of an exercise equipment for said human subject.
11. The method according to claim 1 , wherein said signature is used in the designing of backpacks and other forms of carry luggage for said human subject.
12. The method according to claim 1 , wherein said sampling frequency is 100 Hz or higher.
13. The method according to claim 1 , wherein sensitivity of said tri-axial accelerometer or gyro is approximately 0.003 g.
14. The method according to claim 1 , further comprising:
formulating a reference table of a plurality of said power levels of a plurality of human subjects with a plurality of fitness levels under a plurality of conditions;
measuring gait imperfection of said human subject based on the obtained power level of said human subject in reference to said reference table; and correcting said gait imperfection of said human subject through external activity.
15. An apparatus for real-time measurement of gait imperfection in a human subject comprising:
a mobile communication device having a tri-axial accelerometer or a gyro placed against a lower back of said human subject and configured to measure in real-time under a sampling frequency walking, heaving and lateral movements of said human subject, wherein the sample frequency is determined based on a movement pattern of the human subject;
a computer processor configured to:
constructing in real-time a signature of said subject based on movements measured by the mobile communication device;
wherein the signature is a three-dimensional trajectory in orthogonal directions of said human subject's center of gravity's acceleration trajectory, the three-dimensional trajectory comprising direction and magnitude of acceleration components of the movements, and phase relationship between the acceleration components of the movements in different directions; and
constructing in real-time a power level dispensed by said human subject to keep balance during motion quantitatively based on said signature by computing a summation of forces associated with individual segments along a trajectory of the center of gravity of said human subject divided by a total measurement time; and
generating an output to indicate the gait imperfection in the human subject, wherein the generated output comprises the constructed signature and the constructed power level.