ACCELEROMETER-BASED GAIT ANALYSIS
Embodiments of systems and methods determine one or more gait parameters using acceleration readings generated by an accelerometer coupled to a user. Gait parameters determined by various embodiments may include step length, step width, step time, single limb support time, or double limb support time. The accelerometer may be coupled to one of the user's arms. Exemplary systems may comprise an accelerometer, a processor, and a non-transitory computer readable medium (NTCRM). The processor may process acceleration readings from the accelerometer according to instructions stored on the NTCRM to determine the one or more gait parameters. The processor may communicate the one or more gait parameters to a receiving device. Some embodiments of the system may function as self-contained units and some embodiments may present information corresponding to gait parameters or recommendations regarding gait.
1 - 33 . (canceled)
34 . A device for determining a step width of a user based at least in part on acceleration data comprising a plurality of acceleration readings, the device comprising at least one processor and at least one memory comprising instructions, the at least one memory and the instructions configured to, with the at least one processor, cause the device to at least:
receive the plurality of acceleration readings, wherein the plurality of acceleration readings is generated by an accelerometer measuring acceleration of the user's arm, wherein (a) the plurality of acceleration readings is associated with acceleration along each of two or more orthogonal axes, and (b) at least one of the two or more orthogonal axes is parallel to the mediolateral anatomical axis of the user and is a z axis;
identify a first time at which a first combined reading was generated, wherein the first combined reading (a) is a lowest local minimum reading during a first window, and (b) comprises readings of at least two of the two or more orthogonal axes generated at a first time;
identify a second time at which a second combined reading was generated, wherein the second combined reading (a) is a first occurring reading to exceed a threshold after the first reading, and (b) comprises readings of at least two of the two or more orthogonal axes generated at a second time;
determine a step width of the user based at least in part on a double integral of readings associated with acceleration along the z axis from the first time to the second time; and
provide data associated with the step width to a recipient device, wherein the recipient devices provides a perceivable indication associated with the data.
35 . The device of claim 34 , wherein the at least one memory and the instructions are further configured to, with the at least one processor, cause the device to at least determine a fundamental frequency using an autocorrelation function applied to the plurality of acceleration readings and in which the duration of the first window is a fraction of the fundamental frequency.
36 . The device of claim 34 , wherein the at least one memory and the instructions are further configured to, with the at least one processor, cause the device to at least only determine the step width in an instance in which none of the plurality of readings associated with acceleration along the z axis from the first time to the second time exceeds the threshold.
37 . The device of claim 34 , wherein the at least one memory and the instructions are further configured to, with the at least one processor, cause the device to at least multiply the double integral of readings by a coefficient to determine the step width.
38 . The device of claim 37 , wherein the coefficient is proportional to the length of one or more of: an arm of the user; a leg of the user; a height of the user; or a measure of the user's body.
39 . The device of claim 34 , wherein the at least one memory and the instructions are further configured to, with the at least one processor, cause the device to at least compare step widths of one or more even numbered steps to step widths of one or more odd numbered steps to determine a measure of symmetry and provide data associated with the measure of symmetry to the recipient device.
40 . The device of claim 34 , wherein the at least one memory and the instructions are further configured to, with the at least one processor, cause the device to at least:
determine a variability measure of a plurality of step widths; and
provide data associated with the variability measure to the recipient device.
41 . The device of claim 34 , wherein the recipient device comprises at least one of:
a non-transitory computer-readable medium;
a recipient device communicatively coupled to the at least one processor using a network;
an electromagnetic transmitter; or
a user interface.
42 . A method for determining a step width of a user based at least in part on acceleration data comprising a plurality of acceleration readings, the method comprising:
receiving, by one or more processors of a device, the plurality of acceleration readings, wherein the plurality of acceleration readings is generated by an accelerometer measuring acceleration of the user's arm, wherein (a) the plurality of acceleration readings is associated with acceleration along each of two or more orthogonal axes, and (b) at least one of the two or more orthogonal axes is parallel to the mediolateral anatomical axis of the user and is a z axis;
identifying, by the one or more processors of the device, a first time at which a first combined reading was generated, wherein the first combined reading (a) is a lowest local minimum reading during a first window, and (b) comprises readings of at least two of the two or more orthogonal axes generated at a first time;
identifying, by the one or more processors of the device, a second time at which a second combined reading was generated, wherein the second combined reading (a) is a first occurring reading to exceed a threshold after the first reading, and (b) comprises readings of at least two of the two or more orthogonal axes generated at a second time;
determining, by the one or more processors of the device, a step width of the user based at least in part on a double integral of readings associated with acceleration along the z axis from the first time to the second time; and
providing, by the one or more processors of the device, data associated with the step width to a recipient device, wherein the recipient devices provides a perceivable indication associated with the data.
43 . The method of claim 42 further comprising determining a fundamental frequency using an autocorrelation function applied to the plurality of acceleration readings and in which the duration of the first window is a fraction of the fundamental frequency.
44 . The method of claim 42 further comprising only determining the step width in an instance in which none of the plurality of readings associated with acceleration along the z axis from the first time to the second time exceeds the threshold.
45 . The method of claim 42 further comprising multiplying the double integral of readings by a coefficient to determine the step width.
46 . The method of claim 45 , wherein the coefficient is proportional to the length of one or more of: an arm of the user; a leg of the user; a height of the user; or a measure of the user's body.
47 . The method of claim 42 further comprising:
comparing step widths of one or more even numbered steps to step widths of one or more odd numbered steps to determine a measure of symmetry; and
providing data associated with the measure of symmetry to the recipient device.
48 . The method of claim 42 further comprising:
determining a variability measure of a plurality of step widths; and
providing data associated with the variability measure to the recipient device.
49 . The method of claim 42 , wherein the recipient device comprises at least one of:
a non-transitory computer-readable medium;
a recipient device communicatively coupled, by a network, to the one or more processors;
an electromagnetic transmitter; or
a user interface.
50 . A computer program product for determining a step width of a user based at least in part on acceleration data comprising a plurality of acceleration readings, the computer program product comprising non-transitory computer-readable medium storing instructions for execution by a device that cause the device to at least:
receive the plurality of acceleration readings, wherein the plurality of acceleration readings is generated by an accelerometer measuring acceleration of the user's arm, wherein (a) the plurality of acceleration readings is associated with acceleration along each of two or more orthogonal axes, and (b) at least one of the two or more orthogonal axes is parallel to the mediolateral anatomical axis of the user and is a z axis;
identify a first time at which a first combined reading was generated, wherein the first combined reading (a) is a lowest local minimum reading during a first window, and (b) comprises readings of at least two of the two or more orthogonal axes generated at a first given time;
identify a second time at which a second combined reading was generated, wherein the second combined reading (a) is a first occurring reading to exceed a threshold after the first reading, and (b) comprises readings of at least two of the two or more orthogonal axes generated at a second given time;
determine a step width of the user based at least in part on a double integral of readings associated with acceleration along the z axis from the first time to the second time; and
provide data associated with the step width to a recipient device, wherein the recipient devices provides a perceivable indication associated with the data.
51 . The computer program product of claim 50 , wherein the instructions further cause the device to at least determine a fundamental frequency using an autocorrelation function applied to the plurality of acceleration readings and in which the duration of the first window is a fraction of the fundamental frequency.
52 . The computer program product of claim 50 , wherein the instructions further cause the device to at least only determine the step width in an instance in which none of the plurality of readings associated with acceleration along the z axis from the first time to the second time exceeds the threshold.
53 . The computer program product of claim 50 , wherein the instructions further cause the device to at least multiply the double integral of readings by a coefficient to determine the step width.
54 . The computer program product of claim 53 , wherein the coefficient is proportional to the length of one or more of: an arm of the user; a leg of the user; a height of the user; or a measure of the user's body.
55 . The computer program product of claim 50 , wherein the instructions further cause the device to at least:
compare step widths of one or more even numbered steps to step widths of one or more odd numbered steps to determine a measure of symmetry; and
provide data associated with the measure of symmetry to the recipient device.
56 . The computer program product of claim 50 , wherein the instructions further cause the device to at least:
determine a variability measure of a plurality of step widths; and
provide data associated with the variability measure to the recipient device.
57 . The computer program product of claim 50 , wherein the recipient device comprises at least one of:
a non-transitory computer-readable medium;
a recipient device communicatively coupled to the at least one processor using a network;
an electromagnetic transmitter; or
a user interface.