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 double limb support time 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;
identify a first time at which a first reading of the plurality of acceleration readings was generated, wherein the first reading is a lowest local minimum reading during a first window;
identify a second time at which a second reading of the plurality of acceleration readings was generated, wherein the second reading is a first occurring reading to exceed a threshold after the first reading;
determine the double limb support time by determining a difference between the first time and the second time, wherein the double limb support time is indicative of at least a portion of a step in which the user's weight is at least partially supported on both limbs; and
provide data associated with the double limb support time to a recipient device, wherein the recipient device 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 a plurality of readings of the plurality of acceleration readings and in which a 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 compare double limb support times of one or more even numbered steps to double limb support times of one or more odd numbered steps to determine a measure of symmetry and provide the measure of symmetry to the recipient device.
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 determine a variability measure of a plurality of double limb support times and provide data associated with the variability measure to the recipient device.
38 . 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.
39 . The device of claim 38 , wherein (a) the recipient device comprises the user interface, and (b) the user interface comprises one or more of: a visual display, an audio speaker, or a tactile output.
40 . The device of claim 34 , wherein the at least one processor is powered by one or more of: a battery, a photovoltaic cell, a body heat ambient energy collector, or a body motion ambient energy collector.
41 . The device of claim 34 , wherein the time at which the first reading was generated and the time at which the second reading was generated are determined relative to one or more of: time cycles of the at least one processor, readings from the accelerometer, an electric clock, a quartz clock, or a radio-controlled clock that is wirelessly synchronized with an atomic clock.
42 . The device of claim 34 in which the at least one processor:
adds the double limb support time to a cumulative double limb support time; and
provides data associated with the cumulative double limb support time to the recipient device.
43 . A method for determining a double limb support time 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;
identifying, by the one or more processors of the device, a first time at which a first reading of the plurality of acceleration readings was generated, wherein the first reading is a lowest local minimum reading during a first window;
identifying, by the one or more processors of the device, a second time at which a second reading of the plurality of acceleration readings was generated, wherein the second reading is a first occurring reading to exceed a threshold after the first reading;
determining, by the one or more processors of the device, the double limb support time by determining a difference between the first time and the second time, wherein the double limb support time is indicative of at least a portion of a step in which the user's weight is at least partially supported on both limbs; and
providing, by the one or more processors of the device, data associated with the double limb support time to a recipient device, wherein the recipient device provides a perceivable indication associated with the data.
44 . The method of claim 43 further comprising:
determining a fundamental frequency using an autocorrelation function applied to a plurality of readings of the plurality of acceleration readings; and
setting a duration of the first window as a fraction of the fundamental frequency.
45 . The method of claim 43 further comprising:
comparing double limb support times of one or more even numbered steps to double limb support times of one or more odd numbered steps to determine a measure of symmetry; and
providing the measure of symmetry from the one or more processors to the recipient device.
46 . The method of claim 43 further comprising:
determining a variability measure of a plurality of double limb support times; and
providing data associated with the variability measure from the one or more processors to the recipient device.
47 . The method of claim 43 , 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.
48 . The method of claim 47 , wherein (a) the recipient device comprises the user interface, and (b) the user interface comprises one or more of: a visual display, an audio speaker, or a tactile output.
49 . The method of claim 43 , wherein the one or more processors are powered by one or more of: a battery, a photovoltaic cell, a body heat ambient energy collector, or a body motion ambient energy collector.
50 . The method of claim 43 , wherein the time at which the first reading was generated and the time at which the second reading was generated are determined relative to one or more of: time cycles of the one or more processors, readings from the accelerometer, an electric clock, a quartz clock, or a radio-controlled clock that is wirelessly synchronized with an atomic clock.
51 . The method of claim 43 further comprising:
adding the double limb support time to a cumulative double limb support time; and
providing data associated with the cumulative double limb support time to the recipient device.
52 . A computer program product for determining a double limb support time 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;
identify a first time at which a first reading of the plurality of acceleration readings was generated, wherein the first reading is a lowest local minimum reading during a first window;
identify a second time at which a second reading of the plurality of acceleration readings was generated, wherein the second reading is a first occurring reading to exceed a threshold after the first reading;
determine the double limb support time by determining a difference between the first time and the second time, wherein the double limb support time is indicative of at least a portion of a step in which the user's weight is at least partially supported on both limbs; and
provide data associated with the double limb support time to a recipient device, wherein the recipient device provides a perceivable indication associated with the data.
53 . The computer program product of claim 52 , wherein the instructions further cause the device to at least determine a fundamental frequency using an autocorrelation function applied to a plurality of readings of the plurality of acceleration readings and in which a duration of the first window is a fraction of the fundamental frequency.
54 . The computer program product of claim 52 , wherein the instructions further cause the device to at least compare double limb support times of one or more even numbered steps to double limb support times of one or more odd numbered steps to determine a measure of symmetry and provide the measure of symmetry to the recipient device.
55 . The computer program product of claim 52 , wherein the instructions further cause the device to at least determine a variability measure of a plurality of double limb support times and provide data associated with the variability measure to the recipient device.
56 . The computer program product of claim 52 , 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.
57 . The computer program product of claim 56 , wherein (a) the recipient device comprises the user interface, and (b) the user interface comprises one or more of: a visual display, an audio speaker, or a tactile output.
58 . The computer program product of claim 52 , wherein a component of the device powered by one or more of: a battery, a photovoltaic cell, a body heat ambient energy collector, or a body motion ambient energy collector.
59 . The computer program product of claim 52 , wherein the time at which the first reading was generated and the time at which the second reading was generated are determined relative to one or more of: time cycles of the at least one processor, readings from the accelerometer, an electric clock, a quartz clock, or a radio-controlled clock that is wirelessly synchronized with an atomic clock.
60 . The computer program product of claim 52 , wherein the device:
adds the double limb support time to a cumulative double limb support time; and
provides data associated with the cumulative double limb support time to the recipient device.