# US 11,307,050 B2 · Measuring method and device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,307,050 B2 - Document ID: US11307050B2 - Status: Granted - Kind: B2 - Application number: 16/900,618 - Filed: 2020-06-12 - Published: 2021-12-16 - Granted: 2022-04-19 - Earliest claimed: 2020-06-12 - Assignees: Koneksa Health Inc. - Applicants: Koneksa Health Inc. - Inventors: Peter John Kelly; Robert David Ellis; Chengrui Huang - Web page: https://patentgrep.com/patent/US11307050B2 ## CPC - G01C 21/14: by recording the course traversed by the object (G01C21/16 takes precedence) - G01C 22/006: {Pedometers} - A61B 5/1112: {Global tracking of patients, e.g. by using GPS} - A61B 5/112: {Gait analysis} - A61B 5/1123: {Discriminating type of movement, e.g. walking or running (A61B5/1116, A61B5/112 take precedence)} - G01P 15/18: in two or more dimensions - A61B 5/6898: {Portable consumer electronic devices, e.g. music players, telephones, tablet computers} - G01C 21/206: {specially adapted for indoor navigation} - G06F 2218/20: by applying autoregressive analysis - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An apparatus and method determine movement information for a user that carries an accelerometer whilst moving. The apparatus receives acceleration data from the accelerometer defined relative to a frame of reference of the accelerometer. A transformation is determined and applied to the acceleration data or to data derived from the acceleration data to determine acceleration data is a user frame of reference that includes a user direction of travel and a side to side direction transverse to the user direction of travel. The acceleration data or data derived from the acceleration data is analyzed to determine a time period corresponding either to a user stride period or to a step period as the user is walking or running; and information about accelerations in the side to side direction are used to disambiguate whether the determined time period corresponds to the user stride period or to the user step period. ## Claims ### Claim 1 An apparatus for determining movement information for a user that carries an accelerometer whilst moving, the apparatus comprising one or more processors and memory configured to: receive acceleration data from the accelerometer, the acceleration data defining accelerations experienced by the accelerometer resulting from movement of the user, the accelerations being defined relative to a frame of reference associated with the accelerometer; process the acceleration data or data derived from the acceleration data, including: applying a transformation for transforming the frame of reference to a frame of reference of the user that includes a direction of travel of the user and a side to side direction transverse to the direction of travel of the user to provide transformed data or transformed data; processing the transformed data to determine information about accelerations in said side to side direction; determining a time period corresponding to a maximum peak in an autocorrelation function or a frequency function, wherein the determined time period is ambiguous and corresponds either to a stride period or to a step period of the user; and use said information about accelerations in said side to side direction to disambiguate whether the determined time period corresponds to the stride period of the user or to the step period of the user. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the processor and memory are configured to use information about accelerations in said side to side direction and in said direction of travel to disambiguate whether the determined time period corresponds to the stride period of the user or to the step period of the user. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein the processor and memory are configured to determine a first autocorrelation function to determine said time period corresponding either to said stride period or to said step period of the user. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the processor and memory are configured to process the first autocorrelation function to identify a peak in the first autocorrelation function at an autocorrelation lag corresponding to the stride period of the user or to the step period of the user. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the processor and memory are configured to process the first autocorrelation function to identify the highest peak in the first autocorrelation function after a zero lag peak and to determine the time period corresponding to the stride period of the user or to the step period of the user as the autocorrelation lag associated with the identified highest peak. ### Claim 6 (depends on 4) The apparatus according to claim 4, wherein said processor and memory are configured to determine a second autocorrelation function of the accelerations in said side to side direction and are configured to disambiguate whether the time period corresponds to the stride period or the step period in dependence upon whether or not the second autocorrelation function includes a peak around the autocorrelation lag corresponding to the step or stride period. ### Claim 7 (depends on 4) The apparatus according to claim 4, wherein said processor and memory are configured to determine a second autocorrelation function of the accelerations in said side to side direction and a third autocorrelation function of the accelerations in said direction of travel and are configured to disambiguate whether the time period corresponds to the stride period or the step period in dependence upon whether or not the second autocorrelation function includes a peak around the autocorrelation lag corresponding to the step or stride period. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein the processor and memory are configured to use the first, second and third autocorrelation functions to confirm that the user is walking or running or not walking or not running. ### Claim 9 (depends on 3) The apparatus according to claim 3, wherein said first autocorrelation function is calculated on said accelerometer data or on data derived from said accelerometer data. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the processor and memory are configured to determine and apply a first transformation that aligns a first axis of the accelerometer data or data derived from the accelerometer data with a vertical axis. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the processor and memory are configured to determine and apply a second transformation that aligns a second axis of the accelerometer data or data derived from the accelerometer data with said direction of travel and a third axis of the accelerometer data or data derived from the accelerometer data with said side to side direction. ### Claim 12 (depends on 1) The apparatus according to claim 1, wherein the processor and memory are configured to: process the transformed data to determine information about accelerations in said direction of travel; determine that the determined time period corresponds to a stride period of the user when the information about accelerations in the side to side direction matches information about accelerations in the direction of travel; and determine that the determined time period corresponds to a step period of the user when the information about accelerations in the side to side direction does not match the information about accelerations in the direction of travel. ### Claim 13 (depends on 1) The apparatus of claim 1, wherein the frame of reference of the user comprises a vertical direction transverse to both the direction of travel and the side to side direction. ### Claim 14 (depends on 1) The apparatus according to claim 1, wherein the processor and memory are configured to process the acceleration data to identify periods of walking or running within the acceleration data and is configured to determine said time period corresponding either to a stride period or to a step period of the user using acceleration data from within an identified period of walking or running. ### Claim 15 (depends on 1) The apparatus according to claim 1, wherein the processor and memory are configured to determine the direction of travel and the side to side direction as orthogonal directions in a horizontal plane that have the most and the least variability in the received acceleration data such that the direction with most variability in the acceleration data corresponds to the forwards/backwards direction and the direction with least variability in the acceleration data corresponds to the side to side direction. ### Claim 16 (depends on 1) The apparatus according to claim 1, wherein the processor and memory are further configured to use the disambiguated step period or stride period to determine a step count of the user for movements corresponding to walking or running. ### Claim 17 (depends on 1) The apparatus according to claim 1, wherein the apparatus forms part of a user device carried by the user and wherein the accelerometer forms part of the user device or is configured to communicate with the user device. ### Claim 18 (depends on 1) An apparatus according to claim 1 forming part of a clinical trial system comprising a central computer that communicates with a plurality of user devices, each user device being arranged to collect acceleration data relating to movement of the user associated with the user device; and wherein the central computer or at least one user device comprises the apparatus according to claim 1 for analyzing acceleration data. ### Claim 19 (depends on 1) The apparatus according to claim 1, wherein the one or more processors and memory are configured to apply the transformation to the acceleration data. ### Claim 20 (depends on 1) The apparatus according to claim 1, wherein the one or more processors and memory are configured to apply the transformation to data derived from the acceleration data. ### Claim 21 (depends on 20) The apparatus according to claim 20, wherein the data derived from the acceleration data comprises autocorrelation data obtained by determining an autocorrelation function of the acceleration data. ### Claim 22 (depends on 1) The apparatus according to claim 1, wherein the autocorrelation function or the frequency function is determined on the acceleration data. ### Claim 23 (depends on 1) The apparatus according to claim 1, wherein the autocorrelation function or the frequency function is determined on the transformed data. ### Claim 24 An apparatus for determining movement information for a user that carries an accelerometer whilst moving, the apparatus comprising one or more processors and memory configured to: receive acceleration data from the accelerometer, the acceleration data defining accelerations experienced by the accelerometer resulting from movement of the user, the accelerations being defined relative to a frame of reference associated with the accelerometer; apply a transformation for transforming the frame of reference to a frame of reference of the user that includes a purported direction of travel of the user and a side to side direction transverse to the purported direction of travel of the user to provide transformed acceleration data or transformed data derived from the acceleration data that includes i) acceleration data for accelerations in said purported direction of travel, and ii) acceleration data for accelerations in said side to side direction; determine a first autocorrelation function of the acceleration data or of the transformed acceleration data; determine a second autocorrelation function of said acceleration data for accelerations in said purported direction of travel that is included in said transformed acceleration data; determine a third autocorrelation function of said acceleration data for accelerations in said side to side direction that is included in said transformed acceleration; and determine if the user is walking or not walking or running or not running using the first, second and third autocorrelation functions. ### Claim 25 A method for determining movement information for a user that carries an accelerometer whilst moving, the method comprising: receiving acceleration data from the accelerometer, the acceleration data defining accelerations experienced by the accelerometer resulting from movement of the user, the accelerations being defined relative to a frame of reference associated with the accelerometer; processing the acceleration data, including: applying a transformation for transforming the frame of reference to a frame of reference of the user that includes a direction of travel of the user and a side to side direction transverse to the direction of travel of the user to provide transformed data; processing the transformed data or the transformed data to determine information about accelerations in said side to side direction; determining an autocorrelation function or a frequency function; and determining a time period corresponding to a maximum peak in the autocorrelation function or the frequency function, wherein the determined time period is ambiguous and corresponds either to a stride period or to a step period of the user as the user is walking or running; and using said information about accelerations in said side to side direction to disambiguate whether the determined time period corresponds to the stride period of the user or to the step period of the user. ### Claim 26 (depends on 25) The method according to claim 25, wherein the transformation is applied to the acceleration data. ### Claim 27 (depends on 25) The method according to claim 25, wherein the transformation is applied to data derived from the acceleration data. ### Claim 28 (depends on 27) The method according to claim 27, wherein the data derived from the acceleration data comprises autocorrelation data obtained by determining an autocorrelation function of the acceleration data. ### Claim 29 (depends on 25) The method according to claim 25, wherein the autocorrelation function or the frequency function is determined on the acceleration data. ### Claim 30 (depends on 25) The method according to claim 25, wherein the autocorrelation function or the frequency function is determined on the transformed data. ### Claim 31 A method for determining movement information for a user that carries an accelerometer whilst moving, the method comprising: receiving acceleration data from the accelerometer, the acceleration data defining accelerations experienced by the accelerometer resulting from movement of the user, the accelerations being defined relative to a frame of reference associated with the accelerometer; applying a transformation for transforming the frame of reference to a frame of reference of the user that includes a purported direction of travel of the user and a side to side direction transverse to the purported direction of travel of the user to provide transformed acceleration data that includes i) acceleration data for accelerations in said purported direction of travel, and ii) acceleration data for accelerations in said side to side direction; determining a first autocorrelation function of the acceleration data or of the transformed acceleration data; determining a second autocorrelation function of said acceleration data for accelerations in said purported direction of travel that is included in said transformed acceleration data; determining a third autocorrelation function of said acceleration data for accelerations in said side to side direction that is included in said transformed acceleration data; and determining if the user is walking or not walking or running or not running using the first, second and third autocorrelation functions.