# US 11,908,145 B2 · Digital assessment of position of motion trackers on a person > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,908,145 B2 - Document ID: US11908145B2 - Status: Granted - Kind: B2 - Application number: 18/128,205 - Filed: 2023-03-29 - Published: 2023-09-07 - Granted: 2024-02-20 - Earliest claimed: 2021-03-30 - Assignees: Sword Health, S.A. - Applicants: Sword Health, S.A. - Inventors: José Carlos Coelho Alves; Márcio Filipe Moutinho Colunas; Pedro Henrique Oliveira Santos; Virgílio António Ferro Bento - Web page: https://patentgrep.com/patent/US11908145B2 ## CPC - G06F 3/011: {Arrangements for interaction with the human body, e.g. for user immersion in virtual reality (blind teaching G09B21/00)} - G06T 7/246: using feature-based methods, e.g. the tracking of corners or segments - A61B 5/112: {Gait analysis} - A61B 5/1121: {Determining geometric values, e.g. centre of rotation or angular range of movement} - A61B 5/1127: {using markers} - G06T 7/73: using feature-based methods - G06V 10/141: Control of illumination - G06V 10/245: {by locating a pattern; Special marks for positioning} - G06V 10/62: relating to a temporal dimension, e.g. time-based feature extraction; Pattern tracking - G06V 40/25: {Recognition of walking or running movements, e.g. gait recognition} - A61B 2034/2048: {using an accelerometer or inertia sensor} - A61B 2034/2065: {Tracking using image or pattern recognition} - A61B 2090/3945: {Active visible markers, e.g. light emitting diodes} - G06T 2207/10024: Color image - G06T 2207/20044: Skeletonization; Medial axis transform - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract A method for assessing whether one or more trackers are positioned on a person according to a predetermined configuration of tracker positions, comprising: transmitting, from a computing device to at least one tracker of the one or more trackers, an instruction to change an operation of the light emitter of the tracker to which the instruction is transmitted; taking one or more images by the optical sensing device; digitally processing the one or more images to digitally determine both first positions of a plurality of joints of the person on each image, and second positions of the one or more trackers positioned on the person on each image based on both a light of the light emitter of each of the one or more trackers and the transmitted instructions; digitally determining on which body member each of the one or more trackers is positioned on the person based on the first and second positions; and digitally comparing the position of each of the one or more trackers on the body members with the predetermined configuration of tracker positions. ## Claims ### Claim 1 A method for assessing a position of at least one tracker on a subject, the method comprising: (a) determining a target configuration of a position of the at least one tracker on the subject; (b) activating a light emitter of the at least one tracker and imaging the subject using an optical sensing device to acquire at least one image of the subject comprising an image of the at least one tracker; (c) automatically processing the at least one image by a computing device to determine a difference between an actual position of the at least one tracker and the determined target configuration of the position of the at least one tracker; and (d) providing an indication of the determined difference to a user of the computing device. ### Claim 2 (depends on 1) The method of claim 1, wherein the at least one tracker comprises a plurality of trackers. ### Claim 3 (depends on 2) The method of claim 2, wherein the indication of (d) comprises an alert that at least one tracker of the plurality of trackers is incorrectly positioned. ### Claim 4 (depends on 3) The method of claim 3, wherein the indication of (d) further comprises user guidance on how to reposition the at least one incorrectly positioned tracker. ### Claim 5 (depends on 4) The method of claim 4, wherein the guidance on how to reposition the at least one incorrectly positioned tracker is determined at least in part by comparing the distances between each of the trackers and the target configuration of (a), and comprises providing instructions to move a closest tracker to a specified tracker position of the target configuration. ### Claim 6 (depends on 3) The method of claim 3, wherein the light emitter of each of the plurality of trackers comprises a plurality of light emission modes corresponding to different emitted light wavelengths. ### Claim 7 (depends on 6) The method of claim 6, wherein the light emitter of each of the plurality of trackers emits light with a color different from a color of the light of the light emitters of other trackers of the plurality. ### Claim 8 (depends on 7) The method of claim 7, wherein determination of (c) is based at least in part on the color of the light of the light emitter of the tracker. ### Claim 9 (depends on 2) The method of claim 2, further comprising automatically determining an identity of the body member upon which each tracker of the plurality of trackers is positioned. ### Claim 10 (depends on 2) The method of claim 2, wherein each of the plurality of trackers comprises at least one antenna configured to transmit and/or receive a wireless signal, and at least one inertial sensor. ### Claim 11 (depends on 10) The method of claim 10, wherein the determining the difference of (c) comprises computing an angle between the at least one inertial sensor and a reference point on the body of the subject. ### Claim 12 (depends on 11) The method of claim 11, wherein the target configuration of (a) comprises a target rotational orientation of the tracker with respect to a reference point on the body of the subject. ### Claim 13 (depends on 1) The method of claim 1, wherein the activating of (b) comprises transmitting a wireless signal to the at least one tracker to trigger activation of the light emitter. ### Claim 14 (depends on 1) The method of claim 1, wherein the determined target configuration of (a) and the actual position of (c) comprise a position of the at least one tracker relative to a position of a readily determinable reference point of a body member of the subject. ### Claim 15 (depends on 1) The method of claim 1, further comprising repeatedly performing (b)-(d). ### Claim 16 (depends on 15) The method of claim 15, wherein (b)-(d) are repeated until the determined difference of (c) is less than a threshold value. ### Claim 17 (depends on 16) The method of claim 16, wherein when the determined difference of (c) is less than the threshold value, the indication of (d) comprises an indication that the one or more tracker is in the predetermined position. ### Claim 18 (depends on 17) The method of claim 17, wherein the target configuration of (a) comprises a target rotational orientation of the tracker with respect to a reference point on the body of the subject, and the determined difference of (c) comprises an angular difference between the orientation of the one or more trackers and the target rotational orientation. ### Claim 19 A positioning system for properly positioning at least one tracker on a body of a subject, the positioning system comprising: at least one tracker adapted to be arranged on the body of the subject, the at least one trackers comprising: a light emitter, at least one antenna configured to transmit and/or receive a wireless signal, and at least one inertial sensor; an optical sensing device; and a computing device comprising at least one antenna configured to transmit and/or receive a wireless signal, the computing device being configured to: (a) determine a target configuration of a position of the at least one tracker on the subject; (b) activate a light emitter of the at least one tracker and image the subject using the optical sensing device to acquire at least one image of the subject comprising an image of the at least one tracker; (c) automatically process the at least one image to determine a difference between an actual position of the at least one tracker and the determined target configuration of the position of the at least one tracker; and (d) provide an indication of the determined difference to a user of the positioning system. ### Claim 20 (depends on 19) The positioning system of claim 19, the at least one tracker comprises a plurality of trackers, each comprising at least one antenna configured to transmit and/or receive a wireless signal, and at least one inertial sensor.