# US 2021/0274888 A1 · Foot presence sensing using magnets in footwear > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0274888 A1 - Document ID: US20210274888A1 - Status: Published application - Kind: A1 - Application number: 17/329,422 - Filed: 2021-05-25 - Published: 2021-09-09 - Earliest claimed: 2016-03-15 - Assignees: NIKE, Inc. - Applicants: NIKE, Inc. - Inventors: Steven H. Walker; Phillip Meneau - Web page: https://patentgrep.com/patent/US20210274888A1 ## CPC - A43C 11/165: {characterised by a spool, reel or pulley for winding up cables, laces or straps by rotation} - A43B 1/0054: {provided with magnets, magnetic parts or magnetic substances} - A43B 3/0031: {provided with a pocket, e.g. for keys or a card} - A43B 3/36: with light sources - A43B 3/44: with sensors, e.g. for detecting contact or position - A43B 13/125: {characterised by the midsole or middle layer} - A43B 13/14: characterised by the constructive form - A43B 13/18: Resilient soles {(skating boots provided with resilient means A43B5/1658)} - A43B 17/00: Insoles for insertion, e.g. footbeds or inlays, for attachment to the shoe after the upper has been joined - A43C 1/00: Shoe lacing fastenings (garment fastening devices A41F) - A43C 7/00: Holding-devices for laces - A43C 7/08: Clamps drawn tight by laces - A43C 11/008: {Combined fastenings, e.g. to accelerate undoing or fastening} - A43C 11/14: Clamp fastenings {, e.g. strap fastenings}; Clamp-buckle fastenings; Fastenings with toggle levers - A61B 5/1036: {Measuring load distribution, e.g. podologic studies} - A61B 5/6807: {Footwear} - G01D 5/12: using electric or magnetic means (G01D5/06 takes precedence) - G01D 5/24: by varying capacitance - G01L 1/12: by measuring variations in the magnetic properties of materials resulting from the application of stress - G01L 1/14: by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators - G01L 1/142: {using capacitors} - G01L 1/144: {with associated circuitry (G01L1/146 and G01L1/148 take precedence)} - G01L 5/0009: {Force sensors associated with a bearing (testing of bearings G01M13/04)} - G01L 5/0014: {by using capacitive sensors} - G01L 5/0071: {Specific indicating arrangements, e.g. of overload} - G01L 5/12: for measuring axial thrust in a rotary shaft, e.g. of propulsion plants - G01L 5/16: for measuring several components of force - G01L 5/165: using variations in capacitance - G01L 5/24: for determining value of torque or twisting moment for tightening a nut or other member which is similarly stressed - G05B 15/02: electric - G05B 19/048: Monitoring; Safety - A43B 3/38: with power sources - A43C 1/003: {Zone lacing, i.e. whereby different zones of the footwear have different lacing tightening degrees, using one or a plurality of laces (laces combined with another system A43C11/008; zone tightening using straps A43C11/14)} - A43C 1/006: {Rear lacing, i.e. with a lace placed on the back of the foot in place of, or in addition to the traditional front lace} - A43C 1/02: with elastic laces - A43C 1/04: with rings or loops - A43C 1/06: tightened by draw-strings - A43C 11/00: Other fastenings specially adapted for shoes (dress fastenings in general A44B) - G01D 5/145: {influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06)} - G01D 5/2405: {by varying dielectric} - G01D 5/34: the beams of light being detected by photocells - G05B 2219/24015: Monitoring - Y02P 90/02: Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS] - A43C: FASTENINGS OR ATTACHMENTS OF FOOTWEAR; LACES IN GENERAL - A43B: CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract An article of footwear can include a ferromagnetic body disposed in the article, and a magnetometer to measure a strength or direction of a magnetic field that is influenced by a position of the ferromagnetic body. One of the ferromagnetic body and the magnetometer can be configured to move relative to the other one of the ferromagnetic body and the magnetometer, for example according to movement of a foot in the article. In an example, the ferromagnetic body is disposed in a compressible insole and the ferromagnetic body moves in response to compression or relaxation of the insole. The magnetometer can be disposed in a platform or sole portion of the article that is relatively stationary compared to the ferromagnetic body. Rate of change information about the magnetic field can be used to control article functions or to provide information about a foot strike or step rate. ## Claims ### Claim 1 An article of footwear comprising: a ferromagnetic body disposed in the article of footwear; a magnetometer configured to provide a magnetometer signal that indicates a strength or direction of a magnetic field measured by the magnetometer, wherein the magnetometer signal indicates a position of the ferromagnetic body; and a processor circuit configured to receive the magnetometer signal from the magnetometer and determine a foot impact characteristic using the magnetometer signal; wherein one of the ferromagnetic body and the magnetometer is configured to move relative to the other one of the ferromagnetic body and the magnetometer according to movement of a foot in the article. ### Claim 2 (depends on 1) The article of footwear of claim 1, wherein in response to the magnetometer signal indicating a specified change in the position of the ferromagnetic body, the processor circuit is configured to initiate data collection from one or more other sensors in or associated with the article of footwear. ### Claim 3 (depends on 1) The article of footwear of claim 1, wherein in response to the magnetometer signal indicating a specified change in the position of the ferromagnetic body, the processor circuit is configured to actuate a drive mechanism to tighten or loosen the article of footwear about the foot. ### Claim 4 (depends on 3) The article of footwear of claim 3, further comprising the drive mechanism, wherein the drive mechanism is configured to tighten or loosen the article of footwear about the foot in response to actuation instructions from the processor circuit. ### Claim 5 (depends on 1) The article of footwear of claim 1, wherein the magnetometer signal comprises a time-varying signal that indicates a changing position of the ferromagnetic body while the article is worn and while the article is moved by a foot; and the processor circuit is configured to determine the foot impact characteristic based on a rate of change of the time-varying signal. ### Claim 6 (depends on 5) The article of footwear of claim 5, wherein the processor circuit is configured to determine a foot impact force characteristic based on the time-varying signal. ### Claim 7 (depends on 5) The article of footwear of claim 5, wherein the processor circuit is configured to determine a step timing characteristic based on the time-varying signal. ### Claim 8 (depends on 5) The article of footwear of claim 5, wherein the processor circuit is configured to determine a step count using the foot impact characteristic as-determined. ### Claim 9 (depends on 1) The article of footwear of claim 1, further comprising multiple ferromagnetic bodies disposed in the article of footwear, wherein the magnetometer signal indicates a change in a position of one or more of the multiple ferromagnetic bodies, and wherein the multiple ferromagnetic bodies are spaced apart from each other and from the magnetometer. ### Claim 10 (depends on 1) The article of footwear of claim 1, wherein the ferromagnetic body is embedded in a compressible material that is configured to be worn underfoot in the article of footwear. ### Claim 11 A method comprising: using a magnetometer, measuring a strength or direction of a magnetic field generated by a ferromagnetic body that is disposed in an article of footwear; and using a processor circuit: receiving a signal from the magnetometer indicating the strength or direction of the magnetic field as-measured; and determining a foot impact characteristic, corresponding to movement of a foot inside of the article of footwear, using the signal. ### Claim 12 (depends on 11) The method of claim 11, wherein receiving the signal from the magnetometer includes receiving a time-varying signal from the magnetometer, the time-varying signal indicating a change in the strength or direction of the magnetic field over time. ### Claim 13 (depends on 12) The method of claim 12, further comprising determining a rate of change of the time-varying signal as-received; wherein determining the foot impact characteristic includes using the rate of change as-determined. ### Claim 14 (depends on 13) The method of claim 13, further comprising using the processor circuit, determining a foot impact force characteristic using the rate of change as-determined. ### Claim 15 (depends on 13) The method of claim 13, further comprising using the processor circuit, determining a step timing characteristic using the rate of change as-determined. ### Claim 16 (depends on 13) The method of claim 13, further comprising using the processor circuit, determining a step count using the rate of change as-determined. ### Claim 17 (depends on 13) The method of claim 13, further comprising using the processor circuit, determining a gait characteristic using the rate of change as-determined. ### Claim 18 (depends on 13) The method of claim 13, further comprising using the processor circuit, selectively actuating a lace drive mechanism based on the rate of change as-determined. ### Claim 19 An article of footwear comprising: a ferromagnetic body disposed in the article of footwear; a magnetometer configured to provide a magnetometer signal that indicates a strength or direction of a magnetic field measured by the magnetometer, wherein the magnetometer signal indicates a position of the ferromagnetic body; an automatic lacing engine; and a processor circuit configured to receive the magnetometer signal from the magnetometer, determine a rate of change of the magnetometer signal over time, and selectively actuate the automatic lacing engine to tighten or relax the article of footwear about a foot based on the rate of change as-determined; wherein one of the ferromagnetic body and the magnetometer is configured to move relative to the other one of the ferromagnetic body and the magnetometer according to movement of the foot in the article. ### Claim 20 (depends on 19) The article of footwear of claim 19, wherein the processor circuit is further configured to classify an activity type based on the rate of change as-determined, and wherein the processor circuit is configured to actuate the automatic lacing engine based on the activity type.