FOOT-MOUNTED SENSOR SYSTEMS FOR TRACKING BODY MOVEMENT

• US 20150359457A1
• Filed: 06/17/2015
• Published: 12/17/2015
• Est. Priority Date: 12/17/2012
• Status: Active Grant

• Current Assignee: Reflx Labs, Inc.
• Original Assignee: Reflx Labs, Inc.
• Inventors: Blumenthal, Tyler, Bondurant, Phillip Dewayne, Fratello, Vincent, Lentz, Christian Robert, Nino, Giovanni, Torres, Jose Jr.
• Granted Patent: US 10,307,081 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A42B 3/046 Means for detecting hazards or accidents
• CPC Class Codes: A43B 3/34 with electrical or electronic arrangements
• CPC Class Codes: A43B 3/44 with sensors, e.g. for detecting contact or position
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/0271 Thermal or temperature sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/02444 Details of sensor A61B5/02427 takes precedence
• CPC Class Codes: A61B 5/103 Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes A61B5/08 takes precedence; measuring aids for tailors A41H1/00; measuring instruments specially adapted for dentistry A61C19/04
• CPC Class Codes: A61B 5/1038 Measuring plantar pressure during gait
• CPC Class Codes: A61B 5/1112 Global tracking of patients, e.g. by using GPS
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/1123 Discriminating type of movement, e.g. walking or running A61B5/1116, A61B5/112 take precedence
• CPC Class Codes: A61B 5/6803 Head-worn items, e.g. helmets, masks, headphones or goggles
• CPC Class Codes: A61B 5/6807 Footwear
• CPC Class Codes: A61B 5/6895 Sport equipment
• CPC Class Codes: A61B 5/6898 Portable consumer electronic devices, e.g. music players, telephones, tablet computers
• CPC Class Codes: A63C 2203/18 Measuring a physical parameter, e.g. speed, distance
• CPC Class Codes: A63C 2203/24 : Processing or storing data, e.g. with electronic chip
• CPC Class Codes: A63F 13/212 : using sensors worn by the player, e.g. for measuring heart beat or leg activity
• CPC Class Codes: A63F 13/218 : using pressure sensors, e.g. generating a signal proportional to the pressure applied by the player
• CPC Class Codes: A63F 13/50 : Controlling the output signals based on the game progress
• CPC Class Codes: A63F 2300/1012 : involving biosensors worn by the player, e.g. for measuring heart beat, limb activity
• CPC Class Codes: G01G 19/44 : for weighing persons
• CPC Class Codes: G06F 3/011 : Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/0334 : Foot operated pointing devices

Abstract

A method is disclosed for foot sensors to be used to determine at least two characteristics of a subject'"'"'s activity by using a combination of sensors for force and foot orientation/motion/position. A wearable footwear ecosystem is comprised of the subject'"'"'s footwear, sensor-enabled insoles or insertable devices, in- or on-footwear electronics that is hard wired to the sensors and may contain additional sensors such as accelerometers, a master device and means to communicate (typically wirelessly) among the various sensor platforms, and the master device including clock synchronization. Correlating the time stamps for data among various sensors, and the master device communicating wirelessly is critical to accurate determination of the desired characteristics. Multiple force-sensitive resistors on a common substrate are individually optimized for dynamic range. Pulse sensors using arrays of such force-sensitive resistors are implemented. The resultant system can profitably be used for gaming, biometric monitoring, and activity tracking.

Claims

1. A method of determining two or more characteristics of an activity performed by a subject, comprising:

(a) providing a sensor system, comprising;

two separate foot sensor subsystems, each comprising

two or more force sensitive resistors configured to measure a force at two or more predetermined anatomical locations on a foot,

at least one sensor device selected from the group consisting of an accelerometer and a gyroscope, and

a clock configured to generate time stamped device data for each sensor device that includes a relative time that the device data was generated, wherein each clock is synchronized by communication with a master device,

wherein each of the foot sensor subsystems is configured to be coupled to a separate foot of the subject; and

a data processor system in communication with both of the foot sensor subsystems and located separate from at least one of the foot sensor subsystems;

(b) generating time stamped activity data during the activity for each foot sensor subsystem based on the time stamped device data output;

(c) communicating the time stamped activity data for each foot sensor subsystem to the data processor system;

(d) correlating the time stamped activity data from each foot sensor subsystem to provide correlated activity data using the data processor system; and

(e) using the correlated activity data using the data processor system to determine two or more characteristics of the activity of the subject selected from the group consisting of balance, weight distribution across a foot, total weight applied to the foot, partial weight applied to the foot, foot movement, foot rotation, foot orientation, distance traveled, foot elevation, foot temperature, localized pressure on the foot, foot acceleration, foot speed, and dynamic load motion during foot movement.

2. The method of claim 1, wherein the sensor system is configured to be used outdoors.

3. The method of claim 1, wherein the sensor system is configured to be used indoors.

4. The method of claim 1, wherein the data processing system is interfaced with one or more of the following:

a display device;

an electronic game, the electronic game including one or more of a console game, a computer game, or a mobile game;

a speaker, earbuds, headphones, or sound generation device to provide aural feedback to the subject;

a workforce monitoring system for load on movement assessment;

a biomechanical analysis system; and

additional time correlated sensors at body locations other than the feet.

5. The method of claim 1, further comprising converting the two or more determined characteristics using a computing device to at least one of an output signal for moving an avatar in a virtual world or an output signal corresponding to a keyboard output signal.

6. The method of claim 1, wherein the sensor system further comprises one or more additional sensors selected from the group consisting of a global positioning system, an accelerometer, a gyroscope, an inertial navigation unit, a force sensor, a shear sensor, a pressure sensor, arrays of pressure sensors, a temperature sensor, a pulse sensor, and a blood pressure sensor.

7. The method of claim 1, wherein, in a reduced interconnect configuration, at least one of the sensor subsystems comprises a plurality of digital switches configured for pressure detection positioned adjacent to the bottom of the foot of the subject, wherein the at least one sensor subsystem includes a binary weighted ladder digital to analog (D-A) conversion circuit.

8. The method of claim 7, wherein the at least one sensor subsystem is configured to require an application of a force corresponding to the weight of the subject to activate the plurality of switches.

9. A force sensitive substrate comprising a first force sensitive resistive (FSR) device having a first dynamic range and a second FSR device having a second dynamic range, wherein the first FSR device and the second FSR device each have at least one of two FSR configurations:

in a shunt mode FSR configuration, the FSR includes a semiconducting material layer backed by a substrate, at least one spacer layer comprising a central hole, and a second layer comprising electrodes in an interdigitated pattern that drives a contact area between the two layers; and

in a thru mode FSR configuration, the FSR device includes two substrates each printed with a solid conductive pad and overprinted with a semiconducting material, wherein the two substrates are positioned to face one another, and wherein the two substrates are separated by a spacer layer comprising a central hole.

10. The force-sensitive substrate of claim 9, wherein one of the first FSR device and the second FSR device is configured to measure both an applied force and a position at a location, wherein the FSR device further comprises at least one of:

a linear potentiometer FSR configured to measure a position of the location with respect to one axis of translation and measure a force at the location;

an XYZ digitizer FSR array configured to measure a position of the location with respect to two axes of translation and measure a force at the location; and

an FSR matrix array configured to measure a position of the location with respect to three axes of translation and measure an applied force.

11. The force sensitive substrate of claim 9, wherein the first FSR device and the second FSR device of the force sensitive substrate are hermetically sealed within a body of the force sensitive substrate, and wherein the force sensitive substrate is configured to maintain the first FSR device and the second FSR device hermetically sealed within the force sensitive substrate when the force sensitive substrate changes shape.

12. The force sensitive substrate of claim 9, wherein at least one of the first dynamic range of the first FSR device and the second dynamic range of the second FSR device is optimized such that the difference between a minimum and a maximum output voltage of the at least one of the first dynamic range of the first FSR device and the second dynamic range of the second FSR device is about a factor of two.

13. The force sensitive substrate of claim 9, wherein the first dynamic range of the first FSR device or the second dynamic range of the second FSR device is modified by modifying at least one of the following characteristics of the FSR device:

(a) a spacer thickness of an FSR;

(b) a diameter of a central hole in a spacer layer of an FSR;

(c) a spacer Durometer hardness;

(d) a spacing between interdigitated conducting fingers of an FSR;

(e) a width of the interdigitated conducting fingers of an FSR;

(f) a thickness of the resistive layer;

(g) a thickness of a conducting finger substrate material;

(h) a Durometer hardness of a resistive layer or a Durometer hardness of a conducting finger substrate material;

(i) a sheet resistance of a resistive layer;

(j) an amount of dielectric dots; and

(k) a bias provided to an FSR to change a sensitivity of the FSR dynamically when using a transimpedance amplifier.

14. The force-sensitive substrate of claim 9, wherein the first FSR device is configured to measure a force at a first predetermined anatomical location on a foot and the second FSR device is configured to measure a force at a second predetermined anatomical location on the foot.

15. The force sensitive substrate of claim 9, further comprising a third FSR device, wherein the first FSR device is configured to measure a force at the head of the first metatarsal, the second FSR device is configured to measure a force at the base of the fifth metatarsal, and the third FSR device is configured to measure a force at approximately the calcaneus.

16. The force sensitive substrate of claim 9, wherein first FSR device and second FSR device are fabricated simultaneously in parallel and assembled as a single unit and the force sensitive substrate is sized and configured to match a shoe sole, an insole, or a pattern of anatomical locations, and wherein the first FSR device and second FSR device are inserted in a shoe, adhered or embedded in an insole, or adhered or embedded to the sole of the shoe.

17. The force-sensitive substrate of claim 9, wherein the FSR device is printed on the sole of the shoe, on an insole, or inside the shoe.

18. The force sensitive substrate of claim 9, wherein the force-sensitive substrate is adhered, printed, or embedded in a piece of athletic equipment comprising one or more of the following:

a helmet, a piece of padding, a ball, a bat, a golf club, a bicycle seat, a snow board, or a skateboard.

19. A system for determining two or more characteristics of an activity performed by a subject, the system comprising:

(a) two separate foot sensor subsystems, wherein each of the foot sensor subsystems is positioned adjacent to a separate foot of the subject, and wherein each foot sensor subsystem comprises two or more sensor devices selected from the group consisting of a force sensor, an accelerometer, and a gyroscope, wherein each foot sensor subsystem is configured to output time-stamped measurement data, wherein the outputted time-stamped measurement data includes the relative time that the measurement data was measured; and

(b) a processing system separately located from at least one of the foot sensor subsystems;

wherein the two separate foot sensor subsystems and the processing system are configured to be in data communication with one another; and

wherein the processing system is further configured to;

receive time-stamped activity data for each foot sensor subsystem;

correlate the time-stamped activity data for each foot sensor subsystem to provide correlated activity data; and

determine two or more characteristics of the activity of the subject using the correlated activity data.