Method and apparatus for estimating a motion parameter

• US 8,036,850 B2
• Filed: 11/14/2008
• Issued: 10/11/2011
• Est. Priority Date: 03/03/2006
• Status: Active Grant

• Current Assignee: Garmin Switzerland GmbH (Garmin Limited)
• Original Assignee: Garmin Switzerland GmbH (Garmin Limited)
• Inventors: MacDonald, Paul R., Rooney, James K., Kulach, Christopher J.
• Primary Examiner(s): Kundu; Sujoy
• Application Number:
  US12/271,512
• Publication Number:
  US 20090076765A1
• Time in Patent Office: 1,061 Days
• Field of Search: 702/141, 702/160, 702/176, 702/180, 364/410, 364/561, 364/564, 734/90, 735/140.1
• US Class Current: 702/141
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/1112 Global tracking of patients, e.g. by using GPS
• CPC Class Codes: A61B 5/112 Gait analysis
• 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 5/6807 Footwear
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A63B 2071/068 Input by voice recognition
• CPC Class Codes: A63B 2102/32 Golf
• CPC Class Codes: A63B 2220/12 Absolute positions, e.g. by using GPS
• CPC Class Codes: A63B 2220/18 Inclination, slope or curvature
• CPC Class Codes: A63B 2220/20 Distances or displacements
• CPC Class Codes: A63B 2220/30 Speed
• CPC Class Codes: A63B 2220/34 Angular speed
• CPC Class Codes: A63B 2220/40 Acceleration
• CPC Class Codes: A63B 2220/70 Measuring or simulating ambient conditions, e.g. weather, terrain or surface conditions
• CPC Class Codes: A63B 2220/72 Temperature
• CPC Class Codes: A63B 2220/836 Sensors arranged on the body of the user
• CPC Class Codes: A63B 2225/20 with means for remote communication, e.g. internet or the like
• CPC Class Codes: A63B 2225/50 Wireless data transmission, e.g. by radio transmitters or telemetry
• CPC Class Codes: A63B 2230/06 : heartbeat rate only
• CPC Class Codes: A63B 2230/75 : calorie expenditure
• CPC Class Codes: A63B 2243/0025 : Football American football A63B2243/007
• CPC Class Codes: A63B 2243/0037 : Basketball
• CPC Class Codes: A63B 24/0062 : Monitoring athletic performances, e.g. for determining the work of a user on an exercise apparatus, the completed jogging or cycling distance
• CPC Class Codes: A63B 69/0028 : for running, jogging or speed-walking movable endless bands A63B22/02
• CPC Class Codes: G01C 21/185 : for gravity
• CPC Class Codes: G01C 22/006 : Pedometers
• CPC Class Codes: G16H 20/30 : relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising

Abstract

A method and apparatus for estimating a motion parameter corresponding to a subject element employs one or more accelerometers operable to measure accelerations and a processing system operable to generate a motion parameter metric utilizing the acceleration measurements and estimate the motion parameter using the motion parameter metric.

Claims

1. A method of estimating stride speed corresponding to a subject element, the method comprising:

acquiring an acceleration measurement using one or more accelerometers;

determining an acceleration magnitude and a stride duration from the acceleration measurement using a processing system;

generating a motion parameter metric with the processing system by using the stride duration and acceleration magnitude, wherein the motion parameter metric generated by at least performing an integration of a function of the acceleration magnitude; and

estimating a first value which is function of stride speed with the processing system by using the motion parameter metric and outputting the estimated first value and/or a second value derived from the estimated first value.

2. The method of claim 1, wherein the motion parameter metric is given by:

3. The method of claim 1, wherein the motion parameter metric is given by:

4. The method of claim 1, further including—

determining a gait of the subject element,

selecting at least one of a plurality of motion parameter metrics,

generating the at least one selected motion parameter metric using the stride duration and acceleration magnitude, and

estimating the first value which is a function of stride speed using the at least one generated motion parameter metric and outputting the estimated first value and/or the second value derived from the estimated first value.

5. The method of claim 4, wherein the plurality of motion parameter metrics include—

6. The method of claim 5, wherein Q₃ is selected if the determined gait is a walking gait and at least one of Q₁ through Q₄ is selected for other gaits.

7. The method of claim 1, wherein the first value and/or the second value derived from the estimated first value is output to a remote display device worn by the subject element.

8. The method of claim 1, wherein the first value is estimated by using the generated motion parameter metric and a statistical model that correlates the motion parameter metric to the first value.

9. The method of claim 1, further including acquiring a plurality of acceleration measurements and generating the acceleration magnitude utilizing the acceleration measurements.

10. The method of claim 9, wherein the acceleration magnitude is given by—

r²(t)=α

₀²(t)+ . . . +α

_n²(t),

where r(t) is the acceleration magnitude and α

₀(t) through α

_n(t) represent the plurality of acceleration measurements.

11. An apparatus operable to estimate stride speed corresponding to a subject element, the apparatus comprising:

a plurality of accelerometers each operable to provide a signal corresponding to an acceleration measurement, at least two of the accelerometers being adapted to measure accelerations in two directions separated by an angle greater than zero degrees; and

a processing system coupled with one or more of the accelerometers, the processing system operable to;

calculate a stride duration and an acceleration magnitude using at least one of the acceleration measurements;

generate a motion parameter metric using the stride duration and acceleration magnitude, wherein the motion parameter metric is generated by at least performing an integration of a function of the acceleration magnitude;

estimate a first value which is a function of stride speed using the motion parameter metric; and

output the estimated first value and/or a value derived from the estimated first value to the subject element.

12. The apparatus of claim 11, wherein the motion parameter metric is given by:

13. The apparatus of claim 11, wherein the motion parameter metric is given by:

14. The apparatus of claim 11, wherein the processing system is further operable to—

determine a gait of the subject element using at least one of the acceleration measurements,

select at least one of a plurality of motion parameter metrics from a memory associated with the processing system,

generate the at least one selected motion parameter metric using the stride duration and acceleration magnitude, and

estimate the first value which is a function of stride speed using the at least one generated motion parameter metric and output the estimated first value and/or the value derived from the estimated first value to the subject element.

15. The apparatus of claim 14, wherein the plurality of motion parameter metrics include—

16. The apparatus of claim 15, wherein the processing system selects Q₃ if the determined gait is a walking gait and selects at least one of Q₁ through Q₄ for other gaits.

17. The apparatus of claim 11, wherein the apparatus includes a remote display device operable to receive the estimated first value and/or the second value derived from the estimated first value from the processing system for display to the subject element.

18. The apparatus of claim 11, wherein the processing system estimates the first value by using the generated motion parameter metric and a statistical model that correlates the motion parameter metric to the first value.

19. The apparatus of claim 18, further including a navigation unit comprising a satellite navigation signal receiver operable to determine a current geographic location of the navigation unit, wherein the processing system is operable to adjust the statistical model utilizing information acquired from the navigation unit.

20. The apparatus of claim 19, wherein the processing system is operable to generate an error model utilizing information acquired from the navigation unit to estimate stride speed.