Apparatus and Method for Counting Exercise Repetitions

• US 20090221403A1
• Filed: 03/03/2008
• Published: 09/03/2009
• Est. Priority Date: 03/03/2008
• Status: Active Grant

• Current Assignee: IDT Technology Limited (IDT International Limited)
• Original Assignee: IDT Technology Limited (IDT International Limited)
• Inventors: Chan, Raymond, Li, Li, Leong, Mun Hoong
• Granted Patent: US 7,877,226 B2
• Time in Patent Office: Days
• US Class Current: 482/8
• CPC Class Codes: A63B 2071/0661 arranged on the user
• CPC Class Codes: A63B 21/06 User-manipulated weights
• CPC Class Codes: A63B 2220/17 Counting, e.g. counting periodical movements, revolutions or cycles, or including further data processing to determine distances or speed
• CPC Class Codes: A63B 2220/40 Acceleration
• CPC Class Codes: A63B 2220/836 Sensors arranged on the body of the user
• CPC Class Codes: A63B 2244/20 Swimming
• 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 5/20 Skipping-ropes or similar devices rotating in a vertical plane
• CPC Class Codes: A63B 69/0028 for running, jogging or speed-walking movable endless bands A63B22/02
• CPC Class Codes: G01C 22/006 Pedometers

Abstract

An apparatus and method for counting exercise repetitions are provided for accurate counting exercise repetition even when an exerciser attaches the apparatus in different places and along different orientations of his or her body. The apparatus and method utilizing acceleration data along at least three axes and determines a valid step if at least one of the acceleration profiles falls within at least one of said thresholds. Moreover, a method of identifying an optimal axis for exercise repetition measurement is disclosed by comparing the acceleration profiles of previous steps with amplitude, cycle and rhythm thresholds.

Claims

1. An apparatus for counting exercise repetitions comprising

a) three accelerometers simultaneously measuring the acceleration profiles of an exerciser along three different directions;

b) a data processing unit executing an algorithm to add to a repetition count when at least one of said acceleration profiles falls within thresholds;

c) a display connected to said data processing unit; and

d) a memory connected to said data processing unit;

wherein said apparatus counts said exercise repetitions of said exerciser irrespective of an orientation of said apparatus.

2. The apparatus of claim 1, wherein each of said three accelerometers measure acceleration along one of the three orthogonal axes in three dimensional spaces.

3. The apparatus of claim 1, wherein said acceleration profiles comprise repetitive waveforms.

4. The apparatus of claim 3, wherein said thresholds are computed from average values of a waveform.

5. The apparatus of claim 1, wherein said acceleration profiles comprise an amplitude movement and an acceleration cycle, and said repetition count is incremented when said amplitude movement falls within an amplitude threshold and said acceleration cycle falls within a cycle threshold.

6. The apparatus of claim 5, wherein said repetition count is incremented by two when said amplitude movement falls within said amplitude threshold and said acceleration cycle is longer than one cycle threshold but shorter than twice of said cycle threshold.

7. The apparatus of claim 1, wherein an optimal axis for counting exercise repetition is identified, said optimal axis being the axis where said acceleration profile satisfies a second amplitude threshold, a cycle threshold and a rhythm threshold.

8. The apparatus of claim 1, wherein said apparatus enters sleeping mode if no repetitions are counted within a predetermined duration of time.

9. The apparatus of claim 1, wherein said apparatus is a pedometer.

10. The apparatus of claim 1, wherein said apparatus is a swim stroke counter that counts a number of swimming strokes of said exerciser.

11. The apparatus of claim 1, wherein said apparatus is an exercise event counter that counts a number of exercise events that said exerciser completes.

12. A method of counting exercise repetitions comprising the steps of

a) simultaneously measuring the acceleration of an exerciser along at least three axes;

b) comparing the acceleration profiles on each axis with thresholds; and

c) adding to a repetition count when at least one of said acceleration profiles falls within at least one of said thresholds.

13. The method of claim 12, wherein said acceleration profiles comprise repetitive waveform and said thresholds are computed from a previously stored waveform.

14. The method of claim 12, wherein said acceleration profile comprises amplitude movement and acceleration cycle and said adding step increments said repetition count when said amplitude movement falls within an amplitude threshold and said acceleration cycle falls within a cycle threshold.

15. The method of claim 14, wherein said repetition count is incremented by two when said amplitude movement falls within said amplitude threshold and said acceleration cycle is longer than one cycle threshold but shorter than twice of said cycle threshold.

16. The method of claim 13, wherein said comparing step identifies an optimal axis for comparison, said optimal axis being the axis satisfies a second amplitude threshold, a cycle threshold and a rhythm threshold.

17. A method of identifying a new optimal axis for counting exercise repetitions comprising

a) simultaneously measuring the acceleration of an exerciser along at least three axes;

b) detecting a first valid repetition along a first axis when an acceleration profile on said first axis satisfies a first amplitude threshold range and a cycle threshold range first before other two axes;

said axis being a first axis;

c) determining a previous optimal axis that is different from said first axis as a second axis;

d) computing a first amplitude indicator, a first cycle indicator and a first rhythm indicator from said first axis, and a second amplitude threshold, a second cycle threshold range and a rhythm threshold range from said second axis;

e) identifying said first axis as said new optimal axis when said first amplitude indicator satisfies said second amplitude threshold;

said first cycle indicator is within said second cycle threshold range and said first rhythm indicator is within said rhythm threshold range.

18. The method of claim 17, wherein said first amplitude indicator is calculated from the ratios of amplitudes and cycles of a predetermined number of previous steps on said first axis;

said second amplitude threshold is calculated from the ratios of amplitudes and cycles of a predetermined number of previous steps on said second;

said first cycle indicator is calculated from the cycles of said predetermined number of previous steps on said first axis; and

said second cycle threshold range is calculated from the cycles of said predetermined number of previous steps on said second axis.

19. The method of claim 17, wherein said first rhythm indicator is calculated from the mean of absolute differences between cycles of said predetermined number of previous steps and the mean value thereof on said first axis;

and said rhythm threshold range is calculated from the mean of absolute differences between cycles of said predetermined number of previous steps and the mean value thereof on said second axis.

20. The method of claim 17 wherein said new optimal axis replaces said previous optimal axis.