METHOD AND SYSTEM FOR DETECTING FATIGUE IN AN ATHLETE

• US 20170228996A1
• Filed: 02/05/2016
• Published: 08/10/2017
• Est. Priority Date: 02/05/2016
• Status: Active Grant

• Current Assignee: Logitech Europe S A (Logitech International SA)
• Original Assignee: Logitech Europe S A (Logitech International SA)
• Inventors: Bonanno, Daniel, Chardon, Jean-Michel, Theytaz, Olivier
• Granted Patent: US 10,490,051 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2503/10 Athletes
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/112 Gait analysis
• CPC Class Codes: A61B 5/486 Bio-feedback A61B5/375 takes precedence
• CPC Class Codes: A61B 5/6803 Head-worn items, e.g. helmets, masks, headphones or goggles
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G08B 21/0438 Sensor means for detecting
• CPC Class Codes: G08B 21/0453 worn on the body to detect health condition by physiological monitoring, e.g. electrocardiogram, temperature, breathing detecting, measuring or recording for diagnostic purposes A61B5/00
• CPC Class Codes: G16H 20/30 relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

A method of detecting fatigue of a user during an activity includes acquiring performance data for the user during the activity and computing metrics related to the performance data. The method also includes determining that the metrics exceed a predetermined threshold, generating an alert, and communicating the alert to the user.

Claims

1. A method of detecting fatigue of a user during an activity, the method comprising:

acquiring performance data for the user during the activity;

computing metrics related to the performance data;

determining that the metrics exceed a predetermined threshold;

generating an alert; and

communicating the alert to the user.

2. The method of claim 1 further comprising acquiring a heart rate signal of the user, wherein:

the performance data comprises a speed of the user; and

the metrics comprise a heart rate to speed ratio.

3. The method of claim 1 wherein the performance data comprises a speed of the user and the metrics comprise a variability of a step cycle time.

4. The method of claim 3 wherein the variability of the step cycle time is a standard deviation of the step cycle time divided by a mean of the step cycle time.

5. The method of claim 1 wherein the performance data comprises a plurality of heart rate periods and the metrics comprise a variability of a fatigue ratio equal to a ratio of a standard deviation of the plurality of heart rate periods to a mean of the plurality of heart rate periods over a predefined number of periods.

6. The method of claim 1 further comprising acquiring slope information for terrain in a vicinity of the user, wherein computing metrics is performed for portions of the activity performed on level terrain.

7. The method of claim 1 wherein acquiring the performance data comprises measuring vertical acceleration as a function of time during at least a portion of the activity.

8. The method of claim 1 wherein the alert comprises at least one of a visual signal from a display or a sound from a speaker.

9. A method of alerting a user of fatigue during exercise, the method comprising:

a) acquiring a heart rate signal for the user during the exercise;

b) acquiring a speed signal for the user during the exercise;

c) determining a slope of terrain in a vicinity of the user;

d) computing a heart rate to speed ratio for the user during the exercise;

e) comparing the heart rate to speed ratio to a predetermined threshold;

f) iterating elements a) through e) until the heart rate to speed ratio is greater than the predetermined threshold; and

g) generating an alert to the user based, at least in part, on the heart rate to speed ratio being greater than the predetermined threshold.

10. The method of claim 9 wherein determining the slope of the terrain comprises selecting a set of path segments that are substantially level.

11. The method of claim 10 wherein comparing the heart rate to speed ratio to the predetermined threshold is performed for the selected set of path segments that are substantially level.

12. The method of claim 9 wherein the predetermined threshold is a function of historical data combined with a fixed value defined experimentally.

13. A method of alerting a user of fatigue during exercise, the method comprising:

a) acquiring a speed signal for the user during the exercise;

b) determining a slope of terrain in a vicinity of the user;

c) acquiring contact time and step cycle time using an accelerometer;

d) computing a step cycle time and a variability of the step cycle time;

e) comparing the variability of the step cycle time to a predetermined threshold;

f) generating an alert to the user if the variability of the step cycle time is greater than the predetermined threshold; and

g) iterating elements a) through f) until the variability of the step cycle time is greater than the predetermined threshold.

14. The method of claim 13 wherein determining the slope of the terrain comprises selecting a set of path segments that are substantially level.

15. The method of claim 13 wherein computing the step cycle time comprises averaging a step cycle time for a series of step cycles.

16. A method of alerting a user to fatigue during exercise, the method comprising:

a) acquiring a heart rate signal during the exercise;

b) computing a plurality of heart rate periods and statistical measures for the plurality of heart rate periods;

c) computing a variation of the statistical measures for the plurality of heart rate periods;

d) comparing the variation of the statistical measures to a predetermined threshold;

e) iterating elements a) through d) until the variation of the statistical measures is greater than the predetermined threshold; and

f) generating an alert to the user once the variation of the statistical measures is greater than the predetermined threshold.

17. The method of claim 16 wherein the statistical measures include a fatigue ratio.

18. The method of claim 17 wherein the fatigue ratio comprises a standard deviation of the plurality of heart rate periods divided by a mean of the plurality of heart rate periods over a predefined number of periods.

19. The method of claim 16 wherein acquiring the heart rate signal during the exercise comprises determining that a slope of terrain in a vicinity of the user is substantially level.

20. The method of claim 19 wherein acquiring the heart rate signal during the exercise comprises determining that a slope of terrain in a vicinity of the user is characterized by a positive value, wherein the predetermined threshold is associated with the positive value of the slope of terrain in the vicinity of the user.

21. A method of alerting a user to instantaneous fatigue during interval training, the method comprising:

a) acquiring a first heart rate signal after a high intensity period of the interval training;

b) acquiring a second heart rate signal after a low intensity period of the interval training;

c) determining if a decrease in heart rate between the first heart rate signal and the second heart rate signal is less than or equal to a predetermined threshold; and

d) generating an alert to the user if the decrease in heart rate is less than or equal to the predetermined threshold.

22. The method of claim 21 further comprising e) iterating elements a) through d) until the decrease in heart rate is less than or equal to the predetermined threshold.

23. The method of claim 21 wherein the first heart rate is acquired at an end of the high intensity period and the second heart rate is acquired at an end of the low intensity period adjacent to and following the high intensity period.

24. A method of alerting a user to accumulated fatigue after interval training, the method comprising

acquiring a first heart rate signal at a first time following a last high intensity period of the interval training;

acquiring a second heart rate signal at a second time after the first time;

acquiring a third heart rate signal at a third time after the second time;

determining that differences between at least the first heart rate signal, the second heart rate signal, and the third heart rate signal are less than or equal to a set of predetermined thresholds; and

generating an alert to the user to indicate accumulated fatigue.

25. The method of claim 24 wherein the difference between the first heart rate signal and the second heart rate signal is less than or equal to a first predetermined threshold and the difference between the second heart rate signal and the third heart rate signal is less than or equal to a second predetermined threshold.