Method and device for detecting fatigue

• US 9,142,115 B2
• Filed: 07/05/2012
• Issued: 09/22/2015
• Est. Priority Date: 07/26/2011
• Status: Expired due to Fees

• Current Assignee: Holux Technology Incorporated
• Original Assignee: Holux Technology Incorporated
• Inventors: Tao, Teh-Ho
• Primary Examiner(s): MCNALLY, KERRI L
• Application Number:
  US13/542,018
• Publication Number:
  US 20130027208A1
• Time in Patent Office: 1,174 Days
• Field of Search: 340/575, 340/573.1, 340/576, 340/540, 737/60, 382/100, 382/103, 600/300, 600/504, 600/529, 600/481, 600/500
• US Class Current: 1/1
• 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 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety
• CPC Class Codes: A61B 5/18 for vehicle drivers or machine operators
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: B60K 28/06 responsive to incapacity of driver
• CPC Class Codes: G08B 21/06 indicating a condition of sleep, e.g. anti-dozing alarms

Abstract

A method for detecting fatigue is provided herein. The present invention includes the following steps: measuring a plurality of physiological feature data from a user in continuous time to generate a feature sequence; computing the rate of drop and/or calculating the difference of the rate of drop based on the feature sequence; and determining the fatigue level of the user by analyzing the rate of drop and the difference of the rate of drop. A fatigue detecting device is also disclosed here. The present invention can be utilized to effectively monitor the fatigue level of the user.

Claims

1. A method for detecting fatigue comprising the following steps:

obtaining a plurality of physiological feature data of a user from a device in continuous time to generate a feature sequence;

computing a feature curve based on the feature sequence;

computing a rate of drop based on the feature curve;

determining whether a first condition is met, wherein the first condition is that the rate of drop is larger than a threshold for a first duration;

determining the fatigue level of the user depending on the first condition;

calculating a difference of rate of drops;

determining whether a second condition is met, wherein the second condition is that the difference falls within a threshold interval for a second duration; and

determining the fatigue level of the user depending on the first condition and the second condition, wherein a second warning message is generated when the first condition and the second condition are met.

2. The method for detecting fatigue according to claim 1, wherein the rate of drop is an average slope counted per minute;

and the threshold of the first condition is less than −

0.05 and the first duration is greater than 150 seconds.

3. The method for detecting fatigue according to claim 2, wherein a warning message is generated when the first condition is met.

4. The method for detecting fatigue according to claim 1, wherein the rate of drop is an average slope counted per five minutes;

and the threshold of the first condition is less than 0 and the first duration is equal or greater than 140 seconds.

5. The method for detecting fatigue according to claim 4, wherein the threshold interval of the second condition is greater than −

0.001 and less than 0.004.

6. The method for detecting fatigue according to claim 5, wherein the second duration is equal or greater than 60 seconds.

7. The method for detecting fatigue according to claim 1, further comprising:

determining whether a third condition is met, wherein the third condition is that the difference falls within the threshold interval for a third duration; and

determining the fatigue level of the user depending on the first condition, the second condition and the third condition, wherein when the first condition and the third condition are met, a third warning message is generated.

8. The method for detecting fatigue according to claim 7, wherein the third duration is at least 30 seconds greater than the second duration and the threshold interval is greater than −

0.001 and less than 0.004.

9. The method for detecting fatigue according to claim 1, wherein the feature sequence comprises data representative of heart rate per minute updated every second measured from the user or data representative of pulse rate per minute updated every second measured from the user.

10. A device for detecting fatigue comprising:

a measuring unit, for measuring a plurality of physiological feature data from a user in continuous time to generate a feature sequence;

a memory unit, for storing the feature sequence;

a computing unit electrically connected to the measuring unit and the memory unit, for computing a feature curve based on the feature sequence and computing a rate of drop based on the feature curve; and

the computing unit determining whether a first condition is met for obtaining a detection result of the fatigue level of the user, wherein the first condition is that the rate of drop is larger than the threshold for a first duration; and

an output unit electrically connected to the computing unit, for outputting the detection result of the fatigue level;

calculating a difference of the rate of drops; and

determining whether a second condition is met, for obtaining the detection result of the fatigue level of the user, wherein the second condition is that the difference falls within a threshold interval for a second duration.

11. The device for detecting fatigue according to claim 10, wherein the measuring unit can be wire or wireless means.

12. The device for detecting fatigue according to claim 11, wherein the measuring unit operates by wireless means, comprising:

an ultra-wideband emitter, for emitting a ultra-wideband signal; and

a receiver, for receiving a reflected signal of the ultra-wideband signal reflected from the user and receiving the physiological feature data in the continuous time to generate the feature sequence.

13. The device for detecting fatigue according to claim 11, wherein the measuring unit operates by wire means, comprising:

a sensor, for sensing a physiological feature signal by contacting with the user;

a transmission cable connected to the sensor, for transmitting the physiological feature data; and

a receiver, for receiving the physiological feature data in the continuous time to generate the feature sequence.

14. The device for detecting fatigue according to claim 10, wherein the feature sequence comprises data representative of heart rate per minute updated every second measured from the user or data representative of pulse rate per minute updated every second measured from the user.

15. The device for detecting fatigue according to claim 10, wherein the rate of drop is average slope counted per minute;

and the threshold of the first condition is less than −

0.05 and the first duration is equal or greater than 150 seconds.

16. The device for detecting fatigue according to claim 15, wherein a first warning message is generated when the first condition is met.

17. The device for detecting fatigue according to claim 10, wherein the rate of drop is an average slope counted per five minutes;

and the threshold of the first condition is less than 0 and the first duration is equal or greater than 140 seconds.

18. The device for detecting fatigue according to claim 17, wherein the second condition is that the threshold interval is greater than −

0.001 and less than 0.004.

19. The device for detecting fatigue according to claim 18, wherein the second duration is equal or greater than 60 seconds.

20. The device for detecting fatigue according to claim 10, wherein a second warning message is generated when the first condition and the second condition are met.

21. The device for detecting fatigue according to claim 10, wherein the computing unit further comprises:

determining whether a third condition is met, for obtaining the detection result of the fatigue level of the user, wherein the third condition is that the difference falls within the threshold interval for a third duration.

22. The device for detecting the fatigue according to claim 21, wherein the third duration is at least 30 seconds greater than the second duration and the threshold interval is greater than −

0.001 and less than 0.004.

23. The device for detecting the fatigue according to claim 22, wherein a third warning message is generated when the first condition and the third condition are met.

24. The device for detecting fatigue according to claim 10, wherein the output unit is at least one of a display screen or an audio device.