Work comfort evaluating device and work comfort evaluating method

• US 7,486,987 B2
• Filed: 09/16/2004
• Issued: 02/03/2009
• Est. Priority Date: 09/17/2003
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Kuramori, Akira, Koguchi, Noritaka, Sadoyama, Tsugutake, Kamijo, Masayoshi
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): Pani; John
• Application Number:
  US10/942,045
• Publication Number:
  US 20050080350A1
• Time in Patent Office: 1,601 Days
• Field of Search: 600/546, 180/313, 340/576
• US Class Current: 600/546
• CPC Class Codes: A61B 5/18 for vehicle drivers or machine operators
• CPC Class Codes: A61B 5/228 of masticatory organs, e.g. detecting dental force
• CPC Class Codes: A61B 5/389 Electromyography [EMG]

Abstract

A work comfort evaluating device is a device for evaluating a level of comfort of work by measuring myoelectric potentials of plural muscles when the work is done by antagonistic activities of the muscles. The device has a pair of detecting sensors, an amplifier, a signal processing part, a work-load intensity calculating part, and an evaluation part. The sensors sense myoelectric potentials of the muscles at a time of the work. The signal processing part calculates a synchronous contraction intensity of the muscles by using myoelectric potential waveforms. The work-load intensity calculating part calculates a level of a work load intensity in the work. The evaluation part evaluates a level of comfort of the work by normalizing the synchronous contraction intensity by the level of the work load intensity calculated.

Claims

1. A work comfort evaluating device for evaluating a level of comfort of work by measuring myoelectric potentials of muscles when the work is done by antagonistic activities of said muscles, said work comfort evaluating device comprising:

a pair of detecting sensors for sensing myoelectric potentials generated through muscular activities of a human body at a time of work of said muscles;

an amplifier for amplifying said myoelectric potentials sensed by said detecting sensors;

a signal processing part for calculating a synchronous contraction intensity of said muscles by using myoelectric potential waveforms of said amplified myoelectric potentials, wherein the signal processing part is configured to calculate a geometrical average of said myoelectric potential waveforms of said muscles, and is further configured to calculate the root mean square values of the calculated geometrical average within a predetermined period, and wherein the device is configured to use the calculated root mean square values as the synchronous contraction intensity;

a work load intensity calculating part for calculating a level of a work load intensity in said work imparting load to said muscles, said device configured to calculate the level of said work load intensity together with calculating said synchronous contraction intensity; and

an evaluation part for evaluating a level of comfort of said work by normalizing said synchronous contraction intensity by dividing the synchronous contraction intensity by the calculated level of said work load intensity,

wherein said work load intensity calculating part is configured to calculate the level of the work load intensity from the myoelectric potential waveforms of said muscles.

2. The work comfort evaluating device according to claim 1, wherein said muscles are a pair of muscles located at right and left parts of the human body.

3. The work comfort evaluating device according to claim 2, wherein said pair of muscles are deltoid muscles of a shoulder of the human body.

4. The work comfort evaluating device according to claim 1, wherein said work load intensity calculating part is configured to calculate the intensities of muscular loads imparted to said muscles in said work from the myoelectric potential waveforms of said muscles, and is further configured to average and smooth the calculated muscular load intensities in an averaging process to thereby calculate the level of said work load intensity.

5. The work comfort evaluating device according to claim 4, wherein said averaging process is a geometric averaging process.

6. The work comfort evaluating device according to claim 1, wherein said work is a work in which said muscles cooperate to cause an object to be operated to dynamically behave, and said work load intensity calculating part is configured to calculate the level of said work load intensity by measuring a physical quantity representing a dynamic behavior of said object operated by the work.

7. The work comfort evaluating device according to claim 1, wherein said work is a driving of a vehicle that is performed by a driver turning a steering wheel.

8. The work comfort evaluating device according to claim 1, wherein said signal processing part is configured to sample time-series data of the myoelectric potentials of the muscles to generate the myoelectric potential waveforms.

9. The work comfort evaluating device according to claim 4, wherein said workload intensity calculating part is configured to obtain the muscular load intensity by calculating the root mean square values of the myoelectric potential waveform of said muscles within the same period of time when the root mean square values used as the synchronous contraction intensity are calculated.

10. The work comfort evaluating device according to claim 4, wherein the work load intensity calculating part is configured to obtain the work load intensity by calculating separately the muscular load intensities of the muscles.

11. The work comfort evaluating device according to claim 1, wherein the evaluation part is configured to calculate a synchronous contraction rate, which represents a level of mental stress by using the synchronous contraction intensities of the muscles and is configured to evaluate the level of comfort of the work based on the synchronous contraction rate.

12. The work comfort evaluating device according to claim 1, wherein the evaluation part is configured to compare the synchronous contraction rate with preset values for the respective ranks to evaluate the level of comfort of the work.

13. A work comfort evaluating method for evaluating a level of comfort of a work by measuring myoelectric potentials of muscles when the work is done by antagonistic activities of said muscles, said work comfort evaluating method comprising:

sensing and amplifying myoelectric potentials of said muscles, said myoelectric potentials being generated through muscular activities of a human body at a time of work;

calculating a geometrical average of said myoelectric potential waveforms of said muscles, calculating root mean square values of the calculated geometrical average within a predetermined period, and using the calculated root mean square values as a synchronous contraction intensity;

calculating a level of a work load intensity in said work imparting load to said muscles from the myoelectric potential waveforms of said muscles together with the generation of said synchronous contraction intensity; and

evaluating a level of comfort of said work by normalizing said synchronous contraction intensity by dividing the synchronous contraction intensity by the calculated level of said work load intensity.