METHOD AND A DEVICE FOR MEASURING MUSCLE SIGNALS

• US 20130261423A1
• Filed: 10/29/2011
• Published: 10/03/2013
• Est. Priority Date: 10/29/2010
• Status: Active Grant

• Current Assignee: Fibrux Oy
• Original Assignee: Jani Mantyjarvi, Mikko Vahasoyrinki
• Inventors: Herrala, Mika, Tavi, Pasi, Mntyjrvi, Jani, Vhsyrinki, Mikko
• Granted Patent: US 10,357,170 B2
• Time in Patent Office: Days
• US Class Current: 600/393
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/7253 characterised by using transforms

Abstract

A method, system and apparatus for determining the state of a muscle between a normal non-tired state, a tired state and a passive involuntary tension state. A signal from the muscle is recorded at rest by using an electrode arrangement, where an earth body may prevent the electrodes from picking up signals beyond the extent of the earth body. The frequency content of the signal is determined by spectral analysis, e.g. by computing a moment of the spectrum. A normal frequency content indicates a non-tired muscle state, whereas a low and a high frequency content indicate a tired and a passive involuntary tension muscle state.

Claims

1. A method for analyzing muscle signals, the method comprising:

receiving a signal, the signal having been measured from a muscle in a resting state,

determining a measure indicative of frequency content of said signal, the method characterized in that the method further comprises;

determining a measure indicative of strength of said signal in a high frequency, wherein said high frequency essentially corresponds to frequencies produced by a muscle in a passive involuntary tension state, and wherein said high frequency is higher in frequency than a normal frequency, wherein said normal frequency essentially corresponds to frequencies produced by a muscle in a non-tired state, and

determining that a muscle is in a passive involuntary tension state based on said measure indicative of the strength of said signal in a high frequency.

2. A method according to claim 1, said method for guiding an exercise using muscle signal analysis, said method further comprising:

acquiring a signal from a muscle at rest from top of said muscle,

determining a moment value of a spectrum of said signal, wherein said moment is indicative of a measure determined by multiplying a frequency value of a frequency bin with an amplitude value of the same bin to form a bin product and summing bin products for different frequencies, and wherein said moment value corresponds to frequency content of said signal,

determining whether said moment has a normal value, a low value or a high value, corresponding to a normal, low and high frequency content of said signal,

determining that a muscle is in a non-tired state if said moment has a normal value,

determining that a muscle is in a tired state if said moment has a low value,

determining that a muscle is in a passive involuntary tension state if said moment has a high value, and

guiding an exercise using said determined state of said muscle.

3-10. -10. (canceled)

11. An apparatus for determining the state of a muscle, comprising a processor, memory including computer program code, the memory and the computer program code configured to, with the processor, cause the apparatus to:

receive a signal, the signal having been measured from a muscle in a resting state,

determine a measure indicative of frequency content of said signal,

the apparatus characterized in that it further comprises computer program code that cause the apparatus to;

determine a measure indicative of strength of said signal in a high frequency, wherein said high frequency essentially corresponds to frequencies produced by a muscle in a passive involuntary tension state, and wherein said high frequency is higher in frequency than a normal frequency, wherein said normal frequency essentially corresponds to frequencies produced by a muscle in a non-tired state, and

determine that a muscle is in a passive involuntary tension state based on said measure indicative of the strength of said signal in a high frequency.

12. An apparatus according to claim 11, further comprising computer program code configured to, with the processor, cause the apparatus to:

acquire a signal from a muscle from top of said muscle,

determine a moment value of a spectrum of said signal, wherein said moment is indicative of a measure determined by multiplying a frequency value of a frequency bin with an amplitude value of the same bin to form a bin product and summing bin products for different frequencies, and wherein said moment value corresponds to frequency content of said signal,

determine whether said moment has a normal value, a low value or a high value, corresponding to a normal, low and high frequency content of said signal,

determine that a muscle is in a non-tired state if said moment has a normal value,

determine that a muscle is in a tired state if said moment has a low value, and

determine that a muscle is in a passive involuntary tension state if said moment has a high value.

13. An apparatus according to claim 11, comprising:

an electrode arrangement comprising;

at least two electrodes of conducting material arranged to make contact with the skin when said electrode arrangement is operated,

an electrical insulator surrounding at least one of said at least two electrodes, and

a passive ground body of a conducting material arranged to make contact with the skin when said electrode arrangement is operated, said ground body surrounding said at least two electrodes to limit said at least two electrodes from picking up a signal from outside of the extent of said ground body.

14. An apparatus according to claim 13, further comprising:

a unit for processing said signal measured from a muscle,

and

an indicator for indicating that a muscle is in a passive involuntary tension state based on said measure indicative of the strength of said signal in a high frequency.

15. An apparatus according to claim 13, wherein said electrode arrangement comprises at least two pairs of electrodes, and said at least two pairs of electrodes have a different distance between the electrodes in the pair for creating a different depth sensitivity for the said at least two pairs of electrodes.

16. An apparatus according to claim 15, wherein said at least two pairs of electrodes are arranged in either a linear arrangement essentially along one line or in a crossed setting such as the lines between electrodes in the electrode pairs forming a straight angle cross.

17. A system for determining the state of a muscle, comprising an electrode arrangement, a processor, memory including computer program code, the memory and the computer program code configured to, with the processor, cause the system to:

acquire a signal from a muscle,

determine a measure indicative of frequency content of said signal,

the system characterized in that it further comprises computer program code that cause the system to;

determine a measure indicative of strength of said signal in a high frequency, wherein said high frequency essentially corresponds to frequencies produced by a muscle in a passive involuntary tension state, and wherein said high frequency is higher in frequency than a normal frequency, wherein said normal frequency essentially corresponds to frequencies produced by a muscle in a non-tired state, and

determine that a muscle is in a passive involuntary tension state based on said strength of said signal in a high frequency.

18. A system according to claim 17, wherein said electrode arrangement comprises:

at least two electrodes of conducting material arranged to make contact with the skin when said electrode arrangement is operated,

an electrical insulator surrounding at least one of said at least two electrodes, and

a passive ground body of a conducting material arranged to make contact with the skin when said electrode arrangement is operated, said ground body surrounding said at least two electrodes to limit said at least two electrodes from picking up a signal from outside of the extent of said ground body.

20. A system according to claim 17, wherein said electrode arrangement comprises at least two pairs of electrodes, and said at least two pairs of electrodes have a different distance between the electrodes in the pair for creating a different depth sensitivity for the said at least two pairs of electrodes.

21. An apparatus according to claim 20, wherein said at least two pairs of electrodes are arranged in either a linear arrangement essentially along one line or in a crossed setting such as the lines between electrodes in the electrode pairs forming a straight angle cross.

22. A computer program product embodied on a non-transitory computer readable medium, the computer program product comprising computer instructions that, when executed on at least one processor of a system, cause the system to:

receive a signal, the signal having been measured from a muscle in a resting state,

determine a frequency content of said signal,

the computer program product characterized in that it further comprises instructions that cause the system to;

determine a strength of said signal in a high frequency, wherein said high frequency essentially corresponds to frequencies produced by a muscle at rest in a passive involuntary tension state, and wherein said high frequency is higher in frequency than a normal frequency, wherein said normal frequency essentially corresponds to frequencies produced by a muscle at rest in a non-tired state, and

determine that a muscle is in a passive involuntary tension state based on said strength of said signal in a high frequency.

23. A computer program product according to claim 22, comprising computer instructions that, when executed on at least one processor of a system, cause the system to:

acquire a signal from a muscle at rest from top of said muscle,

determine a moment value of a spectrum of said signal, wherein said moment is indicative of a measure determined by multiplying a frequency value of a frequency bin with an amplitude value of the same bin to form a bin product and summing bin products for different frequencies, and wherein said moment value corresponds to frequency content of said signal,

determine whether said moment has a normal value, a low value or a high value, corresponding to a normal, low and high frequency content of said signal,

determine that a muscle is in a non-tired state if said moment has a normal value,

determine that a muscle is in a tired state if said moment has a low value,

determine that a muscle is in a passive involuntary tension state if said moment has a high value, and

guide an exercise using said determined state of said muscle.