JP2023124733A - Muscle contraction detection sensor - Google Patents

Abstract

To provide an improved muscle contraction detection sensor.SOLUTION: There is provided an improved muscle contraction detection sensor 1 comprising: a substrate 2; at least two pressing members 3,4 arranged on the substrate 2; and at least two reaction force detecting parts 6, 7 for detecting reaction force which is received on the pressing members 3, 4. The pressing members 3, 4 comprise: the first pressing member 3; and the second pressing member 4 receiving reaction force caused by the pressing toward muscles when the muscles contract smaller than that received on the first pressing member 3. The reaction force detecting parts 6, 7 comprise: the first reaction force detecting part 6 for detecting the reaction force received on the first pressing member 3; and the second reaction force detecting part 7 for detecting the reaction force received on the second pressing member 4. On the basis of a difference or ratio change between the reaction force detected by the first reaction force detecting part 6, and the reaction force detected by the second reaction force detecting part 7, contraction of the muscles is detected. The muscle contraction detection sensor 1 further comprises a pair of flexible sheet-shaped electrodes 8 arranged respectively on surfaces of the pressing members 3, 4.SELECTED DRAWING: Figure 1

Description

The present invention relates to a muscle contraction detection sensor that detects muscle contraction.

Conventionally, as a muscle contraction detection sensor for measuring muscle contraction, that is, the amount of muscle activity, a substrate is arranged facing the muscle to be detected, and is arranged on the substrate, and is pressed toward the muscle and received by the pressing. At least two pressing members having different reaction forces, and at least two reaction force detection units for detecting the reaction forces received by the corresponding pressing members, wherein the pressing members are composed of the first pressing member and the muscle. a second pressing member that receives a smaller reaction force than the first pressing member when pressed toward the first pressing member, wherein the reaction force detection unit detects the first reaction force that the first pressing member receives and a second reaction force detection unit that detects the reaction force received by the second pressing member, wherein the reaction force received by the first pressing member detected by the first reaction force detection unit and the There is known one configured to detect muscle contraction based on the difference or ratio change between the reaction force received by the second pressing member detected by the reaction force detection unit 2 (for example, Patent Reference 1).

Japanese Patent No. 6875755

The above-described conventional muscle contraction detection sensor is based on the difference or ratio change between the reaction force received by the first pressing member and the reaction force received by the second pressing member. It has the feature of being able to detect muscle contraction without measuring surface myoelectric potential), but there is room for further improvement using this feature.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to provide an improved muscle contraction detection sensor.

The muscle contraction detection sensor of the present invention includes a substrate arranged opposite to a muscle to be detected, and at least two substrates arranged on the substrate, pressed against the muscle, and having different reaction forces received by the pressing. and at least two reaction force detection units for detecting reaction forces received by the corresponding pressing members, wherein the pressing members are composed of the first pressing member and the muscle when the muscles contract. a second pressing member that receives a smaller reaction force than the first pressing member when pressed against the muscle, and the reaction force detection unit detects the reaction force received by the first pressing member. a first reaction force detection unit; and a second reaction force detection unit that detects a reaction force received by the second pressing member, wherein the first reaction force detected by the first reaction force detection unit A muscle contraction detection sensor that detects muscle contraction based on a difference or a change in the ratio between the reaction force received by the pressing member and the reaction force received by the second pressing member detected by the second reaction force detection unit. and further comprising a pair of flexible sheet-like electrodes each fixed to the surface of the pressing member.

In the muscle contraction detection sensor of the present invention, in the configuration described above, a pulse generator for inputting a pulse signal to the pair of electrodes; Based on a change in the difference or ratio between the reaction force received by the first pressing member detected by the reaction force detection unit and the reaction force received by the second pressing member detected by the second reaction detection unit and a control unit that feedback-controls the operation of the pulse generator based on the amount of contraction of the muscle detected by the pulse generator.

In the muscle contraction detection sensor of the present invention, in the configuration described above, the myoelectric potential of the muscle detected by the pair of electrodes and the reaction force received by the first pressing member detected by the first reaction force detection unit are detected. The fatigue of the muscle is measured from the difference from the reaction force received by the second pressing member detected by the second reaction force detection unit or the difference from the contraction amount of the muscle detected based on the change in ratio. It is preferable to further have a fatigue measuring section that

In the muscle contraction detection sensor of the present invention, in the configuration described above, it is preferable that the first pressing member and the second pressing member are each formed in a flexible bag-like shape with a fluid sealed therein.

In the muscle contraction detection sensor of the present invention, in the above configuration, the pair of second pressing members whose inner spaces are connected to each other by a connecting channel, and the pair of second pressing members arranged between the pair of pressing members. one of the electrodes is fixed to the surface of one of the second pressing members, and the other of the electrodes is fixed to the surface of the other of the second pressing members. is preferred.

In the muscle contraction detection sensor of the present invention, the projection height of the first pressing member from the substrate in an unloaded state is equal to the projection height of the second pressing member from the substrate in an unloaded state. preferably higher than

According to the present invention, an improved muscle contraction detection sensor can be provided.

1 is a plan view of a muscle contraction detection sensor that is an embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view of the muscle contraction detection sensor shown in FIG. 1 taken along line AA; 2 is a cross-sectional view of the muscle contraction detection sensor shown in FIG. 1 when worn on a human body; FIG. FIG. 2 is a cross-sectional view of the muscle contraction detection sensor shown in FIG. 1 when a muscle contracts while the sensor is worn on a human body; 2 is a block diagram showing a control system when the muscle contraction detection sensor shown in FIG. 1 is used as a quantitative electrical stimulation device; FIG. 2 is a block diagram showing a control system when the muscle contraction detection sensor shown in FIG. 1 is used as a muscle fatigue measuring device; FIG. 3 is a cross-sectional view of a modification of the muscle contraction detection sensor shown in FIG. 2; FIG. 3 is a cross-sectional view of another modification of the muscle contraction detection sensor shown in FIG. 2; FIG.

Hereinafter, the present invention will be described more specifically by way of example with reference to the drawings.

A muscle contraction detection sensor 1, which is an embodiment of the present invention shown in FIGS. 1 and 2, is attached to a part such as an arm or a leg of a human body and is capable of detecting muscle contraction at that part. .

A muscle contraction detection sensor 1 has a substrate 2 . The substrate 2 is arranged so as to face the muscle to be detected, and is fixed to the human body while being biased toward the muscle using a fixing tool such as an elastic belt.

The substrate 2 can be made of, for example, a synthetic resin material such as engineering plastic or a metal material such as brass. It is preferable that the substrate 2 has a rigidity that does not cause excessive deformation during use. In this embodiment, the substrate 2 is formed in a rectangular plate shape having a width corresponding to the muscle width (the width in the direction perpendicular to the stretching direction) of the muscle to be detected by the muscle contraction detection sensor 1. 2, a stepped portion 2a for discharging upward is integrally provided in the central portion of the upper surface which is the middle upper side.

Note that the width of the substrate 2 can be varied in accordance with the muscle to be detected. Further, the shape of the substrate 2 is not limited to a rectangular plate shape, and can be variously changed such as a circular plate shape, for example.

At least two pressing members are arranged on the upper surface of the substrate 2 which is the upper side in FIG. In this embodiment, a first pressing member 3 is arranged on the upper surface of the stepped portion 2a of the substrate 2, and a pair of second pressing members 4 are arranged on the upper surface of both side portions of the stepped portion 2a of the substrate 2. there is That is, in this embodiment, one first pressing member 3 is arranged between a pair of second pressing members 4 on the upper surface of the substrate 2 .

A first pressing member 3 and a pair of second pressing members 4 protrude upward from the upper surface of the substrate 2, respectively. When fixed to the body, each is pressed toward the muscle to be detected. In other words, when the muscle contraction detection sensor 1 is attached to the human body, the first pressing member 3 and the pair of second pressing members 4 are pressed against the part of the human body where the muscle is located.

In this embodiment, the first pressing member 3 and the pair of second pressing members 4 are made of a synthetic resin material such as vinyl chloride resin so that fluid (in this embodiment, air) is introduced into the internal spaces 3a and 4a. It is in the form of a flexible sealed bag. In an unloaded state, that is, in a natural state where the muscles are not pressed against each other, the pressure in the internal space 3a of the first pressing member 3 and the pressure in the internal space 4a of the pair of second pressing members 4 are equal. .

More specifically, the first pressing member 3 is smaller than the substrate 2 in a plan view and has a rectangular bag shape corresponding to the stepped portion 2a. is placed on the top of the

Each of the pair of second pressing members 4 has a rectangular bag shape that is smaller than the substrate 2 and larger than the first pressing member 3 in plan view. One second pressing member 4 is arranged on the upper surface of the substrate 2 on one side of the stepped portion 2a, and the other second pressing member 4 is arranged on the upper surface of the substrate 2 on the other side of the stepped portion 2a. is placed on the top of the In the pair of second pressing members 4, the internal spaces 4a are connected to each other by the connecting channel 5, and the pressures in the internal spaces 4a are the same.

As described above, in the muscle contraction detection sensor 1 of the present embodiment, as the pressing members, the pair of second pressing members 4 whose internal spaces 4a are connected to each other by the connection flow path 5, and the pair of second pressing members 4 and one first pressing member 3 arranged between the members 4 . As a result, when the muscle contraction detection sensor 1 is attached to a predetermined portion of the human body, the substrate 2 is stably supported on the predetermined portion of the human body by the pair of second pressing members 4, while the first pressing member 3 is attached to the human body. can be reliably pressed against a predetermined portion of the Therefore, the substrate 2 can be stably pressed toward the muscle without being greatly inclined from the posture facing the muscle. In addition, by suppressing the inclination of the substrate 2, the substrate 2 can be prevented from coming into direct contact with the human body, and the muscle contraction detection accuracy of the muscle contraction detection sensor 1 can be increased.

In addition, in the muscle contraction detection sensor 1 of the present embodiment, the first pressing member 3 and the pair of second pressing members 4 are configured in a flexible bag-like configuration in which fluid is sealed inside. As a result, when the first pressing member 3 and the pair of second pressing members 4 are pressed against the human body toward the muscles, the first pressing member 3 and the pair of second pressing members 4 Each of them is flexibly deformed, and the skin receives uniform pressure from the first pressing member 3 and the pair of second pressing members 4, so that the feeling that the human body receives can be improved. That is, when the muscle contraction detection sensor 1 is attached to the human body, pain and discomfort felt by the human body can be reduced. In particular, when a compressible fluid such as air is enclosed in the internal space 3a of the first pressing member 3 and the internal space 4a of the second pressing member 4, the first pressing member 3 and a pair of To make a second pressing member 4 softer and to improve a feeling received by a human body when the first pressing member 3 and a pair of second pressing members 4 are pressed against the human body toward muscles. can be done. As a result, the muscle contraction detection sensor 1 can be worn more comfortably when attached to the human body.

In this embodiment, the first pressing member 3 and the second pressing member 4 are configured such that air is enclosed as a fluid in the internal spaces 3a and 4a, respectively. For example, a configuration in which a compressible fluid (gas) other than air or an incompressible fluid such as water is enclosed in 4a may be employed. However, if the internal space 3a of the first pressing member 3 and the internal space 4a of the second pressing member 4 are filled with air, the cost of the muscle contraction detecting sensor 1 can be reduced, which is preferable.

In an unloaded state (a natural state in which no muscle is pressed against the muscle), as can be seen from FIG. 4 is higher than the protrusion height from the upper surface of the substrate 2 . The comparison of the protrusion heights of the first pressing member 3 and the pair of second pressing members 4 is based on the upper surface of the same portion of the substrate 2, and the portion where the stepped portion 2a is not provided. The upper surface of the substrate 2 at the position may be used as the reference, or the upper surface of the portion where the stepped portion 2a is provided may be used as the reference.

Thus, in this embodiment, the projection height of the first pressing member 3 from the substrate 2 in the no-load state is greater than the projection height from the substrate 2 of the pair of second pressing members 4 in the no-load state. Therefore, when the muscle contraction detecting sensor 1 is attached to the human body and the first pressing member 3 and the pair of second pressing members 4 are pressed against a muscle part of the human body, the pair of second The reaction force that the second pressing member 4 receives from the pressing is smaller than the reaction force that the first pressing member 3 receives from the pressing.

The heights of the pair of second pressing members 4 protruding from the upper surface of the substrate 2 are preferably the same, but may be different.

In order to detect the reaction force (pressure) that the first pressing member 3 receives from the human body when the first pressing member 3 is directed toward the muscles and pressed against the human body, the substrate 2 includes a first reaction force detection unit. 6 is provided. In this embodiment, the first reaction force detection unit 6 is composed of a plate-shaped pressure sensor, and is mounted on the substrate 2 by being fitted on the upper surface of the stepped portion 2a of the substrate 2 . A pressure detection surface 6 a of the first reaction force detection portion 6 is flush with the upper surface of the stepped portion 2 a of the substrate 2 and is in contact with the first pressing member 3 .

In order to detect the reaction force (pressure) that the second pressing member 4 receives from the human body when the second pressing member 4 is pressed against the muscle, the substrate 2 is provided with a second reaction force detection unit. 7 is provided. In the present embodiment, the second reaction force detection unit 7 is also composed of a plate-like pressure sensor, and the pressure sensor is applied to the upper surface on one side of the stepped portion 2a of the substrate 2 directly below the second pressing member 4. It is mounted on the substrate 2 by being fitted. A pressure sensing surface 7 a of the second reaction force sensing portion 7 is flush with the upper surface of the substrate 2 and is in contact with one of the second pressing members 4 . In the present embodiment, the pair of second pressing members 4 have internal spaces 4a in which air is sealed in each other and are connected by the connecting channel 5, so that the pair of second pressing members 4 receives from the human body. The reaction force can be accurately detected by one second reaction force detector 7 that contacts only one of the second pressing members 4 .

As the plate-shaped pressure sensors constituting the first reaction force detection unit 6 and the second reaction force detection unit 7, for example, strain gauge type pressure transducers can be used. As plate-like pressure sensors constituting the first reaction force detection unit 6 and the second reaction force detection unit 7, instead of the strain gauge type pressure transducers described above, the first pressing member 3 and the second It is also possible to use another type that can detect the reaction force received by the two pressing members 4 and output it as an electric signal or the like.

The muscle contraction detection sensor 1 is attached to the human body, and in a state in which the first pressing member 3 and the pair of second pressing members 4 are pressed against a muscle part of the human body, the first reaction force detection unit 6 Based on the change in the difference or ratio between the reaction force received by the first pressing member 3 detected by the second reaction force detection unit 7 and the reaction force received by the pair of second pressing members 4 detected by Muscle contraction can be detected.

Next, a method for detecting or measuring muscle contraction using the muscle contraction detection sensor 1 will be described.

First, as shown in FIG. 3, the muscle contraction detection sensor 1 is attached to a predetermined part such as an arm of a human body using a fixture (not shown) such as an elastic belt so as to be in direct contact with the skin SK. That is, the muscle contraction detection sensor 1 is arranged such that the substrate 2 faces a muscle (not shown) to be detected, and the first pressing member 3 and the pair of second pressing members 4 are to be detected with respect to the substrate 2. It is attached to a predetermined part of the human body by a fixture so that the pair of electrodes 8 fixed to the surface of the second pressing member 4 are in direct contact with the surface of the skin SK while facing the muscle side. When the muscle contraction detection sensor 1 is attached to a predetermined part of the human body, the pair of electrodes 8 are in direct contact with the surface of the skin SK, and the first pressing member 3 and the pair of second pressing members 4 are placed on the muscle side. It will be in a state of being pressed against the human body.

The fixture is elastic enough to generate a tension capable of pressing the muscle contraction detection sensor 1 against a predetermined part of the human body to the extent that the substrate 2, the first pressing member 3 and the pair of second pressing members 4 are not excessively deformed. A belt is preferable, but other members such as a corset or a supporter may be used.

When the muscle contraction detection sensor 1 is attached to a predetermined portion of the human body and the first pressing member 3 and the pair of second pressing members 4 are pressed against the human body toward the muscle side, the first pressure is applied. The pressing member 3 and the pair of second pressing members 4 receive a reaction force from the skin SK of the human body and are slightly deformed. Even in this state, as in the natural state, the protrusion height of the first pressing member 3 from the upper surface of the substrate 2 is higher than the protrusion height of the second pressing member 4 from the upper surface of the substrate 2. there is

At this time, the skin SK is flexibly bent and comes into contact with both the first pressing member 3 and the second pressing member 4, so that the reaction force _FB from the skin SK is applied to the first pressing member 3, A reaction force _FD from the skin SK is applied to the second pressing member 4 of . These reaction forces F _B and F _D are detected by the first reaction force detection unit 6 and the second reaction force detection unit 7, respectively, and are detected by the first signal processing circuit 11 to the second signal processing circuit 13, and It is input to the control section 10 as an output digital signal via the first A/D converter 12 to the second A/D converter 14 . In this pressing state, the protrusion height of the first pressing member 3 from the upper surface of the substrate 2 is higher than the protrusion height of the second pressing member 4 from the upper surface of the substrate 2. The reaction force _FB that the first pressing member 3 receives from the human body is greater than the reaction force _FD that the pair of second pressing members 4 receives from the human body. Therefore, the control unit 10 can detect the contraction of the target muscle based on the difference or the change in the ratio between the reaction force _FB and the reaction force _FD that are input as the output digital signal.

In this embodiment, in order to more accurately detect muscle contraction, the control unit 10 controls the reaction force _FB that the first pressing member 3 receives from the human body and the pair of second pressing members 4 from the human body. The sum FT with the received reaction force _FD is calculated, and the value obtained _by dividing the reaction force _FB by the sum _FT is used as the parameter value S of the degree of muscle contraction to detect muscle contraction. Formula (1), which is a formula for calculating the parameter value S, is shown below. The parameter value S is a dimensionless variable that ranges from 0 to 1.

The control unit 10 calculates the parameter value S in the state shown in FIG. 3, and detects muscle contraction based on changes in the parameter value S based on this. Here, the parameter value S is a value that changes based on the change in the ratio between the reaction force _FB received by the first pressing member 3 and the reaction force _FD received by the pair of second pressing members 4. Detecting muscle contraction based on changes in the parameter value S is based on changes in the ratio between the reaction force F _B received by the first pressing member 3 and the reaction force F _D received by the pair of second pressing members 4 . Equivalent to detecting muscle contraction based on Note that the control unit 10 is configured to detect muscle contraction based on a change in the ratio of the reaction force F _B received by the first pressing member 3 and the reaction force F _D received by the pair of second pressing members 4 . However, it is also possible to detect muscle contraction based on a change in the difference between the reaction force F _B received by the first pressing member 3 and the reaction force F _D received by the pair of second pressing members 4 . .

As the muscles gradually contract and harden from the state shown in FIG. As it moves, it gradually separates from the pair of second pressing members 4 . Therefore, the ratio of the reaction force _FB to the sum _FT gradually increases as the muscles contract, and the ratio of the reaction force _FD decreases gradually. That is, the parameter value S gradually increases to the reference value as the muscle contracts.

Then, as shown in FIG. 4, when the muscles contract further, the skin SK strongly contacts the first pressing member 3 while elastically deforming it, and weakly contacts the pair of second pressing members 4. In this state, the parameter value S becomes a value close to 1, and when the muscles contract further, the skin SK contacts only the first pressing member 3 and the parameter value S becomes 1. Thus, the parameter value S increases from the reference value to 1 as the muscle contracts. Therefore, the control unit 10 can detect contraction of the muscle from the increase in the parameter value S, and detect (measure) the degree of contraction of the muscle, that is, the amount of muscle activity from the parameter value S at that time. can also

Conversely, when the muscle relaxes and the contraction is canceled from the state shown in _{FIG .} descend. Therefore, the control unit 10 can detect that the muscles are relaxed from the decrease in the parameter value S, and also detect (measure) the degree of muscle contraction, that is, the amount of muscle activity from the parameter value S at that time. can also

The parameter value S can also be set, for example, to S= _FD /( _FB + _FD )= _FD / _FT . In this case, since the parameter value S gradually decreases as the muscle contracts, the control unit 10 can detect that the muscle contracts from the decrease in the parameter value S, and at the same time From the parameter value S, it is also possible to detect (measure) the degree of muscle contraction, that is, the amount of muscle activity.

As shown in FIGS. 1 and 2, the muscle contraction detection sensor 1 has a pair of flexible sheet-like electrodes 8 fixed to the surfaces of the pair of second pressing members 4 . The pair of electrodes 8 are composed of biomedical electrodes formed in a flexible sheet shape that can be deformed according to the deformation of the second pressing member 4 using, for example, conductive rubber. In this embodiment, the pair of electrodes 8 each have a rectangular sheet shape that is one size smaller than the second pressing member 4 in plan view, and one electrode 8 is the surface of the second pressing member 4 . The other electrode 8 is attached to (the surface facing away from the substrate 2) using an attaching means such as an adhesive or double-sided tape, and the other electrode 8 is attached to the surface of the other second pressing member 4 (the surface opposite to the substrate 2). is attached using an adhesive, double-sided tape, or other attachment means. The pair of electrodes 8 can be connected to an external device by wiring (not shown).

When the muscle contraction detection sensor 1 is attached to the human body and the first pressing member 3 and the pair of second pressing members 4 are pressed against a muscle part of the human body, the pair of electrodes 8 are connected to the corresponding muscle of the human body. By directly contacting the skin at the site, the pulse signal input from the external device, that is, the stimulation pulse, can be transmitted to the muscle or the motor nerve that controls the muscle, and the myoelectric potential signal generated when the muscle is activated. Can be sent to an external device.

The pair of electrodes 8 may be of various constructions or materials as long as they are in the form of a flexible sheet having electrical conductivity suitable for electrical stimulation and detection of myoelectric potential.

The muscle contraction detection sensor 1 having the above configuration can be used as a quantitative electrical stimulator having a muscle activity amount feedback function.

As shown in FIG. 5, when the muscle contraction detection sensor 1 is used as a quantitative electrical stimulation device, the first reaction force detection unit 6 and the second reaction force detection unit 7 are respectively controlled by a computer. connected to the unit 10;

In this embodiment, the first reaction force detection unit 6 includes a first signal processing circuit 11 that amplifies and outputs an output signal input from the first reaction force detection unit 6, and a first signal processing circuit 11 is connected to the control unit 10 via the first A/D converter 12 that converts the output amplified signal input from the first A/D converter 12 into a digital signal and outputs it, and the output signal of the first reaction force detection unit 6 is output It is input to the control unit 10 as a digital signal. Similarly, the second reaction force detection unit 7 amplifies and outputs the output signal input from the second reaction force detection unit 7, and inputs from the second signal processing circuit 13 is connected to the control unit 10 via a second A/D converter 14 which converts the amplified output signal into a digital signal and outputs it, and the output signal of the second reaction force detection unit 7 is an output digital signal is input to the control unit 10 as.

Moreover, as shown in FIG. 5, when the muscle contraction detection sensor 1 is used as a quantitative electrical stimulation device, the pair of electrodes 8 are connected to the pulse generator 15 respectively. In this embodiment, the pulse generator 15 amplifies the voltage and current so that the pulse signal output by the pulse generator 15 has the power required for electrical stimulation, and converts it into stimulation pulses via a signal processing circuit 16. It is connected to a pair of electrodes 8 . The pulse generator 15 can input stimulation pulses amplified by the signal processing circuit 16 to the pair of electrodes 8 as pulse signals. The pulse generator 15 is connected to the control section 10 and configured to output a pulse signal based on waveform information input from the control section 10 . The stimulation pulse can be set, for example, to have a stimulation time of 2 seconds to stimulate the muscles and a rest time of 3 seconds to rest the muscles. The control unit 10 can adjust the intensity (voltage) of the pulse signal or stimulation pulse output from the pulse generator 15 .

Next, the operation of the muscle contraction detection sensor 1 having the above configuration as a quantitative electrical stimulation device will be described.

First, as shown in FIG. 3, the muscle contraction detection sensor 1 is attached to a predetermined portion such as an arm of a human body using a fixing device (not shown) such as an elastic belt, as described above, and a pair of electrodes 8 are attached. Attached in direct contact with the skin SK.

Next, waveform information is input from the control section 10 to the pulse generator 15 , and pulse signals are output from the pulse generator 15 toward the pair of electrodes 8 . When the pulse signal output from the pulse generator 15 is amplified by the signal processing circuit 16 and converted into a stimulating pulse and input to the pair of electrodes 8, the stimulating pulse of the pair of electrodes 8 is applied to the muscle or the movement that governs the muscle. When applied to a nerve, the muscle or the motor nerve controlling the muscle is electrically stimulated, causing the muscle to contract. At this time, the amount of muscle contraction, that is, the amount of muscle activity changes according to the intensity of the stimulation pulse applied from the pair of electrodes 8 to the muscle or motor nerve. The control unit 10 operates the pulse generator 15, i.e., controls the stimulation pulses applied to the muscles from the pair of electrodes 8 so that the amount of muscle activity reaches a predetermined target value (for example, 50% of the maximum voluntary contraction). Adjust intensity.

When stimulation pulses are applied from the pair of electrodes 8 and the muscles contract, the control unit 10 detects the reaction force received by the first pressing member 3 detected by the first reaction force detection unit 6 by the method described above. and the reaction force received by the pair of second pressing members 4 detected by the second reaction force detection unit 7 or a change in the ratio thereof, a stimulation pulse is input from the pair of electrodes 8 to contract the muscle measure the amount of muscle activity in the

Then, based on the detected amount of muscle activity, the control unit 10 operates the pulse generator 15, i.e., the intensity of the stimulation pulse input to the pair of electrodes 8, so that the amount of muscle activity reaches a predetermined target value set in advance. the feedback control. For example, when electrical stimulation is continuously applied to muscles, the amount of muscle activity gradually attenuates due to muscle fatigue. The amount of muscle activity detected based on the change in the difference or ratio between the reaction force received by the pair of second pressing members 4 and detected by the reaction force detection unit 7 is lower than the target value. The unit 10 controls the operation of the pulse generator 15 so as to increase the intensity (voltage) of the stimulation pulse so that the muscle activity level is maintained at the target value. On the other hand, the reaction force received by the first pressing member 3 detected by the first reaction force detection unit 6 and the reaction force received by the pair of second pressing members 4 detected by the second reaction force detection unit 7 are When the amount of muscle activity detected based on the change in the difference or the ratio of . Control the operation of the pulse generator 15 to dampen it. As a result, muscle activity can be generated quantitatively in the muscle so that the muscle activity amount reaches a predetermined target value.

Conventionally, the amount of muscle activity was generally detected or measured using an electromyograph. However, since the myoelectric potential is buried in the stimulation pulse under electrical stimulation, it is difficult to detect (measure) the amount of muscle activity of the electrically stimulated muscle using an electromyogram while performing electrical stimulation of the muscle. there were. In addition, the amount of muscle activity caused by electrical stimulation varies greatly depending on the skin condition and amount of subcutaneous fat. Since the amount of muscle activity changes depending on the intensity and the presence or absence of perspiration, it was difficult to set the intensity of the stimulation pulse and induce muscle activity quantitatively without feedback on the amount of muscle activity.

On the other hand, the muscle contraction detection sensor 1 of the present embodiment acts on at least two pressing members (in this embodiment, one first pressing member 3 and a pair of second pressing members 4) due to muscle contraction. Since the amount of muscle activity of the muscle is detected based on the physical change that occurs (change in muscle hardness accompanying muscle contraction), electrical stimulation and stimulation of the muscle can be performed without affecting myoelectric potential. , and detection (measurement) of the amount of muscle activity of the electrically stimulated muscle. Therefore, as a configuration in which the intensity of stimulation pulses is controlled by feeding back the amount of detected muscle activity, it is possible to provide quantitative electrical stimulation to muscles, highly reproducible electrical stimulation, and electrical stimulation that is not affected by fatigue.

Further, in the muscle contraction detection sensor 1 of the present embodiment, the pair of electrodes 8 for performing electrical stimulation are connected to pressing members (in this embodiment, a pair of second pressing members) for detecting or measuring the amount of muscle activity. 4), a pair of electrodes 8 for electrical stimulation and a pressing member for detecting or measuring muscle activity (in this embodiment, one Both the first pressing member 3 and the pair of second pressing members 4) can be applied to the muscle in question. Therefore, it is possible to apply the muscle contraction detection sensor 1 of the present embodiment to muscles in more parts. Furthermore, a pair of electrodes 8 for electrical stimulation are fixed and integrated on the surfaces of the pressing members (in this embodiment, the pair of second pressing members 4) for detecting or measuring the amount of muscle activity. Therefore, the muscle contraction detection sensor 1 can be more easily attached to a predetermined part of the human body, making it easier to use. can do.

Furthermore, in the muscle contraction detection sensor 1 of the present embodiment, the pair of electrodes 8 for performing electrical stimulation are connected to pressing members (in this embodiment, a pair of second pressing members) for detecting or measuring the amount of muscle activity. By fixing to the surface of 4), the position for applying electrical stimulation to the muscle and the position for detecting or measuring the amount of activity of the muscle can be brought close to each other. As a result, the amount of muscle activity can be fed back more accurately, and electrical stimulation can be performed more accurately and quantitatively to the muscles.

Furthermore, in the muscle contraction detection sensor 1 of the present embodiment, the pair of second pressing members 4 whose inner spaces 4a are connected to each other by the connecting channel 5 and the pair of second pressing members 4 are arranged between the pair of pressing members 4 One electrode 8 is fixed to the surface of one second pressing member 4 and the other electrode 8 is fixed to the surface of the other second pressing member 4 With such a configuration, the position for applying electrical stimulation to the muscle and the position for detecting or measuring the amount of activity of the muscle are brought closer to each other, so that the muscle can be subjected to more accurate and quantitative electrical stimulation.

Furthermore, in the muscle contraction detection sensor 1 of the present embodiment, the projection height of the first pressing member 3 from the substrate 2 in the no-load state is equal to the projection height of the second pressing member 4 from the substrate 2 in the no-load state. Since it is configured to be higher than the height, the reaction force that the second pressing member 4 receives from the skin SK can be made smaller than the reaction force that the first pressing member 3 receives from the skin SK with a simple configuration. Thereby, the configuration of the muscle contraction detection sensor 1 can be simplified, and the cost can be reduced.

The muscle contraction detection sensor 1 having the above configuration can also be used as a muscle fatigue measuring device.

As shown in FIG. 6, when the muscle contraction detection sensor 1 is used as a muscle fatigue measuring device, the first reaction force detection unit 6 and the second reaction force detection unit 7 are the same as in the case shown in FIG. , are connected to a control unit 10 each composed of a computer.

That is, the first reaction force detection unit 6 receives input from a first signal processing circuit 11 that amplifies and outputs an output signal input from the first reaction force detection unit 6, and the first signal processing circuit 11. is connected to the control unit 10 via a first A/D converter 12 that converts the amplified output signal into a digital signal and outputs it, and the output signal of the first reaction force detection unit 6 is an output digital signal. It is input to the control unit 10 . Similarly, the second reaction force detection unit 7 amplifies and outputs the output signal input from the second reaction force detection unit 7, and inputs from the second signal processing circuit 13 is connected to the control unit 10 via a second A/D converter 14 which converts the amplified output signal into a digital signal and outputs it, and the output signal of the second reaction force detection unit 7 is an output digital signal is input to the control unit 10 as.

Further, as shown in FIG. 6, when the muscle contraction detection sensor 1 is used as a muscle fatigue measuring device, the pair of electrodes 8 are connected to the controller 10 respectively. In this embodiment, the pair of electrodes 8 are connected to a signal processing circuit 17 that amplifies and outputs myopotential signals detected by the electrodes 8, and converts the amplified myopotential signals output from the signal processing circuit 17 into digital signals. and an A/D converter 18 for outputting through an A/D converter 18, and myopotential signals detected by the pair of electrodes 8 are input to the control unit 10 as myopotential digital signals.

Next, a method of using the muscle contraction detection sensor 1 having the above configuration as a muscle fatigue measuring device will be described.

When the muscle contraction detection sensor 1 is used as a muscle fatigue measuring device, as shown in FIG. A pair of electrodes 8 are used as electrodes for myoelectric potential measurement in a state in which a pair of electrodes 8 are attached to a predetermined site such as an arm of a human body so as to be in direct contact with the skin SK. That is, when the muscle contraction detection sensor 1 is used as a muscle fatigue measuring device, the control unit 10 detects the reaction force received by the first pressing member 3 detected by the first reaction force detection unit 6 and the second The amount of muscle activity of the contracting muscle is detected or measured based on the difference or ratio change from the reaction force received by the second pressing member 4 detected by the reaction force detection unit 7, and at the same time as the measurement, a pair of Based on the myoelectric potential or myoelectric potential digital signal input from the electrode 8, the amount of muscle activity of the contracting muscle is detected or measured. In this way, the muscle contraction detection sensor 1 detects or measures the amount of muscle contraction by at least two pressing members (in this embodiment, one first pressing member 3 and a pair of second pressing members 4). and myoelectric potential by the electrodes 8 are measured simultaneously. Then, the control unit 10 detects muscle fatigue based on the difference between these detected values or measured values.

When the same load is continuously applied to the muscle and the amount of muscle contraction and myoelectric potential are continuously measured during that period, the amplitude (voltage) of the myoelectric potential gradually increases even if the muscle exerted force remains the same. This is because when a muscle fatigues, more muscle fibers are recruited to maintain the same force. On the other hand, the amount of muscle contraction physically detected by at least two pressing members (in this embodiment, one first pressing member 3 and a pair of second pressing members 4) has the same muscle exertion force. If so, it will continue to be the same value regardless of fatigue. Therefore, at least two pressing members (in this embodiment, one first pressing member 3 and a pair of second pressing members 4) detect or measure the amount of muscle contraction and the pair of electrodes 8 The current fatigue level of the muscle can be obtained by making the detected value or the measured value dimensionless (converted to 100%) with the value at the time of maximal muscle exertion and taking the difference. Based on the method, the control unit 10 detects or measures the amount of muscle contraction by at least two pressing members (in this embodiment, one first pressing member 3 and a pair of second pressing members 4). and the detected or measured value detected by the pair of electrodes 8, the current degree of muscle fatigue is detected.

In this way, muscle fatigue can be measured easily and accurately by using the muscle contraction detection sensor 1 as a muscle fatigue measuring device. Further, by using the muscle contraction detection sensor 1 as a muscle fatigue measuring device, the muscle fatigue measuring device can be made simple and low cost.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

For example, in the above embodiment, by arranging the first pressing member 3 on the stepped portion 2a provided on the substrate 2, the protrusion height of the first pressing member 3 from the upper surface of the substrate 2 in the no-load state is reduced to However, as shown in FIG. Assuming that the shape is larger in the vertical direction than the second pressing member 4, the projection height of the first pressing member 3 from the upper surface of the substrate 2 in the no-load state is equal to that of the second pressing member 4 from the upper surface of the substrate 2. You may make it higher than the projection height from.

Further, in the above-described embodiment, the muscle contraction detection sensor 1 is used as a pressing member, and the pair of second pressing members 4 whose internal spaces 4a are connected to each other by the connection flow path 5 and the pair of second pressing members 4 Although it is configured to have one first pressing member 3 disposed between, it is not limited to this, for example, as shown in FIG. A configuration including a pair of connected first pressing members 3 and one second pressing member 4 arranged between the pair of first pressing members 3 can also be used. In this case, electrodes 8 are fixed to the surfaces of the pair of first pressing members 3, respectively.

Furthermore, in the above embodiment, the projection height of the first pressing member 3 from the upper surface of the substrate 2 in the no-load state is higher than the projection height of the second pressing member 4 from the upper surface of the substrate 2 in the no-load state. By increasing the height, the pressure that the first pressing member 3 receives from the human body in the pressing state in which it is pressed against the contracting muscle is greater than the pressure that the second pressing member 4 receives from the human body. However, the present invention is not limited to this. For example, the first pressing member 3 may be configured to have a higher elastic or repulsive force than the second pressing member 4 (for example, a configuration in which the first pressing member 3 is formed in a projection shape from a soft material such as silicon). As a result, the reaction force received by the first pressing member 3 from the human body in the state of being pressed against the muscles is equal to the reaction force received by the second pressing member 4 from the human body, regardless of the protrusion height in the unloaded state. It may be configured to be larger than In this case, even if the protrusion height of the first pressing member 3 from the upper surface of the substrate 2 in the no-load state is the same as the protrusion height of the second pressing member 4 from the upper surface of the substrate 2 in the no-load state. It can be very different.

Furthermore, in the above-described embodiment, only one second reaction force detection unit 7 is provided for the pair of second pressing members 4, but the present invention is not limited to this, and the second pressing members 4 can be detected more accurately. A pair of second reaction force detectors 7 corresponding to each of the second pressing members 4 are provided in order to detect the reaction force applied to the A configuration may be adopted in which the average value is employed as the reaction force applied to the second pressing member 4 .

REFERENCE SIGNS LIST 1 muscle contraction detection sensor 2 substrate 2a stepped portion 3 first pressing member 3a internal space 4 second pressing member 4a internal space 5 connecting channel 6 first reaction force detection portion 6a pressure detection surface 7 second reaction force Detection unit 7a Pressure sensing surface 8 Electrode 10 Control unit 11 First signal processing circuit 12 First A/D converter 13 Second signal processing circuit 14 Second A/D converter 15 Pulse generator 16 Signal processing circuit 17 signal processing circuit 18 A/D converter _FB reaction force _FD reaction force _FT sum S parameter value SK skin

Claims (6)

a substrate arranged opposite to the muscle to be detected;
at least two pressing members arranged on the substrate and pressed against the muscle and receiving different reaction forces from each other;
at least two reaction force detection units that detect the reaction force received by the corresponding pressing members,
the pressing member includes a first pressing member and a second pressing member that receives a smaller reaction force from pressing the muscle when the muscle contracts than the first pressing member;
The reaction force detection unit includes a first reaction force detection unit that detects a reaction force received by the first pressing member, and a second reaction force detection unit that detects a reaction force received by the second pressing member. , including
difference or ratio between the reaction force received by the first pressing member detected by the first reaction force detection unit and the reaction force received by the second pressing member detected by the second reaction force detection unit A muscle contraction detection sensor that detects muscle contraction based on a change in
A muscle contraction detection sensor, further comprising a pair of flexible sheet-like electrodes each fixed to a surface of said pressing member. a pulse generator for inputting a pulse signal to the pair of electrodes;
When a pulse signal is input from the pulse generator to the pair of electrodes, the reaction force received by the first pressing member detected by the first reaction force detection section and the reaction force received by the second reaction force detection section a control unit that feedback-controls the operation of the pulse generator based on the amount of muscle contraction detected based on a change in the detected difference or ratio with respect to the reaction force received by the second pressing member. The muscle contraction detection sensor according to claim 1. The myoelectric potential of the muscle detected by the pair of electrodes, the reaction force received by the first pressing member detected by the first reaction force detection unit, and the reaction force detected by the second reaction force detection unit 2. The fatigue measurement unit according to claim 1, further comprising a fatigue measurement unit that measures the fatigue of the muscle from the difference from the reaction force received by the second pressing member or the difference from the muscle contraction amount detected based on the change in ratio. muscle contraction detection sensor. The muscle contraction detection sensor according to any one of claims 1 to 3, wherein said first pressing member and said second pressing member are each formed in the shape of a flexible bag containing a fluid therein. a pair of said second pressing members whose inner spaces are connected to each other by a connecting channel; and one said first pressing member disposed between said pair of said second pressing members;
5. The muscle contraction detection sensor according to claim 4, wherein one of the electrodes is fixed to the surface of one of the second pressing members, and the other of the electrodes is fixed to the surface of the other of the second pressing members. . 6. Any one of claims 1 to 5, wherein a projection height of said first pressing member from said substrate in an unloaded state is higher than a projection height of said second pressing member from said substrate in an unloaded state. The muscle contraction detection sensor according to the item.

Images