Muscle fatigue measurement device, muscle fatigue measurement method, muscle fatigue measurement program

Abstract

To provide a muscle fatigue measurement device achieving both of avoidance of an influence of muscle shape changes and improvement of a wearing property.SOLUTION: A muscle fatigue degree measurement device 10 includes a displacement measurement part 14 as well as a BI measurement unit 12. The BI changes not only due to muscle fatigue, but also due to changes in an elbow angle. It can be seen that compared to an elbow angle of 180 degrees, |Z| decreases at an elbow angle of 90 degrees even before the same fatigue. Specifically, when muscle fatigue is measured by the BI measurement part 12, a change in the joint angle causes an error, so that the muscle fatigue degree measurement device 10 employs both the BI measurement part 12 and the displacement measurement part 14 in order to eliminate (offset) the error. A base material is a rectangular and flexible adhesive tape 32 for fixing on an upper arm part 16. As the adhesive tape 32 is thinner, it is better, however, a material, thinness, etc. may be chosen depending on balance with strength (strong enough not to break when bending and straightening the elbow).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a muscle fatigue degree measuring device, a muscle fatigue degree measuring method, and a muscle fatigue degree measuring program.

Background Art

[0002] Non-Patent Document 1 describes measuring the bioelectrical impedance (BI) of the arm by the four-electrode method and evaluating the fatigue degree of the muscle from the change in impedance.

[0003] Patent Document 1 describes that simultaneously with the measurement of BI, the length (site length Ml) and width (site width Mw) between electrodes at the measurement site are measured, the effective length of the muscle tissue is calculated from these values, a bioequivalent model is calculated from BI and the effective length, and muscle fatigue is evaluated.

[0004] Bioelectrical impedance changes with the increase or decrease in the amount of blood in the muscle during muscle fatigue and the distortion of the muscle shape during joint angle change. For example, the bioelectrical impedance of the upper arm decreases due to fatigue, but also decreases due to the flexion of the elbow joint. Therefore, when evaluating the degree of fatigue from bioelectrical impedance using the method of Patent Document 1, it is necessary to exclude the influence of the change in muscle thickness accompanying the change in joint angle. By using the technique of Patent Document 2 (correcting BI using the effective length of the muscle), the influence of the change in muscle shape can be avoided.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

[0007] However, conventional measuring devices, including Non-Patent Document 1, lack flexibility in response to changes in joint angle (for example, bending and straightening the arm), resulting in poor fit (difficulty bending and straightening the arm, etc.).

[0008] Considering the above facts, the present invention aims to provide a muscle fatigue measurement device, a muscle fatigue measurement method, and a muscle fatigue measurement program that can simultaneously avoid the effects of changes in muscle shape and improve wearing comfort. [Means for solving the problem]

[0009] The muscle fatigue measurement device according to the present invention includes an electrical impedance measurement unit that measures the electrical impedance of a specific part of a living body, a joint angle measurement unit that measures the angle of a joint that causes the muscle of the specific part of the living body to contract, and, before exercise of the specific part, The joint angle was measured by the aforementioned joint angle measuring unit. Pre-movement joint angle and , measured by the electrical impedance measurement unit A storage unit that stores pre-motion characteristic data showing the relationship with pre-motion electrical impedance, The pre-movement joint angle and the pre-movement electrical impedance are stored in the memory unit before execution. During the movement of the aforementioned specific body part, Joint angle during movement and the An acquisition unit that acquires in-movement characteristic data, including in-movement electrical impedance corresponding to joint angle during movement, as measured values ​​of muscle fatigue in the specified area, From the pre-movement characteristic data stored in the memory unit, the pre-movement electrical impedance corresponding to the pre-movement joint angle equivalent to the measured joint angle during movement is read out, and the read-out pre-movement electrical impedance is subtracted from the electrical impedance during movement, which is measured and obtained at the same timing as the measured joint angle during movement, to correct it. It has a correction unit, The motion characteristic data includes a plurality of joint angles during motion and a plurality of electrical impedances during motion, each corresponding to each of the plurality of joint angles during motion, and the correction unit is characterized by performing a correction on each of the plurality of electrical impedances during motion using the pre-motion electrical impedance corresponding to the pre-motion joint angle corresponding to each of the plurality of joint angles during motion. They are doing it.

[0010] According to the present invention, the memory unit stores pre-movement characteristic data showing the relationship between the pre-movement joint angle and the pre-movement electrical impedance at a specific body part before movement of that body part. The acquisition unit acquires in-movement characteristic data, including the joint angle measured by the joint angle measurement unit and the electrical impedance during movement corresponding to the joint angle measured by the electrical impedance measurement unit, during movement of a specific body part, as an actual measured value of muscle fatigue in that body part.

[0011] Since these measured values ​​include changes in electrical impedance due to angular displacement of joints that contract muscles in specific parts of the body, the correction unit corrects the in-movement characteristic data acquired by the acquisition unit based on the pre-movement characteristic data.

[0012] This makes it possible to avoid the effects of changes in muscle shape while simultaneously improving the fit and comfort.

[0014] As part of the correction by the correction unit, the pre-movement electrical impedance corresponding to the pre-movement joint angle equivalent to the measured joint angle during movement is read from the pre-movement characteristic data stored in the memory unit, and the correction is performed by subtracting the read-out pre-movement electrical impedance from the electrical impedance during movement measured at the same timing as the measured joint angle during movement. This difference becomes the electrical impedance corresponding to the actual muscle fatigue.

[0016] In the present invention, the pre-exercise characteristic data is obtained before the start of movement of a specific part of the living body using the electrical impedance measurement unit and the joint angle measurement unit. Luck In the absence of a dynamic load, The relationship This data is characterized by being a measurement of the electrical impedance of each nodal angle.

[0017] By measuring the electrical impedance at predetermined joint angles before each exercise session, while the body is not under any exercise load, the accuracy of pre-exercise electrical impedance based on the body's state can be maximized.

[0018] In the present invention, it is characterized in that the pre-exercise characteristic data is pre-databaseized as existing data for each specific part of the living body based on an identification code.

[0019] For versatility and convenience, it is preferable to pre-databaseize the pre-exercise characteristic data as existing data for each specific part of the living body based on an identification code.

[0020] In the present invention, the specific part of the living body is the upper arm, and the joint part is the elbow ri, luck The movement is a repetitive movement of bending and extending the elbow in a state of gripping a dumbbell as a load, which is characterized.

[0021] Particularly, in the bending and extending of the elbow of the upper arm, the change in the skin stretch and cross-sectional area of the part where the electrical impedance is measured is large.

[0022] This makes the pre-exercise characteristic data a useful parameter for improving accuracy.

[0023] The muscle fatigue degree measurement method according to the present invention is a muscle fatigue degree measurement method by a muscle fatigue degree measurement device including an electrical impedance measurement unit for measuring the electrical impedance of a specific part of the living body and a joint angle measurement unit for measuring the angle of a joint part that contracts the muscle of the specific part of the living body. Before the movement of the specific part, the pre-exercise characteristic data indicating the relationship between the pre-exercise joint angle and the pre-exercise electrical impedance at the specific part is stored, The joint angle was measured by the aforementioned joint angle measuring unit. pre-exercise joint angle and , measured by the electrical impedance measurement unit pre-exercise electrical impedance is stored, The pre-movement joint angle and the pre-movement electrical impedance are stored in the memory unit before execution. During the movement of the specific part, the in-movement characteristic data including the in-movement electrical impedance corresponding to the in-movement joint angle at the specific part is acquired as the actually measured value of the muscle fatigue degree of the specific part, The joint angle during the aforementioned movement and the which is characterized. From the stored pre-movement characteristic data, the pre-movement electrical impedance corresponding to the pre-movement joint angle equivalent to the measured joint angle during movement is read out, and the read-out pre-movement electrical impedance is subtracted from the electrical impedance during movement, which is measured and obtained at the same timing as the measured joint angle during movement, to correct it. 、 The motion characteristic data includes a plurality of joint angles during motion and a plurality of electrical impedances during motion, each corresponding to each of the plurality of joint angles during motion, and each of the plurality of electrical impedances during motion is corrected using a plurality of electrical impedances before motion, each corresponding to each of the plurality of joint angles before motion, each corresponding to each of the plurality of joint angles during motion. This is the feature.

[0024] The muscle fatigue level measurement program according to the present invention is characterized in that a computer is operated as the storage unit, acquisition unit, and correction unit of the muscle fatigue level measurement device described above. [Effects of the Invention]

[0025] As described above, the present invention makes it possible to avoid the effects of changes in muscle shape and to improve the wearing comfort at the same time. [Brief explanation of the drawing]

[0026] [Figure 1] (A) is a schematic diagram of the muscle fatigue level measuring device according to this embodiment, and (B) is a front view of the arm of a living person that is the subject of measurement. [Figure 2] (A) is a front view of the arm being measured, specifically for BI measurement; (B) is a characteristic diagram showing a comparison of BI values ​​before and after fatigue when the elbow angle of the upper arm is 90 degrees; and (C) is a characteristic diagram showing a comparison of BI values ​​before fatigue when the elbow angle is 90 degrees and 180 degrees. [Figure 3] (A) is a front view of the arm (elbow angle 180 degrees) specifically designed for measurement in the displacement measurement unit, (B) is a front view of the arm (elbow angle 90 degrees) specifically designed for measurement in the displacement measurement unit, and (C) is a schematic diagram of the displacement measurement unit. [Figure 4] (A) is a front view of the structure of the muscle fatigue measurement device according to this embodiment, (B) is a cross-sectional view of the IVB-IVB line in Figure 4(A), and (C) is a cross-sectional view of the IVC-IVC line in Figure 4(A). [Figure 5] These are displacement characteristic diagrams of the arm being measured; (A) is the elbow angle-measurement site length characteristic diagram, and (B) is the elbow angle-circumference characteristic diagram. [Figure 6] This is a characteristic graph of BI values ​​measured and stored before exercise, at elbow angles from 90 to 180 degrees. [Figure 7] This is a characteristic graph of BI values ​​before and during exercise, at elbow angles from 90 to 180 degrees. [Figure 8] This is a control flowchart for measuring fatigue levels according to this embodiment. [Figure 9]Figure 8 shows specific examples of measurement data based on fatigue level measurement, where (A) is a time-series transition characteristic diagram of BI value and elbow angle from before exercise to during exercise, (B) is a characteristic diagram of elbow angle-BI value before exercise, and (C) is a characteristic diagram of elbow angle-BI value during exercise. [Modes for carrying out the invention]

[0027] Figure 1 shows a muscle fatigue level measuring device 10 according to this embodiment.

[0028] The muscle fatigue level measuring device 10 consists of a bioelectrical impedance (BI) measuring unit 12 (hereinafter referred to as the BI measuring unit 12) and a displacement measuring unit 14 that measures the displacement of the measuring unit.

[0029] The muscle fatigue measurement device 10 is attached to the upper arm 16 of the human body and measures the degree of fatigue based on exercise (bending and straightening the elbow) using equipment such as dumbbells.

[0030] In this embodiment, when measuring with the BI measuring unit 12 shown in Figure 1, displacement measurement (mainly displacement caused by bending and straightening of the elbow) is performed simultaneously with this measurement by the displacement measuring unit 14, and the error in the BI measurement value (Z) corresponding to the amount of displacement is canceled out. Figure 1(A) shows the upper arm 16 with the elbow extended (elbow angle 180 degrees), and Figure 1(B) shows the elbow bent (elbow angle 90 degrees).

[0031] (Basis for using both the BI measurement unit 12 and the displacement measurement unit 14) Figure 2(A) shows the basic configuration of the BI measurement unit 12, which is the fundamental configuration of this embodiment. The BI measurement unit 12 is equipped with four electrodes (P1, P2, P3, P4), each having a pair of electrodes for current supply and a pair of electrodes for voltage measurement, and is attached linearly to the upper arm portion 16.

[0032] A current I [A] is wired between the two outer electrodes (P1 and P4). While current flows between electrodes P1 and P4, the voltage between the two inner electrodes (P2 and P3) is measured. The bioelectrical impedance BI Z [Ω] is calculated from the ratio of the current value to the voltage value.

[0033] The current I is selected from multiple sine waves of different frequencies, for example, 2kHz, 50kHz, and 200kHz sine waves, and its RMS value is, for example, 0.05mA.

[0034] Here, when muscles become fatigued through strength training (such as bending and straightening the elbows while holding dumbbells as described above), the blood volume within the muscles increases.

[0035] Because the resistance of blood is lower than that of other body tissues, the BI decreases as blood volume increases. Therefore, muscle fatigue can be measured by measuring the BI (see Figure 2(B)).

[0036] Figure 2(B) shows the BI measurement results obtained by the BI measurement unit 12 shown in Figure 2(A). Since Z is a complex number, it can be represented using a Cole-Cole plot with the real part on the horizontal axis and the imaginary part on the vertical axis. As shown in Figure 2(B), for example, |Z| at 50 kHz decreases after fatigue compared to before fatigue.

[0037] Incidentally, as shown in Figure 1, in this embodiment, the muscle fatigue level measuring device 10 is equipped with a displacement measuring unit 14 in addition to the BI measuring unit 12.

[0038] BI (Body Index) changes not only due to muscle fatigue, but also when the angle of the elbow changes.

[0039] Figure 2(C) shows the BI measurement results when the elbow angle is 180 degrees (elbow angle 180 degrees) and 90 degrees (elbow angle 90 degrees).

[0040] As shown in Figure 2(C), these are examples of measurement results for BI Z at elbow angles of 180 degrees and 90 degrees (both before fatigue).

[0041] The results in Figure 2(C) show that |Z| decreases at an elbow angle of 90 degrees compared to when the elbow angle is 180 degrees, even under the same pre-fatigue conditions.

[0042] In other words, when measuring muscle fatigue with the BI measurement unit 12, changes in joint angle become an error factor. Therefore, in order to eliminate (compensate for) this error, the muscle fatigue level measuring device 10 of this embodiment uses both the BI measurement unit 12 and the displacement measurement unit 14.

[0043] The detailed configurations of the BI measurement unit 12 and the displacement measurement unit 14 are described below.

[0044] (Configuration of BI measurement unit 12) As shown in Figure 1, the BI measurement unit 12 of this embodiment is equipped with four electrodes P1, P2, P3, and P4, similar to the basic configuration described above.

[0045] Each electrode P1, P2, P3, and P4 is attached linearly to the upper arm 16 of the human body. In addition, one end of the signal line 18 is electrically connected to each electrode P1, P2, P3, and P4, and the other end of the signal line is connected to the BI measurement unit 12.

[0046] As shown in Figure 2(A), the BI measurement unit 12 includes a power supply unit 12A that supplies a current of a predetermined frequency (sine wave) (e.g., RMS value: 0.05mA) between electrodes P1 and P4, and a voltmeter 12B that measures the voltage between electrodes P2 and P3. The frequency may be changed as appropriate or fixed.

[0047] Furthermore, the BI measurement unit 12 includes a calculation unit 12C. The calculation unit 12C calculates BI Z [Ω] from the ratio of the current value supplied by the power supply unit 12A and the voltage value measured by the voltmeter 12B.

[0048] The display unit 22 is connected to the BI measurement unit 12 via the processing unit 20.

[0049] The calculation results from the calculation unit 12C are displayed on the display unit 22 after predetermined processing by the processing unit 20. In addition to being displayed on the display unit 22, the calculation results may also be printed out on paper or communicated to a terminal device, or at least one of the other.

[0050] The details of the predetermined processing in the processing unit 20 will be described later, but the processing unit 20 includes a storage unit 20A that stores the θ-|Z| characteristic table before fatigue as storage data, and a calculation unit 20B that calculates (corrects) the difference between the storage data and the BI value input from the BI measurement unit 12 during exercise.

[0051] (Configuration of the displacement measuring unit 14) As shown in Figure 1, a displacement sensor 24 is connected to the displacement measuring unit 14, and this displacement sensor 24 is attached to the skin of the upper arm 16, adjacent to the BI measuring unit 12.

[0052] The details of the displacement measuring unit 14 will be described below with reference to Figure 3. In Figures 3(A) and (B), electrodes P1, P2, P3, and P4 (components of the BI measuring unit 12) attached to the upper arm 16 are not shown, but as shown in Figure 1, the displacement sensor 24 of the displacement measuring unit 14 and electrodes P1, P2, P3, and P4 are provided in parallel with each other.

[0053] In this embodiment, a so-called linear variable resistor type displacement sensor 24 is used as the displacement sensor 24 (see Figure 3(C)). The measured value from the displacement sensor 24 is sent to the displacement measuring unit 14. The displacement measuring unit 14 converts the measured value (amount of displacement) into an elbow angle and sends it to the processing unit 20.

[0054] The displacement sensor 24 is attached to the upper arm 16 and has the function of being able to deform flexibly even when the elbow is bent and straightened, which can be cited as one of the features of this embodiment. In other words, the displacement sensor 24 is not limited to the linear variable resistor type displacement sensor 24 applied in this embodiment.

[0055] For example, other than the linear variable resistor type displacement sensor 24, other displacement sensors that can be flexibly deformed even when the elbow is bent and straightened include strain gauge type sensors, wire displacement sensors, and capacitance displacement meters.

[0056] Figure 3 shows the detailed configuration of the linear variable resistor displacement sensor 24 used in this embodiment.

[0057] The displacement sensor 24 comprises a rectangular substrate 28 on which a strip-shaped conductor 26 is provided, and a bag 30 that houses the substrate 28.

[0058] The substrate 28 is partially housed in the bag 30, and its left end (shown at the outer end of Figure 3(C)) is fixed to the upper arm 16 (skin) via a fixing point 28A, and the right end of the bag 30 is fixed to the upper arm 16 (skin) via a fixing point 30A.

[0059] The bag body 30 is fitted with a push point 30B that is movable on the conductor 26.

[0060] Furthermore, the left end of conductor 26 is wired to terminal 1, and the right end of conductor 26 is grounded. The push-in point 30B is wired to terminal 2.

[0061] In the above configuration, the resistance between terminal 1 and terminal 2 changes as the indentation point 30B moves along the conductor 26.

[0062] Since the movement of the indentation point 30B depends on the relative movement between the substrate 28 and the bag body 30 due to the stretching and contracting of the skin of the upper arm 16 (bending and straightening of the elbow), the length of the measurement area can be determined by measuring the resistance value between terminals 1 and 2 of the displacement sensor 24.

[0063] Since this length correlates with the elbow angle, the elbow angle can be obtained from the measurement of the displacement sensor 24.

[0064] As an example of a product that can be used as the substrate 28 for the linear variable resistor type displacement sensor 24 applicable in this embodiment, "Spectrasymbol's SoftPot" can be mentioned.

[0065] (Implementation configuration of muscle fatigue level measuring device 10) Figure 4 shows the configuration for mounting the muscle fatigue level measuring device 10, specifically the BI measuring unit 12 and the displacement measuring unit 14, on the upper arm portion 16.

[0066] As shown in Figure 4(A), a rectangular, flexible adhesive tape 32 is used as the base material for fixing to the upper arm 16. The thinner the adhesive tape 32, the better, but the material and thickness should be selected in consideration of the balance with the strength (strength sufficient not to break when bending and straightening the elbow). Furthermore, a material that is gentle on the skin (does not cause rashes, etc.) is even more preferable.

[0067] Figure 4(B) is a cross-sectional view of the electrode portion of the BI measurement unit 12. Electrodes P1, P2, P3, and P4 each consist of an Ag / AgCl electrode 34 attached through the front and back surfaces of the adhesive tape 32, and a bioelectrode gel 36 positioned on the back side of the adhesive tape 32 (the side facing the upper arm portion 16). The Ag / AgCl electrode 34 and the bioelectrode gel 36 form pairs to constitute electrodes P1, P2, P3, and P4, respectively.

[0068] The Ag / AgCl electrode 34 is connected to the BI measurement unit 12 (see Figure 1(A)) via a signal line 18.

[0069] Furthermore, the bioelectrode gel 36 allows the Ag / AgCl electrode 34 to be electrically connected to the upper arm 16.

[0070] Figure 4(C) is a cross-sectional view of the displacement measuring unit 14, in which the substrate 28 is attached to the adhesive tape 32 via a fixed point 28A, and the bag body 30 is attached via a fixed point 30A. When the upper arm portion 16 is bent and straightened, the flexible adhesive tape 32 flexes, and the indentation point 30B moves along the conductor 26 of the displacement sensor 24.

[0071] (Verification of changes in BI value due to elbow flexion and extension) Figure 5(A) shows an example of the length (L1) of the measurement site at the displacement sensor 24 with respect to the elbow angle.

[0072] When the elbow angle is 180 degrees, L1 is 30 mm, but when the elbow angle is 90 degrees, the length (L1') is 25 mm.

[0073] Figure 5(B) shows an example of the circumference (L2) of the measurement site at the displacement sensor 24 with respect to the elbow angle.

[0074] When the elbow angle is 180 degrees, L2 is 255 mm, but when the elbow angle is 90 degrees, the circumference L2' is 263 mm.

[0075] From the above, we can estimate the change in impedance |Z|. Assuming that the resistivity within the measurement site is constant, and its magnitude is |ρ|, and the cross-sectional area of ​​the measurement site on the upper arm 16 is S, the impedance |Z| can be expressed by equation (1). |Z|=|ρ|×L1 / S···(1)

[0076] Here, assuming that the cross-section of the measurement site of the upper arm 16 is a perfect circle, the cross-sectional area S of the circumference L2 can be expressed by (2). S = L² × L² / (4π) ... (2)

[0077] From equations (1) and (2) above, |Z| can be expressed by (3). |Z|=4×π×|ρ|×L1 / (L2×L2)...(3)

[0078] Here, Figure 6 shows the |Z| with respect to the elbow angle when |ρ| = 9000 Ω mm.

[0079] As shown in Figure 6, when the elbow angle is 180 degrees, |Z| is 52.2 Ω, and when the elbow angle is 90 degrees, |Z| is 40.9 Ω.

[0080] Figure 7 shows an example of the BI value (|Z|Ω) of the elbow angle before and after fatigue. The BI value changes with the magnitude of fatigue and with elbow flexion.

[0081] Therefore, the processing unit 20 stores the θ-|Z| characteristic table before fatigue as memory data, as shown in Figure 6 (corresponding to the dashed line B in Figure 7).

[0082] The processing unit 20 calculates the difference between this stored data and the BI value input from the BI measurement unit 12 during exercise (see solid line A in Figure 7). This calculated value represents the fatigue level at any elbow angle, allowing for accurate evaluation of fatigue levels.

[0083] The operation of this embodiment will be described below.

[0084] Figure 8 is a control flowchart for measuring fatigue level according to this embodiment.

[0085] In step 100, the θ-|Z| characteristics before motion are measured, compiled into a table, and stored in the processing unit 20.

[0086] In the next step, 102, it is determined whether or not movement has started. If the determination in step 102 is positive, the process moves to step 104, where the θ-|Z| characteristics during movement are measured, and then to step 106.

[0087] In step 106, the θ-|Z| characteristic table stored in the processing unit 20 in step 100 is read, and the process proceeds to step 108.

[0088] In step 108, the difference ΔZ between the θ-|Z| characteristic during the movement and the θ-|Z| characteristic before the movement is calculated H. The process then proceeds to step 110, where the calculated ΔZ is displayed as the fatigue level, and this routine ends.

[0089] Figure 9 shows a specific example of measurement data based on the fatigue level measurement method shown in Figure 8.

[0090] First, before the exercise, move your elbow from 90 degrees to 180 degrees and memorize θ and |Z| (the pre-exercise range from the start of measurement to the first half of the timing chart in Figure 9(A)).

[0091] Figure 9(B) shows the memory results before the motion, which corresponds to the θ-|Z| characteristic table and is pre-stored in the processing unit 20.

[0092] Next, during exercise, the elbow angle θ and |Z| are measured continuously. These measurements are represented by the solid line shown by the circle in Figure 9(C).

[0093] From this solid line characteristic, the difference ΔZ between it and the data in the θ-|Z| characteristic table is calculated as the fatigue level (see Figure 9(C)). That is, as shown in Figure 9(B), the memory unit stores a characteristic table showing the relationship between the elbow angle before movement (e.g., 90 degrees, 135 degrees, 180 degrees) and the pre-movement impedance |Z| measured when the pre-movement elbow angle was measured. During movement, the elbow angle, which is the joint angle during movement, and the movement impedance |Z| are measured at the same time, and the pre-movement impedance |Z| corresponding to the pre-movement elbow angle of the same magnitude as the measured elbow angle during movement is read from the stored characteristic table. After reading, the read pre-movement electrical impedance is subtracted from the movement electrical impedance, and the difference ΔZ is calculated as the fatigue level. While it is possible to measure only one elbow angle during exercise and calculate a single difference ΔZ, as shown in Figures 9(A) and (B), it is also possible to measure multiple elbow angles during exercise (e.g., 90 degrees, 135 degrees, 180 degrees) and measure the in-exercise impedance |Z| at each timing of the measurement of multiple elbow angles. In this case, the pre-exercise impedance |Z| for each pre-exercise elbow angle of the same magnitude as each of the multiple in-exercise elbow angles measured is read from the stored characteristic table. After reading, for each elbow angle of the same magnitude, multiple difference ΔZ values ​​are calculated by subtracting the read pre-exercise electrical impedance from the in-exercise electrical impedance, and the average of the calculated differences may be used as the fatigue level.

[0094] In this embodiment, fatigue was measured during elbow flexion and extension, but this method can also be applied to measuring muscle fatigue during exercise of other specific body parts, such as knee flexion and extension (squats) while keeping the upper body vertical. In Figure 9, electrical impedance is measured before each exercise, but for example, a pre-exercise characteristics table may be created and stored in a database based on the identification number of the person performing the exercise, and then retrieved based on the identification number before exercise. It is preferable to update the database periodically or irregularly.

[0095] (Embodiment) The present invention may constitute embodiments of the dependent relationships shown in the following appendix. [Note 1] An electrical impedance measuring unit that measures the electrical impedance of a specific part of a living organism, A joint angle measuring unit that measures the angle of a joint that causes a muscle in a specific part of the living body to contract, A storage unit that stores pre-movement characteristic data showing the relationship between the pre-movement joint angle and pre-movement electrical impedance at the specified part before movement of that specific part, During movement of the specified body part, an acquisition unit acquires characteristic data during movement of the specified body part, including the joint angle during movement measured by the joint angle measurement unit and the electrical impedance during movement corresponding to the joint angle during movement measured by the electrical impedance measurement unit, as an actual measured value of muscle fatigue of the specified body part. A correction unit corrects the motion characteristic data acquired by the acquisition unit based on the pre-motion characteristic data, A muscle fatigue level measuring device having the following features.

[0096] [Note 2] The correction unit reads out the pre-motion electrical impedance corresponding to the pre-motion joint angle that corresponds to the measured joint angle during motion from the pre-motion characteristic data stored in the memory unit, The muscle fatigue measurement device described in Appendix 1, which corrects the measurement by subtracting the pre-exercise electrical impedance read out from the in-exercise electrical impedance measured at the same time as the joint angle measured during exercise.

[0097] [Note 3] The specified motion data includes a plurality of joint angles during motion and a plurality of electrical impedances during motion, each corresponding to each of the plurality of joint angles during motion. The muscle fatigue measurement device described in Appendix 2, wherein the correction unit corrects each of the multiple electrical impedances during movement using a plurality of pre-movement electrical impedances corresponding to each of the plurality of pre-movement joint angles, each corresponding to each of the plurality of joint angles during movement.

[0098] [Note 4] The aforementioned pre-motion characteristic data is A muscle fatigue level measuring device as described in any of the appendices 1 to 3, wherein, before the start of movement of a specific part of the living body, the electrical impedance measuring unit and the joint angle measuring unit are used to measure the electrical impedance of each predetermined joint angle in a state without the load of the movement, and the data is obtained.

[0099] [Note 5] The aforementioned pre-motion characteristic data is A muscle fatigue level measuring device described in one of the appendices 1 to 4, which is pre-databased as existing data for specific parts of the living body based on an identification code.

[0100] [Note 6] The specified part of the living body is the upper arm, and the joint is the elbow. The muscle fatigue measurement device described in any of the appendices 1 to 5, wherein the exercise is the repeated bending and straightening of the elbow while holding a dumbbell as a load.

[0101] [Note 7] A method for measuring muscle fatigue using a muscle fatigue measuring device comprising: an electrical impedance measuring unit for measuring the electrical impedance of a specific part of a living organism; and a joint angle measuring unit for measuring the angle of a joint that causes the muscle of the specific part of the living organism to contract; Before movement of the specified body part, pre-movement characteristic data showing the relationship between joint angle and electrical impedance at the specified body part is stored. During the movement of the specified body part, characteristic data during movement showing the relationship between the joint angle measured by the joint angle measuring unit and the electrical impedance measured by the electrical impedance measuring unit at the specified body part is acquired as the measured value of muscle fatigue at the specified body part. The acquired in-motion characteristic data is corrected based on the pre-motion characteristic data. Method for measuring muscle fatigue level.

[0102] [Note 8] Computers, The memory unit, acquisition unit, and correction unit of the muscle fatigue level measuring device described in any of the appendices 1 to 6 are to be operated as follows: A program for measuring muscle fatigue levels. [Explanation of symbols]

[0103] P1, P2, P3, P4 electrodes 10. Muscle fatigue level measuring device 12 BI Measurement Unit (Electrical Impedance Measurement Unit) 12A power supply section 12B Voltmeter 12C Arithmetic unit (acquisition unit) 14. Displacement measurement unit (joint angle measurement unit) 16. Upper arm 18 signal lines 20 Processing Units 20A storage unit (storage unit) 20B Calculation section (correction section) 22 Display section 24 Displacement Sensors 26 Conductors 28 circuit boards 28A fixed point 30 Bag body 30A fixed point 30B push point 32 Adhesive Tape 34 Ag / AgCl electrode 36 Bioelectrode Gel

Claims

1. An electrical impedance measuring unit that measures the electrical impedance of a specific part of a living organism, A joint angle measuring unit that measures the angle of a joint that causes a muscle in a specific part of the living body to contract, A storage unit stores pre-movement characteristic data showing the relationship between the pre-movement joint angle measured by the joint angle measuring unit and the pre-movement electrical impedance measured by the electrical impedance measuring unit at the specified part before movement of that specific part. An acquisition unit is performed after storing the pre-exercise joint angle and the pre-exercise electrical impedance in the storage unit, and during the movement of the specific body part, acquires in-exercise characteristic data, including the in-exercise joint angle and the in-exercise electrical impedance corresponding to the in-exercise joint angle, as an actual measured value of muscle fatigue of the specific body part. The system includes a correction unit that reads out the pre-movement electrical impedance corresponding to the pre-movement joint angle corresponding to the measured joint angle during movement from the pre-movement characteristic data stored in the memory unit, and corrects the electrical impedance during movement, which is measured and obtained at the same timing as the measured joint angle during movement, by subtracting the read-out pre-movement electrical impedance. The motion characteristic data includes a plurality of joint angles during motion and a plurality of electrical impedances during motion, each corresponding to each of the plurality of joint angles during motion. The correction unit is a muscle fatigue measurement device that corrects each of the multiple electrical impedances during movement using the pre-movement electrical impedance corresponding to the pre-movement joint angle which corresponds to each of the multiple joint angles during movement.

2. The pre-motion characteristic data is The muscle fatigue measurement device according to claim 1, wherein the electrical impedance measurement unit and the joint angle measurement unit are used to measure the electrical impedance of each predetermined joint angle in a state without exercise load, before the start of movement of a specific part of the living body.

3. The pre-motion characteristic data is The muscle fatigue level measuring device according to claim 1, wherein the data is pre-recorded in a database as existing data for specific parts of the living body based on an identification code.

4. The specific part of the living body is the upper arm, and the joint is the elbow, The muscle fatigue level measuring device according to claim 1, wherein the exercise is the repeated bending and straightening of the elbow while holding a dumbbell as a load.

5. A method for measuring muscle fatigue using a muscle fatigue measuring device comprising: an electrical impedance measuring unit for measuring the electrical impedance of a specific part of a living body; and a joint angle measuring unit for measuring the angle of a joint that causes the muscle of the specific part of the living body to contract, Before movement of the specified part, pre-movement characteristic data showing the relationship between the pre-movement joint angle measured by the joint angle measuring unit and the pre-movement electrical impedance measured by the electrical impedance measuring unit is stored. After storing the pre-movement joint angle and the pre-movement electrical impedance, the following is performed: During movement of the specific body part, characteristic data during movement, including the joint angle during movement and the electrical impedance during movement corresponding to the joint angle during movement, is acquired as the measured value of muscle fatigue in the specific body part. From the stored pre-movement characteristic data, the pre-movement electrical impedance corresponding to the pre-movement joint angle equivalent to the measured joint angle during movement is read out, and when correcting by subtracting the read-out pre-movement electrical impedance from the electrical impedance during movement, which is measured and obtained at the same timing as the measured joint angle during movement, The motion characteristic data includes a plurality of joint angles during motion and a plurality of electrical impedances during motion, each corresponding to each of the plurality of joint angles during motion, and corrections are made to each of the plurality of electrical impedances during motion using a plurality of pre-motion electrical impedances, each corresponding to each of the plurality of pre-motion joint angles, each corresponding to each of the plurality of joint angles during motion. Method for measuring muscle fatigue level.

6. A computer, The storage unit, acquisition unit, and correction unit of the muscle fatigue level measuring device according to any one of claims 1 to 4 are operated as follows: A program for measuring muscle fatigue levels.

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