Exercise support device, exercise support method, and exercise support program

Abstract

When causing a plurality of muscles to move in cooperation, the present invention makes it possible to determine a muscle to which an electrical stimulus should be presented and the presentation timing of the electrical stimulus. This exercise assistance device comprises a muscle synergy estimation unit, a stimulus site selection unit, and an electrical stimulus control unit. The muscle synergy estimation unit estimates, on the basis of information pertaining to the myoelectrical potential measured with regard to the plurality of muscles, the muscles that are moving in cooperation. The stimulus site selection unit selects, on the basis of the result of estimation by the muscle synergy estimation unit, a muscle at a stimulus-subject site to which an electrical stimulus should be presented. The electrical stimulus control unit controls the timing at which an electrical stimulus is presented to the muscle at the stimulus-subject site selected by the stimulus site selection unit.

Description

Technical Field

[0001] One aspect of the present invention relates to an exercise support device, an exercise support method, and an exercise support program.

Background Art

[0002] In motor learning, there is a system that conveys the knack of movement to a learner by moving the muscles of the learner using EMS (Electrical Muscle Stimulation), which is a technique of contracting muscles using electrical stimulation. For example, in Non-Patent Document 1, when playing the tremolo of the piano, by alternately presenting electrical stimulation to the extensor and flexor muscles of the learner's forearm, the learner is made to acquire a playing technique using the rotational movement of the wrist, and the knack of being able to play while relaxing is conveyed to the learner.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In exercises such as sports and musical instrument playing, multiple muscles may cooperate in movement. In order to support such exercises with EMS, it is necessary to determine which muscles should be presented with electrical stimulation and at what timing.

[0005] The present invention has been made paying attention to the above circumstances, and an object thereof is to provide an exercise support device, an exercise support method, and an exercise support program capable of determining a muscle to which electrical stimulation should be presented and the presentation timing thereof when causing a plurality of muscles to operate in cooperation.

Means for Solving the Problems

[0006] In order to solve the above problems, an exercise support device according to an aspect of the present invention includes a muscle synergy estimation unit, a stimulation site selection unit, and an electrical stimulation control unit. The muscle synergy estimation unit estimates muscles that are operating in cooperation based on information on myoelectric potentials measured for a plurality of muscles. The stimulation site selection unit selects a muscle at a stimulation target site to which electrical stimulation should be presented based on the estimation result of the muscle synergy estimation unit. The electrical stimulation control unit controls the presentation timing of electrical stimulation to the muscle at the stimulation target site selected by the stimulation site selection unit. The electrical stimulation control unit calculates the root mean square of samples with a certain window width for the electromyogram information of the muscles that cooperate with the muscles of the stimulation target site, and determines that the period during which the calculated root mean square exceeds a preset threshold is the presentation timing of electrical stimulation to the muscles of the stimulation target site.

Effects of the Invention

[0007] According to an aspect of the present invention, it is possible to provide an exercise support device, an exercise support method, and an exercise support program capable of determining a muscle to which electrical stimulation should be presented and the presentation timing thereof when causing a plurality of muscles to operate in cooperation.

Brief Description of the Drawings

[0008]

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[0009] Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

[0010] [First Embodiment] FIG. 1 is a schematic diagram showing an example of a learning system using the motion assistance device 10 according to the first embodiment of the present invention. This learning system is a learning system that conveys the knack of motion to a learner by moving the muscles of the learner using EMS.

[0011] As shown in FIG. 1, the motion assistance device 10 is connected to the electromyogram sensor 20 and the electrical stimulation device 30. A plurality of electrodes 40 for electromyogram measurement and electrical stimulation, which are attached to a learner who wants to learn a specific motion, are connected to each channel of the electromyogram sensor 20 and the electrical stimulation device 30. Each of the electrodes 40 for electromyogram measurement and electrical stimulation is attached to the learner corresponding to each part of the muscle to which electrical stimulation is to be presented. The electromyogram sensor 20 measures the electromyogram of the muscle part where the electrode 40 for electromyogram measurement and electrical stimulation is attached. The electrical stimulation device 30 presents electrical stimulation to the muscle part where it is attached by the electrode 40 for electromyogram measurement and electrical stimulation.

[0012] The exercise support device 10 performs muscle synergy analysis based on the values of the electromyogram of a plurality of muscles related to a specific exercise measured by the electromyogram sensor 20, estimates a muscle synergy indicating a combination of muscles that move in cooperation, and presents electrical stimulation by the electrical stimulation device 30 so that the muscles operate in cooperation with each other.

[0013] Muscle synergy indicates a coordinated pattern of a plurality of muscles. Muscle synergy can be estimated, for example, using the method disclosed in Yasunori Ozaki et al., "Characterizing muscular activities using non-negative matrix factorization from EMG channels for driver swings in golf", 2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), IEEE, 2016. This document proposes a method for estimating muscle synergy using non-negative matrix factorization (NMF) from the electromyogram of a plurality of muscles in sports.

[0014] By estimating muscle synergy, it is shown as the ratio (weighting coefficient) of the activity of each muscle in the spatial component of muscle synergy that specific muscles are operating in cooperation. For example, when measuring the electromyogram potentials of four types of muscles A, B, C, and D and performing NMF, assume that a total of two muscle synergies are extracted. At this time, in synergy 1, the weighting coefficients of muscle A and muscle B are "1", and in synergy 2, if the weighting coefficients of muscle C and muscle D are "1", it indicates that muscle A and muscle B operate in cooperation, and it also indicates that muscle C and muscle D operate in cooperation at a different timing. The number of synergies to be set is determined using an index called VAF (Variability accounted for). VAF is an index that compares the sum of squares of the data with the sum of squared errors between the data reconstructed by NMF and the original data, VAF = 1 - sum of squared errors / sum of squares of the data and is represented by this formula. The smaller the error, the closer VAF is to "1". In other words, when multiplying the matrices of the spatial component and the time component decomposed by NMF to reconstruct each electromyogram potential, the reproducibility can be obtained from the error with the original electromyogram potential. In general muscle synergy analysis, the minimum number of synergies for which this VAF exceeds a predetermined threshold (for example, "0.9") is the number of muscle synergies to be obtained.

[0015] Hereinafter, the motion assistance device 10 according to the first embodiment will be described in detail. FIG. 2 is a block diagram showing an example of the hardware configuration of the motion assistance device 10.

[0016] The motion assistance device 10 is composed of, for example, a PC (Personal Computer) or the like, and has a processor 11A such as a CPU (Central Processing Unit). The processor 11A may be a multi-core / multi-thread one and can execute a plurality of processes in parallel. And the motion assistance device 10 is configured such that a program memory 11B, a data memory 12, an input / output interface 13, and a communication interface 14 are connected to this processor 11A via a bus 15.

[0017] The program memory 11B uses, as a storage medium, a combination of a non-volatile memory such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive) that can be written to and read from at any time, and a non-volatile memory such as a ROM (Read Only Memory). The program memory 11B stores programs necessary for the processor 11A to execute various processes. The programs include an OS (Operating System) and various application programs, and as one of the application programs, include the exercise support program according to the first embodiment.

[0018] The data memory 12 is a storage that uses, as a storage medium, a combination of a non-volatile memory such as an HDD or an SSD that can be written to and read from at any time, and a volatile memory such as a RAM (Random Access Memory). The data memory 12 is used to store data acquired and created in the process of performing various processes.

[0019] The input / output interface 13 is an interface with an input device and an output device.

[0020] The input device includes the myoelectric sensor 20. Also, although not particularly shown, the input device includes a keyboard, a pointing device, etc. for the user to input instructions to the processor 11A. Further, the input device may include a reader for reading files and data to be stored in the data memory 12 from a memory medium such as a USB memory, and a disk device for reading such files and data from a disk medium.

[0021] The output device includes the electrical stimulation device 30. Also, although not particularly shown, the output device includes a display for displaying output data to be presented to the user from the processor 11A, a printer for printing it, etc. Further, the output device can include a speaker for outputting voice data and music data.

[0022] The communication interface 14 is a wired or wireless communication unit for connecting to a network such as a LAN (Local Area Network) or the Internet (not shown).

[0023] FIG. 3 is a block diagram showing the functional configuration of the motion assistance device 10 in association with the hardware configuration shown in FIG. 2.

[0024] The processing unit 11 is composed of the above-mentioned processor 11A and the above-mentioned program memory 11B, and as a software-based processing functional unit, it includes a myoelectric potential acquisition unit 111, a muscle synergy estimation unit 112, a stimulation site selection unit 113, an electrical stimulation control unit 114, and an electrical stimulation presentation unit 115. All of these processing functional units are realized by causing the processor 11A to execute a motion assistance program stored in the program memory 11B. The processing unit 11 may also be realized in other various forms including integrated circuits such as ASIC (Application Specific Integrated Circuit) and FPGA (field-programmable gate array).

[0025] In addition, the storage area of the non-volatile memory of the data memory 12 includes a target muscle synergy storage unit 121, and the storage area of the volatile memory of the data memory 12 includes a myoelectric potential storage unit 122, an estimated muscle synergy storage unit 123, and a stimulation site storage unit 124. Although not particularly shown, the storage area of the volatile memory of the data memory 12 further includes a temporary storage unit for temporarily storing various data generated during the processing operation of the processing unit 11.

[0026] The myoelectric potential acquisition unit 111 acquires the value of the myoelectric potential of a learner who is trying to learn a specific motion, input from the myoelectric sensor 20 via the input / output interface 13. The myoelectric potential acquisition unit 111 stores the acquired myoelectric potential value in the myoelectric potential storage unit 122 of the data memory 12.

[0027] The muscle synergy estimation unit 112 estimates a muscle synergy indicating a combination of muscles that move in cooperation by performing muscle synergy analysis using NMF from a plurality of myoelectric potential values stored in the myoelectric potential storage unit 122. The muscle synergy estimation unit 112 stores the estimation result in the estimated muscle synergy storage unit 123 of the data memory 12.

[0028] The target muscle synergy storage unit 121 of the data memory 12 stores a predetermined target muscle synergy in a non-volatile manner. The predetermined target muscle synergy is a muscle synergy estimated from myoelectric potential values measured from an expert for a specific movement to be learned by the learning subject.

[0029] The stimulation site selection unit 113 compares the spatial component of the estimated muscle synergy stored in the estimated muscle synergy storage unit 123 with the spatial component of the predetermined target muscle synergy stored in the target muscle synergy storage unit 121, and selects a stimulation target site to which an electrical stimulation is to be presented. The stimulation site selection unit 113 stores the selection result of the stimulation target site to which the electrical stimulation is to be presented in the stimulation site storage unit 124 of the data memory 12. Note that the stimulation target site to which the electrical stimulation is to be presented is not limited to one, and there may be a plurality of them.

[0030] The electrical stimulation control unit 114 controls the intensity and timing of the electrical stimulation to be presented for each of the selected stimulation target sites stored in the stimulation site storage unit 124. For example, the electrical stimulation control unit 114 controls the intensity of the electrical stimulation based on the predetermined target muscle synergy stored in the target muscle synergy storage unit 121 for the stimulation target site. Further, the electrical stimulation control unit 114 determines the timing at which the muscles that move in cooperation with the muscle to be stimulated by the electrical stimulation move based on the myoelectric potential values stored in the myoelectric potential storage unit 122, and controls the presentation timing of the electrical stimulation to the muscle to be stimulated. The electrical stimulation control unit 114 supplies a control signal indicating how much intensity and at what timing to present to which channel of the myoelectric measurement and electrical stimulation electrode 40 corresponding to the muscle to be stimulated, that is, to the electrical stimulation presentation unit 115.

[0031] The electrical stimulation presenting unit 115 outputs, at the timing when electrical stimulation should be presented, a drive signal based on the channels of the electromyogram measurement and electrical stimulation electrode 40 for presenting electrical stimulation and the intensity of the electrical stimulation, to the electrical stimulation device 30 via the input / output interface 13, in accordance with the control signal supplied from the electrical stimulation control unit 114. In response to this drive signal, the electrical stimulation device 30 presents electrical stimulation to the target muscle by means of the electromyogram measurement and electrical stimulation electrode 40 of the corresponding channel.

[0032] Note that the motion assistance device 10 according to the present embodiment can be realized by a processor 11A which is a computer and a motion assistance program stored in advance in a program memory 11B. However, it is also possible to record this motion assistance program on a non-transitory computer-readable medium or to provide it to the motion assistance device 10 through a network. The motion assistance program thus provided can be stored in the program memory 11B. Further, the provided motion assistance program can be stored in the data memory 12 which is a storage and executed by the processor 11A as needed, whereby the processor 11A can function as the processing unit 11.

[0033] Next, the processing operation of the motion assistance device 10 configured as described above will be described.

[0034] FIG. 4 is a flowchart showing the operation processing procedure of the motion assistance device 10 according to the first embodiment. The processor 11A of the motion assistance device 10 can perform the processing shown in this flowchart, for example, by executing a motion assistance program stored in advance in the program memory 11B.

[0035] The processor 11A first operates as the electromyogram acquisition unit 111, acquires the values of a plurality of electromyograms measured using the electromyogram sensor 20, and stores the acquired plurality of electromyogram values in the electromyogram storage unit 122 (step S1).

[0036] Subsequently, the processor 11A operates as a muscle synergy estimation unit 112, performs muscle synergy analysis on a plurality of myoelectric potential values stored in the myoelectric potential storage unit 122 using NMF, estimates a muscle synergy indicating a combination of muscles that move cooperatively, and stores the analysis result in the estimated muscle synergy storage unit 123 (step S2). In NMF, an n-row m-column matrix A (myoelectric data measured by the myoelectric sensors 20 of each channel) is decomposed into a non-negative factor matrix W (temporal component of muscle synergy, n rows k columns) and a matrix H (spatial component of muscle synergy, k rows m columns), and the root mean square error between A and W*H is minimized.

[0037] Then, the processor 11A operates as a stimulation site selection unit 113 and selects a target site to which electrical stimulation is to be presented as follows.

[0038] That is, the processor 11A first compares the spatial component of the estimated muscle synergy stored in the estimated muscle synergy storage unit 123 with the spatial component of the target muscle synergy stored in the target muscle synergy storage unit 121 (step S3). That is, the processor 11A compares each synergy in the above matrix H.

[0039] Then, as a result of this comparison, the processor 11A determines whether the weighting coefficient for a specific muscle is lower than the target value (step S4). That is, the processor 11A determines whether the weighting coefficient (each component of the matrix) for a specific muscle in each synergy in the above matrix H is lower than the target value.

[0040] If it is determined that the weighting coefficient of a specific muscle is lower than the target value, the processor 11A selects that specific muscle as a target site to which electrical stimulation is to be presented and stores it in the stimulation site storage unit 124 (step S5).

[0041] On the other hand, if it is determined in step S4 that the weighting coefficient of a specific muscle is not lower than the target value, the processor 11A further determines whether the weighting coefficient of that specific muscle is higher than the target value (step S6).

[0042] When it is determined that the weighting coefficient of a specific muscle is higher than the target value, the processor 11A selects, as a stimulation target site to which electrical stimulation is to be presented, the muscles that are cooperating other than the specific muscle, and stores them in the stimulation site storage unit 124 (step S7).

[0043] In this way, the stimulation target site to which electrical stimulation is to be presented is selected. The stimulation target site is not necessarily one.

[0044] In step S6 above, when it is determined that the weighting coefficient of a specific muscle is not higher than the target value, it means that the learner is performing the same movement as an expert. Therefore, in this case, since the processor 11A does not need to present electrical stimulation to the specific muscle, the processing operation ends.

[0045] If the stimulation target site is selected as described above, the processor 11A executes an electrical stimulation presentation processing subroutine to present electrical stimulation to each of the muscles that are the selected stimulation target sites (step S8). Then, the processor 11A ends the processing operation.

[0046] FIG. 5 is a flowchart showing details of the electrical stimulation presentation processing subroutine in step S8. In this electrical stimulation presentation processing subroutine, the processor 11A operates as the electrical stimulation control unit 114 to determine the intensity and timing of the electrical stimulation to be presented to the muscles of each stimulation target site, and operates as the electrical stimulation presentation unit 115 to present the electrical stimulation to each stimulation target site. Specifically, the processor 11A determines the intensity of the electrical stimulation based on the target muscle synergy, which is the muscle synergy estimated from the electromyogram values measured from an expert and stored in the target muscle synergy storage unit 121. That is, the processor 11A multiplies the matrices of the spatial component and the temporal component of the target muscle synergy decomposed by NMF to reconstruct the electromyogram values of each muscle, and obtains the electromyogram values of the muscles of the stimulation target site. Then, based on the obtained electromyogram values, the processor 11A calculates, for example, the intensity of the electrical stimulation to be presented to the muscles of the stimulation target site according to the difference between the obtained electromyogram values and the electromyogram values of the muscles of the stimulation target site stored in the electromyogram storage unit 122. In addition, the processor 11A synchronizes the presentation timing of the electrical stimulation with the timing at which the muscles that operate in cooperation with the muscles of the stimulation target site move.

[0047] As this synchronization method, in this first embodiment, the activity timing is estimated from the value of the electromyography sensor 20, and the electrical stimulation is presented through the electrical stimulation presentation unit 115.

[0048] For example, for each of the stimulation target sites, the processor 11A reads out electromyogram value samples of a certain window width (for example, 200 ms) from the time-series electromyogram values of the muscles that operate in cooperation with the muscles of the stimulation target site stored in the electromyogram storage unit 122 (step S81).

[0049] Then, for each read certain window width, the processor 11A calculates the root mean square (RMS) of the electromyogram value samples within that window width (step S82).

[0050] Next, the processor 11A determines whether the calculated RMS value exceeds a predetermined threshold (step S83). FIG. 6 is a diagram showing an example of time-series data of the RMS value of the electromyogram value of a certain muscle. In this example, the threshold is 40 μV.

[0051] And when it is determined that the RMS value exceeds the predetermined threshold, the processor 11A operates as the electrical stimulation presentation unit 115, outputs a drive signal to the electrical stimulation device 30 via the input / output interface 13, and presents an electrical stimulation to the muscle that is the selected stimulation target site (step S84). In the example of FIG. 6, when the processor 11A exceeds the threshold of 40 μV, it presents an electrical stimulation.

[0052] After that, or when it is determined in step S83 that the RMS value does not exceed the threshold, the processor 11A determines whether a specific movement that the learning subject learns has ended (step S85).

[0053] When it is determined that the specific movement to be learned has not ended yet, the processor 11A proceeds to the process of step S81 above.

[0054] And when it is determined that the specific movement to be learned has ended, the processor 11A ends the operation of this electrical stimulation presentation processing subroutine.

[0055] In this way, until the specific movement to be learned ends, for each selected stimulation target site, the processor 11A repeats presenting an electrical stimulation to the muscle of the stimulation target site in the section where the RMS value of the muscle that operates in cooperation with the muscle of the stimulation target site exceeds the threshold, which is 40 μV in the example of FIG. 6.

[0056] [Example] An example of a method for presenting electrical stimulation based on muscle synergy is shown below. When beginners and skilled players each performed a piano scale performance (a playing method of playing in order of "do, re, mi, fa, so, la, ti"), the electromyograms of five types of muscles (extensor digitorum communis, flexor digitorum superficialis, biceps brachii, triceps brachii, deltoid muscle) were measured. After the electromyogram measurement, muscle synergy analysis was performed using NMF. The implementation results were as shown in FIGS. 7 and 8.

[0057] Here, FIG. 7 is a diagram showing an example of the muscle synergy analysis result when a beginner performs a piano scale performance, and FIG. 8 is a diagram showing an example of the muscle synergy analysis result when a skilled player performs a scale performance. Comparing the muscle synergies of the two, there is no significant difference in "synergy 1". On the other hand, looking at "synergy 2", it can be seen that in beginners, the extensor digitorum communis and the flexor digitorum superficialis are coordinated, while in skilled players, the flexor digitorum superficialis and the deltoid muscle are coordinated and operate. From this difference, it can be said that beginners are always using the flexor digitorum superficialis to press the keyboard, while skilled players, at the same time as pressing the keyboard, use the deltoid muscle to abduct the arm to make it easier to slide the hand horizontally. This is considered to be particularly prominent in the finger-through movement (the movement of the thumb passing under the middle finger) during scale performance.

[0058] Therefore, in order to make the beginner's synergy 2 closer to that of a skilled player, electrical stimulation can be presented to the deltoid muscle at the timing when the flexor digitorum superficialis is active. Therefore, for a learning subject who is a beginner, the RMS is calculated from the electromyogram value of the flexor digitorum superficialis, which is a muscle that operates in coordination with the deltoid muscle, which is the muscle of the stimulation target site from the learning subject. If the value of the RMS exceeds a predetermined threshold, electrical stimulation is presented to the electrode 40 for electromyogram measurement and electrical stimulation corresponding to the deltoid muscle of the learning subject. Thereby, when the learning subject learns scale performance, the movement of the arm during finger-through can be assisted by electrical stimulation. That is, if the deltoid muscle of the learning subject is contracted by electrical stimulation at the moment when the flexor digitorum superficialis of the learning subject is active, the flexor digitorum superficialis and the deltoid muscle of the learning subject can be made to operate in coordination. As a result, when the learning subject presses the keyboard, the arm of the learning subject abducts at the same time, making it easier to perform the finger-through movement, and it becomes possible to perform a smooth scale performance like that of a skilled player.

[0059] As described in detail above, the motion assistance device 10 according to the first embodiment of the present invention includes a muscle synergy estimation unit 112 that estimates muscles that operate in cooperation based on information on myoelectric potentials measured for a plurality of muscles, a stimulation site selection unit 113 that selects a muscle of a stimulation target site to which an electrical stimulation is to be presented based on the estimation result of the muscle synergy estimation unit 112, and an electrical stimulation control unit 114 that controls the presentation timing of the electrical stimulation to the muscle of the stimulation target site selected by the stimulation site selection unit 113. Therefore, according to the motion assistance device 10 according to the first embodiment, it is possible to determine the muscle to which the electrical stimulation is to be presented and the presentation timing thereof when operating a plurality of muscles in cooperation. In this way, by determining the muscle and timing for presenting the electrical stimulation based on the estimation result of the muscles operating in cooperation, it is possible to assist the movement in which a plurality of muscles move in cooperation.

[0060] Further, the electrical stimulation control unit 114 determines the presentation timing of the electrical stimulation to the muscle of the stimulation target site by using information on myoelectric potentials of the muscles that operate in cooperation with the muscle of the stimulation target site. Therefore, according to the motion assistance device 10 according to the first embodiment, it is possible to determine the presentation timing of the electrical stimulation to the muscle of the stimulation target site without an external timing signal.

[0061] Here, the electrical stimulation control unit 114 calculates the root mean square of samples having a certain window width for the information on myoelectric potentials of the muscles that operate in cooperation with the muscle of the stimulation target site, and determines that the period during which the calculated root mean square exceeds a preset threshold value is the presentation timing of the electrical stimulation to the muscle of the stimulation target site. Therefore, according to the motion assistance device 10 according to the first embodiment, it is possible to determine the presentation timing of the electrical stimulation to the muscle of the stimulation target site based on the information on myoelectric potentials measured from the muscles that operate in cooperation with the muscle of the stimulation target site.

[0062] Further, the electrical stimulation control unit 114 further controls the intensity of the electrical stimulation to the muscle of the stimulation target site. Therefore, according to the exercise assistance device 10 according to the first embodiment, it is possible to present an electrical stimulation of a necessary intensity at a necessary timing to the muscles of the stimulation target site.

[0063] Further, the muscle synergy estimation unit 112 performs muscle synergy analysis using non-negative matrix factorization from the information of the myoelectric potential measured for a plurality of muscles, thereby estimating a muscle synergy indicating a combination of muscles that operate in cooperation. The stimulation site selection unit 113 compares the muscle synergy estimated by the muscle synergy estimation unit 112 with a predetermined target muscle synergy, and selects the muscles of the stimulation target site based on the comparison result. Therefore, according to the exercise assistance device 10 according to the first embodiment, it is possible to assist the movement by setting a muscle synergy corresponding to the target movement.

[0064] [Second Embodiment] Next, a second embodiment of the present invention will be described. The second embodiment is configured to present an electrical stimulation at the moment of a specific operation, for example, at the moment when a specific note is pressed in piano performance. In the following description, for parts that are the same as those in the first embodiment, the same reference numerals as those used in the first embodiment are given, and the description thereof will be omitted.

[0065] The hardware configuration of the exercise assistance device 10 according to the second embodiment of the present invention is the same as that of the first embodiment. However, the input / output interface 13 is connected to an external device so that the trigger signal indicating the moment of the specific operation is input from the external device. Alternatively, the communication interface 14 communicates with the external device so as to receive the trigger signal transmitted from the external device.

[0066] FIG. 9 is a block diagram showing an example of the functional configuration of the motion assistance device 10 according to the second embodiment of the present invention. In the second embodiment, in addition to the configuration of the first embodiment, the processing unit 11 includes a trigger signal acquisition unit 116. The trigger signal acquisition unit 116 acquires a trigger signal from an external device via the input / output interface 13 or the communication interface 14. The trigger signal acquisition unit 116 supplies the trigger signal acquired from the external device to the electrical stimulation control unit 114. The electrical stimulation control unit 114 controls the presentation timing of the electrical stimulation based on the trigger signal supplied from the trigger signal acquisition unit 116.

[0067] The operation processing procedure of the motion assistance device 10 is the same as that of the first embodiment except for the electrical stimulation presentation processing subroutine executed in step S8. FIG. 10 is a flowchart showing the electrical stimulation presentation processing subroutine in the motion assistance device 10 according to the second embodiment.

[0068] The processor 11A operates as the trigger signal acquisition unit 116 to determine whether there is a trigger signal from an external device (step S86). That is, the processor 11A determines whether a trigger signal is input from an external device via the input / output interface 13, or whether a trigger signal from an external device is received via the communication interface 14.

[0069] When it is determined that there is a trigger signal, the processor 11A operates as the electrical stimulation presentation unit 115 to determine which of the muscles of the selected stimulation target site to present the electrical stimulation based on the trigger signal, and causes the electrical stimulation to be presented to the discriminated muscle of the stimulation presentation target (step S87). That is, the processor 11A can analyze the trigger signal to determine which muscle of the selected stimulation target site is triggered. The processor 11A determines the timing of presenting the electrical stimulation based on the supply timing of this trigger signal, and also determines the intensity of the electrical stimulation based on the muscle synergy estimated from the myoelectric potential values measured from an expert and stored in the target muscle synergy storage unit 121 as described in the first embodiment.

[0070] After that, or when it is determined in step S86 that there is no trigger signal, the processor 11A determines whether or not a specific movement that the learner is learning has ended (step S85).

[0071] If it is determined that the specific movement to be learned has not ended yet, the processor 11A proceeds to the process of step S86.

[0072] And if it is determined that the specific movement to be learned has ended, the processor 11A ends the operation of this electrical stimulation presentation processing subroutine.

[0073] In this way, until the specific movement to be learned ends, the processor 11A repeats presenting electrical stimulation to the muscles of the stimulation target site every time a trigger signal is input or received from an external device.

[0074] If the specific movement to be learned is, for example, the performance of a piano scale as described in the example of the first embodiment, in the movement assistance device 10 according to the second embodiment, by using the MIDI information of the piano, it is possible to present electrical stimulation at the timing of pressing a specific keyboard. Thereby, when the learner learns scale performance, the movement of the arm during finger insertion can be assisted by electrical stimulation. For example, at the moment when the flexor digitorum superficialis muscle of a beginner who is the learner becomes active, for example, at the moment when the keyboard of the note "mi" is pressed, a trigger signal is given from the piano, and the movement assistance device 10 contracts the deltoid muscle of the learner by electrical stimulation, so that the flexor digitorum superficialis muscle and the deltoid muscle of the learner can be made to operate in cooperation. Thereby, when the learner presses the keyboard of the note "mi", the learner's arm abducts at the same time, making it easier to perform the finger insertion movement, and enabling smooth scale performance like that of an expert.

[0075] As described in detail above, also with the movement assistance device 10 according to the second embodiment, similar to the first embodiment, it is possible to determine the muscles to which electrical stimulation should be presented and the presentation timing when causing a plurality of muscles to operate in cooperation.

[0076] Further, the electrical stimulation control unit 114 determines the presentation timing of the electrical stimulation to the muscle of the stimulation target site by using the timing information input from the outside. Therefore, according to the exercise support device 10 according to the second embodiment, it is possible to determine the presentation timing of the electrical stimulation without performing special processing.

[0077] [Other Embodiments] Note that the present invention is not limited to the above embodiments.

[0078] For example, the exercise support device 10 may be a combination of the first embodiment and the second embodiment. That is, the presentation timing of the electrical stimulation may be controlled by either the myoelectric potential value of the muscles that cooperate or the trigger signal. Further, by combining both the myoelectric potential value and the trigger signal with weighting or priority, the presentation timing of the electrical stimulation may be controlled based on both the myoelectric potential value and the trigger signal.

[0079] Also, in the first and second embodiments, the exercise support device 10 has been described as connecting the myoelectric sensor 20 and the electrical stimulation device 30 to the input / output interface 13, but the myoelectric potential value and / or the drive signal may be received and / or transmitted by wireless communication between the myoelectric sensor 20 and / or the electrical stimulation device 30 through the communication interface 14.

[0080] Further, in addition to the predetermined target muscle synergy, the target myoelectric potential value for the muscle of the stimulation target site may be stored in the target muscle synergy preservation unit 121.

[0081] Furthermore, the exercise support device 10 may be configured as a dedicated device instead of a general-purpose device such as a PC.

[0082] In addition, the flow of each process described with reference to the flowchart is not limited to the described procedures. The order of some steps may be changed, some steps may be performed simultaneously, or the processing content of some steps may be modified.

[0083] In addition, the methods described in each embodiment can be stored as a processing program (software means) to be executed by a computer on a recording medium such as a magnetic disk (e.g., a floppy (registered trademark) disk, a hard disk, etc.), an optical disk (e.g., a CD-ROM, a DVD, an MO, etc.), or a semiconductor memory (e.g., a ROM, a RAM, a flash memory, etc.), and can also be transmitted and distributed via a communication medium. Note that the program stored on the medium includes a setting program for configuring software means (including not only the execution program but also tables and data structures) to be executed by a computer in the computer. The computer that realizes this device reads the program recorded on the recording medium, and in some cases, constructs software means by the setting program, and executes the above-described processing by being controlled by this software means. Note that the recording medium referred to in this specification includes not only a medium for distribution but also storage media such as a magnetic disk and a semiconductor memory provided inside a computer or in a device connected via a network.

[0084] In short, the present invention is not limited to the above-described embodiments as they are, and at the implementation stage, the components can be modified and embodied without departing from the gist thereof. Also, various inventions can be formed by appropriately combining a plurality of components disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined.

Explanation of Reference Numerals

[0085] 10... Motion assistance device 11... Processing unit 11A... Processor 11B... Program memory 12…Data memory 13…Input / output interface 14…Communication interface 15…Bus 20…Electromyogram sensor 30…Electrical stimulation device 40…Electrode for electromyogram measurement and electrical stimulation 111…Electromyogram acquisition unit 112…Muscle synergy estimation unit 113…Stimulation site selection unit 114…Electrical stimulation control unit 115…Electrical stimulation presentation unit 116…Trigger signal acquisition unit 121…Target muscle synergy storage unit 122…Electromyogram memory unit 123…Estimated muscle synergy memory unit 124…Stimulation site memory unit

Claims

1. A muscle synergy estimation unit that estimates muscles that are operating in cooperation based on information on electromyographic potentials measured for a plurality of muscles; A stimulation site selection unit that selects a muscle of a stimulation target site for which an electrical stimulation is to be presented based on the estimation result of the muscle synergy estimation unit; An electrical stimulation control unit that controls the presentation timing of an electrical stimulation to the muscle of the stimulation target site selected by the stimulation site selection unit; comprising: The electrical stimulation control unit calculates the root mean square of samples of a certain window width of the information on the electromyographic potentials of the muscles that cooperate with the muscle of the stimulation target site, and determines that the period during which the calculated root mean square exceeds a preset threshold value is the presentation timing of the electrical stimulation to the muscle of the stimulation target site. A movement assistance device.

2. The electrical stimulation control unit further controls the intensity of the electrical stimulation to the muscle of the stimulation target site. The movement assistance device according to claim 1.

3. The muscle synergy estimation unit performs muscle synergy analysis using non-negative matrix factorization on the information on the electromyographic potentials measured for the plurality of muscles, thereby estimating a muscle synergy indicating a combination of the muscles that are operating in cooperation; The stimulation site selection unit compares the muscle synergy estimated by the muscle synergy estimation unit with a predetermined target muscle synergy, and selects the muscle of the stimulation target site based on the comparison result. The movement assistance device according to claim 1 or 2.

4. A movement assistance method in a movement assistance device that performs movement assistance by applying an electrical stimulation to a muscle, the method comprising: estimating muscles that are operating in cooperation based on information on electromyographic potentials measured for a plurality of muscles; selecting a muscle of a stimulation target site for which an electrical stimulation is to be presented based on the result of the estimation of the muscles that are operating in cooperation; controlling the presentation timing of an electrical stimulation to the selected muscle of the stimulation target site; calculating the root mean square of samples of a certain window width of the information on the electromyographic potentials of the muscles that cooperate with the muscle of the stimulation target site, and determining that the period during which the calculated root mean square exceeds a preset threshold value is the presentation timing of the electrical stimulation to the muscle of the stimulation target site; A movement assistance method including the above.

5. A movement assistance program that causes a computer to execute the processing by each unit of the movement assistance device according to any one of claims 1 to 3.

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