Exercise aid device

Abstract

The present invention aims to provide an exercise assistance device that can effectively provide exercise assistance. [Solution] The exercise assist device of the present invention comprises at least an electrode group having a plurality of electrodes for detecting myoelectric potentials; an analysis means for analyzing and identifying the position of a neuromuscular junction in a muscle and the magnitude of the myoelectric potential at the neuromuscular junction based on a plurality of myoelectric potentials detected by the plurality of electrodes; a control means for generating a control signal corresponding to the magnitude of the myoelectric potential at the neuromuscular junction identified by the analysis means; an electrical stimulation generating means for generating an electrical stimulation controlled by the control means; and an electrical stimulation applying means for applying the electrical stimulation to the neuromuscular junction whose position has been identified by the analysis means. The electrode group is provided on the skin surface of at least two types of muscles, namely agonist muscles, antagonist muscles, and synergist muscles, and the electrical stimulation applying means is an electrode that has detected the myoelectric potential at the neuromuscular junction.

Description

Technical Field

[0001] The present invention relates to an exercise assistance device used for exercise assistance such as walking assistance.

Background Art

[0002] Falls among the elderly are on the increase year by year, and walking disorders due to decreased muscle strength and walking ability are considered the main cause.

[0003] In addition, as one case of quadriplegia related to cerebral infarction, there is what is called a dropped foot. In dropped foot patients, due to relaxation of the dorsiflexor muscle group of the ankle joint and hyperactivity of the plantar flexor muscle group, dorsiflexion of the ankle joint is difficult. Therefore, when walking and swinging the leg, in healthy people, the ankle joint dorsiflexes due to contraction of the dorsiflexor muscle group and the leg swings out smoothly, whereas in dropped foot patients, the ankle joint does not dorsiflex and the toes touch the ground. Due to this "dragging gait", the patient's walking has become difficult.

[0004] As a means of assisting and improving such walking disorders and dragging gait, an exercise assistance device using functional electrical stimulation has been developed.

[0005] For example, in Patent Document 1, there is proposed an exercise assistance device comprising a first electrode for detecting myoelectricity, control means for generating a control signal according to the magnitude of the myoelectricity detected by the first electrode, electrical stimulation means for generating electrical stimulation controlled by the control means, and a second electrode for applying the electrical stimulation generated by the electrical stimulation means.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in order to adjust gait, it is necessary to electrically stimulate multiple types of muscles that work together in a time-delayed manner. The exercise assistance device described in Patent Document 1 electrically stimulates the deep peroneal nerve, which is the nerve that innervates the dorsiflexor muscles of the ankle joint of the paralyzed limb (tibialis anterior, extensor digitorum longus, extensor hallucis longus, etc.). As this electrically stimulates many muscle groups in the lower leg at once, it is not possible to adjust gait effectively.

[0008] The present invention aims to provide an exercise assistance device that can effectively provide exercise assistance. [Means for solving the problem]

[0009] Generally, various movements in the human body are performed by the contraction and relaxation of various muscles, and these muscle contractions and relaxations are generated by impulses transmitted from motor nerves to muscle fibers. The motor nerves that transmit these impulses are connected to muscle fibers at a specific site, which is called the neuromuscular junction. The inventors of this invention conducted diligent research to solve the aforementioned problem and found that by identifying the neuromuscular junctions in multiple types of muscles that cooperate in specific movements and applying controlled electrical stimulation precisely to these neuromuscular junctions, it is possible to effectively provide exercise assistance such as walking assistance. This invention was completed by further research based on these findings.

[0010] In other words, the present invention provides inventions in the following embodiments. <1> An electrode group having multiple electrodes for detecting electromyography, An analysis means for analyzing and identifying the location of the neuromuscular junction in the muscle and the magnitude of the electromyographic potential at the neuromuscular junction, based on the multiple electromyographic potentials detected by the multiple electrodes, Control means that generates a control signal corresponding to the magnitude of the electromyographic potential at the neuromuscular junction identified by the analysis means, An electrical stimulation generating means that generates electrical stimulation controlled by the control means, The system comprises at least an electrical stimulation application means for applying the electrical stimulation to the neuromuscular junction whose location has been identified by the analysis means, The electrode group is provided on the skin surface of at least two of the muscles, including prime mover muscles, antagonist muscles, and synergistic muscles. The aforementioned electrical stimulation application means is an electrode that detects myoelectric potential at the neuromuscular junction, and is an exercise assistance device. <2> The electrode group is provided on (1) the skin surface over the prime mover and antagonist muscles, (2) the skin surface over the prime mover and synergistic muscles, (3) the skin surface over the antagonist and synergistic muscles, or (4) the skin surface over the prime mover, antagonist, and synergistic muscles. <1> The exercise assist device described above. <3> The electrode is a fiber electrode. <1> or <2> The exercise assist device described above. [Effects of the Invention]

[0011] The exercise assistance device of the present invention is effective for assisting exercise, restoring motor function, and strengthening muscles, and is particularly effective as a means of assisting and improving walking disorders and dragging gait. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a supporter having an electrode group used in an exercise assistance device according to one embodiment of the present invention. [Figure 2] This is a block diagram illustrating the configuration of an exercise assistance device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0013] 1. Configuration of the exercise assistance device The exercise assistance device of the present invention comprises an electrode group having multiple electrodes for detecting electromyographic potentials, An analysis means for analyzing and identifying the location of the neuromuscular junction in the muscle and the magnitude of the electromyographic potential at the neuromuscular junction, based on the multiple electromyographic potentials detected by the multiple electrodes, Control means for generating a control signal according to the magnitude of the muscle potential at the neuromuscular junction identified by the analysis means; Electrical stimulation generating means for generating electrical stimulation controlled by the control means; Electrical stimulation applying means for applying the electrical stimulation to the neuromuscular junction whose position has been identified by the analysis means, and comprising at least: The electrode group is provided on the skin surface of at least two types of muscles among the prime mover, antagonist muscle, and synergistic muscle; The electrical stimulation applying means is an electrode that detects the muscle potential at the neuromuscular junction, and is characterized in that.

[0014] Hereinafter, the configuration and usage mode of the exercise assist device of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram of a supporter having an electrode group used in an exercise assist device according to an embodiment of the present invention. FIG. 2 is a block diagram for explaining the configuration of an exercise assist device according to an embodiment of the present invention.

[0015] [Electrode group] Electrode group 1 has multiple electrodes for detecting muscle electromyography (EMG), and specifically, as shown in Figure 1, it includes multiple electrodes 2 arranged in a matrix on a flexible base sheet 3. The base sheet 3 is not particularly limited, but examples include cloth sheets (e.g., woven sheets, knitted sheets, felt sheets, nonwoven sheets) and resin sheets. Each electrode 2 on the base sheet 3 is connected to a connector 5 by wiring 4, and the connector 5 is connected to a power circuit. To accurately identify the location of the neuromuscular junction in the muscle to be measured, each electrode 2 is evenly arranged along the direction of the muscle fibers when the base sheet 3 with electrode group 1 is placed on the skin surface of each muscle. If there is crosstalk across different muscles (potential interference from other muscles adjacent to the muscle being measured), the EMG will not have a normal waveform. Therefore, the electrodes 2 are arranged in a matrix along the direction of the muscle fibers, and there is no crosstalk. After detecting the potential change in the direction of the muscle fibers and identifying the direction of the arrangement of the electrodes 2, the waveforms between the electrodes are compared to identify the neuromuscular junction that is the signal source. The shape of electrode 2 is not particularly limited and can be, for example, square, rectangular, circular, or elliptical. The size of each electrode 2 (length and width for squares, diameter for circulars, and major axis for ellipses) is usually about 20-30 mm, and is preferably 5-10 mm in order to accurately pinpoint the location of the neuromuscular junction in the muscle. The ideal distance between electrodes (distance between the centers of electrodes 2) is usually about 10-20 mm, and is preferably 5-10 mm in order to accurately pinpoint the location of the neuromuscular junction in the muscle. Noise is more likely to occur as the distance between electrodes increases. The number of electrodes 2 and the aspect ratio when electrodes 2 are arranged vertically and horizontally will vary depending on the muscle being measured, so it is necessary to adjust them appropriately according to the muscle being measured. For example, when targeting the vastus lateralis muscle of the quadriceps femoris (5 cm x 15 cm, 75 cm) 2 ) If the goal is simply to evaluate muscle activity, electrodes are usually placed evenly along the direction of the muscle fibers, so around 10 to 24 electrodes are sufficient. However, to accurately pinpoint the location of the neuromuscular junction in the muscle, 120 to 480 electrodes are preferable.

[0016] The electrode 2 can be formed using a conductive material (e.g., metals such as silver, nickel, molybdenum; carbon materials such as carbon black, graphite; conductive paste; metal plate; metal foil; metal fiber, etc.) without particular limitation. However, from the viewpoints of having a soft touch, excellent flexibility, being able to stably detect myoelectric potential even when performing various operations, and being less likely to have a decrease in myoelectric potential detection performance even when repeatedly used, it is preferably a fiber electrode.

[0017] The fiber electrode includes an embroidered portion having stitches of conductive yarn.

[0018] The conductive yarn used for the fiber electrode is a yarn containing metal fiber. Examples of the metal fiber include metal film fibers obtained by coating, plating, metal vapor deposition or sputtering a metal such as copper, nickel, silver, etc. on the fiber surface; metal fibers made of a metal (single substance) such as aluminum or tungsten; fibers containing fine particles such as carbon, conductive ceramic, metal, etc. and having conductivity.

[0019] As the metal fiber, a monofilament yarn of the above-mentioned metal fiber (e.g., a monofilament yarn of a metal fiber made of a single metal (metal yarn) or a monofilament yarn of a metal film fiber) may be used, or a multifilament yarn in which a plurality of types and a plurality of metal fibers are twisted or aligned may be used.

[0020] The thickness of the metal fiber is usually about 1 to 200 μm in diameter.

[0021] The conductive yarn used in fiber electrodes may contain organic fibers to improve the durability of the fiber electrodes against repeated use. Examples of organic fibers include natural fibers such as cotton, linen, wool, and silk; synthetic fibers such as polyester, nylon, acrylic, polyolefin, para-aramid, meta-aramid, polyarylate, and polybenzoxazole; water-soluble fibers such as water-soluble vinylon; and regenerated fibers such as rayon. Examples of forms of organic fibers include spun yarn, filament yarn, composite yarn, and plywood combining these. Furthermore, the organic fiber may be a raw yarn that has not undergone false-twist processing, or it may be a false-twisted yarn. It may also be a yarn made by twisting raw yarn or false-twisted yarn.

[0022] The fiber electrodes can be formed on the base sheet by, for example, machine embroidery. Examples of stitch types include running stitch, cross stitch, tatami stitch, and chain stitch.

[0023] The base sheet 3 may have one electrode group 1 for detecting the electromyographic potential of one muscle, or it may have two or more electrode groups 1 separately at predetermined intervals for detecting the electromyographic potential of two or more muscles. However, when two or more electrode groups 1 are separately at predetermined intervals on the base sheet 3, the position of each electrode group 1 on the base sheet 3 must be adjusted to match the position of each muscle on the body part to which it is attached, and this adjustment is complicated. Therefore, it is preferable to create one large electrode group 1 by continuously arranging electrodes 2 in a matrix on the base sheet 3 in the longitudinal direction (circumferential direction of a specific part of the body), and then wrap the base sheet 3 having this large electrode group 1 around a specific part of the body, so as to cover the entire skin surface over two or more muscles. By using a base sheet 3 having such a large electrode group 1, it is not necessary to adjust the position of each electrode group 1 to match each muscle, thus increasing convenience.

[0024] The base sheet 3 having the electrode group 1 is preferably provided on one side (the side that contacts the skin) of the supporter 6 or pad in order to facilitate attachment to various parts of the body and to provide strength that can withstand repeated use. The size of the electrode group 1 is appropriately adjusted according to the type and size of the muscle in the part of the body to which it is attached.

[0025] Electrode group 1 is placed on the skin surface of at least two types of muscles, including prime mover muscles, antagonist muscles, and synergistic muscles. By identifying each neuromuscular junction in multiple types of muscles that cooperate in a specific movement and applying controlled electrical stimulation precisely to each neuromuscular junction, it is possible to stimulate and contract each muscle in a timely manner. The prime mover muscles, antagonist muscles, and synergistic muscles to which electrode group 1 is placed vary depending on the body part and the type of movement, so it is necessary to appropriately identify them according to the body part and the type of movement. Specifically, electrode group 1 is placed on (1) the skin surface of prime mover muscles and antagonist muscles, (2) the skin surface of prime mover muscles and synergistic muscles, (3) the skin surface of antagonist muscles and synergistic muscles, or (4) the skin surface of prime mover muscles, antagonist muscles, and synergistic muscles.

[0026] Specifically, when the exercise assistance device of the present invention is attached to the lower body for the purpose of assisting walking, the electrode group 1 is provided on the skin surface of the quadriceps femoris muscle, which is the prime mover, and the iliopsoas muscle, rectus abdominis muscle, and tibialis anterior muscle, which are synergistic muscles. Furthermore, when the exercise assistance device of the present invention is attached to the lower body for the purpose of assisting standing, the electrode group 1 is provided on the skin surface of the quadriceps femoris muscle, which is the prime mover, and the rectus abdominis muscle and tibialis anterior muscle, which are synergistic muscles, on the front of the body, or on the skin surface of the hamstrings (biceps femoris, semitendinosus, and semimembranosus), which are the prime mover, and the erector spinae muscle and gastrocnemius muscle, which are synergistic muscles, on the back of the body, or on all of these. Furthermore, when the exercise assist device of the present invention is worn on the upper body during bench press for muscle strengthening purposes, electrode group 1 is placed on the skin surface over the primate muscle (pectoralis major), the antagonist muscles (latissimus dorsi and biceps brachii), and the synergistic muscles (pectoralis minor, deltoid and triceps brachii). Furthermore, when the exercise assist device of the present invention is worn on the lower body during squats for muscle strengthening purposes, electrode group 1 is placed on the skin surface over the primate muscles (quadriceps femoris, gluteus maximus and hamstrings), and the synergistic muscles (erector spinae and triceps surae). Furthermore, when the exercise assist device of the present invention is worn on the lower body during leg extensions for muscle strengthening purposes, electrode group 1 is placed on the skin surface over the primate muscle (quadriceps femoris), the antagonist muscle (biceps femoris), and the synergistic muscle (tibialis anterior). Furthermore, when the exercise assist device of the present invention is attached to the lower body during leg curls for the purpose of muscle strengthening, the electrode group 1 is placed on the skin surface over the biceps femoris (primary muscle), the quadriceps femoris (antagonist muscle), and the semitendinosus, semimembranosus, and gastrocnemius muscles (synergistic muscles).

[0027] The configuration and usage of the exercise assistance device of the present invention will be explained using the case of use for the purpose of assisting walking as an example. First, as shown in Figure 2, the electrode group 1 of the exercise assistance device of the present invention is placed in contact with the surface of the skin 9 on the quadriceps femoris muscle, which is the prime mover muscle 7, and the psoas muscle, rectus abdominis muscle, and tibialis anterior muscle, which are the synergistic muscles 8. When force is applied to the prime mover muscle 7 and synergistic muscles 8 in the lower body wearing the exercise assistance device of the present invention, impulses corresponding to the activity level of these muscles are transmitted from the motor nerve through the neuromuscular junction along the muscle fibers to both sides, and myoelectric potentials are generated in each muscle area. At each electrode of the electrode group 1 placed in contact with the surface of the skin 9 on each muscle, myoelectric potentials are detected in approximately the same manner, with the potential waveform changing at an earlier time for electrodes closer to the neuromuscular junction and at a later time for electrodes further from the neuromuscular junction. The detected myoelectric potentials are sent from each electrode group 1 through each filter circuit 10 to each amplifier circuit 11 connected by each connecting wire.

[0028] [Filter circuit] The weak electromyographic potential detected by each electrode group 1 is affected by changes in skin condition (such as sweat and sebum) and contact conditions between the skin and the electrodes (such as pressure), which alters the impedance between the skin and the electrodes, resulting in superimposed noise. In addition, depending on the surrounding environment, electromagnetic noise may be superimposed. The filter circuit 10 is designed to remove these noise components and extract only the weak electromyographic potential.

[0029] [Amplifier circuit] As shown in Figure 2, the amplifier circuit 11 is connected to each electrode group 1 through the filter circuit 10 via connecting wires. The amplifier circuit 11 amplifies the weak myoelectric potential detected by each electrode group 1 to a voltage suitable for signal processing. The output terminal of the amplifier circuit 11 is connected to the A / D conversion circuit 12 via connecting wires.

[0030] [A / D conversion circuit] The A / D conversion circuit 12 converts each analog voltage amplified by the amplifier circuit 11 into digital signals for processing by the diagnostic circuit (CPU; central processing unit) 13. The output terminal of the A / D conversion circuit 12 is connected to the diagnostic circuit (CPU) 13 by connecting wires.

[0031] [Diagnostic Circuit (CPU)] The diagnostic circuit (CPU) 13 serves as an analysis means for analyzing and identifying the location of the neuromuscular junction in the muscle and the magnitude of the electromyogram at the neuromuscular junction based on the multiple electromyograms detected by the multiple electrodes, and as a control means for generating control signals corresponding to the magnitude of the electromyogram at the neuromuscular junction identified by the analysis means.

[0032] The diagnostic circuit (CPU) 13 analyzes each input digital signal and generates electrical signals to indicate the location of the neuromuscular junction of each muscle. The location of the neuromuscular junction of each muscle is identified by first identifying the direction of muscle fiber alignment from the electromyogram waveform, then comparing the temporal changes in the waveform to classify the direction of electrical movement and identify the signal source. Since the neuromuscular junction is slightly shifted depending on the muscle fiber (generally in the center), the neuromuscular junction is identified for each muscle fiber course. The diagnostic circuit (CPU) 13 also generates control signals corresponding to the magnitude of the electromyographic potential at each neuromuscular junction, and these signals are sent to the pulse generation circuit 14, which is connected by connecting wires. The diagnostic circuit (CPU) 13 controls the pulse generation circuit 14 so that electrical stimulation is applied to the neuromuscular junction of each muscle only when the electromyographic potential exceeds a preset threshold. In other words, the diagnostic circuit (CPU) 13 controls the timing of applying electrical stimulation to the neuromuscular junction of each muscle during the walking phase, thereby appropriately controlling the timing of muscle contraction and relaxation. This ensures that walking assistance is provided appropriately.

[0033] [Pulse generation circuit] The pulse generation circuit 14 functions as an electrode stimulation generating means (pulse generation circuit) that generates electrical signals to apply electrical stimulation to the neuromuscular junctions of each muscle based on signals sent from the diagnostic circuit (CPU) 13. The pulse generation circuit 14 also controls the electrodes that detect myoelectric potentials at the neuromuscular junctions to apply electrical stimulation. This allows controlled electrical stimulation to be applied precisely to the neuromuscular junctions of each muscle, stimulating and contracting each muscle at the right time, thereby enabling appropriate walking assistance. The intensity of the electrical stimulation, the duration of application, and the pulse frequency are adjusted as appropriate according to the wearer's level of walking assistance.

[0034] [Switching circuit] The exercise assistance device of the present invention may be switchable between a circuit for detecting electromyography (EMG) and a circuit for electrical stimulation in order to simplify the electrical circuit. The switching circuit 15 is composed of a switch (such as a MOS-FET) controlled by a diagnostic circuit (CPU) 13, and insulates the pulse generation circuit 14 and the electrode group 1 when detecting EMG to prevent the introduction of electrical stimulation artifacts. From the viewpoint of reliability and miniaturization, it is preferable to use a semiconductor relay (such as a MOS-FET).

[0035] [Power circuit] The power supply circuit 16 is a power source for supplying power to the diagnostic circuit (CPU) 13 and the pulse generation circuit 14. Examples of power supply circuits 16 include AC adapters that convert AC power (household commercial power) to DC voltage, mobile batteries, and storage batteries.

[0036] Although the above explanation used the example of use for walking assistance, the exercise assistance device of the present invention is effective through a similar mechanism of action in other forms of exercise assistance, motor function recovery, and muscle strengthening.

[0037] 2. Forms of exercise assistance devices Examples of the exercise assistance device of the present invention include: a plurality of pads each having one electrode group connected to a power circuit provided on a supporter by connecting wires; a supporter or corset on which two or more electrode groups are partially provided, or a single continuous electrode group is provided around the entire circumference; a stretchable or compression garment (e.g., shirt, spats, tights, leggings, socks, etc.) each having multiple pads with one electrode group provided at specific positions on the inside; a garment on which two or more electrode groups (e.g., electrode groups made of fiber electrodes) are formed on the fabric at specific positions on the inside of the garment; or an electrode group is formed on the entire fabric on the inside of the garment. The power source for driving the exercise assistance device of the present invention may be a battery built into the device or an external power source.

[0038] 3. Purpose of using exercise assistance devices The exercise assistance device of the present invention is used for exercise assistance such as walking assistance; and for purposes such as strengthening muscles in training such as bench press, squat, leg extension, and leg curl. In particular, it is effective as a means of assisting and improving walking disorders and limping. [Explanation of Symbols]

[0039] 1: Electrode group 2: Electrode 3: Base sheet 4: Wiring 5: Connector 6: Supporter 7: Primary muscle 8: Collaborative muscles 9:Skin 10: Filter Circuit 11: Amplifier Circuit 12: A / D conversion circuit 13: Diagnostic circuit (CPU) 14: Pulse generation circuit 15: Switching circuit (IN / OUT switching) 16: Power supply circuit

Claims

1. An electrode group having multiple electrodes for detecting electromyography, An analysis means for analyzing and identifying the location of the neuromuscular junction in the muscle and the magnitude of the electromyographic potential at the neuromuscular junction, based on the multiple electromyographic potentials detected by the multiple electrodes, Control means that generates a control signal corresponding to the magnitude of the electromyographic potential at the neuromuscular junction identified by the analysis means, An electrical stimulation generating means that generates electrical stimulation controlled by the control means, The system comprises at least an electrical stimulation application means for applying the electrical stimulation to the neuromuscular junction whose location has been identified by the analysis means, The electrode group is provided on the skin surface of at least two of the muscles, including prime mover muscles, antagonist muscles, and synergistic muscles. The aforementioned electrical stimulation application means is an electrode that detects myoelectric potential at the neuromuscular junction, and is an exercise assistance device.

2. The exercise assist device according to claim 1, wherein the electrode group is provided on (1) the skin surface over the prime mover muscle and the antagonist muscle, (2) the skin surface over the prime mover muscle and the synergistic muscle, (3) the skin surface over the antagonist muscle and the synergistic muscle, or (4) the skin surface over the prime mover muscle, the antagonist muscle, and the synergistic muscle.

3. The exercise assist device according to claim 1 or 2, wherein the electrode is a fiber electrode.

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