JP2013094305A - Functional electric stimulation system for walk assistance by driving foot joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional electric stimulation system enabling a user to more naturally walk.SOLUTION: The functional electric stimulation system for walk assistance includes: a drive force imparting device for imparting a drive force to a foot joint by individually electrically stimulating each of a plurality of muscles around of the foot joint; stimulation electrode supporters 1, 5 to be attached to the lower extremity to give electric stimulus; sensors 3, 4 for detecting that the legs contact the ground; and sensors 7, 8, 12, 13 for detecting the angle of foot joints respectively. The system estimates muscular output online on the basis of a skeleton model of a passive walk mode and a muscle skeleton mathematical model, converts the estimated output into a stimulus pattern corresponding to each of the muscles, and causes the stimulation electrode supporters to individually electrically stimulate each of the muscles based on a stimulus pattern corresponding to each of the muscles.

Description

  The present invention provides a means for artificially supporting walking from the initial stage of injury for gait disturbance due to stroke, spinal cord injury, and other central nerve palsy, and lower limbs associated with aging, particularly the lower leg The present invention relates to a Functional Electrical Stimulation (FES) system that provides a means for assisting in the reduction of muscle output of a person by training.

  In normal walking speed, the driving force at the end of the stance phase is realized mainly by the ankle joint, and the kicking force by the triceps surae which is the flexor of the ankle joint during the kicking out phase, the corresponding joint It has been clarified in the gait motion analysis and electromyogram analysis that the activity of the extensor group is required to control the overall rigidity. On the other hand, functional electrical stimulation (FES) devices are recognized to provide a powerful technique for functional reconstruction of paralyzed limbs.

  Various proposals have been made for locomotion control. Non-patent document 1 describes electrical stimulation of ankle flexor and extensor muscle group, and patent document 1, non-patent document 2 and non-patent document 3 describe passive. There is a description about walking and its feedback control. Non-Patent Documents 4 to 6 have descriptions related to skeletal models, and Non-Patent Document 7 has descriptions related to musculoskeletal mathematical models. Non-patent document 8 describes the electrical response of the stimulated muscle.

JP 2005-88113 A

Kesar, T.M., Perumal R., et al, Functional electrical stimulation of ankle plantar anddorsi-flexor muscles: effects on post-stroke gait, Stroke, 40 (12), 2009 McGeer, T., Passive dynamic walking, IJRR, 19 (2), 1990 Hobbelen, D.G.E. And Wisse, M., Ankle actuation for limit cycle walkers, IJRR, 27 (6), 2008 Lelas, J. L., Merriman, G. J., et al, Predicting peak kinematic and kinetic parameters from gait speed, Gait and Posture 17, 106-112, 2003 FrigoC., Crenna P. and Jensen, L. M .; Moment-angle relationship at lower limb jointsduring human walking at different velocities, J. Electromyogr. Kinesiol., 6 (3), 177-190, 1996 Toshiyasu Yamamoto, Hiroaki Kuno, Alternating movement response of lower limbs by sensory stimulation around the foot when walking on a weight-supported treadmill, 21st Biomechanism Symposium, 435-446, 2009 Kazunori Hase, SIMM, ARMO, AnyBody motion analysis, Journal of Biomechanism Society 33 (3), 2009 T. Yamamoto, Control of movement of a skeletal joint by functional electricalstimulation via surface Electrodes, Ph.D. thesis, University of Wisconsin-Madison, 1985

  However, conventional functional electrical stimulation devices have not yet achieved natural human walking, and there is a demand for the development of functional electrical stimulation devices that enable walking close to a natural state.

  In view of the above situation, an object of the present invention is to provide a functional electrical stimulation system that makes it possible to approach more natural walking.

  In order to achieve the above object, a functional electrical stimulation system according to the present invention is a functional electrical stimulation system for assisting walking, and each of a plurality of muscles in an ankle joint muscle group is electrically stimulated individually. A driving force applying device that applies joint driving force; a stimulation electrode supporter that is attached to a lower limb to perform the electrical stimulation; and a sensor that detects leg ground contact information and a joint angle. Based on a detection signal of the sensor The muscle output is estimated online by the skeletal model of passive walking style and the musculoskeletal mathematical model, the estimated muscle output is converted into a stimulation pattern corresponding to each muscle, and the muscle is supported by the stimulation electrode supporter. Each of the muscles is individually electrically stimulated with a corresponding stimulation pattern.

  According to the present invention, since each of the plurality of muscles in the muscle group around the ankle joint is individually electrically stimulated to apply the ankle joint driving force, the driving force of the ankle joint can be obtained with appropriate rigidity. More specifically, while considering the ankle joint stiffness at the end of the stance phase, by individually electrically stimulating each muscle of the muscles around the ankle joint, an ankle joint driving force close to natural walking can be obtained, A more natural walk can be realized.

  It is preferable that the stimulation electrode supporter separately provide stimulation electrodes corresponding to the gastrocnemius and soleus so that the gastrocnemius and soleus as the ankle flexor muscles can be electrically stimulated individually. According to this configuration, the gastrocnemius muscle and the soleus muscle, which have different actions due to electrical stimulation, can be electrically stimulated individually, which is advantageous in obtaining an ankle joint driving force that is close to natural walking.

  The stimulation electrode supporter is preferably provided with a stimulation electrode so as to stimulate the anterior tibial muscle as an ankle extensor muscle.

  The stimulation electrode supporter has separate stimulation electrodes for the gastrocnemius, soleus and anterior tibial muscles so that the gastrocnemius, soleus and anterior tibial muscles as ankle extensors can be electrically stimulated individually. It is preferable that the finger extensor can be electrically stimulated together with the anterior tibial muscle.

  The stimulation electrode supporter is preferably provided with electrodes so that the quadriceps muscle, which is the knee joint extensor, can be electrically stimulated in addition to the muscles of the lower leg. According to this structure, the electrical stimulation for avoiding the knee break in the stance phase of the anti-leg can be given.

  The stimulation electrode supporter is preferably provided with a stimulation electrode so as to perform electrical stimulation of the long ankle extensor muscle in addition to the electrical stimulation of the anterior tibial muscle in order to perform ankle joint extension operation. According to this configuration, it is possible to provide an electrical stimulus that complements the ankle joint extension operation in the sagittal plane.

  In one gait cycle, the gastrocnemius muscle stimulation in the stance phase is continued with a stimulation intensity enough to bend the knee until the early swing phase, and the quadriceps muscles are electrically stimulated when the anti-legged phase is in the stance phase. Preferably it can be done. According to this configuration, even when there is abnormal muscle tension such as spasticity, the knee can be bent in the early swing phase, and the knee can be prevented from bending in the stance phase of the leg, and the toes It is possible to prevent it from being tripped by being caught.

  The stimulation pulse of the electrical stimulation is a biphasic rectangular wave or a biphasic sine wave, and one channel output composed of a pair of electrodes can simultaneously stimulate one or two or more nerves and muscles. preferable.

  The electrical stimulation employs a voltage control method, the stimulation waveform is a burst wave, the basic pulse width is preferably 2 to 5 kHz, and the stimulation frequency is preferably 20 to 60 Hz. According to this configuration, it is possible to prevent an excessive current due to a variation in impedance between the skin and the electrode from flowing locally.

  The stimulation electrode is preferably formed of a flexible material and has a lead wire attached thereto. According to this configuration, the stimulation electrode can be easily adapted to the skin and can be flexibly deformed with walking. Examples of the flexible material include silver woven fabric or silver fine wire mesh.

  The stimulation electrode supporter is preferably formed by combining a solid member and an elastic member. According to this configuration, since the stimulation electrode supporter includes the expansion / contraction member, it is easy to attach to a wearer having a different size of the lower limb portion, and adhesion to the attachment portion can be improved. The solid member is made of plastic, for example. Depending on the use environment, a solid member having a hole for preventing perspiration may be used.

  The stimulation electrode supporter is formed so as to be openable and closable, and preferably includes fixing means for fixing in a closed state when the stimulation electrode supporter is attached. According to this configuration, the stimulation electrode supporter can be easily attached and detached.

  The stimulation electrode supporter preferably has a recording electrode on one or both legs, and can record electrical responses of the gastrocnemius, soleus and anterior tibial muscles.

  It is preferable to use a foot switch and a foot pressure sensor as sensors for detecting leg contact information, and to use an acceleration sensor or a gyro sensor as a sensor for detecting joint angles of feet and hips.

  The ankle joint moment is estimated online using the skeletal model, or the ankle joint moment is estimated using the relationship between the walking speed and the ankle joint moment based on the empirical formula of a healthy person, and the muscle strength is calculated using the musculoskeletal mathematical model. Preferably, the stimulation pattern is estimated on the assumption that muscle strength is proportional to the stimulation voltage. According to this configuration, it is possible to reduce the burden of online muscle output estimation.

  According to the present invention, since each of a plurality of muscles of the muscle group around the ankle joint is individually electrically stimulated to provide the ankle joint driving force, the ankle joint driving force can be obtained under appropriate rigidity, and natural walking An ankle joint driving force close to can be acquired, and more natural walking can be realized.

The side view which shows the state which attached the stimulation electrode supporter which concerns on one Embodiment of this invention to the leg. The figure which shows the inner side of the leg part stimulation electrode supporter 1 which concerns on one Embodiment of this invention. The perspective view which shows an example of the walk state using the functional electrical stimulation system which concerns on one Embodiment of this invention. The basic stimulus waveform figure of the electrical stimulus concerning one embodiment of the present invention. 1 is a plan view of a prototype recording electrode according to an embodiment of the present invention. The figure which shows an example of the acceleration of the body gravity center at the time of the walk by the soleus muscle and gastrocnemius muscle stimulation which concerns on one Embodiment of this invention.

  Hereinafter, a functional electrical stimulation system according to an embodiment of the present invention will be described with reference to the drawings. The functional electrical stimulation system according to the present embodiment is intended to achieve a more natural walk by electrically stimulating the muscles around the ankle joint with a stimulation electrode supporter attached to the lower limbs.

  FIG. 1 is a side view showing a state in which a stimulation electrode supporter according to an embodiment of the present invention is attached to a lower limb. The stimulation electrode supporter includes a lower leg stimulation electrode supporter 1 and a thigh stimulation electrode supporter 5.

  The crus stimulation electrode supporter 1 and the thigh stimulation electrode supporter 5 are provided with stimulation electrodes, and can electrically stimulate muscles at a site corresponding to each stimulation electrode. The stimulation electrodes of the lower leg stimulation electrode supporter 1 will be described later with reference to FIG. The thigh stimulation electrode supporter 5 can electrically stimulate the inside and outside of the quadriceps muscle. The main body to which the stimulation electrode of the thigh stimulation electrode supporter 5 is attached is made of plastic, for example.

  The lower leg stimulation electrode supporter 1 can be opened and closed as will be described later with reference to FIG. In the state of FIG. 1, the lower leg stimulation electrode supporter 1 is mounted on the lower leg so that the divided members are integrally wound around the lower leg. Specifically, the fixing bracket 2 and the belt 10 which are fixing means are used, and the belt 10 is inserted through the fixing bracket 2. If a hook-and-loop fastener is used for the belt 10, the belts 10 can be bonded together, and the divided members can be joined by the belt 10.

  A foot switch 3 and a foot pressure sensor 4 which are sensors for detecting leg ground contact information are interposed between the shoe 11 and the back surface of the foot. As the foot pressure sensor 4, for example, a dynamic strain pressure sensor can be used. The foot pressure sensor 4 may estimate the leg contact period by the foot switch 3. Moreover, an ankle joint moment can be estimated.

  Further, an inclination angle sensor 7 is attached to the thigh stimulation electrode supporter 5, and an inclination angle sensor 8 is attached to the waist by a fixing belt 9. As the tilt angle sensors 7 and 8, for example, an acceleration sensor or a gyro sensor can be used. The tilt angle sensors 7 and 8 are sensors for detecting the hip joint angle. In order to control the ankle joint, as shown in FIG. 1, sensors 12 and 13 for detecting the ankle joint angle are provided to measure the ankle joint angle. The knee joint angle can also be measured from the above four sensors 7, 8, 12 and 13.

  FIG. 2 is a view showing the inside of the lower leg stimulation electrode supporter 1. The lower leg stimulation electrode supporter 1 is divided into a first main body 15 and a second main body 16. The 1st main-body part 15 and the 2nd main-body part 16 are solid members, for example, are made of plastics. The lower leg stimulation electrode supporter 1 of FIG. 2 shows a state in which the belt 10 is removed from the fixing bracket 2 from the state of FIG. 1 and the first main body portion 15 and the second main body portion 16 that have been joined are opened. . When a translucent plastic material is used for the first main body portion 15 and the second main body portion 16, the positions of the electrodes are easily understood, and attachment is facilitated.

  An elastic member 17 is combined with the second main body portion 16. The elastic member 17 is made of, for example, cloth. According to this configuration, since the stimulation electrode supporter 1 includes the expansion / contraction member 17, it can be easily attached to a wearer having a different size of the lower limb, and the adhesion to the attachment can be improved.

  A pair of gastrocnemius muscle stimulation electrodes 20 and a pair of soleus muscle stimulation electrodes 21 are attached to the first main body portion 15. A pair of anterior tibial muscle stimulation electrodes 22 are attached to the second main body portion 16. When the lower leg stimulation electrode supporter 1 is attached to the lower leg as shown in FIG. 1, the gastrocnemius muscle stimulation electrode 20 corresponds to the position of the gastrocnemius muscle, and the soleus muscle stimulation electrode 21 corresponds to the position of the soleus muscle. The tibial muscle stimulation electrode 22 corresponds to the position of the anterior tibial muscle. The anterior tibial muscle stimulation electrode 22 also corresponds to the long ankle extensor muscle.

  Lead wires for transmitting a stimulation pattern are attached to the stimulation electrodes 20 to 22. The stimulation electrodes 20 to 22 are preferably formed of flexible members so that the stimulation electrodes 20 to 22 are easy to adjust to the skin and can be deformed flexibly with walking. Examples of the flexible material include silver woven fabric or silver fine wire mesh. The stimulation electrodes 20 to 22 are sized to cover the nerves and muscles of the stimulation site, and cover the muscle belly of each muscle as much as possible. This is useful for reducing the intensity of stimulation and reducing discomfort during stimulation. Moreover, it is preferable that the size of the stimulation electrodes 20 to 22 is a size with a margin in consideration of variation in the size of the stimulation site between wearers. By taking a slightly larger size, the actual stimulation site may be adjusted to the size of each user by adjusting the size of the applied gel.

  In FIG. 2, a recording electrode 23 and a recording electrode 24 are attached to the first main body 15, and a recording electrode 25 is attached to the second main body 16. The recording electrodes 23 to 25 are electrical response measuring sensors, and are electrodes that measure the electrical response from the stimulated muscle. The position of the recording electrode 24 may be arranged toward the lower right side of the stimulation electrode 21 to prevent interference between the recording electrodes. Further, the recording electrode may be provided only on one leg side or on both leg sides.

  FIG. 5 shows a plan view of an example of a recording electrode manufactured as a prototype. The recording electrode is made of a silver plate, and includes three recording electrodes 32, an amplifier common 31 (0 volt) around the recording electrode 32, and an earth 30 surrounding the whole. The dimension a is 10 mm, for example, and the dimension b is 48 mm, for example. Earth is effective in removing stimulus noise.

  A stimulation pattern corresponding to the stimulation site of each electrode is transmitted to each electrode of the lower leg stimulation electrode supporter 1 and the thigh stimulation electrode supporter 5. The created stimulation pattern is transmitted to the crus stimulation electrode supporter 1 and the thigh stimulation electrode supporter 5 by the driving force applying device.

  The driving force application device is included in the functional electrical stimulation system of the present embodiment. These are configured as a control board, for example, stored in a box and attached to the belt 9 shown in FIG.

  The functional electrical stimulation system of this embodiment is based on the detection signals from the foot switch 3 and the foot pressure sensor 4 installed in the shoe 11 of FIG. Is converted into a stimulation pattern corresponding to each muscle. This stimulation pattern is transmitted to the crus stimulation electrode supporter 1 and the thigh stimulation electrode supporter 5 by the driving force applying device.

  As shown in FIG. 2, in the crus stimulation electrode supporter 1, the gastrocnemius muscle stimulation electrode 20, the soleus muscle stimulation electrode 21 and the anterior tibial muscle stimulation electrode 22 are each configured independently. For this reason, with respect to the gastrocnemius, the soleus and the anterior tibial muscle, each muscle can be individually electrically stimulated with the stimulation pattern corresponding to each of these muscles.

  Here, in the past, most of the foot movement control for preventing drooping foot for stroke hemiplegic patients has focused on only the foot movement by stimulating the anterior tibial muscle during the swing phase. On the other hand, the inventor of the present application has focused on that the lower limb driving force of a healthy person at a normal walking speed is mainly due to an ankle joint. Then, we developed a functional electrical stimulation system that adopts an ankle joint drive system that takes into account the movement of the entire lower limbs.

  The crus stimulation electrode supporter 1 as described above is derived by repeating the experiment confirmation by the present inventor with walking training. The inventor of the present application can obtain the driving force of the ankle joint that enables walking close to natural walking by individually stimulating a plurality of main muscles around the ankle joint based on a human passive walking style. I found out. Corresponding to this, the crus stimulation electrode supporter 1 according to the present embodiment is configured with stimulation electrodes so that each muscle can be electrically stimulated individually as described above.

  FIG. 6 shows the body center-of-gravity movement acceleration when walking when the gastrocnemius and soleus muscles are individually stimulated. FIG. 6A shows a stimulation voltage pattern in one stride. A line 35 is a stimulation voltage pattern for the gastrocnemius muscle, and a line 36 is a stimulation voltage pattern for the soleus muscle. FIG. 6B shows an acceleration curve of the body center of gravity. Line 40 is the vertical acceleration when the soleus is electrically stimulated, line 41 is the vertical acceleration when the gastrocnemius is electrically stimulated, line 42 is the acceleration in the traveling direction when the soleus is electrically stimulated, and line 43 is the electric acceleration of the gastrocnemius. The acceleration in the direction of travel when stimulated is shown.

  As can be seen from FIG. 6 (b), the soleus and gastrocnemius muscles act as ankle flexors, but have different effects on the body center of gravity. The soleus has a relatively large forward action. From this, the stimulation pattern transmitted to the gastrocnemius muscle stimulation electrode 20 and the soleus muscle stimulation electrode 21 is individually set, and the gastrocnemius muscle and the soleus muscle are electrically stimulated with separate stimulation patterns, thereby making it closer to natural walking. A possible driving force of the ankle joint is obtained.

  Since the crus stimulation electrode supporter 1 also includes the stimulation electrode 22 corresponding to the anterior tibial muscle as an ankle joint extensor, the rigidity of the joint can be adjusted, which is more advantageous for realizing a more natural walking. Furthermore, the finger extensor muscles may be electrically stimulated together with the anterior tibial muscle.

  In this embodiment, the thigh stimulation electrode supporter 5 is provided as described above, and the quadriceps muscle can be electrically stimulated. Using this thigh stimulation electrode supporter 5, the following electrical stimulation can be performed.

  That is, in one gait cycle, the gastrocnemius muscle stimulation by the crus stimulation electrode supporter 1 in the stance phase was continued until the early swing phase with a stimulus strength that allowed the knee to bend, and the anti-legs entered the stance phase. In the stage, the thigh quadriceps muscle may be electrically stimulated by the thigh stimulation electrode supporter 5. According to this electrical stimulation, when there is an abnormal muscle tension such as spasticity, the knee can be bent in the early swing phase, and the knee can be prevented from bending in the stance phase of the leg. You can prevent it from tripping on the floor.

  A biphasic rectangular wave can be used as a stimulation pulse used for electrical stimulation. FIG. 4 shows a basic stimulus waveform diagram of electrical stimulation. For example, the stimulation waveform is a burst wave, the basic pulse width is 2 to 5 kHz, the stimulation frequency is 20 to 60 Hz, and a voltage control method is adopted, so that excessive current due to impedance variation between skin and electrodes is locally generated. What is necessary is just to prevent flowing. In addition, in the case of the rectangular wave, when the skin feels uncomfortable or painful, the symptoms may be reduced by using a biphasic sine wave of 2 to 5 kHz as the fundamental frequency.

  Furthermore, by setting the stimulation pulse to a biphasic rectangular wave or a biphasic sine wave, one channel output composed of a pair of electrodes can stimulate one or more nerves / muscles simultaneously. For example, the foot can be extended in the sagittal plane by stimulating the anterior tibialis anterior and longus extensor muscles with one electrode.

  The functional electrical stimulation according to the present embodiment adopts an ankle joint drive mode using a mechanism of passive walking, and is based on a property inherent in not only a human but also a mechanical system. It can be said that efficiency is good. Feedback control may be incorporated in order to prevent the applicable range from becoming narrow due to parameter setting restrictions or to deal with disturbances (for example, Patent Document 1 and Non-Patent Document 2).

  In addition, although it is possible to estimate the ankle joint driving force online, a model including a knee / hip joint may be a little burdensome for the portable electrical stimulation device. For this reason, you may obtain | require an ankle joint moment using the existing skeletal model (for example, nonpatent literature 3-5) using the walking speed and ankle joint moment relationship by a healthy person's empirical formula. In this case, based on the obtained ankle joint moment, muscle strength may be estimated by a musculoskeletal mathematical model (for example, Non-Patent Document 6), and the stimulation pattern may be estimated assuming that the muscle strength is proportional to the stimulation voltage.

  FIG. 3 is a perspective view showing an example of a walking state using the functional electrical stimulation system according to the present embodiment. The pedestrian shown in FIG. 3 is wearing the attachment member according to the functional electrical stimulation system according to the present embodiment. Since these are the same configurations as those described with reference to FIGS. 1 and 2, the same numbers are assigned and description thereof is omitted.

  In FIG. 3, the pedestrian wears the lower leg stimulation electrode supporter 1 on the lower leg, the thigh stimulation electrode supporter 5 on the thigh, and the tilt angle sensor 9 by the fixing belt 9 on the waist. It is attached. 3A shows a state in which the right lower limb is kicking out, FIG. 3B shows a state in which the right lower limb is in the early swing phase, and FIG. 3C shows a state in which the right lower limb is in the middle swing phase. Is shown.

  In the functional electrical stimulation system according to the present embodiment, feedback control for stabilizing muscle output may be performed as follows. As shown in FIG. 2, in the crus stimulation electrode supporter 1, recording electrodes 23 to 25 that are electrical response measurement sensors are arranged in the vicinity of the stimulation electrodes 20 to 22. The recording electrodes 23 to 25 are desirably arranged so that mutual interference can be suppressed. Based on the detection signals from the recording electrodes 23 to 25, the muscle output is estimated (refer to Non-Patent Document 8 for the detection / estimation method from one muscle), and feedback control is applied to the stimulation pattern. The arrangement of the stimulation electrodes 20 to 22 shown in FIG. 2 has relatively little mutual interference of response waveforms, and helps to stabilize the torque generated by electrical stimulation.

  Further, feedback control of the hip joint angle may be performed. In this control, the hip joint angle is detected from the detection values of the thigh inclination angle sensor 7 and the waist inclination angle sensor 9. Similarly, feedback control of the ankle joint angle may be performed. A steady walking speed can be maintained by this feedback control.

  As mentioned above, although embodiment of this invention was described, these are examples and may be changed suitably. For example, the configuration of the stimulation electrode is not limited to the example of FIG. 2 and may be more fragmented.

DESCRIPTION OF SYMBOLS 1 Lower leg stimulation electrode supporter 2 Fixing metal fitting 3 Foot switch 4 Foot pressure sensor 5 Thigh stimulation electrode supporter 7, 8 Inclination angle sensor 10 Belt 17 Telescopic binding material 20 Gastrocnemius muscle stimulation electrode 21 Soleus muscle stimulation electrode 22 Anterior tibial muscle Stimulation electrode 23, 24, 25 Recording electrode

Claims (14)

A functional electrical stimulation system for walking support,
A driving force applying device that individually applies electrical stimulation to each of the plurality of muscles in the muscle group around the ankle joint and applies an ankle joint driving force;
A stimulation electrode supporter that is mounted on a lower limb and performs the electrical stimulation;
It has a sensor that detects leg contact information and joint angle.
Based on the detection signal of the sensor, the muscle output is estimated online by a skeletal model of passive walking style and a musculoskeletal mathematical model, and the estimated muscle output is converted into a stimulation pattern corresponding to each muscle,
A functional electrical stimulation system, wherein each muscle is individually electrically stimulated with a stimulation pattern corresponding to each muscle by the stimulation electrode supporter.   The functional electricity according to claim 1, wherein the stimulation electrode supporter is provided with stimulation electrodes corresponding to the gastrocnemius and soleus muscles separately so that the gastrocnemius and soleus muscles as ankle flexor muscles can be electrically stimulated individually. Stimulation system.   The functional electrical stimulation system according to claim 1, wherein the stimulation electrode supporter is provided with a stimulation electrode so that the anterior tibial muscle as an ankle joint extensor can be stimulated.   The stimulation electrode supporter has separate stimulation electrodes for the gastrocnemius, soleus and anterior tibial muscles so that the gastrocnemius, soleus and anterior tibial muscles as ankle extensors can be electrically stimulated individually. The functional electrical stimulation system according to claim 1, wherein the finger extensor muscle can be electrically stimulated together with the anterior tibial muscle.   5. The functional electrical stimulation system according to claim 1, wherein the stimulation electrode supporter is provided with an electrode so as to electrically stimulate the quadriceps muscle that is a knee joint extensor in addition to the muscles of the lower leg. .   In one gait cycle, the gastrocnemius muscle stimulation in the stance phase is continued with a stimulation intensity enough to bend the knee until the early swing phase, and the quadriceps muscles are electrically stimulated when the anti-legged phase is in the stance phase. The functional electrical stimulation system of claim 5, which is capable.   The stimulation pulse of the electrical stimulation is a biphasic rectangular wave or a biphasic sine wave, and one channel output composed of a pair of electrodes can simultaneously stimulate one or more nerves and muscles. 7. The functional electrical stimulation system according to any one of 1 to 6.   The functional stimulation according to any one of claims 1 to 7, wherein the electrical stimulation employs a voltage control method, the stimulation waveform is a burst wave, the basic pulse width is 2 to 5 kHz, and the stimulation frequency is 20 to 60 Hz. Electrical stimulation system.   The functional electrical stimulation system according to any one of claims 1 to 8, wherein the stimulation electrode is formed of a flexible material and has a lead wire attached thereto.   The functional electrical stimulation system according to claim 1, wherein the stimulation electrode supporter is formed by combining a solid member and an elastic member.   The functional electrical stimulation system according to any one of claims 1 to 10, wherein the stimulation electrode supporter is configured to be openable and closable, and includes a fixing unit that is fixed in a closed state when the stimulation electrode supporter is mounted.   The functional electrical stimulation system according to any one of claims 1 to 11, wherein the stimulation electrode supporter has recording electrodes on one leg or both legs, and can record electrical responses of gastrocnemius, soleus and anterior tibial muscles.   The functional electrical stimulation according to any one of claims 1 to 12, wherein a foot switch and a foot pressure sensor are used as sensors for detecting leg ground contact information, and an acceleration sensor or a gyro sensor is used as a sensor for detecting joint angles of feet and hips. system.   The ankle joint moment is estimated online using the skeletal model, or the ankle joint moment is estimated using the relationship between the walking speed and the ankle joint moment based on the empirical formula of a healthy person, and the muscle strength is calculated using the musculoskeletal mathematical model. The functional electrical stimulation system according to claim 1, wherein the stimulation pattern is estimated on the assumption that muscle strength is proportional to a stimulation voltage.

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