Functional electrical stimulation device and functional electrical stimulation system

Abstract

A functional electrical stimulation device (10) includes: four or more conductive wires (12); four or more electrode portions (13) each provided to each of the four or more conductive wires (12) for stimulating four or more upper limb-related nerves constituting a brachial plexus or stimulating four or more lower limb-related nerves located in a cauda equina; and a main body portion (11) for supplying electric current to the four or more electrode portions (13) via the four or more conductive wires (12).

Description

Technical Field

[0001] This invention relates to a functional electrical stimulation device and a functional electrical stimulation system implanted in the human body. Background Technology

[0002] Patent document 1 discloses a technique for stimulating nerves by transmitting stimulation signals transcutaneously or subcutaneously for urination control. Patent document 2 discloses a technique for stimulating nerves by transmitting stimulation signals transcutaneously or subcutaneously for tremor control.

[0003] (Existing technical documents) (Patent Documents) Patent Document 1: Japanese Patent No. 7013023 Patent Document 2: Japanese Patent No. 6507099 Summary of the Invention

[0004] The problem that the invention aims to solve To improve the quality of life for patients suffering from neuromuscular diseases, it is desirable to control their paralyzed upper or lower limbs. However, in order to achieve precise control of the paralyzed upper or lower limbs using the technology disclosed in Patent Document 1 or 2, electrodes for stimulating peripheral nerves need to be implanted separately into each of multiple peripheral nerves that are far apart from each other. This results in an increase in surgical sites, thus placing a greater burden on the patient.

[0005] Therefore, the present invention provides a functional electrical stimulation device and a functional electrical stimulation system that can both reduce the burden on the human body caused by surgical invasiveness and stimulate nerves.

[0006] Methods for solving problems The functional electrical stimulation device involved in this invention is an implantable functional electrical stimulation device in the human body, comprising: four or more wires; four or more electrode portions respectively disposed on each of the four or more wires for stimulating four or more upper limb related nerves constituting the brachial plexus or stimulating four or more lower limb related nerves located in the cauda equina; and a main body portion that supplies current to the four or more electrode portions via the four or more wires.

[0007] The functional electrical stimulation system of the present invention comprises: the functional electrical stimulation device described above; a brain-computer interface implanted in the human body; and an external device capable of wirelessly communicating with the functional electrical stimulation device and the brain-computer interface.

[0008] Furthermore, these general or specific methods can be implemented through systems, methods, integrated circuits, computer programs, or recording media such as computer-readable CD-ROMs, or through any combination of systems, methods, integrated circuits, computer programs, and recording media.

[0009] The effects of the invention The functional electrical stimulation device, etc., according to one aspect of the present invention can both reduce the burden on the human body caused by surgical invasiveness and stimulate nerves. Attached Figure Description

[0010] Figure 1A This is a structural diagram illustrating an example of a functional electrical stimulation device according to an embodiment.

[0011] Figure 1B This is a structural diagram illustrating another example of a functional electrical stimulation device according to an embodiment.

[0012] Figure 2 This is a structural diagram illustrating an example of a functional electrical stimulation system according to an embodiment.

[0013] Figure 3A This is a diagram illustrating an example of a cuff electrode section according to an embodiment.

[0014] Figure 3B This is a diagram showing an example of a cuff-type electrode portion according to an embodiment.

[0015] Figure 4A This is a diagram illustrating an example of a spiral electrode section according to an embodiment.

[0016] Figure 4B This is a diagram showing an example of a spiral electrode section according to an embodiment.

[0017] Figure 5 This diagram illustrates how a specific muscle can be selectively contracted by using the functional electrical stimulation device described in the embodiment. Detailed Implementation

[0018] The embodiments will now be described in detail with reference to the accompanying drawings.

[0019] Furthermore, the embodiments described below are merely general or specific examples. The numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, and connection methods shown in the following embodiments are only examples and are not intended to limit the present invention.

[0020] (Implementation Method) The functional electrical stimulation device and functional electrical stimulation system involved in the embodiments will be described below.

[0021] Figure 1A This is a structural diagram showing an example of the functional electrical stimulation device 10 according to the embodiment.

[0022] Figure 1B This is a structural diagram illustrating another example of the functional electrical stimulation device 10 according to the embodiment.

[0023] like Figure 1A and Figure 1B As shown, the functional electrical stimulation device 10 is an implantable device in the human body. The functional electrical stimulation device 10 is a device for performing functional electrical stimulation (FES). FES is performed with the aim of restoring motor function by inducing muscle contraction through electrical stimulation. Although FES typically involves direct electrical stimulation of muscles, the FES of this invention is characterized by inducing muscle contraction and restoring motor function with minimal surgical invasiveness by stimulating the proximal end of peripheral nerves.

[0024] For example, in the case of controlling the upper limb, although the functional electrical stimulation device 10, such as Figure 1A As shown, it can be implanted subcutaneously in the armpit, but it can also be implanted subcutaneously in the upper arm. Furthermore, for example, in cases where the lower limbs are controlled, the functional electrical stimulation device 10, such as... Figure 1B As shown, the implant is placed in the lower back of the person. Figure 1A and Figure 1B As shown, the functional electrical stimulation device 10 includes: four or more wires 12; four or more electrode portions 13, each disposed on one of the four or more wires 12; and a main body 11 that supplies current to the four or more electrode portions 13 via the four or more wires 12. For example, an electrode portion 13 is disposed at the tip of each of the four or more wires 12. For example, the length of each of the four or more wires 12 is 20 cm or less, preferably 15 cm or less. The four or more electrode portions 13 are used to stimulate four or more upper limb-related nerves constituting the brachial plexus or to stimulate four or more lower limb-related nerves located in the cauda equina. For example, by applying a pulse signal such as 50 Hz to each nerve and allowing a current of about 1 to 4 mA to flow through it, each nerve is stimulated, and the muscles innervated by that nerve contract.

[0025] For example, the main body 11 can selectively supply current to each of the four or more electrode sections 13. By selectively supplying current to each of the four or more electrode sections 13, it is possible to selectively stimulate four or more upper limb-related nerves or four or more lower limb-related nerves respectively. Therefore, fine motor control of the upper or lower limbs can be achieved.

[0026] For example, the main body 11 may have a wireless interface, and can supply current to four or more electrode sections 13 based on signals received via the wireless interface. Therefore, since signals for controlling the upper or lower limbs can be received wirelessly with an external device (such as the EEG interpretation device 100 described later), the risk of infection can be reduced compared to the case where the internal functional electrical stimulation device 10 is connected to an external device via a wire. Furthermore, for example, the main body 11 can selectively supply current to each of the four or more electrode sections 13 by receiving instructions from an external device to supply current to a specific electrode section 13 among the four or more electrode sections 13.

[0027] For example, the main body 11 may also have a wireless interface with wireless charging functionality. For example, wireless charging can be achieved through a loop antenna or the like. Thus, the functional electrical stimulation device 10 implanted in the body can be charged without contact.

[0028] For example, in the case of controlling the upper limbs, such as Figure 1A As shown, four or more wires 12 can be replaced by five wires 12, and four or more electrode portions 13 can be replaced by five electrode portions 13. These five electrode portions 13 can be used to stimulate five upper limb-related nerves. The upper limb is innervated by five nerves originating from the brachial plexus: the median nerve, radial nerve, musculocutaneous nerve, axillary nerve, and ulnar nerve (hereinafter referred to as upper limb-related nerves). Therefore, the functional electrical stimulation device 10 can also be used to stimulate these five upper limb-related nerves. For example, by making only a single skin incision under the armpit, the electrode portions 13 can be installed on the five upper limb-related nerves, thereby reducing surgical invasiveness and complexity while enabling precise control of the movement of the entire upper limb.

[0029] For example, in situations where the lower limbs are controlled, such as Figure 1BAs shown, four or more wires 12 can be four wires 12, and four or more electrode portions 13 can be four electrode portions 13. The four electrode portions 13 can be used to stimulate four lower limb-related nerves. The walking function of the lower limbs is mainly controlled at the L4 and L6 levels. Therefore, the functional electrical stimulation device 10 can also be a device for stimulating four lower limb-related nerves located in the cauda equina, specifically the left L4 anterior root, left L6 anterior root, right L4 anterior root, and right L6 anterior root. For example, the electrode portions 13 can be installed on the four lower limb-related nerves by making a single incision in the lumbar region (e.g., around the iliac crest), thereby reducing surgical invasiveness and complexity while still controlling the movement of the lower limbs required for walking. Furthermore, in the cauda equina, the anterior and posterior root components of the spinal nerves are not mixed, so the electrode portions 13 can be installed only on the anterior root component of the anterior and posterior root components. By installing electrode portion 13 only on the anterior root component, it is possible to selectively apply electrical stimulation only to motor nerves, thereby avoiding stimulation of sensory nerves and enabling motor control without producing discomfort caused by sensory stimulation.

[0030] Figure 2 This is a structural diagram illustrating an example of the functional electrical stimulation system 1 according to the embodiment.

[0031] like Figure 2 As shown, for example, the functional electrical stimulation system 1 includes a functional electrical stimulation device 10, an electroencephalogram (EEG) machine 200, and an EEG interpretation device 100.

[0032] The electroencephalogram (EEG) machine 200 is an example of a brain-computer interface (BMI) implanted in the human body. The main body of the EEG machine 200 is implanted subcutaneously in the head, while the electrodes remain on the surface of the brain, accurately acquiring brainwave signals from within the skull. For example, the EEG machine 200 is wirelessly connected to a brainwave interpretation device 100, thereby transmitting the acquired brainwave signals from the EEG machine 200 to the brainwave interpretation device 100.

[0033] The EEG interpretation device 100 is an example of an external device capable of wirelessly communicating with the functional electrical stimulation device 10 and the BMI (electroencephalogram 200). The EEG interpretation device 100 interprets the intentions of a person with the EEG 200 installed from brainwave signals. Specifically, the EEG interpretation device 100 interprets what kind of movement the person is attempting and sends a signal corresponding to the interpretation result to the functional electrical stimulation device 10.

[0034] For example, when the EEG interpretation device 100 interprets from the EEG signals that a person is attempting to clench their right hand, it generates a signal to stimulate the relevant nerves of the upper limb necessary to make the right hand clench, and sends it to the functional electrical stimulation device 10. The signal for stimulating the relevant nerves of the upper limb is, for example, a signal instructing which electrode 13 of the five electrode sections 13 to apply a certain amount of current. Furthermore, as described later, the signal for stimulating the relevant nerves of the upper limb may also be a signal further instructing which electrode of the plurality of electrodes disposed on the electrode section 13 to apply current.

[0035] Since the characteristics of brainwaves differ for each type of movement a person attempts to perform, a trained model that learns the relationship between the content of the movement and the characteristics of the brainwaves can be prepared and stored in the memory of the brainwave interpretation device 100. For example, the brainwave interpretation device 100 can interpret what kind of movement a person is attempting by inputting the acquired brainwave signals into the trained model. Furthermore, since it is possible to predetermine which electrode in which electrode section 13 will be applied and how much current will be applied to induce which type of movement, a table can be prepared that corresponds to the content of the movement, the electrode section 13 in which current flows (further including multiple electrodes in the electrode section 13), and the amount of current flowing, and this table can be stored in the memory of the brainwave interpretation device 100. Therefore, the EEG interpretation device 100 is able to determine which of the four or more electrode portions 13 (and further, which of the multiple electrodes provided in the electrode portion 13) should be applied with how much current in order to enable a person's muscles to perform the interpreted movement, and is able to instruct the functional electrical stimulation device 10 to apply the determined amount of current to the determined electrode portion 13.

[0036] In this way, by implanting a BMI device, consisting of an electroencephalogram (EEG) machine 200, into the human body, it is possible to control the upper or lower limbs by causing the paralyzed upper or lower limbs to perform specific movements when the person has the intention to perform a specific movement.

[0037] The details of electrode section 13 will be explained next.

[0038] For example, each of the four or more electrode sections 13 has multiple electrodes and a structure capable of being wrapped around each of four or more upper limb-related nerves or each of four or more lower limb-related nerves. When each of the four or more electrode sections 13 is wrapped around each of the four or more upper limb-related nerves or each of the four or more lower limb-related nerves, the multiple electrodes are arranged along the extension direction of the wrapped upper limb-related nerve or lower limb-related nerve. For example, there are two types of electrode sections 13: cuff-type electrode sections 13 and spiral-type electrode sections 13. First, the cuff-type electrode section 13 will be described.

[0039] Figure 3A and Figure 3B This is a diagram showing an example of a cuff-type electrode section 13 according to an embodiment.

[0040] For example, structures capable of wrapping around nerves can be such as Figure 3A The plate-like structure shown has a coiled shape. Each of the four or more plate-like electrode portions 13 is coiled in such a way that it covers each of the four or more upper limb-related nerves or each of the four or more lower limb-related nerves, thereby remaining in each of the four or more upper limb-related nerves or each of the four or more lower limb-related nerves.

[0041] For example, along the nerve Figure 3A When the electrode portion 13 extends in the left and right directions, it is made to extend along the left and right directions. Figure 3A The electrode portion 13 is bent in the vertical direction so that it wraps around the nerve in a way that covers the nerve. Figure 3B This is a diagram showing the electrode portion 13 wrapped around the nerve when viewed from the direction of nerve extension.

[0042] For example, such as Figure 3A As shown, the cuff-type electrode section 13 has multiple electrodes 13a to 13l. (As...) Figure 3A As shown, multiple electrodes 13a to 13c are arranged along the nerve's extension direction when the electrode portion 13 is wrapped around the nerve. Similarly, multiple electrodes 13d to 13f, multiple electrodes 13g to 13i, and multiple electrodes 13j to 13l are also arranged along the nerve's extension direction when the electrode portion 13 is wrapped around the nerve. Figure 3B In the process, electrodes 13b and 13a are arranged behind electrode 13c, electrodes 13e and 13d are arranged behind electrode 13f, electrodes 13h and 13g are arranged behind electrode 13i, and electrodes 13k and 13j are arranged behind electrode 13l.

[0043] For example, when it is necessary to stimulate the area surrounding electrodes 13a to 13c in order to achieve a specific movement, by applying a voltage to electrodes 13a to 13c, making electrodes 13a and 13c have a positive potential and electrode 13b has a negative potential, current can flow from electrode 13a to electrode 13b, and from electrode 13c to electrode 13b. Thus, the current distribution in the nerve can be localized through so-called triphasic stimulation.

[0044] Next, the spiral electrode section 13 will be described.

[0045] Figure 4A and Figure 4B This is a diagram showing an example of the spiral electrode section 13 according to the embodiment.

[0046] For example, structures capable of wrapping around nerves can be such as Figure 4A The linear structure shown. Each of the four or more linear electrode portions 13 is as follows: Figure 4A As shown, it is spirally wrapped around each of four or more upper limb related nerves or each of four or more lower limb related nerves. Figure 4B This is a diagram showing the electrode portion 13 wrapped around the nerve when viewed from the direction of nerve extension. Because the electrode portion 13 is spiral-shaped, it is less likely to detach from the nerve.

[0047] For example, such as Figure 4A As shown, the spiral electrode section 13 has multiple electrodes 13m to 13t. (As...) Figure 4A As shown, multiple electrodes 13m and 13n are arranged along the nerve's extension direction when the electrode portion 13 is wrapped around the nerve. Similarly, multiple electrodes 13o and 13p, multiple electrodes 13q and 13r, and multiple electrodes 13s and 13t are also arranged along the nerve's extension direction when the electrode portion 13 is wrapped around the nerve. Figure 4B In the process, an electrode 13m is provided behind the electrode 13n, an electrode 13o is provided behind the electrode 13p, an electrode 13q is provided behind the electrode 13r, and an electrode 13s is provided behind the electrode 13t.

[0048] For example, when it is necessary to stimulate the area around electrodes 13m and 13n in order to achieve a specific movement, by applying a voltage to electrodes 13m and 13n, making electrode 13m a positive potential and electrode 13n a negative potential, current can flow from electrode 13m to electrode 13n.

[0049] In this way, by arranging multiple electrodes along the extension direction of the relevant nerves in the upper or lower limbs, local stimulation of the relevant nerves in the upper or lower limbs can be achieved. Therefore, fine motor control of the upper or lower limbs can be realized.

[0050] Next, using Figure 5 This demonstrates that stimulating nerves can selectively cause specific muscles to contract.

[0051] Figure 5 These are diagrams illustrating how the functional electrical stimulation device 10 according to the embodiments enables the selective contraction of specific muscles. The horizontal axis of each diagram represents the amount of electrical current flowing in the nerve, and the vertical axis represents the amount of muscle contraction.

[0052] like Figure 5 As shown in the previous paragraph, stimulation of the radial nerve primarily induces contraction of the triceps brachii muscle. Furthermore, as... Figure 5 As shown in the middle section, it can be demonstrated that stimulating the axillary nerve primarily causes the deltoid muscle to contract. Furthermore, as... Figure 5 As shown in the following paragraph, it can be seen that stimulating the musculocutaneous nerve can primarily cause the superficial flexor digitorum muscles to contract.

[0053] As described above, the functional electrical stimulation device 10 according to the present invention can stimulate four or more upper limb-related nerves constituting the brachial plexus or stimulate four or more lower limb-related nerves located in the cauda equina. Since the brachial plexus contains upper limb-related nerves for precise control of the upper limbs, by implanting the functional electrical stimulation device 10 near the brachial plexus via a single surgical approach (i.e., a less invasive surgical method), four or more electrode portions 13 can be installed on four or more upper limb-related nerves, thereby reducing the burden on the body caused by surgical invasiveness. Furthermore, since the cauda equina contains lower limb-related nerves for control of the lower limbs, by implanting the functional electrical stimulation device 10 near the cauda equina via a single surgical approach (i.e., a less invasive surgical method), four or more electrode portions 13 can be installed on four or more lower limb-related nerves, thereby reducing the burden on the body caused by surgical invasiveness. Furthermore, since four or more upper limb-related nerves or four or more lower limb-related nerves are clustered together, the wires 12 used to supply current to the electrode portions 13 installed on each nerve can be shortened to less than 15 cm, thereby reducing the number of foreign objects implanted in the body.

[0054] Since peripheral nerves branch out into multiple distal branches, installing electrodes on all branches would increase the number of surgical incisions, placing a significant burden on the body due to surgical invasiveness. The functional electrical stimulation device 10 of the present invention, however, can reduce the burden of surgical invasiveness while simultaneously stimulating the nerves. Furthermore, individuals with the implanted functional electrical stimulation device 10 can control their paralyzed upper or lower limbs, thus improving their quality of life.

[0055] (Other implementation methods) As described above, the embodiments have been presented as examples of the technology involved in this invention. However, the technology involved in this invention is not limited thereto, and is also applicable to embodiments with appropriate changes, substitutions, additions, omissions, etc. For example, the following variation is also included in one embodiment of this invention.

[0056] For example, in the above embodiment, an example was described where the main body 11 of the functional electrical stimulation device 10 has a wireless interface, but the main body 11 of the functional electrical stimulation device 10 may also not have a wireless interface. For example, communication or charging may also be performed via a wired connection.

[0057] For example, in the above embodiment, an example was described in which the plurality of electrodes of the electrode section 13 are arranged along the extension direction of the nerve; however, the plurality of electrodes of the electrode section 13 may also be arranged not along the extension direction of the nerve. Furthermore, Figures 3A to 4B The number of electrodes in the electrode section 13 shown is only one example; there may be more or fewer electrodes. Figures 3A to 4B The quantity shown.

[0058] For example, in the above embodiment, examples of four or more wires 12 are described, which are either four wires 12 or five wires 12, but four or more wires 12 can also be six or more wires 12. Similarly, four or more electrode portions 13 can also be six or more electrode portions 13.

[0059] Furthermore, this invention also includes various modifications to the implementation methods that can be conceived by those skilled in the art, as well as methods that arbitrarily combine the constituent elements and functions of each implementation method without departing from the spirit of this invention.

[0060] (Postscript) Based on the above description of the embodiments, the following technology is disclosed.

[0061] (Technology 1) A functional electrical stimulation device implanted in the human body, comprising: four or more wires; four or more electrode portions respectively disposed on each of the four or more wires for stimulating four or more upper limb related nerves constituting the brachial plexus or stimulating four or more lower limb related nerves located in the cauda equina; and a main body portion for supplying current to the four or more electrode portions via the four or more wires.

[0062] Because peripheral nerves branch out into multiple distal segments, installing electrodes on all branches would increase the number of surgical incisions, resulting in a greater surgical burden on the body. In contrast, the functional electrical stimulation device according to the present invention can stimulate four or more upper limb-related nerves constituting the brachial plexus or four or more lower limb-related nerves located in the cauda equina. Since the brachial plexus contains upper limb-related nerves for precise control of the upper limbs, by implanting the functional electrical stimulation device near the brachial plexus (i.e., a less invasive surgical approach), four or more electrode sites can be installed on four or more upper limb-related nerves, thereby reducing the burden on the body caused by surgical invasiveness. Furthermore, since the cauda equina contains lower limb-related nerves for control of the lower limbs, by implanting the functional electrical stimulation device near the cauda equina (i.e., a less invasive surgical approach), four or more electrode sites can be installed on four or more lower limb-related nerves, thereby reducing the burden on the body caused by surgical invasiveness. Furthermore, since four or more upper limb-related nerves or four or more lower limb-related nerves are clustered together, the wires used to supply current to the electrodes implanted in each nerve can be shortened, thereby reducing the number of foreign bodies implanted in the body. Thus, the functional electrical stimulation device according to the present invention can both reduce the burden on the body caused by surgical invasiveness and stimulate the nerves. In addition, people with implanted functional electrical stimulation devices can control their paralyzed upper or lower limbs, improving their quality of life.

[0063] (Technology 2) The functional electrical stimulation device as described in Technology 1, wherein the main body selectively supplies current to each of the four or more electrode portions.

[0064] Therefore, by selectively supplying current to each of the four or more electrode portions, it is possible to selectively stimulate four or more upper limb-related nerves or four or more lower limb-related nerves respectively. Thus, fine motor control of the upper or lower limbs can be achieved.

[0065] (Technology 3) The functional electrical stimulation device as described in Technology 1 or 2, wherein the main body has a wireless interface and supplies current to the four or more electrode portions based on signals received via the wireless interface.

[0066] Therefore, since it can receive signals for controlling the upper or lower limbs through wireless communication with external devices, the risk of infection can be reduced compared to the case where internal functional electrical stimulation devices are connected to external devices via wires.

[0067] (Technology 4) The functional electrical stimulation device according to any one of Technologies 1 to 3, wherein the main body has a wireless interface with wireless charging function.

[0068] This enables non-contact charging of implanted functional electrical stimulation devices.

[0069] (Technology 5) The functional electrical stimulation device according to any one of Technologies 1 to 4, wherein each of the four or more electrode portions has a plurality of electrodes and a structure capable of being wrapped around each of the four or more upper limb related nerves or each of the four or more lower limb related nerves, wherein the plurality of electrodes are arranged along the extension direction of the wrapped upper limb related nerve or lower limb related nerve when each of the four or more electrode portions is wrapped around each of the four or more upper limb related nerves or each of the four or more lower limb related nerves.

[0070] Therefore, by arranging multiple electrodes along the extension direction of the relevant nerves in the upper or lower limbs, local stimulation of the relevant nerves in the upper or lower limbs can be achieved. This enables fine motor control of the upper or lower limbs.

[0071] (Technology 6) The functional electrical stimulation device as described in Technology 5, wherein the structure is a plate-like structure, each of the four or more plate-like electrode portions is wrapped around each of the four or more upper limb related nerves or each of the four or more lower limb related nerves, thereby remaining in each of the four or more upper limb related nerves or each of the four or more lower limb related nerves.

[0072] In this way, the electrode part can also be a cuff type.

[0073] (Technology 7) The functional electrical stimulation device as described in Technology 5, wherein the structure is a linear structure, and each of the four or more linear electrode portions is spirally wound around each of the four or more upper limb related nerves or each of the four or more lower limb related nerves.

[0074] In this way, the electrode portion can also be spiral-shaped. Furthermore, because the electrode portion is spiral-shaped, it is less likely to fall off the nerve.

[0075] (Technology 8) The functional electrical stimulation device according to any one of Technologies 1 to 7, wherein the length of each of the four or more wires is less than 20 cm.

[0076] In this way, since four or more upper limb related nerves or four or more lower limb related nerves are clustered together, the length of the wire used to supply current to the electrode part installed on each nerve can be shortened to less than 20cm, thereby reducing the number of foreign objects implanted in the body.

[0077] (Technology 9) The functional electrical stimulation device as described in Technology 8, wherein the length of each of the four or more wires is less than 15 cm.

[0078] In this way, since four or more upper limb related nerves or four or more lower limb related nerves are clustered together, the length of the wire used to supply current to the electrode part installed in each nerve can be shortened to less than 15cm, thereby further reducing the foreign body implanted in the body.

[0079] (Technology 10) The functional electrical stimulation device as described in any one of Technologies 1 to 9, wherein the four or more wires are five wires and the four or more electrode portions are five electrode portions, for stimulating five upper limb related nerves.

[0080] Thus, functional electrical stimulation devices can also be used to stimulate the five upper limb-related nerves that constitute the brachial plexus. These five nerves are the median nerve, radial nerve, musculocutaneous nerve, axillary nerve, and ulnar nerve. For example, electrodes can be implanted into these five nerves through a single incision in the armpit, thereby reducing surgical invasiveness and complexity while enabling fine motor control of the upper limb.

[0081] (Technology 11) The functional electrical stimulation device as described in any one of Technologies 1 to 9, wherein the four or more wires are four wires and the four or more electrode portions are four electrode portions for stimulating four lower limb related nerves.

[0082] Thus, the functional electrical stimulation device can also be used to stimulate the four lower limb-related nerves located in the cauda equina: the left L4 anterior root, the left L6 anterior root, the right L4 anterior root, and the right L6 anterior root. For example, electrodes can be implanted into the four lower limb-related nerves through a single incision in the lumbar region, thereby reducing surgical invasiveness and complexity while still achieving motor control of the lower limbs. Furthermore, in the cauda equina, the anterior and posterior root components of the spinal nerves are not mixed, so electrodes can be implanted only into the anterior root component. By implanting electrodes only into the anterior root component, selective electrical stimulation of only the motor nerves can be achieved, thereby avoiding stimulation of the sensory nerves and enabling motor control without causing discomfort due to sensory stimulation.

[0083] (Technology 12) A functional electrical stimulation system comprising: a functional electrical stimulation device as described in any one of Techniques 1 to 11; a brain-computer interface implanted in the human body; and an external device capable of wirelessly communicating with the functional electrical stimulation device and the brain-computer interface.

[0084] Therefore, it is possible to provide a functional electrical stimulation system that can both reduce the burden of surgical invasiveness on the human body and stimulate the nerves. For example, by installing a brain-computer interface such as an electroencephalogram (EEG) device in a person's brain, it is possible to control the upper or lower limbs by causing the paralyzed upper or lower limbs to perform specific movements when the person expresses the intention to perform a specific movement.

[0085] Industrial availability This invention is applicable to devices for electrically stimulating nerves.

[0086] Symbol Explanation 1. Functional electrical stimulation system 10 Functional electrical stimulation devices 11 Main Body 12 wires 13 Electrode section Electrodes 13a to 13t 100 Brainwave Interpretation Device 200 EEG machines

Claims

1. A functional electrical stimulation device implanted in the human body, comprising: Four or more wires; Four or more electrode portions are respectively disposed on each of the four or more wires, for stimulating four or more upper limb-related nerves constituting the brachial plexus or stimulating four or more lower limb-related nerves located in the cauda equina; and The main body supplies current to the four or more electrode sections via the four or more wires.

2. The functional electrical stimulation device as described in claim 1, The main body selectively supplies current to each of the four or more electrode sections.

3. The functional electrical stimulation device as described in claim 1, The main body has a wireless interface and supplies current to the four or more electrode sections based on signals received via the wireless interface.

4. The functional electrical stimulation device as described in claim 1, The main body has a wireless interface with wireless charging function.

5. The functional electrical stimulation device as described in claim 1, Each of the four or more electrode portions has multiple electrodes and a structure capable of wrapping around each of the four or more upper limb-related nerves or each of the four or more lower limb-related nerves. When the multiple electrodes are wrapped around each of the four or more electrode portions of each of the four or more upper limb-related nerves or each of the four or more lower limb-related nerves, they are arranged along the extension direction of the wrapped upper limb-related nerve or lower limb-related nerve.

6. The functional electrical stimulation device as described in claim 5, The structure is a plate-like structure. Each of the four or more plate-shaped electrode portions is wrapped around each of the four or more upper limb-related nerves or each of the four or more lower limb-related nerves, thereby remaining in each of the four or more upper limb-related nerves or each of the four or more lower limb-related nerves.

7. The functional electrical stimulation device as described in claim 5, The structure is a linear structure. Each of the four or more linear electrode portions is spirally wound around each of the four or more upper limb-related nerves or each of the four or more lower limb-related nerves.

8. The functional electrical stimulation device as described in claim 1, The length of each of the four or more wires is less than 20cm.

9. The functional electrical stimulation device as described in claim 8, The length of each of the four or more wires is less than 15cm.

10. The functional electrical stimulation device as described in any one of claims 1 to 9, The term "four or more wires" refers to five wires. The four or more electrode sections are five electrode sections, used to stimulate five related nerves of the upper limb.

11. The functional electrical stimulation device as described in any one of claims 1 to 9, The term "four or more wires" refers to four wires. The four or more electrode sections refer to four electrode sections used to stimulate four related nerves in the lower limbs.

12. A functional electrical stimulation system, comprising: The functional electrical stimulation device according to any one of claims 1 to 9; Brain-computer interface implanted in the human body; and An external device capable of wirelessly communicating with the functional electrical stimulation device and the brain-computer interface.

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