JP2011177297A - Electrostimulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To downsize an external feeder for supplying power to an electrostimulator. <P>SOLUTION: The electrostimulator has a body block including: a stimulation circuit block having a stimulation electrode for stimulating nerves or the like, and an electronic circuit for applying stimulation signals to the stimulation electrode; and a support for holding an implantation position inside the living body of the stimulation electrode. Then, the electrostimulator has a fixture which includes a coil part for performing power supply and/or communication to/with the electronic circuit correspondingly to electromagnetic waves oscillated from an external device and is provided to the proximal end part of the body block. The electronic circuit and the coil part are connected by a conductor, and at least a part of the conductor is formed into a spiral shape so as to be expanded and contracted. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electrical stimulation device that electrically stimulates a living body, and more particularly to an electrical stimulation device that is used by being completely implanted in a living body.

  At present, pain is alleviated by electrical stimulation of nerves when it is not effective in conventional drug therapy, nerve block therapy or surgical therapy, or when the treatment cannot be continued due to side effects. Electrical stimulation therapy is effective. Spinal cord electrical stimulation therapy, which is one type of electrical stimulation therapy, is a stimulation therapy that electrically stimulates the spinal cord in order to relieve pain transmitted to the brain through the spinal cord.

  In spinal cord electrical stimulation therapy, a trial period of 24 hours to several weeks is usually provided in order to confirm the effectiveness of pain relief by electrical stimulation. In the trial period, a stimulation electrode is generally placed in the epidural space outside the spinal dura covering the spinal cord by puncturing from the back side, and then the electrode lead including the stimulation electrode is connected to an external stimulation device. Connect to examine pain relief under various stimulation patterns. During this period, the electrical stimulation device is not implanted. Only when a predetermined effect is recognized during the trial period, the electrical stimulation device is implanted.

  When implanting an electrical stimulation device, the electrode lead placed during the trial period is removed, and then a new stimulation electrode is placed again in the epidural space, and the electrode lead containing this stimulation electrode is transferred to the subcutaneous tunnel. Is guided to the waist, abdomen, or chest. Then, the electrode lead is connected to the electrical stimulation device and implanted subcutaneously.

  By the way, in the trial period in spinal cord electrical stimulation therapy, because the electrode lead is connected to an external electrical stimulation device, the risk of infection, the limitation of the patient's activity, or the limitation of this activity becomes stress. There was a problem of affecting the effectiveness of pain relief.

  On the other hand, the technique described in Patent Document 1 discloses a leadless micro stimulator having electrodes at both ends of a housing, and the risk of infection by implanting the micro stimulator near a nerve. It has become possible to reduce the restriction of patient activity as much as possible.

US Pat. No. 5,193,539

  However, the micro stimulator described in Patent Document 1 includes a coil inside, and obtains electric power by electromagnetic induction with a coil placed outside the body. Therefore, when the micro stimulator is placed in a deep lumen, for example, in the epidural space generally about 5 cm deep from the skin, a large amount of power is placed outside the body to obtain the desired power. The transmission from the coil had to be performed, and an increase in the size of the power feeding device including the extracorporeal coil was a problem. In addition, since it is difficult to know the three-dimensional position and direction of the coil of the micro stimulator in the epidural space, it is difficult to align the axis of the coil placed outside the body and the coil inside the device, Efficient power supply and communication were difficult.

  The present invention has been made in view of this point, and can reduce the size of an external power supply device that can supply power and communicate even in a lumen such as an epidural space, and can be used for power supply. An object of the present invention is to provide an electrical stimulator capable of performing the above.

  It is formed in a rod shape that can be bent and deformed, and is implanted in a living body. A stimulation circuit block having a stimulation electrode for stimulating nerves or muscles in a living body, an electronic circuit electrically connected to the stimulation electrode and applying a stimulation signal to the stimulation electrode, and a stimulation circuit block connected to the stimulation circuit block A body block including a support for holding the implantation position of the electrode in the living body. Furthermore, a fixing device is provided that includes a coil unit that supplies power and / or communication to an electronic circuit in response to electromagnetic waves oscillated from an external device, and is provided at the base end of the main body block. The electronic circuit and the coil portion are connected by a conductive wire, and at least a part of the conductive wire is formed in a spiral shape so as to be expandable and contractible.

  When the electronic circuit includes a secondary battery that can be charged by power feeding from the main body side coil section, the stimulation signal can be generated using the power stored in the secondary battery. On the other hand, when the electronic circuit includes a capacitor capable of storing electricity by feeding from the main body side coil portion, the stimulation signal can be generated using the power stored in the capacitor.

  According to the above-described configuration of the present invention, a part of the conducting wire is formed in a spiral shape so that it can be expanded and contracted, so that the length of the conducting wire can be adjusted in the axial direction of the body block. Thereby, the fixture including the coil part connected to the conducting wire can be arranged so as to be continuous with the base end part of the main body block, and when the electrical stimulation device is completely implanted in the body, the coil surface of the coil part is The coil portion can be arranged near the body surface so as to be substantially parallel to the body surface.

  ADVANTAGE OF THE INVENTION According to this invention, the axis | shaft of the coil of the external apparatus which oscillates electromagnetic waves to a coil part, and the axis | shaft of a coil part can be match | combined easily. Thereby, efficient power feeding and communication can be easily performed. As a result, the controller (external device) that oscillates electromagnetic waves with respect to the coil can be reduced in size.

It is a perspective view showing the whole electrical stimulation device concerning one embodiment of the present invention. It is an exploded appearance figure showing the whole electrical stimulation device concerning one embodiment of the present invention. (A) It is an enlarged view which shows the main body block which concerns on one Embodiment of this invention. (B) It is sectional drawing of the axial direction of the main body block which concerns on one Embodiment of this invention. (A)-(f) It is sectional drawing of the radial direction of the main body block which concerns on one Embodiment of this invention. (A) It is an enlarged view which shows the fixing tool concerning one Embodiment of this invention. (B) It is sectional drawing of the axial direction of the fixing tool concerning one Embodiment of this invention. (C) It is the enlarged view of the upper surface which looked at the fixing tool concerning one Embodiment of this invention from the base end part side. (D) It is the enlarged view of the bottom face which looked at the fixing tool concerning one Embodiment of this invention from the front-end | tip part side. It is a block diagram centering on the stimulation circuit of the electrical stimulation apparatus which concerns on one Embodiment of this invention. It is explanatory drawing for demonstrating the procedure which implants the electrical stimulation apparatus which concerns on one Embodiment of this invention in the biological body. It is explanatory drawing for demonstrating the procedure which implants the electrical stimulation apparatus which concerns on one Embodiment of this invention in the biological body. It is explanatory drawing for demonstrating the procedure which implants the electrical stimulation apparatus which concerns on one Embodiment of this invention in the biological body. It is explanatory drawing for demonstrating the procedure which implants the electrical stimulation apparatus which concerns on one Embodiment of this invention in the biological body. It is explanatory drawing for demonstrating the procedure which implants the electrical stimulation apparatus which concerns on one Embodiment of this invention in the biological body. It is explanatory drawing for demonstrating the procedure which implants the electrical stimulation apparatus which concerns on one Embodiment of this invention in the biological body.

  Embodiments for carrying out the present invention will be described below. The embodiments described below are preferable specific examples of the present invention. Therefore, various technically preferable limitations are attached. However, the present invention is not limited to these forms unless otherwise specified in the following description. For example, the numerical conditions of each parameter given in the following description are only suitable examples, and the dimensions, shapes, and arrangement relationships in the drawings used for the description are also schematic.

The description will be made in the following procedure.
<First embodiment>
1. 1. Configuration of electrical stimulation device 2. Configuration of stimulation circuit, etc. Implanting procedure of electrical stimulation device <Modification>

<One Embodiment of the Present Invention>
An example of an embodiment of the present invention will be described with reference to FIGS.
[1. Configuration of electrical stimulation device]
First, a rough configuration of an electrical stimulation device according to an embodiment will be described with reference to FIGS. 1 and 2.
FIG. 1 is a perspective view showing an entire electrical stimulation apparatus according to an embodiment.
FIG. 2 is an exploded external view of the electrical stimulation apparatus shown in FIG. 1 as viewed from above.

  The electrical stimulation device 101 is formed in a substantially cylindrical shape that can be bent and deformed, generates an electrical stimulation signal, and stimulates nerves and the like in the living body with the stimulation signal. The electrical stimulation device 101 is implanted in a living body (for example, an epidural space in which the distance between the spinal dura mater and the spinal column dorsal side is about 5 mm) when stimulating nerves of the spinal cord. Therefore, it is preferable that the diameter from the front-end | tip part 114 to the base end part 119 is about 1 mm-3 mm in the electrical stimulation apparatus 101.

  The electrical stimulation apparatus 101 is roughly composed of an electrode block 102, a circuit block 103, a support body 104, and a fixture 121. The electrode block 102 and the circuit block 103 can be attached / detached by a connector portion 107, and the circuit block 103 and the support body 104 can be attached / detached by a connector portion 109. Furthermore, the support body 104 and the fixture 121 are detachable, and are connected by a conductive wire 212 formed in a spiral shape. In this example, the body to which the electrode block 102, the circuit block 103, and the support 104 are connected is referred to as a main body block 122.

  More specifically, as shown in FIG. 2, in the electrode block 102 and the circuit block 103, the connector part 112 on the electrode block 102 side and the connector part 107 on the circuit block 103 side are fixed by screws or the like, for example. . Similarly, in the circuit block 103 and the support body 104, a connector portion 109 on the circuit block 103 side and a connector portion 113 on the support body 104 side are similarly fixed by screws or the like. And the fixing tool 121 is fixed to the base end part 119 of the support body 104 so that attachment or detachment is possible.

  Holes for inserting the stylet 120 are formed in the electrode block 102, the circuit block 103, the support body 104, and the fixture 121. These holes communicate in the axial direction in a state where four members such as the electrode block 102 are connected to form a stylet lumen. This stylet lumen is open to the proximal end portion 124 and is provided up to the vicinity of the distal end portion 114. The diameter of the stylet lumen is preferably substantially the same as or slightly longer than the diameter of the stylet 120.

  The electrode block 102 has a tip end portion 114 formed in a substantially hemispherical shape, and other portions formed in a substantially cylindrical shape. The radius of the substantially hemispherical portion of the tip 114 is preferably about 0.5 mm to 1.5 mm, and the diameter of the other substantially cylindrical portion is preferably about 1 mm to 3 mm. Such an electrode block 102 includes four stimulation electrodes 105 for stimulating nerves and the like so that each stimulation electrode 105 is exposed to the living body when the electrical stimulation device 101 is placed in the living body. It includes bodies 106 that are spaced apart. Further, a connector portion 112 is provided to connect the base end portion 115 side of the body 106 and the tip end portion 116 of the circuit block 103 so as to be continuous. In the example of the embodiment, the number of stimulation electrodes 105 is four. However, this is only an example, and the number of stimulation electrodes 105 can be arbitrarily set. The internal configuration of the electrode block 102 will be described later with reference to FIGS.

  The circuit block 103 is formed in a substantially cylindrical shape having the same diameter as the electrode block 102. The circuit block 103 includes a connector portion 107 that is connected to the connector portion 112 of the electrode block 102 so that the distal end portion 116 is continuous with the body 106 on the proximal end portion 115 side of the electrode block 102. The circuit block 103 is provided with a body 108 that is continuous with the connector portion 107. Further, a connector portion 109 that is continuous with the base end portion 117 of the body 108 and connects the base end portion 117 and the support body 104 is provided. The internal configuration of the circuit block 103 will be described later with reference to FIGS.

  The support body 104 is formed including a connector portion 113 connected to the circuit block 103, a body 110 formed in a substantially cylindrical shape having the same diameter as the electrode block 102, and a conductive wire 212 accommodated in the body 110.

  The connector part 113 of the support body 104 is connected to the connector part 109 of the circuit block 103 so that the front end 118 side of the body 110 is continuous with the circuit block 103. The body 110 can be cut so that the electrical stimulation device 101 can be completely implanted in the living body, and can be connected to the distal end 123 of the fixture 121 on the cut end, that is, the base end 119 side of the body 110. ing. The internal configuration of the support 104 will be described later with reference to FIGS.

  The fixture 121 is mainly made of a flexible material such as silicone or polyurethane, and the stylet 120 can be inserted into the stylet lumen that opens to the base end portion 124. The internal configuration of the fixture 121 will be described later with reference to FIG.

Next, an internal configuration of the electrical stimulation device according to the embodiment will be described with reference to FIGS.
FIG. 3 is an enlarged view showing a main body block and an axial internal structure thereof according to an embodiment of the present invention.
Fig.3 (a) is the expansion external view which looked at the main body block shown in FIG. 1 from the upper surface.
FIG. 3B is a cross-sectional view showing an AA ′ cross section of the main body block shown in FIG.

FIG. 4 is a cross-sectional view showing the internal structure of a predetermined portion in the direction perpendicular to the axis of the main body block according to one embodiment of the present invention.
Fig.4 (a) is sectional drawing which shows the BB 'cross section of the electrical stimulation apparatus shown to Fig.3 (a).
FIG.4 (b) is sectional drawing which shows CC 'cross section of the electrical stimulation apparatus shown to Fig.3 (a).
FIG.4 (c) is sectional drawing which shows DD 'cross section of the electrical stimulation apparatus shown to Fig.3 (a).
FIG.4 (d) is sectional drawing which shows the EE 'cross section of the electrical stimulation apparatus shown to Fig.3 (a).
FIG.4 (e) is sectional drawing which shows the FF 'cross section of the electrical stimulation apparatus shown to Fig.3 (a).
FIG.4 (f) is sectional drawing which shows the GG 'cross section of the electrical stimulation apparatus shown to Fig.3 (a).

First, the internal configuration of the electrode block 102 will be described.
The pipe 206 has biocompatibility, insulation, and a flexible material such as polytetrafluoroethylene (Poly Tetra Fluoro Ethylene: PTFE) or ethylene-tetrafluoroethylene copolymer (Ethylene-Tetra Fluoro Ethylene copolymer). : ETFE) and is formed in a hollow, substantially cylindrical shape. The outer diameter is about 0.1 mm to 1 mm, and the inner diameter is preferably approximately equal to or slightly longer than the diameter of the stylet 120 so that the stylet 120 can pass through the pipe 206. One end of the pipe 206 (the end on the distal end portion 114 side) is coupled to the receiving portion 213.

  The receiving part 213 is made of stainless steel and is formed in a substantially cylindrical shape, and has a substantially cylindrical hole at the center in the axial direction. The total length and diameter of the hole in the axial direction are shorter than the total length and outer diameter of the receiving portion 213 in the axial direction. Further, the diameter of the hole of the receiving portion 213 is preferably substantially equal to the outer diameter of the pipe 206 in order to fix the pipe 206 so as not to move in the axial direction or in a direction perpendicular to the axis. The pipe 206 and the receiving portion 213 are housed and fixed in an outer layer portion including the body 106, the stimulation electrode 105, and the connector portion 112.

  The body 106 is made of a flexible and biocompatible material, for example, a resin material such as silicone or polyurethane. As described above, the front end portion 114 of the body 106 is substantially hemispherical, and the radius thereof is preferably in the range of about 0.5 mm to 1.5 mm. And parts other than the front-end | tip part 114 of the body 106 are formed in the hollow substantially cylindrical shape.

  The inner diameter of the body 106 is different between a portion that contacts the receiving portion 213 and a portion that contacts the pipe 206. The inner diameter of the portion that contacts the receiving portion 213 is substantially equal to the outer diameter of the receiving portion 213 in order to fix the receiving portion 213. Further, the inner diameter of the portion that contacts the pipe 206 is substantially equal to the outer diameter of the pipe 206 in order to fix the pipe 206. As described above, the four stimulation electrodes 105 are fixed to the surface of the body 106 so as to be exposed to the hollow portion of the body 106 that is formed in a substantially cylindrical shape.

  The stimulation electrode 105 is made of a conductive and biocompatible material, such as platinum or a platinum alloy (platinum 90% / iridium 10% alloy, etc.), and is formed in a hollow, substantially cylindrical shape. Yes. The outer diameter of the stimulation electrode 105 is formed approximately equal to the outer diameter of the body 106. Moreover, it is desirable that the inner diameter of the stimulation electrode 105 is such a length that the stimulation electrode 105 and the pipe 206 provided therein do not contact. The four stimulation electrodes 105 are defined as stimulation electrodes 105a, 105b, 105c, and 105d in order from the one on the distal end portion 114 side.

  One end (end on the tip end 114 side) of the conducting wires 202a to 202d is bonded to the stimulation electrodes 105a to 105d by solder 203 (see FIG. 4A), and the other end (base) of the conducting wires 202a to 202d is attached. The end 115 side end) is electrically connected to the connector portion 112 (see FIG. 2A). It should be noted that the portions other than the portions of the conductive wires 202a to 202d that are bonded with the solder 203 and the portions that are electrically connected to the connector portion 112 are covered with insulation by PTFE or ETFE, so that the inside of the body 106 is completely covered. Embedded (see FIG. 4B).

  The connector portion 112 is formed of the same material as that of the body 106, and is formed as a notch portion provided with a step from the outer diameter of the body 106 having a substantially cylindrical shape. The notch is formed by a predetermined distance in the axial direction from the base end 115 (see FIG. 2A). The notch has a quadrangular shape, and four connector pins 210 (see FIG. 2A) are exposed on the notch. The conductors 202a to 202d are connected to the four connector pins 210. Are electrically connected.

Next, the internal configuration of the circuit block 103 will be described.
The pipe 207 arranged in the circuit block 103 is the same as the pipe 206 except for the length. The pipe 207 is housed and fixed in the outer layer portion including the connector portion 107, the body 108 continuous with the connector portion 107, and the connector portion 109 continuous with the body 108 (see FIG. 2B and FIG. 3B). ).

  The connector part 107 is made of the same material (polyurethane or silicone) as the body 106 except for the electrical connection part 211 described later. A hole having substantially the same shape as the outer diameter of the connector portion 112 is formed in the connector portion 107 in the axial direction so as to be connectable to the connector portion 112 of the electrode block 102 (see FIG. 4C). ). The outer diameter of the connector portion 107 is substantially equal to the outer diameter of the body 106. In addition, the connector part 107 includes an electrical connection part 211 that is electrically connected independently to the four connector pins 210 when connected to the connector part 112 of the electrode block 102.

  The body 108 of the circuit block 103 is continuous with the connector portions 107 and 109 and is made of the same material as the connector portions 107 and 109. The body 108 is formed in a hollow, substantially cylindrical shape, and its outer diameter is substantially equal to the outer diameter of the connector part 107 of the circuit block 103 coupled to the connector part 112, and the inner diameter is the same as the outer diameter of the pipe 207. It is formed almost equally.

  In the body 108, a stimulation circuit 205 that generates an electrical stimulation signal and in which a small component such as a custom IC is mounted on a flexible circuit board is embedded (see FIG. 4D).

  The stimulation circuit 205 is connected to the electrical connection portion 211 via the conductive wire 204 embedded in the body 108 so as to supply the generated electrical stimulation signal to each stimulation electrode 105 independently. Further, in order to obtain electric power for generating an electrical stimulation signal, the connector portion 109 is electrically connected. The electrical configuration of the stimulation circuit 205 will be described later with reference to FIG.

  The connector part 109 is the same as the connector part 107 except for the electrical connection part 215. The electrical connection unit 215 is electrically connected to the stimulation circuit 205 via a conductive wire (not shown) embedded in the body 108 in order to supply power obtained by the power receiving coil unit 219 described later to the stimulation circuit 205. .

Next, the internal configuration of the support 104 will be described.
The pipes 208 and 209 arranged in the support 104 are the same as the pipes 206 and 207 except for their lengths. A valve body 214 is provided between the pipe 208 and the pipe 209 in the axial direction.

  The valve body 214 is made of a biocompatible elastic material (particularly, a soft material is preferable) such as silicone rubber. The valve body 214 is opened at one end face on the pipe 208 side and intersects the first notch on the other end face and the first cut on the pipe 209 side. It has an opening and a second notch that does not open at the other end face. By providing this valve body 214, even when the stylet 120 is inserted and removed through the valve body 214, it is possible to prevent liquid such as body fluid from entering the electrode block 102 and the circuit block 103 from the pipe 209. it can.

  The pipes 208 and 209 and the valve body 214 are housed and fixed in the connector portion 113 and the body 110 continuous with the connector portion 113.

  The connector portion 113 is made of, for example, polyurethane or silicone, and has the same shape as the connector portion 112 (see FIG. 2A) of the electrode block 102 described above. Then, two connector pins 216 (see FIG. 2C and FIG. 3B) are exposed and arranged on the notch portion of the connector portion 113. The two connector pins 216 are connected to the connector portion 113 and a conductor 212 embedded in the body 110 (see FIGS. 4E and 4F). The conducting wire 212 is embedded in the body 110 so as not to penetrate the valve body 241.

  The body 110 is made of the same material as that of the connector portion 113 and is formed in a hollow cylindrical shape. The outer diameter of the body 110 is substantially equal to the outer diameter of the body 108 of the circuit block 103. In addition, the inner diameter of the body 110 is partly equal to the outer diameter of the pipe 209 on the tip 118 side, and the other part is longer than the outer diameter of the pipe 209. The conductor 110 is also embedded in the body 110 as described above.

  The conducting wire 212 includes two core wires 212a and 212b, and is covered with PTFE or ETFE so that the core wires 212a and 212b are electrically independent from each other. A part of the conducting wire 212 is formed in a spiral shape so that it can expand and contract in the axial direction of the main body block 122, and is housed in a portion where the inner diameter of the body 110 is longer than the outer diameter of the pipe 209. Core wires 212a and 212b are respectively connected to two connector pins 216 at one end of the conducting wire 212 (at the front end portion 118 side of the support 104), and the other end of the conducting wire 212 (at the base end portion 119 side of the support 104). ) Is connected to the fixture 121.

Next, the configuration of the fixture 121 will be described with reference to FIG.
FIG. 5 is an enlarged view showing the fixture according to one embodiment of the present invention and the internal structure in the axial direction thereof.
Fig.5 (a) is the expansion external view which looked at the fixing tool shown in FIG. 1 from the upper surface.
FIG. 5B is a cross-sectional view showing the HH ′ cross section of the fixture shown in FIG.
FIG.5 (c) is an enlarged view of the upper surface which looked at the fixing tool shown to Fig.5 (a) from the base end part side.
FIG.5 (d) is an enlarged view of the bottom face which looked at the fixing tool shown to Fig.5 (a) from the front-end | tip part side.

  The fixture 121 is formed of silicone or the like, and includes a cap portion 217 and an opening 218 continuous with the cap portion 217.

  The cap part 217 is formed in a hollow substantially cylindrical shape. The diameter of a part of the hollow portion is approximately equal to or slightly longer than the outer diameter of the body 110 of the support 104 so that a part of the support 104 on the base end 119 side of the body 110 can be accommodated. It is preferable that It is desirable that the diameter of the other hollow portion is approximately equal to or slightly longer than the diameter of the stylet 120 so that the stylet 120 can pass through.

  Moreover, as shown in FIG.5 (b), the receiving coil part 219 is embedded in the cap part 217. FIG. The power receiving coil portion 219 is a circuit including a coil formed by winding the core wires 212 a and 212 b of the conducting wire 212 connected to the bottom surface of the cap portion 217 into a cylindrical shape.

  The opening 218 is formed in a substantially cylindrical shape having a hollow communicating with the hollow portion of the cap portion 217. It is desirable that the inner diameter of the opening 218 is approximately equal to or slightly longer than the diameter of the stylet 120 in order to insert the stylet 120. Moreover, although the outer diameter of the opening part 218 is shorter than the outer diameter of the cap part 217 in FIG. 5, it is not limited to this.

  As described above, the stylet lumen is formed by the receiving portion 213, the pipes 206 to 209, the valve body 214, and the fixture 121.

[2. Configuration of stimulation circuit]
Next, a more detailed electrical configuration of the stimulation circuit 205 of the circuit block 103 and the power receiving coil portion 219 of the fixture 121 will be described with reference to FIG.
FIG. 6 is a block diagram illustrating functions of the stimulation circuit and the power receiving coil unit according to the embodiment of the present invention.

  The stimulation circuit 205 includes a communication unit 302, a stimulation parameter setting unit 304, an electrode configuration setting unit 305, an oscillation unit 306, and a control unit 303. Furthermore, a charging unit 308, a rechargeable battery 309, and a switch unit 307 are provided.

  The rechargeable battery 309 is a rechargeable battery such as a lithium ion battery. The rechargeable battery 309 supplies the accumulated power to each block constituting the stimulation circuit 205.

  The power receiving coil unit 219 is a resonance circuit including, for example, a coil and a capacitor. When charging the rechargeable battery 309, the power receiving coil unit 219 receives an electromagnetic wave for charging transmitted from an external controller (not shown). Accompanying reception by the power receiving coil unit 219, an alternating current generated from the power receiving coil unit 219 is output to the charging unit 308. The power receiving coil unit 219 receives an electromagnetic wave on which predetermined information is transmitted, which is transmitted from an external controller (not shown), and outputs the received electromagnetic wave to the communication unit 302.

  The charging unit 308 includes a rectifier circuit, converts the alternating current output from the power receiving coil unit 219 into a direct current, and acquires power. Then, the rechargeable battery 309 is charged with the acquired power.

  The communication unit 302 demodulates the electromagnetic wave received by the power receiving coil unit 219 and extracts information placed on the electromagnetic wave. Then, the extracted information is output to the stimulation parameter setting unit 304 and the electrode configuration setting unit 305 via the control unit 303. Information output to the stimulation parameter setting unit 304 is information related to the stimulation intensity of the electrical stimulation signal (hereinafter referred to as “stimulation parameter”), and information output to the electrode configuration setting unit 305 is information related to the electrode configuration ( Hereinafter, this is referred to as “electrode configuration information”. Since the stimulation intensity of the electrical stimulation signal is determined by the pulse voltage, pulse current, pulse width, or frequency of the electrical stimulation signal, the stimulation parameter is a signal indicating values such as the pulse voltage. The electrode configuration information is a signal including information for changing the polarity of the electrical stimulation signal and information for causing the switch unit 307 to select the stimulation electrode 105 that outputs the electrical stimulation signal.

The stimulation parameter setting unit 304 generates a stimulation intensity change signal for changing the stimulation intensity of the electrical stimulation signal generated by the oscillation unit 306 based on the stimulation parameter input from the communication unit 302.
The electrode configuration setting unit 305 generates an electrode configuration selection signal for selecting the stimulation electrode 105 that outputs the electrical stimulation signal generated by the oscillation unit 306 based on the electrode configuration information input from the communication unit 302. The stimulus intensity change signal is output to the oscillation unit 306. On the other hand, the electrode configuration selection signal is output to the switch unit 307.

The oscillation unit 306 generates an electrical stimulation signal based on the stimulation intensity change signal input from the stimulation parameter setting unit 304 and outputs the electrical stimulation signal to the switch unit 307.
The switch unit 307 selects the stimulation electrode 105 that outputs the electrical stimulation signal input from the oscillation unit 306 based on the electrode configuration selection signal input from the electrode configuration setting unit 305. The control unit 303 is a microcomputer, for example, and controls each block of the stimulation circuit 205.

[3. Procedure for implanting electrical stimulator]
Next, an example of a procedure for implanting the electrical stimulation device 101 into, for example, the epidural space and performing electrical stimulation of spinal nerves with the electrical stimulation device 101 will be described with reference to FIGS.
7 to 12 are cross-sectional views of the human body showing the vicinity of the back.

  First, the doctor determines a target spinal stimulation site in advance based on the distribution of pain of the patient. Then, puncture is performed from the back side of the patient under fluoroscopy, and the epidural needle 402 is inserted into the epidural space 405. Generally, the position where the epidural needle 402 is inserted into the epidural space 405 is selected to be three or more vertebral bodies or lower from the target stimulation site (see FIG. 7). In this example, the epidural needle 402 is used to insert the electrical stimulation device 101 into the living body, but is not limited thereto. For example, a tubular introducer such as a cannula can be used.

  Next, the doctor inserts the stylet 120 into the stylet lumen of the electrical stimulation apparatus 101 and places the tip of the stylet 120 on the receiving portion 213. Then, the distal end portion 114 (see FIG. 1) of the electrical stimulation device 101 is passed through the epidural needle 402, and the electrical stimulation device 101 is inserted into the living body 404. Then, by pushing the proximal end of the stylet 120 in the axial direction, the electrical stimulation device 101 is inserted into the epidural space 405 (see FIG. 8, the stylet 120 is not shown).

  Subsequently, the doctor further pushes the proximal end of the stylet 120 in the axial direction to raise the electrical stimulation device 101 into the epidural space 405 and target the stimulation electrode 105 of the electrical stimulation device 101. Located near. Then, while moving the position of the stimulation electrode 105 little by little, the nerve stimulation is performed by operating the electrical stimulation apparatus 101 with a controller (not shown), and the pain relieving effect is maximized while listening to the patient's response to the nerve stimulation. The optimum position of the stimulation electrode 105 is determined.

  Subsequently, the doctor performs a process for completely implanting the electrical stimulation apparatus 101 into the living body 404. Specifically, first, a small incision is made in a portion where the epidural needle 402 is inserted. Then, the stylet 120 is removed from the stylet lumen of the electrical stimulation device 101, and the epidural needle 402 is removed from the living body 404 (see FIG. 9). However, when the outer diameter of the cap portion 217 (see FIG. 5) of the fixture 121 is larger than the inner diameter of the epidural needle 404, a slit is formed from the distal end to the proximal end instead of the epidural needle 404. Type of epidural needle (hereinafter referred to as “slit epidural needle”). In this case, the doctor pulls the slit epidural needle while applying a force in the vertical direction of the slit. Then, the slit portion of the epidural needle is opened, and only the epidural needle is removed from the living body 404 as shown in FIG.

  Here, the doctor pulls the fixture 121 in the axial direction of the electrical stimulation device 101 while fixing the main body block 122 by hand, and releases the connection between the fixture 121 and the support 104 (see FIG. 10). And the broken-line part (part of body 110 of the support body 104 which protruded outside the body) of the support body 104 shown in FIG. 10 is cut | disconnected so that the conducting wire 212 may not be cut.

  Subsequently, the doctor pushes the fixture 121 in the axial direction of the electrical stimulation device 101 while fixing the main body block 122 by hand (see FIG. 11), and stores the lead 212 inside the body 110 of the support 104. . Then, the cutting surface of the support 104 is capped with a fixing tool 121, a thread is passed through the fixing tool 121, and the fixing tool 121 is fixed to the body 110 by binding with the thread (see FIG. 12).

  Then, in order to fix the electrical stimulation apparatus 101 to the living body 404 in a state where it is completely implanted in the living body 404, the fixing device 121 is connected to a fascia or a small incision in the living body 404 with a thread (not shown). Sew to tissue. This treatment is for preventing the electrical stimulation device 101 from moving in the living body 404 or preventing an infection from being caused from the insertion opening of the electrical stimulation device 101. Moreover, it is also for making the coil surface of the receiving coil part 219 of the fixing tool 121 of the electrical stimulator 101 parallel to the skin. Then, the small incision is sutured and the electrical stimulation device 101 is completely implanted in the living body 404.

  Next, the doctor places the controller (not shown) on the body surface so that the coil surface of the controller (not shown) outside the body overlaps the coil surface of the power receiving coil unit 219. Then, a nerve stimulation is performed by operating a controller (not shown). At this time, in the stimulation circuit 205 of the electrical stimulation apparatus 101, an electrical stimulation signal having a predetermined intensity is generated based on the operation of the doctor, and the generated electrical stimulation signal is output to the stimulation electrode 105, so that the stimulation electrode Neural stimulation in a portion near the position 105 is performed. In addition, charging of the rechargeable battery 309 of the electrical stimulation apparatus 101 is also performed by operating this controller (not shown).

  As described above, in one embodiment, when the electrical stimulation device is completely implanted in the body, the fixing tool is fixed to the proximal end portion of the body of the support body, and the coil of the power receiving coil portion provided in the fixing portion The surface can be substantially parallel to the body surface. That is, it is possible to easily align the axis with the coil of the controller that is placed outside the body and performs charging, parameter setting, and the like for the electrical stimulation device. Thereby, efficient power feeding and communication can be easily performed. As a result, there is an effect that the controller (external device) that oscillates electromagnetic waves with respect to the power receiving coil can be reduced in size.

  Moreover, in one Embodiment, the receiving coil part is arrange | positioned at the base end part side of the cut | disconnected support body. Therefore, when the electrical stimulation device is completely implanted in the living body, the power receiving coil portion can be implanted near the skin. Thereby, the intensity | strength of electromagnetic waves required in order for a receiving coil to generate electric power by electromagnetic induction can be reduced. As a result, there is an effect that the controller (external device) that oscillates electromagnetic waves with respect to the power receiving coil can be further downsized.

  In one embodiment, the stylet can be used when the electrical stimulation apparatus is implanted in the living body by providing the stylet lumen communicating with the electrode block, the circuit block, the support, and the fixture. Therefore, the electrical stimulation device can be easily implanted into the body, and the accuracy of placement of the stimulation electrode in the living body can be further improved.

<Modification>
In the above-described embodiment, the electrical stimulation device is directly passed through the epidural needle when the electrical stimulation device is inserted into the living body. However, after guiding the flexible cannula through the epidural needle to the vicinity of the site to be stimulated, the stimulating electrode can be accurately placed in the living body by inserting the cannula into the living body through the electric stimulator. It is possible to improve the property.

  Moreover, in one Embodiment mentioned above, the electrode block, the circuit block, and the support body were each connected so that attachment or detachment was possible with the connector. However, the connector may be eliminated and the electrode block and the circuit block may be integrated in advance, or the circuit block and the support may be integrated in advance, or all may be integrated in advance. Good.

  Moreover, in one Embodiment mentioned above, although the fixing tool and the conducting wire were integrated previously, it is good also as the conducting wire of a fixing tool and a main body block being detachable with a connector. When implanting such an electrical stimulation device in a living body, a doctor implants the electrical stimulation device in a predetermined position in the living body according to the procedure shown in FIGS. Then, after removing the fixture from the electrical stimulation device, the epidural needle is removed from the living body. Needless to say, only the main body block may be implanted in the living body first, the epidural needle may be removed from the living body, and then the lead wire of the main body block and the fixture may be connected by a connector.

  In the above-described embodiment, a rechargeable battery is used as a power source. However, a capacitor may be used instead of the rechargeable battery, and the battery may be operated while being always supplied with power from an external controller.

  In the above-described embodiment, the fixing tool, the support body, the circuit block, and the electrode block are formed with stylet lumens that communicate in the axial direction. However, the stylet lumen may be formed so as to communicate only with the fixture, the support, and the circuit block, or may be formed on the fixed portion and the support. Further, a lumen (guide wire lumen) communicating from the proximal end portion of the fixture to the distal end portion of the electrode block may be formed. If the guide wire lumen is provided, the electrical stimulation device can be implanted into the body using the guide wire. Of course, the configuration may be such that the stylet lumen and the guide wire lumen are not provided.

  Moreover, in one Embodiment mentioned above, although the electrical stimulation apparatus 101 is formed in the substantially cylindrical shape, what kind of shape may be sufficient if it is a rod-shape.

  As mentioned above, although the example of each embodiment of the present invention was explained, the present invention is not limited to the above-mentioned each embodiment, and it is not limited to the scope of the present invention described in the claims. Needless to say, modifications and application examples are included.

  DESCRIPTION OF SYMBOLS 101 ... Electrical stimulation apparatus, 102 ... Electrode block, 103 ... Circuit block, 104 ... Support body, 105 ... Stimulation electrode, 106, 108, 110 ... Body, 107, 109, 112, 113 ... Connector part, 114, 116, 118 , 123 ... distal end portion, 115, 117, 119, 124 ... proximal end portion, 120 ... stylet, 121 ... fixture, 202, 204, 212 ... conductor, 203 ... solder, 205 ... stimulation circuit, 206 to 209 ... pipe , 210, 216 ... connector pins, 211, 215 ... electrical connection part, 213 ... receiving part, 214 ... valve body, 217 ... cap part, 218 ... opening part, 219 ... receiving coil part, 302 ... communication part, 303 ... Control unit 304 ... Stimulus parameter setting unit 305 ... Electrode configuration setting unit 306 ... Oscillation unit 307 ... Switch unit 308 ... Charging unit 309 ... battery, 402 ... epidural needle, 403 ... spine, 404 ... biological, 405 ... epidural space

Claims (6)

An electrical stimulation device that is formed into a deformable rod shape and is implanted in a living body,
A stimulation circuit block having a stimulation electrode for stimulating nerves or muscles in the living body and an electronic circuit electrically connected to the stimulation electrode and applying a stimulation signal to the stimulation electrode; and connected to the stimulation circuit block A body block including a support for holding the implantation position of the stimulation electrode in the living body;
Including a coil portion that feeds and / or communicates with the electronic circuit in response to electromagnetic waves oscillated from an external device, and includes a fixture provided at a base end portion of the body block,
The electrical stimulation device, wherein the electronic circuit and the coil portion are connected by a conducting wire, and at least a part of the conducting wire is formed in a spiral shape so as to be expandable and contractible. The support is at least partially hollow;
The electrical stimulation device according to claim 1, wherein the spirally formed conducting wire is housed in the hollow portion of the support. The electrical stimulation device according to claim 1, wherein a lumen communicating with the hollow portion of the support is formed on the fixture and / or the main body block. The electrical stimulation device according to claim 3, wherein the lumen is formed up to a vicinity of a distal end portion of the stimulation circuit block, and a stylet can be inserted. The electrical stimulator according to any one of claims 1 to 4, wherein the support is severable. The electrical stimulation device according to claim 5, wherein the fixture is connectable to the support so as to cover a cut surface of the support.

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