JP2012228359A - Electrostimulation electrode assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostimulation electrode assembly even if an external force acts on a site located outside a body, the electrostimulation is difficult to be transmitted to an indwelling electrode in blood vessel.SOLUTION: An electrostimulation electrode assembly 1 indwells in blood vessel, and comprises an insulating body 10 having a tubular first sheath 11 and a tubular second sheath 12 inserted in the first sheath, an electrode part 20 having electrodes with exposed surfaces which is mounted on a tip side of the body, and a bias part 30 having biasing members 31, 32 of elastic bodies for biasing the electrode part toward the wall surface of blood vessel, and it is characterized in that the first and second sheaths can move relatively in the longitudinal direction and rotate relatively around the axis line.

Description

  The present invention relates to an electrical stimulation electrode assembly placed in a body.

2. Description of the Related Art Conventionally, stimulation generators that perform treatment by applying electrical stimulation to living tissue are known. Examples of such a stimulus generator include a cardiac pacemaker, an implantable defibrillator, a nerve stimulator, a pain relieving device, an epilepsy treatment device, and a muscle stimulator.
Usually, these stimulation generators include an electrode lead (electric stimulation electrode assembly) disposed in the vicinity of a tissue to be stimulated in a living body.

  As such an electrode lead, for example, a living body provided with an electrode support having at least one arm portion on which an electrode is formed, and this arm portion is wound around a living tissue such as a cervical vagus nerve An implantable electrode lead is described.

  It has also been proposed to place an electrode lead in a blood vessel located adjacent to the nerve to be stimulated to provide electrical stimulation across the vessel wall in order to avoid nerve stimulation due to contact with the nerve. Yes. Patent Document 1 describes an electrode lead used for such an application. The electrode lead has a helical structure in the distal region that is placed in the blood vessel and is supported in the blood vessel by contacting the helical structure with the vessel wall.

Special table 2010-516385 gazette

  However, in the electrode lead described in Patent Document 1, when an external force is applied to the end exposed outside the body due to the patient's body movement or the like when connecting the end exposed outside the body and the stimulation generator, the external force is applied. Directly transmitted to the distal region. As a result, there is a problem that the electrode support may be moved in the axial direction to deviate from the indwelling position, or may deform and inhibit blood flow, thereby inducing the formation of a thrombus.

  The present invention has been made in view of the above-described circumstances, and provides an electrical stimulation electrode assembly that is difficult to be transmitted to an electrode placed in a blood vessel even when an external force acts on a portion located outside the body. The purpose is to do.

  The present invention relates to an electrical stimulation electrode assembly that is placed in a blood vessel, and includes an insulating main body having a tubular first sheath and a tubular second sheath inserted into the first sheath, and an electrode A biasing member having an electrode with an exposed surface, an electrode part provided on the distal end side of the main body part, and a biasing member made of an elastic body, biasing the electrode part toward the wall surface of the blood vessel The first sheath and the second sheath are relatively movable in the longitudinal direction and relatively rotatable about the axis.

  The electrical stimulation electrode assembly according to the present invention may further include a separation portion that is provided in an intermediate portion in the longitudinal direction of the first sheath and separates the first sheath into a distal end region and a proximal end region. .

  The electrical stimulation electrode assembly according to the present invention further includes a connector provided on the first sheath and connected to the stimulation generator, and a wiring that electrically connects the electrode and the connector. May have a surplus portion that is wound to form a plurality of loops.

  The electrical stimulation electrode assembly according to the present invention is an inner cavity of the first sheath, and is disposed between the inner surface of the first sheath and the outer surface of the second sheath, and allows blood to enter the main body. You may further provide the seal | sticker which suppresses permeation.

  Furthermore, the electrical stimulation electrode assembly of the present invention further includes a second seal that is a lumen of the first sheath and is provided on a proximal end side with respect to the seal, and suppresses blood intrusion into the connector. You may prepare.

  According to the electrical stimulation electrode assembly of the present invention, even if an external force is applied to a part located outside the body, it is difficult to transmit to the electrode placed in the blood vessel. Can be suppressed.

It is a figure which shows typically the electric stimulation electrode assembly of 1st embodiment of this invention. It is a figure which shows one form at the time of use of the same electrical stimulation electrode assembly. It is a schematic diagram which shows the state by which the same electrical stimulation electrode assembly was detained in the blood vessel. It is a figure which shows the operation | movement at the time of extraction of the electrical stimulation electrode assembly. It is a figure which shows typically the electrical stimulation electrode assembly of 2nd embodiment of this invention. It is a perspective view which shows the electrode part and urging | biasing part in the modification of the electrical stimulation electrode assembly of this invention. It is a perspective view which shows the electrode part and urging | biasing part in the modification of the electrical stimulation electrode assembly of this invention. It is a figure which shows an example of the connector structure corresponding to the electrode part. It is a perspective view which shows the electrode part and urging | biasing part in the modification of the electrical stimulation electrode assembly of this invention. It is a perspective view which shows the electrode part and urging | biasing part in the modification of the electrical stimulation electrode assembly of this invention. It is a figure which shows the state which looked at the same electrode part and the energizing part from the front end side of the 2nd sheath.

A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram schematically showing an electrical stimulation electrode assembly (hereinafter simply referred to as “electrode assembly”) 1 of the present embodiment. The electrode assembly 1 is placed in a blood vessel and applies electrical stimulation to a predetermined target tissue such as a vagus nerve through a blood vessel wall. The body 10 is formed in a tubular shape, and the distal end of the body 10 The electrode part 20 attached to the side and the urging | biasing part 30 for indwelling the electrode part 20 in the blood vessel are provided.

  The main body portion 10 includes a first sheath 11 formed in a tubular shape and a tubular second sheath 12 inserted on the distal end side of the first sheath 11, and is sufficiently small with respect to the inner diameter of the indwelling blood vessel. Has an outer diameter. The first sheath 11 and the second sheath 12 are formed of an insulating material having flexibility. As the insulating material, a material excellent in biocompatibility is preferable, and examples thereof include a silicone resin, a polyurethane resin, and a fluororesin. Examples of the fluororesin include tetrafluoroethylene / ethylene copolymer (ETFE) and polytetrafluoroethylene (PTFE). The surface of each sheath 11 and 12 may be provided with a thrombus prevention coating as necessary.

On the proximal end side of the first sheath 11, a connector 13 connected to a stimulus generator that generates electrical stimulation is provided. The connector 13 can adopt a known configuration as appropriate according to the device to be connected.
Examples of the stimulus generator connected to the electrode assembly 1 include those conventionally used in cardiac pacemakers, defibrillators, nerve stimulators, pain relief devices, epilepsy treatment devices, muscle stimulators, and the like. . Stimulation generators include those that are implanted in the living body and those that are worn outside the body. In any case, an electrode driving power source (battery), an electrical circuit for generating a stimulation signal for treatment, And a connection portion connected to the connector 13.
In addition, an easily cut portion (separation portion) 15 formed of a flexible resin or the like is provided in the middle portion in the longitudinal direction of the first sheath 11, and the first sheath 11 is removed by a user tearing it by hand. It can be separated into a distal end side region and a proximal end side region. The easy cutting portion 15 is used when the electrode assembly 1 is removed, and details thereof will be described later.

  The outer diameter of the second sheath 12 is formed to be smaller than the inner diameter of the first sheath 11, and is inserted into the first sheath 11 so as to be able to advance and retract in the longitudinal direction and to be relatively rotatable around its own axis. . An electrode portion 20 and a biasing portion 30 are attached to the distal end side of the second sheath 12. On the distal end side of the first sheath 11, a gap between the inner surface of the first sheath 11 and the outer surface of the second sheath 12 is sealed with a seal 14, and water tightness is maintained. The seal 14 is preferably highly biocompatible and has a slip property that does not hinder the relative rotation between the first sheath 11 and the second sheath 12. For example, the seal 14 is made of a material such as grease or gel, or an anti-resistant such as heparin. A hydrophilic polymer or hydrogel mixed with a drug having a thrombotic action can be used. Examples of hydrophilic polymers include 2-methacryloyloxyethyl phosphorylcholine (MPC), methyl vinyl ether maleic anhydride copolymer (VEMA), and examples of hydrogels include hyaluronic acid, carboxymethyl cellulose, polyvinyl pyrrolidone, poly Examples thereof include those containing hydroxyethyl methacrylate, polyethylene glycol, methyl vinyl ether maleic anhydride and the like.

  The electrode unit 20 includes two electrodes, a negative electrode 21 and a positive electrode 22, and each electrode 21, 22 exposes a conductive electrode surface. As the material for the electrode surface, a metal material excellent in biocompatibility is preferable, and examples thereof include noble metal materials such as platinum iridium alloys. Wirings 23 for supplying electrical energy to the electrodes 21 and 22 are connected to the connector 13 from the electrodes 21 and 22 through the lumens of the second sheath 12 and the first sheath 11.

  The urging unit 30 includes a pair of urging members 31 and 32 made of an elastic body. Each of the biasing members 31 and 32 is flexible so that it can be reversibly deformed into a first shape and a second shape, which will be described later, and can maintain a certain shape against deformation of the indwelling blood vessel wall. For example, it can be suitably formed using a superelastic wire made of nickel titanium or the like. If necessary, the surface of the urging member may be coated with a biocompatible resin, or a coating for preventing thrombus may be applied.

  The urging members 31 and 32 are in an arc shape having a predetermined radius of curvature when viewed in the axial direction of the main body portion 10 in a natural state where no external force is applied, and the electrode portion 20 at or near the midpoint position of the arc. Is positioned and the shape of the electrode surface is set so as to exhibit a state in which the electrode surface faces the outside of the arc (hereinafter, this state is defined as “first shape”). The predetermined radius of curvature in the first shape differs depending on the blood vessel diameter of the site (indwelling site) where the electrode assembly 1 is to be placed, and is set slightly larger than the radius of the indwelling site. Further, the length of the urging members 31 and 32 when viewed in the axial direction of the main body 11 is such that the portion of the inner wall of the blood vessel (hereinafter sometimes referred to as the vascular wall) that is in contact with the urging member is superior. It is preferable to set it to 1/2 or more of the circumference of the blood vessel wall at the indwelling site so as to form an arc.

The operation during placement of the electrode assembly 1 configured as described above will be described using an example in which the vagus nerve is placed in the superior vena cava as a stimulation target tissue.
First, the surgeon cuts the skin of the patient's neck and forms an incision in the superior vena cava. Next, the operator inserts a tubular member such as an introducer or a guide sheath into the incision, and positions the distal end of the tubular member in the vicinity of the inner wall of the blood vessel where the vagus nerve is parallel.

  Next, the surgeon pushes the second sheath 12 into the first sheath 11 while folding the urging portion 30 by hand, and the electrode portion 20 and the urging portion 30 are moved into the first sheath 11 as shown in FIG. To house. By this operation, the urging portion 30 is deformed into a second shape that fits in the lumen of the first sheath 11.

  Subsequently, the operator inserts the electrode assembly 1 into the tubular member, advances the inside of the blood vessel, and protrudes from the distal end opening of the tubular member into the superior vena cava. The surgeon confirms the distal end position of the first sheath 11 by means of an X-ray fluoroscopic image or the like, and when the distal end comes before the placement position of the electrode portion 20, the rod-like placement accessory 2 is connected to the connector 13 as shown in FIG. Insert from a hole (not shown) provided at the base end. Then, the proximal end of the second sheath 12 is pushed with the distal end of the indwelling accessory 2 to advance the second sheath 12 relative to the first sheath 11. Then, the electrode part 20 and the urging | biasing part 30 come out of the 1st sheath 11, and the urging members 31 and 32 return to the 1st shape along a blood vessel wall, and contact a blood vessel wall. The urging members 31 and 32 may be slightly elastically deformed because they are pushed by the blood vessel wall that has come into contact with each other, but at least keep the state along the inner wall of the blood vessel due to their rigidity. As a result, the urging unit 30 urges the main body 10 so that the electrode surface of each electrode of the electrode unit 20 comes into close contact with the blood vessel wall in contact with the blood vessel wall, and during the placement of the electrode assembly 1, Good contact with the vessel wall is maintained.

  FIG. 3 schematically shows the electrode assembly 1 after completion of placement in the blood vessel V. Of the main body 10, the proximal end side of the first sheath 11 and the easily cut portion 15 are exposed from the proximal end of the tubular member 100 to the outside of the body. Since the electrode part 20, the urging part 30, and the distal end side (mainly the second sheath 12) of the main body part 10 are all installed along the inner wall of the blood vessel V, the blood flow in the blood vessel V is inhibited. Hateful. Therefore, the electrode assembly 1 can be placed while suppressing the generation of thrombus due to the placement of the electrode assembly 1.

  After the electrode assembly 1 is placed, the connector 13 is connected to the stimulus generator, and a preset electrical stimulus pulse is applied from the stimulus generator. Thereby, the electrical stimulation energy released from the electrode part 20 is transmitted to the vagus nerve through the blood vessel wall, and is indirectly electrically stimulated for treatment.

  If the patient unintentionally touches the first sheath 11 exposed outside the body during the placement of the electrode assembly 1 or the positional relationship between the electrode assembly 1 and the stimulus generator changes due to body movement or the like, the main body 10 External force may act on the. Such an external force may cause the electrode unit 20 to move from the indwelling position and cause a positional shift. However, the main body 10 of the electrode assembly 1 includes a first sheath 11 and a second sheath 12, and these Since the sheaths 11 and 12 are relatively movable in the longitudinal direction and relatively rotatable about the axis, the applied external force is absorbed by the relative movement of the first sheath 11 and the second sheath 12, and almost the second sheath. 12 is not transmitted. Therefore, the positional deviation of the electrode part 20 is suitably prevented, and the electrode unit 20 is stably placed at a predetermined placement position.

  When the electrode assembly 1 is removed due to the end of the treatment or the like, the operator tears the easy-cutting portion 15 of the first sheath 11 and, as shown in FIG. 4, the first sheath 11 and the proximal end region 11A. It separates into two with the tip side region 11B. Then, the proximal end portion of the second sheath 12 exposed from the proximal end of the distal end side region 11 </ b> B of the first sheath is gripped and retracted, and the electrode portion 20 and the urging portion 30 are accommodated in the first sheath 11. Thereafter, the distal end side region 11B is grasped, the electrode assembly 1 is removed from the blood vessel V, and the opening formed in the blood vessel is closed.

  As described above, according to the electrode assembly 1 of the present invention, an external force acting on a portion of the main body exposed to the outside of the body is difficult to be transmitted to the distal end side of the main body placed in the body. It is possible to perform treatment more safely by suitably preventing displacement of the electrode portion and the like.

  In addition, since the seal 15 is disposed in the gap between the first sheath 11 and the second sheath, it is possible to prevent blood and the like from entering the main body portion 10 through the gap during indwelling. As a result, it is possible to suitably suppress the occurrence of problems caused by the blood that has entered the main body coagulating.

  In the present embodiment, an example in which the separation unit is an easily cut portion has been described. However, the configuration of the separation unit is not limited to this, and is, for example, a flexible tube body that is detachably attached to the first sheath. May be. If the separation part is soft, when the seal 15 is highly slidable, the operator holds the first sheath and the second sheath while deforming the separation part and projecting it toward the lumen, so that the indwelling operation is performed. The relative movement between the first sheath and the second sheath inside can be prevented.

  Next, a second embodiment of the present invention will be described with reference to FIG. The difference between the electrode assembly 41 of the present embodiment and the electrode assembly 1 described above is the mode of the main body and wiring. In the following description, components that are the same as those already described are assigned the same reference numerals and redundant description is omitted.

  FIG. 5 is a diagram schematically showing the electrode assembly 41. The base end side of the wiring 42 connected to the connector 13 is an extra length portion 42A that is wound so as to form a plurality of loops. A second seal 43 that prevents liquid from entering the connector 13 is attached to the distal end side of the connector 13. The material of the second seal 43 is not particularly limited as long as the tip end side of the connector 13 can be sealed in a watertight manner with the wiring 42 passing therethrough, and for example, rubber packing or the like can be used.

Also in the electrode assembly 41 of this embodiment, similarly to the electrode assembly 1 of the first embodiment, it is possible to suitably prevent the displacement of the electrode portion due to an external force acting on the main body portion.
Further, since the extra length portion 42A is provided in the wiring 42, when the first sheath 11 and the second sheath 12 are relatively moved so as to be separated from each other, the extra length portion 42A extends to act on the wiring 42. Absorbs external forces. Therefore, it is possible to suitably prevent the occurrence of problems due to the wiring 42 being pulled or disconnected.
Further, since the second seal 43 is provided, even if a liquid such as blood enters the main body 10 beyond the seal 14, the liquid does not enter the connector 13, and a problem due to the liquid occurs. Can be prevented more reliably.

  The embodiments of the present invention have been described above. However, the technical scope of the present invention is not limited to the above-described embodiments, and the combinations of the components or the components may be changed without departing from the spirit of the present invention. It is possible to make various changes to or delete them.

  For example, in the electrode assembly of the present invention, the configurations of the electrode portion and the biasing portion are not limited to those described above, and can be variously changed. Below, some modifications of an electrode part and a biasing part are shown.

  In the modification shown in FIG. 6, the urging unit 50 is configured by three urging members 51, 52, and 53. Each biasing member protrudes radially while being shifted by 120 degrees around the axis when viewed in the axial direction of the second sheath 12. In the blood vessel, the urging members 51, 52, and 53 protrude radially to urge the negative electrode 21 and the positive electrode 22 to press against the blood vessel wall.

  In the modification shown in FIG. 7, the electrode portion has a multipolar configuration in which a plurality of positive electrodes and negative electrodes are provided. The urging unit 60 is configured such that two urging members 61 and 62 having an annular shape when viewed in the axial direction of the second sheath 12 are attached to the second sheath 12 with an interval in the axial direction of the second sheath 12. It is formed by. Five positive electrodes 22A to 22E are attached to the urging member 61 on the proximal end side, and five negative electrodes are attached to the urging member 62 on the distal end side in a circumferential position corresponding to each of the positive electrodes 22A to 22E. 21A to 21E are attached.

When the electrode part has a multipolar configuration, the connection mode of the wiring to the electrode part may be set as appropriate, and may be connected to all the positive or negative electrodes of one wiring, or the five positive electrodes may be wired independently. May be. When taking the latter mode, it is possible to finely adjust the manner of applying electrical stimulation by energizing any positive and negative electrodes.
FIG. 8 shows an example of the internal structure of the connector in the case of a multipolar configuration and independent wiring to each electrode. In the connector 90, terminals 91A to 91E corresponding to the negative electrodes 21A to 21E (not shown in FIG. 8) are arranged in the longitudinal direction, and positive electrodes 22A to 22E (not shown in FIG. 8). A region in which terminals 92A to 92E corresponding to each of the terminals 92A to 92E are aligned in the longitudinal direction is formed.
Here, a marker may be provided on a part or all of each terminal to improve the visibility of each terminal, or to make the correspondence with the electrodes easy to understand. There is no restriction | limiting in particular in the specific aspect of a marker, You may set freely, such as a color, a shape, a pattern, or those combination.

  The modification shown in FIG. 9 is an example in which the urging portion 70 is configured by a single urging member 71 having two loop portions 71A and 71B, with the same multipolar configuration as the modification of FIG. . In this case, when the urging portion 70 is accommodated in the first sheath, the urging portion 70 extends substantially in a straight line, so that the resistance at the time of insertion into and removal from the first sheath is reduced, and the electrode assembly can be easily handled.

  The urging portion 80 of the modification shown in FIGS. 10 and 11 is formed by bending two loop portions 81 having an annular shape when viewed in the axial direction of the second sheath 12 in a side view of the second sheath 12, respectively. This is formed by a biasing member 81 </ b> A, and the loop portions 81 are connected by a linear biasing member 82. This shape is a configuration close to a known self-expanding stent. In the first expanded shape, the electrodes 21 and 22 of the electrode portion are firmly urged toward the blood vessel wall in close contact with the blood vessel wall. It can be easily folded in the radial direction to be deformed into the second shape, and can be easily put in and out of the first sheath.

  Further, in each of the above-described embodiments, the example in which the distal end of the first sheath is positioned in the blood vessel at the time of indwelling has been described. Instead, the distal end of the first sheath is positioned outside the body at the time of indwelling. The dimensions of the first sheath and the second sheath may be set. In this case, since the possibility that blood or the like enters the lumen of the first sheath is considerably reduced, a configuration without the seal 14 may be employed.

1, 41 Electrical stimulation electrode assembly 10 Main body 11 First sheath 12 Second sheath 13 Connector 14 Seal 15 Easy cutting part (separation part)
20 Electrode portion 30, 50, 60, 70, 80 Energizing portion 31, 32, 51, 52, 53, 61, 62, 71, 81A, 82 Energizing member 42 Wiring 42A Extra length portion 43 Second seal

Claims (5)

An electrical stimulation electrode assembly placed in a blood vessel,
An insulating body having a tubular first sheath and a tubular second sheath inserted into the first sheath;
An electrode having an electrode surface exposed; an electrode portion provided on a tip side of the main body; and
An urging member comprising an elastic body, and an urging portion for urging the electrode portion toward the wall surface of the blood vessel;
With
The electrical stimulation electrode assembly, wherein the first sheath and the second sheath are relatively movable in the longitudinal direction and relatively rotatable about an axis.   2. The electrical stimulation according to claim 1, further comprising a separation portion that is provided at an intermediate portion in the longitudinal direction of the first sheath and separates the first sheath into a distal end region and a proximal end region. Electrode assembly. A connector provided on the first sheath and connected to the stimulation generator;
Wiring for electrically connecting the electrode and the connector;
Further comprising
The electrical stimulation electrode assembly according to claim 1, wherein the wiring has an extra length portion that is wound so as to form a plurality of loops.   A lumen of the first sheath, further comprising a seal that is disposed between the inner surface of the first sheath and the outer surface of the second sheath, and suppresses blood intrusion into the main body. The electrical stimulation electrode assembly according to any one of claims 1 to 3.   5. The second sheath according to claim 1, further comprising a second seal that is a lumen of the first sheath and is provided on a proximal end side with respect to the seal, and suppresses blood intrusion into the connector. The electrical stimulation electrode assembly as described in any one of Claims.

Images