JP2016140716A - Medical electrostimulation electrodes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide medical electrostimulation electrodes the electrode support for which can be reduced in the outer diameter when the electrodes are withdrawn.SOLUTION: Medical electrostimulation electrodes 1 inserted into a blood vessel and used to stimulate nerves from inner walls of the blood vessel, comprise: stimulating electrode parts 10, 11 for providing electrical stimulations through inner walls of a blood vessel; a linear lead part 20 for insertion of a wiring electrically connected to the stimulating electrode parts; and an electrode support 25 which is formed of linear elastic members 26A, 26B, 26C in a shape of a cage substantially rotationally symmetrical about a certain axis C, and has stimulating electrode parts in portions of the elastic members, and one end of which in an axial direction is connected to an end of the lead part. The electrode support is formed so as to protrude radially outwardly from outer surfaces of the elastic members and has a plurality of projecting parts 30 in different positions in the axial direction when the diameter of the electrode support is reduced.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a medical electrical stimulation electrode that applies electrical stimulation to nerves.

2. Description of the Related Art Conventionally, stimulation generators that perform treatment by applying electrical stimulation to biological tissue (linear tissue) such as nerve tissue or muscle are known. Examples of such a stimulus generator include a nerve stimulator, a pain relieving device, an epilepsy treatment device, and a muscle stimulator.
These stimulation generators may be used with medical electrical stimulation electrodes embedded in a living body in order to bring medical electrical stimulation electrodes that transmit electrical stimulation into close contact with a target to be stimulated in the living body.

As this type of medical electrical stimulation electrode, for example, Patent Document 1 discloses a conductive lead body (lead portion) having a proximal end configured to be connected to a pulse generator, and an electric pulse across a blood vessel wall. A tip portion having at least one electrode (stimulation electrode portion) configured to be fed and a lead anchor (electrode support) having an expanded shape are provided. The lead anchor is configured to expand from a folded folded shape to a pre-shaped expanded shape. When in the folded shape, the tip has an effective length that is substantially equal to the effective length of the folded lead anchor.
The leading end of the lead body is coupled to the outside of the lead anchor. When in the expanded shape, the lead anchor presses the distal end portion of the lead body against the blood vessel wall, and the distal end portion of the lead body is deployed and fixed in the blood vessel. The lead anchor may be formed from a laser cut tube of superelastic material.

  In Patent Document 1, when the lead anchor to which the tip is attached reaches the stimulation site in the blood vessel adjacent to the nerve to be stimulated, the lead anchor expands and the tip attached to the outside of the lead anchor. Is brought into frictional engagement with the wall of the blood vessel in which the tip including the lead anchor is expanded.

Special table 2010-516405 gazette

Patent Document 1 includes the following two points as means for moving to a stimulation position.
1) The lead anchor is folded and advanced through the patient's vasculature using a guide member such as a guide catheter and arrives at the stimulation site.
2) The tip can be repositioned by reintroducing a guide member such as a guide catheter or guidewire and folding the lead anchor (partially or completely).
As described in 1) and 2) above, it is disclosed that the lead anchor is folded. At this time, the shape of the lead anchor (wire knitted structure) when folded is sufficiently thin with respect to the blood vessel diameter. It is required to become.

In the lead anchor as shown in Patent Document 1, in order to prevent the lead anchor from being displaced in the blood vessel, the lead anchor protrudes from the outer surface of the super elastic wire (elastic member) constituting the lead anchor. Providing convex portions has been studied.
After the medical electrical stimulation electrode is placed for a certain period of time, it is desired to reduce the outer diameter of the lead anchor and remove it from the body when collecting the medical electrical stimulation electrode. However, when the lead anchor is reduced in diameter, the outer diameter of the lead anchor is unlikely to be reduced if the positions of the convex portions in the axial direction of the lead body overlap.

  This invention is made | formed in view of such a problem, Comprising: It aims at providing the medical electrical stimulation electrode which can make the outer diameter of an electrode support body smaller when collect | recovering.

In order to solve the above problems, the present invention proposes the following means.
The medical electrical stimulation electrode of the present invention is a medical electrical stimulation electrode used by being inserted into the blood vessel in order to stimulate nerves from the inner wall of the blood vessel, and for applying electrical stimulation through the inner wall of the blood vessel. The stimulating electrode part, a linear lead part through which the wiring electrically connected to the stimulating electrode part is inserted, and a linear elastic member are formed in a bowl shape that is substantially rotationally symmetric around a certain axis. An electrode support body having the stimulation electrode part in a part of the elastic member and having one end part in the axial direction connected to an end part of the lead part. It is formed so as to protrude outward in the radial direction of the electrode support from the outer surface, and has a plurality of convex portions arranged at different positions in the axial direction when the diameter of the electrode support is reduced. Yes.

Further, in the above-described medical electrical stimulation electrode, the electrode support has a plurality of intersections where the pair of elastic members intersect and are connected, and the electrode support has a reduced diameter at the plurality of intersections. It is more preferable that they are arranged at different positions in the axial direction.
In the medical electrical stimulation electrode, it is more preferable that the intersecting portion is formed by joining a pair of elastic members to each other.
The medical electrical stimulation electrode preferably further includes a recovery sheath through which the lead portion is inserted and the reduced diameter electrode support is inserted.

  According to the medical electrical stimulation electrode of the present invention, the outer diameter of the electrode support can be made smaller when the electrode is recovered.

It is a schematic diagram which shows the whole structure of the medical electrical stimulation electrode of 1st Embodiment of this invention. It is a principal part enlarged view in FIG. It is an A1 direction arrow directional view in FIG. It is a typical perspective view showing the composition of the elastic member of the medical electrical stimulation electrode. It is an A2 direction arrow line view in FIG. It is an A3 direction arrow line view in FIG. It is an A4 direction arrow line view in FIG. It is an A5 direction arrow line view in FIG. It is sectional drawing of the side surface of the elastic member of the medical electrical stimulation electrode. FIG. 10 is a cross-sectional view taken along section line A7-A7 in FIG. It is sectional drawing of the side surface of the convex part of the medical electrical stimulation electrode. It is sectional drawing of the cutting line A8-A8 in FIG. It is sectional drawing which shows the state by which the electrode support body was inserted in the collection | recovery sheath of the medical electrical stimulation electrode. It is a figure which shows the example of the stimulation pulse which the electrical stimulation apparatus used with the medical electrical stimulation electrode uses. It is a schematic diagram which shows the state which inserted the electrode support body in the superior vena cava explaining the procedure which indwells the electrical stimulation electrode for medical treatment. It is a side view of the principal part of the medical electrical stimulation electrode of 2nd Embodiment of this invention. It is an A10 direction arrow line view in FIG. It is sectional drawing which shows the state by which the electrode support body was inserted in the collection | recovery sheath of the medical electrical stimulation electrode. It is a side view of the principal part of the medical electrical stimulation electrode of 3rd Embodiment of this invention. It is an A11 direction arrow directional view in FIG. It is sectional drawing which shows the state by which the electrode support body was inserted in the collection | recovery sheath of the medical electrical stimulation electrode.

(First embodiment)
A first embodiment of a medical electrical stimulation electrode (hereinafter also abbreviated as “electric stimulation electrode”) according to the present invention will be described below with reference to FIGS. 1 to 15. The electrical stimulation electrode of this embodiment is used by being inserted into a blood vessel in order to stimulate nerves from the inner wall of the blood vessel.
As shown in FIG. 1, the electrical stimulation electrode 1 includes stimulation electrode portions 10 and 11 for applying electrical stimulation through an inner wall of a blood vessel, and wiring 35 (described later) electrically connected to the stimulation electrode portions 10 and 11. A linear lead portion 20 that is inserted therethrough, an electrode support 25 that is formed in a bowl shape that is substantially rotationally symmetric about a certain axis C by linear elastic members 26A, 26B, and 26C; An operation sheath 50 through which the portion 20 is inserted and a recovery sheath 60 are provided. The electrical stimulation electrode 1 is used together with the electrical stimulation apparatus 100 that applies a stimulation pulse to the electrical stimulation electrode 1, and the electrical stimulation system 2 is configured by the electrical stimulation electrode 1 and the electrical stimulation apparatus 100.
Hereinafter, the electrode support 25 side with respect to the lead portion 20 is referred to as a distal end side, and the lead portion 20 side with respect to the electrode support 25 is referred to as a proximal end side.

The lead portion 20 includes a lead body 21 formed in a tubular shape from a biocompatible material such as polyamide resin, and a proximal-side cross block 22 provided at the tip of the lead body 21.
The lead body 21 has an outer diameter of 1 to 2 mm and a total length of about 500 mm. A wiring 35 is inserted into the conduit of the lead main body 21. The wiring 35 is a stranded wire made of a nickel-cobalt alloy (35NLT 28% Ag material) having bending resistance and is covered with an electrically insulating material (ETFE [tetrafluoroethylene-ethylene copolymer resin] etc. having a thickness of 20 μm). Used.
The proximal cross block 22 is formed in a hexagonal prism shape, for example, from titanium. A through hole (not shown) is formed at the center of the proximal cross block 22, and the aforementioned wiring 35 is inserted into the through hole.
Needless to say, it is effective to apply an antithrombotic coating to the surfaces of the lead body 21 and the proximal cross block 22.
Although not shown, an electrical connector that can be attached to and detached from the electrical stimulation device 100 is provided at the proximal end portion of the lead body 21. The aforementioned wiring 35 is connected to this electrical connector.

As shown in FIGS. 2 and 3, in this embodiment, the electrode support 25 surrounds the elastic members 26A, 26B, and 26C around an axis C obtained by extending the central axis of the proximal cross block 22 toward the distal end. It is formed in a bowl shape having a rotational symmetry around the axis C, in other words, a basket shape. The saddle shape referred to here means a shape of a side surface of a cone having a cylindrical shape on the distal end side and a smaller outer diameter on the proximal end side toward the proximal end side. The elastic members 26A, 26B, and 26C are provided with a plurality of convex portions 30 that protrude from the outer peripheral surfaces (outer surfaces) of the elastic members 26A, 26B, and 26C.
The elastic members 26A, 26B, and 26C have the same shape except that the stimulating electrode portions 10 and 11 are disposed only on the elastic member 26A and the position where the convex portion 30 is provided. .

In the following, unless otherwise specified, the shape of the elastic member 26A will be described by adding a capital letter “A” to the numerals and lowercase letters as symbols, and the description of the elastic members 26B and 26C The uppercase letters “B” and “C” are added to the lowercase letters, and the description is omitted.
For example, a bent portion 27fB (27fC) in the elastic member 26B (26C) indicates a portion having the same shape corresponding to the bent portion 27fA in the elastic member 26A.

The elastic member 26A is a member in which a three-dimensional loop shape is formed by bending a single linear member having elasticity. Hereinafter, the natural state shape of the elastic member 26A alone will be described with reference to FIGS. Here, the natural state of the elastic member 26A alone is a state in which an external force does not act on the elastic member 26A or a deformation can be ignored even if it acts.
As shown in FIGS. 4 to 6, the elastic member 26A has a connecting end 26aA, a proximal end linear portion 26bA, a bent portion 27fA, a distal end side linear portion 26cA, a bent portion 27hA, from one end portion to the other end portion. The proximal end side linear portion 26dA and the connecting end portion 26eA are provided in this order.

The connecting end portions 26 a </ b> A and 26 e </ b> A are portions for fixing the elastic member 26 </ b> A to the proximal cross block 22 and engaging with the lead body 21 via the proximal cross block 22. The connecting end portions 26aA and 26eA are each linearly extended along the first axis O1, and are arranged in parallel and close to each other across the first axis O1.
The coupling end portions 26aA and 26eA are arranged so that the first axis O1 is parallel to the axis C.
The fixing method of the connection end portions 26aA and 26eA and the proximal-side intersection block 22 is not particularly limited, and for example, the fixing method such as adhesion, welding, or caulking is appropriately selected according to the material of the proximal-side intersection block 22. be able to.

The proximal-side linear portions 26bA and 26dA include the first axis O1, and are arranged in line symmetry with respect to the first axis O1 in a plane S2 passing through the central axis of the coupling end portions 26aA and 26eA. It is the part made into the shape.
That is, as shown in FIG. 5, the base end side linear portions 26bA and 26dA extend obliquely from the end portions connected to the connecting end portions 26aA and 26eA so as to be separated from each other toward the distal end side. Are gradually separated from the first axis O1. In the vicinity of the distal end side end portions of the base end side linear portions 26bA and 26dA, the base end side linear portions 26bA and 26dA are substantially parallel to the first axis O1 (including a parallel case).

The proximal-side linear portion 26bA can be configured by a curved portion that protrudes in a direction away from the first axis O1, a broken line portion, or a combination of the curved portion and the broken line portion.
In the present embodiment, as an example, the shape of the proximal-side linear portion 26bA is such that the proximal-side region b1 near the coupling end portion 26aA has a first axis O1 as compared to the distal-side region b2 near the distal-side linear portion 26cA. The curve shape in which the average rate of change of the slope with respect to is larger is adopted.
The proximal side linear portion 26dA is configured in the same manner as the proximal side linear portion 26bA.
In this embodiment, the base end side linear portions 26bA and 26dA adopt a shape that is inclined so as to be separated from each other toward the distal end side. For this reason, the distal end side end portions of the base end side linear portions 26bA and 26dA are portions having the maximum width in the direction orthogonal to the first axis O1 of the elastic member 26A in the natural state.

As shown in FIG. 4, the bent portion 27hA is located on the side opposite to the distal end side linear portion 26cA with respect to the plane S2 between the distal end portion of the proximal end linear portion 26dA and the proximal end portion of the distal end side linear portion 26cA described later. It is the site | part formed in the U shape which protrudes toward.
In the present specification, the “U-shape” is not limited to a shape in which two parallel straight portions are connected by an arcuate curved portion. For example, the two straight portions may be parallel and non-parallel, and the curved portion may be curved with a curve other than the arc. Further, the curved portion may be configured by a straight line or a broken line made of a curved line, or a shape formed by one straight portion bent at the end of two straight portions as in the present embodiment shown in FIG. (U shape) may be sufficient.
The bent portion 27hA of the present embodiment includes a first portion h1, a second portion h2, and a third portion h3.

The first portion h1 is a linear portion that is bent at the distal end portion of the proximal-side linear portion 26dA. The first portion h1 may be linear or curved, but in the present embodiment, it is linear as an example.
The bending angle φ1 of the first portion h1 is preferably in the range of 90 ° ± 30 °, and the length is longer than the longitudinal direction of the stimulation electrode portion 10, and is preferably 4.5 mm to 7.0 mm, for example.
Here, the bending angle φ1 is a smaller angle among the angles formed by the first portion h1 and the distal end portion of the proximal end side linear portion 26dA.

The second part h2 is a bent linear part at the end in the protruding direction of the first part h1, and is located on the extension line of the base-side linear part 26dA when viewed from the normal direction of the plane S2 (FIG. 5) in parallel with the plane S2. The second portion h2 may be linear or curved, but in the present embodiment, is linear as an example.
The length of the second portion h2 is preferably, for example, 3.0 mm to 7.0 mm.

The third portion h3 is a linear portion that is bent at the end portion in the extending direction of the second portion h2 and connected to the proximal end portion of the distal end side linear portion 26cA. The third portion h3 may be linear or curved, but in the present embodiment, is linear as an example.
The bending angle φ2 of the third portion h3 is preferably in the range of 90 ° ± 30 °.
Here, the bending angle φ2 is the smaller of the angles formed by the third portion h3 and the second portion h2.
In the present embodiment, the distal end portion of the third portion h3 is located on the plane S2.

In the bent portion 27hA having such a configuration, the stimulation electrode portion 11 is disposed on the first portion h1, and the stimulation electrode portion 10 is disposed on the third portion h3. That is, the stimulation electrode portions 10 and 11 are formed in the bent portion 27hA.
The stimulation electrode portion 11 is disposed at the intermediate portion of the first portion h1 so that the longitudinal direction thereof is along the central axis direction of the first portion h1. The stimulation electrode portion 10 is disposed in the middle portion of the third portion h3 so that the longitudinal direction thereof is along the central axis direction of the third portion h3.
The detailed configuration of the stimulation electrode portions 10 and 11 will be described after the elastic member 26A is described.

Next, the bent portion 27fA of the elastic member 26A will be described.
As shown in FIG. 8, the bent portion 27fA has a distal end with respect to the plane S2 between the distal end portion of the proximal end side linear portion 26bA and the proximal end portion of the distal end side linear portion 26cA described later, similarly to the bent portion 27hA. It is a portion formed in a U shape projecting on the opposite side to the side linear portion 26cA.
The bent portion 27fA of the present embodiment includes a first portion f1, a second portion f2, and a third portion f3.
The outer shape of the bent portion 27fA may be different from the bent portion 27hA provided at a position facing the plane S1 including the first axis O1 and perpendicular to the plane S2 (see FIG. 4). The plane S1 has a shape symmetrical to the bent portion 27hA.
That is, the first part f1, the second part f2, and the third part f3 have the same outer shape as the first part h1, the second part h2, and the third part h3 in the bent portion 27hA, respectively.
However, unlike the bent portion 27hA, the bent electrode portion 27fA is not provided with the stimulation electrode portions 10 and 11.

As shown in FIG. 4, the distal end side linear portion 26cA is a convex projecting toward the side of the plane S2 from the distal end portions of the third portions f3 and h3 in the bent portions 27fA and 27hA further toward the distal end side. It is a part curved in a shape.
In the present embodiment, as an example, the distal end side linear portion 26cA is disposed on a plane S3 that includes the third axis O3 in the plane S2 and intersects the plane S2 at an angle θ and is plane-symmetric with respect to the plane S1. It is formed in a C shape.
Here, the third axis O3 is an axis that is in the plane S2 and passes through the tip portions of the third portions f3 and h3 and is orthogonal to the first axis O1.
For this reason, the top portion 26gA of the distal end side linear portion 26cA is formed at a position where the second axis O2 formed by the intersection of the planes S1 and S3 intersects the distal end side linear portion 20cA.
The angle θ of the plane S3 is preferably 5 ° or greater and 90 ° or less.

The distal end side linear portion 26cA can be configured by a curved portion, a broken line portion, or a combination of the curved portion and the broken line portion that protrudes in a direction away from the third axis O3.
In the present embodiment, as shown in FIG. 5, the shape of the distal end side linear portion 26cA is, for example, the second end portion of the bent portion 27fA (27hA) in the proximal end region c1 (c3) close to the bent portion 27fA (27hA). The three portions f3 (h3) are extended in a curved line shape or a straight line shape that is inclined toward the plane S1 from the tip side end portion.
Moreover, in the front end side area | region c2 between base end side area | regions c1 and c3, it has the mountain shape which makes apex 26gA a vertex. The mountain shape in the distal end side region c2 can be, for example, a mountain shape made of a curve such as an arc or an elliptical arc, or a mountain shape formed by a plurality of broken lines. In the present embodiment, as an example, a curved shape in which the curvature of the top portion 26gA is maximized and a bent portion is formed in the vicinity of the top portion 26gA is adopted.

With such a configuration, the elastic member 26 </ b> A has a shape symmetrical with respect to the plane S <b> 1 except for the stimulation electrode portions 10 and 11 and the convex portion 30.
Here, the internal structure of the elastic member 26A and the configurations of the stimulation electrode portions 10 and 11 and the convex portion 30 will be described.

As shown in FIGS. 9 and 10, the elastic member 26 </ b> A is configured by a linear body in which the outer peripheral surface of the wire portion 33 is covered with a coating 34 having electrical insulation.
In this embodiment, the cross section orthogonal to the longitudinal direction of the wire part 33 is formed in a rectangular shape of 0.3 mm square, for example. As the wire portion 33, a shape memory alloy, a super elastic wire, or the like can be used.
The cross section orthogonal to the longitudinal direction of the outer peripheral surface of the coating 34 is circular. The outer diameter of the coating 34 is, for example, 0.8 mm. As a material suitable for the coating 34, for example, a polyamide resin can be employed.

The stimulation electrode part 10 is formed in a cylindrical shape with a biocompatible metal such as a platinum iridium alloy. The dimensions of the stimulation electrode unit 10 are, for example, an outer diameter of 0.8 mm and a length of 4 mm. The stimulation electrode portion 10 has an outer peripheral surface exposed to the outside from the coating 34 over the entire circumference. That is, the outer peripheral surface of the stimulation electrode unit 10 and the outer peripheral surface of the coating 34 are flush with each other. The stimulation electrode unit 10 and the wire unit 33 are insulated by a coating 34. In order to ensure insulation between the coating 34 and the wire portion 33, a resin insulating member may be provided between the stimulation electrode portion 10 and the wire portion 33.
The aforementioned wiring 35 is electrically connected to the inner peripheral surface of the stimulation electrode portion 10 by welding or the like. The wiring 35 is disposed in the covering 34 and extends along the wire portion 33, and extends from the base end portion of the connecting end portion 26eA to the lead portion 20 side.
The stimulation electrode unit 11 has the same configuration as the stimulation electrode unit 10. As described above, the stimulation electrode portions 10 and 11 are formed on the elastic member 26A, and the stimulation electrode portions 10 and 11 are provided in part of the elastic member 26A. The stimulation electrode unit 10 and the stimulation electrode unit 11 are arranged at least 3 mm to 8 mm apart from each other.

As shown in FIGS. 11 and 12, the convex portion 30 is formed in a cylindrical shape with the same material as the coating 34 in this embodiment. The dimensions of the convex portion 30 are, for example, an outer diameter of 1.0 mm and a length of 1 mm to 3 mm. In this example, the length L from which the convex part 30 protrudes from the outer peripheral surface of the coating 34 is 0.1 mm. The convex portion 30 is formed so as to protrude from the outer peripheral surface of the elastic member 26A over the entire circumference of the elastic member 26A.
The convex portion 30 is fixed to the outer peripheral surface of the coating 34 by fusion bonding or the like.
In this embodiment, as shown in FIGS. 2 and 3, for example, three protrusions 30 are formed on the elastic member 26A.
Three convex portions 30 are formed on the elastic member 26B and the elastic member 26C, respectively. However, the locations where the protrusions 30 are formed in the elastic members 26A, 26B, and 26C are different from each other.

The elastic members 26 </ b> A, 26 </ b> B, 26 </ b> C configured in this manner have elasticity due to the wire portion 33 and the like. The elastic members 26A, 26B, and 26C are arranged such that each first axis O1 overlaps the axis C, and the top portions 26gA, 26gB, and 26gC are spaced apart at equal intervals (120 ° intervals) in the circumferential direction with respect to the axis C. Has been.
When each elastic member 26A, 26B, 26C is viewed from the front end side shown in FIG. 3 so that the protruding direction of each front end side linear portion 26cA, 26cB, 26cC is directed radially outward with respect to the axis C, The elastic members 26A, 26B, and 26C are arranged in the clockwise order.

As shown in FIGS. 2 and 3, the base end side linear portion 26bA and the base end side linear portion 26dB, the base end side linear portion 26bB and the base end side linear portion 26dC, the base end side linear portion 26bC and the base end side linear portion 26dA. Are arranged at positions facing each other with a gap in the circumferential direction. Accordingly, the bent portion 27fA and the bent portion 27hB, the bent portion 27fB and the bent portion 27hC, and the bent portion 27fC and the bent portion 27hA are positioned so that the U-shaped openings face each other. The overhanging portion 40 is configured by the bent portion 27fA and the bent portion 27hB. Similarly, the overhanging portion 41 is constituted by the bent portion 27fB and the bent portion 27hC, and the overhanging portion 42 is constituted by the bent portion 27fC and the bent portion 27hA.
The overhang portions 40, 41, and 42 are portions that restrain the positional deviation of the electrode support 25 by stretching in the blood vessel when the electrode support 25 is disposed in the blood vessel.

Adjacent elastic members 26A, 26B, and 26C cross each other, and elastic member 26A and elastic member 26B, elastic member 26B and elastic member 26C, and elastic member 26C and elastic member 26A intersect with each other at the elastic member fixing portion ( (Intersection) 38. The elastic member fixing portion 38 is formed by joining the coverings 34 of the elastic members 26A, 26B, and 26C to each other by fusion bonding.
Three elastic member fixing portions 38 are provided on the electrode support 25.
Nine convex portions 30 are formed on the electrode support 25. The outer diameter of the electrode support 25 in the natural state is larger than the inner diameter of a blood vessel such as the superior vena cava in which the electrode support 25 is placed, for example, 35 mm. The length of the electrode support 25 in the direction of the axis C is 35 mm.
At least some of the nine protrusions 30 protrude outward in the radial direction of the electrode support 25 from the outer surfaces of the elastic members 26A, 26B, and 26C.

As shown in FIG. 2, in the natural state of the electrode support 25, the nine convex portions 30 are arranged at different positions in the axis C direction. The nine convex portions 30 referred to here are arranged at different positions in the axis C direction. In the axis C direction, one convex portion 30 and the other eight convex portions 30 other than the one convex portion 30. It means that there is no overlapping part. This condition is satisfied even when any one of the nine protrusions 30 is selected.
In the natural state of the electrode support 25, the three elastic member fixing portions 38 are disposed at the same position in the axis C direction, and the three overhang portions 40, 41, 42 are disposed at the same position in the axis C direction.

The base end portions (one end portion in the direction of the axis C) of the elastic members 26A, 26B, and 26C of the electrode support 25 are welded, bonded, or crimped to the proximal cross block 22 (end portion) of the lead portion 20. Connected by.
As shown in FIG. 13, the electrode support 25 configured in this way is inserted into the recovery sheath 60 and the nine protrusions 30 are located at different positions in the axis C direction when the diameter of the electrode support 25 is reduced. Placed in. The diameter of the electrode support 25 referred to here means that each configuration of the electrode support 25 approaches the axis C over the entire circumference and the electrode support 25 has a minimum diameter.
The inner diameter of the recovery sheath 60 is 3 mm, for example. In this case, the outer diameter of the electrode support 25 is 35 mm to 3 mm, being 1/35/3 (about 11.7 or less of 1/10) by being inserted into the recovery sheath 60. . When the electrode support 25 is inserted into the recovery sheath 60, the wire portions 33 of the elastic members 26A, 26B, and 26C are folded back so that the six wire portions 33 are closely packed.

As shown in FIG. 1, the operation sheath 50 includes a sheath body 51 formed in a tubular shape, an engagement portion 52 provided at the distal end portion of the sheath body 51, and a connector provided at the proximal end portion of the sheath body 51. 53.
The sheath body 51 is, for example, an ETFE tubular member having an outer diameter of about 4 mm and a total length of about 400 mm. The sheath body 51 can be torn (peel away) by forming a groove or the like (not shown) extending in the direction of the axis C on the outer peripheral surface. The lead portion 20 is inserted into the sheath body 51 so as to be able to advance and retract in the direction of the axis C.
Although not shown, the engaging portion 52 is formed in a hexagonal column shape and has a through hole extending in the direction of the axis C. When the proximal cross block 22 is inserted into the through hole, the inner peripheral surface of the through hole and the outer peripheral surface of the proximal cross block 22 are engaged in the circumferential direction.
An O-ring 54 is attached to the inner peripheral surface of the connector 53. The lead portion 20 is inserted into the O-ring 54 so as to be able to advance and retract in the direction of the axis C. The space between the O-ring 54 and the lead portion 20 is kept watertight.

The recovery sheath 60 includes a sheath body 61 formed in a tubular shape and a hub 62 formed in a tubular shape and provided at the proximal end portion of the sheath body 61.
The sheath body 61 is an ETFE tubular member having an outer diameter of about 4 mm, an inner diameter of about 3 mm, and a total length of about 400 mm, for example. The lead portion 20 is inserted into the sheath body 61 and the hub 62 so as to be able to advance and retract in the direction of the axis C.
An O-ring 63 is attached to the inner peripheral surface of the hub 62. The lead portion 20 is inserted into the O-ring 63 so as to be able to advance and retract in the axis C direction. The space between the O-ring 63 and the lead portion 20 is kept watertight.
One end of a tube 64 is connected to the hub 62. The conduit of the tube 64 communicates with the conduit of the sheath body 61 through the cylindrical hole of the hub 62. A general connector 65 such as a luer lock connector is provided at the other end of the tube 64. Although not shown, the syringe of the syringe piston pump can be attached to and detached from the connector 65.
The recovery sheath 60 serves as a guide for reducing the diameter of the electrode support 25.

  In the electrical stimulation apparatus 100, as shown in FIG. 14, stimulation pulses that are biphasic waveforms of a constant current method or a constant voltage method are generated with a predetermined interval. For example, a stimulation pulse having a frequency of 20 Hz and a pulse width of 50 to 400 μsec and a plus several volts to minus several volts is generated for 3 to 20 seconds (sec) per minute (60 sec).

Next, a treatment (procedure) for placing the electrode support 25 of the electrical stimulation electrode 1 configured as described above in the superior vena cava will be described.
Outside the patient's body, the operating sheath 50 is moved (pushed) toward the distal end side with respect to the lead portion 20, and the through hole of the engaging portion 52 of the operating sheath 50 is engaged with the proximal cross block 22. An electrocardiograph for measuring heart rate is attached to the patient.
As shown in FIG. 15, a small incision is made near the neck P1 of the patient P to form an opening P2. A known introducer (not shown) is attached to the opening P2. This introducer can be torn like the operation sheath 50.

The electrode support 25 is inserted into the right external jugular vein (blood vessel) P3 through the introducer. At this time, the electrode support 25 is inserted after being elastically deformed (reduced diameter) to an outer diameter that can be inserted into the introducer. At the time of insertion, the positions of the stimulation electrode portions 10 and 11 of the electrical stimulation electrode 1 and the wire portion 33 of the electrode support 25 are confirmed under X-ray fluoroscopy.
In the present embodiment, the electrode support 25 is introduced into the superior vena cava from the right external jugular vein P3. However, the electrode support 25 is not limited to the right external jugular vein P3, but the right internal jugular vein, the left external jugular vein, the left It may be introduced into the superior vena cava from the internal jugular vein, the right subclavian vein, and the left subclavian vein.

If necessary, a syringe piston pump syringe is connected to the connector 65 of the electrical stimulation electrode 1. An anticoagulant such as heparin is accommodated in the syringe, and the piston is pushed into the syringe. The anticoagulant is released to the distal end side of the sheath body 61 through the connector 65, the tube 64, and the hub 62.
The released anticoagulant rides on the blood flow and diffuses in the vicinity of the lead portion 20 and the electrode support 25, and the occurrence of thrombus can be reduced where the lead portion 20 and the electrode support 25 are located.

When the surgeon grasps and pushes the proximal end side of the lead portion 20, the applied force is transmitted to the electrode support 25 via the lead body 21 and the proximal cross block 22. When the proximal end side of the operation sheath 50 is rotated around the central axis C <b> 1, the applied force is transmitted to the electrode support 25 via the sheath body 51, the engagement portion 52, and the proximal cross block 22. .
When the lead portion 20 is pushed in, the electrode support 25 protrudes from the introducer to the distal end side, and the electrode support 25 is introduced into the right external jugular vein P3. By using the introducer, the electrode support 25 can be inserted into the right external jugular vein P3 with minimal invasiveness.
When the electrode support 25 is introduced into the right external jugular vein P3, the electrode support 25 is reduced in diameter and pushed in the direction of the axis C by being pushed by the blood vessel wall. Thereby, the outer diameter of the electrode support body 25 becomes smaller than the outer diameter in a natural state.

The surgeon pushes the lead portion 20 under fluoroscopy and roughly installs the electrode support 25 in the superior vena cava (blood vessel) P5 as shown in FIG. Since the outer diameter of the electrode support 25 in the natural state is set as described above, when the electrode support 25 is placed in the superior vena cava P5, the inner wall of the superior vena cava P5 is elastic member 26A, By energizing 26B and 26C, the electrode support 25 is fixed in the superior vena cava P5. Furthermore, since the convex portion 30 is provided on the electrode support 25, the convex portion 30 is locked to the inner surface of the superior vena cava P5, and the electrode support 25 is more securely fixed in the superior vena cava P5. .
Adjacent to the superior vena cava P5, the vagus nerve (nerve) P6 to be stimulated is running in parallel on the back side of the superior vena cava P5.

  The electrical connector of the lead part 20 is attached to the electrical stimulation device 100, and the stimulation pulse generated by the electrical stimulation device 100 is transmitted via the electrical connector and the wiring 35, so that the stimulation electrode unit 10 and the stimulation electrode unit 11 are connected. Apply electrical stimulation with stimulation pulses. In this example, the nerve stimulation signal is applied so that the distal stimulation electrode portion 10 near the heart P7 functions as a minus (−) pole and the proximal stimulation electrode portion 11 functions as a plus (+) pole. .

Next, the positions and orientations of the stimulation electrode portions 10 and 11 in the superior vena cava P5 are adjusted so that the heart rate of the patient P decreases. Specifically, the surgeon operates the proximal end side of the lead portion 20 to push in the lead portion 20 or pull back the lead portion 20 to return the electrode support 25 in the superior vena cava P5, that is, the stimulation electrode portion 10. , 11 in the direction of the axis C.
Further, the operation sheath 50 is rotated around the axis C to adjust the circumferential direction of the electrode support 25. While adjusting the position and orientation, the heart rate of the patient P is measured by an electrocardiograph. When the stimulation electrode portions 10 and 11 are arranged so as to approach and face the vagus nerve P6 and the electrical stimulation applied to the vagus nerve P6 becomes the largest, the heart rate of the patient P is the lowest. If the positions and orientations of the stimulation electrode portions 10 and 11 are adjusted so that the stimulation electrode portion 10 functioning as a negative pole is on the vagus nerve P6, stimulation can be performed efficiently. Thus, the optimal stimulation position of the stimulation electrode portions 10 and 11 can be easily obtained.
The surgeon adjusts the positions and orientations of the stimulation electrode portions 10 and 11 so that the heart rate decreases most, that is, the stimulation electrode portions 10 and 11 face the vagus nerve P6 side.

When the positions and orientations of the stimulation electrode portions 10 and 11 are determined, the electrode support 25 of the electrical stimulation electrode 1 is placed in the superior vena cava P5. At this time, the proximal end portion of the lead portion 20 and the proximal end portion of the operation sheath 50 are exposed to the outside from the neck portion P1 of the patient P.
Specifically, the operator pulls back only the operation sheath 50 while holding the lead portion 20 and retracts, thereby releasing the engagement between the proximal cross block 22 and the engagement portion 52 of the operation sheath 50.
The operation sheath 50 and the introducer are torn and removed from the lead portion 20.
The distal end side of the recovery sheath 60 is inserted into the right external jugular vein P3 through the opening P2 of the neck P1. The hub 62 of the recovery sheath 60 is fixed to the skin of the neck P1 by threading or taping. By doing in this way, a clean area | region and an unclean area | region can be distinguished and an infectious disease etc. can be prevented. In addition, you may insert the collection | recovery sheath 60 in the right external jugular vein P3 simultaneously with removing an introducer.
In this state, the electrode support 25 is placed in the superior vena cava P5 while generating a stimulation pulse by the electrical stimulation apparatus 100 and applying electrical stimulation for a certain period.

After applying electrical stimulation for a certain period of time, the electrical stimulation device 100 is operated to stop the generation of stimulation pulses, and the electrical stimulation electrode 1 is started to be removed. It should be noted that no surgical re-operation is required to remove the electrical stimulation electrode 1.
First, the fixation of the skin of the neck P1 and the hub 62 is released by cutting a thread or the like. The lead portion 20 is pulled back to the proximal end side with respect to the recovery sheath 60, and the electrode support 25 is accommodated in the sheath body 61 of the recovery sheath 60 as shown in FIG. At this time, since the nine convex portions 30 are arranged at different positions in the axis C direction, it is possible to suppress an increase in the outer diameter of the reduced diameter electrode support body 25 at any position in the axis C direction. . The force for folding the electrode support 25 so as to reduce the diameter at the time of extraction (the force for pulling the electrode support 25 into the collection sheath 60) is dispersed in the direction of the axis C. Therefore, the operability of the electrical stimulation electrode 1 is improved.

The recovery sheath 60 and the electrode support 25 are pulled out from the right external jugular vein P3. By adopting such a procedure, the electrode support 25 does not spread or damage the blood vessel wall in the vicinity of the opening P2 when the electrode support 25 is removed. Can be removed safely.
After the electrical stimulation electrode 1 is removed, general hemostasis treatment such as suturing and compression is performed on the skin of the neck P1, and a series of treatments is completed.

As described above, according to the electrical stimulation electrode 1 of the present embodiment, when the electrode support 25 is reduced in diameter, the nine convex portions 30 are arranged at different positions in the axis C direction.
The electrode support 25 is housed in the recovery sheath 60 and then recovered (removal is performed). If the convex portion 30 is formed at the same position in the axis C direction, the diameter of the electrode support 25 is reduced. Is strongly required (the force for pulling the electrode support 25 into the recovery sheath 60). In order to reduce this and disperse the folding force when the electrode support 25 is collected, the formation position of the convex portion 30 is prevented from overlapping with the direction of the axis C when folded. As a result, when folded, the shape of the electrode support 25 can be changed to the smallest diameter. Therefore, the outer diameter of the electrode support 25 can be made smaller when it is collected.

The elastic member fixing portion 38 is formed by joining a pair of elastic members 26A, 26B, and 26C by melt bonding. Since the position of the elastic member fixing portion 38 is fixed on the elastic members 26A, 26B, and 26C, the elastic member fixing portion 38 does not move when it is folded so as to reduce the diameter, and the elastic member fixing portion 38 does not move. There will be no overlap and the folding force will not increase.
Since the electrical stimulation electrode 1 includes the recovery sheath 60, the electrode support 25 can be stored in a reduced size within the recovery sheath 60, and a portion that rubs against the living tissue can be stored in the recovery sheath. 60 smooth inner peripheral surfaces can be obtained. The electrode support 25 can be safely recovered outside the body without affecting the opening P2 of the neck P1 that is an insertion wound.
Since the wound after the electrode support 25 is collected can be made small, it is not necessary to sew or the like, and the wound can be closed by a technique such as compression hemostasis.

In the present embodiment, the nine protrusions 30 are arranged at different positions in the axis C direction in the natural state of the electrode support 25. However, the nine protrusions 30 are arranged in the recovery sheath 60 as electrodes. As long as the support 25 is inserted and reduced in diameter, the protrusions 30 may overlap in the axis C direction in the natural state of the electrode support 25 as long as the support 25 is disposed at different positions in the axis C direction.
For example, by providing the elastic members 26A, 26B, and 26C with high and low rigidity portions, the plurality of convex portions 30 are arranged at positions overlapping each other in the axis C direction in the natural state of the electrode support 25. When the electrode support 25 is inserted into the recovery sheath 60 and the diameter thereof is reduced, the elastic members 26A, 26B, and 26C are reduced in diameter non-uniformly so that the nine convex portions 30 are located at different positions in the axis C direction. It suffices if they are arranged.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. 16 to 18. However, the same parts as those of the above-described embodiment are denoted by the same reference numerals, the description thereof will be omitted, and only different points will be described. explain.
As shown in FIGS. 16 and 17, the electrical stimulation electrode 3 of the present embodiment includes three elastic member fixing portions 38 in the natural state of the electrode support 70 in addition to the components of the electrical stimulation electrode 1 of the first embodiment. Are arranged at different positions in the direction of the axis C. Here, the three elastic member fixing portions 38 are arranged at different positions in the axis C direction in the axis C direction except for one elastic member fixing portion 38 and the other elastic member fixing portions 38. This means that there is no portion overlapping the second elastic member fixing portion 38.
Amount of displacement in the axis C direction between the elastic member fixing portions 38 adjacent to each other in the axis C direction in the natural state of the electrode support 70 (the distance in the axis C direction between the center of the elastic member fixing portion 38 and the center of the elastic member fixing portion 38) ) Is desirably 2 mm or less. When the amount of deviation exceeds 2 mm, the adjustability of the direction of the electrode support 70 in the blood vessel (operability when rotating clockwise and counterclockwise with respect to the blood vessel axis) is deteriorated. There is a concern that the adjustment time increases. In other words, if the amount of deviation is 2 mm or less, the operator cannot determine the difference in operational feeling when rotating in both directions.

  As shown in FIG. 18, when the electrode support 70 is inserted into the recovery sheath 60 and the electrode support 70 is reduced in diameter, the three elastic member fixing portions 38 are arranged at different positions in the axis C direction. .

A treatment for placing the electrode support 70 of the electrical stimulation electrode 3 thus configured in the superior vena cava P5 will be described.
The lead part 20 is pulled back to the proximal end side with respect to the recovery sheath 60, and the electrode support 70 is accommodated in the sheath body 61 of the recovery sheath 60 to recover the electrode support 70.
If the three elastic member fixing portions 38 are overlapped in the direction of the axis C when the electrode support 70 is inserted into the recovery sheath 60 and the diameter of the electrode support 70 is reduced, the amount of drawing force stored in the recovery sheath 60 is large. Become. The elastic member fixing portion 38 is a point where two urging forces are generated among the elastic members 26A, 26B, and 26C, and requires a strong folding force (a force for pulling the electrode support 70 into the collection sheath 60). Is done.

On the other hand, in the electrical stimulation electrode 3 of the present embodiment, the three elastic member fixing portions 38 are arranged at different positions in the axis C direction when the diameter of the electrode support 70 is reduced. There is no overlap in the direction of the axis C, and the amount of pulling force stored in the recovery sheath 60 can be reduced.
The folding force at the time of extraction is dispersed in the direction of the axis C. As a result, when folded, the shape can be changed to the smallest narrow diameter. Therefore, the electrode support 70 can be completely stored in the recovery sheath 60, and the electrode support 70 can be safely removed outside the body without enlarging the wound.

For example, in the case of a lead anchor as shown in Patent Document 1 described above, the crossing position (crossing part) of the wire part is formed at a position (the same position) aligned in the blood vessel axis direction. It is presumed that the intersection position overlaps at the time of folding, and that the point interferes to prevent the shape from changing to a small diameter. In particular, when a lead anchor is formed by knitting a plurality of wire members, the influence becomes significant.
Although not specified in detail in Patent Document 1, it is considered necessary to remove (recover) in a folded form even when the device is removed from the blood vessel. In order not to spread the insertion wound into the blood vessel excessively, it is required to be folded down to the smallest diameter.

On the other hand, according to the electrical stimulation electrode 3 of the present embodiment, the outer diameter of the electrode support 70 can be further reduced when the electrode is recovered.
When the diameter of the electrode support 70 is reduced, the three elastic member fixing portions 38 are arranged at different positions in the direction of the axis C, so that the outer diameter of the electrode support 70 can be further reduced.

  In the present embodiment, the three elastic member fixing portions 38 are arranged at different positions in the axis C direction in the natural state of the electrode support 70, but the three elastic member fixing portions 38 are the recovery sheaths. If the electrode support 70 is inserted into the shaft 60 and reduced in diameter, the elastic member fixing portions 38 overlap in the axis C direction in the natural state of the electrode support 70. It may be.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. 19 to FIG. 21, but the same parts as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be omitted. explain.
As shown in FIGS. 19 and 20, the electrical stimulation electrode 4 of the present embodiment includes three overhang portions 40 and 41 in the natural state of the electrode support 75 in addition to the components of the electrical stimulation electrode 3 of the second embodiment. , 42 are arranged at different positions in the direction of the axis C. Center positions of the overhang portions 40, 41, and 42 in the direction of the axis C are indicated as positions 40a, 41a, and 42a.
The three elastic members 26A, 26B, and 26C have the same peripheral length. Since the circumference is the same, when the electrode support 75 is folded in the recovery sheath 60, the folding lengths of the elastic members 26A, 26B, and 26C are the same, and the folded shape is not an arc. The minimum diameter can be reduced to a substantially linear shape.

When the electrode support 75 of the electrical stimulation electrode 4 configured in this way is placed in the superior vena cava P5, the overhanging portions 40, 41, 42 are displaced in the longitudinal direction of the superior vena cava P5, and the inner wall of the superior vena cava P5 Abut securely. The biasing force of the elastic members 26A, 26B, and 26C can be applied to the inner wall of the superior vena cava P5, and the position of the electrode support 75 in the superior vena cava P5 can be stably maintained.
Further, as shown in FIG. 21, when the electrode support 75 is inserted into the recovery sheath 60, the positions of the centers of the three overhang portions 40, 41, and 42 do not overlap. That is, the positions 40a, 41a, 42a are shifted in the direction of the axis C. For this reason, the folding force (the force for pulling the electrode support body 75 into the recovery sheath 60) upon extraction is dispersed in the direction of the axis C.

As described above, according to the electrical stimulation electrode 4 of the present embodiment, the outer diameter of the electrode support 75 can be further reduced when it is collected.
Compared to the case where the centers of the three overhang portions 40, 41, 42 are formed at the same position in the axis C direction, the outer diameter of the electrode support 75 is reduced and the electrode support 75 is inserted into the recovery sheath 60. The amount of force required to do this can be reduced.

The first to third embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the configuration does not depart from the gist of the present invention. Changes, combinations, deletions, etc. are also included. Furthermore, it goes without saying that the configurations shown in the embodiments can be used in appropriate combinations.
For example, in the first to third embodiments, the convex portion 30 is formed so as to protrude from the outer surface of the elastic members 26A, 26B, and 26C over the entire circumference of the elastic members 26A, 26B, and 26C. The convex portion 30 only needs to be formed so as to protrude outward in the radial direction of the electrode support from the outer surface of the elastic members 26A, 26B, and 26C.

Although the nine protrusions 30 are formed on the electrode support, the number of the protrusions 30 formed on the electrode support is not limited to this and may be two or more. However, as the number of convex portions 30 formed on the electrode support is larger, the electrode support is more easily locked in the blood vessel, and the retention of the electrode support in the blood vessel is improved.
The number of elastic member fixing portions 38 formed on the electrode support is not limited to three, and may be two or four or more.

1, 3, 4 Electrical stimulation electrode (Medical electrical stimulation electrode)
10, 11 Stimulation electrode part 20 Lead part 25, 70, 75 Electrode support 26A, 26B, 26C Elastic member 30 Convex part 38 Elastic member fixing part (intersection part)
60 Recovery sheath C Axis P3 Right external jugular vein (blood vessel)
P5 superior vena cava (blood vessel)
P6 Vagus nerve (nerve)

Claims (4)

In order to stimulate nerves from the inner wall of a blood vessel, a medical electrical stimulation electrode used by being inserted into the blood vessel,
A stimulation electrode for applying electrical stimulation through the inner wall of the blood vessel;
A linear lead portion that passes through a wiring electrically connected to the stimulation electrode portion;
A linear elastic member is formed into a bowl shape that is substantially rotationally symmetric around a certain axis, and the stimulation electrode portion is provided in a part of the elastic member, and one end portion in the axial direction is an end of the lead portion. An electrode support connected to the section;
With
The electrode support is formed so as to protrude outward in the radial direction of the electrode support from the outer surface of the elastic member, and is arranged at a different position in the axial direction when the diameter of the electrode support is reduced. A medical electrical stimulation electrode comprising a plurality of convex portions. The electrode support has a plurality of intersecting portions to which the pair of elastic members intersect and are connected,
The plurality of intersecting portions are arranged at different positions in the axial direction when the electrode support has a reduced diameter,
The medical electrical stimulation electrode according to claim 1.   The medical electrical stimulation electrode according to claim 2, wherein the intersecting portion is formed by joining a pair of the elastic members to each other.   The medical electrical stimulation electrode according to claim 1, further comprising a recovery sheath through which the lead support is inserted and the reduced diameter electrode support is inserted.

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