JP6335025B2 - Medical stimulation electrode - Google Patents

Description

  The present invention relates to a medical electrical stimulation electrode.

2. Description of the Related Art Conventionally, stimulation generators that perform treatment by applying electrical stimulation to a living 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.
In some cases, these stimulation generators are used with an electrode lead (medical electrical stimulation electrode) embedded in a living body in order to bring an electrode lead for transmitting electrical stimulation into close contact with a stimulation target in the living body.
In general, an electrode lead applies electrical stimulation to biological tissue, or detects at least one electrode part for detecting electrical excitation generated in the biological tissue, and an electrical connector for electrically connecting to the stimulation generator; A lead body is provided between the electrode unit and the stimulus generator for transmitting electrical stimulation.
As an example of such an electrode lead, for example, in Patent Document 1, a conductive lead body having a proximal end configured to be connected to a pulse generator and a configuration in which an electric pulse is transmitted across a blood vessel wall are disclosed. There is described a nerve cell stimulation lead comprising a tip having at least one electrode and a lead anchor.
The lead anchor in this nerve cell stimulation lead is configured to expand from a folded shape to a previously formed expanded shape, and in the folded shape, the distal end portion is the effective length of the folded lead anchor. Have effective lengths that are substantially equal. The tip is coupled to the outside of the lead anchor, and when in the expanded shape, the lead anchor presses the tip of the lead against at least one blood vessel wall of the blood vessel in which the lead is expanded, and the lead tip is inside the blood vessel. Deploy and secure the department.
In addition, it is described that the tip of the lead is the same as the lead body or harder than the lead body, and that the lead anchor is made of a super elastic material wire.

Special table 2010-516405 gazette

However, the conventional medical electrical stimulation electrode as described above has the following problems.
The nerve cell stimulation lead described in Patent Document 1 expands a cage-shaped or basket-shaped lead anchor with the distal end portion of the lead having an electrode outside in the blood vessel, thereby connecting the electrode at the distal end portion of the lead to the blood vessel wall. To make contact.
However, while the lead anchor is a collection of wires made of superelastic material, the lead tip is soft or harder than the lead body, and the outer diameter is also larger than the wire. Obviously big. Therefore, the rigidity of the lead tip is different from the rigidity of the lead anchor.
Since the tip of the lead is pressed by the lead anchor from the opposite side of the electrode and is in contact with the blood vessel wall, if the pressing force does not always act in the appropriate direction according to the deformation of the lead anchor, the electrode is in a stable state It cannot contact the blood vessel wall.
In Patent Document 1, the wires are gathered at the distal end and proximal end of the lead anchor, expanded in diameter at the intermediate portion, and taken in a cage shape or basket shape that converges at both end portions, thereby moving outward in the radial direction. A pressing force is generated.
In such a configuration, a plurality of wires are arranged so as to cross the inside of the blood vessel at both the distal end and the proximal end of the lead anchor, and blood flow is easily inhibited.
For this reason, if the number of wires is increased or a thick wire is used to further stabilize the pressing force, there is a problem that the possibility of the thrombus being increased.

  The present invention has been made in view of the above-described problems, and provides a medical electrical stimulation electrode that is difficult to inhibit blood flow and can stably press a stimulation electrode portion against an inner wall of a blood vessel. With the goal.

In order to solve the above-mentioned problem, the medical electrical stimulation electrode according to the first aspect of the present invention is a medical electrical stimulation electrode for stimulating nerves from within a blood vessel, and applies electrical stimulation through the inner wall of the blood vessel. A combination of three or more linear elastic members disposed at an end of the lead electrode, a linear lead portion that passes through a wiring electrically connected to the stimulation electrode portion Thus, the outer diameter of the blood vessel is formed into an elastically deformable bowl shape that gradually expands from the end of the lead portion along the central axis thereof and then converges to a substantially constant outer diameter . An electrode support portion that presses the inner wall of the blood vessel by a pressing force that is larger than the inner diameter and elastically deformed radially inward with respect to the central axis in the blood vessel, and the elastic member is a single piece. In the natural state A pair of connecting end portions connected to the end portions of the lead portions, extending from each of the connecting end portions, formed in a substantially plane-symmetrical loop shape with respect to the first plane, and orthogonal to the first plane; A first linear portion facing the first plane, a convexly curved second linear portion projecting laterally of the second plane, and the second plane A bent portion that connects an end portion of the first linear portion and an end portion of the second linear portion, and the electrode support portion is rotated around the central axis in a natural state in an assembled state. And the second linear portion intersects with another adjacent second linear portion, so that the top of the second linear portion is the central axis. A closed loop shape that is stretchable about the central axis by the second linear portion. Opening is formed, the stimulation electrode portion of the electrode support portion, a periphery of the bent portion or the bent portion, and the contactable position to the inner wall of the vessel, with respect to the central axis It is set as the structure arrange | positioned toward the radial direction outer side .

  In the medical electrical stimulation electrode, it is preferable that the stimulation electrode portion is arranged such that a pair of electrodes is sandwiched between portions bent at one of the bent portions.

  In the medical electrical stimulation electrode, the bent portion includes a third linear portion projecting from an end portion of the first linear portion to a side opposite to a projecting direction of the second linear portion, A fourth linear portion projecting from the end of the second linear portion to the opposite side of the projecting direction of the second linear portion; the third linear portion; and the fourth linear portion. It is preferable that it is formed in the U-shape provided with the intermediate | middle linear part which connects.

  In the above-mentioned medical electrical stimulation electrode, the stimulation electrode part is arranged such that a pair of electrodes are arranged in each of the third linear part and the fourth linear part in one of the bent parts. It is preferable that

  In the medical electrical stimulation electrode, the elastic member is preferably fixed to the other elastic member and the intermediate linear portion.

  In the medical electrical stimulation electrode, the elastic member is preferably fixed to the other elastic member and at least a part of the first linear portion.

  In the medical electrical stimulation electrode, the elastic member is preferably fixed at a position where the second linear portion intersects with the other elastic member.

  The medical electrical stimulation electrode of the present invention is a closed loop in which three or more elastic members having a first linear portion and a second linear portion are arranged rotationally symmetrically and can be expanded and contracted by the second linear portion. Since the stimulation electrode part is arranged on the bowl-shaped electrode support part in which the shape of the opening is formed, the blood flow is hardly inhibited and the stimulation electrode part can be stably pressed against the inner wall of the blood vessel. Play.

It is a typical block diagram which shows the structure of the medical electrical stimulation electrode of the 1st Embodiment of this invention. It is a typical front view which shows the structure of the electrode support body part of the medical electrical stimulation electrode of the 1st Embodiment of this invention. It is a side view of A view in FIG. It is a typical perspective view which shows the structure of the elastic member of the medical electrical stimulation electrode of the 1st Embodiment of this invention. It is a top view of the B view in FIG. It is a side view of the C view in FIG. It is the typical top view which shows the structure of the stimulation electrode part of the medical electrical stimulation electrode of the 1st Embodiment of this invention, and its DD sectional drawing. It is the E view figure in FIG. 2, and its FF sectional drawing. It is a schematic diagram which shows the external appearance of a patient when the medical electrical stimulation electrode of the 1st Embodiment of this invention is detained in the patient's body. It is a schematic diagram which shows the state which indwelled the medical electrical stimulation electrode of the 1st Embodiment of this invention in the superior vena cava. It is the schematic diagram which shows the state of the deformation | transformation in the blood vessel of the electrode support body part of the medical electrical stimulation electrode of the 1st Embodiment of this invention, and the side view of the G view. It is the schematic diagram which shows a mode at the time of extracting the medical electrical stimulation electrode of the 1st Embodiment of this invention from a patient's body, and its U view and W view. It is a typical front view which shows the structure of the electrode support body part of the medical electrical stimulation electrode of the 2nd Embodiment of this invention. It is a side view of H view in FIG. It is the typical perspective view which shows the structure of the elastic member of the medical electrical stimulation electrode of the 2nd Embodiment of this invention, and its J view. It is a typical front view which shows the structure of the electrode support body part of the medical electrical stimulation electrode of the 3rd Embodiment of this invention. It is a side view of the K view in FIG. It is the typical perspective view which shows the structure of the elastic member of the medical electrical stimulation electrode of the 3rd Embodiment of this invention, the side view of the L view, and the M view in this side view. It is a typical front view which shows the structure of the electrode support body part of the medical electrical stimulation electrode of the 4th Embodiment of this invention. It is a side view of N view in FIG. It is the schematic diagram which shows the state of the deformation | transformation in the blood vessel of the electrode support body part of the medical electrical stimulation electrode of the 4th Embodiment of this invention, and the side view of the Q view. It is a typical front view which shows the structure of the electrode support body part of the medical electrical stimulation electrode of the 5th Embodiment of this invention. It is a side view of R view in FIG. It is a typical front view which shows the structure of the electrode support body part of the medical electrical stimulation electrode of the 6th Embodiment of this invention. It is a side view of S view in FIG. It is the schematic diagram which shows the state of the deformation | transformation in the blood vessel of the electrode support body part of the medical electrical stimulation electrode of the 6th Embodiment of this invention, and the side view of the T view.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.

[First Embodiment]
The medical electrical stimulation electrode according to the first embodiment of the present invention will be described.
FIG. 1 is a schematic configuration diagram showing the configuration of the medical electrical stimulation electrode according to the first embodiment of the present invention. FIG. 2 is a schematic front view showing the configuration of the electrode support portion of the medical electrical stimulation electrode according to the first embodiment of the present invention. FIG. 3 is a side view of FIG. FIG. 4 is a schematic perspective view showing the configuration of the elastic member of the medical electrical stimulation electrode according to the first embodiment of the present invention. FIG. 5 is a plan view as viewed from B in FIG. FIG. 6 is a side view as seen from C in FIG. FIG. 7A is a schematic plan view showing the configuration of the stimulation electrode portion of the medical electrical stimulation electrode according to the first embodiment of the present invention. FIG.7 (b) is DD sectional drawing in Fig.7 (a). FIG. 8A is an E view in FIG. FIG.8 (b) is FF sectional drawing in Fig.8 (a).

An electrical stimulation system 100 according to this embodiment shown in FIG. 1 is placed in a patient's blood vessel for a certain period of time and applies electrical stimulation to surrounding nerve tissue through the inner wall of the blood vessel. The electrical stimulation system 100 is suitable for performing nerve stimulation for a short period of time, unlike a system in which the entire system is implanted in the body and nerve stimulation is performed for a long period of time.
The electrical stimulation system 100 includes a medical electrical stimulation electrode 1 for stimulating a nerve from within a blood vessel, and an electrical stimulation device 8 that applies a stimulation pulse to the medical electrical stimulation electrode 1.

The medical electrical stimulation electrode 1 is inserted through stimulation electrodes 21 and 22 (stimulation electrode portions, electrodes) for applying electrical stimulation through the inner wall of the blood vessel and unillustrated wirings electrically connected to the stimulation electrodes 21 and 22. The linear lead part 3 to be provided, and the electrode support part 2 disposed at the tip part 3b (end part of the lead part) of the lead part 3 are provided.
The medical electrical stimulation electrode 1 is introduced into a patient's blood vessel in a state in which the lead portion 3 is inserted through the tubular guide sheath 7 and the electrode support portion 2 is folded and accommodated at the distal end of the guide sheath 7. Then, the electrode support 2 is pushed out of the guide sheath 7, and is placed in the patient's blood vessel.
In addition, in the electrical stimulation system 100, it is preferable that an antithrombotic coating is applied to a surface that comes into contact with blood on a member or a part inserted into a blood vessel of a patient in order to suppress thrombus generation.

For example, a tube made of polyurethane or polyamide can be used as the guide sheath 7.
As an example, the dimensions of the tubular portion of the guide sheath 7 in the present embodiment are an outer diameter of 2.8 mm, an inner diameter of 2 mm, and a length of 400 mm.
A branch portion 7b is provided at the proximal end portion of the guide sheath 7, and, for example, heparin that is an antithrombotic agent is passed through a duct formed inside the guide sheath 7 to the side portion of the branch portion 7b. A liquid supply tube 6 for continuously administering the chemical solution is connected.
An end portion of the branch portion 7b is provided with a seal portion 7a made of, for example, an O-ring to insert the lead portion 3 while maintaining the water tightness of the pipe line in the guide sheath 7.
At the end of the liquid feeding pipe 6 opposite to the branching portion 7b, a connector 6a comprising a liquid feeding means (not shown) such as a luer lock connector for connecting a syringe piston pump or the like is provided.

The lead part 3 is provided with a hard tip part 3b and a branch part 3c to which a liquid feeding pipe 5 is connected at both ends of a lead tube 3a, which is a flexible tubular member, and inside the lead tube 3a, A wiring portion 3d electrically connected to the stimulation electrodes 21 and 22 is inserted.
The wiring part 3d extends to the outside from the opening of the branch part 3c, and, for example, a connector 3e such as a known IS1 type is coupled to the end part for electrical connection with the electrical stimulation device 8. Yes.

The lead tube 3a is made of, for example, a resin tube having an outer diameter of 1 mm to 3 mm and a total length of about 500 mm, such as a polyurethane tube having excellent biocompatibility.
However, the outer diameter of the lead tube 3a is smaller than the inner diameter of the guide sheath 7, a gap is formed between the inner diameter surface of the guide sheath 7 and the lead sheath 3a can be fitted to the seal portion 7a of the guide sheath 7 so as to be able to advance and retract. And For example, when the inner diameter of the guide sheath 7 is 2.8 mm, about 2.5 mm is preferable.

The tip 3b is a tubular part to which the electrode support 2 is mounted. The tip 3b has an engagement hole 3f that engages a converging portion 27 of the electrode support 2, which will be described later, at the center of one end. It is connected to the lead tube 3a.
The outer diameter of the distal end portion 3b is substantially the same (including the same case) as the outer diameter of the lead tube 3a, and the step on the outer peripheral surface is 0 mm or more and 0.2 mm or less.
For this reason, the front-end | tip part 3b can be penetrated by the front-end | tip part (distal end side) of the guide sheath 7 so that advance / retreat is possible.
In the present embodiment, titanium is used as the material of the tip 3b. As the hole shape of the engagement hole 3f, a hexagonal hole is adopted corresponding to the outer shape of the converging portion 27 described later.

The lead portion 3 is inserted through the seal portion 7 a at the base end portion (proximal end side) of the guide sheath 7 so as to be able to advance and retract, and is exposed to the outside of the guide sheath 7.
The branch portion 3 c is provided at the proximal end portion of the lead portion 3 exposed to the outside of the guide sheath 7.
The liquid feeding tube 5 is for continuously administering a drug solution such as heparin, which is an antithrombotic agent, through a conduit (not shown) in the lead portion 3 and a discharge port (not shown) provided on the distal end side.
At the end of the liquid feeding pipe 5 opposite to the lead portion 3, a connector 5a comprising a liquid feeding means (not shown) such as a luer lock connector for connecting a syringe piston pump or the like is provided.

As shown in FIGS. 2 and 3, the electrode support portion 2 has a configuration in which linear elastic members 20 </ b> A, 20 </ b> B, and 20 </ b> C (linear elastic members) are combined and fixed by the converging portion 27 in this embodiment. .
The outer shape of the electrode support portion 2 is substantially constant after the diameter is gradually increased from the tip portion 3b of the lead portion 3 along the central axis O in the forward direction (distal end side, left side in FIG. 2). It is formed in the shape of an elastically deformable bowl that converges on the outer diameter.
The outer diameter of the electrode support 2 is larger than the inner diameter of the blood vessel so that the inner wall of the blood vessel can be pressed in the blood vessel in which the electrode support 2 is placed.

In the following description, when the relative position with respect to the electrode support 2 is described, the direction along the central axis O is the axial direction, the direction around the central axis O is the circumferential direction, and the central axis O is the plane perpendicular to the central axis O. The direction along the intersecting line is referred to as the radial direction.
In the axial direction, a side closer to the distal end portion 3b on the proximal end side may be referred to as a base end portion (side), and a side farther from the distal end portion 3b on the distal end side may be referred to as a distal end portion (side).
In the radial direction, a direction away from the central axis O may be referred to as a radial outer side (outer side), and a direction approaching the central axis O may be referred to as a radial inner side (inner side).

  The linear elastic members 20A, 20B, and 20C have the same shape except that the stimulation electrodes 21 and 22 are disposed only on the linear elastic member 20A.

In the following, unless otherwise specified, the shape of the linear elastic member 20A will be described, and the description of the linear elastic members 20B and 20C will be given the same reference numeral consisting of “numbers + lowercase letters” in the same shape. Description is omitted. Further, in order to distinguish which part of each of the linear elastic members 20A, 20B, and 20C indicates, subscripts A, B, and C are added following the lowercase letter of this code.
For example, the connecting end 20aB (20aC) in the linear elastic member 20B (20C) refers to a portion having the same shape corresponding to the connecting end 20aA in the linear elastic member 20A.
In addition, when there is no need to particularly distinguish the members and parts distinguished by the subscripts A, B, and C, the subscripts A, B, and C are omitted for simplification of the description in the specification. There is. However, in order to make it difficult to see in the drawing, only the reference numerals with subscripts A, B, and C are shown.
For example, “linear elastic member 20” and “connecting end portion 20a” respectively represent one of linear elastic members 20A, 20B, and 20C, and one of connecting end portions 20aA, 20aB, and 20aC. “Each linear elastic member 20” and “each connecting end 20a” represent all of the linear elastic members 20A, 20B, and 20C and all of the connecting end portions 20aA, 20aB, and 20aC, respectively.

The linear elastic member 20A is a member in which a three-dimensional loop shape is formed by bending one linear elastic member. Hereinafter, the linear elastic member 20A will be described with reference to FIGS. The shape of a single natural state will be described. Here, the natural state is, for example, a state where no external force other than gravity acts, and a state where the deformation of the linear elastic member 20A can be ignored.
As shown in FIG. 4, the linear elastic member 20A has a connecting end 20aA, a proximal end linear portion 20bA (first linear portion), and a distal end linear portion 20cA (from one end to the other end). 2nd linear part), proximal end side linear part 20dA (1st linear part), and connection end part 20eA are provided in this order.

The connecting end portions 20aA and 20eA are portions for fixing the linear elastic member 20A to the converging portion 27, which will be described later, and are engaged with the distal end portion 3b via the converging portion 27. It extends linearly along the axis O1, and is arranged in parallel and close to each other across the first axis O1.
The connecting end portions 20aA and 20eA are engaged with the distal end portion 3b via the converging portion 27 so that the first axis O1 is aligned with the central axis O of the distal end portion 3b.
The fixing method of the connecting end portions 20aA, 20eA and the converging portion 27 is not particularly limited, and for example, a fixing method such as adhesion, welding, or caulking can be appropriately selected according to the material of the converging portion 27.

As shown in FIG. 5, the base-end-side linear portions 20bA and 20dA include the first axis O1, and in the plane S2 (second plane) passing through the central axis of the connecting ends 20aA and 20eA, The parts are arranged symmetrically with each other and are U-shaped as a whole.
A third axis O3 passing through an end portion (hereinafter referred to as a distal end portion) that contacts the end portion of the distal end side linear portion 20cA in the proximal end linear portions 20bA and 20dA is in a positional relationship orthogonal to the first axis O1. .
That is, the base-side linear portions 20bA and 20dA are directed forward (left side in the drawing in FIG. 5) so as to be separated from the ends (base-end-side ends) connected to the connecting ends 20aA and 20eA, respectively. And are gradually separated from the first axis O1. And in the vicinity of the end part on the front end side, it is substantially parallel to the first axis O1 (including the parallel case).

The proximal-side linear portion 20bA (20dA) 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 first axis O1.
In this embodiment, as an example, the shape of the proximal side linear portion 20bA (20dA) is the distal end side region near the distal end side linear portion 20cA in the proximal end region b1 (d1) close to the connecting end portion 20aA (20eA). Compared to b2 (d2), a curve shape is employed in which the average rate of change in inclination with respect to the first axis O1 is greater.
The change in curvature at the boundary between the proximal end region b1 (d1) and the distal end side linear portion 20cA may be continuous or discontinuous.

The curvature and direction in the vicinity of the distal end portions of the proximal end linear portions 20bA and 20dA can be appropriately set in consideration of the deformation state in the blood vessel at the indwelling position and the pressing force on the inner wall of the blood vessel.
In the present embodiment, the proximal side linear portions 20bA and 20dA adopt a shape that is inclined so as to be separated from each other toward the distal end side portion. For this reason, the distal end side end portions of the base end side linear portions 20bA and 20dA are portions having the maximum width in the direction orthogonal to the first axis O1 of the linear elastic member 20A in the natural state.

As shown in FIG. 4, the distal-side linear portion 20cA has a convex shape that protrudes from the distal-side end portions of the proximal-side linear portions 20bA and 20dA toward the distal side toward the side of the plane S2. It is a curved part.
In the present embodiment, as an example, the tip-side linear portion 20cA is aligned on a plane S3 that includes the third axis O3 and intersects the plane S2 at an angle θ, and includes the first axis O1 and is orthogonal to the plane S2. It is formed in a C-shape that is plane-symmetric with respect to the plane S1 (first plane).
For this reason, the top portion 20gA of the distal end side linear portion 20cA 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 20cA 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 this embodiment, as shown in FIGS. 5 and 6, the shape of the distal-side linear portion 20 cA is, for example, the proximal-side line in the proximal-side region c1 (c3) close to the proximal-side linear portion 20 bA (20 dA). It extends in the shape of a curve or a line that inclines toward the plane S1 from the front end side end of the shape portion 20bA (20dA).
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 20gA 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 20gA is maximized and a bent portion is formed in the vicinity of the top portion 20gA is adopted.

As shown in FIGS. 4 and 5, in the vicinity of the connecting portion between the distal end side linear portion 20cA and the proximal end linear portion 20bA (20dA), a V-shaped bend having an intersection point with the third axis O3 as a bending point is provided. A portion 20fA (20hA) is formed.
With such a configuration, the linear elastic member 20A has a shape that is plane-symmetric with respect to the plane S1.

  In the present embodiment, as shown in FIG. 2, the stimulation electrode 21 is arranged at the end portion of the distal end side linear portion 20 c </ i> A in the bent portion 20 h </ i> A so as to face radially outward with respect to the central axis O. In addition, the stimulation electrode 22 is arranged at the end of the proximal side linear portion 20dA in the bent portion 20hA so as to face radially outward with respect to the central axis O.

Here, the internal structure of the linear elastic member 20A and the configuration of the stimulation electrodes 21 and 22 will be described.
As shown in FIGS. 7A and 7B, the linear elastic member 20 </ b> A is configured by a linear body in which the outer peripheral surface of the wire portion 23 is covered with an outer coating 26.

The wire portion 23 includes a wire main body 23a made of a metal wire and an inner covering 23b that covers and insulates the outer peripheral surface of the wire main body 23a.
The wire main body 23a is an appropriate metal wire having good elasticity that returns to a natural state when the external force is released without being plastically deformed by an external force received when the electrode support 2 is folded and accommodated in the guide sheath 7. Can be adopted. Examples of metal wires suitable for the wire body 23a include shape memory alloys and superelastic wires. The outer diameter of the wire body 23a is set to 0.1 mm to 0.4 mm, for example.
In this embodiment, the wire main body 23a employs, as an example, a super elastic wire having a diameter of 0.3 mm.

  As the inner coating 23b, an appropriate synthetic resin material that can be deformed together with the wire main body 23a and has electrical insulation, for example, polyurethane resin can be employed.

The outer covering 26 is a covering member that forms the outermost peripheral surface of the linear elastic member 20 </ b> A except for the exposed portions of the stimulation electrodes 21 and 22. Therefore, when the outer covering 26 is introduced into the blood vessel, the outer peripheral surface comes into contact with blood, a living tissue such as the inner wall of the blood vessel.
For this reason, the outer covering 26 is an insulating material that can be deformed together with the wire portion 23 and is formed of a material that is excellent in biocompatibility. The surface of the outer coating 26 is formed smoothly so as not to cause thrombus.
As a material suitable for the outer coating 26, for example, a polyurethane resin, a polyimide resin, or the like can be used.
The outer coating 26 is melt-bonded so as not to include an air layer with the wire portion 23 by heat fusion.
The inner coating 23b and the outer coating 26 are formed to have a thickness of, for example, 50 μm to 400 μm.

The stimulation electrodes 21 and 22 are different in arrangement position in the linear elastic member 20A, and both have the same configuration.
The stimulation electrode 21 (22) is formed of a biocompatible metal tube such as platinum iridium alloy, for example, and a part thereof is exposed to the outer periphery of the linear elastic member 20A through the opening 26a of the outer coating 26. The exposed portion is a cylindrical surface having a curvature along the outer peripheral surface of the outer coating 26, and is a shape seen from the direction along the third axis O3 of the exposed portion (viewed from the direction perpendicular to the paper surface of FIG. 7A). Is substantially rectangular.
In the present embodiment, as an example, a cylindrical tube member having a diameter of 0.8 mm and a length of 4 mm is adopted as the stimulation electrode 21 (22), and the shape of the exposed portion is a width of 0.5 mm and a length of 3.8 mm. It is said. Here, the longitudinal direction of the exposed portion coincides with the extending direction of the outer coating 26.
However, the exposed shape of the stimulation electrode 21 (22) is not limited to this, and for example, an elliptical shape or an elliptical shape that is long in the axial direction of the wire portion 23 is also possible.

A tubular insulating member 24 for preventing a short circuit with the wire portion 23 is inserted into the stimulation electrode 21 (22), and the wire portion 23 is inserted into the insulating member 24.
Moreover, the wiring 25 which comprises the wiring part 3d is electrically connected to the inner peripheral surface of the stimulation electrode 21 (22) buried in the outer coating 26.
As the wiring 25, for example, a stranded wire made of a nickel cobalt alloy (35NLT25% Ag material) having bending resistance is covered with an electrical insulating material (for example, ETFE (polytetrafluoroethylene) having a thickness of 20 μm). A thing can be used suitably.
The wiring 25 is disposed in the outer covering 26 and extends along the wire portion 23, and extends from the base end portions of the coupling end portions 20 aA and 20 eA to the lead portion 3 side.

As shown in FIG. 2, in the stimulation electrodes 21 and 22 having such a configuration, the longitudinal direction of each exposed portion is along the central axis of the distal-side linear portion 20cA and the proximal-side linear portion 20dA in the bent portion 20hA. , They are lined up in a non-parallel state that form obtuse angles with each other.
In order to efficiently apply electrical stimulation, it is important that the distance between the stimulation electrodes 21 and 22 is not too large. For this reason, it is preferable to arrange | position the stimulation electrodes 21 and 22 in the position where the shortest distance d of each exposed part becomes about 3 mm-8 mm in the natural state of the linear elastic member 20A.

As shown in FIG. 3, the linear elastic members 20A, 20B, and 20C having such a configuration are arranged such that each first axis O1 is aligned with the center axis O, and the top portions 20gA, 20gB, and 20gC are related to the center axis O. It arrange | positions so that it may space apart at equal intervals in the circumferential direction.
And as shown to Fig.8 (a), connection end part 20aA, 20eA, 20aB, 20eB, 20aC, 20eC is being fixed in the aggregated state bundled together by the convergence part 27. As shown in FIG.
For example, the converging portion 27 is formed in a hexagonal prism shape whose outer shape is formed in a hexagonal shape by inserting each connecting end portion 20a and each connecting end portion 20e into a tubular member made of titanium and then performing caulking. It is a member.
As shown in FIG. 8B, the converging portion 27 is inserted into a hexagonal engagement hole 3f formed coaxially with the central axis O at the distal end portion 3b and engaged in the circumferential direction. For example, it is fixed to the tip 3b. For this reason, the outer shape of the converging part 27 is formed in a hexagonal column shape that can be fitted into the engagement hole 3f.
Thus, the converging portion 27 and the tip portion 3b are in a relationship between the shaft portion having a hexagonal cross section and the hole portion, which are fitted to each other, and are engaged so as not to rotate around the central axis O. For this reason, when the lead part 3 is rotated around the central axis O, the electrode support part 2 is also rotated around the central axis O according to the rotation angle of the lead part 3.

Inside the distal end portion 3b, the wiring 25 extending from the connecting end portions 20aA and 20eA (not shown in FIG. 8B) extends through the interior of the distal end portion 3b and into the lead tube 3a. The wiring portion 3d is collected.
The position of the wiring portion 3d is fixed by a fixing portion 3g in the lead tube 3a, extends to the base end portion of the lead tube 3a, and extends to the outside from the branch portion 3c (see FIG. 1).

The electrode support portion 2 assembled in this way and fixed to the tip portion 3b has a three-dimensional rotationally symmetric three-dimensional shape with the central axis O as the rotational symmetry axis in the natural state.
For this reason, as shown in FIG. 3, when viewed from the direction along the central axis O, the base-side linear portions 20bA, 20dC, 20bB, 20dA, 20bC, and 20dB are arranged radially to divide the circumference into six equal parts. Yes.
Further, as shown in FIG. 2, when viewed from the direction intersecting the central axis O, each base-side linear portion 20 b and each base-side linear portion 20 d can be formed by rotating a U shape around the central axis O. It is arranged along a semi-spindle shape and has a bowl shape.

In addition, in such a natural state of the assembled state of the electrode support part 2, no external force other than gravity acts on the electrode support part 2. However, the linear elastic members 20 </ b> A, 20 </ b> B, and 20 </ b> C cross each other and are in contact with each other, and the specific linear elastic member 20 has a relationship of receiving external force from the other linear elastic members 20.
Therefore, in the natural state of the assembled state of the electrode support part 2, each linear elastic member 20 is deformed into a shape different from the shape of the single natural state. However, since the arrangement positions of the respective linear elastic members 20 are rotationally symmetrical three times with respect to the central axis O, the deformed shapes of the respective linear elastic members 20 are exactly the same. For this reason, the electrode support part 2 becomes a three-dimensional rotationally symmetric solid shape with respect to the central axis O in the assembled natural state.

As shown in FIG. 3, the distal end side linear portions 20cA, 20cB, and 20cC are arranged adjacent to each other in this order when viewed from the direction along the central axis O, and are adjacent to the other distal end side linear portions at the respective end portions. It overlaps the edge.
The top portions 20gA, 20gB, and 20C are aligned on a concentric circle with the central axis O as the center.

As shown in FIG. 2, when viewed from the direction intersecting with the central axis O, the distal end side linear portion 20cA intersects the distal end side linear portion 20cB so as to be radially inward from the distal end side linear portion 20cB. doing.
Similarly, the distal end side linear portion 20cB intersects the distal end side linear portion 20cC at a point X2 so as to be radially inward of the distal end side linear portion 20cC.
Similarly, the distal end side linear portion 20cC intersects the distal end side linear portion 20cA at a point X3 so as to be radially inward of the distal end side linear portion 20cA.
Therefore, when these tip end side linear portions 20cA, 20cB, and 20cC are viewed from the direction along the central axis O, the region between the points X1, X2, and X3, which are their intersections, as shown in FIG. A closed loop-shaped opening LP having a three-fold rotational symmetry close to a circular shape or a circular shape centering on O is formed.
The opening LP is the largest opening formed at the tip of the electrode support 2 in the natural state of the electrode support 2.

The electrical stimulation device 8 is a device portion that generates electrical stimulation between the pair of stimulation electrodes 21 and 22 based on the operation of the operator when the medical electrical stimulation electrode 1 is placed in a blood vessel. Although the detailed configuration of the electrical stimulation device 8 is not shown, it includes at least a power source that outputs a pulsed signal waveform and a control unit that generates a signal waveform and controls application timing.
As shown in FIG. 1, the electrical stimulation device 8 is electrically connected to the wiring portion 3 d in the lead portion 3 via a connector 3 e.
In this embodiment, the signal waveform output from the electrical stimulation device 8 is generated with a constant current system or a constant voltage system biphasic waveform group with a predetermined interval. The condition of the signal waveform can be appropriately set as necessary for electrical stimulation. Specifically, for example, it is possible to output a signal waveform such as generating a biphasic waveform with a frequency of 20 Hz and a pulse width of 50 μsec to 400 μsec from 3 to 20 sec per minute. .
At the time of outputting such a signal waveform, one of the stimulation electrodes 21 and 22 acts as a plus side electrode, and the other acts as a minus side electrode.

In order to perform electrical stimulation from within the blood vessel using such an electrical stimulation system 100, for example, the electrode support 2 of the medical electrical stimulation electrode 1 is introduced into the superior vena cava of the patient and the indwelling position is searched. Later, it is placed in the superior vena cava.
Moreover, when the necessary electrical stimulation is completed, the electrode support 2 is removed from the patient's body.
Below, the effect | action of the electrical stimulation system 100 is demonstrated centering on the effect | action in such indwelling and extraction.
FIG. 9 is a schematic view showing a state outside the patient's body when the medical electrical stimulation electrode according to the first embodiment of the present invention is placed in the patient's body. FIG. 10 is a schematic diagram showing a state in which the medical electrical stimulation electrode according to the first embodiment of the present invention is placed in the superior vena cava. Fig.11 (a) is a schematic diagram which shows the deformation | transformation state in the blood vessel of the electrode support body part of the medical electrical stimulation electrode of the 1st Embodiment of this invention. FIG.11 (b) is a side view of the G view in Fig.11 (a). FIGS. 12A and 12B are schematic views showing a state when the medical electrical stimulation electrode according to the first embodiment of the present invention is removed from the body of the patient. FIG. 12C is a U view in FIG. FIG. 12 (d) is a W view in FIG. 12 (b).

First, as shown in FIG. 9, the surgeon cuts the vicinity of the neck of the patient P to form an opening P1. A known introducer or dilator (not shown) is attached to the opening P 1, and the medical electrical stimulation electrode 1 accommodated in the guide sheath 7 is introduced together with the guide sheath 7. At this time, the position of the medical electrical stimulation electrode 1 (not shown in FIG. 9) is confirmed by confirming the positions of the wire part 23, the wiring 25, the electrode support part 2 (not shown in FIG. 9), etc. under X-rays. Install while confirming.
When the distal end of the guide sheath 7 reaches the vicinity of the indwelling position in the superior vena cava P3 (blood vessel) through the right external jugular vein P2 (blood vessel), the electrode support portion 2 of the medical electrical stimulation electrode 1 is guided to the guide sheath 7. Extrude outside. Then, the guide sheath 7 is pulled out to the proximal end side, and only the medical electrical stimulation electrode 1 is left in the blood vessel as shown in FIG.
The electrode support portion 2 pushed out into the superior vena cava P3 is expanded in diameter in the superior vena cava P3 in order to return to the natural shape by the elastic restoring force.
The outer diameter of the natural state of the electrode support unit 2, the size fry than the inner diameter of the superior vena cava P3, the electrode support portion 2 is pressed against the inner wall V1 of the superior vena cava P3.
As a result, the electrode support portion 2 has a smaller diameter than the natural state, and is elastically deformed by the reaction from the inner wall V1. The inner wall V <b> 1 is in close contact with the outer peripheral portion of the electrode support 2 while being deformed by receiving a pressing force from the electrode support 2.
For this reason, the electrode support part 2 is latched by the inner wall V1 of the superior vena cava P3 that is in contact by frictional force.

An example of the deformation state of the electrode support 2 at this time is shown in FIGS.
The electrode support portion 2 comes into contact with the inner wall V1 from the radially outermost portion, and as a result of receiving a reaction inward in the radial direction from these contact portions, the linear elastic members 20A, 20B, and 20C are deformed. .
Specifically, when each top portion 20g is pressed radially inward, each top bite bites into the inner wall V1, and each distal end side linear portion 20c is bent and deformed radially inward with each base end portion as a rotation center. Thereby, each front-end | tip side linear part 20c contact | abuts along the inner wall V1 entirely.
At this time, the points X1, X2, and X3, which are the respective intersections in the natural state, become points X1 ′, X2 ′, and X3 ′ that are shifted to the tip side of the electrode support 2 as shown in FIG. Moving. When viewed from the direction along the central axis O, the opening LP changes to an opening LP ′ substantially equal to the inner diameter of the inner wall V1, as shown in FIG.

  As described above, the positions of the intersections in the respective distal-side linear portions 20c of the electrode support body 2 change depending on the deformation state. However, by applying force at the intersecting portions, deformation of the respective distal-side linear portions 20c in the blood vessel. Has the effect of interlocking.

By such a deformation, each bending portion 20f and each bending portion 20h which are the proximal end side of each distal end side linear portion 20c have slightly larger bending angles, and adjacent distal end side linear portions 20c are adjacent in the circumferential direction. In the direction in which the bent portions 20f, 20h approach.
For example, as shown in FIG. 11A, the bent portions 20hC and 20fA adjacent to each other in the circumferential direction move in the circumferential direction such that the bent points are closer to each other.
For this reason, each base end side linear portion 20b and each base end side linear portion 20d are, for example, a distal end side region d2 of the proximal end side linear portion 20bA and a distal end side region b2 of the proximal end side linear portion 2dC. Compared with the state, it is in contact with the inner wall V2 in a state closer to the circumferential direction.

Thus, even if the electrode support 2 is deformed so as to be reduced in diameter in the superior vena cava P3, the deformed shape becomes a three-fold rotationally symmetric shape with the central axis O as the rotational symmetry axis. ing.
In the present embodiment, for example, the distal end portion of the distal-side linear portion 20cB, the bent portions 20hC and 20fA, the base portion 20B, passing through the apex portion 20gB of the proximal-side linear portion 20bB and extending along the axis parallel to the central axis O. The distal end portion of the end side linear portion 20bA and the distal end portion of the proximal end side linear portion 20dC gather. Thereby, the site | part where a pressing force becomes large concentrates on the area | region Y2.
Due to the deformation symmetry, as shown in FIG. 11B, regions where the pressing force is concentrated similarly occur in the regions Y1 and Y3 rotated by 120 ° from the region Y2.
That is, an equal pressing force acts radially outward from the electrode support portion 2 to the inner wall V1 from regions Y1, Y2, and Y3 formed at positions that divide the circumference into three equal parts around the central axis O. The tip 3b is held at the center of the superior vena cava P3.
Due to the symmetry of the deformation, the bending portion 20hA provided with the stimulation electrodes 21 and 22 is pressed with a stable pressing force radially outward to come into contact with the inner wall V1 and exposed from the outer coating 26. 21 and 22 adhere to inner wall V1.

Moreover, the electrode support part 2 of this embodiment has the external shape which follows a semi-spindle shape.
For this reason, compared with the shape that contacts the blood vessel only in the middle portion in the longitudinal direction, such as a shape along a circular shape or a spindle shape, there are more portions where the pressing force to the inner wall V1 is generated in the electrode support portion 2, and therefore the same When the same pressing range is pressed with the pressing force, the size can be further reduced.
In addition, since each linear elastic member 20 intersects each other to form a bowl shape, the external force received by one linear elastic member 20 is transmitted to the other linear elastic members 20 through the intersection position, The deformation state is interlocked, and the deformation amount is dispersed between the linear elastic members 20.
For this reason, even when a specific linear elastic member 20 receives an external force, the rotationally symmetrical shape of the semi-spindle shape is less likely to collapse. For example, when arc-shaped elastic members are spaced apart in the circumferential direction, In comparison, the inner wall V1 can be urged more stably.

In this way, as shown in FIG. 10, the electrode support 2 is roughly arranged in the superior vena cava P3. Adjacent to the superior vena cava P3 is a vagus nerve P6 (nerve) that is an example of a nerve to be stimulated.
Subsequently, as shown in FIG. 9, outside the body of the patient P, the electrical stimulation device 8 is filled in the connector 3e of the wiring portion 3d, and the dispenser 9 having the syringe piston pump filled with the drug solution in the connector 6a of the liquid feeding tube 6. Connect each one. In FIG. 9, a dispenser (not shown) is also connected to the connector 5a of the liquid supply pipe 5 (not shown).
Then, a well-known search operation for aligning the stimulation electrodes 21 and 22 with the electrical stimulation position is performed.
During the following operation, a chemical solution such as an antithrombotic agent is continuously supplied as appropriate through the liquid supply tubes 5 and 6 and is circulated in the blood vessel.

  In the search operation, while generating electrical stimulation from the electrical stimulation device 8, the medical electrical stimulation electrode 1 is operated from outside the body, and the position of the electrode support portion 2 is adjusted in the axial direction and the circumferential direction of the blood vessel. For example, if the heart rate obtained by an electrocardiograph (not shown) is monitored, the position where the most significant decrease in heart rate is confirmed is the position where the stimulation electrodes 21 and 22 face the vagus nerve. Can be easily found.

In such a search operation, since the electrode support 2 presses the inner wall V1 evenly in three axially symmetric directions, the stimulation electrodes 21 and 22 are also urged by the inner wall V1. It is securely in contact with V1. For this reason, leakage of electrical energy from the stimulation electrodes 21 and 22 to the blood side is suppressed.
When the positioning of the electrical stimulation position is completed and the indwelling position is determined, a biphasic signal for applying electrical stimulation is applied by the electrical stimulation device 8 at an appropriate timing, and electrical stimulation of the vagus nerve P6 is performed. Thereby, effects such as suppressing the heart rate of the patient P within an appropriate range can be obtained.

In this indwelling state, the electrode support portion 2 has the opening portion LP ′ on the distal end side formed along the inner wall V1, and the portions of the respective distal end side linear portions 20c constituting the opening portion LP ′ are substantially in contact with the inner wall V1. It touches. For this reason, blood flow is not hindered at the tip of the electrode support 2.
Further, the distal end portion 3b is held at the central portion of the inner wall V1, and in the radial direction, the proximal end side linear portions 20b and the proximal end side linear portions 20d that are smaller in diameter than the distal end portion 3b are arranged radially, Since they are separated from each other in the circumferential direction, blood flows smoothly.
For this reason, compared with the prior art in which the elastic wire is assembled and fixed at both the distal end portion and the proximal end portion, the blood flow is more reliably generated by the amount of the opening LP ′ formed on the distal end side. It is hard to be disturbed. Thereby, in the indwelling state of the electrode support part 2, it can prevent more reliably that a thrombus generate | occur | produces.

When electrical stimulation is continuously applied to the vagus nerve P6 by the electrical stimulation device 8 for a necessary period, the medical electrical stimulation electrode 1 is removed from the patient P by pulling it out in the direction opposite to the inserted path. At this time, since the electrode support part 2 is a shape along the semi-spindle shape whose outer peripheral part is reduced in diameter toward the tip part 3b, it can be pulled out smoothly.
At that time, as shown in FIG. 10, the inner diameter of the blood vessel decreases in the order of the inner wall V1 in the superior vena cava P3, the inner wall V2 near the subclavian vein, and the inner wall V3 of the right external jugular vein P2.
For this reason, for example, as shown in FIGS. 12A and 12B, when the inner walls V2 and V3 are reached, the diameter reduction proceeds in accordance with the change in the respective inner diameters.
At this time, the electrode support 2 is deformed so as to reduce the diameter uniformly while maintaining a three-fold rotationally symmetric shape. For example, when reaching the inner wall V2, as shown in FIG. 12 (c), the diameter is smaller than that of the inner wall V1, but the opening LP ″ opens in a circle substantially along the inner wall V2. .

However, when moving to the right external jugular vein P2, as shown in FIG. 12D, the inner diameter of the inner wall V3 is reduced to about 程度 of the inner diameter of the superior vena cava P3. It is bent along the axial direction of the blood vessel. For this reason, each top 20g is separated from the inner wall V3, and when viewed from the central axis O, the shape of the opening LP ′ ″ becomes a triangular shape inscribed in the inner wall V3. As a result, the deformed tip end portion of the electrode support portion 2 has a structure in which the tip portion is not only reduced in diameter, but also the top portions 20g are close to the inner side in the radial direction, and the tip is narrowed.
That is, the area of the opening LP ′ ″ is narrower than the inner diameter of the blood vessel or the outer shape of the electrode support 2 on the proximal end side, and the distal end has a bowl-like shape close to a closed state. For this reason, even if a thrombus is formed and peeled off in the electrode support part 2, it is easily taken into the electrode support part 2 and discharged to the outside together with the electrode support part 2.
Further, as the diameter is reduced in this way, each linear elastic member 20 of the electrode support portion 2 extends linearly along the central axis O, so that the resistance in the pulling direction is reduced.

In this way, the medical electrical stimulation electrode 1 of the present embodiment is placed in the blood vessel of the patient P and can be removed from the patient P after performing appropriate electrical stimulation.
The medical electrical stimulation electrode 1 includes linear elastic members 20A, 20B, and 20C having proximal end side linear portions 20b and 20d and a distal end side linear portion 20c, which are arranged rotationally symmetrically, and are expanded and contracted by the distal end side linear portions 20c. Stimulation electrodes 21 and 22 are arranged on a bowl-shaped electrode support 2 having a possible opening LP. For this reason, it is hard to inhibit blood flow, and the stimulation electrodes 21 and 22 can be stably pressed against the inner wall of the blood vessel.

[Second Embodiment]
Next, a medical electrical stimulation electrode according to a second embodiment of the present invention will be described.
FIG. 13: is a typical front view which shows the structure of the electrode support body part of the medical electrical stimulation electrode of the 2nd Embodiment of this invention. FIG. 14 is a side view as viewed in H in FIG. Fig.15 (a) is a typical perspective view which shows the structure of the elastic member of the medical electrical stimulation electrode of the 2nd Embodiment of this invention. FIGS. 15B and 15C are J views in FIG.

The medical electrical stimulation electrode 31 of this embodiment, which shows the shape in the natural state in FIGS. 13 and 14, is for stimulating nerves from within the blood vessel, and is used for the medical electrical stimulation system 100 of the first embodiment. It can be used instead of the stimulation electrode 1.
The medical electrical stimulation electrode 31 includes an electrode support 32 instead of the electrode support 2 of the first embodiment.
Hereinafter, a description will be given centering on differences from the first embodiment.

The electrode support 32 is replaced with linear elastic members 33A, 33B, and 33C (linear elastic members) instead of the linear elastic members 20A, 20B, and 20C of the electrode support 2 of the first embodiment. Prepare.
Here, the linear elastic members 33 </ b> A, 33 </ b> B, and 33 </ b> C have the same shape except that the linear elastic member 33 </ b> A includes the stimulation electrodes 21 and 22. Therefore, in the following, with respect to the electrode support portion 32, as in the first embodiment, the same shape members and parts are denoted by the reference numerals “numbers + lowercase letters”, and the description thereof is omitted as appropriate. When it is necessary to distinguish, suffixes A, B, and C are added. The rules for abbreviations of subscripts A, B, and C are the same as those in the first embodiment.

  As shown in FIG. 15A, the linear elastic member 33A (33B, 33C) is a bent portion 20hA of the linear elastic member 20A (20B, 20C) in the first embodiment. Instead of (20hB, 20hC), a bent portion 33hA (33hB, 33hC) is provided.

As shown in FIG. 15 (b), the bent portion 33hA has a distal end with respect to the plane S2 between the distal end portion of the proximal end side linear portion 20dA and the proximal end portion of the proximal end side region c3 of the distal end side linear portion 20cA. It is a site | part formed in the U-shape which protrudes on the opposite side to the side linear part 20cA.
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 formed by a curved line, or a shape (a U-shape) formed by one straight portion bent at the end of two straight portions as in the present embodiment. ).
The bent portion 33hA of the present embodiment includes a first portion h1 (third linear portion), a second portion h2 (intermediate linear portion), and a third portion h3 (fourth linear portion).

The first portion h1 is a linear portion that is bent at the distal end portion of the proximal end linear portion 20dA. 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 22, and is preferably 4.5 mm to 7.0 mm, for example.

The second portion h2 is a bent linear portion at the end of the first portion h1 in the protruding direction, and is located on the extension line of the proximal side linear portion 20dA when viewed from the normal direction of the plane S2. It extends parallel to 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 end portion on the proximal end side region c3 side of the distal end side linear portion 20cA. 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 °.
The connection portion with the distal-end-side linear portion 20cA may be bent, or may be configured not to be bent depending on the magnitude of the angle θ.

The stimulation electrode 21 is disposed at an intermediate portion of the first portion h1 so that the longitudinal direction thereof is along the central axis direction of the first portion h1, and a part thereof is exposed on the surface that is radially outward with respect to the first axis O1. It is provided to do.
The stimulation electrode 22 is disposed at an intermediate portion of the third portion h3 so that its longitudinal direction is along the central axis direction of the third portion h3, and a part thereof is exposed on the surface that is radially outward with respect to the first axis O1. It is provided to do.

  Further, the positions of the first portion h1 and the second portion h2 of the stimulation electrodes 21 and 22 in the axial direction are not particularly limited as long as electrical stimulation can be applied to stimulation-symmetric nerve tissue. However, when it is parallel to a blood vessel like the vagus nerve P6, it is preferable to arrange it so as to face the axial direction of the electrode support 32.

  Moreover, the preferable range of the distance between the stimulation electrodes 21 and 22 is the same as that in the first embodiment. For this reason, the length of the 2nd part h2 is set to the length used as the preferable range of the distance between the stimulation electrodes 21 and 22. FIG.

  As shown in FIG. 15C, the bent portion 33hB (33C) of the linear elastic member 33B (33C) is obtained by removing the stimulation electrodes 21 and 22 from the bent portion 33hA.

With such a configuration, each linear elastic member 33 has a plane-symmetric shape with respect to the plane S1 except for the asymmetry of the bent portion 33h and the portion opposed to the bent portion 33h in the radial direction. That is, the linear elastic member 33 is not nearly plane-symmetric with respect to the plane S1, but has a shape close to plane symmetry as a whole.
In the present specification, a shape that is plane-symmetric and a shape that is not only plane-symmetric but is nearly plane-symmetric as a whole are referred to as “substantially plane-symmetric”.

In the electrode support portion 32 having such a configuration, each linear elastic member 33 includes a bent portion 33h. In the linear elastic member 33A, only the stimulation electrodes 21 and 22 are provided on the bent portion 33hA. It differs from the electrode support part 2 of the said 1st Embodiment.
For this reason, the medical electrical stimulation electrode 31 includes linear elastic members 33A, 33B, 33C each having a proximal end side linear portion 20b, 20d and a distal end side linear portion 20c in a rotationally symmetrical manner, and each distal end side linear portion. Stimulation electrodes 21 and 22 are arranged on a bowl-shaped electrode support body 32 in which an opening LP that can be expanded and contracted by 20c is formed. For this reason, similarly to the first embodiment, the blood flow is hardly inhibited, and the stimulation electrodes 21 and 22 can be stably pressed against the inner wall of the blood vessel.

Further, in particular, each linear elastic member 33 is provided with a U-shaped bent portion 33h projecting in the circumferential direction at a position facing each bent portion 20f in a substantially radial direction. The inner wall is pressed.
As described above, by having the bent portion 33h, the line length of the portion where the pressing force to the blood vessel is increased is increased as compared with the first embodiment, so that the contact area with the blood vessel is increased and the region is more stable. It can be pressed and locked.
Further, in the vicinity of the bent portion 33h, more stable pressing is possible in that the pressing force is likely to be concentrated on a small piece-like region having a U-shaped outer shape of the bent portion 33h.

Moreover, since the stimulation electrodes 21 and 22 are provided in the bending part 33hA which has four bending points, the axial distance in the electrode support part 32 is prescribed | regulated by the length of the 2nd part h2. . For this reason, compared with the case where it is provided in the bending part 20hA which has only one bending point like the said 1st Embodiment, the change of the distance between the stimulation electrodes 21 and 22 and a relative position becomes fewer. .
For this reason, even if the electrode support part 32 is deformed by the movement of the search operation or the body movement at the time of applying the stimulus, the relative positions of the stimulation electrodes 21 and 22 are stabilized, and stable electrical stimulation is easily generated.

Moreover, in this embodiment, the longitudinal direction of the stimulation electrodes 21 and 22 intersects the axial direction of the electrode support part 32, and is arranged along the substantially circumferential direction. For this reason, when the electrode support part 32 is detained in the superior vena cava P3, the stimulation electrodes 21 and 22 easily cross the vagus nerve P6 and are easily arranged at the stimulation position.
In particular, if the stimulation electrodes 21 and 22 are arranged in a positional relationship facing each other along the axial direction of the electrode support 32, the width of both of the stimulation electrodes 21 and 22 across the vagus nerve P6 becomes wide, and the electrode support This is more preferable because the degree of freedom in arrangement of the portion 32 with respect to the circumferential rotation increases. In this case, it becomes easier to arrange the stimulation electrodes 21 and 22 at the stimulation position. Further, the margin of positional deviation in the circumferential direction of the electrode support 32 is increased, and more stable electrical stimulation can be performed.

[Third Embodiment]
Next, a medical electrical stimulation electrode according to a third embodiment of the present invention will be described.
FIG. 16: is a typical front view which shows the structure of the electrode support body part of the medical electrical stimulation electrode of the 3rd Embodiment of this invention. FIG. 17 is a side view of FIG. FIG. 18A is a schematic perspective view showing the configuration of the elastic member of the medical electrical stimulation electrode according to the third embodiment of the present invention. FIG. 18B is a side view of the view L in FIG. FIG. 18C is an M view in FIG.

The medical electrical stimulation electrode 41 of the present embodiment, which is shown in FIGS. 16 and 17 in its natural state, is for stimulating nerves from within a blood vessel. The medical electrical stimulation system 100 of the electrical stimulation system 100 of the first embodiment is used. It can be used instead of the stimulation electrode 1.
The medical electrical stimulation electrode 41 includes an electrode support 42 instead of the electrode support 32 of the second embodiment.
Hereinafter, the points different from the first and second embodiments will be mainly described.

The electrode support 42 replaces the linear elastic members 33A, 33B, and 33C of the electrode support 32 of the second embodiment with linear elastic members 43A, 43B, and 43C (linear elastic members). Prepare.
Here, the linear elastic members 43A, 43B, and 43C have the same shape except that the linear elastic member 43A includes the stimulation electrodes 21 and 22. For this reason, in the following, with respect to the electrode support portion 42, as in the first embodiment, the same shape members and parts are denoted by the reference numerals "numbers + small letters", and the description thereof is omitted as appropriate. When it is necessary to distinguish, suffixes A, B, and C are added. The rules for abbreviations of subscripts A, B, and C are the same as those in the first embodiment.

  The linear elastic member 43A (43B, 43C) is a bent portion 20fA of the linear elastic member 33A (33B, 33C) in the second embodiment, as shown in FIG. Instead of (20fB, 20fC), a bent portion 43fA (43hB, 43hC) is provided.

As shown in FIG. 18C, the bent portion 43fA has a distal end with respect to the plane S2 between the distal end portion of the proximal side linear portion 20bA and the proximal end portion of the proximal end side region c1 of the distal end side linear portion 20cA. It is a site | part formed in the U-shape which protrudes on the opposite side to the side linear part 20cA.
The bent portion 43fA of the present embodiment includes a first portion f1 (third linear portion), a second portion f2 (intermediate linear portion), and a third portion f3 (fourth linear portion).
The outer shape of the bent portion 43fA may be different from the bent portion 33hA provided at a position facing the radial direction, but in the present embodiment, a shape symmetrical to the bent portion 33hA is adopted with respect to the plane S1. .
For this reason, the outer shape of each linear elastic member 43 of this embodiment has a shape that is plane-symmetric with respect to the plane S1, and the first portion f1, the second portion f2, and the third portion f3 are respectively The bent portion 33hA has the same outer shape as the first portion h1, the second portion h2, and the third portion h3.
However, unlike the bent portion 33hA, the bent portion 43fA is not provided with the stimulation electrodes 21 and 22.

The electrode support portion 42 having such a configuration is similar to a portion in which each linear elastic member 43 faces substantially in the radial direction across the plane S1 with respect to each bent portion 33h in the second embodiment. Only the point provided with the bent part 43f of a shape differs from the electrode support part 32 of the said 2nd Embodiment.
For this reason, the medical electrical stimulation electrode 41 includes linear elastic members 43A, 43B, and 43C each having the proximal end side linear portions 20b and 20d and the distal end side linear portion 20c in a rotationally symmetrical manner, and each distal end side linear portion. Stimulation electrodes 21 and 22 are arranged on a bowl-shaped electrode support 42 having an opening LP that can be expanded and contracted by 20c. For this reason, similarly to the first and second embodiments, the blood flow is hardly inhibited, and the stimulation electrodes 21 and 22 can be stably pressed against the inner wall of the blood vessel.

Further, in particular, each linear elastic member 43 is provided with a U-shaped bent portion 43f projecting in the circumferential direction at a position facing the respective bent portion 33h and the substantially radial direction across the plane S1. As a result, the inner wall of the blood vessel is pressed.
For this reason, since the same action as the bending part 33h is acquired by the bending part 43f also on the radial direction opposite side of the bending part 33h, more stable pressing is possible.

[Fourth Embodiment]
Next, a medical electrical stimulation electrode according to a fourth embodiment of the present invention will be described.
FIG. 19 is a schematic front view showing the configuration of the electrode support portion of the medical electrical stimulation electrode according to the fourth embodiment of the present invention. 20 is a side view of the N view in FIG. FIG. 21A is a schematic diagram showing a state of deformation in the blood vessel of the electrode support portion of the medical electrical stimulation electrode according to the fourth embodiment of the present invention. FIG. 21B is a side view as viewed from Q in FIG.

19 and 20, the medical electrical stimulation electrode 51 of the present embodiment whose shape is in a natural state is for stimulating nerves from within a blood vessel. The medical electrical stimulation system 100 of the electrical stimulation system 100 of the first embodiment is used. It can be used instead of the stimulation electrode 1.
The medical electrical stimulation electrode 51 includes an electrode support 52 in place of the electrode support 42 in the third embodiment.
The following description will focus on differences from the first and third embodiments.

In the linear elastic members 43A, 43B, and 43C of the electrode support 42 in the third embodiment, the electrode support 52 includes a bent portion 33h and a bent portion 43f of another linear elastic member 43. Only the points fixed in the two portions h2 and f2 are different.
That is, the second portion h2 of the bent portion 33hA and the second portion f2 of the bent portion 43fB are fixed by the elastic member fixing portion 54, and the second portion h2 of the bent portion 33hB and the second portion f2 of the bent portion 43fC. Are fixed by the elastic member fixing portion 54, and the second portion h2 of the bent portion 33hC and the second portion f2 of the bent portion 43fA are fixed by the elastic member fixing portion 54.

Each elastic member fixing portion 54 can be formed by fusing and welding the outer coverings 26 of the respective linear elastic members 43 or bonding them with an adhesive or the like.
In addition, each elastic member fixing | fixed part 54 may be provided over the full length of each 2nd part h2 and f2, and may be provided in the some dot form spaced apart in the longitudinal direction.

The electrode support portion 52 having such a configuration is such that the bent portions 33h and 43f are fixed by the elastic member fixing portions 54, so that an H-shaped pressing force is applied to the outermost periphery in a natural state when viewed from the radially outer side. A portion 55 is formed.
For example, as shown in FIG. 19, the pressing portion 55 formed by the bent portion 33hA and the bent portion 43fB is elastically supported by the two linear portions of the proximal-side linear portions 20dA and 20bB on the proximal end side. On the distal end side, the distal end side linear portions 20cA and 20cB are connected to the two linear portions.
As shown in FIG. 20, the opening portion LP in the natural state is formed on the radially inner side than each pressing portion 55.

As shown in FIGS. 21A and 21B, when the electrode support 52 is inserted into the superior vena cava P3, first, each pressing portion 55 comes into contact with the inner wall V1 and is pressed radially inward. As a result, the circumferential distance of the pressing portion 55 to which the end portion of each tip-side linear portion 20c is connected is narrowed, so that deformation that bends at the portion of each top portion 20g occurs. Thereby, each top part 20g moves to radial direction outer side, and contact | abuts to the inner wall V1, and each top part 20g also presses the inner wall V1.
For example, the pressing portion 55 formed by the bent portion 33hA and the bent portion 43fB and the tip-side linear portion 20cB in the vicinity of the top portion 20gC are substantially in the same position in the circumferential direction of the electrode support portion 52, and are axially In contact with the inner wall V1 at a position separated from each other. In other parts, it is deformed into a three-fold rotational symmetry.
For this reason, unlike the natural state, the opening LP ′ is formed in a region substantially aligned with the inner wall V1.

Here, the pressing force acting on each pressing portion 55 will be considered.
In the electrode support 52 in the deformed state as described above, the pressing portions 55 of the two linear elastic members 20 fixed by the elastic member fixing portion 54 and the top portions 20g of the other linear elastic members 20 are: Three sets of two main abutting portions separated in the axial direction are formed 120 ° apart in the circumferential direction. As a result, the inner wall V1 is pressed evenly in three directions.

For example, the pressing portion 55 formed by the bent portion 33hA and the bent portion 43fB extends to the proximal end side, and is elastically supported by the two linear portions of the proximal end linear portions 20bA and 20dB connected to the distal end portion 3b. Has been. Further, the pressing portion 55 is elastically supported by the two linear portions of the distal end side linear portions 20cA and 20cB extending to the distal end side being brought into contact with the inner wall V1 at the top portions 20gA and 20gB, respectively.
As described above, the pressing portion 55 is located at an intermediate portion between the two curved linear portions supported by the inner wall V1 opposite to the abutting inner wall V1 and the tip portion 3b, and such a pair of lines The inner wall V1 is pressed by the elastic restoring force of the shaped portion.

Therefore, unlike the third embodiment, each of the bent portions 33h and 43f is pressed by the elastic restoring force of one curved linear portion, and the elastic restoring force of the pair of linear portions. It is pressed by. In other words, in the third embodiment, the pressing force is distributed at six locations in the circumferential direction, whereas in this embodiment, the pressing force is more strongly pressed because it is concentrated at three locations in the circumferential direction. be able to.
Thereby, the stimulation electrodes 21 and 22 can be more reliably and stably pressed against the inner wall V1.

  Moreover, since each pressing part 55 consists of the bending parts 33h and 43f, compared with the case where it presses only the bending part 33h and the bending part 43f independently like the said 3rd Embodiment, the press which makes | forms an H shape. The pressing range of the portion 55 is wide, and the contact length with the inner wall V1 per place is also increased. Also in this respect, the pressing can be performed more stably, and the fixing position can be stabilized.

As described above, according to the electrode support portion 52, the bent portions 33h and 43f are fixed by the elastic member fixing portion 54 to form the pressing portion 55, and the stimulation electrodes 21 and 22 are provided in one of the pressing portions 55. Only the difference is from the electrode support 42 of the third embodiment.
For this reason, the medical electrical stimulation electrode 51 is unlikely to inhibit the blood flow, and can stably press the stimulation electrodes 21 and 22 against the inner wall of the blood vessel, as in the third embodiment.
In particular, since the pressing portion 55 is formed, the main pressing portions are formed at three locations that divide the inner wall of the blood vessel into three parts in the circumferential direction when inserted into the blood vessel, so that more stable pressing can be achieved. It becomes possible. For this reason, the indwelling position can be made more stable, and more stable electrical stimulation can be performed.

[Fifth Embodiment]
Next, a medical electrical stimulation electrode according to a fifth embodiment of the present invention will be described.
FIG. 22 is a schematic front view showing the configuration of the electrode support portion of the medical electrical stimulation electrode according to the fifth embodiment of the present invention. FIG. 23 is a side view of the view R in FIG.

The medical electrical stimulation electrode 61 of the present embodiment, which is shown in FIGS. 22 and 23 in a natural state, is for stimulating nerves from within a blood vessel. The medical electrical stimulation system 100 of the first embodiment has the medical electrical stimulation system 100 of FIG. It can be used instead of the stimulation electrode 1.
The medical electrical stimulation electrode 61 includes an electrode support portion 62 instead of the electrode support portion 42 of the third embodiment.
The following description will focus on differences from the first and third embodiments.

The electrode support portion 62 is a base end side linear portion 20b of the linear elastic member 43A of the electrode support portion 42 of the third embodiment, 43B, 43C, and the base end side linear shape of the other linear elastic member 43. The only difference is that the portion 20d is fixed on the base end side.
That is, the base end side linear portions 20dA, 20bC, the base end side linear portions 20bA, 20dB, and the base end side portions of the base end side linear portions 20dC, 20bB are fixed by the elastic member fixing portion 64.
The position and length of the elastic member fixing portion 64 can be appropriately set in consideration of the balance of the pressing force during deformation.
In the present embodiment, as an example, the range from the distal end portion 3b side to 2/3 is fixed in each proximal end side linear portion 20b, 20d.
Each elastic member fixing portion 64 can be formed by fusing and welding the outer coverings 26 of the respective linear elastic members 43 or bonding them with an adhesive or the like.
The elastic member fixing portion 64 may be provided without being interrupted in the longitudinal direction of the proximal end side linear portions 20b and 20d, but may be provided in a plurality of points separated in the longitudinal direction.

  The electrode support portion 62 having such a configuration fixes the proximal end side linear portion 20b and the proximal end side linear portion 20d of the other linear elastic member 43 on the proximal end side. For this reason, since the integrity of the bent portions 33h and 43f connected to the proximal side linear portions 20b and 20d fixed to each other is increased as compared with the third embodiment, the pressing force is further improved. In addition, since the bent portions 33h and 43f are close to being fixed to each other, an operation close to the operation of the fourth embodiment can be obtained.

Further, as shown in FIG. 23, when viewed from the direction along the central axis O, two proximal ends of the proximal end linear portions 20b and 20d extending radially outward from the distal end portion 3b are bundled two by two. Three sets of linear portions extend radially.
For this reason, since the circumferential gap between the linear portions is widened, blood flow is less likely to be inhibited.

  Thus, according to the medical electrical stimulation electrode 61, since the electrode support 62 is provided, the blood flow is hardly inhibited and the stimulation electrodes 21 and 22 are placed on the inner wall of the blood vessel as in the third embodiment. It can be pressed stably.

[Sixth Embodiment]
Next, a medical electrical stimulation electrode according to a sixth embodiment of the present invention will be described.
FIG. 24 is a schematic front view showing the configuration of the electrode support portion of the medical electrical stimulation electrode according to the sixth embodiment of the present invention. FIG. 25 is a side view of the S view in FIG. FIG. 26A is a schematic diagram showing a state of deformation in the blood vessel of the electrode support portion of the medical electrical stimulation electrode according to the sixth embodiment of the present invention. FIG. 26B is a side view of the T view in FIG.

The medical electrical stimulation electrode 71 of the present embodiment whose natural state is shown in FIGS. 24 and 25 is for stimulating nerves from inside the blood vessel, and is used for the medical electrical stimulation system 100 of the first embodiment. It can be used instead of the stimulation electrode 1.
The medical electrical stimulation electrode 71 includes an electrode support 72 instead of the electrode support 62 of the fifth embodiment.
The following description will focus on differences from the first and fifth embodiments.

The electrode support portion 72 is only provided with an elastic member fixing portion 74 that fixes the tip-side linear portions 20c that intersect each other at the points X1, X2, and X3 of the electrode support portion 62 of the fifth embodiment. Different.
For this reason, as shown in FIG. 23, an opening portion LP composed of the distal end side portions of the distal end side linear portions 20cA, 20cB, and 20cC is formed on the distal end side of each elastic member fixing portion 74.
Each elastic member fixing portion 74 can be formed by fusing and welding the outer coverings 26 of the respective linear elastic members 43 or bonding them with an adhesive or the like.

Due to the symmetry of the electrode support 72, the elastic member fixing portions 74 and 64 are aligned one by one on a plane that includes the central axis O and intersects with each other at 120 °.
Between each elastic member fixing | fixed part 74 and 64, the press comprised by the base end side part of the front end side linear part 20c, the bending parts 33h and 43f, and the front end side part of base end side linear part 20b and 20d A portion 75 is formed.

The pressing portion 75 is formed in a closed loop shape having a decagonal shape in which a linear portion extends between eight bending points and two fixing points by the elastic member fixing portions 74 and 64 when viewed in the radial direction from the radially outer side. Has been.
As shown in FIG. 24, for example, the pressing portion 75 formed by the linear elastic members 43A and 43C includes a proximal end portion of the distal end side linear portion 20cA, a bent portion 33hA, and a distal end of the proximal end linear portion 20dA. The broken line part comprised with the side part protrudes in one of the circumferential directions.
Further, a broken line portion constituted by the proximal end side portion of the distal end side linear portion 20cC, the bent portion 43fB, and the distal end side portion of the proximal end side linear portion 20bC is projected to the other side in the circumferential direction.
Of these, the bent portions 33hA and 43fB are such that the first portions h1 and f1 and the third portions h3 and f3 extend substantially along the circumferential direction of the electrode support portion 72, and the second portions h2 and f2 It is spaced apart in the direction and extends substantially parallel to the axial direction.
For this reason, as shown in FIG. 25, the bent portions 33hA and 43fB are arranged on the outermost periphery of the electrode support portion 72, and when inserted into the blood vessel, the bent portions 33hA and 43fB are portions that reliably contact the inner wall of the blood vessel. ing.

The other pressing portions 75 are formed in the same shape by the linear elastic members 43B and 43A and the linear elastic members 43C and 43B, respectively.
For this reason, the outer shape of the electrode support 72 has a shape that is three-fold rotationally symmetric with the central axis O as the rotational symmetry axis.
Further, the opening portion LP in the natural state is formed on the radially inner side of the bent portions 33h and 43f in each pressing portion 75.

As shown in FIGS. 26 (a) and 26 (b), when the electrode support 72 is inserted into the superior vena cava P3, first, each pressing portion 75 contacts the inner wall V1 mainly at the bent portions 33h and 43f. It is in contact and pressed radially inward. As a result, the opening LP is compressed radially inward via the elastic member fixing portions 74, and is deformed like the opening LP ′ (see FIG. 26B), so that the inner wall V1 has an inner diameter. The distal end side of each distal end side linear portion 20c is bent and extends radially outward. Thereby, each top part 20g of each front end side linear part 20c approaches or comes into contact with the inner wall V1, and when coming into contact, each top part 20g also presses the inner wall V1.
In FIGS. 26A and 26B, in order to make the illustration in the T view easier to see, each apex 20g is slightly separated from the inner wall V1 corresponding to the case where the inner wall V1 has a slightly larger diameter. Show.
However, the opening portion LP of the present embodiment has a closed loop shape with a fixed line length by being fixed by the elastic member fixing portion 74, and is a ring-shaped spring member that can expand and contract in the radial direction. For this reason, as shown in the figure, even when the top portions 20g are not in contact with the inner wall V1, reaction due to elastic restoring force due to deformation is applied to the elastic member fixing portion 74, and the pressing portion 75 is urged radially outward. Yes. The distance of each top 20g with respect to the inner wall V1 can be changed as appropriate by appropriately setting the crossing position where each elastic member fixing portion 74 is provided and adjusting the rigidity as the spring member.
With such a configuration, each pressing portion 75 is in a state in which the tip and the base end in the axial direction of the electrode support portion 72 are elastically supported by two linear portions, respectively, in the fourth embodiment. Like the pressing part 55, the inner wall V1 is equally pressed in three directions.
Thus, in the electrode support part 72, since the press part 75 is gathered in three places of the circumferential direction, it can press more firmly.
Thereby, the stimulation electrodes 21 and 22 can be more reliably and stably pressed against the inner wall V1.

  In addition, since each pressing portion 75 is mainly composed of bent portions 33h and 43f, the inner wall V1 is pressed in a band-shaped region in which the respective U-shaped openings are opposed to each other, and therefore, in the third embodiment. Thus, compared with the case where it presses only by the bending part 33h and the bending part 43f independently, the press range is wide and the contact length with the inner wall V1 per location also increases. Also in this respect, the pressing can be performed more stably, and the fixing position can be stabilized.

Thus, according to the electrode support part 72, the adjacent front end side linear part 20c is fixed by the elastic member fixing | fixed part 74 in an intersection position, and the press part 75 is formed, and the stimulation electrode 21 is formed in one of the press parts 75. , 22 is different from the electrode support portion 62 of the fifth embodiment only in that it is provided.
For this reason, since the opening part LP ′ is close to or in contact with the inner wall V1 in the medical electrical stimulation electrode 71, the blood flow is not easily inhibited as in the fifth embodiment, and the stimulation electrodes 21 and 22 are It can be stably pressed against the inner wall of the blood vessel.
In particular, since the pressing portion 75 is formed, the main pressing portion is formed at three locations that divide the inner wall of the blood vessel into three equal parts in the circumferential direction when inserted into the blood vessel, so that more stable pressing can be achieved. It becomes possible. For this reason, the indwelling position can be made more stable, and more stable electrical stimulation can be performed.

  In the description of each of the above embodiments, an example in which the linear elastic member is composed of three combinations has been described. However, four or more linear elastic members are combined to form a four-fold rotational symmetry or more. It is also possible.

  In the description of each of the above embodiments, as an example, the case where only one pair of stimulation electrode portions is provided on one elastic member has been described, but the number of stimulation electrode portions may be two or more pairs. Further, it is possible to provide a stimulation electrode portion on another linear elastic member.

  In the description of each of the above-described embodiments and modifications, the example in which the stimulation electrode unit is arranged in the superior vena cava to stimulate the vagus nerve is described as an example, and the stimulation electrode unit is the vagus nerve. It may stimulate other nerves. In this case, the stimulation electrode unit can be disposed in an appropriate blood vessel that can transmit the stimulation to the nerve that performs the stimulation.

Further, all the components described above can be implemented by being appropriately combined or deleted within the scope of the technical idea of the present invention.
For example, when the stimulation electrodes 21 and 22 are provided in the bent portion 33hA as in the second embodiment, the major axis direction (longitudinal direction) of the stimulation electrodes 21 and 22 intersects the traveling direction of the vagus nerve. Although it is preferable because it is possible to stably stimulate the circumferential movement of the support body portion 2, each of the bent portions 43 f of the third embodiment is provided in place of each of the bent portions 33 h, and the bent portion 43 f A is stimulated. It is also possible to provide the electrodes 21 and 22.

1, 31, 41, 51, 61, 71 Medical electrical stimulation electrode 2, 32, 42, 52, 62, 72 Electrode support part 3 Lead part 3a Lead tube 3b Tip part (end part of lead part)
3d Wiring unit 8 Electrical stimulation device 20, 20A, 20B, 20C, 33, 33A, 33B, 33C, 43, 43A, 43B, 43C Linear elastic member (linear elastic member)
20a, 20aA, 20aB, 20aC, 20e, 20eA, 20eB, 20eC Connecting end portion 20b, 20bA, 20bB, 20bC, 20d, 20dA, 20dB, 20dC Base end side linear portion (first linear portion)
20c, 20cA, 20cB, 20cC Front end side linear portion (second linear portion)
20f, 20fA, 20fB, 20fC, 20h, 20hA, 20hB, 20hC, 33h, 33hA, 33hB, 33hC, 43f, 43fA, 43hB, 43hC Bent part 20g, 20gA, 20gB, 20gC Top part 21, 22 Stimulation electrode part ,electrode)
23 Wire part 23a Wire body 25 Wiring 26 Outer sheath 26a Opening 27 Converging part 54, 64, 74 Elastic member fixing part 55, 75 Pressing part 100 Electrical stimulation system b1, d1, c1, c3 Base end side area b2, d2 Tip side Regions f1, h1 first part (third shaft-like part)
f2, h2 second part (intermediate shaft-like part)
f3, h3 third part (fourth shaft-like part)
LP, LP ′, LP ″, LP ′ ″ Opening O Central axis O1 First axis O2 Second axis O3 Third axis P Patient P2 Right external jugular vein (blood vessel)
P3 superior vena cava (blood vessel)
P6 Vagus nerve (nerve)
S1 plane (first plane)
S2 plane (second plane)
S3 plane V1, V2, V3 inner wall

Claims (7)

A medical electrical stimulation electrode for stimulating nerves from within a blood vessel,
A stimulating 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;
By combining three or more linear elastic members arranged at the end of the lead portion, the diameter gradually increases from the end portion of the lead portion along the central axis, and then substantially constant outside. The outer diameter is larger than the inner diameter of the blood vessel and converges on the diameter, and the outer diameter of the blood vessel is increased by the pressing force generated by elastic deformation in the radial direction with respect to the central axis in the blood vessel. An electrode support for pressing the inner wall ;
With
The elastic member is in a single natural state,
A pair of connecting end portions connected to the end portions of the lead portions, extending from each of the connecting end portions, formed in a substantially plane-symmetric loop shape with respect to the first plane;
In a second plane orthogonal to the first plane, a first linear portion facing the first plane across the first plane;
A second linear portion curved in a convex shape projecting to the side of the second plane;
A bent portion connecting an end of the first linear portion and an end of the second linear portion;
Have
In the natural state of the assembled state, the electrode support part,
While being arranged to be rotationally symmetric around the central axis, the second linear portion intersects with another adjacent second linear portion,
The top of the second linear portion is aligned on a concentric circle of the central axis, and the second linear portion forms a stretchable closed loop opening centered on the central axis .
The stimulation electrode portion is directed to a radially outer side with respect to the central axis at a position that can be in contact with the inner wall of the blood vessel in the periphery of the bent portion or the bent portion of the electrode support body portion. Arranged medical electrical stimulation electrode. The stimulation electrode part is
The medical electrical stimulation electrode according to claim 1, wherein the paired electrodes are arranged with a bent portion in one of the bent portions interposed therebetween. The bent portion is
A third linear portion projecting from the end of the first linear portion to the opposite side of the projecting direction of the second linear portion;
A fourth linear portion projecting from the end of the second linear portion to the opposite side of the projecting direction of the second linear portion;
An intermediate linear portion connecting the third linear portion and the fourth linear portion;
The medical electrical stimulation electrode according to claim 1, wherein the medical electrical stimulation electrode is formed in a U shape. The stimulation electrode part is
The electrode which makes a pair is arrange | positioned 1 each in the said 3rd linear part and the said 4th linear part in one of the said bending parts, The Claim 3 characterized by the above-mentioned. Medical electrical stimulation electrode. The elastic member is
The medical electrical stimulation electrode according to claim 3 or 4, wherein the medical elastic stimulation electrode is fixed to the other elastic member and the intermediate linear portion of each other. The elastic member is
The medical electrical stimulation electrode according to any one of claims 1 to 5, wherein the medical electrical stimulation electrode is fixed to at least a part of the other linear member and the first linear portion. The elastic member is
The medical electrical stimulation electrode according to any one of claims 1 to 6, wherein the medical elastic stimulation electrode is fixed at a position where the other elastic member and the second linear portion intersect each other.

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