JP2016067497A - Nerve stimulation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nerve stimulation system suppressing an electrode part from moving to a vessel when a lead part moves by body motion, while retaining operability at the time of dwelling.SOLUTION: A nerve stimulation system 1 includes: a fixation part 10 formed of a material with elasticity, and energizing the inner surface of a vessel by being dwelled inside the vessel in a state of being elastically deformed; at least a pair of electrode parts 20 provided in the fixation part; a lead part 30 formed in a linear shape and having a tip 31 attached to the fixation part; a sheath part 40 inserted with the lead part, and provided on the tip with an engaging part 56 provided at least one of the tip of the lead part and the fixation part, and an engaged part 44 engageable with an axis line C direction of the lead part, and an axis line periphery; and a sealing member provided in the sheath part, and watertightly-sealing an interval between the sheath part and the lead part. A base end side from the tip of the lead part is provided with a soft area 32 which transmits only elastic force of a dimension not allowing the fixation part to move to a vessel even when itself is deformed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a nerve stimulation system that stimulates neural tissue transvascularly.

Conventionally, research on nerve stimulation systems that perform treatment by applying electrical stimulation to nerve tissue has been performed. As one of the neural stimulation systems, a system is proposed in which a system is inserted into a blood vessel to stimulate nerve tissue adjacent to the blood vessel through the blood vessel wall.
As this type of nerve stimulation system, for example, the one described in Patent Document 1 is known. The nerve stimulation system includes a lead body (lead part) and a lead anchor (fixing part) provided at the tip of the lead body.
The lead body is flexible and usually has a circular cross section. The lead body includes a plurality of conductors including individual wires, coils, or cables. The conductor can be molded from an insulator such as, for example, silicone, polyurethane, ethylene-tetrafluoroethylene, or another biocompatible insulating polymer.
One or more electrodes (electrode portions) are arranged along the lead body.

The lead anchor includes a plurality of expandable struts extending from the proximal collar toward the distal end. The lead anchor is configured to spread from a folded shape to an expanded shape. When the lead anchor introduced into the blood vessel of the patient is in an expanded shape, the electrode is pressed against the blood vessel wall of the blood vessel, and the lead anchor is frictionally engaged with the blood vessel.
The lead anchor can be rotated within the blood vessel to orient the electrode to the target of stimulation, such as nerves, muscles, and the like. In addition, the lead body can be further rotated and aligned until a maximum or appropriate electrical stimulation threshold with electrodes for the nerve or muscle to be stimulated across the vessel wall is achieved.

Special table 2010-516405 gazette

In such a transvascular nerve stimulation system, it is important to fix the electrode in the blood vessel without displacement, and a fixing method using a biasing member for a stent has been proposed.
In general, in a nerve stimulation system, it is estimated that a point is fixed to a patient at a point inserted into a blood vessel such as the cervix, and a point within the blood vessel, for a total of two points. The problem here is body movements caused by moving the neck and arms while the patient is awake and turning over while sleeping. This body movement causes a change in the running shape of the blood vessel, elongation, and the like, and the lead portion also receives a tensile force or a pushing force. As a result, there is a concern that the fixed part moves relative to the blood vessel.
In order to avoid this, it is effective to absorb the external force from outside the body by softening the lead part or making the lead part into a spiral structure. However, even if the proximal end portion of the lead portion is moved, the soft lead portion absorbs the movement of the proximal end portion, and the distal end portion of the lead portion becomes difficult to move, and the operability of the lead portion is lowered.

  The present invention has been made in view of such problems, and suppresses movement of the electrode portion relative to the blood vessel even when the lead portion is moved by body movement while maintaining operability during placement. An object is to provide a neural stimulation system.

In order to solve the above problems, the present invention proposes the following means.
The nerve stimulation system according to the present invention is formed of an elastic material, and is provided in the fixing portion that biases the inner surface of the blood vessel by being placed in the blood vessel in an elastically deformed state. In addition, at least one pair of electrode portions, a lead portion formed in a linear shape with a tip portion attached to the fixing portion, and the lead portion are inserted, and provided at at least one of the tip portion and the fixing portion of the lead portion. A sheath portion provided at a distal end portion with an engaged portion capable of being engaged in an axial direction of the lead portion and the lead portion and around the axis, and the sheath portion and the lead portion. And a sealing member that seals water tightly between the distal end portion and the distal end portion of the lead portion so that the fixing portion does not move relative to the blood vessel even if it deforms. There is a soft region that transmits only the elastic force It is characterized by being.

Further, in the above nerve stimulation system, the proximal end portion from the contact position of the lead portion, which is a position where the sealing member contacts the lead portion when the engaging portion and the engaged portion are engaged. In the range up to, a rigid region for transmitting an elastic force large enough to move the fixed portion relative to the blood vessel is provided, and in the range from the proximal end side to the rigid region from the distal end portion, the flexible region is provided. More preferably, a region is provided.
In the above nerve stimulation system,
In the range from the contact position of the lead portion to the proximal end portion where the sealing member contacts in the lead portion when the engaging portion and the engaged portion are engaged, On the other hand, a hard region for transmitting an elastic force large enough to move the fixed portion is formed, and the tip portion has a hardness greater than or equal to the soft region between the soft region and the hard region in the lead portion. It is more preferable that a transition region is formed in which the base end portion has a hardness equal to or lower than the hard region and becomes harder toward the base end side.

In the above nerve stimulation system,
More preferably, the sheath part is formed with a side hole that reaches the inner peripheral surface of the sheath part from the outer surface of the sheath part and opens on the distal end side of the sealing member on the inner peripheral surface.
In the above nerve stimulation system, it is more preferable that the elastically deformed fixing portion can be accommodated in the conduit of the sheath portion.
In the above nerve stimulation system, it is more preferable that the lead portion is formed with a housing portion through which a stylet can be inserted.

Further, in the above nerve stimulation system, the fixed portion is formed in a linear shape, the distal ends thereof are connected to each other, the proximal ends thereof are connected, and the fixed portions are arranged to be separated from each other around the axis. A plurality of urging portions, and base end portions of the plurality of urging portions are the engaging portions, and the engaged portion protrudes from a distal end surface of the sheath portion and is adjacent to the periphery of the axis. It is more preferable to have a protrusion that can be inserted between the base end portions of the urging portion.
Further, in the above nerve stimulation system, the engaging portion has an engaging portion side receiving surface parallel to the axis, and the engaged portion is parallel to the axis, and the engaging portion side It is more preferable to have an engaged portion side receiving surface that can contact the receiving surface.

  According to the nerve stimulation system of the present invention, it is possible to suppress the movement of the electrode portion with respect to the blood vessel even when the lead portion is moved by body movement while maintaining the operability at the time of placement.

It is the side view which fractured | ruptured a part of the state in which the engaging part and engaged part in the nerve stimulation system of 1st Embodiment of this invention are not engaging. It is a principal part enlarged view in FIG. It is sectional drawing of the front of the lead part of the nerve stimulation system. It is the side view which fractured | ruptured a part of state in which the engaging part and the to-be-engaged part in the same nerve stimulation system are engaging. It is sectional drawing of cutting line A1-A1 in FIG. It is sectional drawing of the side surface of the base end side of the same nerve stimulation system. It is the side view which fractured | ruptured one part explaining the state by which the fixing | fixed part was accommodated in the sheath part of the same nerve stimulation system. It is a figure which shows the example of the waveform which the pulse generator used with the nerve stimulation system generate | occur | produces. It is a flowchart which shows the indwelling method of the same nerve stimulation system. It is a figure explaining the position of the opening formed in a patient. It is a figure explaining a state when the fixing | fixed part of the same nerve stimulation system is detained in the superior vena cava. It is the side view which fractured | ruptured a part of nerve stimulation system of 2nd Embodiment of this invention. It is the side view which fractured | ruptured a part of nerve stimulation system of 3rd Embodiment of this invention. It is the side view which fractured | ruptured a part of nerve stimulation system of 4th Embodiment of this invention. It is sectional drawing of the side surface of the base end side of the same nerve stimulation system. It is sectional drawing of the front of the nerve stimulation system in embodiment of the modification of this invention. It is sectional drawing of the front of the nerve stimulation system in embodiment of the modification of this invention. It is sectional drawing of the side surface of the nerve stimulation system in embodiment of the modification of this invention. It is a perspective view of the principal part of the nerve stimulation system in embodiment of the modification of this invention. It is a perspective view of the fixing | fixed part of the nerve stimulation system in embodiment of the modification of this invention. It is a perspective view of the fixing | fixed part of the nerve stimulation system in embodiment of the modification of this invention. It is a perspective view of the fixing | fixed part of the nerve stimulation system in embodiment of the modification of this invention. It is a perspective view of the fixing | fixed part of the nerve stimulation system in embodiment of the modification of this invention. It is a perspective view of the fixing | fixed part of the nerve stimulation system in embodiment of the modification of this invention. It is sectional drawing of the front of the lead | read | reed part of the nerve stimulation system in embodiment of the modification of this invention.

(First embodiment)
Hereinafter, a first embodiment of a nerve stimulation system according to the present invention will be described with reference to FIGS. 1 to 11. In all the drawings below, the thicknesses and dimensional ratios of the constituent elements are appropriately changed in order to make the drawings easy to see.
As shown in FIG. 1, the nerve stimulation system 1 includes a fixed portion 10 made of an elastic material, a pair of electrode portions 20 provided on the fixed portion 10, and a linearly formed tip portion 31. The lead part 30 attached to the fixing part 10, the sheath part 40 through which the lead part 30 is inserted, and an O-ring (sealing member, see FIG. 6) for sealing the space between the sheath part 40 and the lead part 30 50).
This nerve stimulation system 1 is used together with a pulse generator 60 which is a stimulation supply device.

The fixing portion 10 has a plurality of urging portions 11 which are formed in a linear shape and connected to each other's distal ends and to which their proximal ends are connected. Each urging portion 11 includes a wire (not shown) and an insulating coating 12 that covers the periphery of the wire. Each wire is made of a shape memory alloy or a super elastic wire made of a biocompatible material. As the material for forming the wire, a material that exhibits a restoring force to return the wire to its original shape when the external force is removed after the wire is deformed by applying an external force is used. The outer diameter of the wire is set to about 0.2 to 0.5 mm, for example, and the cross-sectional shape orthogonal to the longitudinal direction of the wire is circular, elliptical, rectangular or the like.
By applying the coating 12 around the wire, the smoothness of the outer peripheral surface of the wire can be improved, and a thrombus reduction effect and insulation can be imparted to the wire. For the coating 12, for example, polyurethane resin, polyamide resin, fluorine resin, or the like can be used. The thickness of the film 12 is, for example, 50 to 500 μm. Note that the coating 12 may not be provided on the wire.

The urging portions 11 are spaced apart from each other around the axis C of the lead portion 30 and are arranged around the axis C at equal angles (for example, every 90 ° if the number of urging portions 11 is four). Yes. An intermediate portion of each wire in the direction of the axis C is curved so as to protrude toward the direction away from the axis C, and the fixed portion 10 including the plurality of urging portions 11 has a substantially spherical shape as a whole.
The outer diameter of the fixed portion 10 in a natural state where no external force other than gravity is applied is about φ20 to 40 mm, which is larger than the inner diameter of the superior vena cava.

As shown in FIG. 2, when the fixing portion 10 configured as described above is inserted into a blood vessel such as the superior vena cava P1, the urging portion 11 is imaginary line L1 by the blood vessel wall P2 of the superior vena cava P1. By being deformed as shown, it is elastically compressed (deformed) toward the axis C side. As a reaction force against the compressive force of the blood vessel wall P2, the fixing portion 10 generates an elastic force generated by elastic deformation with respect to the blood vessel wall P2, that is, a pressing force that urges the inner surface of the superior vena cava P1 radially outward. The fixing portion 10 is fixed at a desired position in the superior vena cava P1 by the frictional force between the blood vessel wall P2 generated by the pressing force and the urging portion 11 of the fixing portion 10. Note that the fixed portion 10 extends in the direction of the axis C when compressed toward the axis C as indicated by the virtual line L1.
When the urging portions 11 are arranged around the axis C at equal angles, good operability of the fixed portion 10 can be obtained. However, the respective biasing portions 11 do not have to be arranged around the axis C at equal angles, for example, for fitting with a specific anatomy.

One of the plurality of urging portions 11 is provided with the pair of electrode portions 20 described above. Each electrode unit 20 is disposed between the wire and the coating 12. The electrode unit 20 is formed of platinum, a platinum iridium alloy, or the like.
An insulating partition film (not shown) exists between the electrode portion 20 and the wire, and the wire and the electrode portion 20 are electrically insulated. The electrode part 20 is formed, for example, in a ring shape on the partition film, and is formed by removing and exposing a part of the film 12 covering the electrode part 20. That is, as described later, when the fixing portion 10 is placed in the blood vessel, the electrode portion 20 is exposed in the blood vessel.
At this time, it is possible to give directionality to the position where the electrode portion 20 is provided, such as forming the electrode portion 20 so as to be exposed on the opposite side of the urging portion 11 from the axis C. The exposed area of the electrode part 20 is about 1-5 mm < ² >, for example. The pair of electrode portions 20 are arranged along the longitudinal direction of the urging portion 11 with an interval of, for example, about 3 to 20 mm.

  Each electrode portion 20 is electrically connected to the tip end portion of the electrical wiring 14 (see FIG. 3). As the electrical wiring 14, a stranded wire made of a nickel cobalt chrome alloy (35NLT 25% Ag material, 35NLT 28% Ag material, or 35NLT 41% Ag material) having bending resistance is used as an electrical insulating material (for example, ETFE having a thickness of 20 μm). Those coated with PTFE or the like can be suitably used. As will be described later, the electrical wiring 14 passes through the pipe 34 of the lead portion 30 and extends to the proximal end side.

The lead portion 30 is formed of a biocompatible material (for example, polyurethane resin or polyamide resin), and is made of a multi-lumen tube in which a pipe line 34 and a housing portion 35 are formed as shown in FIG. The pipe line 34 penetrates the lead part 30 in the axis C direction. The electrical wiring 14 is inserted into the conduit 34. The accommodation portion 35 is closed at the tip, and a known stylet D can be inserted therethrough. In order to improve the slidability with the stylet D, a film such as ETFE resin or PTFE resin may be formed on the inner surface of the accommodating portion 35.
The lead portion 30 is formed with the aforementioned distal end portion 31 shown in FIG. 1 and a soft region 32 on the proximal end side with respect to the distal end portion 31. The length of the flexible region 32 (length in the axis C direction) is about 100 mm or more.

The tip 31 and the soft region 32 are different in hardness, and the tip 31 is harder than the soft region 32. The distal end portion 31 has a hardness for transmitting an elastic force large enough to move the fixing portion 10 against a blood vessel such as the superior vena cava P1 against the frictional force described above. Note that the movement of the fixing unit 10 relative to the blood vessel here means both movement along the longitudinal direction of the blood vessel and movement (rotation) around the longitudinal direction of the blood vessel. On the other hand, the soft region 32 is a region that transmits only an elastic force that does not move the fixing unit 10 relative to the blood vessel even if it deforms.
Specifically, the Shore hardness (hereinafter abbreviated as “Shore hardness (D)”) measured using a type D durometer in accordance with JIS K7215 is the push-in operation (pushability) and rotation at the tip 31. It is 50 or more which has sufficient hardness with respect to operation, and more preferably 55 or more and 70 or less. The shore hardness (D) of the soft region 32 is not less than 10 and not more than 40, and is sufficiently soft. The Shore hardness (D) of the soft region 32 is more preferably 30 or less.
For joining the distal end portion 31 and the soft region 32, adhesion by a known adhesive, thermal welding, ultrasonic welding, or the like can be appropriately selected and used.
The dimensions of the lead part 30 are, for example, an outer diameter of about 0.8 to 2 mm and a length of about 500 to 900 mm. The inner diameter of the conduit 34 is, for example, about 0.3 to 0.6 mm, and the inner diameter of the accommodating portion 35 is, for example, about 0.4 to 0.8 mm.

As shown in FIGS. 4 and 5, the leading end portion 31 is formed with a lead-side protruding portion 36 that protrudes radially outward from the outer peripheral surface. The lead-side protrusion 36 is formed in an arc shape when viewed in the direction of the axis C shown in FIG. In this example, four lead side protrusions 36 are arranged around the axis C so as to be separated from each other at equal angles. The lead side protrusion 36 is made of the same material as the tip 31 and is formed integrally with the tip 31. In addition, you may form the front-end | tip part 31 and the lead side protrusion part 36 with the metal material which has biocompatibility, such as titanium and stainless steel.
As shown in FIG. 4, the engagement portion 56 is configured by the four lead-side protrusions 36 and the base end portions 11 a of the plurality of biasing portions 11. That is, in the present embodiment, the engaging portion 56 is provided on both the distal end portion 31 and the fixed portion 10 of the lead portion 30.

As shown in FIG. 1, the distal end portion 31 of the lead portion 30 is attached to the fixed portion 10, and a connector 37 for connecting to the pulse generator 60 is attached to the proximal end portion of the lead portion 30. As the connector 37, for example, a known IS-1 connector or other waterproof connector can be used. As shown in FIG. 3, the aforementioned electrical wiring 14 is inserted into the conduit 34 of the lead portion 30, and the proximal end portion of the electrical wiring 14 is connected to the connector 37.
In order to increase the tensile strength of the lead part 30, a tension member such as a metal wire may be inserted into the pipe line 34 of the lead part 30 or embedded in the lead part 30. Moreover, you may provide antithrombogenicity and slidability by giving arbitrary coatings on the surface of the lead part 30.

As shown in FIGS. 1 and 6, the sheath portion 40 includes a sheath main body 41 and a sheath hub 42 fixed to the proximal end portion of the sheath main body 41.
The sheath body 41 is formed of a biocompatible material such as polyurethane resin, polyamide resin, or fluororesin. The sheath hub 42 is formed in a cylindrical shape, and a stepped portion 42 a is formed at the distal end portion of the outer peripheral surface of the sheath hub 42 by reducing the outer diameter. The sheath hub 42 can be formed of the same material as the sheath body 41. The shore hardness (D) of the sheath main body 41 and the sheath hub 42 is substantially equal to the shore hardness (D) of the distal end portion 31 of the lead portion 30.
The overall dimensions of the sheath portion 40 are, for example, an outer diameter of about 2.5 to 2.9 mm, an inner diameter of about 1.5 to 2.5 mm, and a length of about 300 to 400 mm. A metal blade using stainless steel or tungsten may be enclosed in the resin forming the sheath body 41 to improve the rigidity and kink resistance of the sheath body 41.

As shown in FIGS. 4 and 5, an engaged portion 44 that can engage with the engaging portion 56 is provided on the inner peripheral surface of the distal end portion of the sheath body 41. The engaged portion 44 has four sheath-side protrusions 45 that protrude radially inward from the inner peripheral surface of the sheath body 41. The sheath side protrusion 45 is formed in a trapezoidal shape when viewed in the direction of the axis C shown in FIG. The four sheath side protrusions 45 are arranged around the axis C so as to be separated from each other at equal angles. The shore hardness (D) of the sheath side protrusion 45 is equal to the shore hardness (D) of the distal end portion 31 of the lead portion 30.
When the sheath side protrusion 45 is disposed between the lead side protrusions 36 adjacent to each other around the axis C, the sheath side protrusion 45 engages with the lead side protrusion 36 around the axis C. Further, at this time, the distal end surface of the sheath side projection 45 abuts on the base end portion 11a of the urging portion 11 so that the fixed portion 10 and the sheath side projection 45 are engaged in the axis C direction.
In addition, when the sheath side protrusion 45 is disposed between the lead side protrusions 36 adjacent to each other around the axis C, the fixed portion 10 and the sheath side protrusion 45 are configured not to engage in the axis C direction. Also good.

  The O-ring 50 has a known configuration made of rubber or the like, and is provided on the inner peripheral surface of the sheath hub 42 as shown in FIG. The distance from the distal end surface of the sheath body 41 to the O-ring 50 is determined based on the length in the direction of the axis C of the fixed portion 10 accommodated in the conduit 41a of the sheath body 41 by being compressed to the axis C side as will be described later. Also long. In the hole of the O-ring 50, the lead part 30 inserted through the sheath part 40 can slide in the direction of the axis C while being sealed watertight with the O-ring 50.

In the nerve stimulation system 1 configured as described above, the proximal end of the sheath portion 40 with respect to the lead portion 30 from the state in which the engaged portion 44 is disposed on the proximal end side with respect to the engaging portion 56 illustrated in FIG. When the portion is rotated about the axis C and moved (pushed in) toward the distal end, the sheath side protrusion 45 is disposed between the lead side protrusions 36 adjacent to the axis C as shown in FIGS. Then, the distal end surface of the sheath side protrusion 45 abuts on the proximal end portion 11 a of the urging portion 11. Thereby, the engaging part 56 and the to-be-engaged part 44 engage.
When the proximal end portion of the sheath portion 40 is further pushed into the lead portion 30, the urging portion 11 is elastically deformed toward the axis C side by being pushed by the engaged portion 44 of the sheath portion 40. Since the distance from the distal end surface of the sheath main body 41 to the O-ring 50 is set as described above, the deformed fixing portion 10 is accommodated in the conduit 41a of the sheath main body 41 as shown in FIG.

  The pulse generator 60 has an electrical stimulation supply unit (not shown) and can generate electrical stimulation by a constant current method or a constant voltage method. In this example, as shown in FIG. 8, a biphasic waveform group having a constant current method and a phase switching is generated as an electrical stimulus with a predetermined interval. As a specific waveform, for example, with a frequency of 5 to 20 Hz (hertz) and a pulse width of 50 to 400 ms (seconds), a positive maximum current of 0.25 to 20 mA (ampere) to a negative maximum current of −0.25 to −20 mA. Among them, the one in which the current changes can be mentioned. The pulse generator 60 applies such a biphasic waveform for an arbitrary number of seconds per minute. For example, when it is desired to apply the voltage intensively for 3 to 10 seconds, the time is 60 seconds.

  As described above, the pulse generator 60 is connected to the lead portion 30 via the connector 37. The connector 37 may be detachable from the pulse generator 60 or may be fixed to the pulse generator 60. When the pulse generator 60 and the lead unit 30 are connected, the electrical stimulation generated by the electrical stimulation supply unit is applied between the pair of electrode units 20 provided in the fixed unit 10 via the electrical wiring 14. . At that time, one of the paired electrode portions 20 acts as a plus electrode, and the other acts as a minus electrode.

Next, a procedure for placing the fixed portion 10 of the nerve stimulation system 1 configured as described above in the superior vena cava P1 will be described. FIG. 9 is a flowchart showing an indwelling method of the present nerve stimulation system 1. Note that the nerve stimulation system 1 is suitable for short-term nerve stimulation of, for example, several days, unlike the long-term nerve stimulation system in which the entire system is implanted in the patient's body.
First, the operator engages the engaging portion 56 and the engaged portion 44 in the direction of the axis C and around the axis C as shown in FIG. 4 outside the patient's body (step S10). The lead unit 30 is connected to the pulse generator 60 via the connector 37. As shown in FIG. 10, an opening P4 is formed by making a small incision near the neck of the patient P. A known introducer or dilator (not shown) is installed in the opening P4, and the tip of the introducer is inserted into the internal jugular vein (blood vessel) P5. The following description will be made using the internal jugular vein P5. However, in this procedure, the external jugular vein may be used instead of the internal jugular vein P5.

Next, the nerve stimulation system 1 is inserted into the internal jugular vein P5 from the fixed portion 10 side through the installed introducer (step S20). At this time, the fixing portion 10 is inserted after being elastically deformed (reduced diameter) to an outer diameter that can be inserted into the introducer. At the time of insertion, the positions of the electrode unit 20, the wire, and the electrical wiring 14 of the nerve stimulation system 1 are confirmed under fluoroscopy. Since the lead part 30 is slidable in the hole of the O-ring 50, the sheath part 40 can be moved in the axis C direction with respect to the lead part 30. Since the space between the sheath portion 40 and the lead portion 30 is sealed by the O-ring 50, body fluid such as blood does not flow out of the body through the space between the sheath portion 40 and the lead portion 30.
When the fixing portion 10 is inserted into the internal jugular vein P5, the inner diameter of the internal jugular vein P5 is smaller than the inner diameter of the superior vena cava P1, so that each urging portion 11 is elastically moved toward the axis C as shown in FIG. The fixed portion 10 is deformed to reduce the diameter as a whole and extends in the direction of the axis C. Thereby, the outer diameter of the fixing | fixed part 10 becomes smaller than the outer diameter in a natural state.

The surgeon pushes the base end portion of the sheath portion 40 or rotates it around the axis C under X-ray fluoroscopy. As described above, the sheath part 40, the sheath side protrusion 45, the lead side protrusion 36, and the tip part 31 are large enough to move the fixing part 10 against the blood vessel against the frictional force acting between the blood vessel. It is formed in the hardness which transmits the elastic force. For this reason, by pushing the proximal end portion of the sheath portion 40, the fixing portion 10 is pushed in the direction of the axis C with respect to the internal jugular vein P5, and by rotating the proximal end portion of the sheath portion 40 around the axis C, the inner portion The fixing part 10 rotates around the axis C with respect to the jugular vein P5 (step S30).
The neurostimulation system 1 and the stylet D are hardened as a whole by inserting the stylet D into the housing part 35 of the lead part 30 as necessary. By operating the proximal end portion of the sheath portion 40 and the proximal end portion of the stylet D together, the fixing portion 10 can be pushed in and rotated more easily.

  After insertion into the internal jugular vein P5, the pushing operation is performed as described above to deliver the fixing portion 10 to the superior vena cava P1. In the above description, the method of inserting the fixing portion 10 into the internal jugular vein P5 and delivering it to the superior vena cava P1 via the introducer has been described. However, there is also a method in which the introducer is delivered to the superior vena cava P1 and the nerve stimulation system 1 is inserted at that position so that the fixed portion 10 is delivered directly to the superior vena cava P1.

As shown in FIG. 11, the fixing portion 10 is roughly arranged in the superior vena cava P1. Also at this time, since the outer diameter of the fixed portion 10 in the natural state is set as described above, each biasing portion 11 is pressed to the axis C side by the superior vena cava P1. Since the pair of electrode portions 20 are formed so as to be exposed on the side opposite to the axis C in the urging portion 11, each electrode portion 20 is disposed so as to face the blood vessel wall P2 side of the superior vena cava P1, Each electrode part 20 can be reliably brought into contact with the blood vessel wall P2. It can suppress that the electrode part 20 contacts the blood in the superior vena cava P1, and can suppress that the electrical stimulation applied between a pair of electrode parts 20 leaks to the blood side so that it may mention later.
As shown in FIG. 11, a vagus nerve (nerve tissue) P6 is running adjacent to the superior vena cava P1.

Subsequently, the surgeon operates the pulse generator 60 to apply electrical stimulation between the pair of electrode portions 20. This applies an electrical stimulus to the living body. While applying electrical stimulation, the proximal end portion of the sheath portion 40 is pushed in to adjust the position of the fixing portion 10 along the longitudinal direction of the superior vena cava P1, and the proximal end portion of the sheath portion 40 is moved around the axis C. By rotating, the fixed portion 10 is rotated around the axis C. While moving the fixed part 10, the heart rate is measured by an electrocardiograph attached to the patient. When the pair of electrode portions 20 are arranged so as to approach the vagus nerve P6 and face each other, and the electrical stimulation applied to the vagus nerve P6 from the pair of electrode portions 20 becomes the largest, the heart rate of the patient is the highest. descend. The surgeon moves the fixing unit 10 so that the heart rate decreases most, that is, the pair of electrode units 20 face the vagus nerve P6 side.
Through the above procedure, the optimum position and orientation of the fixing unit 10 with respect to the superior vena cava P1 are determined (step S40).

Next, in a state where the proximal end portion of the lead portion 30 is gripped, only the proximal end portion of the sheath portion 40 is moved (retracted) to the proximal end side, and the engagement portion 56 and the engaged portion 44 are engaged. The match is released (step S50). In the series of procedures after step S50, care is taken so that the fixing unit 10 is not displaced with respect to the superior vena cava P1 by performing observation through X-ray fluoroscopy.
The distal end of the sheath portion 40 is moved from the fixed portion 10 to the proximal end side by about 100 mm. When pulling back the sheath portion 40, if the operation of pushing the lead portion 30 is interwoven, the displacement of the fixing portion 10 can be prevented.
Thereafter, the lead portion 30 is further pushed in and fed into the blood vessel, so that the lead portion 30 located in the blood vessel has a certain slack. When the placement in the superior vena cava P1 of the nerve stimulation system 1 is completed, the introducer is removed.

The nerve stimulation system 1 continues to apply electrical stimulation to the vagus nerve P6 for a certain period. During this time, even when the lead part 30 is moved by the patient's body movement, the flexible region 32 of the lead part 30 transmits only an elastic force large enough not to move the fixing part 10 relative to the blood vessel even if it deforms. It is not hard. For this reason, even if the force acting on the lead part 30 and transmitted to the flexible region 32 is further transmitted to the fixed part 10, the movement of the pair of electrode parts 20 relative to the superior vena cava P1 is suppressed. It is done. If the length of the flexible region 32 is about 100 mm, the body motion of the patient P can be absorbed after the placement.
When the predetermined period of time has elapsed, the pulse generator 60 is operated to stop the generation of electrical stimulation. Since the outer diameter of the fixing portion 10 easily changes, the nerve stimulation system 1 can be extracted even from the small opening P4 by pulling the lead portion 30 back. Surgical reoperation is not required for removal of the system 1.
Thereafter, an appropriate treatment such as suturing the opening P4 is performed, and the series of procedures is completed.

In the present embodiment, the nerve stimulation system 1 may be inserted into the internal jugular vein P5 through the introducer in a state where the fixing portion 10 is accommodated in the conduit 41a of the sheath body 41. In this case, when the fixing portion 10 in the sheath main body 41 comes out from the distal end of the introducer, the operator pushes the lead portion 30 into the blood vessel while holding the proximal end portion of the sheath portion 40, and the sheath portion 40. Is retracted relative to the lead portion 30. At this time, if the stylet D is inserted into the accommodating portion 35 of the lead portion 30 to give rigidity, the operation is easy to perform. The lead portion 30 is pushed in until the fixing portion 10 protrudes from the distal end of the sheath portion 40, and the engaging portion 56 and the engaged portion 44 are engaged. The subsequent procedure at the time of detention is as described above.
In addition, when removing the nerve stimulation system 1, you may accommodate the fixing | fixed part 10 in the pipe line 41a. In this case, the operator pulls back the lead part 30 while holding the proximal end part of the sheath part 40, and advances the sheath part 40 relative to the lead part 30. When the fixing part 10 is accommodated in the duct 41a of the sheath part 40, the sheath part 40 is pulled back from the blood vessel, and the removal is completed.

As described above, according to the nerve stimulation system 1 of the present embodiment, the base end of the sheath portion 40 is obtained by engaging the engaging portion 56 and the engaged portion 44 in the direction of the axis C and around the axis C. The force for operating the part is transmitted to the fixed part 10 through the sheath part 40, the engaged part 44, the engaging part 56, and the tip part 31. That is, when the proximal end portion of the sheath portion 40 is pushed, the fixing portion 10 is pushed into the blood vessel, and when the proximal end portion of the sheath portion 40 is rotated around the axis C, the fixing portion 10 rotates around the axis C within the blood vessel. To do. For this reason, the operativity of the nerve stimulation system 1 at the time of indwelling can be maintained as usual.
When the fixing portion 10 is positioned with respect to the superior vena cava P1, the engagement between the engaging portion 56 and the engaged portion 44 is released. In this way, even when the lead part 30 is moved due to the body movement of the patient P, a pair of electrode parts is provided for the superior vena cava P1 in order to reduce the force transmitted by the flexible region 32 of the lead part 30. 20 can be prevented from moving.

By applying electrical stimulation to the vagus nerve P6 through the blood vessel wall P2 of the superior vena cava P1, it is possible to apply electrical stimulation indirectly without directly contacting the vagus nerve P6. Therefore, treatment can be performed with minimal invasiveness.
When applying electrical stimulation to the vagus nerve P6, the target nerve stimulation can be realized without giving a large surgical invasion to the target nerve tissue. The placement of the nerve stimulation system 1 can be realized by a general transvenous approach that is frequently used in catheter procedures. Since the electrical stimulation is indirectly applied, it is possible to complete the installation in a short time without worrying about the damage of the nerve tissue when the nerve stimulation system 1 is installed, and to quickly remove the nerve stimulation system 1 after the treatment. it can.

Since the fixing portion 10 can be accommodated in the conduit 41a of the sheath body 41, the nerve stimulation system 1 can be inserted into the superior vena cava P1 in a state where the fixing portion 10 is accommodated in the conduit 41a. . Thereby, when inserting through an introducer, an operator does not need to reduce the diameter of the fixing | fixed part 10, and it can prevent that force, such as twist more than necessary, is applied to the wire of the fixing | fixed part 10. FIG.
The outer diameter of the sheath part 40 when the nerve stimulation system 1 is removed in a state where the fixing part 10 is accommodated in the duct 41a is smaller than the diameter of the opening P4. Therefore, the risk of damaging the blood vessel wall can be further reduced.
In this way, the nerve stimulation system 1 can be inserted into the blood vessel more quickly and safely.

  Since the accommodation part 35 is formed in the lead part 30, when the stylet D is inserted into the accommodation part 35, the nerve stimulation system 1 and the stylet D become hard as a whole. Therefore, the fixing part 10 can be pushed in and rotated more easily.

In recent years, in the field of treatment of chronic heart failure, it has become known that by using a nerve stimulation system that directly applies electrical stimulation to the autonomic nerve, circulatory dysregulation can be corrected and prognosis can be improved. It was.
By using the nerve stimulation system 1 of the present invention, it is possible to reduce arrhythmia and cardiac remodeling phenomena that occur after reperfusion treatment during acute myocardial infarction. By applying electrical stimulation to the vagus nerve for a certain period after reperfusion treatment, the heart load is reduced through the effects of lowering the heart rate of the parasympathetic nervous system, sympathetic nerve antagonism, anti-inflammatory action, and myocardial regeneration. , Cardiac remodeling can be reduced.
In the reperfusion treatment, it is also possible to stimulate the vagus nerve P6 using the nerve stimulation system 1 of the present invention before reperfusion. Thereby, generation | occurrence | production of the arrhythmia immediately after reperfusion can be suppressed notably.

In the present embodiment, the engaging portion 56 has four lead-side protrusions 36, and the engaged portion 44 has four sheath-side protrusions 45. However, the number of lead-side protrusions 36 included in the engaging portion 56 and the number of sheath-side protrusions 45 included in the engaged portion 44 are not limited, and any number may be used as long as both are one or more. However, the larger the number of lead side protrusions 36 and the number of sheath side protrusions 45, the easier the engagement.
Specifically, in the present embodiment, the number of the lead-side protrusions 36 and the number of the sheath-side protrusions 45 are each four, so that the engaged portion 44 is around the axis C with respect to the engaging portion 56. Engage in four positions (orientations). For example, when the number of the lead side protrusions 36 and the number of the sheath side protrusions 45 are each eight, the engaged portion 44 is engaged with the engagement portion 56 at eight positions around the axis C. And the ease of engagement is doubled.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. 12, but the same parts as those of the above-described embodiment will be denoted by the same reference numerals, description thereof will be omitted, and only different points will be described.
As shown in FIG. 12, the nerve stimulation system 2 of the present embodiment includes a lead portion 70 instead of the lead portion 30 of the nerve stimulation system 1 of the first embodiment, and the O-ring 50 is the inner peripheral surface of the sheath body 41. Is provided. Further, due to the small inner diameter of the engaged portion 44, the fixing portion 10 is not accommodated in the conduit 41 a of the sheath body 41 even if the proximal end portion of the sheath portion 40 is pushed in strongly.

The lead portion 70 is in contact with the aforementioned distal end portion 31, the soft region 71 provided in contact with the distal end portion 31 on the proximal end side of the distal end portion 31, and the soft region 71 on the proximal end side of the flexible region 71. And a hard region 72 provided in a state.
Here, the contact position Q1 of the lead part 70, which is the position where the O-ring 50 contacts the lead part 70 when the engaging part 56 and the engaged part 44 are engaged, is defined. The hard region 72 is provided in a range from the contact position Q <b> 1 to the proximal end portion of the lead portion 70. The soft region 71 is provided in a range from the proximal end side to the hard region 72 with respect to the distal end portion 31. The length of the flexible region 71 is, for example, about 100 mm.
The shore hardness (D) of the soft region 71 is equal to the shore hardness (D) of the soft region 32 of the lead portion 30 described above, and the shore hardness (D) of the hard region 72 is equal to the tip portion 31 of the lead portion 30. Equal to Shore hardness (D).

  Since the fixing portion 10 is not accommodated in the conduit 41 a of the sheath body 41, the O-ring 50 provided in the sheath portion 40 is in the contact position Q 1 in the lead portion 70 even when the sheath portion 40 is pushed into the lead portion 70. Does not move to the tip side. The O-ring 50 does not contact the soft region 71. In other words, the O-ring 50 does not reach the soft region 71.

Next, a procedure for placing the nerve stimulation system 2 configured as described above will be described.
When the position of the fixing portion 10 with respect to the superior vena cava P1 is determined, the operator moves only the proximal end portion of the sheath portion 40 toward the proximal end side while holding the proximal end portion of the lead portion 70 (retracts it). ), The engagement between the engaging portion 56 and the engaged portion 44 is released. Thereafter, the lead portion 70 is pushed in with the proximal end portion of the sheath portion 40 held, and the sheath portion 40 is moved backward relative to the lead portion 70. Since the O-ring 50 contacts the hard region 72 without contacting the soft region 71, the lead portion 70 expands and contracts in the axis C direction even when a frictional force is generated between the O-ring 50 and the lead portion 70. Thus, the surgeon can perform the pushing operation efficiently.
Also in this embodiment, since the length of the soft region 71 is about 100 mm, the body motion of the patient P can be absorbed after indwelling.

As described above, according to the nerve stimulation system 2 of the present embodiment, the pair of electrode portions 20 moves with respect to the blood vessel even when the lead portion 70 moves due to body movement while maintaining the operability during placement. Can be suppressed.
Further, in the lead portion 70, a hard region 72 is provided in a range from the contact position Q <b> 1 to the base end portion, and a soft region 71 is provided between the distal end portion 31 and the hard region 72. For this reason, the surgeon can perform the pushing operation efficiently.

  In the present embodiment, the O-ring 50 is provided on the inner peripheral surface of the sheath body 41. However, if the O-ring 50 is in contact with the hard region 72 when the engaging portion 56 and the engaged portion 44 are engaged, the O-ring 50 is provided on the inner peripheral surface of the sheath hub 42. Also good.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. 13, but the same parts as those of the above-described embodiment will be denoted by the same reference numerals, the description thereof will be omitted, and only different points will be described.
As shown in FIG. 13, the nerve stimulation system 3 of this embodiment includes a lead portion 80 instead of the lead portion 70 of the nerve stimulation system 2 of the second embodiment.
The lead portion 80 includes the distal end portion 31 and the soft region 71, the transition region 81 provided in contact with the soft region 71 on the proximal end side of the soft region 71, and the transition region on the proximal end side of the transition region 81. 81 and the above-mentioned hard region 72 provided in contact with 81. That is, the transition region 81 is formed between the soft region 71 and the hard region 72 in the lead portion 80. The length of the transition region 81 is, for example, about 80 to 110 mm.

The transition region 81 has a shore hardness (D) with a distal end portion having a shore hardness (D) of the soft region 71 or more and a proximal end portion having a shore hardness (D) of the hard region 72 or less. ) Is large (hard).
As a method of configuring the shore hardness (D) of the transition region 81 as described above, for example, the raw material that forms the soft region 71 and the raw material that forms the hard region 72 are arranged side by side in an extruder, and the soft region 71 is arranged. The method of extruding in order from the raw material which forms can be mentioned. The boundary portion between the raw material of the soft region 71 and the raw material of the hard region 72 is formed in a state where both raw materials are mixed, and therefore, a transition region 81 in which the Shore hardness (D) increases toward the base end side is formed. Can be manufactured.

As described above, according to the nerve stimulation system 3 of the present embodiment, the pair of electrode portions 20 moves with respect to the blood vessel even when the lead portion 80 moves due to body movement while maintaining the operability during placement. Can be suppressed.
Further, a transition region 81 is formed in the lead portion 80. As a result, since the Shore hardness (D) gradually increases between the soft region 71 and the hard region 72, the shape of the lead portion 80 is greatly deformed locally when the lead portion 80 is bent. The lead part 80 can be held in a shape more along the blood vessel.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. 14 and FIG. 15. The same parts as those of the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted. explain.
As shown in FIGS. 14 and 15, the nerve stimulation system 4 of the present embodiment includes a sheath portion 90 instead of the sheath portion 40 of the nerve stimulation system 1 of the first embodiment.
The sheath portion 90 includes a sheath hub 91 formed in a tubular shape instead of the sheath hub 42 of the sheath portion 40. The sheath hub 91 is formed with a side hole 91 c that reaches the inner peripheral surface 91 b of the sheath hub 91 from the base end surface 91 a that is the outer surface of the sheath hub 91. The side hole 91 c opens on the distal end side of the inner peripheral surface 91 b of the sheath hub 91 with respect to the O-ring 50.

  A distal end portion of a tube 96 made of resin or the like is fixed to the base end surface 91a of the sheath hub 91 with an adhesive or the like. The conduit of the tube 96 communicates with the side hole 91c. For example, a known luer lock type connector 97 is attached to the base end portion of the tube 96. A connector such as a syringe (not shown) can be attached to the connector 97. The syringe contains a liquid such as an anticoagulant, a diluted solution of the anticoagulant, physiological saline, or a contrast medium.

In the procedure of placing the nerve stimulation system 4 configured as described above, when the syringe is operated to extrude the liquid, the liquid passes through the tube 96, the side hole 91c of the sheath hub 91, and the cylindrical hole of the sheath hub 91. Flows in. Since the O-ring 50 is provided, the liquid does not flow to the proximal end side but is discharged from the distal end of the sheath portion 90 to the outside.
When an anticoagulant and an anticoagulant diluent are used as the liquid, it is possible to suppress the formation of thrombus while the nerve stimulation system 4 is placed in the blood vessel. In the case where physiological saline is used as the liquid, it is possible to suppress the adhesion of platelets to the nerve stimulation system 4 by creating a liquid flow around the nerve stimulation system 4 and, as a result, to suppress thrombus generation. it can. When a contrast medium is used as the liquid, the position of the electrode unit 20 can be confirmed under fluoroscopy during the placement procedure.

As described above, according to the nerve stimulation system 4 of the present embodiment, it is possible to suppress the movement of the pair of electrode portions 20 relative to the blood vessel even when the lead portion 30 is moved by body movement.
Furthermore, the fluid can be discharged to the outside from the tip of the sheath portion 90 through the side hole 91c.

The first to fourth embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the configuration does not depart from the gist of the present invention. Changes, combinations, deletions, etc. Furthermore, it goes without saying that the configurations shown in the embodiments can be used in appropriate combinations.
For example, in the first to fourth embodiments, the configuration of the engaging portion 56 and the engaged portion 44 can be variously modified as described below.
As shown in FIG. 16, two engaging portion side receiving surfaces 101 are formed on the outer peripheral surface of the distal end portion 31 of the lead portion 30 in place of the aforementioned lead side protruding portion 36, and the sheath main body 41 of the sheath portion 40 is formed. Instead of the sheath side protrusion 45, two engaged portion side receiving surfaces 106 may be formed on the inner peripheral surface of the distal end portion.
The two engaging portion side receiving surfaces 101 and the base end portion 11a of the biasing portion 11 constitute an engaging portion 102, and the two engaged portion side receiving surfaces 106 and the distal end surface of the sheath body 41 are engaged portions. 107 is configured.

Each engaging portion side receiving surface 101 is a flat surface, is formed in parallel to the axis C, and is disposed on the opposite side across the axis C. By forming the engaging portion side receiving surface 101, the tip portion 31 is so-called D-cut. Each engaged portion side receiving surface 106 is a flat surface, is formed in parallel with the axis C, and is disposed so as to face the axis C.
When the engaged portion side receiving surface 106 comes into contact with the engaging portion side receiving surface 101, the engaged portion side receiving surface 106 is engaged with the engaging portion side receiving surface 101 around the axis C. When the distal end surface of the sheath main body 41 abuts on the proximal end portion 11a of the urging portion 11, the fixing portion 10 and the sheath main body 41 are engaged in the axis C direction.
Also by the engaging part 102 and the engaged part 107 configured as described above, the same effects as those of the engaging part 56 and the engaged part 44 of the first embodiment can be obtained.

In this modification, the engaging portion 102 has two engaging portion side receiving surfaces 101, and the engaged portion 107 has two engaged portion side receiving surfaces 106. However, the number of the engaging portion side receiving surfaces 101 included in the engaging portion 102 and the number of the engaged portion side receiving surfaces 106 included in the engaged portion 107 are not limited, and may be any number as long as they are the same number.
For example, in the modification shown in FIG. 17, the engaging portion 102 </ b> A has four engaging portion side receiving surfaces 101, and the engaged portion 107 </ b> A has four engaged portion side receiving surfaces 106. The four engaging portion side receiving surfaces 101 are formed around the axis C at equal angles, and the four engaged portion side receiving surfaces 106 are formed around the axis C at equal angles.
As the number of the receiving surfaces 101 and 106 increases, the engaging portion and the engaged portion are easily engaged. Further, as the number increases, the force applied to the engaging portion when performing the rotation operation is dispersed, which leads to improvement in operability and prevention of biting.

As shown in FIG. 18, an engaging portion 104, which is a male screw, is provided at the distal end portion 31 of the lead portion 30, and a female screw that is screwed into the engaging portion 104 on the inner peripheral surface of the distal end portion of the sheath body 41. A certain engaged portion 109 may be provided. Both the engaging portion 104 and the engaged portion 109 are formed with thread grooves that increase in diameter toward the distal end side. From the state where the engaged portion 109 is closer to the proximal end than the engaging portion 104, the engaged portion 104 and the engaged portion are rotated by rotating the engaged portion 109 in a predetermined direction around the axis C while pushing. 109 and the engaged portion 109 cannot be pushed.
In this state, the engaging portion 104 and the engaged portion 109 are engaged in a predetermined direction around the axis C, and are engaged on both the distal end side and the proximal end side in the axis C direction.
Note that the engagement portion 104 and the engaged portion 109 can be unscrewed by pulling the engaged portion 109 around the axis C while rotating it in a direction opposite to a predetermined direction.

As shown in FIG. 19, the engaging portion 111 is configured by the base end portion 11 a of each urging portion 11, and the engaged portion 116 provided at the distal end portion of the sheath body 41 is the distal end surface of the sheath body 41. You may comprise so that it may have the some protrusion part 117 which protrudes from. The plurality of projecting portions 117 are arranged so as to be separated from each other around the axis C, and constitute a so-called claw structure.
In this modification, the projecting portion 117 inserted between the base end portions 11a of the urging portions 11 adjacent to each other around the axis C engages with the base end portion 11a, so that the engaging portion 111 and the engaged portion 111 are engaged. The part 116 engages around the axis C. Further, when the distal end surface of the sheath body 41 comes into contact with the proximal end portion 11a of the biasing portion 11, the engaging portion 111 and the engaged portion 116 are engaged in the axis C direction.
Also by the engaging part 111 and the engaged part 116 configured as described above, the same effects as the engaging part 56 and the engaged part 44 of the first embodiment can be obtained.
In this modification, the engaged portion 116 has a plurality of protruding portions 117, but the engaged portion 116 may have a single protruding portion 117.

Moreover, in the said 1st Embodiment to 4th Embodiment, the fixing | fixed part 10 can change the structure variously so that it may demonstrate below. 20 to 24, the engaging portion is not shown.
Like the fixing portion 120 shown in FIG. 20, in addition to the components of the fixing portion 10 of the first embodiment, a needle portion 121 that protrudes toward the distal end side is provided on the distal end side of each biasing portion 11, and You may provide the needle part 122 which protrudes toward the base end side in the base end side of each urging | biasing part 11. As shown in FIG. In the fixing part 120 configured as described above, the fixing part 120 can be positioned in the superior vena cava P1 by puncturing the blood vessel wall P2 with the needle parts 121 and 122.

21 has a rod-like support member 131 extending from the tip end portion 31 toward the tip end, and a biasing portion 11 curved so as to protrude from the support member 131 toward one side (one side) with respect to the axis C. Is provided. In this modification, the pair of electrode portions 20 are provided on the support member 131. The support member 131 is formed of an insulating resin or the like.
The fixing portion 140 shown in FIG. 22 has a so-called stent-like (cylindrical) biasing member 141 formed of a resin having insulating properties and elasticity. A large number of holes 141 a are formed on the side surface of the urging member 141. By disposing the biasing member 141 in the superior vena cava P1 with the diameter reduced, the fixing portion 140 is positioned in the superior vena cava P1.

In the fixing portion 150 shown in FIG. 23, the support wires 151 and 152 are formed on the same plane in the natural state. The support wires 151 and 152 can be formed by bending a superelastic wire. The support wires 151 and 152 are folded and reduced in diameter and introduced into the blood vessel. The support wires 151 and 152 are expanded in the superior vena cava P1 and the vessel wall P2 is urged to be fixed to the superior vena cava P1. Position part 150.
In the fixing portion 160 shown in FIG. 24, the support wire 161 is curved so as to be convex toward the axis C. The radius of curvature of the support wire 161 when viewed in the direction of the axis C is larger than the inner diameter of the superior vena cava P1. The support wire 161 is introduced into the blood vessel in a state of being elastically deformed so as to reduce the radius of curvature, and the support wire 161 is expanded in the superior vena cava P1 to urge the blood vessel wall P2 with the support wire 161. Then, the fixing portion 160 is positioned in the superior vena cava P1.

In the first to fourth embodiments, the lead portion is a multi-lumen tube in which the conduit 34 and the accommodating portion 35 are formed. However, as shown in FIG. 25, the lead portion 170 may be configured by accommodating auxiliary tubes 171 and 172 having a relatively small outer diameter in a main tube 173 having a relatively large outer diameter. In this modification, the electrical wiring 14 is inserted into the auxiliary tube 171, and the stylet D can be inserted into the auxiliary tube 172.
By configuring the lead part 170 in this way, the cross-sectional area perpendicular to the axis C is smaller than that of the lead part 30, and the lead part 170 is easily bent.

In the first to fourth embodiments, a pair of electrode portions 20 are provided in one urging portion 11. However, the number of the electrode parts 20 provided in this one urging | biasing part 11 is not restricted to a pair, ie, two, Three or more may be sufficient.
When the sheath portion 40 is relatively hard, the stylet D accommodating portion 35 may not be formed in the lead portion 30.
The nerve stimulation system is described as being placed in the superior vena cava P1 and applying electrical stimulation to the vagus nerve P6. However, the neural stimulation system is not limited to this, and can be used for a cardiac pacing lead, for example.

Furthermore, the present invention includes the following technical ideas.
(Additional item 1)
A fixed portion formed of an elastic material; a lead portion formed in a linear shape with a tip portion attached to the fixed portion; and a sheath portion through which the lead portion is inserted; and A nerve stimulation system in which a soft region that transmits only an elastic force large enough not to move the fixing portion relative to the blood vessel even if it deforms is placed in the blood vessel on the proximal side of the distal end portion. A method of placing a nerve stimulation system,
An engaging portion provided at at least one of the tip portion and the fixing portion of the lead portion and an engaged portion provided at the tip portion of the sheath portion are engaged in the axial direction of the lead portion and around the axis line. Combine
Inserting the fixed part elastically deformed into the blood vessel,
By operating the proximal end of the sheath part, the fixed part is pushed in the axial direction, or rotated around the axial line,
The nerve stimulation system is placed in the blood vessel in a state where the sheath portion is pulled back to release the engagement between the engaging portion and the engaged portion.

1, 2, 3, 4 Neural stimulation system 10, 120, 130, 140, 150, 160 Fixing part 11 Energizing part 20 Electrode part 30, 70, 80, 170 Lead part 31 Tip part 32, 71 Soft area 35 Housing part 40, 90 Sheath part 41a Pipe line 44, 107, 107A, 109, 116 Engaged part 50 O-ring (sealing member)
56, 102, 102A, 104, 111 Engaging portion 72 Hard region 81 Transition region 91a Base end surface (outer surface)
91b inner peripheral surface 91c side hole 101 engaging portion side receiving surface 106 engaged portion side receiving surface 117 projecting portion C axis D stylet P1 superior vena cava (blood vessel)
P5 Internal jugular vein (blood vessel)
Q1 contact position

Claims (8)

A fixing portion that is formed of an elastic material and is elastically deformed and placed in the blood vessel to urge the inner surface of the blood vessel;
At least a pair of electrode portions provided on the fixed portion;
A lead portion formed in a linear shape and having a tip attached to the fixed portion;
The lead portion is inserted, and an engagement portion provided at at least one of the tip portion and the fixing portion of the lead portion, and an engaged portion engageable in the axial direction of the lead portion and around the axis line A sheath part provided in the part;
A sealing member that is provided in the sheath portion and seals between the sheath portion and the lead portion in a water-tight manner;
With
A soft region that transmits only an elastic force that does not move the fixing portion relative to the blood vessel even when the lead portion deforms is provided on the proximal end side of the distal end portion of the lead portion. Neural stimulation system. In the range from the contact position of the lead portion to the base end portion, which is the position where the sealing member contacts the lead portion when the engaging portion and the engaged portion are engaged, On the other hand, a rigid region for transmitting an elastic force of a size that moves the fixed portion is provided,
The nerve stimulation system according to claim 1, wherein the soft region is provided in a range from a base end side to the hard region with respect to the distal end portion. In the range from the contact position of the lead portion to the proximal end portion where the sealing member contacts in the lead portion when the engaging portion and the engaged portion are engaged, On the other hand, a rigid region that transmits an elastic force of a size that moves the fixed portion is formed,
Between the soft region and the hard region in the lead portion, the tip is harder than the soft region and the base end is harder than the hard region and hardens toward the base end. The nerve stimulation system according to claim 1, wherein a transition region is formed.   The sheath portion is formed with a side hole that reaches the inner peripheral surface of the sheath portion from the outer surface of the sheath portion and opens on the distal end side of the sealing member on the inner peripheral surface. The nerve stimulation system according to claim 1.   The nerve stimulation system according to claim 1, wherein the elastically deformed fixing portion can be accommodated in a pipe line of the sheath portion.   The nerve stimulation system according to claim 1, wherein the lead portion is formed with a housing portion through which a stylet can be inserted. The fixed portion is formed in a linear shape, and has a plurality of urging portions that are arranged so as to be separated from each other around the axis line, with the distal end portions thereof being connected to each other and the proximal end portions being connected to each other.
Proximal end portions of the plurality of urging portions are the engaging portions,
The said engaged part has a protrusion part which protrudes from the front end surface of the said sheath part, and can be inserted between the base end parts of the said urging | biasing part adjacent to the surroundings of the said axis line. Nerve stimulation system. The engagement portion has an engagement portion side receiving surface parallel to the axis,
2. The nerve according to claim 1, wherein the engaged portion has an engaged portion side receiving surface that is parallel to the axis and can contact the engaging portion side receiving surface. Stimulation system.

Images