JP2016140508A - Nerve stimulation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nerve stimulation system capable of, when indwelt, preventing the electrode parts from moving relative to a blood vessel even if the lead part is moved by body motion while keeping the operability unchanged.SOLUTION: A nerve stimulation system 1 comprises: a stationary part for energizing inner surfaces of a blood vessel; at least a pair of electrodes mounted to the stationary part; a lead part 40 formed linearly and attached to the stationary part at the distal part thereof; and a sheath part 50 through which the lead part is inserted. A portion closer to the proximal part than the distal part of the lead part is provided with a soft part which transmits only an elastic force of a magnitude not to move the stationary part relative to the blood vessel even if the soft part itself deforms. The sheath part includes: a sheath tip part 51 constituting the proximal part of the sheath and provided with an engaged part; and a sheath body part 52 arranged in a portion closer to the proximal part than the sheath tip part. When the sheath body part is circumferentially pulled and axially torn to form a break 52a at least in part of the sheath body in a longitudinal direction of the sheath body part, the lead part can be removed out of the sheath body part through the break in the body part.SELECTED DRAWING: Figure 11

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 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 The sheath portion constitutes a distal end portion of the sheath portion, and includes a sheath distal end portion provided with the engaged portion, and a sheath main body portion disposed on a proximal end side with respect to the sheath distal end portion. The sheath body portion is formed by pulling the sheath body portion in the circumferential direction and tearing the sheath body portion in the axial direction to form a body side cut in at least a part of the longitudinal direction of the sheath body portion. The lead portion can be taken out to the outside of the sheath main body portion.

Further, in the above nerve stimulation system, the sheath distal end is formed by extending the sheath distal end in the circumferential direction, tearing in the axial direction, and forming a distal end cut along the entire length in the longitudinal direction of the sheath distal end. More preferably, the lead portion can be taken out of the sheath distal end portion through the distal end-side cut.
Further, in the above nerve stimulation system, the sheath part is formed in a tubular shape and disposed on the proximal end side of the sheath body part, and the lead part holds the lead part in the axial direction and can release the holding. Having a holding mechanism, the lead part holding mechanism pulls the lead part holding mechanism in the circumferential direction, tears in the axial direction, and forms a holding side cut across the entire length in the longitudinal direction of the lead part holding mechanism, More preferably, the lead part can be taken out of the lead part holding mechanism through the holding side cut.

  Further, in the above nerve stimulation system, the sheath portion is formed in a tubular shape and disposed on the proximal end side of the sheath main body portion, and the force acting between the lead portion and the sealing member can be adjusted. A sealing force adjusting mechanism, the sealing force adjusting mechanism pulls the sealing force adjusting mechanism in the circumferential direction, tears in the axial direction, and covers the entire length in the longitudinal direction of the sealing force adjusting mechanism. More preferably, by forming the cut, the lead portion can be taken out of the sealing force adjusting mechanism through the sealing-side cut.

  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 in the nerve stimulation system of 1st Embodiment of this invention. It is a principal part enlarged view in FIG. It is sectional drawing of cutting line A1-A1 in FIG. It is sectional drawing of the principal part of the nerve stimulation system. It is sectional drawing of cutting line A2-A2 in FIG. It is sectional drawing of cutting line A3-A3 in FIG. It is sectional drawing of the side surface of the base end side of the same nerve stimulation system. It is a figure which shows the example of the waveform which the pulse generator of the same 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 a state when the fixing | fixed part of the same nerve stimulation system is detained in the superior vena cava. It is a figure explaining the state which teared the sheath part of the same nerve stimulation system. It is a figure explaining the placement method of the conventional nerve stimulation system. It is a side view of the principal part in the nerve stimulation system of the modification of 1st Embodiment of this invention. It is sectional drawing of the side surface of the principal part in the same nerve stimulation system. It is sectional drawing of the principal part in the nerve stimulation system of the modification of 1st Embodiment of this invention. It is a side view of the principal part in the nerve stimulation system of 2nd Embodiment of this invention. It is a perspective view of the principal part of the nerve stimulation system. It is a perspective view of the principal part in the nerve stimulation system of the modification of 2nd Embodiment of this invention. It is sectional drawing of the principal part in the nerve stimulation system of 3rd Embodiment of this invention. It is sectional drawing of the principal part in the nerve stimulation system of 4th Embodiment 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.

(First embodiment)
Hereinafter, a first embodiment of a nerve stimulation system according to the present invention will be described with reference to FIGS. In all the drawings below, the thicknesses and dimensions of the components are adjusted 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 41. A lead part 40 attached to the fixing part 10, a sheath part 50 through which the lead part 40 is inserted, and an O-ring (sealing member, see FIG. 7) for sealing the space between the sheath part 50 and the lead part 40 ) 60 and a pulse generator 70 which is a stimulus supply device attached to the proximal end portion of the lead portion 40.

As shown in FIGS. 2 and 3, the fixing portion 10 has a plurality of urging portions 11 that are formed in a linear shape and connected to each other's distal end portions and to each other's proximal end portions. 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 (micrometer). Note that the coating 12 may not be provided on the wire.

The respective urging portions 11 are spaced apart from each other around the axis C of the lead portion 40 and are arranged around the axis C at equal angles (for example, every 90 ° if the number of the 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 20% Ag material or 35NLT 41% Ag material) having bending resistance is covered with an electrical insulating material (for example, ETFE or PTFE having a thickness of 20 μm). What was done can be used suitably.

The lead portion 40 is made of a tube formed of a biocompatible material (for example, polyurethane resin or polyamide resin). As shown in FIG. 1, the lead portion 40 includes the aforementioned distal end portion 41, a soft region 42 provided on the proximal end side with respect to the distal end portion 41, and a hard region provided on the proximal end side with respect to the soft region 42. 43.
The tip portion 41 and the soft region 42 have different hardness, and the tip portion 41 is harder than the soft region 42. The distal end portion 41 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 42 is a region of hardness that transmits only an elastic force large enough not to move the fixing unit 10 relative to the blood vessel even if it deforms.

The material forming the tip portion 41 may be metal or resin. When the tip portion 41 is formed of resin, the tip portion 41 is harder than the soft region 42.
Specifically, in accordance with JIS K7215, the Shore hardness (hereinafter abbreviated as “Shore hardness (D)”) measured using a type D durometer is determined by pushing operation (pushability) and rotation at the tip 41. 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 42 is 20 or more and 40 or less, and is sufficiently soft. The Shore hardness (D) of the soft region 42 is more preferably 30 or less.
For joining the tip portion 41 and the soft region 42, and the soft region 42 and the hard region 43, adhesion by a known adhesive, heat welding, ultrasonic welding, or the like can be selected as appropriate.

The outer diameter of the lead part 40 is, for example, about 2 mm, and the length in the axis C direction is about 500-800 mm. The length of the soft region 42 in the direction of the axis C is set to a length sufficient to absorb external force due to body movement or the like. When the nerve stimulation system 1 is implanted from the external jugular vein or the internal jugular vein, for example, about 50 to 200 mm, and when implanted from the subclavian vein, about 50 to 250 mm is suitable for the flexible region 42 depending on the insertion position. The length varies.
It has been confirmed that the external force can be absorbed at a minimum if the length of the flexible region 42 in the direction of the axis C is about 100 mm.
When the lead part 40 is hard over the entire length, external force due to patient movement such as body movement after indwelling is transmitted to the fixing part 10 installed at a desired position in the blood vessel, and the position of the fixing part 10 is moved. When the position shift occurs, the effect of stimulating the nerve may be reduced or lost.

As shown in FIG. 2, the base end portions of the plurality of biasing portions 11 are attached to the distal end portion 41 of the lead portion 40. As shown in FIGS. 3 and 4, the cross section perpendicular to the axis C of the tip 41 is formed in a square shape.
The distal end portion 41 is formed with a reduced diameter portion 41a by reducing the outer diameter on the proximal end side. The cross section orthogonal to the axis C of the reduced diameter portion 41a is square. An abutting surface 41b orthogonal to the axis C is formed at the tip of the reduced diameter portion 41a over the entire circumference.
A through hole 41c extending in the axis C direction is formed in the tip portion 41. A cross section perpendicular to the axis C of the through hole 41c is circular. The electrical wiring 14 is inserted through the through hole 41 c of the tip portion 41.
The reduced diameter portion 41a and the abutting surface 41b of the distal end portion 41 constitute an engaging portion 41e.
In FIG. 4, a later-described engaged portion 51 d of the sheath portion 50 that engages with the engaging portion 41 e of the lead portion 40 is indicated by a two-dot chain line.

As shown in FIGS. 4 and 5, a duct 42 a extending in the direction of the axis C is formed in the soft region 42. The electrical wiring 14 is inserted through the conduit 42 a in the flexible region 42. The distal end portion of the flexible region 42 is fixed to the distal end portion 41 with a known adhesive 45 while being inserted into the through hole 41 c of the distal end portion 41.
As shown in FIG. 6, a duct 43 a extending in the direction of the axis C is formed in the hard region 43. The electrical wiring 14 is inserted through the duct 43 a of the hard region 43.
In addition, you may provide antithrombogenicity and slidability by giving arbitrary coatings on the outer surface of the lead part 40. In order to increase the tensile strength of the lead portion 40, a tension member such as a metal wire may be inserted through the through hole 41c of the tip portion 41, the conduit 42a of the soft region 42, and the conduit 43a of the hard region 43.

As shown in FIGS. 1, 5, and 6, the sheath portion 50 includes a sheath distal end portion 51 that constitutes the distal end portion of the sheath portion 50, and a sheath main body portion 52 that is disposed on the proximal end side with respect to the sheath distal end portion 51. Have. The sheath body 52 includes a connection member 54 and a hub 55 disposed on the proximal end side with respect to the connection member 54.
As shown in FIGS. 1 and 5, the cross section perpendicular to the axis C of the distal end portion of the sheath distal end portion 51 is formed in a square edge shape. A cross section perpendicular to the axis C of the proximal end portion of the sheath distal end portion 51 is formed in a circular edge shape. The inner diameter of the distal end portion of the sheath distal end portion 51 is slightly larger than the outer diameter of the reduced diameter portion 41 a of the lead portion 40. On the outer peripheral surface of the sheath tip 51, a groove 51a extending in parallel with the axis C is formed over the entire length of the sheath tip 51. The groove 51 a is formed so as to be recessed from the outer peripheral surface of the sheath distal end 51 to the inner peripheral surface of the sheath distal end 51. More specifically, the groove 51a is formed such that the width (the length in the circumferential direction of the sheath 50) becomes narrower as it approaches the inner peripheral surface of the sheath tip 51. A pair of grooves 51a are formed on the sheath tip 51 with the axis C therebetween.

The inner peripheral surface 51 b of the distal end portion of the sheath distal end portion 51 is engaged (hooked) with the inner peripheral surface 51 b of the distal end portion of the sheath distal end portion 51, whereby the inner peripheral surface 51 b of the distal end portion of the sheath distal end portion 51 becomes the distal end portion 41. Can be engaged around the axis C. Since the cross-sectional shapes of the reduced diameter portion 41a of the distal end portion 41 and the distal end portion of the sheath distal end portion 51 are not circular, torque applied to the proximal end portion of the sheath portion 50 is transferred from the distal end portion of the sheath portion 50 to the fixed portion 10. I can tell you.
As shown in FIG. 4, the distal end surface 51 c of the sheath distal end portion 51 can be engaged with the abutting surface 41 b of the distal end portion 41 on the distal end side in the axis C direction. The engaged portion 51d is configured by the inner peripheral surface 51b and the distal end surface 51c of the distal end portion of the sheath distal end portion 51.

As shown in FIGS. 1 and 6, the cross section perpendicular to the axis C of the connection member 54 is formed in a circular edge shape. On the outer peripheral surface of the connecting member 54, a groove 54 a extending in parallel with the axis C is formed over the entire length of the connecting member 54. A pair of grooves 54 a are formed on the connecting member 54 with the axis C interposed therebetween.
The sheath tip 51 and the connection member 54 are integrally formed of a material having biocompatibility such as polyurethane resin, polyamide resin, fluororesin, for example. The groove 54 a of the connecting member 54 is continuous with the groove 51 a of the sheath distal end 51.

As shown in FIG. 7, a stepped portion 55 a is formed at the distal end portion of the outer peripheral surface of the hub 55 by reducing the outer diameter. As shown in FIG. 1, a groove 55 b extending in parallel with the axis C is formed on the outer peripheral surface of the hub 55 over the entire length of the outer peripheral surface of the hub 55. A pair of grooves 55b are formed on the hub 55 with the axis C interposed therebetween.
A base end portion of the connection member 54 is attached to the step portion 55a of the hub 55, and the hub 55 and the connection member 54 are joined by an adhesive (not shown) or the like. The groove portion 55 b of the hub 55 is continuous with the groove portion 54 a of the connection member 54. The groove 54 a of the connecting member 54 and the groove 55 b of the hub 55 are formed in the same manner as the groove 51 a of the sheath distal end 51. The groove 51a of the sheath tip 51, the groove 54a of the connecting member 54, and the groove 55b of the hub 55 constitute a sheath groove 50a. In this example, the sheath portion 50 is formed with a pair of sheath groove portions 50a.

The outer diameter of the sheath portion 50 is, for example, about 2.5 to 2.9 mm, the inner diameter is about 1.5 to 2.5 mm, and the length of the sheath portion 50 is about 300 mm. The shore hardness (D) of the sheath part 50 is set to a hardness sufficient for a rotational operation of, for example, about 55 to 70.
A metal blade using stainless steel or tungsten may be enclosed in the sheath portion 50 to improve the rigidity of the sheath portion 50 or improve kink resistance. In this case, a metal blade is disposed so as to avoid the sheath groove portion 50a, and the sheath portion 50 is pulled in the circumferential direction and split in the direction of the axis C as described later. The sheath 50 is preferably the same hardness as the hard region 43 or harder than the hard region 43.
The sheath portion 50 is disposed outside the lead portion 40 (so as to surround the lead portion 40), and is slidable in the axis C direction with respect to the lead portion 40.

  The hub 55 is desirably provided with a flow path for injecting physiological saline or the like via the sheath portion 50. In this case, a known luer lock connector is provided on the base end side of the flow path, and a syringe or the like can be attached to the luer lock connector. By operating the syringe, it is possible to release the chemical liquid stored in the syringe from the distal end of the sheath portion 50.

The O-ring 60 has a known configuration made of rubber or the like, and is provided on the inner peripheral surface of the hub 55 as shown in FIG. The inner diameter of the O-ring 60 is slightly smaller than the outer diameter of the hard region 43 of the lead portion 40. The lead portion 40 is inserted into the hole of the O-ring 60.
The lead portion 40 can move in the direction of the axis C with respect to the sheath portion 50 while being kept watertight with the O-ring 60. The O-ring 60 prevents blood backflow.

  The pulse generator 70 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 10 to 20 Hz (hertz) and a pulse width of 50 to 400 ms (seconds), a positive maximum current of 0.25 to 10 mA (ampere) to a negative maximum current of −0.25 to −10 mA. Among them, the one in which the current changes can be mentioned. The pulse generator 70 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.

The pulse generator 70 is connected to the pair of electrical wirings 14 and applies electrical stimulation between the pair of electrode portions 20. At this time, one of the pair of electrode portions 20 acts as a plus electrode, and the other acts as a minus electrode.
In this example, the lead part 40 cannot be removed from the pulse generator 70.

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.
First, the operator engages the engaged portion 51d of the sheath portion 50 with the engaging portion 41e of the lead portion 40 in the direction of the axis C and around the axis C as shown in FIG. 4 outside the body of the patient (living body). Step S10). More specifically, the engaged portion 51d is engaged with the engaging portion 41e on both sides around the axis C, and the engaged portion 51d is engaged with the engaging portion 41e on the distal end side. Since the lead part 40 is slidable in the hole of the O-ring 60, the sheath part 50 can be moved in the axis C direction and around the axis C with respect to the lead part 40.
As shown in FIG. 10, an opening is formed by making a small incision in the skin of a patient P near the neck (not shown). A known introducer or dilator (not shown) is installed in this opening, and the tip of the introducer is inserted into the internal jugular vein (blood vessel) P5.

Next, in a state where the engaged portion 41d of the sheath portion 50 is engaged with the engaging portion 41e of the lead portion 40, the fixing portion 10 and the lead portion 40 are placed in the internal jugular vein P5 through the installed introducer. Is inserted (step S12). 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 part 20 of the nerve stimulation system 1, the wire of the fixed part 10, and the electric wiring 14 are confirmed under fluoroscopy.
Since the space between the sheath portion 50 and the lead portion 40 is sealed by the O-ring 60, body fluid such as blood does not flow out of the body through the space between the sheath portion 50 and the lead portion 40.

  The operator operates the proximal end portion of the sheath portion 50 under X-ray fluoroscopy as necessary to push the proximal end portion of the sheath portion 50 or rotate it around the axis C (step S14). The sheath portion 50 and the distal end portion 41 are formed with a hardness that transmits an elastic force large enough to move the fixing portion 10 against the blood vessel against a frictional force acting between the blood vessel and the blood vessel. Therefore, by pushing the proximal end portion of the sheath portion 50, 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 50 about the axis C, the inner portion The fixed portion 10 rotates around the axis C with respect to the jugular vein P5.

As shown in FIG. 10, the fixing part 10 is roughly arranged in the superior vena cava (blood vessel) 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. That is, the fixing portion 10 elastically deformed toward the axis C side biases the inner surface of the superior vena cava P1.
Since the pair of electrode portions 20 are formed so as to be exposed on the opposite side of the urging portion 11 from the axis C, each electrode portion 20 faces the blood vessel wall P2 (see FIG. 2) side of the superior vena cava P1. The electrode portions 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. 10, a vagus nerve (nerve tissue) P6 is running adjacent to the superior vena cava P1.

Subsequently, the surgeon operates the pulse generator 70 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 50 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 50 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.
The position and orientation of the fixed part 10 with respect to the superior vena cava P1 are determined by the above procedure.

Next, the proximal end portion of the lead portion 40 is gripped to hold the position of the fixing portion 10 in the superior vena cava P1.
The proximal end portion of the sheath portion 50 is moved (retracted) with respect to the lead portion 40 to release the engagement between the engaging portion 41e of the lead portion 40 and the engaged portion 51d of the sheath portion 50. (Step S16). The distal end surface 51c of the sheath distal end portion 51 does not engage with the abutting surface 41b of the distal end portion 41 on the proximal end side in the axis C direction. For this reason, by pulling back the sheath portion 50 with respect to the lead portion 40, the engagement between the engaging portion 41e and the engaged portion 51d is easily released.
When the operation of pushing the lead part 40 is interwoven when the sheath part 50 is pulled back, the positional deviation of the fixing part 10 can be prevented and the position of the fixing part 10 can be reliably held.

After releasing the engagement between the engaging portion 41e and the engaged portion 51d, as shown in FIG. 11, the sheath main body portion 52 and the sheath distal end portion 51 are pulled in the circumferential direction from the proximal end side of the sheath groove portion 50a. By tearing in the C direction, a main body side cut 52a and a front end cut 51e are formed over the entire length of the sheath main body 52 and the sheath tip 51 in the longitudinal direction.
The main body side cut 52 a is formed from the outer peripheral surface to the inner peripheral surface of the sheath main body 52. The distal end cut 51 e is formed from the outer peripheral surface to the inner peripheral surface of the sheath distal end portion 51.
The lead part 40 is taken out of the sheath part 50 through the body-side cut 52a of the sheath part 50 and the tip-side cut 51e of the sheath tip part 51 (step S18). In this way, the sheath part 50 is peeled off.

The lead portion 40 is pushed in and fed into the blood vessel, and the lead portion 40 located in the blood vessel has a certain slack.
The slack of the lead part 40 may be an irregular shape, but may be a regular shape such as a spiral shape. The amount of slack (length) of the lead part 40 is preferably a length sufficient to absorb external force, for example, about 50 mm or more.
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 40 is moved by the patient's body movement, the flexible region 42 of the lead part 40 can transmit 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 when the force that acts on the lead portion 40 and is transmitted to the soft region 42 is further transmitted to the fixing portion 10, the movement of the pair of electrode portions 20 with respect to the superior vena cava P1 is suppressed. It is done.

When the above-described fixed period has elapsed, the pulse generator 70 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 removed from the small opening near the neck by pulling back the lead portion 40. Surgical reoperation is not required for removal of the system 1.
Thereafter, an appropriate treatment such as suturing the opening is performed, and the series of procedures is completed.

As described above, according to the nerve stimulation system 1 of the present embodiment, the engaging portion 41e of the lead portion 40 and the engaged portion 51d of the sheath portion 50 are engaged in the direction of the axis C and around the axis C. Thus, the force for operating the proximal end portion of the sheath portion 50 is transmitted to the fixed portion 10 via the sheath portion 50 and the distal end portion 41. That is, when the proximal end portion of the sheath portion 50 is pushed in, the fixing portion 10 is pushed into the blood vessel, and when the proximal end portion of the sheath portion 50 is rotated around the axis C, the fixing portion 10 rotates around the axis C in 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 41e and the engaged portion 51d is released. In this way, even when the lead part 40 is moved due to the body movement of the patient P, the pair of electrode parts with respect to the superior vena cava P1 is reduced in order to reduce the force transmitted to the flexible region 42 of the lead part 40. 20 can be prevented from moving.

  The sheath portion 50 can pull the sheath portion 50 in the circumferential direction from the sheath groove portion 50a and tear it in the axis C direction to form the main body side cut 52a and the tip side cut 51e over the entire length in the longitudinal direction of the sheath portion 50. Then, the lead portion 40 is taken out of the sheath portion 50 through the main body side cut 52a and the tip side cut 51e. Therefore, even when the lead part 40 cannot be removed from the pulse generator 70 when the nerve stimulation system 1 is placed, the sheath part 50 can be detached from the lead part 40 by tearing the sheath part 50. Thereby, the burden given to the patient P for the fixed period which continues applying an electrical stimulus to the vagus nerve P6 can be reduced.

Since the sheath part 50 is used to improve the operability of position adjustment of the fixed part 10, the rigidity of the sheath part 50 is set higher than the rigidity of the lead part 40. Therefore, when the distal end side of the sheath portion 50 shown in FIG. 12 is left in the patient P as a comparative example, the sheath portion 50 formed of a relatively hard material remains in the patient P, and it is difficult to make use of the flexibility of the lead portion 40. Become.
On the other hand, in the nerve stimulation system 1 of the present embodiment, the flexible flexible region 42 of the lead portion 40 is obtained without impairing the comfort of the patient by pulling the sheath portion 50 in the circumferential direction and tearing it in the direction of the axis C. The movement of the fixed portion 10 can be prevented by exposing the body movement of the patient P by exposing the body motion.
Thus, by using the sheath part 50 that can be engaged with and separated from the fixing part 10, the nerve stimulation system 1 that can be easily operated and placed in a flexible state is provided. Can do.

In the present embodiment, as in the nerve stimulation system 1A shown in FIGS. 13 and 14, a handle 72 protruding radially outward may be provided on the hub 71 of the sheath portion 50A. In this modification, a pair of handles 72 are formed so as to sandwich the hub 71.
The hub 71 has a larger outer diameter and inner diameter than the hub 55 of the present embodiment. The aforementioned groove portion 55 b is formed on the outer peripheral surface of the hub 71.
A notch 54 b extending from the outer peripheral surface of the connecting member 54 to the inner peripheral surface is formed on the base end surface of the connecting member 54. In the connecting member 54, the notch 54b is continuous with the groove 54a.
According to the nerve stimulation system 1A configured as described above, the hub 71 is easily torn by gripping the pair of handles 72 and tearing the hub 71 from the groove portion 55b. When the hub 71 is torn, the connection member 54 is torn from the notch 54b and the groove 54a by the torn hub 71.

  In the nerve stimulation system 1 of the present embodiment, the sheath groove portion 50a may not be formed in the sheath portion 50. In this case, in the indwelling method of the present nerve stimulation system 1, the entire sheath portion 50 is taken out from the patient P as shown in FIG.

Further, since the sheath 50 is formed with a sheath groove 50a that is recessed from the outer peripheral surface of the sheath 50 to the inner peripheral surface of the sheath 50, the sheath 50 is pulled in the circumferential direction. It was assumed that the main body side cut could be formed in the sheath portion 50 by tearing in the direction. However, a notch such as the notch 54b in the connecting member 54 described above is formed on the proximal end surface of the sheath main body 52 from the outer peripheral surface to the inner peripheral surface of the sheath main body 52, and the sheath starts from this notch. The main body 52 may be pulled in the circumferential direction and split in the axis C direction to form a main body-side cut in the sheath main body 52.
Although the main body side cut 52a is formed over the entire length of the sheath main body 52 in the longitudinal direction, the main body side cut 52a may be formed in at least a part of the sheath main body 52 in the longitudinal direction.

The cross-sectional shape of the reduced diameter portion 41a of the distal end portion 41 and the distal end portion of the sheath distal end portion 51 is assumed to be a square edge. However, these cross-sectional shapes may be elliptical or polygonal edge shapes.
Alternatively, a method may be used in which a notch is provided at the distal end of the sheath portion and the distal end portion of the sheath portion and the distal end portion 41 of the lead portion 40 are engaged to transmit torque around the axis C.
Although a pair of sheath groove portions 50a are formed in the sheath portion 50, the number of the sheath groove portions 50a formed in the sheath portion 50 is not particularly limited, and may be one or three or more.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. 16 to 18. However, the same parts as those of the above-described embodiment are denoted by the same reference numerals, the description thereof will be omitted, and only different points will be described. explain.
As shown in FIGS. 16 and 17, the sheath portion 80 provided in the nerve stimulation system 2 of the present embodiment includes a sheath tip portion 81 instead of the sheath tip portion 51 of the sheath portion 50 of the first embodiment.
The sheath distal end portion 81 is configured by disposing engagement pieces 82 and 83 formed in a U shape when viewed in the direction of the axis C so that the concave portions thereof face each other. The engagement pieces 82 and 83 are made of a metal or resin material that is harder than the connection member 54. The engaged portions 81a are configured by the tip surfaces 82a, 83a and the inner peripheral surfaces 82b, 83b of the engaging pieces 82, 83. The sheath distal end portion 81 and the connection member 54 are joined by adhesion, integral molding, or the like.

  By configuring the sheath distal end portion 81 in this manner, a large torque can be transmitted to the distal end portion 41 of the lead portion 40. Further, the gap between the engagement piece 82 and the engagement piece 83 becomes a cut 81b, and when the sheath main body 52 of the sheath portion 80 is torn, the sheath tip 81 is separated into the engagement piece 82 and the engagement piece 83. can do.

As shown in FIG. 18, in this embodiment, the sheath portion 80 </ b> A may be configured to have a sheath distal end portion 86 instead of the sheath distal end portion 81. The sheath distal end portion 86 is formed in a square edge shape in a cross section orthogonal to the axis C. The sheath distal end portion 86 can be formed of the same material as the engagement pieces 82 and 83. The sheath tip 86 cannot be split in the direction of the axis C.
The thus configured sheath portion 80A takes out the entire sheath portion 80A from the inside of the blood vessel, tears the sheath body portion 52, and separates the sheath body portion 52 from the sheath distal end portion 86. At this time, the sheath distal end portion 86 cannot be torn and the sheath distal end portion 86 cannot be removed from the lead portion 40. However, since the length of the sheath distal end portion 86 in the axis C direction is short, even if the sheath distal end portion 86 goes out of the body, the flexibility of the lead portion 40 is not impaired.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. 19, 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. 19, the nerve stimulation system 3 of the present embodiment has a lead portion holding mechanism 96 instead of the hub 55 of the sheath portion 50 of the first embodiment. The connecting member 54 and the lead portion holding mechanism 96 constitute the sheath main body 91, and the sheath tip portion 51 and the sheath main body 91 (not shown) constitute the sheath portion 90. That is, the lead portion holding mechanism 96 is disposed on the proximal end side of the sheath main body portion 91.

The lead portion holding mechanism 96 has a main body 97 formed in a tubular shape. A recess 97 a for holding the O-ring 60 is formed on the inner peripheral surface of the main body 97.
Side holes 97b and 97c communicating with the conduit of the main body 97 are formed on the front end side and the base end side of the main body 97 with respect to the recess 97a. A female screw portion (not shown) is formed in the side hole 97c. A receiving portion 97 d that protrudes from the inner peripheral surface of the main body 97 toward the side hole 97 c is provided at a position facing the side hole 97 c on the inner peripheral surface of the main body 97.
On the outer peripheral surface of the main body 97, a groove 97f extending in parallel with the axis C is formed over the entire length of the outer peripheral surface of the main body 97. The groove 97 f of the main body 97 is continuous with the groove 54 a of the connection member 54.
The main body 97 can be formed of ABS (acrylonitrile / butadiene / styrene resin) or PC (polycarbonate resin resin).
The main body 97 is fixed to the connection member 54 with an adhesive or the like.

A tube 99 is connected to the side hole 97b. Although not shown, the tube 99 is connected to a syringe containing a chemical solution such as heparin.
The screw member 100 is screwed into the female screw portion of the side hole 97c. By increasing the length with which the screw member 100 is screwed into the female screw portion, the lead portion 40 inserted through the conduit of the main body 97 is sandwiched between the tip of the screw member 100 and the receiving portion 97d. Thereby, the lead portion holding mechanism 96 holds the position of the lead portion 40 with respect to the main body 97 in the axis C direction.
The holding of the lead part 40 is released by shortening the length in which the screw member 100 is screwed into the female screw part (releasing the screw member 100).

  In the state where the engaging portion 41e of the lead portion 40 and the engaged portion 51d of the sheath portion 90 are engaged, the lead portion 40 is held by the lead portion holding mechanism 96, so that the engaged portion 41e is engaged. The part 51d will not come off unintentionally. Thereby, the surgeon can operate the fixing portion 10 by pushing or pulling back the lead portion holding mechanism 96.

  When tearing the sheath portion 90 in the direction of the axis C, the screw member 100 is loosened and the sheath portion 90 is pulled back. The main body 97 is split from the groove 97f in the axis C direction to form a holding-side cut 97g over the entire length of the main body 97 in the longitudinal direction. Then, the lead part 40 is taken out of the lead part holding mechanism 96 through the holding side cut 97g.

(Fourth embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. 20, but the same parts as those of the above embodiment will be denoted by the same reference numerals and the description thereof will be omitted, and only different points will be described.
As shown in FIG. 20, the nerve stimulation system 4 of the present embodiment has a sealing force adjusting mechanism 116 instead of the hub 55 of the sheath portion 50 of the first embodiment. The connecting member 54 and the sealing force adjusting mechanism 116 constitute the sheath main body 111, and the sheath tip part 51 and the sheath main body 111 (not shown) constitute the sheath part 110. That is, the sealing force adjusting mechanism 116 is disposed on the proximal end side of the sheath main body 111.

The sealing force adjusting mechanism 116 has a main body 117 formed in a tubular shape. The base end portion of the main body 97 has a large-diameter portion 117a formed by expanding the inner diameter. The front end side of the main body 117 is a small-diameter portion 117b having an inner diameter smaller than that of the large-diameter portion 117a.
A stepped portion 117c is formed between the small diameter portion 117b and the large diameter portion 117a, and a female screw portion (not shown) is formed at the base end portion of the large diameter portion 117a.
A side hole 117d that communicates with a pipe line of the main body 117 is formed on the front end side of the stepped portion 117c in the main body 117.
On the outer peripheral surface of the main body 117, a groove portion 117f extending in parallel with the axis C is formed over the entire length of the outer peripheral surface of the main body 117. The groove 117 f of the main body 117 is continuous with the groove 54 a of the connection member 54.
The main body 117 can be formed of the same material as the main body 97.

The aforementioned tube 99 is connected to the side hole 117d.
The O-ring 60 is disposed on the stepped portion 117c. The male screw portion 119a formed on the outer peripheral surface of the cylindrical pressing member 119 is screwed into the female screw portion of the large diameter portion 117a. A flange 119b is provided at the proximal end portion of the pressing member 119. By gripping the flange 119b, the pressing member 119 can be easily operated.
The lead part 40 is inserted into the O-ring 60 and the pressing member 119.

  In the nerve stimulation system 4 configured as described above, the O-ring 60 is crushed in the direction of the axis C by increasing the length that the pressing member 119 is screwed into the female screw portion (tightening the pressing member 119). The force acting between the lead part 40 and the O-ring 60 increases. On the other hand, the O-ring 60 spreads in the direction of the axis C and acts between the lead portion 40 and the O-ring 60 by shortening the length that the pressing member 119 is screwed into the female screw portion (releasing the pressing member 119). The power to do is reduced.

The pressing member 119 is tightened in a state where the engaging portion 41e of the lead portion 40 and the engaged portion 51d of the sheath portion 90 are engaged, so that the engaged portion 51d is not detached from the engaging portion 41e.
When releasing the engagement between the engaging portion 41e and the engaged portion 51d, the O-ring 60 is easily moved in the direction of the axis C with respect to the lead portion 40 by loosening the pressing member 119.
Since the tightening force of the lead part 40 by the O-ring 60 can be changed, the moving operation of the sheath part 110 on the lead part 40 can be operated with less resistance.

  When tearing the sheath part 110 in the direction of the axis C, the pressing member 119 is loosened and the sheath part 110 is pulled back. The main body 117 is split from the groove 117f in the direction of the axis C to form a sealing-side cut 117g over the entire length of the main body 117 in the longitudinal direction. Then, the lead portion 40 is taken out of the sealing force adjusting mechanism 116 through the sealing side cut 117g.

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. are also included. Furthermore, it goes without saying that the configurations shown in the embodiments can be used in appropriate combinations.
For example, in the first to fourth embodiments, the configuration of the fixing unit 10 can be variously modified as described below.

21 has a rod-like support member 131 extending from the tip end portion 41 toward the tip end side, 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 addition to the components of the fixing unit 10 of the first embodiment, the fixing unit 160 shown in FIG. 24 is provided with a needle portion 161 that protrudes toward the tip side on the tip side of each biasing portion 11, and each attachment. A needle portion 162 protruding toward the proximal end side is provided on the proximal end side of the biasing portion 11. In the fixing part 160 configured as described above, the fixing part 160 can be positioned in the superior vena cava P1 by puncturing the blood vessel wall P2 with the needle parts 161 and 162.

  In addition, by providing a groove or a protrusion on a wire (not shown) of these fixing portions 130, 140, 150, and 160, it is possible to increase the fixing force of the fixing portion and prevent the fixing portion from moving.

In the embodiment, the engaging portion may be provided in the fixed portion 10 by using the uneven shape of the base end portions of the plurality of biasing portions 11. In this case, the tip of the lead portion may have the same hardness as the soft region 42. Further, the engaging portion may be provided at both the tip portion 41 and the fixing portion 10 of the lead portion 40.
A connector for detachably connecting to the pulse generator 70 may be provided at the proximal end portion of the rigid region 43 of the lead portion 40. For this connector, for example, a known IS-1 connector or other waterproof connector may be used. In this case, when a connector is connected to the pulse generator 70, an electrical stimulus is generated between the electrode portions 20 via the pair of electric wires 14.

The fixing unit 10 may be configured to include three or more electrode units 20.
In the embodiment, the lead part 40 has the tip part 41, the soft region 42, and the hard region 43, and is formed of two kinds of materials having different hardnesses. However, all the lead portions may be formed of the same material as that of the soft region, or the lead portions may be formed of three or more kinds of materials having different hardnesses.
The pair of electrode portions 20 may be provided in different biasing portions 11.
The nerve stimulation system of this embodiment can also be used for a cardiac pacing lead, for example.

Furthermore, the present invention includes the following technical ideas.
(Additional item 1)
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;
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 portion provided on the portion, and transmits only an elastic force of a size that does not move the fixing portion relative to the blood vessel even if it deforms to the proximal end side of the lead portion with respect to the distal end portion of the lead portion. A neurostimulation system indwelling method in which a nerve stimulation system provided with a soft region that is not placed in a living body,
Engaging the engaged portion of the sheath portion with the engaging portion;
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,
Pull back the sheath portion to release the engagement between the engagement portion and the engaged portion of the sheath portion,
An indwelling method of a nerve stimulation system for taking out the entire sheath part from the living body.

1, 1A, 2, 3, 4 Neural stimulation system 10, 130, 140, 150, 160 Fixing part 20 Electrode part 40 Lead part 41 Tip part 41e Engaging part 42 Soft region 50, 50A, 80, 80A, 90, 110 Sheath portion 51, 81, 86 Sheath tip portion 51d Engaged portion 51e Tip side cut 52, 91, 111 Sheath body portion 52a Body side cut 60 O-ring (sealing member)
96 Lead part holding mechanism 97g Holding side cut 116 Sealing force adjusting mechanism 117g Sealing side cut C axis P1 superior vena cava (blood vessel)
P5 Internal jugular vein (blood vessel)

Claims (4)

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
On the proximal end side of the distal end portion of the lead portion, there is provided a soft region that transmits only an elastic force of a size that does not move the fixing portion relative to the blood vessel even if it deforms,
The sheath portion is
A sheath distal end portion that constitutes a distal end portion of the sheath portion, and the engaged portion is provided;
A sheath body disposed on the proximal side of the sheath tip,
Have
The sheath main body portion is formed by pulling the sheath main body portion in the circumferential direction and tearing the sheath main body portion in the axial direction to form a main body side cut in at least a part of the longitudinal direction of the sheath main body portion. A nerve stimulation system characterized in that the lead part can be taken out of the main body part.   The sheath distal end portion is formed by pulling the sheath distal end portion in the circumferential direction and tearing the sheath distal end portion in the axial direction to form a distal end cut across the entire length in the longitudinal direction of the sheath distal end portion. The nerve stimulation system according to claim 1, wherein the lead portion can be taken out from the outside. The sheath portion is
Formed in a tubular shape and disposed on the proximal end side of the sheath main body portion, and having a lead portion holding mechanism capable of releasing the holding while holding the lead portion in the axial direction;
The lead part holding mechanism pulls the lead part holding mechanism in the circumferential direction, tears it in the axial direction, and forms a holding side cut over the entire length in the longitudinal direction of the lead part holding mechanism, thereby allowing the lead side holding mechanism to pass through the holding side cut. The nerve stimulation system according to claim 1, wherein the lead part can be taken out of the lead part holding mechanism. The sheath portion is
A sealing force adjusting mechanism that is formed in a tubular shape and disposed on the proximal end side of the sheath main body, and that can adjust the force acting between the lead portion and the sealing member;
The sealing force adjusting mechanism pulls the sealing force adjusting mechanism in the circumferential direction and tears it in the axial direction to form a sealing-side cut across the entire length in the longitudinal direction of the sealing force adjusting mechanism. The nerve stimulation system according to claim 1, wherein the lead portion can be taken out of the sealing force adjusting mechanism through a stop side cut.

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