Catheter and intravascular device

Abstract

Provided are a catheter and an intravascular device capable of freely entering even a thin blood vessel into which a stent cannot enter, and detecting or stimulating nerve tissue activity with high sensitivity and from a more free position.　A catheter 10 which is positioned in a blood vessel of the brain of an organism and comprises an electrode 11 for detecting or stimulating activity of nerve tissue located outside the blood vessel, said catheter 10 comprising: at least one electrode 11 provided at a tip portion inserted into the blood vessel; and a lead wire 13 provided for each electrode 11 and having one end thereof electrically connected to said electrode 11.

Description

Catheter, intravascular device

[0001] The present invention relates to a catheter and an intravascular device for use in detecting or stimulating nerve tissue activity.

[0002] Conventionally, in surgeries for intractable epilepsy (epilepsy in which drug-induced alleviation of seizure symptoms is not observed) and the like, surgery to surgically resect a part of brain tissue has been performed. Various methods have been adopted for identifying the resection site, but each has many problems. For example, the method of measuring brain waves by attaching electrodes to the scalp is non-invasive and can be implemented in many facilities. However, this method has low spatial resolution and temporal resolution, and there is a risk that the site to be resected cannot be correctly identified.

[0003] Furthermore, for example, the technique of measuring brain waves by attaching subdural electrodes or inserting deep brain electrodes after craniotomy has high spatial resolution and temporal resolution, but it is extremely highly invasive, and causes complications caused by the intracranial electrodes as described above. In addition, depending on the state of the brain surface, the above-mentioned intracranial electrodes cannot be left in place for a long time of several days or more, and since there are few specialists in neurosurgery, the facilities where the procedure can be performed are limited, which have also been problems.

[0004] Patent Document 1 discloses a device used for detecting or stimulating nerve tissue activity. In Patent Document 1, a stent provided with electrodes is expanded in a cerebral blood vessel and locked to the vessel wall, thereby sensing or stimulating the electrical activity of nearby nerve tissue.

[0005] Japanese Unexamined Patent Publication No. 2017-159079

[0006] However, the method of Patent Document 1 uses a stent having an expansion force. Due to the rigidity of the stent and the bulk of the stent and electrodes, the method of Patent Document 1 is limited to thick and robust blood vessels that can be accessed. In addition, in the method of Patent Document 1, since electrodes are only provided on the stent portion, the regions where detection and stimulation can be performed are limited. For these reasons, the method of Patent Document 1 has a problem that detailed detection and stimulation cannot be performed.

[0007] The object of the present invention is to provide a catheter and intravascular device that can freely enter even narrow blood vessels into which stents cannot enter, and that can detect or stimulate nerve tissue activity with high sensitivity and at a more flexible location.

[0008] The present invention solves the above problem by the following means.

[0009] (1) The present invention relates to a catheter that is placed in a blood vessel of the brain of a living organism and is equipped with electrodes for detecting or stimulating the activity of nerve tissue located outside the blood vessel, the catheter comprising at least one electrode provided at the tip portion that is inserted into the blood vessel, and a conductor provided for each electrode, with one end electrically connected to the electrode.

[0010] (2) Preferably, the catheter is formed by stacking multiple layers radially to form a single unit, the conductor is arranged in one of the layers between the multiple layers so as to extend toward the proximal end of the catheter, and the conductor is insulated from two adjacent layers.

[0011] (3) Furthermore, it is preferable that the electrical resistance between the electrode and the other end of the conductor of the catheter is 100 Ω or less.

[0012] (4) The present invention relates to an intravascular device comprising a catheter according to any of (1) to (3) above, and a wire member that is insertable into the lumen of the catheter and has at least one wire-side electrode at its tip, wherein the wire member is inserted into the lumen of the catheter and protrudes from the tip of the catheter within the blood vessel, and the wire-side electrode is located at a position further away from the electrode, and the wire-side electrode and the electrode together detect or stimulate the activity of nerve tissue located outside the blood vessel.

[0013] (5) The intravascular device also comprises a first hemostatic structure having a valve connected to one end of a sheath located outside the blood vessel for inserting the intravascular device into a blood vessel of the living body, and having a valve that holds the catheter by making the space between the catheter and the sheath liquid-tight, wherein the valve has an elastically deformable cylindrical member, and the cylindrical member holds the catheter by being compressed when the catheter is passed through the cylindrical member.

[0014] (6) The intravascular device also preferably includes a second hemostatic structure connected to the proximal end of the catheter and having a valve that holds the wire member in a liquid-tight manner, wherein the valve has an elastically deformable cylindrical member, and the cylindrical member holds the wire member by being compressed while the wire member is passed through the cylindrical member.

[0015] (7) Furthermore, it is preferable that the electrode and the wire-side electrode of the intravascular device remain in the blood vessel for one day or more.

[0016] (8) Furthermore, it is preferable that the blood vessel in which the electrodes and wire-side electrodes of the intravascular device are placed is a cerebral vein.

[0017] (9) The present invention relates to a flexible catheter having at least one electrode provided at one end, and a conductor provided for each electrode, with one end electrically connected to the electrode, wherein the electrical resistance between the electrode and the other end of the conductor is 100 Ω or less.

[0018] (10) It is also preferable that the one end of the catheter on which the electrode is attached is left in the blood vessel for one day or more.

[0019] (11) Furthermore, it is preferable that the blood vessel to which the one end of the catheter on which the electrode is provided is located is a cerebral vein.

[0020] (12) The present invention relates to an intravascular device comprising any of the catheters described in (9) to (11) above, wherein one end is positioned within a blood vessel of the brain of a living organism and is used to detect or stimulate the activity of nerve tissue located outside the blood vessel.

[0021] (13) The intravascular device also comprises a first hemostatic structure having a valve connected to one end of a sheath located outside the blood vessel for inserting the intravascular device into the blood vessel, and which holds the catheter by making the space between the catheter and the sheath liquid-tight, wherein the valve has an elastically deformable cylindrical member, and the cylindrical member holds the catheter by being compressed when the catheter is passed through the cylindrical member.

[0022] (14) It is also preferable that the intravascular device is connected to the other end of the catheter that is located outside the blood vessel and opposite to the one end in the longitudinal direction of the catheter, and that the other end is closed off.

[0023] According to the present invention, it is possible to provide a catheter and intravascular device that can freely enter even narrow blood vessels into which stents cannot enter, and that can detect or stimulate nerve tissue activity with high sensitivity and at a more flexible location.

[0024] This is a diagram illustrating the intravascular device 1 of the first embodiment. This is a diagram illustrating the catheter 10 of the first embodiment. This is a schematic diagram showing a longitudinal section of the tip of the catheter 10. This is a diagram showing the intravascular device 1 of the first embodiment with valves 30 and 50 attached. This is a diagram illustrating valve 30. This is a diagram illustrating valve 50. This is a diagram illustrating the structure of valves 30 and 50. This is a diagram showing an example of the intravascular device 1 placed in a cerebral blood vessel multiple wire members 20 being passed through valve 30. This is a diagram illustrating the intravascular device 2 of the second embodiment. This is a diagram illustrating the intravascular device 3 of the third embodiment.

[0025] Embodiments of the present invention will be described below with reference to the drawings and other figures. Note that the following figures, including Figure 1, are schematic representations, and the size and shape of each part have been exaggerated as appropriate for ease of understanding. Furthermore, the numerical values ​​such as dimensions and material names of each component described herein are merely examples of embodiments and are not limiting; they may be selected and used as appropriate.

[0026] (First Embodiment) Figure 1 is a diagram illustrating the intravascular device 1 of the first embodiment. Figure 2 is a diagram illustrating the catheter 10 of the first embodiment. Figure 2 shows the tip portion of the catheter 10. The intravascular device 1 is used to detect or stimulate the activity of nerve tissue in living organisms such as animals or humans, and is placed inside the blood vessels of the organism (typically cerebral blood vessels) and is equipped with multiple electrodes for detecting or stimulating the activity of nerve tissue located outside the blood vessels in the vicinity. The intravascular device 1 is electrically connected to a calculation unit such as a measuring device (not shown), and transmits potential information obtained from the electrodes to the calculation unit, or generates a predetermined potential difference upon instruction from the calculation unit. The intravascular device 1 is also left inside the blood vessel for a predetermined period of time to detect or stimulate the activity of nerve tissue. The predetermined period is one hour or more (specifically, two hours or more, one day or more, two days or more, five days or more, seven days or more, two weeks or more, or one month or more). In this embodiment, the intravascular device 1 has a tip end on the side that is inserted into a blood vessel in the body, and a proximal end on the opposite side in the longitudinal direction.

[0027] The intravascular device 1 of this embodiment comprises a catheter 10 and at least one wire member 20 inserted into the catheter 10. The catheter 10 and the wire member 20 are equipped with electrodes 11 and 21 at their tip ends, respectively. For ease of understanding, Figure 1 shows an example in which the intravascular device 1 has one wire member 20, but it is not limited to this and may have two or more.

[0028] The catheter 10 is a flexible, tubular member. The catheter 10 allows for the insertion of at least one wire member 20 into its lumen, and the inserted wire member 20 can be freely moved in and out. The catheter 10 also has at least one electrode 11 at its tip. In this embodiment, the catheter 10 is described using an example where it has five electrodes 11, as shown in Figures 1 and 2, but the number of electrodes 11 is not limited to this. The catheter 10 is inserted into a blood vessel and left in place for a predetermined period. Therefore, it is preferable that the catheter 10 has good lubricity for easy movement within the blood vessel, as well as mechanical strength, flexibility, and biocompatibility.

[0029] Figure 3 is a schematic diagram showing a longitudinal cross-section of the tip of the catheter 10. In Figure 3, for ease of understanding, only two electrodes 21 provided at the tip of the catheter 10 are shown. The catheter 10 is formed by laminating and integrating multiple layers in its radial direction. In this embodiment, the catheter 10 has, in order from the innermost layer to the outermost layer, a first layer 121, a second layer 122, and a third layer 123 in the radial direction. In Figure 3, for explanatory purposes, the second layer 122 and the third layer 123 are shown to be spaced apart in the radial direction, but in reality, each layer is laminated and integrated. The catheter 10 has an outer diameter of 0.60 to 1 mm and an inner diameter (diameter of the lumen) of 0.28 to 0.55 mm. In this embodiment, the catheter 10 has an outer diameter of 0.75 mm and an inner diameter of 0.4 mm.

[0030] The first layer 121 is a resin layer located on the innermost side of the catheter 10. In this embodiment, the first layer 121 is made of polytetrafluoroethylene (PTFE), but it is not limited to this and may be made of polyamide or a fluororesin. This first layer 121 is provided to improve the sliding of the wire member 20 as it moves inside the catheter 10. The first layer 121 has a thickness of 0.05 to 0.5 mm, and in this embodiment, its thickness is 0.2 mm.

[0031] The second layer 122 is a layer located on the outer diameter side of the first layer 121 and is formed from wire made of stainless steel or the like. The second layer 122 is formed using the first layer 121 as a base material, by winding wire in a coil shape at predetermined intervals around the outer surface of the first layer 121, or by arranging multiple wires in a mesh shape. That is, the second layer 122 may be in a form in which wire is wound in a coil shape around the outer surface of the first layer 121 at predetermined intervals (coil shape), or in a form in which multiple wires are arranged in a mesh shape around the outer surface of the second layer 122 (blade shape). Furthermore, the second layer 122 may be in a form that switches from a coil shape to a blade shape, or from a blade shape to a coil shape, in the longitudinal direction of the catheter 10. In addition, the outer surface of the wire forming the second layer 122 may be coated with an insulating resin. By incorporating this second layer 122, the catheter 10 achieves sufficient torque and flexibility, making it easier to push into the blood vessel.

[0032] In this embodiment, the second layer 122 is a blade-like structure in which 16 wires with a diameter of 0.05 mm are arranged in a mesh pattern, and the PPI (pitch per inch) is 60. However, the number of wires may be 32, the wire diameter may be 0.02 to 0.1 mm, and the PPI may be 40 to 300.

[0033] The third layer 123 is located on the outer diameter side of the second layer 122 and is the outermost layer of the catheter 10. The third layer 123 is a resin layer, and in this embodiment it is formed of polyether block amide (PEBAX). The third layer 123 is not limited to this, and is preferably formed using a resin that has good lubricity, mechanical strength, flexibility and biocompatibility, and can be formed using fluororesins, nylon resins, etc.

[0034] The third layer 123 is formed such that its hardness gradually increases from the tip end to the proximal end of the catheter 10. This configuration makes it easy to push the catheter 10 in and out. In this embodiment, the third layer 123 is molded from PEBAX resin, for example, with different hardness levels in the tip, middle, and proximal portions along the longitudinal direction of the catheter 10, with the tip having the lowest hardness and the middle and proximal portions having the highest hardness. The thickness of the third layer 123 can be 0.05 to 0.8 mm, and in this embodiment, the thickness is 0.15 mm.

[0035] At least one electrode 11 is provided at the tip of the catheter 10. If multiple electrodes 11 are provided, they are arranged at predetermined intervals along the longitudinal direction of the catheter 10. The electrode 11 is a ring-shaped platinum alloy component. In this embodiment, the electrode 11 is described as being provided at the tip of the catheter 10, but it is not limited to this, and the electrode 11 may be provided a few centimeters from the tip towards the base end, or more than ten centimeters from the base end, or at any other location along the longitudinal direction of the catheter 10. In order to properly detect and transmit current, the electrode 11 preferably has a width W1 (the longitudinal dimension of the catheter 10) of 1 mm or more, and preferably 2 to 5 mm. In this embodiment, the width W1 of the electrode 11 is 2 mm.

[0036] Furthermore, from the viewpoint of achieving highly sensitive detection and stimulation, it is preferable that the spacing W2 of the electrodes 11 on the catheter 10 be 5 to 30 mm. In this embodiment, the spacing W2 is 10 mm. Also, the electrode 11 located closest to the tip of the catheter 10 is located proximal to the tip of the catheter 10 by a distance W3. In this embodiment, the distance W3 is 3 mm.

[0037] Note that in Figure 3, for ease of understanding, the outer diameter of the electrode 11 is shown to be larger than the outer diameter of the third layer 123. However, in reality, the main body of the catheter 10 and the electrode 11 are fitted together by hammering or other means, and the electrode 11 is formed in such a way that no steps or other unevenness occur.

[0038] Each electrode 11 is connected to a calculation unit of a measuring device or the like (not shown) by a conductor 13. The tip of the conductor 13 is connected to the inner circumferential surface of the electrode 11, and it is arranged to extend from the electrode 11 of the third layer 123 to the proximal end side along the outer circumferential surface of the second layer 122, passing through a hole (not shown) provided at the position where the electrodes 11 of the third layer 123 are stacked. Therefore, the conductor 13 is located between the layers of the second layer 122 and the third layer 123. The conductor 13 may be wrapped around the outer circumferential surface of the second layer 122 several times (for example, once or twice) as appropriate. The proximal end portion of the conductor 13 extends to the outside from a hole (not shown) provided in the third layer 123 at the proximal end of the catheter 10 and is electrically connected to a calculation unit (not shown). One conductor 13 is connected to each electrode 11, and the number of conductors 13 corresponding to the number of electrodes 11 extend from the proximal end side of the catheter 10 to the outside.

[0039] In this embodiment, the conductor 13 is made of SUS304, but is not limited to this; it may also be made of cobalt alloy, molybdenum alloy, copper, or copper alloy. The outer surface of the conductor 13 is coated with an insulating resin and is insulated from the second layer 122 and the third layer 123. The outer diameter of the conductor 13 can be 0.01 to 0.1 mm, and in this embodiment, it is 0.05 mm.

[0040] In order to properly detect electric current from extravascular tissue or to properly transmit electric current to extravascular tissue, the catheter 10 preferably has an electrical resistance value of 100 Ω or less between the electrode 11 and the proximal (posterior) end of the corresponding conductor 13, and more preferably 75 Ω or less.

[0041] Generally, the electrical resistance between the electrode 11 and the base end of the conductor 13 increases in proportion to the length of the conductor 13. Therefore, for example, if the electrode 11 and the calculation unit are electrically connected using a wire that forms the second layer 122, or if the conductor 13 is wound around the second layer 122 in a coil shape, the electrical resistance between the electrode 11 and the base end of the conductor 13 will also increase. However, in this embodiment, the conductor 13 is arranged along the longitudinal direction on the outer surface of the second layer 122 and is wound around the second layer 122 only a few times, so the length of the conductor 13 does not increase, and the electrical resistance between the electrode 11 and the base end of the conductor 13 can be sufficiently suppressed. Therefore, the catheter 10 of this embodiment can satisfy the above conditions.

[0042] The wire member 20 is a flexible linear (or string-like, rod-like) member, and an electrode 21, which is the wire-side electrode, is provided at its tip. Unlike a cylindrical body, the wire member 20 does not have a lumen (hollow part). The wire member 20 is also conductive, and its base end is electrically connected to a calculation unit of a measuring device or the like (not shown). The wire member 20 is a straight wire, but is not limited to this; for example, a stranded wire, a coil, or a multi-strand coil may be used. Furthermore, the wire member 20 can be made of, for example, stainless steel or an alloy of Ni (nickel) and Ti (titanium).

[0043] Furthermore, the wire member 20 has an insulating coating formed on its surface. In this embodiment, the insulating coating is formed by, for example, a PTFE (polytetrafluoroethylene) coating. However, it is not limited to this, and the insulating coating may also be formed by heat shrinking a tubular member made of polyimide, silicone, PTFE, etc. In this embodiment, as an example, the wire member 20 is a straight wire made of an alloy of Ni (nickel) and Ti (titanium), with an insulating coating of PTFE formed on its surface, and an outer diameter of 0.28 mm will be described.

[0044] The electrode 21 is, for example, in the form of a close contact coil, and is provided at the distal end of the wire member 20 in electrical connection with the wire member 20. By forming the electrode 21 into the above-described close contact coil shape, the electrode 21 has flexibility, which can improve deliverability to blood vessels and reduce the risk of damaging blood vessels. Such a coiled electrode 21 can be formed, for example, by spirally winding a metal wire of an alloy of Pt (platinum) and W (tungsten) to form a close contact coil. By using an alloy containing Pt (platinum) for the electrode 21, the visibility of the electrode 21 when observed under X-ray can be improved.

[0045] The outer diameter of the electrode 21 can be, for example, 0.1 mm or more and 0.28 mm or less. The outer diameter of the electrode 21 in the present embodiment is 0.25 mm. Note that, in the present embodiment, as an example, a configuration in which the outer diameter of the electrode 21 is smaller than the outer diameter of the wire member 20 is shown, but the present invention is not limited thereto, and the outer diameter of the electrode 21 may be the same as the outer diameter of the wire member 20. In addition, in order to appropriately detect or transmit current, the length (dimension in the longitudinal direction) of the electrode 21 is preferably 1 mm or more, and more preferably 2 mm or more. The length of the electrode 21 in the present embodiment is 3 mm. Note that the electrode 21 may be formed such that the distal end portion thereof has a smaller outer diameter than other portions of the electrode 21. By forming the electrode 21 in such a shape, deliverability to blood vessels can be improved. In the present embodiment, as shown in FIG. 1, the distal end portion of the electrode 21 is formed to have a smaller outer diameter than the body portion of the electrode 21.

[0046] Similar to the aforementioned catheter 10, in order to appropriately detect current from extravascular tissue and appropriately transmit current to extravascular tissue, the wire member 20 preferably has an electrical resistance value between the electrode 21 and the proximal end (rear end) of the wire member 20 of 100Ω or less, and more preferably 75Ω or less.

[0047] Figure 4 is a diagram showing a state in which valves 30 and 50 are connected to the intravascular device 1 of the first embodiment. Figure 5 is a diagram explaining the valve 30. Figure 5 shows a state where the valve 30 is connected to one end Sa of the sheath S. Figure 6 is a diagram explaining the valve 50. Figure 6 shows a state where the valve 50 is connected to the proximal end of the catheter 10. Figure 7 is a diagram explaining the structure of the valves 30 and 50. It is preferable that the intravascular device 1 includes the valves 30 and 50 that serve as a hemostatic structure for suppressing bleeding caused by insertion into a blood vessel.

[0048] The valve 30 is a first hemostatic structure connected to one end Sa positioned outside the blood vessel of the sheath S that inserts the intravascular device 1 into a living body's blood vessel. In the present embodiment, the proximal end side of the catheter 10 with the wire member 20 inserted inside is passed through the valve 30, and by closing the valve 30, the space between the catheter 10 and the sheath S is made liquid-tight, and the catheter 10 is held. The valve 50 is a second hemostatic structure connected to the proximal end of the catheter 10 that extends outward (proximally) through the valve 30. In addition, in the present embodiment, the proximal end side of the wire member 20 is passed through the valve 50, and by closing the valve 50, the wire member 20 is held in a liquid-tight manner.

[0049] Hereinafter, each part of the valves 30 and 50 will be described with reference to FIGS. 4 to 7. The valves 30 and 50 have the same configuration except for the connected members and the like. Therefore, in FIG. 7, the reference numerals for each part of the valve 30 and the corresponding reference numerals for each part of the valve 50 are shown. The sheath S is a flexible cylindrical member, which is arranged from the body surface of a living body into the blood vessel, and is a member that can be partially placed in the blood vessel. The intravascular device 1 (the catheter 10 and the wire member 20) can be inserted into the sheath S, and the intravascular device 1 is inserted into the blood vessel through the sheath S. In addition, the sheath S is detachably connected to the joint part 31 of the valve 30.

[0050] Valve 30 has a T-shaped joint portion 31 and a compression portion 32 when viewed from the side. One end of the joint portion 31 is connected to one end Sa of the sheath S which is placed outside the blood vessel. The other end of the joint portion 31 has an enlarged diameter portion 311. The joint portion 31 also has a branched pipe 332 in its central part. Valve 50 has a similar shape to valve 30 and has a joint portion 51 and a compression portion 52. One end of the joint portion 51 is connected to the proximal end of the catheter 10 which is passed through valve 30. The other end of the joint portion 51 has an enlarged diameter portion 511. The joint portion 51 also has a branched pipe 532 in its central part.

[0051] These branched tubes 332 and 532, also known as side ports, are tubes used for removing air, drawing blood, and administering drugs that inhibit blood coagulation (e.g., heparinized saline). In particular, the branched tube 532 of valve 50 is suitably used for introducing drugs that inhibit blood coagulation (e.g., heparinized saline) into the catheter 10. The drugs introduced through the branched tube 532 flow through the catheter 10, preventing the formation of thrombi due to blood stagnation. The intravascular device 1 is left in the blood vessel for more than one hour, and in some cases more than one day, to perform measurements. Therefore, there is a risk of blood flow stagnation and thrombus formation within the catheter 10, but since the drugs described above can be introduced through the branched tube 532, such thrombosis can be prevented. Furthermore, if a drug that inhibits blood coagulation (for example, heparinized saline solution) is introduced from the branch pipe 332 on the valve 30 side, it is possible to suppress the accumulation of blood in the space between the sheath S and the catheter 10 and the formation of thrombi.

[0052] As shown in Figure 7, the enlarged portion 311 of valve 30 has a cylindrical end 312 and a reduced-diameter portion 313 located on the sheath S side of the end 312. The enlarged portion 511 of valve 50 has a cylindrical end 512 and a reduced-diameter portion 513 located on the catheter 10 side of the end 512. Inside the enlarged portions 311, 511, cylindrical members 33, 53 are provided in the space surrounded by the ends 312, 512 and the reduced-diameter portions 313, 513. The cylindrical members 33, 53 are made of an elastically deformable material. Here, "elastically deformable" means not only fully elastically deformable but also partially elastically deformable. Male threads 314, 514 are threaded on the outer circumference of the ends 312, 512.

[0053] The compression sections 32 and 52 each have a cylindrical outer section 321 and 521, a reduced diameter end section 322 and 522 located on the opposite side from the joint section 31 and 51, and pressing protrusions 324 and 524 that project from the center of the reduced diameter end section 322 and 522 toward the reduced diameter section 313 and 513 of the enlarged diameter section 311 and 511 (downward in Figure 7). Female threads 325 and 525 are threaded on the inner circumferential surface of the outer section 321 and 521, and these female threads 325 and 525 are screwed into the male threads 314 and 514. As a result, the compression sections 32 and 52 are rotatably supported relative to the enlarged diameter section 311 and 511.

[0054] By rotating the compression sections 32 and 52 to bring the pressing protrusions 324 and 524 closer to the diameter-reducing sections 313 and 513, the pressing protrusions 324 and 524 come into contact with the axial end faces (upper end faces shown in Figure 7) of the cylindrical members 33 and 53, and the pressing protrusions 324 and 524 and the diameter-reducing sections 313 and 513 compress the cylindrical members 33 and 53 in the axial direction. Since the outer circumferential surfaces of the cylindrical members 33 and 53 come into contact with the inner circumferential surfaces of the ends 312 and 512, the cylindrical members 33 and 53 are compressed so as to move closer to the axis of the cylindrical members 33 and 53, that is, so that the spaces 33a and 53a formed by the inner circumferential surfaces of the cylindrical members 33 and 53 are reduced.

[0055] In valve 30, with the catheter 10 passed through the space 33a, the cylindrical member 33 is compressed, causing the space 33a to collapse and the catheter 10 to be held by the cylindrical member 33. Similarly, in valve 50, with the wire member 20 passed through the space 53a, the cylindrical member 53 is compressed, causing the space 53a to collapse and the wire member 20 to be held by the cylindrical member 53. When the valves 30 and 50 described above are attached to the intravascular device 1, as shown in Figure 4, multiple wires 13 extend to the outside of the catheter 10 from a hole (not shown) at the proximal end of the catheter 10 located between valves 30 and 50.

[0056] (Placement Method of Intravascular Device 1, etc.) The placement method of the intravascular device 1, etc., for correctly sensing the area to be removed when surgically removing a portion of brain tissue in cases of intractable epilepsy (epilepsy in which seizure symptoms are not relieved by medication), etc., will be explained. Figure 8 is a diagram showing an example of an intravascular device 1 placed in a cerebral blood vessel. Figure 8 shows a case in which an intravascular device 1 is made by inserting a wire member 20 into a catheter 10. First, the operator inserts the tip of the sheath S into the blood vessel from the body surface, such as the neck of the living body. Next, the operator inserts a guide wire member (not shown) into the catheter 10 in advance and combines them, and inserts them into the blood vessel from the sheath S. The operator moves the catheter 10 and guide wire together inside the blood vessel and places them in a cerebral blood vessel B1 close to the measurement area.

[0057] Next, the operator removes the guidewire and inserts the wire member 20 into the catheter 10. The operator then pushes the wire member 20 inward to move it within the catheter 10, causing it to protrude and position the electrode 21 of the wire member 20 within the blood vessel B2 of the brain near the measurement area. Next, without moving the position of the electrode 21 of the wire member 20, the operator retracts only the catheter 10 and positions it at an arbitrary position within the blood vessel B1 near the measurement area. As shown in Figure 8, the catheter 10 is placed on the side of the blood vessel B1 that is wider than the blood vessel B2 where the electrode 21 of the wire member 20 is positioned. At this time, it is preferable that the distance between the electrode 21 of the wire member 20 and the electrode 11 of the catheter 10 be 5 mm or more from the viewpoint of achieving highly sensitive detection.

[0058] Next, the operator connects one end of the joint portion 31 of the valve 30 to one end Sa of the sheath S located outside the blood vessel, and inserts the proximal end of the catheter 10 into the space 33a of the cylindrical member 33. Next, the operator rotates the compression portion 32 to close the valve 30 and compresses the cylindrical member 33 by pressing it against the reduced diameter portion 313 with the pressing projection 324. Then, due to the elastic deformation of the cylindrical member 33, the space 33a collapses, and the cylindrical member 33 comes into close contact with the outer surface of the catheter 10. As a result, the space between the sheath S and the catheter 10 becomes liquid-tight in this area, and the catheter 10 is held in place.

[0059] Next, the operator connects one end of the joint portion 51 of the valve 50 to the proximal end of the catheter 10 and inserts the proximal end portion of the wire member 20 into the space 53a of the cylindrical member 53. Next, the operator rotates the compression portion 52 to close the valve 50 and compresses the cylindrical member 53 by pressing it against the reduced diameter portion 513 with the pressing projection 524. Then, due to the elastic deformation of the cylindrical member 53, the space 53a collapses and the cylindrical member 53 comes into close contact with the wire member 20. As a result, the wire member 20 is held in a liquid-tight manner in this portion. As described above, the valves 30 and 50 suppress bleeding associated with the insertion of the intravascular device 1 into the blood vessel.

[0060] Next, the sheath S, wire member 20, and conductor 13 are fixed to the living body by fixing members (not shown). The base end of the wire member 20 is connected to a calculation unit (not shown) that calculates the electroencephalogram measurement results, so as to be able to output potential information obtained from the electrode 21. The base end of the conductor 13 is also connected to the calculation unit so as to be able to output potential information obtained from the electrode 11. The calculation unit then acquires and calculates the potential information from the electrode 11 and electrode 21, so as to be able to sense with high accuracy the area to be removed when surgically removing a portion of brain tissue in cases of intractable epilepsy, etc.

[0061] Here, "the base end of the wire member 20 is connected to the calculation unit so that potential information obtained from the electrode 21 can be output" is not limited to the case where the base end of the wire member 20 is electrically connected to the calculation unit by being physically connected by an insulated conductor, etc., but also includes cases where, for example, the base end of the wire member 20 is electrically connected to a voltage measuring instrument by being physically connected by an insulated conductor, and the voltage measuring instrument and the remote server are electrically connected by radio waves so that the voltage measuring instrument can transmit a signal to the remote server, or cases where means other than electrical means are used instead of radio waves. The same applies to "the base end of the conductor 13 is also connected to the calculation unit so that potential information obtained from the electrode 11 can be output".

[0062] As described above, the intravascular device 1, with its arrangement, minimizes contact between the wire member 20 and the catheter 10 and the blood vessel, making it less likely to cause adverse events even when left in place for extended periods. Therefore, the intravascular device 1 can be left in a blood vessel for more than one hour (specifically, more than two hours, more than one day, more than two days, more than five days, more than seven days, more than two weeks, or more than one month) while minimizing the burden on the body, and can accurately detect the area to be removed when surgically removing a portion of brain tissue in cases such as intractable epilepsy.

[0063] Figure 9 shows an example of an intravascular device 1 placed in a cerebral blood vessel. As mentioned above, the intravascular device 1 may be in the form of two or more wire members 20 combined with a catheter 10. Figure 9 shows a case in which two wire members 20A and 20B are inserted into the catheter 10 as the intravascular device 1. In this case, as mentioned above, the operator positions the first wire member 20A so that the electrode 21A is located in a blood vessel B2 near the measurement area, then retracts the catheter 10 by a predetermined distance, inserts the second wire member 20B into the catheter 10, moves through the catheter 10 into the cerebral blood vessel, and positions it so that the electrode 21B is located in a blood vessel B3 near the measurement area.

[0064] After positioning the second wire member 20B, the catheter 10 is again moved back a predetermined distance towards the proximal end and positioned at an arbitrary location within the blood vessel B1 near the measurement area. As shown in Figure 9, the electrodes 21A and 21B of the wire members 20A and 20B are positioned at two locations near the measurement area, and the multiple electrodes 11 of the catheter 10 are positioned at a predetermined distance from the electrodes 21A and 21B, enabling detection of nerve tissue activity with higher sensitivity.

[0065] Figure 10 shows an example in which multiple wire members 20 are passed through a valve 50. In Figure 10, as an example, an example is shown in which three wire members 20 are passed through a valve 50. When multiple wire members 20, particularly three or more wire members 20, are inserted into a single catheter 10 as an intravascular device 1, the wire members 20 may come into contact with each other in the space 53a of the cylindrical member 53 of the valve 50, creating a gap between the wire members 20. Therefore, the wire members 20 cannot be held liquid-tight by airtight contact by the cylindrical member 53 alone. In such cases, it is preferable to insert at least one of the multiple wire members 20 into the space 53a of the cylindrical member 53 with a silicone tube T attached to its base end, and then rotate the compression part 52 to close the valve 50.

[0066] The silicone tube T is an elastically deformable member that can be fitted along the outer surface of the wire member 20 by allowing the wire member 20 to be inserted into its lumen. By closing the valve 50 with the silicone tube T fitted to the wire member 20, the elastically deformed silicone tube T reliably fills the space created by the wire members 20 contacting each other, ensuring a liquid-tight seal. From the viewpoint of making it easier to pass the wire member 20 through the silicone tube T, it is preferable that the inner diameter of the silicone tube T be 1.05 times or more the outer diameter of the wire member 20. Furthermore, from the viewpoint of ensuring sufficient contact between the inner surface of the silicone tube T and the outer surface of the wire member 20, and preventing gaps from forming when the valve 50 is closed, it is preferable that the inner diameter of the silicone tube T be 5 times or less the outer diameter of the wire member 20. In this embodiment, as an example, the outer diameter of the wire member 20 is 0.28 mm, and the silicone tube T fitted to it has an inner diameter of 1 mm and an outer diameter of 2 mm.

[0067] By using such a silicone tube T, when the compression section 52 is rotated to close the valve 50, the space 53a is crushed due to the elastic deformation of the cylindrical member 53 and the silicone tube T, and the cylindrical member 53 and the crushed silicone tube T come into close contact with the outer surface of the wire member 20. As a result, the wire member 20 is held in a liquid-tight manner by the valve 50.

[0068] Two of these intravascular devices 1 are used during measurement. They are inserted into blood vessels in the left and right neck regions of the body, respectively, and positioned within the blood vessels of the brain. The other intravascular device 1 is positioned within a cerebral blood vessel at a predetermined distance from the first intravascular device 1. For example, if the first intravascular device 1 is positioned on the left side of the brain, the second intravascular device 1 is positioned on the right side of the brain. It is preferable that the distance between the two intravascular devices 1 be 1 cm or more, and 2 cm or more is preferable from the viewpoint of ensuring clear measurement. The cerebral blood vessels in which the intravascular devices 1 are positioned may be venous sinuses (e.g., superior sagittal sinus, sigmoid sinus, transverse sinus, straight sinus, inferior sagittal sinus), cerebral veins such as the internal jugular vein, cortical veins, and internal cerebral vein, or cerebral arteries such as the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery.

[0069] In this embodiment, the intravascular device 1 was described as being used to detect the activity of nerve tissue outside the blood vessels of the brain. However, it is not limited to this, and it is also possible to supply electricity to electrodes 11 and 21 from a power source (not shown) to stimulate the activity of nerve tissue with high efficiency. As a result, for diseases where the causative site is located deep in the brain (epilepsy, depression, involuntary movements due to Parkinson's disease, prolonged disorders of consciousness, etc.), the intravascular device 1 can be used to appropriately position electrodes 11 and 21 at the causative site and supply electrical stimulation to treat these diseases.

[0070] This embodiment provides the following advantages. The catheter 10 of this embodiment is a catheter placed in the blood vessels of the brain of a living organism and equipped with electrodes for detecting or stimulating the activity of nerve tissue located outside the blood vessels. It comprises at least one electrode 11 provided at the tip portion inserted into the blood vessel B1, and a conductor 13 provided for each electrode 11, with one end electrically connected to the electrode 11. The intravascular device 1 of this embodiment comprises this catheter 10 and a wire member that can be inserted into the lumen of the catheter 10 and is equipped with at least one electrode 21 at its tip. Therefore, this embodiment is minimally invasive, significantly reduces the burden on the living body, and can freely enter even narrow blood vessels that cannot be entered by intravascular devices in the form of stents with electrodes, enabling detection or stimulation of nerve tissue activity with high sensitivity. This allows for highly accurate identification of the resection site.

[0071] Furthermore, according to this embodiment, the valves 30 and 50 can hold the wire member 20 and the like in a liquid-tight manner, thereby reducing the amount of bleeding associated with the insertion of the intravascular device 1 into a blood vessel and reducing the burden on the body.

[0072] Furthermore, in conventional intravascular devices where electrodes are attached to a stent, the length of the stent cannot be increased, limiting the area where electrodes can be placed. In contrast, with the intravascular device 1 of this embodiment, electrodes can be placed on any part of the catheter 10, so the area to be detected or stimulated can be freely set. Also, with the intravascular device 1 of this embodiment, a wire member 20 equipped with an electrode 21 is combined with a catheter 10 equipped with an electrode 11, and the electrode 11 and electrode 21 can be placed in different blood vessels, so the activity of nerve tissue at any location can be detected or stimulated. Moreover, with the intravascular device 1 of this embodiment, the wire member 20 and catheter 10 can enter even narrow blood vessels, and the area to be detected or stimulated can be freely selected, so it can be used, for example, as an intracardiac electrocardiogram or electromyogram.

[0073] (Second Embodiment) Figure 11 is a diagram illustrating the intravascular device 2 of the second embodiment. Figure 11 shows the intravascular device 2 in a state where it is implanted in a blood vessel B1 of the brain. The intravascular device 2 of the second embodiment differs from the intravascular device 1 of the first embodiment in that it does not have a wire member 20 and consists only of a catheter 10, but otherwise it has the same form as the intravascular device 1 of the first embodiment. Therefore, the same reference numerals are used for parts that perform the same functions as those of the first embodiment described above, and redundant explanations are omitted as appropriate.

[0074] The intravascular device 2 of this embodiment, like the intravascular device 1 of the first embodiment, is equipped with valves 30 and 50. Since the intravascular device 2 does not have a wire member 20, the valve 50 is closed with the wire member 20 not passing through the cylindrical member 53 of the valve 50. This closes the proximal end of the catheter 10, preventing blood and other fluids inside the catheter 10 from flowing out to the outside.

[0075] The intravascular device 2 of the second embodiment is placed in a blood vessel B1 of the brain as follows: The operator combines a guide wire (not shown) with the catheter 10 and moves it through the sheath S to a blood vessel B1 near the measurement area in the brain. Then, the operator removes the guide wire and leaves only the catheter 10 in the blood vessel B1.

[0076] Even when the intravascular device 2 consists only of a catheter 10 as in this embodiment, the multiple electrodes 11 on the catheter 10 make it minimally invasive, significantly reducing the burden on the body, and allowing it to freely enter narrow blood vessels that cannot be accessed by intravascular devices with electrodes on a stent, enabling highly sensitive detection or stimulation of nerve activity. This allows for highly accurate identification of the resection site. Furthermore, since the intravascular device 2 of this embodiment is equipped with valves 30 and 50, the amount of bleeding associated with the insertion of the intravascular device 2 into a blood vessel can be reduced, thereby reducing the burden on the body.

[0077] Furthermore, in conventional intravascular devices where electrodes are attached to a stent, the length of the stent cannot be increased, and the area where electrodes can be placed is limited. However, with the intravascular device 2 of this embodiment, electrodes can be placed on any part of the catheter 10, so the area to be detected or stimulated can be freely set. In addition, with the intravascular device 2 of this embodiment, the catheter 10 can enter even narrow blood vessels, and the area to be detected or stimulated can be freely selected, so it can be used for measurements such as intracardiac electrocardiograms and electromyograms.

[0078] (Third Embodiment) Figure 12 is a diagram illustrating the intravascular device 3 of the third embodiment. Figure 12 shows the tip portion of the intravascular device 3. The intravascular device 3 of the third embodiment differs from the intravascular device 1 of the first embodiment in that it is equipped with a second catheter 40 at the proximal end of the catheter 10, the second catheter 40 having an inner diameter larger than the outer diameter of the catheter 10, but otherwise it has the same form as the intravascular device 1 of the first embodiment. Therefore, the same reference numerals are used for parts that perform the same functions as those of the first embodiment described above, and redundant explanations are omitted as appropriate. Note that in Figure 12, for ease of understanding, the intravascular device 3 is shown as having one wire member 20, but it is not limited to this and may have two or more. Furthermore, the intravascular device 3 of this embodiment may be in a form without a wire member 20, as in the second embodiment.

[0079] The second catheter 40 has a layered structure and other features substantially the same as the catheter 10 shown in the first embodiment, but its inner diameter is larger than the outer diameter of the catheter 10, allowing the catheter 10 to be inserted into its lumen. The second catheter 40 is also equipped with at least one electrode 41 at its tip. In this embodiment, as an example, an example in which five electrodes 41 are provided on the second catheter 40 is shown, but the number of electrodes 41 is not particularly limited. In this embodiment, an example in which one catheter 10 is inserted into the second catheter 40 is shown, but it is not limited to this, and a configuration in which two or more catheters 10 are inserted is also possible.

[0080] The method for implanting the intravascular device 3 of this embodiment into the cerebral blood vessels will now be described. First, the operator inserts a guide wire (not shown) into the lumen of the second catheter 40 and moves it through the sheath S to the cerebral blood vessels near the measurement area. Next, with the second catheter 40 positioned in the blood vessel, the operator removes the guide wire from the second catheter 40.

[0081] Next, the operator inserts a guidewire (not shown) into the lumen of catheter 10, and then inserts the combined catheter into the lumen of catheter 40, moving catheter 40 to its tip. Then, catheter 10 and the guidewire together are made to protrude distally from the opening at the tip of catheter 40, and delivered into a blood vessel even closer to the measurement area. Next, the operator removes the guidewire from catheter 10.

[0082] Next, the operator inserts the wire member 20 into the lumen of the catheter 10 and moves the wire member 20 through the catheter 10 to its tip. Then, the operator extends the wire member 20 out from the tip of the catheter 10 and positions the electrode 21 in a blood vessel located closer to the measurement area. Next, without moving the wire member 20, the operator moves only the catheter 10 proximal to the proximal end and positions it at an arbitrary position in the blood vessel. As a result, the catheter 10 is placed on the side of the blood vessel wider than the blood vessel where the electrode 21 of the wire member 20 is placed, similar to the first embodiment. Also, similar to the first embodiment, it is preferable that the distance between the electrode 21 of the wire member 20 and the electrode 11 of the catheter 10 be 5 mm or more from the viewpoint of achieving highly sensitive detection and stimulation. The operator may also move the second catheter 40 proximal to the proximal end while leaving the wire member 20 and catheter 10 in place, depending on the measurement area.

[0083] In this embodiment, a second catheter 40 is passed through and held in a valve 30 to which a sheath S is connected. A valve (not shown) is connected to the proximal end of the second catheter 40, and a catheter 10 is passed through and held in this valve (not shown). A valve 50 is connected to the proximal end of the catheter 10, and a wire member 20 is passed through and held in the valve 50. However, the arrangement of valves and other components may be changed as appropriate.

[0084] The operator electrically connects the base end of the wire member 20 and the base ends of the conductor 13 of the catheter 10 and the conductor of the second catheter 40 to the calculation unit of a measuring device (not shown). This allows the calculation unit to acquire potential information from electrodes 11, 21, and 41 and perform calculations, enabling it to sense the area to be excised with high accuracy.

[0085] According to this embodiment, the intravascular device 3 has more electrodes than the intravascular devices 1 and 2 of the first and second embodiments, and the electrodes 21 of the wire member 20, the electrodes 11 of the catheter 10, and the electrodes 41 of the second catheter 40 can be arranged in different regions. As a result, the intravascular device 3 of this embodiment can detect or stimulate nerve tissue activity with higher sensitivity, and the accuracy of identifying the resection site can be further improved.

[0086] (Modified Forms) The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the scope of the present invention. (1) The electrode 11 at the very tip of the catheter 10 may be located at the tip of the catheter 10. Also, the electrode 21 of the wire member 20 may be provided at a position away from the tip of the wire member 20, that is, at a position closer to the proximal end from the tip.

[0087] (2) The valves 30 and 50 can be modified as appropriate, as long as they can hold the intravascular device 1 in a liquid-tight manner. For example, the silicone tube T can be made of a highly biocompatible, elastically deformable material (elastic material) and, when the valve 50 is closed, can fill the space between the multiple wire members 20 together with the cylindrical member 53. For example, a polyvinyl chloride tube, a nylon elastomer tube, etc., may be used, or a member having a shape other than a tube may be used.

[0088] (3) The wire member 20 may have a region that is not covered with an insulator around its entire circumference to form a ring-shaped electrode 21. Alternatively, the wire member 20 may be configured to have multiple electrodes 21.

[0089] (4) In addition to the tip portion, electrodes 11 provided on the catheter 10 may also be provided several centimeters or more than ten centimeters proximal to the tip portion. For example, three electrodes 11 may be provided on the tip portion of the catheter 10, and three more electrodes 11 may be provided several centimeters proximal to the tip portion.

[0090] (5) In the first embodiment, the intravascular device 1 may be configured to include a plurality of catheters 10, and a plurality of catheters 10 may be inserted into a single sheath S. In this case, since a plurality of catheters 10 are passed through the valve 30, it is preferable to attach an elastically deformable silicone tube for the catheter 10, such as the silicone tube attached to the wire member 20 shown in the first embodiment, to at least one catheter 10. This silicone tube for the catheter 10 has an inner diameter larger than the outer diameter of the catheter 10, can be attached by inserting the catheter 10, and can fill the space created by the contact between the plurality of catheters 10. In this case, there may be one wire member 20 inserted into the catheter 10, or there may be two or more.

[0091] (6) In each embodiment, if there is only one catheter 10 to be inserted into the sheath S, the valve 30 may be a general-purpose sheath cannula valve.

[0092] The embodiments and variations described above can be used in combination as appropriate, but a detailed explanation is omitted. Furthermore, the present invention is not limited to the embodiments described above.

[0093] 1, 2, 3 Intravascular device 10 Catheter 11 Electrode 121 First layer 122 Second layer 123 Third layer 13 Conductor 20 Wire component 21 Electrode 30 Valve 50 Valve 40 Second catheter 41 Electrode S Sheath

Claims

1. A catheter positioned within the blood vessels of the brain of a living organism and equipped with electrodes for detecting or stimulating the activity of nerve tissue located outside the blood vessels, comprising: at least one electrode provided at the tip portion inserted into the blood vessel; and a conductor provided for each electrode, with one end electrically connected to the electrode.

2. The catheter according to claim 1, wherein the catheter is formed by stacking a plurality of layers radially to form a single unit, the conductor is arranged in one of the layers between the plurality of layers so as to extend toward the proximal end of the catheter, and the conductor is insulated from two adjacent layers.

3. The catheter according to claim 1, wherein the electrical resistance between the electrode and the other end of the conductor is 100 Ω or less.

4. An intravascular device comprising: a catheter according to any one of claims 1 to 3; a wire member that is insertable into the lumen of the catheter and has at least one wire-side electrode at its tip, wherein the wire member is inserted into the lumen of the catheter and protrudes from the tip of the catheter within the blood vessel, and the wire-side electrode is located at a distal position to the electrode, and the device detects or stimulates the activity of nerve tissue where both the wire-side electrode and the electrode are located outside the blood vessel.

5. The intravascular device according to claim 4, comprising a first hemostatic structure having a valve connected to one end of a sheath located outside the blood vessel for inserting the intravascular device into a blood vessel of a living body, the valve having an elastically deformable cylindrical member, and the cylindrical member holding the catheter by being compressed while the catheter is passed through the cylindrical member.

6. The intravascular device according to claim 4, comprising a second hemostatic structure connected to the proximal end of the catheter and having a valve for holding the wire member in a liquid-tight manner, wherein the valve has an elastically deformable cylindrical member, and the cylindrical member holds the wire member by being compressed while the wire member is passed through the cylindrical member.

7. The intravascular device according to claim 4, wherein the electrode and the wire-side electrode are left in the blood vessel for one day or more.

8. The intravascular device according to claim 4, wherein the blood vessel in which the electrodes and wire-side electrodes of the intravascular device are arranged is a cerebral vein.

9. A flexible catheter comprising: at least one electrode provided at one end; and a conductor provided for each electrode, with one end electrically connected to the electrode, wherein the electrical resistance between the electrode and the other end of the conductor is 100 Ω or less.

10. The catheter according to claim 9, wherein the one end on which the electrode is provided is left in a blood vessel for one day or more.

11. The catheter according to claim 9, wherein the blood vessel to which the one end on which the electrode is provided is located is a cerebral vein.

12. An intravascular device comprising a catheter according to any one of claims 9 to 11, wherein one end is positioned within a blood vessel of a living organism and is used for detecting or stimulating the activity of nerve tissue located outside the blood vessel.

13. The intravascular device according to claim 12, comprising a first hemostatic structure having a valve connected to one end of a sheath located outside the blood vessel for inserting the intravascular device into a blood vessel, the valve having an elastically deformable cylindrical member, the cylindrical member holding the catheter by being compressed while the catheter is passed through the cylindrical member.

14. The intravascular device according to claim 12, further comprising a second hemostatic structure connected to the other end of the catheter, which is located outside the blood vessel and opposite to the one end in the longitudinal direction of the catheter, and which closes the other end.

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