conduit

Abstract

The conduit includes: a hollow shaft; a front electrode disposed at the front end of the hollow shaft; a base electrode disposed at the base end of the hollow shaft and electrically connected to the front electrode via the hollow shaft; and a connecting portion configured to be detachable from the base electrode and electrically connected to an external voltage output device via a lead wire by being mounted on the base electrode.

Description

Technical Field

[0001] This invention relates to a catheter. Background Technology

[0002] In recent years, minimally invasive catheter ablation has become a representative treatment for conditions such as arrhythmia. During catheter ablation, a medium-to-high frequency current flows from the tip of the catheter towards the lesion, ablating the affected area.

[0003] Patent Document 1 discloses an energizing system for a cardiac ablation catheter. In the catheter system described in Patent Document 1, an accessory with a Luer lock mechanism is provided on the hand side of the catheter, and leads and connection terminals are provided for electrical connection to an output device via the accessory.

[0004] Patent Document 2 discloses an electrode catheter used in the examination (diagnosis) and treatment of arrhythmia. This electrode catheter includes a wire connecting an electrode located at the front end of the catheter channel and a connector located at the proximal end of the catheter channel. A portion of the handle is split to allow for detachment. During the manufacture of the electrode catheter, the split portion is removed, and the base of the wire and the connector are soldered together to establish an electrical connection.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Publication No. 8-508917

[0008] Patent Document 2: Japanese Patent Application Publication No. 2014-180498 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] In catheter-based treatments, such as PCI (percutaneous coronary intervention), delicate manipulation by the surgeon is required to avoid vascular perforation and intimal damage. However, the catheter described in Patent Document 1 is difficult to manipulate due to its accessories and lead wire. In particular, when rotating the catheter, the lead wire may become entangled in the axis of rotation, potentially hindering the operation. In the electrode catheter described in Patent Document 2, no research was conducted regarding the reduced operability caused by connecting the electrode catheter to an external device via the lead wire. Furthermore, such issues are common to all catheters inserted into the lumens of organisms such as the vascular system, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs.

[0011] The present invention was made to solve at least part of the above-mentioned problems, and its object is to provide a technique for improving the operability of a catheter in a catheter having electrodes.

[0012] Solution for solving the problem

[0013] This invention was made to solve at least a part of the above-mentioned problems and can be implemented as follows.

[0014] (1) According to one aspect of the present invention, a conduit is provided. The conduit comprises: a hollow shaft; a front end electrode disposed at the front end of the hollow shaft; a base end electrode disposed at the base end of the hollow shaft and electrically connected to the front end electrode via the hollow shaft; and a connecting portion configured to be detachable from the base end electrode and electrically connected to an external voltage output device via a lead wire by being mounted to the base end electrode.

[0015] According to this structure, since it has a connector that can be attached and detached from the base electrode, the connector can be detached from the base electrode when the surgeon inserts the catheter into the body and advances it within the blood vessel. By detaching the connector, the same operability as a catheter without leads or electrodes can be obtained. On the other hand, when the catheter's tip electrode reaches the target position and is cauterized, and when conduction is required, the connector can be attached to the base electrode and connected to an external voltage output device, thereby establishing energization. In other words, by having a detachable connector, a catheter that provides good operability when conductivity is not required and can conduct electricity when needed can be provided.

[0016] (2) In the conduit of the above manner, the connecting portion preferably includes a covering portion that covers the base electrode when assembled with the base electrode. In this way, since the base electrode is covered by the connecting portion, the possibility of leakage due to exposure of the base electrode can be reduced.

[0017] (3) In the catheter described above, it is preferable to further include a holding portion located at the base end of the hollow shaft. This holding portion has a front holding portion disposed at the front end of the holding portion, a base holding portion disposed at the base end of the holding portion, and an intermediate holding portion disposed between the front holding portion and the base holding portion. The connecting portion constitutes the intermediate holding portion. In this way, since the connecting portion also functions as an intermediate holding portion, the catheter can be easily operated even when the connecting portion is installed.

[0018] (4) In the conduit of the above-described manner, it is preferable to further include a replacement portion that can be attached and detached from the base electrode. When the base electrode is not fitted with the connecting portion but is fitted with the base electrode in place of the connecting portion, the intermediate holding portion is formed whereby the base electrode is not electrically connected to the voltage output device. In this way, since the base electrode is covered by the replacement portion even when the connecting portion is not fitted, the possibility of leakage current can be reduced.

[0019] (5) In the catheter described above, the covering portion is preferably configured to be openable and closable, and includes: a first cover portion having a first connecting terminal connected to the lead wire; and a second cover portion connected to the first cover portion via a hinged connection portion. The second cover portion is fitted to the base electrode in a closed state by being held between the first and second cover portions, and can be detached from the base electrode in an open state. When the connecting portion is fitted to the base electrode, the first connecting terminal is positioned in contact with the base electrode. This allows for easy installation and removal of the connecting portion through opening and closing operations. Therefore, the catheter can be quickly made conductive. Furthermore, since the first connecting terminal is positioned in contact with the base electrode when the connecting portion is fitted to it, conductivity can be easily ensured by simply fitting the connecting portion in a closed state with both the first and second cover portions.

[0020] (6) In the conduit of the above manner, at least one of the first cover and the second cover has an electrode groove for fitting the base electrode. When the connecting portion is assembled to the base electrode, the electrode groove is positioned at the contact point between the first connecting terminal and the base electrode. In this way, since the base electrode and the first connecting terminal are easily positioned appropriately, high-precision electrical connection to an external voltage output device is possible.

[0021] (7) In the conduit of the above manner, preferably at least one of the first cover and the second cover has a sealing portion that surrounds the outer periphery of the groove for the electrode. In this way, leakage current can be suppressed because water immersion of the base electrode can be suppressed.

[0022] (8) In the catheter described above, it is preferable that the base holding portion includes a support portion located at the front end of the base holding portion to fix and support the base electrode. The support portion has a protrusion extending from the central axis of the hollow shaft toward the outer periphery of the holding portion, and the intermediate holding portion has a recess that engages with the support portion of the base holding portion. In this way, when the surgeon holds the intermediate holding portion and rotates the catheter, the rotational force applied to the intermediate holding portion is transmitted to the base electrode via the support portion, thus suppressing the free rotation of the intermediate holding portion and improving the torque transmission performance of the catheter.

[0023] (9) In the above-described conduit, it is preferable that the front end holding portion has a tapered portion that narrows towards its own front end, and the tapered portion has a spiral groove formed on its surface. In this way, the tapered portion is softened, which can suppress the twisting of the hollow shaft.

[0024] (10) In the above-described conduit, preferably when the intermediate holding portion is formed by the connecting portion, the front holding portion allows the lead wire to be supported along the surface of the front holding portion, and has a lead wire recess on its own surface for the lead wire to be fitted. In this way, since the lead wire can be positioned along the surface of the front holding portion, the reduction in operability caused by the lead wire can be suppressed.

[0025] (11) In the conduit of the above manner, it is preferable that the lead wire has a second connecting terminal disposed at its own front end and capable of being electrically connected to the voltage output device, and that the conduit has a terminal support portion at the front end holding portion capable of supporting the second connecting terminal. In this way, when the connecting portion is assembled, the electrical connection between the second connecting terminal and the voltage output device can be cut off, and when operating the conduit, the second connecting terminal can be fixed to the front end holding portion by the terminal support portion. Therefore, the second connecting terminal of the lead wire can move freely, thereby suppressing the reduction in operability caused by the lead wire being wrapped around the conduit, etc.

[0026] Furthermore, the present invention can be implemented in various ways, such as by means of catheters, catheter systems including catheters, sensors, delivery guidewires, plasma guidewires, and other devices. Attached Figure Description

[0027] Figure 1 This is a simplified diagram of the overall structure of the plasma guidewire system according to the first embodiment.

[0028] Figure 2 This is an explanatory diagram showing a simplified structure of the plasma conduit according to the first embodiment.

[0029] Figure 3 This is an explanatory diagram of the structure of the holding part in a plasma conduit.

[0030] Figure 4 This is an illustrative diagram schematically showing the structure of the hollow shaft and the base electrode.

[0031] Figure 5 This is an explanatory diagram schematically showing the structure of the support portion that provides fixed support for the base electrode.

[0032] Figure 6 This is a simplified diagram illustrating the structure of the connecting part.

[0033] Figure 7 This is an explanatory diagram that briefly shows the inner surface structure of the first cover and the second cover.

[0034] Figure 8 This is a simplified illustration of the front end face of the connector.

[0035] Figure 9 This is a simplified illustration of the base end face of the connector.

[0036] Figure 10 This is an explanatory diagram showing the situation where the first connection terminal is in contact with the base electrode.

[0037] Figure 11 This is an explanatory diagram that briefly shows the appearance of the front end holding portion of the plasma conduit according to the second embodiment.

[0038] Figure 12 This is an explanatory diagram that briefly shows the appearance of the terminal support portion of the plasma conduit according to the third embodiment.

[0039] Figure 13 This is an explanatory diagram showing a simplified structure of the plasma conduit according to the fourth embodiment.

[0040] Figure 14 This is an explanatory diagram schematically showing the structure of the support portion that provides fixed support for the base electrode.

[0041] Figure 15 This is a simplified illustration of the base end face of the connector.

[0042] Figure 16 This is an explanatory diagram that briefly shows the external structure of the plasma conduit according to the fifth embodiment. Detailed Implementation

[0043] <First Implementation>

[0044] Figure 1 This is a simplified diagram of the overall structure of the plasma guidewire system. The plasma guidewire system is primarily used to treat CTO (Chronic Total Occlusion) using the antegrade approach. Besides CTO treatment, the plasma guidewire system can also be used to treat mild to moderate stenosis, significant stenosis, and arrhythmia. The plasma guidewire system 1 consists of a plasma catheter 100, a plasma guidewire 400, and an RF generator 500. Figure 1 A simplified side view of the plasma conduit 100 is shown. Figure 1 For ease of explanation, this includes sections that describe the relative proportions of the sizes of each component in a manner different from reality. It also includes sections that exaggerate a portion of each component. Figure 1In this design, the left side is referred to as the "front end side" of each component, and the right side is referred to as the "base end side" of each component. Furthermore, regarding each component, the end located on the front end side is called the "front end," and the end located on the base end side is called the "base end." Additionally, the portion located at and near the front end is called the "anterior end portion," and the portion located at and near the base end is called the "base end portion." The front end side is inserted into the organism, while the base end side is operated on by surgeons or other personnel. The above aspects are... Figure 1 This also applies to the attached diagrams.

[0045] The plasma conduit 100 includes a hollow shaft 10, a front electrode 20 located at the front end of the hollow shaft 10, a base electrode (described below) located at the base end of the hollow shaft 10, a holding portion 50 located at the base end of the hollow shaft 10, and a connector 70. The plasma guide wire 400 has a front end piece 403 at its front end. The front end piece 403 is formed of a conductive metallic material, such as chromium-molybdenum steel, nickel-chromium-molybdenum steel, stainless steel such as SUS304, or nickel-titanium alloy.

[0046] RF generator 500 outputs high-frequency power between terminals 501 and 502. Terminal 501 is connected to plasma guide wire 400 via cable 503 and cable connector 504. Terminal 502 is connected to plasma conduit 100 via cable 505 and cable connector 506.

[0047] As shown in the attached figure, in the plasma guidewire system 1, the plasma guidewire 400 is inserted into the plasma conduit 100 and configured to protrude from the front end of the plasma conduit 100 for use.

[0048] The plasma conduit 100 is transported to the CTO. With the tip of the plasma guidewire 400 protruding from the front end of the plasma conduit 100, if high-frequency power is output from the RF generator 500 to the terminals 501 and 502, a current-current corona discharge is generated on the front end plate 403 due to the voltage difference between the front electrode 20 of the plasma conduit 100 and the front end plate 403 of the plasma guidewire 400. This current-current corona discharge can be used to ablate the CTO.

[0049] Figure 2 This is an explanatory diagram showing a simplified structure of the plasma conduit 100 according to the first embodiment. As described above, the plasma conduit 100 has a holding portion 50 at the base end of the hollow shaft 10. Figure 2 As shown in (A), the gripping portion 50 has a front end gripping portion 52 disposed at the front end of the gripping portion 50, a base end gripping portion 54 disposed at the base end of the gripping portion 50, and an intermediate gripping portion 56 disposed between the front end gripping portion 52 and the base end gripping portion 54. The gripping portion 50 is formed of an insulating resin.

[0050] The intermediate holding part 56 may be composed of a connecting part 40 that can be electrically connected to the RF generator 500 via a lead 42. For example... Figure 2 As shown in (B), a front electrode 20 is provided at the base end of the hollow shaft 10 via the hollow shaft 10. Figure 1 The base electrode 30 is electrically connected. The connection portion 40 is detachably formed on the base electrode 30. Figure 2 (A) shows the state in which the connecting part 40 is assembled with the base electrode 30. Figure 2 (B) shows the state after the connection part 40 has been removed from the base electrode 30.

[0051] The connecting portion 40 includes a covering portion 44 that covers the base electrode 30 when assembled with the base electrode 30, and a lead wire 42. Figure 2 (A)). The lead 42 has a second connection terminal 422 at its front end that can be electrically connected to the RF generator 500. In this embodiment, the second connection terminal 422 is connected to the cable connector 506 and via the cable connector 506 ( Figure 1 The cover portion 44 has a first connection terminal (described in detail below) that connects to the base electrode 30. The connection portion 40 is fitted to the base electrode 30. If the second connection terminal 422 is connected to the RF generator 500 via the cable connector 506, the cable 505, and the terminal 502, then the base electrode 30 is electrically connected to the RF generator 500.

[0052] The front end gripping portion 52 has a tapered portion 522 that tapers towards its front end. The tapered portion 522 has a spiral groove 524 formed on its surface. Because the front end gripping portion 52 has a tapered portion 522 with the spiral groove 524, the abrupt change in rigidity between the front end gripping portion 52 and the intermediate shaft 10 is mitigated, achieving a gradual change in rigidity between the front end gripping portion 52 and the intermediate shaft 10. This suppresses the twisting of the hollow shaft 10. Furthermore, when the intermediate gripping portion 56 is formed by the connecting portion 40, the front end gripping portion 52 can support the lead wire 42 such that it runs along the surface of the front end gripping portion 52, and has a lead wire recess 526 on its surface for lead wire engagement. Because the front end gripping portion 52 has the lead wire recess 526, the lead wire 42 can run along the surface of the front end gripping portion, suppressing any reduction in operability caused by the lead wire 42.

[0053] Figure 3This is an explanatory diagram illustrating the structure of the holding portion 50 in the plasma conduit 100. As described above, in the plasma conduit 100 of this embodiment, the intermediate holding portion 56 can be constituted by the connecting portion 40. Furthermore, the intermediate holding portion 56 can also be constituted by the replacement portion 60. That is, the plasma conduit 100 is configured to allow for replacement of the connecting portion 40 and the replacement portion 60. Figure 3 (A)). The replacement part 60, like the connecting part 40, can be attached to and detached from the base electrode 30. When the connecting part 40 is not attached to the base electrode 30, it is attached to the base electrode 30 in place of the connecting part 40, forming the intermediate holding part 56. Figure 3 (B) The replacement part 60 does not have a lead 42, nor does it have a connection terminal for connecting to the base electrode 30. Therefore, when the replacement part 60 is assembled with the base electrode 30, the base electrode 30 is not electrically connected to the RF generator 500. When the replacement part 60 is assembled with the base electrode 30 and forms the intermediate holding part 56, the reduction in operability caused by the lead being wound around the holding part 50 and the hollow shaft 10 can be suppressed. In addition, since the replacement part 60 does not have a lead 42 and does not have a connection terminal for connecting to the base electrode 30, it is lighter than the connecting part 40 and easier to operate than when the connecting part 40 is assembled. Therefore, when the replacement part 60 is assembled, the plasma conduit 100 can be found to have the same operability as a general conduit without an energized structure.

[0054] Figure 4 This is an explanatory diagram schematically showing the structure of the hollow shaft 10 and the base electrode 30. Figure 4 (A) schematically shows the appearance of the hollow shaft 10 and the base electrode 30. Figure 4 In (A), the front end gripping part 52, the hollow shaft 10, and the base electrode 30 are shown exposed along the axis. As shown in the figure, the base electrode 30 is provided at the base end of the hollow shaft 10.

[0055] Figure 4 (B) is an explanatory diagram schematically showing the cross-sectional structure of the hollow shaft 10, illustrating... Figure 4 The AA section in (A). The hollow shaft 10 has a hollow outer shaft 12 and a hollow inner shaft 14 disposed within the outer cavity of the outer shaft 12. The outer shaft 12 and the inner shaft 14 are elongated strips with approximately circular cross-sections.

[0056] Inside the outer shaft 12, a hollow wire coil 16 formed by winding wire is embedded. The wire constituting the wire coil 16 is made of a conductive metallic material, such as stainless steel including SUS304, nickel-titanium alloy, or alloys of gold, platinum, and tungsten, which are X-ray non-transmitting materials. The wire coil 16 is connected to the front electrode 20 and the base electrode 30 in a manner that allows it to conduct electricity. The outer surface of the outer shaft 12 may also be coated with a waterproof resin or a hydrophobic resin.

[0057] Inside the inner shaft 14, a braided layer 18, which serves as a reinforcing member formed from braided wire, is embedded. The wire constituting the braided layer 18 is the same as that of the coil 16, and is formed of a conductive metallic material, such as stainless steel (e.g., SUS304), nickel-titanium alloy, gold (as an X-ray non-transmissive material), platinum, or tungsten-containing alloys. The coil 16 and the braided layer 18 may also be formed of other known conductive metallic materials besides those described above.

[0058] The outer shaft 12 and the inner shaft 14 are formed of an insulating resin, such as polyethylene, polypropylene, ethylene-propylene copolymer and other polyolefins, polyethylene terephthalate and other polyesters, polyvinyl chloride, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate copolymer, polyurethane and other thermoplastic resins, polyamide elastomers, polyolefin elastomers, polyurethane elastomers, silicone rubber, latex and the like. The outer shaft 12 and the inner shaft 14 may also be formed of other known materials besides those described above.

[0059] Figure 4 (C) is an illustrative diagram schematically showing the cross-sectional structure of the base electrode 30, illustrating... Figure 4 The BB section in (A) is shown. The base electrode 30 is a hollow tube with a roughly circular cross-section. Because the base electrode 30 is a hollow tube, the plasma guide wire 400 can pass through it via the connector 70, or a drug solution can be injected. The base electrode 30 is formed of a conductive metal material, such as stainless steel (e.g., SUS304), nickel-titanium alloy, aluminum, copper, gold, platinum, tungsten, or an alloy containing at least one of these. The resin layer of a portion of the outer shaft 12 at the base end of the hollow shaft 10 is peeled off and inserted into the cavity of the base electrode 30 with the wire coil 16 exposed. The base electrode 30 and the wire coil 16 are connected by welding. The front electrode 20, located at the front end of the hollow shaft 10, is also formed of a conductive metal material, similar to the base electrode 30, and is connected to the wire coil 16. Therefore, the front electrode 20 and the base electrode 30 are electrically connected via the wire coil 16. A PTFE (polytetrafluoroethylene) layer can also be formed on the inner surface of the base electrode 30. Forming a PTFE layer improves biocompatibility and lubrication. Alternatively, a PE (polyethylene) layer or a PA (polyamide) layer can be formed instead of a PTFE layer. Using PE or PA layers also improves biocompatibility and lubrication. Furthermore, by forming the front electrode 20 from materials such as gold, platinum, or tungsten-containing alloys that are X-ray non-transmissive, the front electrode 20 can function as an X-ray non-transmissive marker within the body cavity.

[0060] Figure 5 This is an explanatory diagram schematically showing the structure of the support portion 542 that provides fixed support for the base electrode 30. Figure 5 (A) shows a side view. Figure 5 Figure (B) shows a view from the front end gripping portion 52 side. The base end gripping portion 54 has a support portion 542 on its front end side for fixing and supporting the base end electrode 30. The support portion 542 has a protrusion 544 that protrudes from the central axis of the hollow shaft 10 (which coincides with the central axis of the base end electrode 30) toward the outer periphery of the intermediate gripping portion 56. Furthermore, the front end gripping portion 52 has a front end side support portion 528 on its base end side for fixing and supporting the base end electrode 30. The front end side support portion 528 is cylindrical, with its central axis coinciding with the central axis of the base end electrode 30. In this embodiment, the front end side support portion 528 does not have a protrusion such as the protrusion 544, but in other embodiments, the front end side support portion 528 may also have a protrusion. Alternatively, the support portion 542 may not have the protrusion 544, but the front end side support portion 528 may have a protrusion.

[0061] Figure 6 This is a simplified explanatory diagram (perspective view) showing the structure of the connecting part 40. Figure 7 This is an explanatory diagram that briefly shows the inner surface structure of the first cover 441 and the second cover 442. Figure 8 This is a simplified explanatory diagram showing the front end face 44a of the connecting part 40. Figure 9 This is a simplified explanatory diagram showing the base end face 44b of the connecting part 40. When the connecting part 40 is assembled to the base electrode 30, the front end face 44a is disposed on the front end side, and the base end face 44b is disposed on the base end side. Figure 6 , Figure 8 , Figure 9 (A) shows the closed state of the connection part 40. Figure 6 , Figure 8 , Figure 9 (B) shows the open state of the connecting part 40. As described above, the connecting part 40 includes a lead wire 42 and a covering part 44. The covering part 44 includes a first cover part 441 and a second cover part 442, which are connected by a hinged connection part 444, allowing it to be in the closed state ( Figure 6 (A) and open state ( Figure 6 Convert between (B) and ( ). For example Figure 7 As shown, the connecting part 444 includes a rotating shaft 444a and a rotating support part 444b having a hole for the rotating shaft to pass through. Figure 7 (A)), and rotating support 444c ( Figure 7(B)). The rotating support portion 444b is integrally formed with the first cover portion 441, and the rotating support portion 444c is integrally formed with the second cover portion 442. By inserting the rotating shaft 444a through the holes in the rotating support portions 444b and 444c, the first cover portion 441 and the second cover portion 442 can be connected in an openable and closable manner. The connecting portion 40 is in a closed state in which the base electrode 30 is clamped by the first cover portion 441 and the second cover portion 442. Figure 6 (A) is assembled on the base electrode 30, and is set to the open state ( Figure 6 (B) can be detached from the base electrode 30.

[0062] like Figure 7 As shown in (A), the first cover 441 includes an outer shell 441j and an inner shell 441k. Similarly, as... Figure 7 As shown in (B), the second cover 442 includes an outer shell 442j and an inner shell 442k. The outer shell 441j and outer shell 442j can be made of materials with high rigidity, such as polyamide resin, polyethylene resin, ABS (acrylonitrile-butadiene-styrene) resin, etc. The inner shell 441k and inner shell 442k can be made of materials with high flexibility, such as silicone resin, elastomer, rubber, etc.

[0063] like Figure 7 As shown, the second cover portion 442 has a button portion 442h and a hook portion 442i connected to the button portion 442h, and the first cover portion 441 has a hole portion 441i for the hook portion 442i to be hooked. If... Figure 6 As shown in (A), when the first cover 441 and the second cover 442 are in the closed state, the hook 442i engages with the hole 441i, maintaining the closed state. Furthermore, if the button 442h is pressed while the first cover 441 and the second cover 442 are in the closed state, the hook 442i connected to the button 442h is pulled out of the hole 441i, releasing the engagement between the hook 442i and the hole 441i, thereby opening the first cover 441 and the second cover 442. Thus, by closing the first cover 441 and the second cover 442, the surgeon can assemble the connecting part 40 onto the base electrode 30, and by pressing the button 442h, can detach the connecting part 40 from the base electrode 30. In other words, the connecting part 40 according to this embodiment provides convenience for the surgeon in attaching and detaching it.

[0064] like Figure 8 As shown, the lead wire 42 is configured to penetrate the first front end face 441a of the first cover portion 441. The first connecting terminal 421 disposed at one end of the lead wire 42 is configured to protrude from the inner surface 441c of the first cover portion 441. Figure 7 (A)). When the connecting part 40 is assembled to the base electrode 30, the first connecting terminal 421 is positioned in contact with the base electrode 30.

[0065] The first cover 441 has an electrode groove 441d in the inner shell 441k portion of its inner surface 441c, which allows the base electrode 30 to be fitted. Similarly, the second cover 442 has an electrode groove 442d in the inner shell 442k portion of its inner surface 442c, which allows the base electrode 30 to be fitted. When the first cover 441 and the second cover 442 are in the closed state, a through hole with a generally circular cross-section is formed by the electrode groove 441d and the electrode groove 442d. Figure 8 (A) Figure 9 (A)). If the connecting part 40 is assembled to the base electrode 30, the outer peripheral surface of the base electrode 30 is covered by the electrode groove 441d and the electrode groove 442d. Figure 7 As shown in (A), since the first connection terminal 421 is disposed in the electrode groove 441d, if the base electrode 30 is disposed in the electrode groove 441d, the base electrode 30 and the first connection terminal 421 can be easily disposed in the appropriate position, and thus can be electrically connected to the RF generator 500 with high precision.

[0066] The first cover 441 has a front-side recess 441e that can be fitted into the front-side support portion 528 of the front-end gripping portion 52, and a base-end recess 441f that can be fitted into the support portion 542 of the base-end gripping portion 54, in the inner shell 441k portion of the inner surface 441c. Similarly, the second cover 442 has a front-side recess 442e that can be fitted into the front-end support portion 528 of the front-end gripping portion 52, and a base-end recess 442f that can be fitted into the support portion 542 of the base-end gripping portion 54, in the inner shell 442k portion of the inner surface 442c. When the first cover 441 and the second cover 442 are in the closed state, the shape of the inner cavity formed by the base-end recess 441f and the base-end recess 442f is substantially the same as that of the support portion 542 of the base-end gripping portion 54. Figure 9 (A) As described above, the support portion 542 of the base holding portion 54 has a protrusion 544 protruding in the direction from the central axis of the hollow shaft 10 toward the outer periphery of the holding portion 50, and the connecting portion 40 has a base-side recess 441f and a base-side recess 442f for fitting into the support portion 542. Therefore, if the connecting portion 40 is assembled to the base electrode 30 to form an intermediate holding portion 56, when the surgeon holds the intermediate holding portion 56 and operates the catheter to rotate it, the rotational force applied to the intermediate holding portion 56 is transmitted to the base electrode 30 via the support portion 542. Therefore, the free rotation of the intermediate holding portion 56 can be suppressed, and the torque transmission of the plasma catheter 100 can be improved. The base-side recess 441f and the base-side recess 442f in this embodiment are also simply referred to as "recesses".

[0067] like Figure 7As shown in (B), a protruding sealing portion 442g is formed in the inner shell 442k portion of the inner surface 442c of the second cover portion 442, which surrounds the outer periphery of the groove portion 442d for the electrode. Figure 7 As shown in (A), in the inner shell 441k portion of the inner surface 441c of the first cover portion 441, a protruding sealing portion 441g spanning the front end side recess 441e and a protruding sealing portion 441g spanning the base end side recess 441f are formed corresponding to the sealing portion 442g of the second cover portion 442. Figure 7 In the diagram, the protruding sealing portions 441g and 442g are indicated by oblique shading. When the first cover portion 441 and the second cover portion 442 are in the closed state and assembled with the base electrode 30, the base electrode 30 can be surrounded by the sealing portions 441g and 442g. Therefore, during the use of the plasma catheter 100, etc., immersion of the base electrode 30 in water can be suppressed, thus suppressing leakage current. According to the connection portion 40 of this embodiment, for example, it can have waterproofness to prevent wetting of the hands of surgical personnel such as doctors by saline solution, which is clinically anticipated. Therefore, when the connection portion 40 is attached or detached during surgery, by assembling the connection portion 40, the base electrode 30 is surrounded by the sealing portions 442g and 441g, so that even if the base electrode 30 is wetted, it can remain insulated from the outer shell 441j and 442j of the connection portion 40. Therefore, safety against leakage current during discharge can be provided.

[0068] The replacement part 60 lacks the lead wire 42 and the first connecting terminal 421, but has a structure substantially the same as the connecting part 40. The first cover and the second cover can be detached and installed relative to the base electrode 30 by opening and closing. A sealing portion surrounding the base electrode 30 is formed on the inner surface of the first cover and the second cover. Therefore, even when the replacement part 60 is assembled to the base electrode 30, if the base electrode 30 is covered and the connecting part 40 is assembled, it has the same waterproof performance. In addition, the replacement part 60 has the same torque transmission performance as the connecting part 40.

[0069] Figure 10 This is an explanatory diagram showing the first connection terminal 421 in contact with the base electrode 30. Figure 10 In order to clearly show the situation of the first connecting terminal 421, the components other than the first connecting terminal 421 of the connecting portion 40 are omitted from the illustration. The first connecting terminal 421 has two contact portions 421a that contact the base electrode 30. If the base electrode 30 is clamped by the first cover portion 441 and the second cover portion 442, the first connecting terminal 421 contacts the base electrode 30 at the two 421a. Figure 10(A)). At this time, the hook 442i and the hole 441i are not yet hooked. By pressing the first cover 441 and the second cover 442 from the outside to the inside, the hook 442i hooks with the hole 441i, maintaining (locking) the closed state of the covering 44. Thus, when the first cover 441 and the second cover 442 are pressed, the first connecting terminal 421 is flattened, and the two contact portions 421a slide on the surface of the base electrode 30 in a manner that brings them closer together. Therefore, even if foreign matter is attached to the base electrode 30, it can be peeled off through the first connecting terminal 421, and good power transmission can be obtained.

[0070] In the plasma guidewire system 1 of this embodiment, for example, CTO clearance can be performed as follows. Initially, in the plasma catheter 100, a replacement part 60 is assembled at the base electrode 30 to form an intermediate holding part 56. In this state, the surgeon uses the plasma catheter 100. First, from the opening 104a at the front end of the plasma catheter 100... Figure 1 Insert the base end of the delivery guide wire (not shown) so that it is within the inner shaft 14 ( Figure 4 The plasma catheter 100 is passed through the inner lumen of the coronary artery and protrudes outward from the base of the inner lumen. The surgeon then manipulates the plasma catheter 100 by holding the holding part 50, which includes the replacement part 60, and transports the plasma catheter 100 along the delivery guidewire to the CTO formed in the coronary artery. Afterward, the surgeon passes the plasma catheter 100 through the connector 70 (… Figure 1 Contrast agent is injected into the inner lumen of the inner shaft 14 for X-ray imaging, etc., and the plasma catheter 100 is positioned optimally to penetrate the true lumen. After the plasma catheter 100 is positioned optimally, the surgeon removes the delivery guidewire and initially inserts the plasma guidewire 400 ( Figure 1 The plasma guidewire 400 is inserted into the inner lumen of the inner shaft 14. The surgeon moves the tip portion of the plasma guidewire 400 to the front end of the plasma catheter 100, so that the tip portion of the plasma guidewire 400 protrudes outward from the opening 104a. Then, the surgeon removes the replacement part 60 from the base electrode 30 in the plasma catheter 100 and instead assembles the connecting part 40 onto the base electrode 30. At this time, the lead wire 42 of the connecting part 40 is connected to the cable connector 506, and the connecting part 40 is assembled onto the base electrode 30, thereby establishing conductivity between the plasma catheter 100 and the RF generator 500. The surgeon operates the RF generator 500 to generate a flowing photocorona discharge at the tip plate 403 of the plasma guidewire 400, ablating the CTO.

[0071] Furthermore, for example, after the delivery guidewire is removed, the position of the plasma catheter 100 can be adjusted based on the image from the imaging sensor instead of X-ray imaging by inserting an imaging sensor into the inner lumen of the inner shaft 14.

[0072] As described above, the plasma catheter 100 according to this embodiment has a connecting portion 40 configured to be detachable from the base electrode 30. The RF generator 500 is electrically connected to the base electrode 30 via a lead wire 42 by being attached to the base electrode 30. Therefore, the connecting portion 40 can be removed when conductivity is not required and attached when conductivity is required, allowing the plasma catheter 100 to be used. Thus, as described above, when a surgeon inserts the plasma catheter 100 into the body and performs an operation to advance it within a blood vessel, the lead wire 42 and the first connecting terminal 421 can be removed by detaching the connecting portion 40 from the base electrode 30, providing the same good operability as a catheter without a lead wire. On the other hand, when the front electrode 20 of the plasma catheter 100 reaches the target position and is cauterized, and conductivity is required, the connecting portion 40 is attached to the base electrode 30 and connected to the RF generator 500, thereby establishing energization. That is, by having a detachable connection part 40, it has good operability when no electrical conductivity is required, and can provide a conduit that can conduct electricity when electrical conductivity is required.

[0073] Furthermore, the plasma conduit 100 is configured to allow for the replacement of the connection portion 40 and the replacement portion 60. Figure 3 (A) Since the replacement part 60 does not have the lead wire 42, when the replacement part 60 is assembled to the base electrode 30 to form the intermediate holding part 56, the reduction in operability caused by the lead wire being wound around the holding part 50 and the hollow shaft 10 can be suppressed. Furthermore, since the replacement part 60 has the same sealing part as the connecting part 40, the same waterproof performance as when the connecting part 40 is assembled can be ensured even when the replacement part 60 is assembled.

[0074] Furthermore, in the plasma conduit 100, since the connecting part 40 can be easily disassembled and installed relative to the base electrode 30 by opening and closing the first cover part 441 and the second cover part 442, the connecting part 40 can be quickly assembled to the base electrode 30, thereby enabling the conduit to conduct quickly.

[0075] <Second Implementation>

[0076] Figure 11 This is an explanatory diagram that briefly shows the appearance of the front end holding portion 52A of the plasma conduit 100A according to the second embodiment. The plasma conduit 100A of this embodiment differs from the plasma conduit 100 of the first embodiment in that it includes a terminal support portion 528A capable of supporting the second connecting terminal 422 of the lead 42. In the embodiments described below, structures identical to those in the plasma conduit 100 of the first embodiment are labeled with the same reference numerals, referring to existing descriptions.

[0077] like Figure 11 As shown in (A), in this embodiment, the terminal support portion 528A is formed in a groove shape on the surface of the portion of the tapered portion 522A of the front end holding portion 52A where the spiral groove portion 524 is not formed. Figure 11 (B) shows Figure 11 The figure shows a cross-section of the CC section in (A), and a cross-section of the terminal support portion 528A is shown. As shown in the figure, the width of the cut portion of the terminal support portion 528A on the surface of the tapered portion 522A is narrowed, so that the front end portion of the second connecting terminal 422 will not come out from the surface side of the tapered portion 522A. Figure 11 (C) illustrates the following scenario: In a plasma catheter 100A, a connector 40 is provided, and a second connecting terminal 422 of the lead 42 is supported by a terminal support 528A. The surgeon can support the second connecting terminal 422 by inserting its tip into the terminal support 528A from the front end side.

[0078] According to the plasma conduit 100A of this embodiment, with the connecting part 40 assembled to the base electrode 30, the cable connector 506 ( Figure 1 The second connection terminal 422 is disconnected, and the electrical connection between the second connection terminal 422 and the voltage output device (RF generator 500) is severed. When operating the plasma conduit 100A, the second connection terminal 422 can be fixed to the front end holding part 52A by the terminal support part 528A. Therefore, the second connection terminal 422 of the lead 42 is not fixed and can move freely, thereby suppressing the reduction in operability caused by the lead tangling in the conduit, etc.

[0079] <Third Implementation Method>

[0080] Figure 12 This is an explanatory diagram that briefly shows the appearance of the terminal support portion 528B of the plasma conduit 100B according to the third embodiment. The terminal support portion 528B of this embodiment differs from the terminal support portion 528A of the second embodiment in that it is constructed independently of the front end holding portion 52. That is, the shape of the front end holding portion 52 is the same as that of the first embodiment. Figure 12 As shown in (A), the terminal support portion 528B of this embodiment is mounted on the front end side of the tapered portion 522. Figure 12Figure (B) shows the terminal support portion 528B as viewed from the front end. As shown in the figure, the terminal support portion 528B includes an open-loop first component 528l, an open-loop second component 528c identical to the first component 528l, and a rod-shaped third component 528s connecting the first component 528l and the second component 528c. By inserting the second component 528c into the tapered portion 522, mounting the terminal support portion 528B to the front end gripping portion 52, and inserting the second connecting terminal 422 into the first component 528l, the operator can support the second connecting terminal 422 of the lead 42 by the terminal support portion 528B. Even so, the reduction in operability caused by the lead can be suppressed in the same way as in the second embodiment.

[0081] <Fourth Implementation>

[0082] Figure 13 This is an explanatory diagram showing a simplified structure of the plasma conduit 100C according to the fourth embodiment. Figure 14 This is an explanatory diagram schematically showing the structure of the support portion 542C that provides fixed support for the base electrode 30. Figure 15 This is a simplified illustration of the base end face 44bC of the connecting part 40C. Figure 13 , Figure 14 , Figure 15 Each of the first embodiments Figure 2 , Figure 5 , Figure 9 Correspondingly. The plasma conduit 100C of this embodiment differs from the plasma conduit 100 of the first embodiment in that: the shape of the tapered portion 522C of the front end holding portion 52C, the structure of the connecting portion 40C, and the shape of the support portion 542C of the base end holding portion 54.

[0083] like Figure 13 As shown, the tapered portion 522C does not have the spiral groove portion 524.

[0084] In addition, such as Figure 14 As shown, the support portion 542C is roughly hexagonal prism-shaped, such as... Figure 15As shown, the cross-sectional shape of the hole formed by the base-side recesses 441fC and 442fC of the connecting portion 40C is approximately hexagonal prism, which is generally consistent with that of the support portion 542C. The support portion 542C does not have a protrusion 544 that protrudes from the central axis of the hollow shaft 10 toward the outer periphery of the holding portion 50, but because the support portion 542C is approximately hexagonal prism, it fits into the base-side recesses 441fC and 442fC of the connecting portion 40C. Thus, when the surgeon holds the connecting portion 40C and operates the plasma catheter 100C to rotate it, the rotational force applied to the connecting portion 40C is transmitted to the base electrode 30 through the support portion 542C. Therefore, the free rotation of the connecting portion 40C can be suppressed, and a catheter with good torque transmission can be provided.

[0085] <Fifth Implementation>

[0086] Figure 16 This is an explanatory diagram briefly showing the external structure of the plasma conduit 100D according to the fifth embodiment. The plasma conduit 100D does not have a lead wire 42, but has a connecting portion 40D into which a first connecting terminal 421 of the lead wire 42 is inserted. The connecting portion 40D has an assembly portion that is assembled to the base electrode 30 by inserting the first connecting terminal 421, thereby establishing conduction with the RF generator 500. That is, the connecting portion 40D is assembled to the base electrode 30 by inserting the first connecting terminal 421, and is detached from the base electrode 30 by pulling out the first connecting terminal 421; it is attached and detached from the base electrode 30 in a manner corresponding to the insertion and removal of the first connecting terminal 421. The connecting portion 40D does not cover the base electrode 30. Even so, when conduction is required, conduction can be ensured by connecting the lead wire 42, and when conduction is not required, good operability can be achieved by removing the lead wire 42.

[0087] <Modifications of this embodiment>

[0088] The present invention is not limited to the embodiments described above, and can be implemented in various ways without departing from its spirit, for example, it can also be modified as follows.

[0089] In the above embodiments, a plasma catheter 100 is shown as an example of a catheter, thereby illustrating a plasma guidewire system 1; however, the catheter is not limited to a plasma catheter. It can be configured as a catheter having a front electrode and a base electrode, for example, it can also be configured as a catheter for examination or diagnosis. For example, it can also be configured to include an image sensor.

[0090] In the above embodiment, a structure in which the connecting portion 40 covers the base electrode 30 is shown as an example, but the connecting portion 40 may not cover the base electrode 30. Alternatively, the base electrode 30 may be covered using a structure different from that of the connecting portion 40.

[0091] • In the above embodiment, the plasma conduit 100 is shown to have a structure with the replacement part 60, but it may also not have the replacement part 60.

[0092] In the above embodiments, a hollow tubular base electrode 30 is shown as an example. However, the shape of the base electrode 30 is not limited to the above embodiments and can be formed into various shapes such as rod-shaped, ring-shaped, and sheet-shaped. As described in the above embodiments, by forming the base electrode 30 into a hollow tubular shape and connecting it to the hollow shaft 10, a guide wire can be inserted into the inner cavity of the base electrode 30, or a drug solution can be injected through the inner cavity of the base electrode 30, which is therefore preferred.

[0093] In the above embodiment, an example is shown where the base electrode 30 is electrically connected to the front electrode 20 via the wire loop 16 of the hollow shaft 10, but the electrical connection between the base electrode 30 and the front electrode 20 is not limited to the above embodiment. For example, it can be connected via the braided layer 18 of the hollow shaft 10, or it can be equipped with wires for connecting the base electrodes 30 and 20 in the hollow shaft 10.

[0094] • In the above embodiment, an example is shown in which the connecting part 40 constitutes the intermediate gripping part 56, but the connecting part 40 may not constitute the intermediate gripping part 56.

[0095] The present solution has been described above based on embodiments and variations. However, the embodiments described above are merely methods to facilitate understanding of the present solution and are not intended to limit the present solution. The present solution can be modified and improved without departing from its spirit and the scope of the claims, and the present solution includes its equivalents. Furthermore, if a technical feature is not required to be described in this specification, it can be appropriately deleted.

[0096] Explanation of symbols

[0097] 1—Plasma guide wire system; 10—Hollow shaft; 12—Outer shaft; 14—Inner shaft; 16—Wire coil; 18—Braided layer; 20—Front-end electrode; 30—Base-end electrode; 40, 40C, 40D—Connecting part; 42—Lead wire; 44—Covering part; 44a—Front-end face; 44b, 44bC—Base-end face; 50—Holding part; 52, 52A, 52C—Front-end holding part; 54—Base-end holding part; 56—Intermediate holding part; 60—Replacement part; 70—Connecting part Connectors, 100, 100A, 100B, 100C, 100D—Plasma conduits, 104a—Opening, 400—Plasma guide wire, 403—Front end piece, 421—First connecting terminal, 421a—Contact portion, 422—Second connecting terminal, 441—First cover portion, 441a—First front end face, 441c—Inner surface, 441d—Groove portion for electrode, 441e—Front end side recess, 441f—Base end side recess, 441fC—Base end side recess Part, 441g—Sealing part, 441i—Hole part, 441j—Outer shell, 441k—Inner shell, 442—Second cover part, 442c—Inner surface, 442d—Groove part for electrode, 442e—Front end side recess, 442f, 442fC—Base end side recess, 442g—Sealing part, 442h—Button part, 442i—Hook part, 442j—Outer shell, 442k—Inner shell, 444—Connecting part, 444a—Rotating shaft, 444b, 444c—Rotating part 500—RF generator; 501, 502—terminals; 504, 506—cable connectors; 505—cable; 522, 522A, 522C—tapered portion; 524—spiral groove portion; 526—lead wire recess; 528—front end support portion; 528A, 528B—terminal support portion; 528c—second component; 528l—first component; 528s—third component; 542, 542C—support portion; 544—protrusion.

Claims

1. A catheter, characterized by, Possessing: a hollow shaft; a front-end electrode provided at a front end of the hollow shaft; a base-end electrode provided at a base end of the hollow shaft, electrically connected to the front-end electrode via the hollow shaft; a connection portion configured to be attached to and detached from the base-end electrode, electrically connected to the base-end electrode via a lead wire by being attached to the base-end electrode, and provided with a covering portion that covers the base-end electrode when attached to the base-end electrode; and a gripping portion provided at the base end of the hollow shaft, the connection portion constitutes the gripping portion, the catheter further possesses a replacement portion, the replacement portion is configured to be attached to and detached from the base-end electrode, and constitutes the gripping portion in which the base-end electrode is not electrically connected to the voltage output device when the connection portion is not attached to the base-end electrode.

2. The catheter according to claim 1, wherein the covering portion is configured to be opened and closed, and possesses: a first cover portion having a first connection terminal connected to the lead wire; and a second cover portion connected to the first cover portion by a hinge-structured connecting portion, is attached to the base-end electrode in a closed state in which the base-end electrode is sandwiched by the first cover portion and the second cover portion, is capable of being detached from the base-end electrode in an open state, the first connection terminal is disposed at a position at which the base-end electrode is contacted when the connection portion is attached to the base-end electrode.

3. The catheter according to claim 2, wherein at least either one of the first cover portion and the second cover portion possesses an electrode groove portion in which the base-end electrode is fitted, the electrode groove portion is disposed at a position at which the first connection terminal is contacted to the base-end electrode when the connection portion is attached to the base-end electrode.

4. The catheter according to claim 3, wherein at least either one of the first cover portion and the second cover portion possesses a seal portion that surrounds an outer periphery of the electrode groove portion.

5. The catheter according to any one of claims 1 to 4, wherein the gripping portion has a front-end gripping portion disposed at a front end of the gripping portion, a base-end gripping portion disposed at a base end of the gripping portion, and an intermediate gripping portion disposed between the front-end gripping portion and the base-end gripping portion, the connection portion and the replacement portion each constitute the intermediate gripping portion when attached to the base-end electrode.

6. The catheter according to claim 5, wherein the base-end gripping portion possesses a support portion, the support portion is provided at a front end side of the base-end gripping portion, and fixedly supports the base-end electrode, the support portion has a protrusion portion that protrudes in a direction from a central axis of the hollow shaft toward an outer periphery of the gripping portion, the intermediate gripping portion possesses a recess portion in which the support portion of the base-end gripping portion is fitted.

7. The catheter according to claim 5, wherein the front-end gripping portion possesses a tapered portion that is tapered toward a front end thereof, the tapered portion has a helical groove portion that is formed in a helical groove shape on a surface.

8. The catheter according to claim 5, wherein In the case where the intermediate holding portion is configured by the above connection portion, the front end holding portion is capable of supporting the lead along the surface of the front end holding portion, and has a lead recess on the surface thereof into which the lead is capable of being fitted.

9. The catheter according to claim 5, wherein The lead has a second connection terminal disposed at the front end thereof and capable of being electrically connected to the voltage output device, The catheter has a terminal support portion capable of supporting the second connection terminal at the front end holding portion.

Images