Medical catheter

Abstract

The invention provides a medical catheter. The medical catheter comprises a catheter body, a first electrode, a second electrode and a fixing structure, the catheter body comprises an inner tube and an outer tube, and a spacing cavity used for forming a saline water conveying channel is formed between the outer tube and the inner tube; the outer tube comprises a connecting section located at the far end, the connecting section is sequentially sleeved with the first electrode and the second electrode in the axial direction, the connecting section is provided with a plurality of through holes penetrating through the side wall, and saline water holes of the first electrode and the second electrode are communicated with the interval cavity through the through holes; the fixing structure is fixed in the inner tube and used for at least fixing a pull wire so that the pull wire can control bending of the far end of the catheter body, and the pull wire does not exceed the first electrode and the second electrode in the axial direction of the catheter body. The catheter is easy to assemble, poor insulation between the electrodes is avoided, the electrode cost is reduced, the flat attaching capacity of the two electrodes is improved, and the targeted ablation precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a medical catheter. Background Art

[0002] Vascular interventional technology can effectively treat cardiovascular, peripheral vascular, and tracheal diseases, with the advantages of less trauma, low reaction, and fast recovery. It also has targeted characteristics, which can effectively treat some patients who cannot tolerate surgery or lose the opportunity for surgery or are drug-resistant. Blind ablation has problems such as excessive ablation. Targeted denervation ablation mainly achieves the therapeutic effect by blocking the nerve bundles around blood vessels or trachea through targeted deep tissue ablation, and the ablation area is relatively small. For example, radiofrequency denervation ablation of the lungs to treat chronic obstructive pulmonary disease, and sympathetic denervation through the renal artery to treat hypertension, etc. Targeted ablation can be implemented more accurately and effectively, improving the safety and effectiveness of ablation.

[0003] Most catheters on the market currently provide single-electrode targeted ablation or multi-electrode blind ablation. Targeted ablation with two or more electrodes can further improve targeting accuracy. Existing bipolar ablation catheters can achieve targeted ablation, but there is a risk of poor insulation, high electrode cost, and difficulty in assembly. Summary of the invention

[0004] An object of the present invention is to provide a medical catheter to solve one or more problems in the prior art.

[0005] To solve the above problems, the present invention provides a medical catheter, comprising: a catheter body, a first electrode, a second electrode and a fixing structure;

[0006] The catheter body comprises an inner tube and an outer tube, wherein the outer tube is coaxially sleeved outside the inner tube and has a spacer cavity between the outer tube and the inner tube, and the spacer cavity constitutes a saline delivery channel;

[0007] The outer tube includes a connecting section at the distal end, the first electrode and the second electrode are sequentially sleeved on the connecting section along the axial direction of the catheter body, and the first electrode and the second electrode each have a plurality of saline holes, the connecting section has a plurality of through holes penetrating the side wall, and the plurality of saline holes are connected to the spacer cavity through the plurality of through holes;

[0008] The fixing structure is fixed in the inner tube and is used to fix at least a pull wire, so that the pull wire can control the bending of the distal end of the catheter body and the fixing structure does not exceed the first electrode and the second electrode in the axial direction of the catheter body.

[0009] Optionally, in the medical catheter, the medical catheter further includes a plurality of sensing elements, and the plurality of sensing elements are fixed in the inner tube via the fixing structure.

[0010] Optionally, in the medical catheter, the fixed structure is a cylindrical body whose outer contour size matches the inner diameter of the inner tube, and the cylindrical body has a plurality of positioning grooves, which are arranged in sequence around the axis of the cylindrical body; the distal end of the pull wire and the plurality of sensing elements are respectively fixed in one of the positioning grooves.

[0011] Optionally, in the medical catheter, the cylindrical body is fixed in the inner tube by injecting glue into the inner tube, and the injected glue covers the cylindrical body so that the distal ends of the plurality of sensing elements and the pull wire are fixed to the cylindrical body.

[0012] Optionally, in the medical catheter, the fixed structure includes a plurality of tubular bodies, and the distal ends of a plurality of the sensing elements and the pull wires are respectively fixed in one of the tubular bodies; the plurality of tubular bodies are connected as a whole, and the overall outer contour size matches the inner diameter of the inner tube.

[0013] Optionally, in the medical catheter, the plurality of tubular bodies are bonded together and fixed in the inner tube by injecting glue into the inner tube, and the glue fills the inner cavity of each tubular body so that the distal ends of the plurality of sensing elements and the pull wires are fixed in the corresponding tubular bodies.

[0014] Optionally, in the medical catheter, the conductive wires of the first electrode and the second electrode pass through the connecting section and the side wall of the inner tube and extend into the inner tube, and the positions of the conductive wires of the first electrode and the second electrode in the inner tube and the position of the distal end of the pull wire are distinguished by the fixed structure.

[0015] Optionally, in the medical catheter, the side wall of the outer tube is a multi-layer structure, including a polymer inner layer, a metal braided layer and a polymer outer layer stacked in sequence from inside to outside, and the metal braided layer of the connecting section used to sleeve the first electrode and the second electrode is a spiral braided structure.

[0016] Optionally, in the medical catheter, the outer tube further includes a main body segment, the connecting segment is connected to the distal end of the main body segment, the connecting segment is a single-lumen tube, the main body segment is a multi-layer structure, and the connecting segment and the main body segment are smoothly transitionally connected.

[0017] Optionally, in the medical catheter, the main body section includes a polymer inner layer, a metal braided layer and a polymer outer layer stacked sequentially from inside to outside.

[0018] In summary, the medical catheter provided by the present invention comprises: a catheter body, a first electrode, a second electrode and a fixing structure; the catheter body comprises an inner tube and an outer tube, the outer tube is coaxially sleeved outside the inner tube, and has a spacer cavity between the outer tube and the inner tube, and the spacer cavity constitutes a saline delivery channel; the outer tube comprises a connecting section located at the distal end, the first electrode and the second electrode are sequentially sleeved on the connecting section along the axial direction of the catheter body, and the first electrode and the second electrode both have a plurality of saline holes, the connecting section has a plurality of through holes penetrating the side wall, and the plurality of saline holes are connected to the spacer cavity through the plurality of through holes; the fixing structure is fixed in the inner tube, and is used to at least fix the pull wire, so that the pull wire can control the bending of the distal end of the catheter body, and the fixing structure does not exceed the first electrode and the second electrode in the axial direction of the catheter body. Compared with the prior art, the medical catheter provided by the present invention has the following beneficial effects:

[0019] (1) The first electrode and the second electrode can be arranged in sequence in the axial direction, which is easy to assemble and will not cause poor insulation due to contact between the two electrodes;

[0020] (2) The first electrode and the second electrode can be ordinary ring electrodes, which can greatly reduce the overall cost of the catheter;

[0021] (3) Since the fixing structure does not extend beyond the first electrode and the second electrode in the axial direction of the catheter body, it is equivalent to that the fixing structure is arranged in the annular cavity extending from the distal end of the first electrode to the proximal end of the second electrode. Such a design helps to shorten the rigid straight section of the catheter tip and improve the ability of the two electrodes to lie flat in the blood vessel, thereby improving the accuracy of targeted ablation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0023] Figure 1 A schematic diagram of the working state of the medical catheter provided by an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the distal structure of a medical catheter provided in Embodiment 1 of the present invention;

[0025] Figure 3 This is a schematic diagram of the assembly of the components inside the inner tube in the first embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the assembly of the outer tube, the inner tube and the fixing structure in the first embodiment of the present invention;

[0027] Figure 5This is a schematic diagram of the structure of the outer tube in Embodiment 1 of the present invention;

[0028] Figure 6 This is a schematic diagram of the assembly of the components inside the inner tube in the second embodiment of the present invention;

[0029] Figure 7 A schematic diagram of the distal structure of a medical catheter provided in Embodiment 3 of the present invention;

[0030] The descriptions of the reference numerals are as follows:

[0031] 1-electrode; 2-catheter body; 3-handle; 4-saline connector; 5-leather strap; 6-infusion pump; 7-saline; 8-radiofrequency instrument; 9-three-dimensional system; 10-fixed structure; 11-first electrode; 12-second electrode;

[0032] 100- compartment cavity; 101- pull wire; 102- magnetic positioning sensor; 103- temperature sensor;

[0033] 21-inner tube; 22-outer tube;

[0034] 111 - first wire; 121 - second wire;

[0035] 201- polymer outer layer; 202- metal braided layer; 203- polymer inner layer;

[0036] 221-connecting section; 222-main section. DETAILED DESCRIPTION

[0037] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0038] As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features, "one end" and "the other end" and "the proximal end" and "the distal end" generally refer to two corresponding parts, which are not only included in the present application document, "proximal end" and "distal end" are the relative orientation, relative position, and direction of the elements or actions relative to each other from the perspective of the doctor using the medical device, although "proximal end" and "distal end" are not restrictive, but "proximal end" generally refers to the end of the medical device close to the doctor during normal operation, and "distal end" generally refers to the end that first enters the patient's body. In addition, as used in the present invention, "installed", "connected", "connected", and one element "set" on another element should be understood in a broad sense, usually only indicating that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any orientation such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise.

[0039] [Example 1]

[0040] See also Figure 1, an embodiment of the present invention provides a medical catheter, the distal end of which has two electrodes 1 arranged in sequence along the axial direction. After the sheath is guided into place, the medical catheter can apply energy to the target tissue for stimulation or ablation. The stimulation types include monopolar stimulation and bipolar stimulation, and the ablation types also include monopolar ablation and bipolar ablation. The distal end of the catheter has a bending deformation function, the proximal end of the catheter is connected to the three-dimensional system 9, the radiofrequency instrument 8, etc. through a tail line, and the proximal end of the catheter is provided with a saline connector 4, which cooperates with the perfusion pump 6 through a leather strap 5 to deliver saline 7 to the catheter lumen. During surgery, invasive blood pressure monitoring is required, and the radiofrequency instrument 8 calculates and processes the monitored physiological signals and classifies them, issues instructions to the target point that needs to be ablated, and outputs an ablation signal to the electrode 1 at the distal end of the catheter to achieve the purpose of ablation. If the target point does not belong to the ablation category, the ablation signal is cut off to avoid stenosis. It should be noted that the catheter body 2 can be bent under the action of the pull wire, so the axial direction of the catheter body 2 is not limited to a straight line, but refers to the extension direction of the catheter body 2. The axial direction of the catheter body 2 should be understood to be able to bend as the catheter body 2 bends.

[0041] Specifically, please combine Figures 2 to 4 The medical catheter comprises: a catheter body 2, a first electrode 11, a second electrode 12 and a fixing structure 10; the catheter body 2 comprises an inner tube 21 and an outer tube 22, the outer tube 22 is coaxially sleeved outside the inner tube 21, and a spacer cavity 100 is provided between the outer tube 22 and the inner tube 21, and the spacer cavity 100 constitutes a saline delivery channel; the outer tube 22 comprises a connecting section 221 at a distal end, the first electrode 11 and the second electrode 12 are sequentially sleeved on the connecting section 221 along the axial direction of the catheter body 2, and the first electrode 11 and the second electrode 12 both have a plurality of saline holes, the connecting section 221 has a plurality of through holes penetrating the side wall, and the plurality of saline holes are connected to the spacer cavity 100 through the plurality of through holes; the fixing structure 10 is fixed in the inner tube 21, and is used to fix at least a pull wire 101, so that the pull wire 101 can control the bending of the distal end of the catheter body 2, and the fixing structure 10 does not exceed the first electrode 11 and the second electrode 12 in the axial direction of the catheter body 2.

[0042] It should be noted here that, generally, an electrode includes an electrode body and a wire. In the present application, both the first electrode 11 and the second electrode 12 are ring electrodes. Therefore, it can be understood that the first electrode 11 and the second electrode 12 in the present application are sequentially sleeved on the connecting section 221 along the axial direction of the catheter body 2, which means that the electrode bodies of the first electrode 11 and the second electrode 12 except the wire are sequentially sleeved on the connecting section 221 along the axial direction of the catheter body 2, and the first wire 111 and the second wire 121 extend into the inner tube 21 after passing through the side wall of the connecting section 221 of the outer tube 22 and the side wall of the inner tube 21, and the positions of the first wire 111 and the second wire 121 in the inner tube 21 and the distal end of the pull wire 101 are preferably distinguished by the fixing structure 10. In addition, the first wire 111 and the second wire 121 pass through the proximal end of the catheter body 2 along the inner cavity of the inner tube 21 and are connected to an external device, such as a radiofrequency instrument 8, a three-dimensional system 9, etc.

[0043] The two electrodes of the existing bipolar ablation catheter are connected radially by an insulating member. This connection method makes it possible for the two electrodes to come into contact during use due to bending of the catheter, etc.; and because the electrode near the distal end adopts a special structural design, with a head and a rod, the head is provided with a saline hole, and the rod is provided for the electrode near the proximal end, the two need to be connected by an insulating member of a special structure, which makes assembly difficult and the cost high; in addition, when fixing the pull wire, in order to avoid affecting the saline injection from the saline hole in the head of the electrode near the distal end, the axial size of the electrode head is increased during design so that a fixing member for fixing the pull wire can be provided, which inevitably increases the axial size of the distal stiff section, making the stiff section at the catheter tip longer.

[0044] In the medical catheter provided by the present invention, the first electrode 11 and the second electrode 12 can be sequentially sleeved in the axial direction, which is easy to assemble, and there is no poor insulation between the two electrodes due to contact; in addition, the first electrode 11 and the second electrode 12 can be ordinary ring electrodes, which can greatly reduce the overall cost of the catheter; furthermore, since the spacing cavity 100 between the inner tube 21 and the outer tube 22 is isolated from the inner cavity of the inner tube 21, the setting of the fixing structure 10 in the inner cavity of the inner tube 21 will not affect the transportation of saline by the spacing cavity 100 to the saline holes of the first electrode 11 and the second electrode 12, so there is no need to specially increase the head The axial length of the end is used for the setting of the fixing structure 10. The fixing structure 10 can be set in an annular cavity extending from the distal end of the first electrode 11 to the proximal end of the second electrode 12, so that the fixing structure 10 does not exceed the first electrode 11 and the second electrode 12 in the axial direction of the catheter body 2, that is, the distal end of the fixing structure 10 does not exceed the distal end of the first electrode 11, and the proximal end of the fixing structure 10 does not exceed the proximal end of the second electrode 12. Compared with the existing bipolar ablation catheter, such a design can shorten the rigid straight section of the catheter head end, improve the ability of the two electrodes to fit flat in the blood vessel, thereby improving the accuracy of targeted ablation.

[0045] Specifically, in this embodiment, the distance between the first electrode 11 and the second electrode 12 can be maintained at 0.3-0.8 mm, and the rigid segment is reduced from about 11 mm of the original catheter to about 7 mm. The diameter of the renal artery is usually about 4-6 mm, and the catheter can only be placed obliquely or flatly in the renal artery. The electrode distance and the rigid segment are too long, resulting in the second electrode 12 being unable to be attached to the vascular tissue and being suspended in the blood. Therefore, the shortening of the rigid segment helps to improve the ability of the two electrodes to be flat in the blood vessel, realize bipolar stimulation and bipolar ablation with the two electrodes attached at the same time, and improve the accuracy of targeted ablation.

[0046] In addition, the medical catheter provided in the embodiment of the present invention may also include a plurality of sensing elements, such as a magnetic positioning sensor, a temperature sensor, etc., and the plurality of sensing elements are also fixed in the inner tube 21 through the fixing structure 10. In order to facilitate the fixing of the pull wire 101, the sensing elements, etc., in this embodiment, Figure 3 As shown, the fixing structure 10 is a cylindrical body 10 whose outer contour size matches the inner diameter of the inner tube 21, and the cylindrical body 10 has a plurality of positioning grooves, which are arranged in sequence around the axis of the cylindrical body 10; the distal end of the pull wire 101 and the plurality of sensing elements are fixed in one of the positioning grooves respectively. The present application does not impose any particular limitation on the shape of the positioning groove.

[0047] In a specific embodiment, Figure 3As shown, the cylindrical body 10 has four positioning grooves, one of which is used to set the magnetic positioning sensor 102, one is used to set the temperature sensor 103, one is used to fix the distal end of the pull wire 101, and another is used to pass the first wire 111 and the second wire 121. The setting of the multiple positioning grooves of the cylindrical body 10 is convenient for fixing the distal end of the pull wire 101 and each sensing element, and on the other hand, it makes the pull wire 101 and the second electrode 12 and the wire of the second electrode 12 not interfere with each other when passing through the inner cavity of the inner tube 21, and will not be entangled, and the test will not be affected by the contact between the sensing elements. Preferably, the positioning groove for fixing the distal end of the positioning wire and the positioning groove for passing the first wire 111 and the second wire 121 are two positioning grooves symmetrically arranged about the axis of the cylindrical body 10, so as to ensure that the pull wire 101 will not be entangled with the electrode wire when the distal end of the catheter is bent by the pull wire 101.

[0048] In order to facilitate fixation, preferably, the columnar body 10 is fixed in the inner tube 21 by injecting glue in the inner tube 21, and the injected glue covers the columnar body 10 so that the distal ends of the plurality of sensing elements and the pull wire 101 are fixed to the columnar body 10. Specifically, when injecting glue into the inner tube 21, the glue penetrates between the columnar body 10 and the inner tube 21 to achieve fixation between the columnar body 10 and the inner tube 21, and penetrates into each of the positioning grooves to achieve fixation between the plurality of sensing elements and the distal ends of the pull wire 101 and the columnar body 10. Since the axial length of the positioning groove is limited, in order to ensure the connection strength between the distal end of the pull wire 101 and the cylindrical body 10, the distal end of the pull wire 101 can also be simultaneously fixed by other connection methods. For example, the distal end of the pull wire 101 is welded to a connecting piece, and the distal end of the connecting piece is arranged in the positioning groove to achieve the fixation of the distal end of the connecting piece in the positioning groove. The distal end fixing method of the pull wire 101 does not constitute a limitation to the present application.

[0049] As mentioned above, the distal end of the medical catheter provided in the embodiment of the present invention has a bending and deformation function. To this end, in this embodiment, the side wall of the outer tube 22 is a multi-layer structure, such as Figure 5As shown, it includes a polymer inner layer 203, a metal braided layer 202 and a polymer outer layer 201 stacked in sequence from the inside to the outside, and the metal braided layer 202 at the distal end of the outer tube 22 (at least including the part of the connecting section 221 for sleeve the first electrode 11 and the second electrode 12) is a spiral braided structure, which can meet the functions of wire threading and bending control, and the braiding method of the metal braided layer 202 at the proximal end of the outer tube 22 provides a higher support force and twist control ability for the catheter. When the pull wire 101 moves axially toward the proximal end due to traction, the distal end of the catheter bends.

[0050] For further information, see Figure 1 The medical catheter provided in this embodiment may further include a handle 3, the proximal end of the catheter body 2 is connected to the handle 3, the handle 3 includes a handle body and a control member arranged on the handle body, the proximal end of the pull wire 101 is connected to the control member, and the control member controls the axial movement of the pull wire 101 by rotation and / or movement, and a tail wire plug (not shown) may also be provided at the proximal end of the handle 3, the first wire 111, the second wire 121 and the wires of each sensing element are connected to the tail wire plug at the proximal end of the handle 3 after passing through the inner tube 21 and the handle 3 in sequence, and are connected to an external device through the tail wire plug.

[0051] In addition, the medical catheter provided in this embodiment may also include a neutral electrode. When the medical catheter is in working state, the neutral electrode is attached to the surface of the skin to form a stimulation circuit / ablation circuit with the first electrode 11 and / or the second electrode 12, thereby providing more stimulation and ablation modes. For example, the first electrode 11 and the second electrode 12 may cooperate with each other to achieve bipolar stimulation or bipolar ablation, and when the ablation depth is required, the first electrode 11 and the second electrode 12 may be used to form an ablation circuit with the neutral electrode respectively.

[0052] [Example 2]

[0053] Different from the first embodiment, in this embodiment, Figure 5 As shown, the fixing structure 10 includes a plurality of tubular bodies, and the distal ends of the plurality of sensing elements and the pull wire 101 are fixed to a tubular body respectively; the plurality of tubular bodies are connected as a whole, and the overall outer contour size matches the inner diameter of the inner tube 21. Preferably, the plurality of tubular bodies are bonded as a whole and fixed in the inner tube 21 by injecting glue into the inner tube 21, and the glue fills the inner cavity of each tubular body so that the distal ends of the plurality of sensing elements and the pull wire 101 are fixed in the corresponding tubular body.

[0054] In the first embodiment, the columnar body 10 provides a positioning function, but the manufacturing process involves multiple steps of welding and bonding, which is relatively complicated to manufacture and the cost of the columnar body 10 is also higher. In this embodiment, the columnar body 10 structure is discarded, and multiple tubular bodies are used to fix them separately, and the multiple tubular bodies are bonded together as a whole, which greatly reduces the cost and the difficulty of catheter assembly while retaining the original function.

[0055] In this embodiment, since the distal end of the pull wire 101 is fixed in the tubular body, the tubular body has a greater length in the axial direction of the inner tube 21 relative to the positioning groove, so in this embodiment, the distal end of the pull wire 101 can be firmly connected by injecting glue. Other manufacturing processes are the same as those in the first embodiment.

[0056] [Example 3]

[0057] In the first embodiment, the connecting section 221 of the outer tube 22 and the rest of the outer tube 22 can be integrally formed and both adopt a three-layer structure, and only the metal braided layer at the distal end thereof needs to adopt a spiral braided structure.

[0058] Different from the first embodiment, in this embodiment, Figure 7 As shown, the connecting section 221 is a single-lumen tube, and the outer tube 22 also includes a main body section 222 (i.e., the remaining part of the outer tube 22 mentioned above). The connecting section 221 is connected to the distal end of the main body section 222. The main body section 222 is a multi-layer structure. The connecting section 221 is smoothly transitioned and connected to the main body section 222. The welding process can be high-frequency welding, which helps to make the welding position transition smooth and eliminate appearance problems such as gaps.

[0059] Preferably, the main body section 222 includes a polymer inner layer 203, a metal braided layer 202 and a polymer outer layer 201 stacked sequentially from the inside to the outside. The distal end of the main body section 222 satisfies the bending control function, and the proximal end of the main body section 222 provides a higher support force and twist control capability for the catheter.

[0060] In the first embodiment, since the outer tube 22 contains braided wires between the inner and outer layers, after the first electrode 11 and the second electrode 12 are sleeved on the connecting section 221, it is necessary to punch holes in the connecting section 221 and the inner tube 21 so that the wires of the first electrode 11 and the second electrode 12 can pass through the inner cavity of the inner tube 21. Punching holes can easily expose the metal braided wires, causing problems such as catheter leakage or wire damage. In this embodiment, a section of single-lumen tube without braided wires is welded at the distal end of the main section 222 of the outer tube 22, and a ring electrode is sleeved on the single-lumen tube, so punching holes is also simpler and safer.

[0061] In summary, the medical catheter provided by the embodiment of the present invention includes: a catheter body, a first electrode, a second electrode and a fixing structure; the catheter body includes an inner tube and an outer tube, the outer tube is coaxially sleeved outside the inner tube, and has a spacing cavity between the outer tube and the inner tube, and the spacing cavity constitutes a saline delivery channel; the outer tube includes a connecting section located at the distal end, the first electrode and the second electrode are sequentially sleeved on the connecting section along the axial direction of the catheter body, and the first electrode and the second electrode both have a plurality of saline holes, the connecting section has a plurality of through holes penetrating the side wall, and the plurality of saline holes are connected to the spacing cavity through the plurality of through holes; the fixing structure is fixed in the inner tube, and is used to at least fix a pull wire, so that the pull wire can control the bending of the distal end of the catheter body, and the fixing structure does not exceed the first electrode and the second electrode in the axial direction of the catheter body. In the medical catheter provided by the present invention, the first electrode and the second electrode can be sequentially sleeved in the axial direction, which is easy to assemble and will not cause poor insulation due to contact between the two electrodes; the first electrode and the second electrode can be ordinary ring electrodes, which can greatly reduce the overall cost of the catheter; because the fixing structure does not exceed the first electrode and the second electrode in the axial direction of the catheter body, it is equivalent to that the fixing structure is arranged in the annular cavity extending from the distal end of the first electrode to the proximal end of the second electrode. Such a design helps to shorten the rigid straight section of the catheter head end and improve the ability of the two electrodes to be flat in the blood vessel, thereby improving the accuracy of targeted ablation.

[0062] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other. In addition, the different parts between the various embodiments can also be used in combination with each other, and the present invention is not limited to this.

[0063] In addition, it should be recognized that although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the scope of protection of the technical solution of the present invention.

Claims

1. A medical catheter, characterized in that: include: A catheter body, a first electrode, a second electrode, and a fixing structure; The catheter body comprises an inner tube and an outer tube, wherein the outer tube is coaxially sleeved outside the inner tube and has a spacer cavity between the outer tube and the inner tube, and the spacer cavity constitutes a saline delivery channel; The outer tube includes a connecting section at the distal end, the first electrode and the second electrode are sequentially sleeved on the connecting section along the axial direction of the catheter body, and the first electrode and the second electrode each have a plurality of saline holes, the connecting section has a plurality of through holes penetrating the side wall, and the plurality of saline holes are connected to the spacer cavity through the plurality of through holes; The fixing structure is fixed in the inner tube and is used to fix at least a pull wire so that the pull wire can control the bending of the distal end of the catheter body, and the fixing structure does not exceed the first electrode and the second electrode in the axial direction of the catheter body.

2. The medical catheter according to claim 1, characterized in that The medical catheter further includes a plurality of sensing elements, and the plurality of sensing elements are fixed in the inner tube through the fixing structure.

3. The medical catheter according to claim 2, characterized in that The fixing structure is a cylindrical body whose outer contour size matches the inner diameter of the inner tube. The cylindrical body has a plurality of positioning grooves, and the plurality of positioning grooves are arranged in sequence around the axis of the cylindrical body; the distal end of the pull wire and the plurality of sensing elements are respectively fixed in one of the positioning grooves.

4. The medical catheter according to claim 3, characterized in that The columnar body is fixed in the inner tube by injecting glue into the inner tube, and the injected glue covers the columnar body so that the sensing elements and the distal ends of the pull wires are fixed to the columnar body.

5. The medical catheter according to claim 1, wherein: The fixing structure comprises a plurality of tubular bodies, and the distal ends of a plurality of the sensing elements and the pull wires are fixed in one of the tubular bodies respectively; the plurality of tubular bodies are connected as a whole, and the overall outer contour size matches the inner diameter of the inner tube.

6. The medical catheter according to claim 5, characterized in that The plurality of tubular bodies are bonded together and fixed in the inner tube by injecting glue into the inner tube, and the glue fills the inner cavity of each tubular body so that the distal ends of the plurality of sensing elements and the pull wires are fixed in the corresponding tubular bodies.

7. The medical catheter according to claim 1, wherein: The conductive wires of the first electrode and the second electrode extend into the inner tube through the connecting section and the side wall of the inner tube, and the positions of the conductive wires of the first electrode and the second electrode in the inner tube and the position of the distal end of the pull wire are distinguished by the fixing structure.

8. The medical catheter according to claim 1, wherein: The side wall of the outer tube is a multi-layer structure, including a polymer inner layer, a metal braided layer and a polymer outer layer stacked in sequence from the inside to the outside, and the metal braided layer of the connecting section used to sleeve the first electrode and the second electrode is a spiral braided structure.

9. The medical catheter according to claim 1, wherein: The outer tube also includes a main body section, the connecting section is connected to the distal end of the main body section, the connecting section is a single-lumen tube, the main body section is a multi-layer structure, and the connecting section and the main body section are smoothly transitionally connected.

10. The medical catheter according to claim 9, characterized in that The main body section comprises a polymer inner layer, a metal braided layer and a polymer outer layer which are sequentially stacked from the inside to the outside.

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