Flexible ablation catheter and ablation system

Abstract

The utility model provides a flexible ablation catheter and an ablation system. The flexible ablation catheter comprises a catheter main body and a flexible part, the flexible part comprises a flexible single-cavity tube and an electrode assembly, and the electrode assembly is connected to the far end of the catheter body through the flexible single-cavity tube; the flexible portion further comprises a spring structure, the spring structure is limited to stretch out and draw back in the axial direction and allowed to be bent, the spring structure extends in the flexible single-cavity tube in the axial direction of the flexible single-cavity tube, and the outer diameter of the spring structure is matched with the inner diameter of the flexible single-cavity tube.

Description

Technical Field

[0001] The utility model relates to the field of medical technology, in particular to a flexible ablation catheter and an ablation system. Background Art

[0002] Hypertrophic cardiomyopathy is an autosomal dominant hereditary disease, with the main symptoms of dyspnea, angina pectoris and palpitations, which can cause sudden death in severe cases. The epidemiological incidence rate is 0.2%, of which 60% are obstructive. For patients with obstructive type of hypertrophic cardiomyopathy who are ineffective with drug treatment and have severe left ventricular outflow tract obstruction, surgical treatment is required. The traditional surgical treatment method is ventricular septal myectomy, which has the disadvantages of high surgical difficulty, large patient trauma and long postoperative recovery period. Therefore, ventricular septal ablation surgery, which has the advantages of relatively low surgical difficulty, small patient trauma, fast postoperative recovery and good prognosis, has become a research hotspot in recent years. However, traditional ablation equipment has the disadvantages of insufficient ablation depth and difficulty in accurately reaching the lesion for ablation of hypertrophic myocardial infarction lesions.

[0003] Due to the limitations of the heart structure and the principle of catheter angle adjustment, it is difficult to ablate the right ventricle vertically against the ventricular septum to achieve the best volume reduction effect in traditional transfemoral septal ablation surgery. It is necessary to perform atrial septal puncture, enter the left ventricle with the assistance of an adjustable curved sheath, adjust the front end of the catheter to bend vertically against the hypertrophic area for ablation in order to achieve the best ablation effect. Compared with the right ventricle in place method, this procedure will prolong the operation time, increase surgical trauma, and there are more important conduction bundles in the left ventricular septum endocardium, so the surgical risk is higher. At the same time, the ablation depth of ordinary radiofrequency ablation catheters is smaller than the thickness of the ventricular septum in patients with ventricular septal hypertrophy, so there will be a phenomenon that the ablation depth is not enough, resulting in unsatisfactory surgical results. Utility Model Content

[0004] The purpose of the utility model is to provide a flexible ablation catheter and an ablation system to solve one or more problems existing in the prior art.

[0005] In order to solve the above problems, the utility model provides a flexible ablation catheter, comprising: a catheter body and a flexible part;

[0006] The flexible portion includes a flexible single-lumen tube and an electrode assembly, and the electrode assembly is connected to the distal end of the catheter body through the flexible single-lumen tube.

[0007] Optionally, in the flexible ablation catheter, the flexible part also includes a spring structure, the spring structure is restricted in axial expansion and contraction and allowed to bend, the spring structure is arranged in the flexible single-lumen tube and extends along the axial direction of the flexible single-lumen tube, and the outer diameter of the spring structure matches the inner diameter of the flexible single-lumen tube.

[0008] Optionally, in the flexible ablation catheter, the distal end of the catheter body has a first reduced diameter section, the proximal end of the spring structure is sleeved on the first reduced diameter section and fixed by bonding, and the distal end of the spring structure is fixed in the flexible single-lumen tube by bonding or glue injection.

[0009] Optionally, in the flexible ablation catheter, the length of the spring structure is 1 / 2 to 9 / 10 of the total length of the flexible portion, and the wire diameter of the spring structure is 0.1 mm to 0.5 mm.

[0010] Optionally, in the flexible ablation catheter, the flexible portion also includes a hard tube segment, the electrode assembly is connected to the distal end of the flexible single-lumen tube via the hard tube segment, the total length of the flexible portion is 80 cm to 150 cm, and the length of the hard tube segment is 4 mm to 7 mm.

[0011] Optionally, in the flexible ablation catheter, the inner cavity of the hard tube section is filled by glue injection.

[0012] Optionally, in the flexible ablation catheter, the flexible single-lumen tube is made of a medical tubing material of a soft polymer or a thermoplastic elastomer, and the hard tube segment is made of a medical tubing material of a hard polymer.

[0013] Optionally, in the flexible ablation catheter, the flexible portion further comprises a wire protection tube and a saline tube, and the wire protection tube is used for passing the wire of the electrode assembly; wherein,

[0014] The saline tube is passed through the flexible single-lumen tube and extends to pass through the proximal end of the catheter body. The wire protection tube is passed through the flexible single-lumen tube and extends to be fixed in the catheter body. At least the parts of the saline tube and the wire protection tube that pass through the flexible single-lumen tube are flexible tubes.

[0015] Optionally, in the flexible ablation catheter, the electrode assembly includes a needle electrode, a head electrode and a ring electrode, the head electrode is connected to the distal end of the flexible single-lumen tube, the needle electrode can be movably inserted into the saline tube and the distal end of the needle electrode can extend out of the head electrode, the ring electrode is sleeved on the flexible single-lumen tube, and the wires of the ring electrode and the head electrode are inserted into different wire protective tubes.

[0016] Optionally, in the flexible ablation catheter, the proximal end of the head electrode has a second reduced diameter section, and the proximal end of the flexible single-lumen tube is sleeved on the second reduced diameter section and fixed by bonding.

[0017] The utility model also provides an ablation system, comprising: a three-dimensional curved sheath and a flexible ablation catheter as described in any of the preceding items, wherein the three-dimensional curved sheath is used to guide the flexible ablation catheter into place, and the shape of the flexible ablation catheter can change in accordance with the shape of the three-dimensional curved sheath.

[0018] In summary, the flexible ablation catheter and ablation system provided by the present invention have the following beneficial effects compared with the prior art:

[0019] (1) The hardness of the distal end of the catheter is reduced, which allows for better coordination with the three-dimensional curved sheath, thereby achieving ablation of hypertrophic ventricular septum in the right ventricle;

[0020] (2) The bendable but incompressible nature of the spring structure provides better support for the needle electrode when it penetrates the myocardium, solving the problem of the catheter’s inability to penetrate the myocardium due to insufficient support at the distal end, which is too soft. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Those skilled in the art will appreciate that the drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0022] Figure 1 Schematic diagram of an ablation catheter in combination with a three-dimensional curved sheath entering the right ventricle through the inferior vena cava to ablate the ventricular septum;

[0023] Figure 2 A schematic diagram of the overall structure of the flexible ablation catheter provided in Embodiments 1 to 3 of the present utility model;

[0024] Figure 3 The flexible ablation catheter provided in the first embodiment of the utility model Figure 2 Schematic diagram of the internal structure of region A shown in;

[0025] Figure 4 The flexible ablation catheter provided in the second embodiment of the utility model Figure 2 Schematic diagram of the internal structure of region A shown in;

[0026] Figure 5 The flexible ablation catheter provided in the third embodiment of the utility model Figure 2 Schematic diagram of the internal structure of region A shown in;

[0027] In the attached figure:

[0028] 1-stereoscopic curved sheath; 2-ablation catheter; 3-right ventricle; 4-ventricular septum;

[0029] 10-catheter body; 20-flexible portion; 30-handle;

[0030] 201-flexible single-lumen tube; 202-needle electrode; 203-head electrode; 204-ring electrode; 205-wire protective tube; 206-saline tube; 207-spring structure; 208-hard tube segment. DETAILED DESCRIPTION

[0031] In order to make the purpose, advantages and features of the utility model clearer, the utility model 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 utility model. 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.

[0032] 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 utility model, "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.

[0033] [Example 1]

[0034] like Figure 1As shown, in order to cooperate with the three-dimensional curved sheath to pass through the inferior vena cava, through the tricuspid valve and enter the right ventricle 3 to ablate the ventricular septum 4, the ablation catheter 2 needs to go through two bends, namely the large bend when entering the right atrium from the inferior vena cava and the small bend at the head of the three-dimensional curved sheath.

[0035] In view of this, this embodiment provides a flexible ablation catheter, such as Figure 2 As shown, the flexible ablation catheter comprises: a catheter body 10 and a flexible portion 20, as shown in FIG. Figure 3 As shown, the flexible portion 20 includes a flexible single-lumen tube 201 and an electrode assembly, and the electrode assembly is connected to the distal end of the catheter body 10 through the flexible single-lumen tube 201 .

[0036] On this basis, this embodiment further provides an ablation system, which includes a three-dimensional curved sheath and the flexible ablation catheter provided in this embodiment, wherein the three-dimensional curved sheath is used to guide the flexible ablation catheter into place. The shape of the flexible ablation catheter can change in accordance with the shape of the three-dimensional curved sheath.

[0037] The flexible needle-carrying ablation catheter provided in this embodiment eliminates the relatively rigid bendable braided multi-lumen tube structure of conventional catheters and uses a flexible structure instead. During surgery, the catheter can be ablated vertically against the ventricular septum in the right ventricle in coordination with the curved shape of the three-dimensional curved sheath.

[0038] For ablation catheters, the reason why the distal bendable section of conventional catheters uses a multi-lumen tube is to guide the wires of different electrodes to pass through different cavities to avoid mutual interference between electrode signals. The flexible ablation catheter provided in this embodiment cancels the design of the multi-lumen tube structure, and provides a flexible protective tube for the wire to pass through. Specifically, the flexible part 20 also includes a wire protective tube 205, which is used for the wire of the electrode assembly to pass through. The wire protective tube 205 is passed through the flexible single-lumen tube 201 and extends to be fixed in the catheter body 10. At least the part of the wire protective tube 205 that passes through the flexible single-lumen tube 201 is a flexible tube. The flexible protective tube is fixed in the flexible single-lumen tube 201 by physical friction, and the proximal end extends to the catheter body 10 and is fixed by bonding with medical adhesive.

[0039] In addition, in the present embodiment, the flexible portion 20 may further include a saline tube 206, which is passed through the flexible single-lumen tube 201 and extends to pass through the proximal end of the catheter body 10. Both ends of the saline tube 206 may be bonded and fixed using a medical adhesive. At least the portion of the saline tube 206 that passes through the flexible single-lumen tube 201 is a flexible tube, that is, in the present embodiment, the provision of the saline tube 206 will not increase the hardness of the flexible portion 20.

[0040] Specifically, the electrode assembly may include a needle electrode 202, a head electrode 203 and a ring electrode 204, wherein the head electrode 203 is connected to the distal end of the flexible single-lumen tube 201, the needle electrode 202 can be movably inserted into the saline tube 206 and the distal end of the needle electrode 202 can extend out of the head electrode 203, and the ring electrode 204 is sleeved on the flexible single-lumen tube 201. The wire of the ring electrode and the wire of the head electrode are inserted into different wire protective tubes 205. The wires of the head electrode 203 and the ring electrode 204 are isolated and protected by flexible protective tubes respectively, which will not increase the hardness of the flexible part 20. It should be noted here that in some other embodiments, the electrode assembly may also adopt other electrode combinations, for example, the electrode assembly only includes the needle electrode 202 and the head electrode 203, or the number of the ring electrodes 204 is 2 or more, and so on. In addition, a magnetic positioning sensor, a temperature sensor, etc. may also be provided on the head electrode 203 , and the wire portion of such sensors may also be protected by the wire protection tube 205 .

[0041] Preferably, the distal end of the catheter body 10 has a first reduced diameter section (not shown) for the proximal end of the flexible single-lumen tube 201 to be sleeved, and the proximal end of the head electrode 203 has a second reduced diameter section (not shown) for the distal end of the flexible single-lumen tube 201 to be sleeved, that is, the distal end of the catheter body 10 and the proximal end of the head electrode 203 are provided with steps for the two ends of the flexible single-lumen tube 201 to be sleeved respectively. The design of the steps can, on the one hand, provide circumferential support for the flexible single-lumen tube 201, and on the other hand, facilitate the connection between the flexible single-lumen tube 201 and the head electrode 203 and the catheter body 10. After the two ends of the flexible single-lumen tube 201 are respectively sleeved on the step portions of the head electrode 203 and the catheter body 10, they can be further bonded and fixed using medical adhesives, thereby improving the connection strength.

[0042] In this embodiment, the materials of the flexible single-lumen tube 201, the wire protective tube 205 and the saline tube 206 can be selected from polyurethane (PU), thermoplastic polyurethane elastomer (TPU), polyvinyl chloride (PVC), nylon elastomer (Pebax), silicone, styrene thermoplastic elastomer (TPS), polyolefin thermoplastic elastomer (TPO), rubber-plastic blend elastomer (TPV), polyester rubber (TPEE) and other medical tubing made of soft polymer or thermoplastic elastomer materials that meet the standards for contact with the human body.

[0043] In addition, similar to conventional catheters, the flexible ablation catheter provided in this embodiment may also include a handle 30. The setting of the handle 30 is convenient for operation on the one hand, and is used for electrical connection between the wires of the electrode assembly and external devices on the other hand. The handle 30 can adopt a specific structure and functional design well known in the art, which will not be repeated here.

[0044] [Example 2]

[0045] The flexible ablation catheter provided in the first embodiment solves the problem of the high hardness of ordinary catheters in the three-dimensional curved sheath affecting the bending shape, but brings about the problem of insufficient support force of the needle electrode 202 in the catheter, thereby affecting the insertion of the needle electrode 202 into the myocardium.

[0046] In view of this, if Figure 4 As shown, compared with the first embodiment, the flexible ablation catheter provided in this embodiment has the flexible portion 20 further comprising a spring structure 207, the spring structure 207 is restricted from axial expansion and contraction and is allowed to bend, the spring structure 207 is arranged in the flexible single-lumen tube 201 along the axial direction of the flexible single-lumen tube 201, and the spring structure 207 is sleeved on the wire sheath 205 and the saline tube 206. That is, the flexible ablation catheter provided in this embodiment adds an axially incompressible spring structure 207 to the flexible single-lumen tube 201 to provide a supporting force, so as to ensure that the needle electrode 202 is smoothly inserted into the myocardium.

[0047] The proximal end of the spring structure 207 can also be sleeved on the first reduced diameter section and fixed by bonding, so it can be understood that the spring structure 207 and the flexible single-lumen tube 201 are sequentially stacked and sleeved on the distal step of the catheter body 10 from the inside to the outside, and are further bonded and fixed. The distal step of the catheter body 10 also plays a role of circumferential support for the spring structure 207.

[0048] Specifically, the spring structure 207 is a dense spring, which can be understood as a spring with no spacing between coils. After the positions of both ends are limited, it cannot be stretched or compressed. The dense spring is located in the flexible single-lumen tube 201, and its outer diameter is smaller than the inner diameter of the flexible single-lumen tube 201. The wire protection tube 205 and the saline tube 206 both pass through the inner cavity of the dense spring. The wire protection tube 205 also protects the wire from failure or breakage of the insulation layer due to friction with the dense spring during the use of the catheter.

[0049] Preferably, the length of the spring structure 207 is 1 / 2 to 9 / 10 of the total length of the flexible portion 20. For example, the total length of the flexible portion 20 is 80 cm to 150 cm, the length of the spring structure 207 is 40 cm to 135 cm, and the wire diameter of the spring structure 207 is 0.1 mm to 0.5 mm. It is understandable that the wire diameter mentioned here refers to the diameter of the metal wire used to form the spring structure 207. The parameters of the spring structure 207 are designed to provide a certain support force for the flexible portion 20, while its hardness can change with the bending shape of the three-dimensional bending sheath. The spring structure 207 can be made of carbon spring steel or alloy spring steel: typical grades are 50Crv, 55CrSi, 60Si 2 Mn, stainless steel for springs, elastic alloys, nickel and nickel alloys, etc.

[0050] [Example 3]

[0051] In addition, due to the matching problem between the inner and outer diameters of the flexible single-lumen tube 201 and the size of the head electrode 203, as well as the installation of the ring electrode 204 and the fixing process of the dense spring, it is difficult to directly bond the flexible single-lumen tube 201 to the head electrode 203. Figure 5 As shown, the flexible ablation catheter provided in this embodiment is relative to the second embodiment, the flexible portion 20 further includes a hard tube segment 208, and the electrode assembly is connected to the distal end of the flexible single-lumen tube 201 through the hard tube segment 208, thereby reducing the difficulty in the manufacturing process. The total length of the flexible portion 20 is 80 cm to 150 cm, and the length of the hard tube segment 208 is 4 mm to 7 mm.

[0052] The hard tube segment 208 is shorter than the flexible portion 20 . The setting of the hard tube segment 208 of this length will not affect the change of the bending shape of the flexible portion 20 following the three-dimensional bending sheath, but will provide the flexible portion 20 with a certain supporting force.

[0053] In addition, preferably, the inner cavity of the hard tube section 208 is filled by glue injection. On the one hand, the glue injection can improve the supporting force. On the other hand, the distal end of the spring structure 207 can be fixed by the filled colloid, thereby improving the convenience of fixing the distal end of the spring structure 207.

[0054] The material of the hard pipe section 208 can be selected from hard medical polymer pipes such as polyethylene (PE), polypropylene (PP), polyimide (PI), PEEK, polyvinyl chloride (PVC), polyoxymethylene (POM), polymethyl methacrylate (PMMA), perfluoroethylene propylene copolymer (FEP), and polystyrene (PS).

[0055] To summarize, compared with the prior art, the flexible ablation catheter and ablation system provided by the utility model have reduced hardness of the distal part of the catheter, and are better used with the three-dimensional curved sheath, thereby achieving ablation of hypertrophic ventricular septum in the right ventricle; the bendable but incompressible nature of the spring structure provides better support for the needle electrode when it penetrates the myocardium, solving the problem of the inability to penetrate the myocardium due to insufficient support force due to the distal part of the catheter being too soft.

[0056] It should be noted that although the flexible ablation catheter provided by the utility model is intended to solve the problem of ablation of the ventricular septum, ablation of the ventricular septum should not constitute a limitation on the flexible ablation catheter provided by the utility model. The flexible ablation catheter provided by the utility model can also be applied to other ablation and / or puncture scenarios.

[0057] It should also 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 embodiments can be referenced to each other. In addition, the different parts between the embodiments can also be used in combination with each other, and the present utility model is not limited to this.

[0058] 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 above disclosed technical content 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 based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A flexible ablation catheter, characterized in that: include: a catheter body and a flexible portion; The flexible part includes a flexible single-lumen tube and an electrode assembly, and the electrode assembly is connected to the distal end of the catheter body through the flexible single-lumen tube; the flexible part also includes a spring structure, and the spring structure is restricted from axial expansion and contraction and allowed to bend. The spring structure is arranged in the flexible single-lumen tube and extends along the axial direction of the flexible single-lumen tube, and the outer diameter of the spring structure matches the inner diameter of the flexible single-lumen tube.

2. The flexible ablation catheter according to claim 1, characterized in that: The distal end of the catheter body has a first reduced diameter section, the proximal end of the spring structure is sleeved on the first reduced diameter section and fixed by bonding, and the distal end of the spring structure is fixed in the flexible single-lumen tube by bonding or glue injection.

3. The flexible ablation catheter according to claim 2, characterized in that: The length of the spring structure is 1 / 2 to 9 / 10 of the total length of the flexible part, and the wire diameter of the spring structure is 0.1 mm to 0.5 mm.

4. The flexible ablation catheter according to claim 1, characterized in that: The flexible part also includes a hard tube segment, and the electrode assembly is connected to the distal end of the flexible single-lumen tube through the hard tube segment. The total length of the flexible part is 80 cm to 150 cm, and the length of the hard tube segment is 4 mm to 7 mm.

5. The flexible ablation catheter according to claim 4, characterized in that: The inner cavity of the hard pipe section is filled by glue injection.

6. The flexible ablation catheter according to claim 4, characterized in that: The flexible single-lumen tube is made of a medical tube made of a soft polymer or a thermoplastic elastomer, and the hard tube section is made of a medical tube made of a hard polymer.

7. The flexible ablation catheter according to claim 1, characterized in that: The flexible part also includes a wire protection tube and a saline tube, wherein the wire protection tube is used for passing the wire of the electrode assembly; wherein the saline tube is passed through the flexible single-lumen tube and extends to pass out of the proximal end of the catheter body, the wire protection tube is passed through the flexible single-lumen tube and extends to be fixed in the catheter body, and at least the parts of the saline tube and the wire protection tube passing through the flexible single-lumen tube are flexible tubes.

8. The flexible ablation catheter according to claim 7, characterized in that: The electrode assembly includes a needle electrode, a head electrode and a ring electrode. The head electrode is connected to the distal end of the flexible single-lumen tube. The needle electrode can be movably inserted into the saline tube and the distal end of the needle electrode can extend out of the head electrode. The ring electrode is sleeved on the flexible single-lumen tube. The wire of the ring electrode and the wire of the head electrode are inserted into different wire protective tubes.

9. The flexible ablation catheter according to claim 8, characterized in that: The proximal end of the head electrode has a second reduced diameter section, and the proximal end of the flexible single-lumen tube is sleeved on the second reduced diameter section and fixed by bonding.

10. An ablation system, characterized in that: include: A three-dimensional curved sheath and a flexible ablation catheter as described in any one of claims 1 to 9, wherein the three-dimensional curved sheath is used to guide the flexible ablation catheter into place, and the shape of the flexible ablation catheter can change in accordance with the shape of the three-dimensional curved sheath.

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