CN217138237U - Ablation device - Google Patents

Abstract

The utility model provides an ablation device, including the portion of melting of pipe and connecting the pipe distal end, should melt the portion and include expandable bearing structure and locate the electrode on the bearing structure, when bearing structure is in the natural state of expansion, bearing structure is the extension of plane heliciform, and has the overlap region. When the pressure of the airway wall with slightly smaller inner diameter is applied, the ablation device can well adapt to the shape of the target tissue to generate regular deformation, so that the ablation device can be well attached to the target tissue.

Description

Ablation device

Technical Field

The utility model belongs to the technical field of medical instrument, concretely relates to melt device.

Background

Chronic Obstructive Pulmonary Disease (COPD) is currently the most common type of Chronic airway Disease, can severely affect the quality of life of patients, and is an important cause of death. It is mainly characterized by persistent airflow limitation and corresponding respiratory symptoms, the main pathological manifestations being airway and/or alveolar abnormalities. As the condition progresses, dyspnea is noticed when non-intense activities such as walking are performed. Over time, symptoms of COPD may appear with smaller and smaller amounts of activity until all the time they appear, severely limiting a person's ability to complete normal activities. Pulmonary diseases are often characterized by obstruction of the airway cavity, thickening of the airway wall, changes in structures within or around the airway wall, or combinations thereof. Airway obstruction can significantly reduce the amount of gas exchange in the lungs and thus cause breathing difficulties. Obstruction of the airway lumen may be caused by excess intraluminal mucus or edematous liquid or both. Airway wall thickening may be caused by excessive contraction of airway smooth muscle, airway smooth muscle hypertrophy, mucus gland hyperplasia, inflammation, edema, or a combination thereof. Structural changes around the airway, such as destruction of the lung tissue itself, may result in loss of radial contraction of the airway wall and subsequent airway narrowing. Asthma and COPD are serious diseases, with an increasing number of patients.

As a new trend in recent years, TLD (Targeted Lung Denervation) is a new trend for treating COPD, and TLD ablation mainly involves ablation of parasympathetic nerves in the bronchial adventitia by an ablation device to block the transmission of nerve signals, so that airway smooth muscle is relaxed and mucus secretion is reduced, thereby improving the symptoms of airway obstruction and dyspnea. The existing ablation device generally comprises a catheter and an electrode arranged at the far end of the catheter, ablation energy is generated through the electrode to block parasympathetic nerves, so that the far end of the catheter is required to be well attached to the wall of an airway, the ablation energy of the electrode is ensured to be applied to target tissues,

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an ablation device, this ablation device can adapt to target tissue form, realizes good laminating with target tissue.

The purpose is realized by the following steps:

a first aspect of the present invention provides an ablation device, comprising: a catheter and an ablation part connected with the distal end of the catheter; the ablation part comprises an expandable support structure and an electrode arranged on the support structure, and when the support structure is in a natural unfolding state, the support structure extends in a plane spiral shape and is provided with an overlapping area.

In one embodiment, the support structure comprises an outer annular ring portion and an inner ring portion connected to the outer ring portion when in a naturally deployed state, the inner ring portion being located within the outer ring portion and an overlap region being formed between an inner surface of the outer ring portion and an outer surface of the inner ring portion.

In one embodiment, the inner surface of the outer ring portion is provided with a guide groove in the overlapping region, and the outer surface of the inner ring portion is slidable along the guide groove.

In one embodiment, the outer surface of the inner ring portion in the overlapping region is provided with at least one protrusion that fits into the guide groove.

In one embodiment, the support structure comprises a flexible region and a reinforcing region connected with the flexible region along the length direction, and the rigidity of the flexible region is smaller than that of the reinforcing region.

In one embodiment, the flexible region is provided with a helical cut along its length.

In one embodiment, the supporting structure comprises an end section which can freely move along the length direction and a main body section which is connected with the end section, and the surface of the end section is provided with a flexible covering so that the surface hardness of the end section is smaller than that of the main body section.

In one embodiment, the outer loop portion has a first end close to the catheter and a second end far away from the catheter along the length direction, the ablation device comprises a plurality of electrodes arranged on the surface of the outer loop portion, the plurality of electrodes comprises a head electrode, a tail electrode and an intermediate electrode positioned between the head electrode and the tail electrode, the head electrode is the electrode closest to the first end of the outer loop portion along the length direction of the outer loop portion, the tail electrode is the electrode farthest from the first end of the outer loop portion, and the sum of the distance from the head electrode to the first end of the outer loop portion and the distance from the tail electrode to the second end of the outer loop portion is larger than the distance from the head electrode to the intermediate electrode adjacent to the head electrode and the distance from the tail electrode to the intermediate electrode adjacent to the head electrode.

In one embodiment, the guide tube includes a first channel, the support structure includes a first cooling hole and a second channel communicated with the first channel, the first cooling hole is disposed on the surface of the support structure and communicates the second channel with the outside, and the first channel and the second channel are used for conveying cooling media.

In one embodiment, the ablation device further comprises a cooling balloon comprising a balloon body having an expandable inner lumen, the balloon body being disposable within the support structure, a delivery channel in communication with the expandable inner lumen for delivering a cooling medium into the expandable inner lumen to inflate the expandable inner lumen.

In one embodiment, the surface of the cooling balloon is provided with a plurality of second cooling holes, the second cooling holes are used for communicating the expandable inner cavity with the outside, and the second cooling holes are used for conveying and discharging the cooling medium in the expandable inner cavity.

In one embodiment, the ablation device further comprises a cooling balloon comprising a balloon body having an expandable inner lumen, a delivery channel in communication with the expandable inner lumen, the balloon body being insertable within the support structure, the delivery channel for delivering a cooling medium into the expandable inner lumen, and a recovery channel for recovering the cooling medium from the expandable inner lumen.

The utility model provides an ablation device, including bearing structure and locate the electrode on the bearing structure, this bearing structure is the extension of plane heliciform, and has overlap region, when the in-process that implements to melt receives the pressure of the gas channel wall that the internal diameter is slightly littleer, and bearing structure can be under overlap region's guide, whole inside shrink, makes the form of the adaptation target tissue that this ablation device can be fine and takes place the deformation of law to realize good laminating with the target tissue.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like parts are designated by like reference numerals throughout the drawings. Wherein:

fig. 1 is a schematic structural view of an ablation device according to an embodiment of the present invention;

FIG. 2 is a schematic view of the ablation portion and catheter of FIG. 1;

FIG. 3 is a schematic view of the ablation portion of FIG. 2;

fig. 4 is a schematic cross-sectional view of a guide groove according to an embodiment of the present invention;

fig. 5 is a schematic cross-sectional view of a guide groove and a projection according to an embodiment of the present invention;

fig. 6 is a schematic structural view of a support structure according to another embodiment of the present invention;

FIG. 7 is a cross-sectional schematic view of an end section of the support structure of FIG. 6;

FIG. 8 is a partial schematic view of a flexible region and a reinforced region of a support structure according to another embodiment of the present invention;

FIG. 9 is a schematic view of a support structure and a conduit according to yet another embodiment of the present invention;

fig. 10 is a schematic structural view of a cooling balloon according to an embodiment of the present invention;

fig. 11 is a schematic structural view of a cooling balloon according to another embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For convenience of description, spatially relative terms, such as "inner", "outer", "lower", "below", "upper", "above", and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

To more clearly describe the structure of the ablation device, the terms "proximal" and "distal" are defined herein as terms commonly used in the interventional medical field. Specifically, "distal" refers to the end of the surgical procedure that is distal from the operator, and "proximal" refers to the end of the surgical procedure that is proximal to the operator.

Example 1

Referring to fig. 1, the present embodiment provides an ablation device 100 for delivering ablation energy to a target tissue to substantially change the electrical shape, mechanical properties, chemical properties, or other properties of the target tissue. For convenience of understanding, the present embodiment is described with the application scenario of the pulmonary nerve ablation, but the application scenario of the ablation apparatus 100 of the present invention is not limited thereto, and may also be applied in various environments, such as ablation of tissues such as renal artery, pulmonary vein, left atrial appendage, and ventricle.

The ablation device 100 of the present embodiment includes a catheter 10, an ablation portion 20, and an operation handle 30. Wherein the catheter 10 may be a vertical tubular structure, the proximal end of the catheter 10 is connected to an operation handle 30, the distal end of the catheter 10 is connected to the ablation portion 20, and the operation handle 30 is provided with an electrical connector (not shown) for connecting to an energy generator for generating ablation energy including, but not limited to, heat energy, cold energy, electrical energy, acoustic energy, radio frequency energy, pulsed high voltage energy, mechanical energy, ionizing radiation, optical energy, and combinations thereof, and other types of energy suitable for treating tissue. In this embodiment, the energy generator is a radio frequency generator that outputs radio frequency energy at a desired frequency, and in other embodiments, any other suitable energy generator type may be selected.

Referring to fig. 2 and 3, the ablation portion 20 includes an expandable support structure 21, and an electrode 22 disposed on the support structure 21. The support structure 21 has radially expandable properties, and when in a naturally deployed state (i.e., a naturally expanded state in the absence of an external human force), the support structure 21 extends in a planar spiral configuration and has an overlap region 213. The support structure 21 is radially compressible or unbendable under an external force, and self-expands and returns to a naturally expanded state when the external force is removed. When the ablation operation is performed, the catheter 10 and the ablation part 20 can be accommodated in the sheath, the catheter 10 and the ablation part 20 are conveyed into the airway through the sheath, the sheath is withdrawn to release the ablation part 20, the ablation part 20 is expanded and unfolded in the airway, the ablation part 20 is controlled by the energy generator to output ablation energy to ablate parasympathetic nerves in the outer bronchial membrane, so that the transmission of nerve signals is blocked, after the ablation is completed, the ablation energy is stopped by controlling the energy generator, the catheter 10 and the ablation part 20 are withdrawn into the sheath, and then the catheter 10 and the ablation part 20 are withdrawn out of the sheath together with the sheath.

To ensure that the support structure 21 can maintain its natural deployed configuration after the external force is removed, the support structure 21 can be made by heat setting an elongated rod-shaped member or an elongated tubular member made of elastic metal material, wherein the elastic metal material includes known materials or various combinations of biocompatible materials, such as cobalt, chromium, nickel, titanium, magnesium, iron, alloys of two or more single metals, 316L stainless steel, nitinol, etc., or other elastic metal materials with biocompatibility, and is implanted into the medical device. In addition, in order to make the edge of the ablation part 20 better fit with the target tissue, the included angle between the catheter 10 and the plane of the ablation part 20 is set to be 85-95 degrees.

Illustratively, the support structure 21 of the present embodiment is made of nitinol rod material, and includes an outer ring portion 211 and an inner ring portion 212 located inside the outer ring portion 211 when in a naturally deployed state. Wherein the outer race portion 211 is generally annular having a first end 214 and a second end 215, and the inner race portion 212 is generally arcuate having a fixed end and a free end. The first end 214 of the outer collar portion 211 is fixedly attached to the distal end of the catheter 10, the second end 215 of the outer collar portion 211 is fixedly attached to the fixed end of the inner collar portion 212, and the free end of the inner collar portion 212 is movable relative to the outer collar portion 211.

An overlap region 213, i.e., a region in which there is mutual contact between the inner surface of the outer ring portion 211 and the outer surface of the inner ring portion 212, is formed between the inner surface of the outer ring portion 211 and the outer surface of the inner ring portion 212. In this embodiment, the overlapping area 213 is a single continuous overlapping area 213. When the support structure 21 is subjected to a radially acting force, the inner ring portion 212 extends forward following the shape of the inner surface of the outer ring portion 211 under the guidance of the overlap region 213, so that the support structure 21 as a whole is retracted to reduce the radial dimension. In addition, because the inner ring portion 212 is always attached to the outer ring portion 211 for stable deformation, the uncontrollable axial deformation of the supporting structure 21 under the action of the radial force can be prevented, so that the electrode 22 on the supporting structure 21 cannot be attached to the target tissue well, and ablation failure can be prevented. Referring to fig. 4, in order to provide a better effect of guiding deformation to the overlapped region 213, a guide groove 23 may be provided on an inner surface of the outer ring portion 211 so that an outer surface of the inner ring portion 212 may slide along the guide groove 23. Further, referring to fig. 5, the outer surface of the inner ring portion 212 may be further provided with at least one protrusion 24 engaged with the guide groove 23. It is understood that in other embodiments, a plurality of overlapping regions 213 may be formed between the inner surface of the outer ring portion 211 and the outer surface of the inner ring portion 212. In addition, the size of the overlapping region 213 affects the performance of the support structure 21, when the length of the overlapping region 213 is too long, the overlapping region 213 may greatly limit the deformation of the support structure 21, so that the support structure 21 cannot adapt to the form of the target tissue flexibly and quickly, and when the length of the overlapping region 213 is too short, the guiding function of the overlapping region 213 is too small, and there may be a risk of axial slippage between the outer ring portion 211 and the inner ring portion 212. In this embodiment, in the naturally unfolded state, a ratio of the total length of the overlapping region 213 to the total length of the supporting structure 21 is in a range of 0.1 to 0.4, and in other embodiments, a ratio of the total length of the overlapping region 213 to the total length of the supporting structure 21 is in a range of 1:9 to 3:11, wherein the total length of the overlapping region 213 is a sum of lengths of all the overlapping regions 213 on the supporting structure 21. In other embodiments, the ratio of the total length of the overlapping area 213 to the total length of the supporting structure 21 is not limited to the above-mentioned exemplary value range, and the size of the overlapping area 213 can be selected according to the specific application.

To ensure that the ablation device 100 of this embodiment forms a uniform, continuous annular ablation zone at a depth in the target tissue to maximally block the transmission of nerve signals, a plurality of electrodes 22 are distributed on the support structure 21, and the electrodes 22 may include, but are not limited to, one or more of a monopolar electrode, a bipolar electrode, a metal electrode, a wire electrode, a needle electrode, and any other suitable electrode type, and may form an array of annular lesions each extending along only a portion of the circumferential direction of the inner wall of the target tissue. In this embodiment, 6 electrodes 22 are fixedly connected to the outer ring portion 211 at regular intervals along the length direction, the electrodes 22 are substantially tubular and are sleeved on the outer surface of the outer ring portion 211, and the electrodes 22 are not disposed on the inner ring portion 212.

In the longitudinal direction of the outer ring portion 211, the electrode 22 closest to the first end 214 of the outer ring portion 211 is a leading electrode 22a, the electrode 22 farthest from the first end 214 of the outer ring portion 211 is a trailing electrode 22c, and the electrode 22 located between the leading electrode 22a and the trailing electrode 22c is an intermediate electrode 22 b.

The distance between the leading electrode 22a and the trailing electrode 22c is along the length direction of the outer ring portion 211, the distance from the leading electrode 22a to the first end 214 of the outer ring portion 211 is L1, the distance from the trailing electrode 22c to the second end 215 of the outer ring portion 211 is L2, and the sum of L1 and L2 is L3. L3 should be suitable, when the L3 is too large, there is an unerased region between the damaged region generated by the leading electrode 22a and the damaged region generated by the trailing electrode 22c, so that transmission of nerve signals cannot be completely blocked; when L3 is too small, the support structure 21 is deformed by the radial pressure of the target region to reduce the distance between the leading electrode 22a and the trailing electrode 22c, so that there is a large overlap between the damaged region generated by the leading electrode 22a and the damaged region generated by the trailing electrode 22c, and thus, the target tissue is damaged excessively. The distance between the leading electrode 22a and the trailing electrode 22c is reduced to prevent the support structure 21 from deforming under the radial pressure of the target region, so that there is a large overlap between the damaged region generated by the leading electrode 22a and the damaged region generated by the trailing electrode 22c, and thus excessive damage is caused to the target tissue. L3 should be greater than or equal to the distance L4 between the leading electrode 22a and the intermediate electrode 22b adjacent thereto, and L3 should be greater than or equal to the distance L5 between the leading electrode 22a and the intermediate electrode 22b adjacent thereto. For example, L4 and L5 are substantially equal, and the ratio between L3 and L4 or L5 is in the range of 1-1.3. In addition, taking the ablation part 20 with 6 electrodes 22 as an example, the ratio between the L3 and the total length of the outer ring part 211 ranges from 0.15 to 0.4. The ratio between the L3 and the total length of the outer ring portion 211 of this embodiment is suitable, which not only ensures the formation of a complete annular damage region, but also reduces the risk of excessive damage to the target region. It will be appreciated that in other embodiments, the number, type, shape, material, and spacing between adjacent electrodes 22 may be adjusted according to the particular application.

In this embodiment, an insulating layer, such as Pebax or other high molecular material, may be further disposed between the electrode 22 and the supporting structure 21. The conductive nature of the support structure 21 is effectively prevented from interfering with the rf and feedback circuitry by the provision of the insulating layer.

Sensors may also be provided within the electrode 22 to control the energy output and ablation effect of the ablation process. The sensor may be placed where the electrode 22 engages the airway wall to provide as accurate feedback as possible of the energy changes in the ablation zone. According to actual needs, the sensor can acquire parameters such as temperature, pressure and impedance. In other embodiments, the sensor may be omitted.

The ablation device 100 may also include a wire having an insulation layer disposed on a surface of the wire. The electrodes 22 may be connected to wires by soldering, etc., and the sensor may be connected to corresponding wires. For a support structure 21 having an internal channel, the electrodes 22 and the leads of the sensor may be introduced into the internal channel of the support structure 21 through corresponding through holes in the support structure 21. The wires of the plurality of electrodes 22 and the wires of the sensor can all be gathered inside the support structure 21, then pass through the internal lumen of the catheter 10 to reach the operating handle 30, and are connected to the circuit connector. Wherein the internal lumen of the support structure 21 and the internal lumen of the catheter 10 act to constrain and protect the guide wire. In other embodiments, no internal channels may be provided in the support structure 21 or the catheter 10, and the wires could likewise extend along the outer surface of the support structure 21 and catheter 10 and communicate with the circuit connectors in the operating handle 30.

Example 2

Referring to fig. 6 and 7, the ablation device 100 of the present embodiment is substantially the same as the ablation device 100 of embodiment 1, except that a flexible covering 216a is further provided on the support structure 21 of the present embodiment.

Illustratively, the supporting structure 21 of the present embodiment includes an end section 216 freely movable along the length direction and a main body section 217 connected to the end section 216, the end section 216 is externally provided with a flexible covering 216a, which can be made of a material with a smaller hardness, such as silicone rubber, TPU, PEBAX, etc., so that the surface hardness of the end section 216 is smaller than that of the main body section 217.

The supporting structure 21 is placed in the sheath during the conveying process, the sheath is constrained to be in a straightened state, when the sheath is retracted to remove the constraint on the supporting structure 21, the supporting structure 21 is radially expanded, and the end section 216 of the supporting structure 21 has an inward rolling process due to the approximately planar spiral shape, so that the end section 216 is easy to contact with the target tissue in the process.

Further, a flexible region 218 may also be provided on the support structure 21. Wherein the flexible region 218 of the support structure 21 is provided with a helical slot 2181 along the length direction, the helical slot 2181 is obtained by laser cutting or the like, and for the support structure 21 with an internal cavity, the helical slot 2181 may penetrate through the wall of the support structure 21, or may penetrate through a part of the wall of the support structure 21, or may not penetrate through the wall of the support structure 21. The helical slot 2181 may be a single helical slot, a double helical slot, or a multiple helical slot. For example, the helical slot 2181 of the present embodiment is a single helical slot. The pitch, number and cutting width of helical slots 2181 are adjusted, and in other embodiments, other types of slot shapes may be used.

Referring to fig. 8, in other embodiments, a plurality of flexible regions 218 and a reinforcing region 219 connected to the flexible regions 218 are provided on the support structure 21. Wherein the helical slot 2181 of the flexible region 218 is a double helical slot comprising a first helical slot 218a and a second helical slot 218b, the first helical slot 218a and the second helical slot 218b being substantially parallel in a length direction. Adjacent flexible regions 218 are spaced apart by reinforced regions 219, the reinforced regions 219 being not provided with undercuts, and the stiffness of the reinforced regions 219 being greater than the stiffness of the flexible regions 218. This provides the benefit of the flexible region 218 to improve the flexibility and elasticity of the support structure 21, and the reinforced region 219 to provide better support for the support structure 21, so that the support structure 21 of this embodiment has excellent expansion performance and can maintain a stable form in the deployed state, further improving the adherence of the support structure 21.

Example 3

This embodiment is based on embodiments 1-2, and can be used to cool the target area of epithelial tissue during ablation in order to reduce the possibility of irreversible damage to the target tissue (e.g., airway epithelial tissue) after heating during ablation.

Referring to fig. 9, the operating handle 30 of the present embodiment further includes a connector (not shown) for connecting a cooling device (not shown), the interior of the conduit 10 further includes a first channel communicated with the cooling device, the interior of the supporting structure 21 further includes a second channel communicated with the first channel, the supporting structure 21 is provided with at least one first cooling hole 25, and the first cooling hole 25 is disposed on the surface of the supporting structure 21. The cooling device may deliver a cooling medium (e.g., saline, etc.) to the first channel and to the second channel, where the cooling medium may be discharged through the first cooling holes 25 and out to the target tissue (e.g., directly into contact with the epithelial tissue of the airway) to remove some of the heat. The cooling medium discharged into the target tissue may be recovered using a bronchoscope after the treatment is completed.

In this embodiment, the catheter 10 may further include a third lumen therein, and the support structure 21 may further include a fourth lumen therein for receiving a guide wire within the ablation device 100 to protect the guide wire.

Example 4

This example proposes another cooling treatment method based on example 3.

Referring to fig. 10, the ablation device 100 of the present embodiment further includes a cooling balloon 40. The cooling balloon 40 includes a balloon body 41 having an inflatable inner lumen, a first elongated tubular structure 42 connected to the balloon body 41, and second cooling holes 43 disposed on a surface of the cooling balloon 40. Wherein the proximal end of the first elongated tubular structure 42 is connected to the cooling device by the operating handle 30, the distal end of the first elongated tubular structure 42 is connected to the balloon body 41, and the lumen of the first elongated tubular structure 42 forms a delivery channel in communication with the inflatable lumen of the balloon body 41 for delivering the cooling medium within the cooling device into the inflatable lumen. The inflatable lumen is inflated when inflated with a cooling medium while balloon body 41 is in an inflated state, and deflated when the cooling medium is removed from the inflatable lumen while balloon body 41 is in a deflated state.

In this embodiment, the balloon surface is provided with a circle of second cooling holes 43, and the circle of second cooling holes 43 comprises a plurality of second cooling holes 43 arranged at intervals along the circumferential direction. In other embodiments, the balloon surface may be provided with a plurality of circles of second cooling holes 43, or the arrangement of the second cooling holes 43 may be completely different from that of the present embodiment.

In the ablation process, the cooling balloon 40 in the contracted state is firstly inserted into the support structure 21, the cooling device conveys the cooling medium into the expandable inner cavity of the balloon body 41 through the conveying channel to enable the balloon body 41 to be in the expanded state, the outer surface of the expanded balloon body 41 is tightly attached to the inner wall of the target tissue, and the cooling medium is discharged to the inner wall of the target tissue through the second cooling holes 43. It should be noted that, since the electrode 22 outputs ablation energy to heat the surrounding tissue, the second cooling holes 43 should be located as close as possible to the electrode 22 (see fig. 3), for example, the second cooling holes 43 are all located near the distal end surface of the support structure 21, so that the cooling medium can be discharged to the heated tissue as much as possible to improve the cooling effect.

In the embodiment, the cooling balloon 40 is used for cooling the target tissue, so that the possibility of irreversible damage to the target tissue after heating is effectively reduced. In addition, the cooling balloon 40 can also drive the support structure 21 to adhere better to the wall in the inflated state.

Example 5

This embodiment proposes another cooling balloon 40 on the basis of embodiment 4.

Referring to fig. 11, the cooling balloon 40 of the present embodiment includes a balloon body 41 having an inflatable inner lumen, a second elongated tubular structure 44 and a third elongated tubular structure 45 connected to the balloon body 41. Wherein the proximal end of the second elongated tubular structure 44 is externally connected to the cooling device via the operating handle 30, and the distal end of the second elongated tubular structure 44 is fixedly connected to the proximal end of the balloon body 41. The third elongated tubular structure 45 is disposed through the lumen of the second elongated tubular structure 44, and the outer diameter of the third elongated tubular structure 45 is smaller than the inner diameter of the second elongated tubular structure 44, and a delivery channel is formed between the outer surface of the third elongated tubular structure 45 and the inner surface of the second elongated tubular structure 44, the delivery channel being in communication with the inflatable inner lumen of the balloon body 41 for delivering the cooling medium in the cooling device to the inflatable inner lumen. The proximal end of the third elongated tubular structure 45 is externally connected to the retrieval device by the manipulation handle 30, and the distal end of the third elongated tubular structure 45 is located within the balloon body 41 and is fixedly connected to the distal end of the balloon body 41. The third elongated tubular structure 45 is provided with a recovery hole 46 communicating the recovery channel with the expandable inner cavity for outputting the cooling medium in the expandable inner cavity to the recovery device through the recovery channel.

In the ablation process, the cooling balloon 40 in the contracted state is firstly inserted into the support structure 21, the cooling device conveys a cooling medium into the expandable inner cavity of the balloon body 41 through the conveying channel to enable the balloon body 41 to be in the expanded state, and the outer surface of the expanded balloon body 41 is tightly attached to the inner wall of the target tissue to cool the inner wall of the target tissue. The cooling medium in the expandable inner cavity is recovered through the recovery channel by applying negative pressure to the recovery channel, so that a cooling loop is formed. The construction of the cooling circuit facilitates the continuous cooling of the target tissue and prevents excessive cooling medium from entering the body.

Further, the distance from the recovery hole 46 to the distal end of the balloon body 41 is smaller than the distance from the recovery hole 46 to the proximal end of the balloon body 41. The arrangement can recover the cooling medium after the cooling medium is fully contacted with the tissue of the ablation area, and can cool the target tissue to the maximum extent.

In other embodiments, the third elongated tubular structure 45 may be located outside the second elongated tubular structure 44 and the balloon body 41, and may also form a cooling circuit with the second elongated tubular structure 44 and the balloon body 41. In addition, in other embodiments, the third elongate tubular structure 45 may be omitted, and the lumen of the second elongate tubular structure 44 may serve as a delivery channel for delivering the cooling medium into the expandable body and as a recovery channel for delivering the cooling medium from the expandable body to the recovery device, wherein the delivering and recovering of the cooling medium during the ablation process may be repeated as many times as required for cooling.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (12)

1. An ablation device, comprising: a catheter and an ablation part connected with the distal end of the catheter; the ablation part comprises an expandable support structure and an electrode arranged on the support structure, and when the support structure is in a natural unfolding state, the support structure extends in a plane spiral shape and is provided with an overlapping area.

2. The ablation device of claim 1, wherein the support structure comprises an outer annular portion and an inner annular portion connected to the outer annular portion when in a naturally deployed state, the inner annular portion being positioned within the outer annular portion and an overlap region being formed between an inner surface of the outer annular portion and an outer surface of the inner annular portion.

3. The ablation device of claim 2, wherein an inner surface of the outer loop portion is provided with a guide slot in the overlap region, and an outer surface of the inner loop portion is slidable along the guide slot.

4. The ablation device of claim 3, wherein an outer surface of the inner loop portion in the overlap region is provided with at least one protrusion that engages the guide slot.

5. The ablation device of claim 1, wherein the support structure includes a flexible region and a reinforced region connected to the flexible region along a length direction, the flexible region having a stiffness less than a stiffness of the reinforced region.

6. The ablation device of claim 5, wherein the flexible region is provided with a helical cut along a length thereof.

7. The ablation device of claim 1, wherein the support structure includes a freely movable end section and a body section connected to the end section along a length direction, the end section being provided with a flexible covering on a surface thereof such that the end section has a surface hardness less than a surface hardness of the body section.

8. The ablation device of claim 2, wherein the outer loop portion has a first end lengthwise proximate the catheter and a second end distal the catheter, the ablation device comprises a plurality of electrodes arranged on the surface of the outer ring part, a head electrode, a tail electrode and a middle electrode positioned between the head electrode and the tail electrode are arranged in the plurality of electrodes, the leading electrode is the electrode closest to the first end of the outer ring section in the length direction of the outer ring section, the end electrode is the electrode farthest from the first end of the outer ring part, and the sum of the distance from the head electrode to the first end of the outer ring part and the distance from the end electrode to the second end of the outer ring part is larger than the distance from the head electrode to the middle electrode adjacent to the head electrode and the distance from the end electrode to the middle electrode adjacent to the head electrode.

9. The ablation device of claim 1, wherein the catheter comprises a first channel, the support structure comprises a first cooling hole and a second channel communicated with the first channel, the first cooling hole is formed in the surface of the support structure and communicates the second channel with the outside, and the first channel and the second channel are used for conveying a cooling medium.

10. The ablation device of claim 1, further comprising a cooling balloon including a balloon body having an expandable inner lumen, the balloon body being disposable within the support structure, a delivery passage in communication with the expandable inner lumen for delivering a cooling medium into the expandable inner lumen to inflate the expandable inner lumen.

11. The ablation device of claim 10, wherein the cooling balloon surface is provided with a plurality of second cooling holes, the second cooling holes communicating the expandable inner cavity with the outside, the second cooling holes being used for delivering a cooling medium out of the expandable inner cavity.

12. The ablation device of claim 1, further comprising a cooling balloon including a balloon body having an expandable inner lumen, the balloon body being disposable within the support structure, a delivery channel in communication with the expandable inner lumen for delivering a cooling medium into the expandable inner lumen, and a recovery channel for recovering the cooling medium from the expandable inner lumen.

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