Cryoablation catheter

Abstract

The present invention relates to a cryoablation catheter, and relates to the field of ablation technology. The cryoablation catheter of the present invention includes an input tube for conveying a working medium and a cold tube assembly connected to the input tube, wherein the cold tube assembly includes a cold tube main tube and a cold tube branch tube. By adopting a method of dividing the cold tube branch tube into multiple cold tube branches, the temperature of the working medium can be quickly reduced to the required temperature when it is conveyed to the target area, so that the corresponding working medium can be stored and used at room temperature, avoiding equipment such as cold sources and cold tubes, which is conducive to the miniaturization and lightweight of the equipment; in addition, at the far end of the cold tube branch tube, components such as the input tube do not need to be provided with insulation / insulation components, because the working medium it conveys is a room temperature working medium, and the working medium can be kept at room temperature before being conveyed to the cold tube branch tube, so there is no need to take special insulation / insulation measures for components such as the input tube, so the cryoablation catheter can be further miniaturized and lightweight, and its convenience is improved.

Description

Technical Field

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

[0002] Atrial fibrillation is a type of cardiovascular disease, and its main symptoms are sudden rapid heartbeats, which can cause three types of physiological symptoms: dyspnea, weakness, and stroke. Cryoballoon technology and single-point radiofrequency technology have opened a new window for endocardial ablation, but because they can only be used for pulmonary vein isolation, the use of balloons alone is far from enough for persistent and long-term persistent atrial fibrillation. Bilateral pulmonary vein isolation and left atrial linear ablation can fundamentally eliminate the risks of thrombosis and embolism caused by atrial fibrillation. This procedure avoids the median sternotomy of traditional heart surgery, does not require cardiopulmonary bypass (extracorporeal circulation), and avoids radiation damage caused by long-term X-ray exposure. At the same time, the current treatments for intercostal neuralgia are mainly analgesic and anti-inflammatory drug injections and traditional Chinese medicine acupuncture treatment. Cryoablation is a new method for treating persistent pain.

[0003] Existing cryoablation catheters use a method of delivering pre-cooled working fluid to the target location for ablation treatment, which requires that all areas of the entire working fluid delivery pipeline, except for the treatment area, be insulated / cooled, etc., making the catheter relatively bulky; and because the working fluid needs to be cooled to the required temperature before the ablation operation can be performed, it is necessary to equip corresponding equipment such as cold sources and cold pipes, which further increases the number of components and volume, making operation inconvenient. Summary of the Invention

[0004] The present invention provides a cryoablation catheter for solving at least one of the above technical problems.

[0005] The present invention provides a cryoablation catheter, comprising an input tube for conveying a working medium and a cold tube assembly connected to the input tube, wherein the cold tube assembly comprises:

[0006] a cold pipe main, the distal end of which is connected to the input pipe; and

[0007] A cold pipe branch pipe, the cold pipe branch pipe being connected to the proximal end of the cold pipe main pipe, so that the input pipe, the cold pipe main pipe and the cold pipe branch pipe form a working medium input passage;

[0008] There are at least two cold pipe branches, and the diameter of each cold pipe branch is smaller than the diameter of the cold pipe main pipe, so that the distal ends of at least two cold pipe branches can be inserted into the cold pipe main pipe from the proximal end of the cold pipe main pipe at the same time.

[0009] In one embodiment, the proximal end of each cold pipe branch is connected to a capillary tube, and the diameter of each capillary tube is smaller than the diameter of the corresponding cold pipe branch, so that the distal end of each capillary tube can be inserted into the cold pipe branch from the proximal end of the corresponding cold pipe branch.

[0010] In one embodiment, the axes of the cooling pipe branches are parallel to each other, and the axial lengths of the cooling pipe branches increase or decrease in a regular manner.

[0011] In one embodiment, the number of the cold pipe branches is 3, and the 3 cold pipe branches are arranged at equal angles along the circumference of the cold pipe main pipe, so that the outer circumferential surfaces of every 2 of the 3 cold pipe branches are circumscribed respectively, and the outer circumferential surfaces of the 3 cold pipe branches are all inscribed with the inner circumferential surface of the cold pipe main pipe.

[0012] In one embodiment, the cold pipe assembly further comprises an outer pipe, the cold pipe main pipe and the cold pipe branch pipes are both disposed in the outer pipe, and each cold pipe branch pipe is connected to the outer pipe through its proximal end;

[0013] A working medium output passage is formed between the inner wall of the outer tube and the outer wall of the cold tube main tube, and between the inner wall of the outer tube and the outer walls of each cold tube branch tube.

[0014] In one embodiment, a joint assembly is further included, the joint assembly comprising:

[0015] an adapter, wherein a step hole is provided on a first side of the adapter, the outer tube is provided in the step hole, and a distal end surface of the outer tube abuts against a step surface of the step hole; and

[0016] A first connecting piece is provided on the second side of the adapter, and the input pipe is connected to the adapter through the first connecting piece. The distal end of the cold pipe main pipe extends from the distal end of the outer pipe and passes through the adapter, and then extends into the input pipe from the proximal end of the input pipe, so that the cold pipe main pipe is connected to the input pipe.

[0017] In one embodiment, an output pipe is further included, which is connected to a second connecting piece located on a second side of the adapter, and the second connecting piece is connected to the adapter and the working fluid output passage, so that the working fluid output from the working fluid output passage enters the output pipe through the adapter.

[0018] In one embodiment, the adapter is provided with a first connecting hole extending along a first direction, and the cooling pipe main penetrates the first connecting hole and the first connecting piece to be connected with the input pipe;

[0019] The adapter is also provided with a second connecting hole extending along a second direction perpendicular to the first direction. The first connecting hole is respectively connected to the second connecting hole and the step hole. The second connecting hole is connected to the second connecting member. The second connecting member can be connected to the working medium output passage through the second connecting hole.

[0020] In one embodiment, one end of the first connecting member for inserting into the input tube is configured in a pagoda shape, and the other end of the first connecting member extends into the adapter and is sealed and fixedly connected to the adapter;

[0021] One end of the second connecting member for inserting into the output pipe is constructed in a pagoda shape, and the other end of the second connecting member extends into the adapter and is sealed and fixedly connected to the adapter.

[0022] In one embodiment, a handle is further included for accommodating the joint assembly, the distal end of the outer tube extends from a first side of the handle into the handle and is fixed in the handle, and the proximal ends of the output tube and the input tube both extend from a second side of the handle and are fixed in the handle.

[0023] In one embodiment, the cold tube assembly further comprises a protective tube assembly extending from a first side of the handle, the protective tube assembly comprising a first tube sleeved outside the outer tube and covering a non-treatment area of ​​the outer tube, and a second tube sleeved outside the first tube;

[0024] The inner wall of the second tube is provided with at least one recessed portion recessed along its radial direction, and the at least one recessed portion separates the inner wall of the second tube from the outer wall of the first tube to isolate cold energy.

[0025] In one embodiment, a temperature measuring device is further included, and the temperature measuring device extends along the extension direction of the working medium input passage and penetrates into the recessed portion.

[0026] In one embodiment, a bending mark portion is provided on the outer wall of the outer tube, and the tube section between the bending mark portion and the proximal end of the protective tube assembly is a bendable tube section;

[0027] The length of the bendable pipe section is less than or equal to the distance between the proximal end of the protection pipe assembly and the distal end of the capillary tube inserted into the shortest cold pipe branch.

[0028] In one embodiment, the outer tube includes an outer tube made of a first material and an outer tube made of a second material, the outer tube made of the first material and the outer tube made of the second material are respectively made of different metal materials, and the bending mark is located where the outer tube made of the first material and the outer tube made of the second material are connected.

[0029] In one embodiment, a first coating and a second coating are coated on the outer tube respectively, the first coating and the second coating are made of different materials respectively, and the bending mark is located at the place where the first coating and the second coating are connected.

[0030] In one embodiment, a first connector is provided at the distal end of the input tube, and a second connector is provided at the distal end of the output tube. The input tube receives external working fluid through the first connector, and the output tube discharges the treated working fluid out of the cryoablation catheter through the second connector.

[0031] In one embodiment, the device further comprises a wire protection tube extending from the second side of the handle, wherein the input tube, the output tube and the temperature measuring device are arranged side by side in the wire protection tube.

[0032] Compared with the prior art, the advantage of the present invention is that by adopting a method of splitting the cold pipe branch into multiple cold pipe branches, the temperature of the working fluid can quickly drop to the required temperature when it is transported to the target area, so that the corresponding working fluid can be stored and used at room temperature, avoiding equipment such as cold sources and cold pipes, which is conducive to the miniaturization and lightweight of the equipment; in addition, at the far end of the cold pipe branch, components such as the input pipe do not need to be equipped with insulation / insulation components, because the working fluid it transports is room temperature working fluid, and the working fluid can be kept at room temperature before being transported to the cold pipe branch, so there is no need to take special insulation / insulation measures for components such as the input pipe, so the cryoablation catheter can be further miniaturized and lightweight, and its convenience is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Hereinafter, the present invention will be described in more detail based on embodiments with reference to the accompanying drawings.

[0034] Figure 1 is a front view of a cryoablation catheter according to an embodiment of the present invention;

[0035] Figure 2 yes Figure 1 The structure diagram of the cryoablation catheter shown is a schematic diagram of the structure after the wire protection tube and the first handle housing are hidden;

[0036] Figure 3 yes Figure 2 The schematic diagram of the structure of the cryoablation catheter shown is shown with the protective tube assembly and the outer tube hidden;

[0037] Figure 4 yes Figure 3 Enlarged view at E;

[0038] Figure 5 yes Figure 4 Enlarged view at AA;

[0039] Figure 6is a cross-sectional view of a cryoablation catheter according to an embodiment of the present invention;

[0040] Figure 7 yes Figure 6 Enlarged view at N;

[0041] Figure 8 yes Figure 6 Enlarged view at M;

[0042] Figure 9 yes Figure 6 Enlarged view at F;

[0043] Figure 10 yes Figure 1 The cryoablation catheter shown is a schematic diagram of the three-dimensional structure after the wire protection tube and the first handle shell are hidden;

[0044] Figure 11 yes Figure 10 The cryoablation catheter shown is a schematic diagram of the three-dimensional structure after the protective tube assembly and the outer tube are hidden;

[0045] Figure 12 yes Figure 10 Enlarged view at P;

[0046] Figure 13 yes Figure 2 Enlarged view at BB;

[0047] Figure 14 yes Figure 2 A schematic diagram of the three-dimensional structure of the second handle housing is shown;

[0048] Figure 15 yes Figure 2 A front view of the connector assembly is shown;

[0049] Figure 16 yes Figure 2 a cross-sectional view of the connector assembly shown;

[0050] Figure 17 yes Figure 15 a cross-sectional view of the adapter shown;

[0051] Figure 18 is a schematic diagram of the coordination relationship between the second handle housing and various components;

[0052] Figure 19 This is a schematic diagram of the temperature field distribution of the cold pipe branch in an embodiment of the present invention 2 seconds after the start of fluid delivery;

[0053] Figure 20 This is a schematic diagram of the temperature field distribution of the cold pipe branch in an embodiment of the present invention 5 seconds after the start of fluid delivery;

[0054] Figure 21 This is a schematic diagram of the temperature field distribution of the cold pipe branch in an embodiment of the present invention 12 seconds after the start of fluid delivery;

[0055] Figure 22 Schematic diagram of stress field distribution of each cold pipe branch and each capillary tube when the length of each cold pipe branch extending into the cold pipe main tube is 1 mm and the length of each capillary tube extending into the corresponding cold pipe branch tube is 0.5 mm;

[0056] Figure 23 Schematic diagram of the displacement field distribution of each cold pipe branch and each capillary tube when the length of each cold pipe branch extending into the cold pipe main tube is 1 mm and the length of each capillary tube extending into the corresponding cold pipe branch tube is 0.5 mm;

[0057] Figure 24 Schematic diagram of the stress field distribution of each cold pipe branch and each capillary tube when, in a preferred embodiment of the present invention, the length of the cold pipe branch extending into the cold pipe main pipe is 1 / 2 mm of its own length, and the length of each capillary tube extending into the corresponding cold pipe branch is 1 / 2 mm of its own length;

[0058] Figure 25 Schematic diagram of the displacement field distribution of each cold pipe branch and each capillary tube when, in a preferred embodiment of the present invention, the length of the cold pipe branch extending into the cold pipe main pipe is 1 / 2 mm of its own length, and the length of each capillary tube extending into the corresponding cold pipe branch is 1 / 2 mm of its own length;

[0059] Figure 26 This is a schematic diagram of the stress field distribution of the adapter when the cold pipe main is directly connected to the adapter;

[0060] Figure 27 Schematic diagram of the stress field distribution of the cooling pipe main, the first connecting member, and the adapter when a portion of the cooling pipe main is inserted into the first connecting member in a preferred embodiment of the present invention;

[0061] Figure 28 Schematic diagram of the displacement field distribution of the first connecting member and the adapter when a portion of the cooling pipe main is inserted into the first connecting member in a preferred embodiment of the present invention.

[0062] Reference numerals:

[0063] 100, input tube; 110, first connector; 111, male connector; 112, female connector;

[0064] 200, output pipe; 210, second connector;

[0065] 300, wire protection tube;

[0066] 400. Temperature measuring device;

[0067] 500, handle; 510, first handle housing; 520, second handle housing; 530, fixing clamp;

[0068] 531, distal fixing clamp; 532, connector assembly fixing clamp; 533, outer tube fixing clamp; 534, proximal fixing clamp;

[0069] 600, cold pipe assembly;

[0070] 610, cold pipe main;

[0071] 620, cold pipe branch; 621, first cold pipe branch; 622, second cold pipe branch; 623, third cold pipe branch; 624, capillary tube;

[0072] 630, outer tube; 631, bending mark portion; 632, outer tube sealing plug;

[0073] 640, protective tube assembly; 641, first tube; 642, second tube; 643, recessed portion;

[0074] 650, heat shrink tubing;

[0075] 660, casing;

[0076] 700, connector assembly; 710, adapter; 711, stepped hole; 712, first connecting hole; 713, second connecting hole; 714, connecting hole sealing plug; 715, first mounting hole; 716, second mounting hole;

[0077] 720, first connecting member; 730, second connecting member. DETAILED DESCRIPTION

[0078] The present invention will be further described below with reference to the accompanying drawings.

[0079] like Figures 1-18 As shown, the present invention provides a cryoablation catheter that can treat persistent heart disease atrial fibrillation or intercostal neuralgia (pain in a band extending diagonally forward and downward from the chest and back along the intercostals to the midline of the anterior chest and abdominal wall. Severe pain is often caused by herpes zoster, spinal degeneration, lung or abdominal tumor compression, neuritis, etc.) by rapidly cooling the treatment area.

[0080] Specifically, if Figure 1 and Figure 2 As shown, the cryoablation catheter of the present invention includes an input tube 100 for delivering a working medium, a cold tube assembly 600 connected to the input tube 100, and an output tube 200 for delivering the working medium after treatment.

[0081] The cold pipe assembly 600 receives the working fluid from the input tube 100, and rapidly cools down the working fluid flowing to the treatment area of ​​the cold pipe assembly 600 (the temperature of the working fluid close to room temperature can be reduced to minus 40°), and guides the cold energy to the position where the treatment area of ​​the cold pipe assembly 600 contacts, thereby achieving the purpose of completely blocking the myocardial sleeve potential or intercostal nerve point of the pulmonary vein.

[0082] The working fluid of the present invention may be, for example, a gaseous working fluid such as nitrous oxide (laughing gas) or carbon dioxide, which has a wide source and low cost.

[0083] like Figure 2 and Figure 3 As shown, the cold pipe assembly 600 includes a cold pipe main pipe 610, a cold pipe branch pipe 620, and an outer pipe 630 sheathed on the outside of the cold pipe main pipe 610 and the cold pipe branch pipe 620. The distal end of the cold pipe main pipe 610 is connected to the input pipe 100 (see Figure 2 、 Figure 6 and Figure 7 ), so as to receive the working medium from the input pipe 100. The cold pipe branch 620 is connected to the proximal end of the cold pipe main pipe 610 (please refer to Figure 3 and Figure 4 ), so that the input pipe 100, the cold pipe main pipe 610 and the cold pipe branch pipe 620 form a working medium input passage.

[0084] There are at least two cold pipe branches 620, and the diameter of each cold pipe branch 620 is smaller than the diameter of the cold pipe main pipe 610, so that the distal ends of at least two cold pipe branches 620 can be simultaneously inserted into the cold pipe main pipe 610 from the proximal end of the cold pipe main pipe 610.

[0085] Because the diameter of the cold pipe branch 620 is smaller (much smaller) than that of the main cold pipe 610, the working fluid is divided into multiple paths as it flows from the main cold pipe 610 to each cold pipe branch 620, undergoing a first pre-cooling. Due to the Joule-Thomson effect, the temperature of the working fluid flowing into each cold pipe branch 620 will drop rapidly for the first time. Therefore, by dividing the single flow path formed by the main cold pipe 610 into multiple cold pipe branches 620 (i.e., multiple flow branches), the resistance and air resistance within the flow path are reduced, the pressure drop is increased, and thus the cooling power is improved. Furthermore, the additional flow paths also reduce the formation of an airtight seal within the pipe.

[0086] By dividing the cold pipe branch 620 into multiple cold pipe branches 620, the temperature of the working fluid can drop rapidly after entering the multiple cold pipe branches 620, while the temperature can be maintained within the room temperature range before entering the cold pipe branch 620. Therefore, at the distal end of the cold pipe branch 620, for example, the input pipe 100 and other components, there is no need to set up insulation / cooling components, because the working fluid it transports is room temperature working fluid, and the working fluid can be maintained at room temperature (or slightly lower / higher than room temperature) before being transported to the cold pipe branch 620. Therefore, there is no need to take special insulation / cooling measures for components such as the input pipe 100, and the cryoablation catheter can be miniaturized and lightweight. In addition, there is no need to use already cooled cold working fluid, but pre-cooling is performed during treatment, so that the corresponding working fluid can also be stored and used at room temperature, which improves its convenience.

[0087] Furthermore, if Figure 4 and Figure 9 As shown, the proximal end of each cold pipe branch 620 is connected to a capillary tube 624. The diameter of each capillary tube 624 is smaller than that of the corresponding cold pipe branch 620, allowing the distal end of each capillary tube 624 to be inserted into the cold pipe branch 620 from the proximal end of the corresponding cold pipe branch 620. Because the diameter of the capillary tube 624 is smaller than that of the cold pipe branch 620, the working fluid flowing from the cold pipe branch 620 into the capillary tube 624 undergoes a second pre-cooling. Similar to the first pre-cooling described above, the Joule-Thomson effect further reduces the temperature of the working fluid flowing from the cold pipe branch 620 into the capillary tube 624, for example, to as low as 40°C.

[0088] Therefore, the present invention uses pre-cooling, utilizing multi-branch zonal cooling, to rapidly improve cooling efficiency. Experimental studies have shown that using multi-branch pre-cooling can reduce the working fluid temperature from room temperature to 0°C within 3 seconds and to therapeutic temperature within 8 seconds. Surgery can be completed by maintaining the therapeutic temperature for less than 5 minutes, significantly reducing the duration of thoracotomy and minimizing the risks of infection and cardiopulmonary resuscitation associated with prolonged thoracotomy.

[0089] It should be noted that the "proximal end" mentioned herein refers to the end close to the target area for treatment (e.g. Figure 1 The distal end refers to the end close to the host or cold source, that is, the end away from the patient to be treated (as shown in FIG Figure 1 shown).

[0090] In some preferred embodiments, Figure 4 As shown, the axes of the cooling pipe branches 620 are parallel to each other, and the axial lengths of the cooling pipe branches 620 increase or decrease in a regular manner.

[0091] In some preferred embodiments, the preferred number of the cold pipe branch pipes 620 is obtained by means of computer simulation analysis (temperature field simulation analysis). Specifically, first, a three-dimensional model is established, in which the numbers of the cold pipe branch pipes 620 are 1, 2, and 3 respectively. Subsequently, it is imported into analysis software for analysis.

[0092] The analysis results show that under the same conditions, when the number of the cold pipe branch pipes 620 is 3, the temperature of the fluid therein is lower (for example Figure 21 the temperature at the proximal end of the cold pipe branch pipe 620 can reach -80° or a lower temperature), and the refrigeration efficiency and speed are also optimal. Therefore, preferably, the number of the cold pipe branch pipes 620 is 3.

[0093] As Figures 19-21 shown by the analysis results, when the number of the cold pipe branch pipes 620 is 3, after the fluid 2 is transported for 2 s, the temperature around the cold pipe branch pipe 620 can reach about -30°; after the fluid is transported for 5 s, the temperature around the cold pipe branch pipe 620 can reach about -50° (at this time, the treatment requirement of -40° is satisfied); after the fluid is transported for 12 s, the lowest temperature around the cold pipe branch pipe 620 can reach about -80°. Therefore, under the same conditions, when the number of the cold pipe branch pipes 620 is 3, the temperature of the fluid therein is lower (for example Figure 21 the temperature at the proximal end of the cold pipe branch pipe 620 can reach -80° or a lower temperature), and the refrigeration efficiency and speed are also optimal.

[0094] In addition, the 3 cold pipe branch pipes 620 can be arranged in a "pin" shape in the cold pipe main pipe 610, so as to maximize the occupation of the internal space in the cold pipe main pipe 610, maximize the utilization rate of the internal space in the cold pipe main pipe 610; and a structure symmetric in the circumferential direction can be formed by the above arrangement method, so as to improve its strength and force uniformity.

[0095] The following takes the number of the cold pipe branch pipes 620 being 3 as an example for illustration.

[0096] Please refer to Figure 4 、 Figure 5 、 Figure 9 and Figure 13 . The cold pipe branch pipe 620 includes a first cold pipe branch pipe 621, a second cold pipe branch pipe 622, and a third cold pipe branch pipe 623. Capillaries 624 are provided at the proximal ends of the first cold pipe branch pipe 621, the second cold pipe branch pipe 622, and the third cold pipe branch pipe 623. Among them, the distal ends of the capillaries 624 extend from the proximal ends of the respective cold pipe branch pipes 620 into them, and the proximal ends of the capillaries 624 extend outside the respective cold pipe branch pipes 620.

[0097] The relationship among the length l1 of the first cooling pipe branch 621, the length l2 of the second cooling pipe branch 622, and the length l3 of the third cooling pipe branch 623 is: l1 < l2 < l3. That is, the length l1 of the first cooling pipe branch 621 is the smallest, and the length l3 of the third cooling pipe branch 623 is the largest.

[0098] Furthermore, l2-l1=l3-l2, that is, the length difference between the second cold pipe branch 622 and the first cold pipe branch 621 is equal to the length difference between the third cold pipe branch 623 and the second cold pipe branch 622. Figure 9 As shown, preferably, l2-l1=l3-l2=19.5 mm, that is, a uniform and gradient length difference is formed between the cooling pipe branches.

[0099] The length difference between each cold tube branch can be determined by the length (in the axial direction) of the effective treatment area at the proximal end of each cold tube branch. Figure 21 As shown, the computer simulation results (temperature field simulation analysis) of the cryoablation catheter of the present invention show that the length differences between the branches of the cold tube are uniform and gradient, which can make the fluid flow more stable and help to obtain a uniform and more consistent cold zone (see Figure 21 The temperature near and around each cold pipe branch is roughly within the range of -70°. The temperature distribution near and around each cold pipe branch is relatively uniform, and the temperature difference does not exceed ±10°), which is conducive to ensuring the temperature stability of the treatment area and achieving good treatment effects.

[0100] It should be noted that, for ease of understanding, the length l1 of the first cold pipe branch 621 mentioned above can be the distance between the distal end of the first cold pipe branch 621 and the proximal end thereof. Since the proximal end of the first cold pipe branch 621 is inserted with the capillary tube 624, the length l1 of the first cold pipe branch 621 can also be the distance between the distal end of the first cold pipe branch 621 and the proximal end of the capillary tube 624 inserted therein (e.g., Figure 4 and Figure 9 The length l2 of the second cooling pipe branch 622 and the length l3 of the third cooling pipe branch 623 are similar and will not be described in detail.

[0101] Since the working fluid ejected from the proximal end of the capillary tube 624 can lower the temperature in the interval where it is located, if the lengths of the cold pipe branches 620 are the same, the following phenomenon will occur: the temperature of the proximal end (end) of each cold pipe branch 620 and the proximal end of the capillary tube 624 will be lower, while the temperature of the middle part of each cold pipe branch 620 will be higher, thereby making the cooling amount of the treatment area corresponding to each cold pipe branch 620 unbalanced and forming uneven ice cubes or ice bodies in the treatment area.

[0102] To solve the above problems, the present invention adopts the technical solution of setting the lengths of the first cold pipe branch 621, the second cold pipe branch 622, and the third cold pipe branch 623 to increase gradually in gradient. Then, the working medium ejected from the capillary 624 of the first cold pipe branch 621 can guide the cooling capacity to the part of the second cold pipe branch 622 that is longer than the first cold pipe branch 621 (the middle area of the second cold pipe branch 622), so that the temperature of this part is maintained at a temperature similar to the interval where the working medium ejected from the proximal end of the capillary 624 of the second cold pipe branch 622 is located; thus, the temperature in the overall length direction of the second cold pipe branch 622 is relatively uniform and approximate, and there will be no situation where the temperature at the proximal end (end) is lower while the temperature of other parts is higher. Similarly, the working medium ejected from the capillary 624 of the second cold pipe branch 622 can guide the cooling capacity to the part of the third cold pipe branch 623 that is longer than the second cold pipe branch 622 (the middle area of the third cold pipe branch 623), so that the temperature of this part is maintained at a temperature similar to the interval where the working medium ejected from the proximal end of the capillary 624 of the third cold pipe branch 623 is located; thus, the temperature in the overall length direction of the third cold pipe branch 623 is relatively uniform and approximate. That is to say, by setting the lengths of each cold pipe branch 620 to increase gradually in gradient, the working medium ejected from the capillary of the first cold pipe branch 621 can ensure that the temperature of the part in the middle area of the second cold pipe branch 622 is basically the same as that of its proximal end (end) part, and the working medium ejected from the capillary of the second cold pipe branch 622 can ensure that the temperature of the part in the middle area of the third cold pipe branch 623 and its proximal end (end) part is basically the same, that is, the temperature in the length direction of each cold pipe branch 620 is basically kept the same. Therefore, the cooling capacity can be utilized maximally, and the temperature on each cold pipe branch 620 can be maintained within a relatively uniform range. Therefore, the balance of the cooling capacity in the treatment area can be ensured, so that the cell inactivation time of each part to be treated is relatively consistent, and the phenomena of over-ablation or incomplete ablation can be avoided.

[0103] As Figure 5 and Figure 13 shown, the 3 cold pipe branches 620 can be arranged at equal angles along the circumferential direction of the cold pipe main pipe 610, so that the outer circumferential surfaces of every two of the 3 cold pipe branches 620 are externally tangent to each other, and the outer circumferential surfaces of the 3 cold pipe branches 620 are all internally tangent to the inner circumferential surface of the cold pipe main pipe 610. That is, the 3 cold pipe branches 620 can form a "pin" - shaped structure, thereby maximizing the utilization of the space inside the cold pipe main pipe 610.

[0104] The gaps between the three cold pipe branches 620 and the main cold pipe 610 can be filled with adhesive to secure the three cold pipe branches 620 to the main cold pipe 610. During installation, the three cold pipe branches 620 can be secured in a "pin" shape using a fixing device such as heat shrink tubing, and then inserted as a whole into the proximal end of the main cold pipe 610.

[0105] In order to uniformly receive the working medium in the cooling pipe main 610, the distal ends of the cooling pipe branches 620 (i.e., the ends inserted into the cooling pipe main 610) are aligned with each other. Figure 9 The connection strength between the cold pipe branch 620 and the cold pipe main 610 must be ensured, and the influence of factors such as flow rate and flow velocity must also be considered. Preferably, the depth d to which each cold pipe branch 620 is inserted into the cold pipe main 610 is 1 / 4, 1 / 3, or 1 / 2 of the length of each cold pipe branch 620. More preferably, the depth d to which each cold pipe branch 620 is inserted into the cold pipe main 610 is 1 / 2 of the length of each cold pipe branch 620. Similarly, the length of each capillary tube 624 extending into the corresponding cold pipe branch is 1 / 3 or 1 / 2 of the length of each capillary tube 624. More preferably, the length of each capillary tube 624 extending into the corresponding cold pipe branch is 1 / 2 of the length of each capillary tube 624.

[0106] When the length of each cold pipe branch 620 extending into the cold pipe main pipe 610 is short (i.e., only a small portion of each cold pipe branch extends into the cold pipe main pipe 610, for example, the length of each cold pipe branch 620 extending into the cold pipe main pipe 610 is less than or equal to 1 mm), and the length of each capillary tube 624 extending into the corresponding cold pipe branch 620 is short (e.g., the length of each capillary tube 624 extending into the corresponding cold pipe branch is less than or equal to 0.5 mm), as shown in FIG. Figure 22 and Figure 23 As shown, computer simulation analysis (stress analysis) shows that each cold pipe branch 620 and each capillary tube 624 is subjected to large stress and has a large displacement. Some capillary tubes 624 have even separated from their corresponding cold pipe branches 620 (e.g. Figure 23 As shown in the figure), it will cause the fluid to leak and spray out.

[0107] Computer simulation analysis (stress analysis) is performed with the depth d of each cold pipe branch 620 inserted into the cold pipe main pipe 610 being 1 / 2 of the length of each cold pipe branch 620 itself, and the length of each capillary tube 624 extending into the corresponding cold pipe branch being 1 / 2 of the length of each capillary tube 624 itself. Figure 24 and Figure 25 As shown, the stress and displacement of each cold pipe branch 620 and each capillary tube 624 are within a controllable range.

[0108] The number of cold pipe branches 620 can also be two, and the two cold pipe branches 620 can be arranged side by side. To conform to the shape of the two cold pipe branches 620 when arranged side by side, the cold pipe main 610 can be configured as a cylindrical structure with an elliptical cross-section. Specifically, the cold pipe main 610 can be configured as a cylindrical structure with an elliptical cross-section as a whole, or only the portion connected to the two cold pipe branches 620 can be configured as a cylindrical structure with an elliptical cross-section, while the remaining portion can be configured as a cylindrical structure to facilitate coordination and installation.

[0109] The number of the cold pipe branches 620 can also be four, and the four cold pipe branches 620 can be arranged side by side in pairs, and the cold pipe main pipe 610 can be correspondingly configured as a columnar structure with a rounded rectangular cross-section in whole or in part.

[0110] The number of the cold pipe branches 620 may be other numbers, and the cold pipe main 610 may be other structural forms, which are not limited in the present invention.

[0111] Please continue to see Figure 2 and Figure 3 The cold pipe assembly 600 also includes an outer pipe 630, in which the cold pipe main pipe 610 and the cold pipe branch pipe 620 are both arranged, and each cold pipe branch pipe 620 is connected to the outer pipe 630 through its proximal end; a working medium output passage is formed between the inner wall of the outer pipe 630 and the outer wall of the cold pipe main pipe 610, and between the inner wall of the outer pipe 630 and the outer wall of each cold pipe branch pipe 620.

[0112] like Figure 6 As shown, the proximal end of the outer tube 630 is provided with an outer tube sealing plug 632, which seals the proximal end of the outer tube 630. Since the proximal end of each capillary tube 624 is an open end, the working fluid ejected from the proximal end of each capillary tube 624 enters the outer tube 630 and returns at the proximal end of the outer tube 630.

[0113] Because each cold pipe branch 620 extends from the proximal interior of the cold pipe main pipe 610, the aforementioned working fluid output path can include the following components: a first working fluid output path between the outer wall of each cold pipe branch 620 and the inner wall of the outer pipe 630, a second working fluid output path between the outer wall of the cold pipe main pipe 610 and the inner wall of the outer pipe 630, a third working fluid output path, a fourth working fluid output path, and the output pipe 200. The third and fourth working fluid output paths will be described in detail below. The working fluid after treatment can be output to the output pipe 200 through the working fluid output path and discharged out of the cryoablation catheter.

[0114] It can be understood that the flow direction of the working fluid in the working fluid output passage is opposite to the flow direction of the working fluid in the working fluid input passage.

[0115] In some preferred embodiments, the cryoablation catheter of the present invention further comprises a handle 500 , wherein a connector assembly 700 is disposed inside the handle 500 . The connector assembly 700 comprises an adapter 710 , a first connector 720 , and a second connector 730 .

[0116] like Figure 15 、 Figure 16 and Figure 17 As shown, please combine Figure 6 、 Figure 7 and Figure 8 The adapter 710 has a stepped hole 711 on its first side. The outer tube 630 is disposed in the stepped hole 711, with the distal end of the outer tube 630 abutting against the stepped surface of the stepped hole 711. A first mounting hole 715 and a second mounting hole 716 are provided on the second side of the adapter 710. The first connector 720 is disposed in the first mounting hole 715, and the second connector 730 is disposed in the second mounting hole 716. The axes of the first mounting hole 715 and the second mounting hole 716 are parallel to each other, so the first connector 720 and the second connector 730 are disposed substantially in parallel.

[0117] like Figure 17 As shown, adapter 710 is provided with a first connection hole 712 extending in a first direction (horizontally) and a second connection hole 713 extending in a second direction (vertically) perpendicular to the first direction. First mounting hole 715 and stepped hole 711 are coaxial, and first mounting hole 715, second mounting hole 716, first connection hole 712, and second connection hole 713 are interconnected, that is, adapter 710 itself has a three-way structure.

[0118] like Figure 7 and Figure 8 As shown, the input tube 100 is connected to the adapter 710 via a first connector 720. Specifically, one end of the first connector 720 is inserted into the proximal end of the input tube 100. To ensure smooth insertion and a good seal between the two, the end of the first connector 720 for insertion into the input tube 100 is constructed in a pagoda shape (i.e., the outer wall of the first connector 720 is sequentially provided with multiple inclined steps). The other end of the first connector 720 extends into the first mounting hole 715 of the adapter 710 and is sealed and fixedly connected thereto. More specifically, the first connector 720 and the adapter 710 can be locked and secured using a rubber clamp.

[0119] Furthermore, if Figure 7 and Figure 8As shown, the distal end of the cold pipe main pipe 610 extends from the distal end of the outer pipe 630 and passes through the first connecting hole 712 and the first connecting member 720 of the adapter 710 in sequence, and then extends into the input pipe 100 from the proximal end of the input pipe 100, so that the cold pipe main pipe 610 is connected with the input pipe 100, so that the working fluid in the input pipe 100 can flow into the cold pipe main pipe 610.

[0120] The present invention connects the cooling pipe main 610 by inserting a portion of the cooling pipe main 610 into the first connecting piece 720 .

[0121] In some embodiments, the cold pipe main 610 does not extend into the first connector 720 but is directly connected to the adapter 710. In this case, the adapter 710 will be subjected to greater strain. Since the gas pressure of the input pipe 100 for normal fluid input is between 5 MPa and 6 MPa, under such strain, the adapter 710 made of PC material may crack and leak. Figure 26 As shown, a stress analysis of adapter 710 in this case reveals that stress is concentrated at the first mounting hole 715, potentially damaging the PC adapter 710. Using metal for adapter 71 would increase costs and consumable weight, making it difficult to operate during surgery. Conversely, inserting a portion of the cooling pipe main 610 into the first connector 720 provides a safer and more reliable connection.

[0122] like Figure 27 and Figure 28 Figure 2 shows the results of a computer simulation analysis (stress analysis) of a solution where a portion of the cooling pipe main 610 is inserted into the first connector 720. The results demonstrate that while pressure acts on both the cooling pipe main 610 and the first connector 720, the adapter 710 experiences less pressure and minimal displacement. This allows the adapter 710 to remain constructed of PC, effectively mitigating safety risks and reducing product weight. This balance between strength and weight is achieved, achieving optimal force and displacement when directly acting on the cooling pipe main 610.

[0123] Preferably, computer simulation analysis (strength analysis) is performed on the cryoablation catheter of the present invention, and combined with the requirements of processability, the length of the cold pipe main 610 inserted into the first connector 720 can be set to 3 mm. Figure 7 and Figure 8 As shown, the output tube 200 is connected to the adapter 710 through the second connecting piece 730. Figure 15 and Figure 16One end of the second connecting member 730 is inserted into the proximal end of the output tube 200. In order to ensure smooth insertion and good sealing between the two, the end of the second connecting member 730 for inserting into the output tube 200 is constructed in a pagoda shape (that is, a plurality of inclined steps are sequentially provided on the outer wall of the second connecting member 730). The other end of the second connecting member 730 extends into the second mounting hole 716 of the adapter 710 and is sealed and fixedly connected to the second mounting hole 716 of the adapter 710.

[0124] The second connecting member 730 is connected to the adapter 710 and the working medium output passage, so that the working medium output from the working medium output passage enters the output pipe 200 through the adapter 710 .

[0125] Understandably, if Figure 8 As shown, the distal end surface of the outer tube 630 abuts against the step surface of the step hole 711, and the cold pipe main tube 610 extends from the distal end of the outer tube 630 and extends through the first connecting hole 712 and the first connecting member 720 in sequence. The flow path between the outer wall of the cold pipe main tube 610 and the inner wall of the first connecting hole 712 constitutes the third working fluid output path. Since the second connecting hole 713 is connected to the first connecting hole 712, the second connecting hole 713 constitutes the fourth working fluid output path.

[0126] Please refer to Figure 8 The first connecting piece 720 can extend into the first mounting hole 715 of the adapter 710 and be sealed and fixedly connected to the first mounting hole 715 of the adapter 710, while the cold pipe main 610 passes through the first connecting piece 720. Therefore, the first connecting piece 720 blocks the passage between the first mounting hole 715 and the first connecting hole 712. Then, the working fluid flowing through the third working fluid output passage cannot enter the first mounting hole 715 or the first connecting piece 720, but can only enter the fourth working fluid output passage. The second connecting hole 713 is respectively connected to the second connecting piece 730 and the output pipe 200. Therefore, the working fluid entering the fourth working fluid output passage can enter the output pipe 200 through the second connecting piece 730 and can be output from the output pipe 200 to the outside of the cryoablation tube. Therefore, the adapter 710 of the present invention can achieve physical isolation of the flow paths of the input working fluid and the output working fluid, ensuring the safety of working fluid transportation.

[0127] Since the axes of the first connecting hole 712 and the second connecting hole 713 are perpendicular to each other, in order to reduce the difficulty of processing, the upper end of the second connecting hole 713 can be processed into an open end first during processing. Figure 17 During installation, a connection hole sealing plug 714 is provided at the upper end of the second connection hole 713, as shown in FIG. Figure 16 As shown, the second connecting hole 713 can be formed into a closed channel.

[0128] The handle 500 accommodates the adapter 710, the proximal end of the input tube 100, the proximal end of the output tube 200, and the distal ends of the outer tube 630 and the cold tube main tube 610. Figure 2 and Figure 3 The distal end of the outer tube 630 extends from the first side of the handle 500 into the handle 500 and is fixed in the handle 500 , and the proximal ends of the output tube 200 and the input tube 100 both extend from the second side of the handle 500 and are fixed in the handle 500 .

[0129] To facilitate installation, the handle 500 can be constructed as a split structure, namely, comprising a first handle housing 510 and a second handle housing 520 that interlock together. When the two are engaged, a cavity is formed inside the handle 500 to accommodate the aforementioned components. To facilitate securing the aforementioned components within the handle 500, a corresponding fixing ring 530 can be provided within the cavity. The inner diameter of the ring is roughly the same as the outer diameter of each component, so that each component can be secured within the handle 500 by passing through the corresponding fixing ring 530.

[0130] like Figure 14 As shown, the second handle housing 520 is taken as an example for description. The first handle housing 510 can be configured accordingly based on the second handle housing 520.

[0131] The second handle housing 520 is a generally cylindrical structure, with its central portion protruding outward to increase the space within the corresponding cavity, thereby accommodating the connector assembly 700. It is provided with multiple fixing rings 530, including a distal fixing ring 531, a proximal fixing ring 534, a connector assembly fixing ring 532, and an outer tube fixing ring 533. The distal fixing ring 531, the proximal fixing ring 534, and the cold tube fixing ring 533 are generally annular structures.

[0132] The distal fixing clamp 531 is used to fix the input pipe 100 and the output pipe 200. More specifically, since the external portion of the input pipe 100 and the output pipe 200 is also provided with a wire protection tube 300, which is a corrugated tube, the distal fixing clamp 531 can be inserted into the groove on the outer wall of the wire protection tube 300 (e.g., Figure 18 ), thereby securing it in the handle 500.

[0133] Please continue to see Figure 14 and Figure 18 The connector assembly fixing ring 532 is used to fix the connector assembly 700, which can have a structure that roughly matches the adapter 710 and fixes a portion of the input pipe 100 and the output pipe 200 connected to the first connector 720 and the second connector 730 respectively.

[0134] The outer tube fixing ring 533 is used to fix the portion of the outer tube 630 extending into the handle 500. In order to protect the outer tube 630, the outer side of the portion of the outer tube 630 extending into the handle 500 is covered with a heat shrink tube 650 (such as Figure 7 As shown), the outer tube fixing clamp 533 can clamp the heat shrink tube 650 in the handle 500 to fix the outer tube 630.

[0135] The proximal fixing ring 534 is used to fix the sleeve 660. The outer wall of the protective tube assembly 640 that extends into the handle 500 is covered with the sleeve 660. Since the protective tube assembly 640 only needs to protect the corresponding treatment area (such as the outer tube 630 outside the handle 500) Figure 2 As shown), the protective tube assembly 640 only needs to extend into a portion of the handle 500, and the sleeve 660 can play a role in reinforcement and protection.

[0136] like Figure 10 、 Figure 12 and Figure 13 As shown, the cryoablation catheter of the present invention also includes a protective tube assembly 640 extending from the first side of the handle 500, and the protective tube assembly 640 includes a first tube 641 that is sleeved on the outside of the outer tube 630 and covers the non-treatment area of ​​the outer tube 630, and a second tube 642 that is sleeved on the outside of the first tube 641.

[0137] The inner wall of the second tube 642 is provided with at least one recessed portion 643 recessed along its radial direction. The at least one recessed portion 643 separates the inner wall of the second tube 642 from the outer wall of the first tube 641 to isolate the cooling energy. Figure 13 As shown, the inner wall of the second tube 642 is provided with four recessed portions 643 recessed along its radial direction, and correspondingly has four protruding claws, which are in contact with the outer wall of the first tube 641, and the recessed portions 643 are separated from the outer wall of the first tube 641, so that it can not only isolate the cold, but also provide space for accommodating the temperature measuring device 400 described below.

[0138] like Figure 6 、 Figure 12 and Figure 13 As mentioned above, the cryoablation catheter of the present invention further includes a temperature measuring device 400, which extends along the extension direction of the working medium input passage and penetrates into the above-mentioned recessed portion 643. Figure 6 As shown, the distal end of the temperature measuring device 400 can be enclosed in the wire protection tube 300 together with the input tube 100 and the output tube 200; Figure 10 、 Figure 11 and Figure 12 As shown, the proximal portion of the temperature measuring device 400 may be enclosed between a first tube 641 and a second tube 642 .

[0139] The temperature measuring device 400 may be, for example, a thermocouple.

[0140] Furthermore, if Figure 9 As shown, the outer wall of the outer tube 630 is provided with a bend mark 631. The tube section between the bend mark 631 and the proximal end of the protective tube assembly 640 is a bendable tube section. Therefore, for a specific target location, a special bending tool can be used to bend or bend the cryoablation catheter of the present invention at the bend tube section.

[0141] It should be noted that if Figure 9 As shown, the length of the bendable pipe section should be less than or equal to the distance C between the proximal end of the protective tube assembly 640 and the distal end of the capillary 624 inserted into the shortest cold pipe branch 620, so as to avoid bending at the second cold pipe branch 622 or the third cold pipe branch 623 and causing damage to other capillaries 624.

[0142] Since each cold pipe branch 620 is covered inside the outer pipe 630, in order to conveniently observe the range of the bendable pipe section from the outside, the following solutions can be adopted.

[0143] First, outer tube 630 comprises a first outer tube made of a first material and a second outer tube made of a second material, each made of a different metal material. Bend identification portion 631 is located where the first outer tube 630 and the second outer tube 630 meet. Due to the different properties of the first and second outer tubes, bendable tube sections can be quickly and conveniently identified.

[0144] Second, outer tube 630 is coated with a first coating and a second coating, each made of different materials. Bend identification portion 631 is located where the first and second coatings meet. For example, the first coating, which may be a Teflon coating (black or green), is applied to the corresponding bendable tube segment on outer tube 630. Other portions of outer tube 630 may be coated with a second coating, which may be a parylene coating (silver or white), thereby quickly and conveniently identifying the bendable tube segments.

[0145] In addition, the outer tube 630 may be coated with coatings such as parylene and epoxy resin. Since the outer tube 630 needs to be in contact with the tissue of the patient being treated, the above coatings can ensure that the outer tube 630 can be smoothly removed from the treated tissue after treatment without causing adhesion between the outer tube 630 and the tissue, thereby reducing the occurrence of secondary risks.

[0146] Parylene is a family of thermoplastic polymers synthesized from para-xylene. Currently available types include N, C, D, and HT (the structural formulas are shown below), as well as F, diXA, and AM. Experiments have shown that N primarily provides low-friction lubrication, while HT and F types can withstand temperatures exceeding 150°C and maintain long-term use under these conditions. C and D types offer better overall performance and can withstand temperatures below -150°C. Therefore, considering all factors, C is the preferred type.

[0147]

[0148] For further information, please refer to Figure 1 The distal end of the input tube 100 is provided with a first connector 110, and the distal end of the output tube 200 is provided with a second connector 210. The input tube 100 receives the external working fluid through the first connector 110, and the output tube 200 discharges the working fluid after treatment out of the cryoablation catheter through the second connector 210. The first connector 110 includes a male connector 111 and a female connector 112. The male connector 111 is connected to the end of the input tube 100, and the female connector 112 is connected to the working fluid regulating main unit. The male connector 111 and the female connector 112 can be quickly plugged in.

[0149] In order to facilitate bending, the outer tube 630 can be made of metal materials such as copper and aluminum. Alternatively, the outer tube 630 can also be made of stainless steel.

[0150] In addition, the first connecting member 720 and the second connecting member 730 in the joint assembly 700 described above are both made of stainless steel (ferritic stainless steel). The adapter 710 and the connection hole sealing plug 714 in the joint assembly 700 can be made of PC.

[0151] The wire protection tube 300 is made of PU, and the input tube 100 and the output tube 200 are made of nylon. Therefore, the distal end of the cryoablation catheter of the present invention can be bent into other shapes as needed, and does not necessarily have to be as Figure 1 The U shape shown.

[0152] The first handle housing 510 and the second handle housing 520 are made of ABS, the first tube 641 and the second tube 642 are made of PET, and the first joint 110 and the second joint 210 are made of stainless steel.

[0153] The cooling pipe main pipe 610 , each cooling pipe branch pipe 620 , and each capillary tube 624 are all made of stainless steel.

[0154] While the present invention has been described with reference to preferred embodiments, various modifications may be made and equivalent components may be substituted without departing from the scope of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner, provided no structural conflicts exist. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A cryoablation catheter, characterized in that: It includes an input pipe for conveying a working medium and a cold pipe assembly connected to the input pipe. The working medium conveyed by the input pipe is a room temperature working medium. The cold pipe assembly includes: a cold pipe main, the distal end of which is connected to the input pipe; and A cold pipe branch pipe, the cold pipe branch pipe being connected to the proximal end of the cold pipe main pipe, so that the input pipe, the cold pipe main pipe and the cold pipe branch pipe form a working medium input passage; There are three cold pipe branches, each having a diameter smaller than that of the main cold pipe pipe, so that the distal ends of at least two of the cold pipe branches can be simultaneously inserted into the main cold pipe pipe from the proximal end of the main cold pipe pipe; the three cold pipe branches are arranged at equal angles along the circumference of the main cold pipe pipe, so that the outer circumferential surfaces of every two of the three cold pipe branches are circumscribed, and the outer circumferential surfaces of all three cold pipe branches are inscribed with the inner circumferential surface of the main cold pipe pipe; The cold pipe branch includes a first cold pipe branch, a second cold pipe branch and a third cold pipe branch. The length of the first cold pipe branch is l 1. The length of the second cooling pipe branch l 2 and the length of the third cooling pipe branch l The relationship between the 3 is: l 1< l 2< l 3, and l 2- l 1= l 3- l 2; The cold pipe assembly further includes an outer pipe, the cold pipe main pipe and the cold pipe branch pipes are both arranged in the outer pipe, and each cold pipe branch pipe is connected to the outer pipe through its proximal end; A working medium output passage is formed between the inner wall of the outer tube and the outer wall of the cold tube main tube, and between the inner wall of the outer tube and the outer walls of each cold tube branch tube.

2. The cryoablation catheter according to claim 1, characterized in that The proximal end of each cold pipe branch is connected to a capillary tube, and the diameter of each capillary tube is smaller than the diameter of the corresponding cold pipe branch, so that the distal end of each capillary tube can be inserted into the cold pipe branch from the proximal end of the corresponding cold pipe branch.

3. The cryoablation catheter according to claim 1 or 2, characterized in that: The axes of the cooling pipe branches are parallel to each other.

4. The cryoablation catheter according to claim 1, characterized in that Also included is a joint assembly, the joint assembly comprising: an adapter, wherein a step hole is provided on a first side of the adapter, the outer tube is provided in the step hole, and a distal end surface of the outer tube abuts against a step surface of the step hole; and A first connecting piece is provided on the second side of the adapter, and the input pipe is connected to the adapter through the first connecting piece. The distal end of the cold pipe main pipe extends from the distal end of the outer pipe and passes through the adapter, and then extends into the input pipe from the proximal end of the input pipe, so that the cold pipe main pipe is connected to the input pipe.

5. The cryoablation catheter according to claim 4, characterized in that The adapter further includes an output pipe connected to a second connector located on a second side of the adapter, the second connector communicating with the adapter and the working fluid output passage, such that the working fluid output from the working fluid output passage enters the output pipe through the adapter; The adapter is provided with a first connecting hole extending along a first direction, and the cooling pipe main penetrates the first connecting hole and the first connecting piece to be connected with the input pipe; The adapter is also provided with a second connecting hole extending along a second direction perpendicular to the first direction. The first connecting hole is respectively connected to the second connecting hole and the step hole. The second connecting hole is connected to the second connecting member. The second connecting member can be connected to the working medium output passage through the second connecting hole.

6. The cryoablation catheter according to claim 5, characterized in that The invention also includes a handle for accommodating the joint assembly, wherein the distal end of the outer tube extends from a first side of the handle into the handle and is fixed in the handle, and the proximal ends of the output tube and the input tube both extend from a second side of the handle and are fixed in the handle.

7. The cryoablation catheter according to claim 6, characterized in that The cold tube assembly further includes a protective tube assembly extending from a first side of the handle, the protective tube assembly including a first tube sleeved outside the outer tube and covering a non-treatment area of ​​the outer tube, and a second tube sleeved outside the first tube; The inner wall of the second tube is provided with at least one recessed portion recessed along its radial direction, and the at least one recessed portion separates the inner wall of the second tube from the outer wall of the first tube to isolate cold energy.

8. The cryoablation catheter according to claim 7, characterized in that It also includes a temperature measuring device, which extends along the extension direction of the working medium input passage and penetrates into the recessed portion.

9. The cryoablation catheter according to claim 7, characterized in that A bending mark portion is provided on the outer wall of the outer tube, and the tube section between the bending mark portion and the proximal end of the protective tube assembly is a bendable tube section; The length of the bendable pipe section is less than or equal to the distance between the proximal end of the protection pipe assembly and the distal end of the capillary tube inserted into the shortest cold pipe branch.

10. The cryoablation catheter according to claim 9, characterized in that The outer tube is coated with a first coating and a second coating respectively, the first coating and the second coating are made of different materials respectively, and the bending mark is located at the place where the first coating and the second coating are connected.

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