A cryoablation catheter and ablation system

Abstract

The application belongs to the technical field of medical devices, and particularly relates to a kind of cryoablation catheter and ablation system, the cryoablation catheter includes inner catheter and outer catheter, the outer catheter is coaxially sleeved on the outside of inner catheter, the inner catheter is configured as a multi-lumen structure, further comprising: a plurality of sealing components, a plurality of the sealing components are arranged on the outside of inner catheter;Wherein, in the initial state, a plurality of the sealing components and inner catheter are located in the inside of outer catheter, in the working state, a plurality of the sealing components and intestinal wall form an ablation closed space together. The application guides the cryoablation catheter to the target position through the guide wire, forms the ablation closed space through the cooperation of sealing components and lumen wall, inputs the cryogenic medium into the ablation closed space to freeze and ablate the lumen wall, provides a usable treatment plan for type 2 diabetes, obesity or other lumen lesion patients, and has the advantages of small trauma, less pain for patients, low surgical risk, etc.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a cryoablation catheter and ablation system. Background Technology

[0002] For patients with type 2 diabetes and obesity, the most common treatments are medication and surgery. Medication for type 2 diabetes may not respond well to traditional drug therapy in some patients. Medication for obesity often causes adverse reactions that affect patients' lives. Surgical treatments, such as gastric bypass surgery and sleeve gastrectomy, carry a high risk of surgical and postoperative complications and are generally expensive. Studies have shown that duodenal mucosal remodeling (DMR), as a novel minimally invasive treatment, can be effective in treating type 2 diabetes and obesity in certain cases. This provides an option for many patients who do not respond well to traditional medications or cannot undergo traditional surgery. Currently, DMR products using hydrothermal, steam, and IRE methods have been disclosed. This patent proposes a cryoablation catheter for mucosal remodeling, aiming to perform DMR surgery via cryoablation, thus providing patients with another treatment option. Summary of the Invention

[0003] The purpose of this invention is to provide a cryoablation catheter, which is guided to the target location by a guidewire. An ablation sealed space is formed by the cooperation of the sealing component and the inner wall of the cavity. A cryo-medium is introduced into the ablation sealed space to cryoablate the inner wall of the cavity. This provides a usable treatment option for patients with type 2 diabetes, obesity or other cavity lesions. At the same time, it has the advantages of minimal trauma, less patient pain and low surgical risk.

[0004] The specific technical solution adopted by this invention is as follows:

[0005] A cryoablation catheter includes an inner catheter and an outer catheter, wherein the outer catheter is coaxially sleeved outside the inner catheter, and the inner catheter is configured with a multi-lumen structure. It also includes:

[0006] Multiple occlusion components, all of which are disposed on the outside of the internal catheter;

[0007] In the initial state, multiple occlusion components and the inner catheter are located inside the outer catheter. In the working state, multiple occlusion components and the intestinal wall together form an ablation sealed space. The occlusion components are configured to limit the range of action of the freezing medium when the ablation device inputs cooling medium into the ablation sealed space.

[0008] In a preferred embodiment, the outer side of the inner catheter is provided with a plurality of first media delivery holes, and the ablation sealed space and at least one cavity inside the inner catheter are interconnected through the first media delivery holes.

[0009] In a preferred embodiment, the outer side of the inner catheter is provided with multiple negative pressure through holes, and the ablation sealed space and at least one cavity inside the inner catheter are interconnected through the negative pressure through holes.

[0010] In a preferred embodiment, the occlusion assembly includes a plurality of support frames and an occlusion membrane. The plurality of support frames are arranged in a ring array on the outside of the inner catheter, and adjacent support frames do not contact each other. The occlusion membrane is fixed to the outside of the plurality of support frames, and the occlusion membrane and the inner catheter are fixedly connected.

[0011] In a preferred embodiment, the sealing membrane is made of one of the following materials: polyurethane or silicone.

[0012] In a preferred embodiment, the sealing membrane has multiple clearance openings on its outer side and between two adjacent support frames.

[0013] In a preferred embodiment, the occlusion assembly includes a positioning ring, multiple support rods, and an occlusion airbag. The positioning ring is sleeved on the outside of the inner conduit, and the multiple support rods are all fixed to the outside of the positioning ring, and the multiple support rods are arranged in a circular array on the outside of the positioning ring. The occlusion airbag is disposed between the inner conduit and the positioning ring, and the occlusion airbag and the inner conduit, as well as the occlusion airbag and the positioning ring, are fixedly connected. In the initial state, the support rods are in the form of straight segments, and in the working state, the support rods undergo elastic deformation.

[0014] In a preferred embodiment, a second medium delivery hole is provided on the outer side of the inner catheter, and clearance through holes are provided on both the positioning ring and the occlusion airbag. The occlusion airbag and at least one cavity inside the inner catheter are interconnected through the second medium delivery hole.

[0015] In a preferred embodiment, the sealing airbag is made of polytetrafluoroethylene.

[0016] In a preferred embodiment, the freezing medium may be one of the following substances: gaseous CO2, gaseous N2, liquid nitrogen, or liquid CO2.

[0017] A cryoablation system includes a cryoablation catheter and an ablation device as described in any one of the above claims, wherein the ablation device includes a control module, a display module, an input module, a working fluid module, a constant pressure module, a negative pressure module, and an impedance testing module;

[0018] The control module can receive, process relevant data, and send corresponding instructions;

[0019] The display module can display relevant data and information;

[0020] The input module can input relevant parameters and commands;

[0021] The working fluid module can deliver or extract the working fluid into or from the cryoablation catheter, and the working fluid includes a cryogenic medium and a gaseous medium.

[0022] The constant pressure module can regulate the flow rate of the refrigerant and the gaseous medium;

[0023] The negative pressure module can regulate the pressure inside the ablation sealed space and / or the sealing module;

[0024] The impedance testing module can test the impedance value of the support frame.

[0025] The technical effects achieved by this invention are as follows:

[0026] This invention involves delivering the inner and outer catheters to the target location within the duodenal cavity. An ablation-sealed space is formed by an extended sealing component that works in conjunction with the cavity wall. A cryo-medium is then introduced into this ablation-sealed space, and the cavity wall is cryoablated using the cryo-medium. This process is repeated in multiple segments until the entire duodenal cavity tissue is ablated. This provides a viable treatment option for patients with type 2 diabetes, obesity, or other lesions of natural body cavities who do not respond well to traditional drug treatments or cannot undergo traditional surgery. Furthermore, the minimally invasive technique used in this treatment offers advantages such as minimal trauma, less patient discomfort, lower surgical risk, rapid postoperative recovery, and fewer complications.

[0027] In the process of cryoablation of the duodenal wall, this invention opens a negative pressure orifice on the outside of the inner catheter and provides a stable negative pressure through the ablation device to regulate the pressure in the ablation sealed space. This allows the expanded cryo-medium to be quickly discharged through the negative pressure orifice, avoiding damage and breakage to the inner wall of the cavity due to excessive expansion of the vaporized cryo-medium, thus improving the safety performance of the device. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure in Embodiment 1 of the present invention;

[0029] Figure 2 This is an axial sectional view of the overall structure in Embodiment 1 of the present invention;

[0030] Figure 3 This is a radial sectional view of the overall structure in Embodiment 1 of the present invention;

[0031] Figure 4 This is a schematic diagram of the sealing component in Embodiment 1 of the present invention;

[0032] Figure 5 This is a schematic diagram of the sealing component in Embodiment 2 of the present invention;

[0033] Figure 6 This is a cross-sectional view of the sealing component in Embodiment 2 of the present invention;

[0034] Figure 7 This is an exploded view of the sealing component in Embodiment 2 of the present invention;

[0035] Figure 8 This is a structural block diagram of the cryoablation system in Embodiment 3 of the present invention.

[0036] The attached diagram lists the components represented by each number as follows:

[0037] 10. Inner conduit; 11. Outer conduit; 12. First medium delivery port; 13. Negative pressure through-hole; 14. Second medium delivery port;

[0038] 21. Support frame; 22. Sealing membrane; 23. Avoidance opening;

[0039] 31. Positioning ring; 32. Support rod; 33. Sealing airbag. Detailed Implementation

[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0041] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0042] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in a preferred embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments.

[0043] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include the three-dimensional spatial dimensions of length, width, and depth.

[0044] Example 1

[0045] Please see the appendix Figures 1 to 4The image shows the first embodiment of the present invention, which provides a cryoablation catheter primarily used for reconstructing the duodenal mucosa to treat type 2 diabetes and obesity. It can also be applied to the treatment of other cavity tissue diseases, such as Barrett's esophagus and biliary strictures. The catheter includes an inner catheter 10 and an outer catheter 11, with the outer catheter 11 coaxially sleeved outside the inner catheter 10. The inner catheter 10 is configured with a multi-cavity structure and further includes:

[0046] Two occlusion assemblies are provided, both of which are located on the outside of the inner catheter 10;

[0047] In the initial state, multiple occlusion components and the inner catheter 10 are located inside the outer catheter 11, and the occlusion components are in a retracted state. In the working state, the occlusion components are in an extended state, and the two occlusion components and the intestinal wall together form an ablation sealed space. The occlusion components are configured to limit the range of action of the freezing medium when the ablation device inputs the cooling medium into the ablation sealed space.

[0048] It should be noted that an ablation device and a guidewire are used in conjunction with the device. The inner catheter 10 has a cavity that is compatible with the guidewire. This cavity is referred to as the first cavity. The first cavity and the inner catheter 10 are coaxially arranged and penetrate the interior of the inner catheter 10. In addition to the first cavity, all other cavities inside the inner catheter 10 are non-penetrating cavities. The ablation device can introduce cryo-media into the ablation sealed space. The guidewire can slide inside the inner catheter 10. Under the guidance of the imaging equipment, the guidewire is delivered to the lesion location. The guidewire can guide the inner catheter 10 and the outer catheter 11 to the lesion location. The initial state is the state of the device before the cryoablation catheter enters the target location in the patient's body. The working state is the state of the device when the cryoablation catheter has reached the lesion tissue and is about to or has already begun to cryoablate the lesion tissue.

[0049] Furthermore, to describe the working process of this device in more detail, the following text uses the ablation of the duodenal mucosa as an example. Of course, this device can also be applied to the treatment of other cavity tissue diseases, such as Barrett's esophageal cancer, biliary stricture, etc., which does not constitute a specific limitation.

[0050] In this embodiment, the device is connected to an ablation instrument. Guided by imaging equipment, a guidewire is delivered into the duodenum. The inner catheter 10 and outer catheter 11 are pushed to the target location within the duodenum via the guidewire. The outer catheter 11 is kept stationary while the inner catheter 10 is pushed. The inner catheter 10 moves the occlusion assembly to the outside of the outer catheter 11. The occlusion assembly slides out from inside the outer catheter 11, changing from a retracted to an extended state, with its outer side completely adhering to the inner wall of the duodenum. The two occlusion assemblies and the intestinal wall together form an ablation-sealed space. The ablation instrument is activated, and a freezing medium is introduced into the ablation-sealed space. Upon entering the ablation-sealed space, the freezing medium causes the water within the cells of the inner wall tissue in the ablation area to rapidly condense into ice cones or ice crystals, piercing the cell walls and killing the inner wall tissue of the cavity, thereby targeting the target tissue. The duodenal mucosa is cryoablated, and then the cooling medium inside the ablation-sealed space is removed. The inner catheter 10 is pulled in the opposite direction, causing the inner catheter 10 and the sealing component to move back into the outer catheter 11. The sealing component changes from an extended form to a retracted form. This process is repeated in multiple segments until the cryoablation of the entire duodenal cavity is completed. The device can then be removed from the patient's body. Through the above procedure, cryoablation technology not only provides a new treatment option for diseases such as diabetes and obesity that can be treated by reconstructing the digestive tract mucosa, but also uses minimally invasive techniques during the treatment process, which has the advantages of less trauma, less patient pain, lower surgical risk, rapid postoperative recovery, and fewer complications. This provides a usable treatment option for patients with type 2 diabetes, obesity, or other cavity lesions who do not respond well to traditional drug treatment or cannot undergo traditional surgery.

[0051] Specifically, the freezing medium can be one of the following substances: high-pressure gaseous CO2, high-pressure gaseous N2, liquid nitrogen, liquid CO2, or other media with freezing function. According to the Joule-Thomson effect, when high-pressure gases such as high-pressure gaseous CO2 and high-pressure gaseous N2 change from a high-pressure state to a low-pressure state, the gas expands and cools down rapidly, causing the water in the cells of the inner wall tissue of the ablation area to quickly condense into ice cones or ice crystals, which pierce the cell walls and kill the tissue in the cavity, thus completing the treatment. Liquid nitrogen, liquid CO2, and other media, on the one hand, have a very low temperature and vaporize in the catheter cavity before entering the ablation area in the form of low-temperature gas, which can cause the water in the cells of the inner wall tissue of the ablation area to quickly condense into ice cones or ice crystals, which pierce the cell walls and kill the tissue in the cavity, thus completing the treatment. Preferably, in this embodiment, the freezing medium is liquid CO2.

[0052] Secondly, please refer to it again. Figures 1 to 2The inner catheter 10 has multiple first media delivery holes 12 on its outer side. The ablation sealed space and at least one cavity inside the inner catheter 10 are interconnected through the first media delivery holes 12. The cavity is referred to as the second cavity, and the second cavity is connected to the ablation device.

[0053] In this embodiment, with the above-mentioned scheme, the cryogenic medium can be delivered into the ablation sealed space through the second cavity. Under the restriction of the sealing component, the cryogenic medium comes into contact with the duodenal wall located between the sealing components. The cryogenic medium can rapidly condense the water in the cells of the inner wall tissue into ice cones or ice crystals, pierce the cell wall, thereby killing the tissue in the inner wall of the cavity, and then cryoablating the target tissue.

[0054] Secondly, please refer to it again. Figures 1 to 2 Multiple negative pressure through holes 13 are provided on the outer side of the inner catheter 10. The ablation sealed space and at least one cavity inside the inner catheter 10 are interconnected through the negative pressure through holes 13. The cavity is referred to as the third cavity. A power supply wire is provided inside at least one cavity inside the inner catheter 10. The support frame 21 is connected to the power supply wire. The cavity is referred to as the fourth cavity. The third cavity and the ablation device, the fourth cavity and the ablation device, and the power supply wire and the ablation device are all interconnected.

[0055] In this embodiment, the inner wall of the duodenum is ablated using a cryogenic medium. After the cryogenic medium vaporizes, its volume inevitably expands rapidly. By opening a negative pressure through-hole 13 on the outside of the inner catheter 10 and between the two sealing components, and connecting the negative pressure through-hole 13 to the ablation device, a stable negative pressure is provided by the ablation device, so that the expanded gas can be quickly discharged through the negative pressure through-hole 13, avoiding excessive gas volume expansion and causing damage to the cavity.

[0056] Secondly, please refer to it again. Figures 2 to 4 The sealing assembly includes multiple support frames 21 and a sealing membrane 22. The multiple support frames 21 are arranged in a ring array on the outside of the inner conduit 10, and the support frames 21 and the inner conduit 10 are fixedly connected. Adjacent support frames 21 do not contact each other. The sealing membrane 22 is fixed on the outside of the multiple support frames 21, and the sealing membrane 22 and the inner conduit 10 are fixedly connected. The sealing membrane 22 is made of one of the following materials: polyurethane, silicone, polytetrafluoroethylene or other polymer materials with good ductility. Preferably, in this example, the sealing membrane 22 is preferably made of polyurethane.

[0057] It should be noted that the support frame 21 is made of shape memory alloy. When the sealing component is located inside the outer conduit 11 and in a retracted state, the support frame 21 undergoes elastic bending. After the external force is removed (e.g., after the sealing component moves out of the outer conduit 11), the retracted sealing component changes to an extended state under the action of the support frame 21.

[0058] Furthermore, in this example, the extended occlusion assembly is frustum-shaped, and the opening directions of the two occlusion assemblies are close to each other.

[0059] In this embodiment, during cryoablation of the patient's duodenum, the inner catheter 10 and outer catheter 11 are pushed to the target position in the duodenum using a guidewire. The outer catheter 11 is kept stationary while the inner catheter 10 is pushed, causing the occlusion assembly to move outside the outer catheter 11. When the support frame 21 is removed from inside the outer catheter 11, the elastically bent support frame 21 returns to its free shape, causing the occlusion membrane 22 to unfold. This transforms the support frame 21 and occlusion membrane 22 from a retracted state to an extended state. Since the extended occlusion assembly is frustoconical in shape, the two occlusion membranes 22, in conjunction with the duodenal wall, form an ablation-sealed space. Cryotherapy medium is then introduced into this ablation-sealed space using an ablation device, thus achieving the desired ablation effect. The duodenal wall located between the two occlusion components is cryoablated. After ablation, the inner catheter 10 is pulled towards the outer catheter 11. The inner catheter 10 drives the support frame 21 and the occlusion membrane 22 to move synchronously. When the support frame 21 and the occlusion membrane 22 come into contact with the outer catheter 11, the outer catheter 11 compresses the support frame 21 and the occlusion membrane 22, causing the support frame 21 to drive the occlusion membrane 22 to bend elastically again and move into the outer catheter 11. Then, the occlusion component changes from an extended form to a retracted form, pushing the inner catheter 10 and the outer catheter 11, so that the occlusion component moves to the next target position for repeated multi-segment ablation. Finally, the cryoablation of the entire duodenal cavity tissue is completed, and the device can be removed from the patient's body.

[0060] It should be noted that the inner diameter of the outer catheter 11 is larger than the outer diameter of the inner catheter 10, so as to ensure that the support frame 21 and the sealing membrane 22, which are bent, can be completely moved into the outer catheter 11.

[0061] Please refer to it again. Figure 3 and Figure 4 As shown, multiple clearance openings 23 are provided on the outer side of the sealing membrane 22 and between two adjacent support frames 21.

[0062] Here, Figure 3 and Figure 4The size of the avoidance opening 23 is for illustrative purposes only. Its actual size is small and is only to ensure that the support frame 21 can be partially exposed (not completely wrapped by the sealing membrane 22) so that the support frame 21 can directly contact the inner wall of the duodenum. It does not constitute a specific limitation. Of course, the avoidance opening 23 will cause the ablation sealed space to not be completely sealed. After the cryo-medium is introduced into the ablation sealed space, it will overflow through the avoidance opening 23. The amount of overflow is small and will not affect the cryoablation procedure. At the same time, the inner wall of the duodenum needs to be ablated in multiple segments. Here, the amount of cryo-medium overflowing through the avoidance opening 23 is negligible.

[0063] In this embodiment, during actual production, the support frame 21 is composed of multiple round rods made of shape memory alloy. To prevent the support frame 21 from detaching from the sealing membrane 22, the edge of the sealing membrane 22 and the outermost round rod are fixedly connected by a winding manner (i.e., the edge of the sealing membrane 22 is wound around the outer side of the outermost round rod). At this time, the outer side of the sealing membrane 22 cannot directly contact the rectal wall. In order to subsequently measure the impedance value of the support frame 21 and determine whether the support frame 21 is completely attached to the duodenal wall, the avoidance notch 23 is set so that the outermost round rod can be exposed (i.e., the overlapping part of the outermost sealing membrane 22 and the avoidance notch 23 is exposed) so that it can directly contact the duodenal wall and facilitate subsequent measurement of the impedance value of the support frame 21.

[0064] Example 2

[0065] This embodiment is a further adjustment based on Embodiment 1, specifically:

[0066] Please refer to it again. Figures 5 to 7 The occlusion assembly includes a positioning ring 31, multiple support rods 32, and an occlusion airbag 33. The positioning ring 31 is sleeved on the outside of the inner catheter 10. The multiple support rods 32 are all fixed on the outside of the positioning ring 31 and are arranged in a ring array on the outside of the positioning ring 31. The occlusion airbag 33 is disposed between the inner catheter 10 and the positioning ring 31, and the occlusion airbag 33 and the inner catheter 10, as well as the occlusion airbag 33 and the positioning ring 31, are fixedly connected. In the initial state, the support rods 32 are in the form of straight segments. In the working state, the support rods 32 undergo elastic deformation. A second medium delivery hole 14 is opened on the outside of the inner catheter 10. Both the positioning ring 31 and the occlusion airbag 33 are provided with clearance through holes. At least one cavity inside the occlusion airbag 33 and the inner catheter 10 are interconnected through the second medium delivery hole 14. The cavity is referred to as the fifth cavity, and the fifth cavity is connected to the ablation device.

[0067] Furthermore, the sealing airbag 33 is made of one of the following materials: polytetrafluoroethylene or other non-stretchable polymer materials. Preferably, in this embodiment, the sealing airbag 33 is made of polytetrafluoroethylene.

[0068] It should be noted that in this example, when the device is in its initial state, the sealing component is in its retracted state, and when the device is in its working state, the sealing component is in its extended state. After the sealing airbag 33 is injected with gas and expands to its extended state, the surface area of ​​the sealing airbag 33 does not change, and its material does not expand. It simply changes from a deflated state to a full state. The process of this change can be compared with that of an inflatable castle used for children's entertainment. The extended sealing airbag 33 can completely fit the inner wall of the cavity.

[0069] Here, the first cavity, the second cavity, the third cavity, the fourth cavity, and the fifth cavity each correspond to different cavities inside the inner catheter 10, and the number of the first cavity, the second cavity, the third cavity, the fourth cavity, and the fifth cavity is at least one. The specific number can be adjusted according to actual clinical needs, and no further limitation is made here. In this example, the extended occlusion component is frustum-shaped, and the opening directions of the two occlusion components are close to each other.

[0070] In this embodiment, during cryoablation of the patient's duodenum, the inner catheter 10 and outer catheter 11 are pushed to the target position in the duodenum using a guidewire. The outer catheter 11 is kept stationary while the inner catheter 10 is pushed, causing the occlusion assembly to move outside the outer catheter 11. A gaseous medium is introduced into the device via the ablation instrument. This gaseous medium is injected into the occlusion balloon 33 through the fifth cavity and the second medium delivery port 14, causing the occlusion balloon 33 to inflate. The inflated occlusion balloon 33 changes from a retracted to an extended state. Under the action of the gaseous medium, the inflated occlusion balloon 33 autonomously adjusts the position of the eccentric inner catheter 10 until it is centered on the inner wall of the duodenum. Simultaneously, the occlusion balloon 33 causes the support rod 32 to undergo elastic deformation and limits its movement. When the outer side of the occlusion balloon 33 and the duodenum... After the duodenal wall is adhered, the two occlusion balloons 33 and the duodenal wall cooperate to form an ablation sealed space. The ablation device introduces cryo-medium into the ablation sealed space, which can perform cryoablation on the duodenal wall located between the two occlusion balloons 33. After ablation, the ablation device removes the cryo-medium inside the ablation sealed space and the gas medium inside the occlusion balloons 33, so that the occlusion balloons 33 release their restriction on the support rod 32. The elastically deformed support rod 32 will return to its original shape and drive the occlusion balloons 33 to fit tightly against the outside of the inner catheter 10. This causes the support rod 32 and the occlusion balloons 33 to change from an extended shape to a retracted shape, pushing the inner catheter 10 and the outer catheter 11, so that the occlusion component moves to the next target position for repeated multi-segment ablation. Finally, the cryoablation of the entire duodenal cavity tissue is completed, and the device can be removed from the patient's body.

[0071] Example 3

[0072] Please refer to it again. Figure 8 A cryoablation system includes a cryoablation catheter and an ablation device according to any one of the embodiments in Example 1. The ablation device and the cryoablation catheter are connected. The ablation device includes a control module, a display module, an input module, a working fluid module, a constant pressure module, a negative pressure module, and an impedance testing module.

[0073] The control module can receive and process relevant data and send corresponding instructions;

[0074] The display module can display relevant data and information;

[0075] The input module can input relevant parameters and commands;

[0076] The working fluid module can deliver or remove working fluid into or from the cryoablation catheter. The working fluid includes cryogenic media and gaseous media.

[0077] The constant pressure module can independently control the flow rate of the refrigerant and the gaseous medium.

[0078] The negative pressure module can independently regulate the pressure inside the ablation sealed space and the sealing module;

[0079] The impedance testing module is capable of testing the impedance value of the support frame 21 in Embodiment 1.

[0080] In one specific embodiment, when performing cryoablation on the duodenal wall of a patient, the cryoablation catheter is reliably connected to the ablation device. The system is powered on and performs a self-test. After the self-test passes, the impedance testing module starts working. The cryoablation catheter is placed into the target position along with the guidewire. Medical-assisted vision technology is used to determine whether the catheter has reached the target position. Then, the outer catheter 11 is withdrawn, the occlusion component is released, and the impedance testing module is used to determine whether the occlusion component is completely attached to the inner wall of the cavity. After the occlusion component and the inner wall of the cavity are completely attached and form an ablation sealed space, the working medium module is activated to input the cryo-medium into the ablation sealed space. At the same time, the negative pressure module is activated to ensure the stability of the cryoablation process. The cryo-medium is controlled by the constant pressure module. To prevent damage to the cavity by the freezing medium, after the freezing medium has been used and a certain interval has elapsed, hot steam is introduced for a period of time. The temperature of the hot steam can be adjusted as needed, with an adjustment range of 35℃ to 85℃, to facilitate the rewarming of the cavity tissue. It is even possible to perform a single thermal ablation and repeat multiple ablations. The length of a single ablation area can be set from 1cm to 10cm depending on different cavity tissues and different ablation requirements. After multiple multi-segment ablations, the ablation of the entire cavity tissue is finally completed. The equipment is powered off to prevent the negative pressure module or working medium module from continuing to work. The inner catheter 10 is pulled, so that the sealing component moves into the outer catheter 11 and changes from an extended form to a retracted form. The device is then withdrawn, completing the cryoablation of the duodenal wall.

[0081] Example 4

[0082] An impedance measurement method, applicable to any cryoablation catheter in Example 1 and any cryoablation system in Example 3, is used to determine whether the occlusion component in Example 1 is completely adhered to the inner wall of the cavity, comprising the following steps:

[0083] St1: Deliver the inner catheter 10 and the outer catheter 11 to the target position in the duodenum, push the inner catheter 10 so that the support frame 21 and the occlusion membrane 22 change from the stored form to the extended form;

[0084] St2: Within a short time slice, a high-frequency micro-voltage signal is applied to the support frame 21 in different regions in a time sequence. The impedance of each region's circuit is calculated by measuring the current in the circuit within the current time slice. When the occlusion component is in the retracted state, the support frame 21 (the region not covered by the occlusion membrane 22) is not in contact with the tissue, and the impedance of the support frame 21 is relatively high. When the occlusion component is in the extended state, if the support frame 21 (the region not covered by the occlusion membrane 22) comes into contact with the inner wall of the cavity, the impedance of the support frame 21 will decrease significantly.

[0085] It should be noted that if the preoperative preparations have been completed and the external catheter 11 has been completely withdrawn from the working area, the following judgment can be made by comparing the changes in impedance:

[0086] 1. If the impedance of all regions is significantly less than the initial impedance, then each support frame 21 and the inner wall of the cavity are in close contact with each other, indicating that everything is going smoothly and the ablation procedure can be performed successfully.

[0087] 2. If, in a blockage assembly, the impedance of several support frames 21 is significantly lower than that of other support frames 21, it indicates that the position of the inner catheter 10 has shifted, and the operator needs to make slight adjustments to the current catheter position; ensure that the impedance of all support frames 21 does not deviate significantly.

[0088] 3. If the impedance of all support frames 21 still does not decrease or the impedance of a small number of support frames 21 decreases, it is possible that the selected occlusion component is too small and cannot be used for cavity ablation.

[0089] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A cryoablation catheter, characterized in that: The system includes an inner catheter (10) and an outer catheter (11), the outer catheter (11) being coaxially sleeved outside the inner catheter (10). The inner catheter (10) is configured as a multi-lumen structure and further includes: Multiple occlusion components, all of which are disposed on the outside of the inner catheter (10); The occlusion assembly includes multiple support frames (21) and an occlusion membrane (22). The multiple support frames (21) are arranged in a ring array on the outside of the inner conduit (10), and there is no contact between two adjacent support frames (21). The occlusion membrane (22) is fixed on the outside of the multiple support frames (21), and the occlusion membrane (22) and the inner conduit (10) are fixedly connected. Multiple clearance openings (23) are provided on the outside of the occlusion membrane (22) and between two adjacent support frames (21). In the initial state, the multiple occlusion components and the inner catheter (10) are located inside the outer catheter (11). In the working state, the multiple occlusion components and the intestinal wall together form an ablation sealed space. The occlusion components are configured to limit the range of action of the freezing medium when the ablation instrument inputs the cooling medium into the ablation sealed space.

2. The cryoablation catheter according to claim 1, characterized in that: The outer side of the inner catheter (10) is provided with a plurality of first media delivery holes (12), and the ablation sealed space and at least one cavity inside the inner catheter (10) are interconnected through the first media delivery holes (12).

3. The cryoablation catheter according to claim 1, characterized in that: Multiple negative pressure through holes (13) are provided on the outer side of the inner catheter (10), and the ablation sealed space and at least one cavity inside the inner catheter (10) are interconnected through the negative pressure through holes (13).

4. The cryoablation catheter according to claim 1, characterized in that: The sealing membrane (22) is made of one of the following materials: polyurethane or silicone.

5. A cryoablation system, characterized in that: The invention includes a cryoablation catheter and ablation device according to any one of claims 1 to 4, wherein the ablation device includes a control module, a display module, an input module, a working fluid module, a constant pressure module, a negative pressure module, and an impedance testing module; The control module can receive, process relevant data, and send corresponding instructions; The display module can display relevant data and information; The input module can input relevant parameters and commands; The working fluid module can deliver or extract the working fluid into or from the cryoablation catheter, and the working fluid includes a cryogenic medium and a gaseous medium. The constant pressure module can regulate the flow rate of the refrigerant and the gaseous medium; The negative pressure module can regulate the pressure inside the ablation sealed space and / or the sealing module; The impedance test module can test the impedance value of the support frame (21).

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