A delivery mechanism, method of making a thermal blanket, and cryoablation system

Abstract

The embodiment of the present specification provides a conveying mechanism, a preparation method of a thermal insulation layer and a cryoablation system. The conveying mechanism comprises a main body part and an extension part in communication with the main body part; wherein the main body part comprises a metal pipe, the metal pipe comprises a metal pipe layer, and a first thermal insulation layer is arranged on the outer surface of the metal pipe layer. The extension part comprises a first pipe layer, a second pipe layer and a third pipe layer from inside to outside; a second thermal insulation layer is arranged on the outer surface of the first pipe layer; and the second pipe layer and the third pipe layer have a preset interval in the radial direction of the extension part. The conveying mechanism can reduce the refrigeration capacity loss of the refrigerant during the conveying process, thereby reducing the refrigeration cost and ensuring the treatment effect of cryoablation.

Description

Technical Field

[0001] This specification relates to the field of cryoablation technology, and in particular to a delivery mechanism, a method for preparing an insulation layer, and a cryoablation system. Background Technology

[0002] Cryoablation is a surgical technique that uses cryoablation to remove target tissue, often used to treat diseases such as tumors and atrial fibrillation. Cryoablation typically involves delivering a refrigerant to the target tissue using a cryoablation device. The refrigerant's evaporation absorbs heat, lowering the target tissue's temperature to destroy or eliminate its cells. However, during delivery, some refrigerant is inevitably lost due to heat exchange with the surrounding environment and the patient's blood.

[0003] Reducing refrigerant loss during delivery is of great significance for reducing refrigeration costs, improving the cooling effect of refrigerant on target tissues, and thus enhancing the therapeutic effect of cryoablation. Summary of the Invention

[0004] One embodiment of this specification provides a conveying mechanism, which includes a main body and an extension communicating with the main body; wherein, the main body includes a metal tube, the metal tube includes metal tube layers, and a first insulation layer is disposed on the outer surface of the metal tube layers; the extension includes a first tube layer, a second tube layer, and a third tube layer from the inside to the outside; a second insulation layer is disposed on the outer surface of the first tube layer; and a predetermined distance is formed between the second tube layer and the third tube layer in the radial direction of the extension.

[0005] In some embodiments, the material of the first insulation layer and / or the second insulation layer includes silica aerogel.

[0006] In some embodiments, at least a portion of the material in the second insulation layer is the same as the material in the first pipe layer.

[0007] In some embodiments, the material of the first tubular layer includes polyimide or polyetheretherketone.

[0008] In some embodiments, the material of the second and / or third tubular layers includes polyurethane or polyamide.

[0009] In some embodiments, the wall thickness of the second tube layer is 0.5 mm to 1.2 mm.

[0010] In some embodiments, the preset spacing is 1mm to 2mm.

[0011] In some embodiments, the extension further includes a smoothing layer disposed on the inner surface of the second tube layer.

[0012] In some embodiments, the material of the smooth layer includes polytetrafluoroethylene or polyethylene.

[0013] In some embodiments, the inner diameter of the first tube layer is 0.2 mm to 0.4 mm.

[0014] In some embodiments, the metal tube further includes an outer tube layer located outside the metal tube layer.

[0015] In some embodiments, the material of the outer sheath includes polyethylene terephthalate or polyethylene.

[0016] In some embodiments, the main body further includes an outer tube and an inner tube, the inner tube and the metal tube extending within the outer tube, and the outer surface of the inner tube being at least partially connected to the outer surface of the metal tube.

[0017] In some embodiments, the main body further includes a handle, the handle having a first port, one end of the metal tube being located inside the handle and connected to the first port, and the extension being able to communicate with the metal tube through the first port.

[0018] One embodiment of this specification provides a method for preparing a thermal insulation layer. This method is applicable to preparing a first thermal insulation layer and / or a second thermal insulation layer as described in the above embodiments. The material of the first thermal insulation layer and / or the second thermal insulation layer includes silica aerogel. The method includes: preparing silica aerogel powder; adding the silica aerogel powder to a corresponding solvent to form a silica aerogel solution; and coating the silica aerogel solution onto the outer surface of a metal tube layer to form the first thermal insulation layer and / or coating it onto the outer surface of the first tube layer to form the second thermal insulation layer.

[0019] In some embodiments, the method further includes: performing a surface modification treatment on the silica aerogel powder.

[0020] In some embodiments, the method further includes adding the same material as the first tube layer to the silica aerogel solution.

[0021] In some embodiments, the method further includes: after forming a second insulation layer on the outer surface of the first tube layer, performing a vacuum low-temperature drying treatment on the second insulation layer.

[0022] One embodiment of this specification provides a cryoablation system, the system including a cryoablation device, a delivery mechanism as described in the above embodiment, and a balloon; wherein, the refrigerant in the cryoablation device can be delivered to the balloon through the delivery mechanism. Attached Figure Description

[0023] This application will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0024] Figure 1 These are schematic diagrams of the conveying mechanism shown in some embodiments of this specification;

[0025] Figure 2 This is a structural schematic diagram of the main body according to some embodiments of this specification;

[0026] Figure 3 This is an axial cross-sectional view of a metal tube according to some embodiments of this specification;

[0027] Figure 4 This is a radial cross-sectional view of the main body shown in the embodiment of this specification;

[0028] Figure 5 This is a radial cross-sectional view of the extension shown in some embodiments of this specification;

[0029] Figure 6 This is an axial cross-sectional view of the extension shown in some embodiments of this specification;

[0030] Figure 7 This is a flowchart illustrating the preparation method of the thermal insulation layer according to some embodiments of this specification;

[0031] Figure 8 This is a schematic diagram of the cryoablation system according to some embodiments of this specification. Detailed Implementation

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0033] In clinical treatment, cryoablation is performed using cryoablation equipment. This equipment mainly consists of two parts: a cryoablation device and a cryoablation catheter. The cryoablation device generates, stores, and recovers the refrigerant, while the cryoablation catheter delivers the refrigerant to a balloon at its tip. The balloon contacts the target ablation site (or target tissue), and the refrigerant inside the balloon evaporates and absorbs heat (i.e., vaporizes), lowering the temperature of the target ablation site. This destroys or eliminates abnormal cells and tissues within the target ablation site, achieving cryoablation therapy. Taking the treatment of atrial fibrillation (AF) as an example, AF is a persistent arrhythmia caused by disordered spontaneous electrical activity in the pulmonary veins. Therefore, using the pulmonary veins as the target ablation site, cryoablation lowers the temperature of the pulmonary veins, destroying the abnormal electrophysiological cells and tissues within them, thereby isolating the pulmonary vein potential and treating AF.

[0034] In some embodiments, where the cryoablation device is positioned far from the patient and is longer than the cryoablation catheter, an extension cable can be installed between the cryoablation device and the cryoablation catheter. The refrigerant stored in the cryoablation device is delivered to the cryoablation catheter via the extension cable, and then transferred to the balloon located at its tip via the cryoablation catheter.

[0035] During the long-distance delivery of refrigerant from the cryoablation device to the balloon, the refrigerant exchanges heat with the surrounding environment (e.g., the atmosphere) while being transported in the extension cable, and with the external environment (e.g., the atmosphere, human blood, organs, muscle tissue, etc.) and internal environment (other liquids or gases transported within the cryoablation catheter, such as saline, contrast agents, heparin solution, or gases discharged from the balloon) of the cryoablation catheter. This causes the refrigerant to vaporize prematurely during delivery, resulting in insufficient cooling capacity of the refrigerant reaching the balloon, affecting the cooling effect and causing the temperature drop at the target ablation site to fail to meet the requirements of cryotherapy (or cryoablation therapy). In some embodiments, the cooling capacity loss during delivery can be compensated by increasing the output refrigerant capacity of the cryoablation device, ensuring that the cooling capacity of the refrigerant reaching the balloon meets the requirements for cryotherapy. However, this leads to an increase in cooling costs.

[0036] This specification provides a delivery mechanism for delivering refrigerant during cryoablation therapy. The delivery mechanism may include a main body and an extension communicating with the main body. Refrigerant stored in the cryoablation device can be delivered to the main body through the extension, and then delivered into a balloon through the main body for cryoablation therapy. The main body may include a metal tube, which may include an inner and outer metal tube layer, and a first insulation layer is disposed on the outer surface of the metal tube layer. The extension may include a first tube layer, a second tube layer, and a third tube layer, which are arranged from the inside out. A second insulation layer is disposed on the outer surface of the first tube layer, and a predetermined distance is provided between the second and third tube layers in the radial direction of the extension. The delivery mechanism provided in this specification embodiment enables long-distance delivery of refrigerant from the cryoablation device to the balloon. By providing a first insulation layer on the outer surface of the metal tube layer of the main body and a second insulation layer on the outer surface of the first tube layer of the extension, the first insulation layer effectively blocks heat transfer between the refrigerant and the external environment (e.g., atmosphere, human blood, organs, muscle tissue, etc.) and the internal environment (e.g., other liquids or gases delivered in the main body, such as saline, contrast agents, heparin solution, or gases discharged from the balloon) during delivery within the main body. The second insulation layer effectively blocks heat transfer between the refrigerant and the surrounding environment (e.g., atmosphere) during delivery within the extension, preventing the refrigerant from prematurely vaporizing before reaching the balloon. This reduces the cooling capacity loss of the refrigerant during delivery, lowers cooling costs, and ensures that the cooling capacity of the refrigerant finally reaching the balloon meets the needs of cryotherapy. In addition, by having a predetermined spacing between the second and third tube layers of the extension, a large air barrier space 125 can be formed between the second and third tube layers. This further prevents heat transfer between the refrigerant and the surrounding environment (e.g., the atmosphere) during refrigerant transport within the extension, thereby better reducing refrigerant cooling capacity loss during transport, further reducing refrigeration costs, achieving better cooling effects, and ultimately obtaining better cryogenic treatment effects. In some embodiments, the refrigerant may include liquid nitrogen, liquid nitrous oxide, etc. In some embodiments, the refrigerant may be some non-toxic refrigerants, such as R218, R124, R290, R1270, R600A, etc. Furthermore, a description of how to achieve refrigerant vaporization within the balloon can be found elsewhere in this specification and will not be described in detail here.

[0037] The conveying mechanism provided in the embodiments of this specification will now be described in detail with reference to the accompanying drawings.

[0038] Figure 1 This is a structural schematic diagram of a conveying mechanism according to some embodiments of this specification.

[0039] like Figure 1As shown, the delivery mechanism 100 may include a main body 110 and an extension 120 communicating with the main body 110. In some embodiments, one end of the main body 110 may be connected to a balloon, and the other end of the main body 110 may be connected to one end of the extension 120, which in turn may be connected to a cryoablation device. During cryoablation treatment, the refrigerant stored in the cryoablation device can be delivered from the extension 120 to the main body 110, and then from the main body 110 to the balloon. Within the balloon, the refrigerant vaporizes and absorbs heat to remove heat from the target ablation site (e.g., pulmonary vein), thereby lowering the temperature of the target ablation site and destroying abnormal cell tissue (e.g., abnormal electrophysiological cell tissue in the pulmonary vein) within the target ablation site, thus achieving cryoablation treatment. For example, it can achieve pulmonary vein potential isolation to treat atrial fibrillation.

[0040] Since the conveying mechanism 100 provided in this embodiment mainly conveys the refrigerant through the main body 110 and the extension 120, in order to describe the mechanism of the conveying mechanism 100 in detail, this specification will mainly describe the main body 110 and the extension 120 separately. The main body 110 will be described in detail below with reference to the accompanying drawings.

[0041] Figure 2 This is a schematic diagram of the main body according to some embodiments of this specification. Figure 3 This is an axial cross-sectional view of a metal tube according to some embodiments of this specification.

[0042] In some embodiments, the main body 110 may include a metal tube 111 in which refrigerant may be delivered until it reaches a balloon located at one end of the main body 110.

[0043] like Figure 3 As shown, the metal tube 111 may include a metal tube layer 1111 from the inside out, and a first insulation layer 1112 is provided on the outer surface of the metal tube layer 1111. The refrigerant can flow within the lumen of the metal tube layer 1111 until it enters the balloon and vaporizes. The first insulation layer 1112 effectively blocks heat transfer between the refrigerant within the metal tube layer 1111 and the surrounding environment of the metal tube 111 (e.g., atmosphere, human blood, organs, muscle tissue, other liquids or gases transported within the main body 110 but outside the metal tube 111, such as saline, contrast agents, heparin solution, or gases discharged from the balloon), reducing refrigerant cooling loss during transport, lowering cooling costs, and ensuring the effectiveness of cryotherapy.

[0044] In some embodiments, the refrigerant can be vaporized within the balloon by the pressure change as it enters from the metal tube layer 1111. For example, when the refrigerant enters the balloon from the higher-pressure metal tube layer 1111 (the lumen of the metal tube layer 1111) to the lower-pressure balloon, the refrigerant undergoes a phase change from liquid to gas (i.e., vaporization), thereby carrying away heat from the target ablation site and achieving cooling. In some embodiments, to ensure a greater pressure within the metal tube layer 1111 compared to the balloon (i.e., a larger pressure difference between the metal tube layer 1111 and the balloon) to allow for sufficient refrigerant vaporization, the inner diameter of the metal tube layer 1111 (i.e., the lumen diameter of the metal tube layer 1111) needs to be as small as possible compared to the balloon diameter. In some embodiments, the ratio between the inner diameter of the metal tube layer 1111 and the balloon diameter can be 0.01 to 0.08. In some embodiments, the ratio between the inner diameter of the metal tube layer 1111 and the diameter of the balloon can be 0.01 to 0.05. In some embodiments, the ratio between the inner diameter of the metal tube layer 1111 and the diameter of the balloon can be 0.03 to 0.05. In some embodiments, the inner diameter of the metal tube layer 1111 can be 0.1 mm to 0.2 mm.

[0045] In some embodiments, the metal tube layer 1111 may be made of a shape memory alloy material with high strength, good plasticity, and pressure resistance. This can prevent the metal tube layer 1111 from deforming or even being damaged due to the large pressure generated when the refrigerant is transported inside, thus affecting the stable transport of the refrigerant. In some embodiments, the material of the metal tube layer 1111 may include nickel-titanium alloy, iron-platinum alloy, or other shape memory alloy materials.

[0046] In some embodiments, the material of the first insulation layer 1112 can be a heat-insulating material (or thermal insulation material). The heat-insulating material has a low thermal conductivity (e.g., a thermal conductivity less than or equal to 0.2), enabling the first insulation layer 1112 to provide good insulation for the refrigerant within the metal tube layer 1111, effectively blocking heat transfer (or heat exchange) between the refrigerant and the surrounding environment of the metal tube 111, reducing the risk of premature vaporization of the refrigerant within the metal tube layer 1111 and resulting in cooling capacity loss. In some embodiments, the material of the first insulation layer 1112 may include polyurethane, polystyrene, composite silicate, rock wool insulation felt, rubber-plastic sponge, rock wool pipe, glass wool, etc., or combinations thereof. In some embodiments, the first insulation layer 1112 can be disposed on the outer surface of the metal tube layer 1111 in the form of a coating, film, or tube structure, to bond with and fully cover the outer surface of the metal tube layer 1111. For example, the first insulation layer 1112 can be a coating formed by applying heat-insulating material to the outer surface of the metal tube layer 1111. For example, the first insulation layer 1112 may be a pre-made film or tube structure composed of heat insulation material, which is then bonded to the outer surface of the metal tube layer 1111.

[0047] In some embodiments, the material of the first insulating layer 1112 may include silica aerogel. Silica aerogel has micropores with a pore size at the nanometer level (e.g., 2 nm to 50 nm) and a high porosity (e.g., over 90%), resulting in sufficiently long heat conduction paths and sufficiently narrow conduction pathways to effectively prevent heat conduction. Furthermore, because the micropores in silica aerogel are at the nanometer level, small enough to be smaller than the free path of air molecules, the air molecules within the micropores are approximately stationary, preventing effective air convection (or thermal convection). Simultaneously, the nanometer-sized micropores result in a near-infinite number of micropore walls, effectively reducing thermal radiation. Therefore, silica aerogel can effectively prevent heat conduction caused by the three heat transfer methods (heat conduction, heat convection, and heat radiation), and has good thermal insulation performance. It can better insulate the refrigerant in the metal tube layer 1111, thereby better blocking the heat transfer between the refrigerant and the surrounding environment of the metal tube 111, and thus greatly reducing the risk of premature vaporization of the refrigerant in the metal tube layer 1111, resulting in loss of cooling capacity. In some embodiments, the material of the first insulation layer 1112 may also include zinc oxide aerogel, alumina aerogel, carbon aerogel, polyurethane aerogel, etc., or combinations thereof. In some embodiments, silica aerogel can be coated on the outer surface of the metal tube layer 1111 in the form of a coating to form the first insulation layer 1112. In some embodiments, in order to avoid the problem of the first insulation layer 1112 easily falling off the outer surface of the metal tube layer 1111, silica aerogel can be coated on the outer surface of the metal tube layer 1111 by electrophoretic deposition, so that the first insulation layer 1112 can be tightly bonded to the outer surface of the metal tube layer 1111 and is not easy to fall off. Further description of how to prepare the silica aerogel in the first insulation layer 1112 and how to coat the prepared silica aerogel on the outer surface of the metal tube layer 1111 to form the first insulation layer 1112 can be found elsewhere in this specification and will not be repeated here.

[0048] In some embodiments, see continue to see Figure 3As shown, the metal tube 111 may further include an outer tube layer 1113 located outside the metal tube layer 1111. The outer tube layer 1113 is coaxial with the metal tube layer 1111 and has good thermal insulation properties. In some embodiments, a first thermal insulation layer 1112 can be provided on the outer surface of the metal tube layer 1111 before the outer tube layer 1113 is wrapped around it. The outer tube layer 1113 can further block heat transfer between the refrigerant inside the metal tube layer 1111 and the surrounding environment. Under the dual thermal insulation effect of the first thermal insulation layer 1112 and the outer tube layer 1113, the loss of cooling capacity of the refrigerant inside the metal tube layer 1111 during transportation is greatly reduced, which can effectively reduce refrigeration costs and ensure the effectiveness of low-temperature treatment. In some embodiments, to ensure that the outer tube layer 1113 has good thermal insulation properties, the material of the outer tube layer 1113 can be a polymer material with low thermal conductivity. In some embodiments, the material of the outer tube layer 1113 may include polyethylene terephthalate, polyethylene, polyurethane, or combinations thereof. In some embodiments, the material of the outer tube layer 1113 may also be other thermal insulation materials (e.g., composite silicates, etc.). In some embodiments, the outer tube layer 1113 may be uniformly and tightly wrapped around the outer surface (first insulation layer 1112) of the metal tube layer 1111 by heat shrinking.

[0049] In some embodiments, combined with Figure 2 and Figure 4As shown, the main body 110 may further include an outer tube 112 and an inner tube 113, with the inner tube 113 and the metal tube 111 extending within the outer tube 112. The outer tube 112 communicates with the balloon, the inner tube 113 extends through the balloon and is fixed to it, and the metal tube 111 extends into the balloon, with its end (i.e., the port from which the refrigerant exits) remaining inside the balloon. In some embodiments, the outer tube 112 can be used to discharge gas generated by the vaporization of the refrigerant within the balloon, allowing the refrigerant to continue entering the balloon for further vaporization and cryotherapy. Specifically, a gap exists between the inner wall of the outer tube 112 and the outer surfaces of the metal tube 111 and the inner tube 113, allowing the gas generated by the vaporization of the refrigerant within the balloon to exit through this gap. In some embodiments, the inner tube 113 may contain other fluids (e.g., saline, contrast agent, heparin solution, etc.) required during cryoablation therapy (e.g., treatment of atrial fibrillation). In some embodiments, the inner tube 113 can be used to deliver saline solution to expel air from the inner tube 113, preventing air from entering the vascular system of the target ablation site and causing air embolism, which could endanger the patient's life. The saline solution also cleanses the inner tube 113, keeping it clean. In some embodiments, the inner tube 113 can deliver contrast agent into the balloon. The contrast agent's imaging can be used to assess the balloon's occlusion at the pulmonary vein orifice, ensuring good contact between the balloon and the pulmonary vein orifice, thus ensuring successful cryoablation. In some embodiments, the inner tube 113 can deliver heparin solution to the target ablation site to prevent thrombosis. In some embodiments, a mapping catheter can also be placed within the inner tube 113. The mapping catheter extends within the inner tube and has a mapping electrode at its end. During atrial fibrillation treatment, the mapping electrode can be used to measure the pulmonary vein orifice potential, thereby assessing the effectiveness of cryoablation. For example, the mapping electrode can determine whether cryoablation is complete by detecting whether there are still abnormal potentials at the pulmonary vein orifice.

[0050] In some embodiments, to allow the refrigerant to vaporize at a suitable location within the balloon and generate low temperatures, the end of the metal tube 111 needs to be fixed at a specific position within the balloon. However, because the balloon undergoes morphological changes before, during, and after cryoablation, the position of the end of the metal tube 111 within the balloon can change, affecting the therapeutic effect of cryoablation. Specifically, before or after cryoablation, a low-pressure environment is required within the balloon to allow the refrigerant to vaporize. Therefore, a vacuum operation is performed on the balloon before or after cryoablation, which tightens the balloon, increases its axial length, and lengthens the distance between the end of the metal tube 111 and the inner wall of the balloon near the target ablation site. During cryoablation, the refrigerant vaporizes within the balloon, and the resulting gas fills the balloon, causing it to expand. This shortens the axial length of the balloon, and reduces the distance between the end of the metal tube 111 and the inner wall of the balloon near the target ablation site. It should be noted that the axial length of the balloon can refer to the length of the balloon along the axial direction of the metal tube 111.

[0051] In some embodiments, since the inner tube 113 is fixed to the balloon, when the balloon changes back and forth between a tightened state and an inflated state, the inner tube can change its axial length relative to the balloon, resulting in a displacement equal to the length of the change. Therefore, the metal tube 111 can be fixed to the inner tube 113, preventing relative movement between them, thus maintaining the fixed position of the end of the metal tube 111 within the balloon. Furthermore, when the axial length of the balloon changes, the balloon can cause the inner tube 113 and the metal tube 111 to produce the same axial displacement, ensuring that the relative position of the end of the metal tube 111 within the balloon does not change. In some embodiments, the fixation between the metal tube 111 and the inner tube 113 can be achieved by at least partially connecting the outer surface of the metal tube 111 (outer tube layer 1113) to the outer surface of the inner tube 113. In some embodiments, the tangential portions of the outer surface of the metal tube 111 and the outer surface of the inner tube 113 can be connected, for example, by adhesive bonding. In some embodiments, the outer surface of the metal tube 111 and the tangential portion of the outer surface of the inner tube 113 may be connected at intervals along the extension direction of the metal tube 111 (or the inner tube 113). In some embodiments, the coefficient of friction between the metal tube 111 (outer tube layer 1113) and the inner tube 113 may be increased to prevent relative movement between the metal tube 111 and the inner tube 113. In some embodiments, the outer tube layer 1113 is made of polyethylene terephthalate, polyethylene, etc., which allows for a large coefficient of friction between the outer tube layer 1113 on the metal tube 111 and the outer surface of the inner tube 113. This ensures that when the axial length of the balloon changes, causing the inner tube 113 to displace, the metal tube 111 can maintain the same displacement as the inner tube 113, thus keeping the relative position of the end of the metal tube inside the balloon constant. At the same time, it also allows for a small coefficient of friction between the outer tube layer 1113 on the metal tube 111 and the inner wall of the outer tube 112, thereby ensuring the displacement capability of the metal tube 111 within the outer tube 112 and ensuring that the balloon shape can change smoothly.

[0052] In some embodiments, see continue to see Figure 2As shown, the main body 110 may further include a handle 114, on which a first port 1141 is provided. One end of the metal tube 111 is located inside the handle 114 and connected to the first port 1141. In some embodiments, the extension 120 can communicate with the metal tube 111 through the first port. Further, the extension 120 is connected to the cryoablation device, so that the refrigerant output by the cryoablation device can be delivered sequentially through the extension 120 and the main body 110 into the balloon located at the patient's target ablation site. In some embodiments, when the distance between the cryoablation device and the patient is short, and the length of the main body 110 can meet the delivery requirements of the refrigerant from the cryoablation device to the patient, one end of the metal tube 111 can be directly connected to the cryoablation device through the first port 1141, so that the refrigerant output by the cryoablation device can be delivered only by the main body 110 into the balloon in contact with the patient's target ablation site.

[0053] In some embodiments, the handle 114 may also be provided with a second port 1142, and one end of the inner tube 113 may be located inside the handle 114 and communicate with the second port 1142. The operator can inject saline, contrast agent, heparin solution, etc., into the inner tube 113 through the second port 1142.

[0054] In some embodiments, the handle 114 is further provided with a tee connector 1143, which guides the metal tube 111 and the inner tube 113 into the outer tube 112 for extension. Specifically, the tee connector 1143 may include a first interface 11431, a second interface 11432, and a third interface 11433. The third interface 11433 communicates with the outer tube 112. The other end of the inner tube 113 passes through the first interface 11431 and the third interface 11433 into the outer tube 112 and extends therein. The other end of the metal tube 111 passes through the second structure 11432 and the third interface 11433 into the outer tube 112 and extends therein. In some embodiments, the tee connector may also include a central shaft 11434. The other end of the metal tube 111 passes through the second structure 11432, forms a loop on the central shaft 11434, and then exits through the third interface 11433 into the outer tube 112 for further extension. By forming a loop on the central axis 11434 with the metal tube 111, the metal tube 111 can move freely in its axial direction when the balloon changes back and forth between the contracted and expanded states, thus avoiding bending or damage to the metal tube 111, improving its service life, and ensuring stable delivery of refrigerant within the metal tube 111.

[0055] The extension 120 will now be described in detail with reference to the accompanying drawings.

[0056] Figure 5This is a radial cross-sectional view of the extension shown in some embodiments of this specification. Figure 6 This is an axial cross-sectional view of the extension shown in some embodiments of this specification.

[0057] Combination Figure 5 and Figure 6 As shown, the extension 120 may include a first tube layer 121, a second tube layer 122, and a third tube layer 123 from the inside out. A second insulation layer 124 may be provided on the outer surface of the first tube layer 121, and the second tube layer 122 and the third tube layer 123 have a predetermined distance D in the radial direction of the extension 120. When refrigerant is transported through the extension 120, the refrigerant flows within the cavity of the first tube layer 121 and then enters the metal tube 111 (the cavity of the metal tube layer 1111).

[0058] In some embodiments, a smaller inner diameter (i.e., the diameter of the cavity of the first tube layer 121) can maintain the refrigerant within the cavity of the first tube layer 121 in a higher pressure environment, thereby keeping the refrigerant in a liquid state and maintaining it at a lower temperature. In some embodiments, the inner diameter of the first tube layer 121 can be 0.2 mm to 0.4 mm. In some embodiments, the inner diameter of the first tube layer 121 can be 0.2 mm to 0.35 mm. In some embodiments, the inner diameter of the first tube layer 121 can be 0.2 mm to 0.3 mm.

[0059] In some embodiments, because the refrigerant has a low temperature, the pressure inside the first tube layer 121 is high. To ensure that the first tube layer 121 can stably transport the refrigerant under a certain pressure and to avoid the low temperature and high pressure affecting the structure, performance, and service life of the first tube layer 121, the material of the first tube layer 121 can be a material with good rigidity, capable of withstanding high pressure, and resistant to low temperatures. In some embodiments, the material of the first tube layer 121 may include polyimide, polyetheretherketone, or combinations thereof.

[0060] In some embodiments, by having a larger wall thickness for the second tube layer 122, the second tube layer 122 can provide some support for the first tube layer 121, thereby keeping the first tube layer 121 straight and preventing it from bending or deforming, which would affect the stable delivery of refrigerant within it. In some embodiments, to ensure that the second tube layer 122 provides good support for the first tube layer 121, the wall thickness of the second tube layer 122 can be 0.5 mm to 1.2 mm. In some embodiments, the wall thickness of the second tube layer 122 can be 0.8 mm to 1.2 mm. In some embodiments, the wall thickness of the second tube layer 122 can be 0.8 mm to 1 mm.

[0061] In some embodiments, the material of the second tube layer 122 may include polyurethane, polyamide, etc. By utilizing the relatively soft properties of polyurethane or polyamide, the second tube layer 122 can absorb the stress experienced by the extension 120 during movement, thereby reducing the deformation of the first tube layer 121 caused by stress and ensuring the stability of refrigerant delivery within the first tube layer 121.

[0062] In some embodiments, the material of the third tube layer 123 may include polyurethane, polyamide, etc., which makes the third tube layer 123 more flexible, thereby ensuring that the extension 120 has the characteristics of easy movement and change of direction, making it convenient for the operator to directly contact the third tube layer 123 to operate the extension 120, and making the extension 120 easy to move between the cryoablation device and the main body 110, so that the position and direction of the main body 110 can be adjusted according to the position of the patient's bed and the operator's operating position.

[0063] In some embodiments, the second insulation layer 124 can effectively block heat transfer between the refrigerant in the first tube layer 121 and the surrounding environment (atmosphere) of the extension 120, thereby reducing the cooling capacity loss of the refrigerant during delivery in the extension 120, reducing cooling costs, and ensuring the effectiveness of cryotherapy. In some embodiments, the material of the second insulation layer 124 can be a heat-insulating material. In some embodiments, the heat-insulating material used in the second insulation layer 124 can be the same as or different from the material of the first insulation layer 1112. In some embodiments, the second insulation layer 124 can be disposed on the outer surface of the first tube layer 121 in the form of a coating, a film, or a tube layer structure, so as to bond with and fully cover the outer surface of the first tube layer 121. In some embodiments, the material of the second insulation layer 124 may include silica aerogel or other types of aerogel. For more details on the heat-insulating material, the arrangement of the second insulation layer 124 on the outer surface of the first tube layer 121, and silica aerogel or other types of aerogel, please refer to the relevant description in the first insulation layer 1112, which will not be described in detail here.

[0064] In some embodiments, at least a portion of the material in the second insulation layer 124 may be the same as the material in the first tube layer 121. For example, if the material of the first tube layer 121 is polyimide or polyetheretherketone (PEEK), then the material of the second insulation layer 124 may also include polyimide or PEEK. In some embodiments, the material of the second insulation layer 124 may include silica aerogel and the same material as the first tube layer 121 (e.g., polyimide or PEEK). By incorporating the same material as the first tube layer 121 into the second insulation layer 124, the compatibility between the silica aerogel and the outer surface of the first tube layer 121 can be increased when the silica aerogel is applied (e.g., coated) to form the second insulation layer 124, allowing the formed second insulation layer 124 to adhere better to the outer surface of the first tube layer 121. In some embodiments, silica aerogel can be coated onto the outer surface of the first tube layer 121 by an impregnation coating method, so that the second insulation layer 124 can be tightly bonded to the outer surface of the first tube layer 121 and is not easily detached. Further description of how to prepare the silica aerogel in the second insulation layer 124 and how to coat the prepared silica aerogel onto the outer surface of the first tube layer 121 to form the second insulation layer 124 can be found elsewhere in this specification and will not be repeated here.

[0065] In some embodiments, the preset spacing D enables an air barrier space 125 to be formed between the second tube layer 122 and the third tube layer 123. This air barrier space 125 can block heat transfer between the second tube layer 122 and the third tube layer 123, further blocking heat transfer between the refrigerant in the first tube layer 121 and the surrounding environment (atmosphere) of the extension section 120, thereby better reducing the cooling capacity loss when the refrigerant is transported in the extension section 120. In addition, the air barrier space 125 can effectively block stress transmission to the first tube layer 121, protecting the first tube layer 121 from or minimally subject to stress, reducing the deformation of the first tube layer 121, and ensuring the stability of refrigerant transport within the first tube layer 121. In some embodiments, the preset spacing D can be 1mm to 2mm. In some embodiments, the preset spacing D can be 1mm to 1.8mm. In some embodiments, the preset spacing D can be 1.2mm to 1.5mm. In some embodiments, the axis of the second tube layer 122 and the axis of the third tube layer 123 may coincide, even if the second tube layer 122 is placed centrally in the cavity of the third tube layer 123. This ensures that the air barrier space 125 formed between the second tube layer 122 and the third tube layer 123 can uniformly block the heat transfer between the second tube layer 122 and the third tube layer 123 in all directions (radial), so as to have a better heat insulation effect.

[0066] In some embodiments, to ensure that the second tube layer 122 is centrally positioned within the cavity of the third tube layer 123, a connecting structure can be provided on the outer surface of the second tube layer 122. This connecting structure can be used to position and support the second tube layer 122 at a central position within the cavity of the third tube layer 123. In some embodiments, the connecting structure may include at least two protrusions located on the same cross-section of the second tube layer 122 and spaced circumferentially on its outer surface. The height of each of the at least two protrusions (i.e., the radial dimension of the protrusion on the second tube layer 122) is the same as the preset spacing D, and the included angle between adjacent protrusions is the same. This arrangement allows the at least two protrusions to support the second tube layer 122 at a central position within the cavity of the third tube layer 123. In some embodiments, the number of protrusions in the connecting structure may be 2, 3, 4, 6, etc. In some embodiments, since the second tube layer 122 has a certain length, in order to ensure that the axis of the second tube layer 122 always coincides with the axis of the third tube layer 123, the thickness of the protrusion (i.e., the dimension of the protrusion in the axial direction of the second tube layer 122) can be the same as the length of the second tube layer 122. In some embodiments, multiple connecting structures can be arranged at certain intervals along the axial direction of the second tube layer 122. Under the combined action of the multiple connecting structures, the axis of the second tube layer 122 can always coincide with the axis of the third tube layer 123. In some embodiments, an annular structure can also be used to replace the multiple protrusions in the connecting structure to support the second tube layer 122 in the middle position within the cavity of the third tube layer 123. The width of the annular structure (i.e., the dimension of the annular structure in the radial direction of the second tube layer 122) is the same as the preset spacing D.

[0067] In some embodiments, the extension 120 may further include a smooth layer (not shown), which may be disposed on the inner surface of the second tube layer 122. The smooth layer has good smoothness, ensuring that the first tube layer 121 can be smoothly assembled into the cavity of the second tube layer 122 during the assembly of the extension 120. This prevents bending of the first tube layer 121 when it enters the cavity of the second tube layer 122 due to high friction between the outer surface of the first tube layer 121 and the inner surface of the second tube layer 122. Bending would cause obstruction or blockage of refrigerant delivery within the first tube layer 121. In some embodiments, to ensure the smooth layer has smooth properties, the material of the smooth layer may include polytetrafluoroethylene, polyethylene, or combinations thereof.

[0068] The delivery mechanism 100 provided in this specification embodiment delivers refrigerant in two ways: delivery by the main body 110 and delivery by the extension 120. The main body 110, through the design of the first insulation layer 1112 and the outer tube layer 1113, reduces the loss of refrigerant capacity during delivery within the metal tube layer 1111. The extension 120, through the second insulation layer 124 and the air barrier space 125 formed between the second tube layer 122 and the third tube layer 123, reduces the loss of refrigerant capacity during delivery within the first tube layer 121. This significantly reduces the loss of refrigerant capacity throughout the entire delivery process from the cryoablation device to the balloon, reducing refrigeration costs and ensuring the effectiveness of cryotherapy.

[0069] This specification also provides a method for preparing a thermal insulation layer. This method can be applied to prepare the first thermal insulation layer 1112 and / or the second thermal insulation layer 124 in the embodiments of this specification. The material of the first thermal insulation layer 1112 and / or the second thermal insulation layer 124 is silica aerogel. Specifically, this method can be achieved by preparing a silica aerogel solution and then coating the silica aerogel solution onto the outer surfaces of the metal tube layer 1111 and the first tube layer 121 to form the first thermal insulation layer 1112 and the second thermal insulation layer 124, respectively.

[0070] Figure 7 This is a flowchart illustrating the preparation method of the thermal insulation layer according to some embodiments of this specification. For example... Figure 7 As shown, method 700 may include:

[0071] Step 710: Fabrication of silica aerogel powder. In some embodiments, silica aerogel powder can be fabricated using a sol-gel method. The sol-gel method involves the self-assembly reaction of a silicon source precursor in an alcohol / aqueous solution at a specific pH to obtain a network structure, followed by a hydrothermal reaction to obtain a porous structure, thus producing an aerogel material with a porous network structure. As an example, the fabrication process of silica aerogel powder is as follows:

[0072] (1) A certain amount of silicon source (e.g., tetraethyl orthosilicate), ethanol, and deionized water are placed in a beaker and mixed evenly to obtain a silicon source precursor solution (mass concentration 5% to 30%). The pH of the silicon source precursor solution is adjusted to a certain value (e.g., 8 to 10) by adding a pH adjuster (e.g., ammonia), and the silicon source precursor solution is reacted at a certain temperature (e.g., 30°C to 60°C) for a period of time (e.g., 18h to 36h) to obtain a gel solution with a network structure.

[0073] (2) The pH of the obtained gel solution with a network structure is adjusted to a certain value (e.g., 2-5) by adding a pH adjuster (e.g., hydrochloric acid). The gel solution with a network structure is then heated in a water bath at a certain temperature (e.g., 50℃-80℃) and subjected to hydrothermal treatment to obtain a gel solution with a porous network structure. In this case, the porous network structure silica particles are suspended in the solution in the form of nanoparticles.

[0074] (3) The gel solution with porous network structure obtained above is subjected to rotary evaporation to remove the solvent in the solution. Then a certain amount of ethanol is added, magnetically stirred and dispersed, and the ethanol is removed by filtration. The filter residue is then added to ethanol, magnetically stirred and dispersed, and the ethanol is removed by filtration. This process is repeated 3 times to fully remove the pH adjuster (e.g., ammonia, hydrochloric acid) added in the above reaction process to obtain silica aerogel.

[0075] (4) The silica aerogel obtained above is dried at a certain temperature (e.g., 50℃~100℃) for a certain period of time (e.g., 1h~5h) to obtain silica aerogel powder.

[0076] In some embodiments, after obtaining silica aerogel powder, the silica aerogel powder can be surface modified. Specifically, a certain amount of solvent (e.g., toluene) and silica aerogel powder can be added to a reaction flask, followed by a certain amount of silane coupling agent (e.g., a silica aerogel / silane coupling agent mass ratio of 2-5). The mixed solution is ultrasonically dispersed for a certain period of time, and then the solution is stirred at high speed at 60-70°C for a period of time (e.g., 18-36 hours). The solvent is removed by rotary evaporation, a certain amount of ethanol is added, and the mixture is magnetically stirred and dispersed. The ethanol is removed by filtration, and after filtering, ethanol is added again, and the mixture is magnetically stirred and dispersed. The ethanol is removed by filtration. This process is repeated 3 times. After the solvent is completely removed, the mixture is dried under vacuum at 60-80°C to obtain the solute. The solute is then ground and pulverized to obtain surface-modified silica aerogel powder. By surface modification of silica aerogel powder, coupling agents (such as silane coupling agents) are attached to the surface of the silica aerogel. This allows the silica aerogel to have a macromolecular lipophilic structure of polysiloxane at one end and a hydrophilic group containing amino groups at the other end. As a result, the silica aerogel particles naturally and regularly arrange themselves into a regular structure in the solvent due to the different compatibility of the two ends. Therefore, they can be stably arranged in the solvent, thereby improving the stability of the silica aerogel solution.

[0077] Step 720: Add silica aerogel powder to the corresponding solvent to form a silica aerogel solution.

[0078] In some embodiments, the first tube layer 121 is made of a polymer material, while the metal tube layer 1111 is made of a metal material. To ensure that the first insulation layer 1112 can adhere well to the outer surface of the metal tube layer 1111 and the second insulation layer 124 can adhere well to the outer surface of the first tube layer 121, the solvent in the silica aerogel solution used to coat the outer surface of the metal tube layer 1111 can be different from the solvent in the silica aerogel solution used to coat the outer surface of the first tube layer 121.

[0079] In some embodiments, the silica aerogel powder (e.g., surface-modified silica aerogel powder) obtained in step 710 can be added to a corresponding solvent (e.g., acetone) to form a silica aerogel solution for coating on the outer surface of the metal tube layer 1111.

[0080] In some embodiments, the silica aerogel powder obtained in step 710 can be added to a corresponding solvent (e.g., N,N-dimethylacetamide) to form a silica aerogel solution for coating the outer surface of the first tube layer 121.

[0081] In some embodiments, the same material as the first tube layer 121 (e.g., polyimide or polyetheretherketone) can be added to the silica aerogel solution used for coating the outer surface of the first tube layer 121. This increases the compatibility between the silica aerogel and the outer surface of the first tube layer 121 when the silica aerogel solution is coated onto the outer surface of the first tube layer 121 to form the second insulation layer 124, allowing the formed second insulation layer 124 to adhere better to the outer surface of the first tube layer 121. In some embodiments, since the silica aerogel powder is surface-modified, a coupling agent is attached to the surface of the silica aerogel in the silica aerogel solution. This improves the compatibility between the silica in the second insulation layer 124 and the same material as the first tube layer 121, thereby improving the uniformity of the second insulation layer 124.

[0082] Step 730: Apply silica aerogel solution to the outer surface of metal tube layer 1111 to form a first insulation layer 1112 and / or apply it to the outer surface of first tube layer 121 to form a second insulation layer 124.

[0083] In some embodiments, the silica aerogel solution obtained in step 720 can be coated onto the outer surface of the metal tube layer 1111 by electrophoretic deposition to form the first insulation layer 1112. The specific process is as follows:

[0084] (1) Inject a section (e.g., 5mm to 10mm long) of curing adhesive into the front and rear ends of the metal tube layer 1111. After UV curing, seal the inner cavity of the metal tube layer 1111 to prevent silica aerogel solution from entering the metal tube layer 1111 during the deposition process. Perform electrochemical anodizing on the metal tube layer 1111 at room temperature, then rinse the anodized metal tube layer 1111 with ultrapure water and dry it in air for later use.

[0085] (2) The anodized metal tube layer 1111 is immersed in a silica aerogel solution, with a columnar platinum mesh as the cathode, so that the negatively charged silica aerogel can be deposited on the outer surface of the anodized metal tube layer 1111. Then, the metal tube layer 1111 is repeatedly washed with ultrapure water and dried to obtain a metal tube layer 1111 coated with silica aerogel (i.e., the first insulation layer 1112). Then, the glued portions at both ends of the metal tube layer 1111 are cut off.

[0086] The first insulation layer 1112 is formed by coating a silica aerogel solution onto the outer surface of a metal tube layer 1111 using electrophoretic deposition. This method is highly efficient, low-cost, can be operated at room temperature, and allows for precise and controllable formation of a uniform coating (i.e., the first insulation layer 1112) on the outer surface of the metal tube layer 1111. Furthermore, since the metal tube layer 1111 is made of metal, electrophoretic deposition solves the problem of silica aerogel easily detaching from the metal surface, ensuring a tight bond between the first insulation layer 1112 and the outer surface of the metal tube layer 1111, preventing detachment. Meanwhile, since the silica aerogel powder has undergone surface modification, the resulting silica aerogel solution has good stability. This ensures that the silica aerogel deposited on the outer surface of the metal tube layer 1111 is evenly distributed during the electrophoretic deposition process, and ensures that the thickness of the first insulation layer 1112 is consistent. This avoids affecting the surface morphology of the outer tube layer 1113 covering the metal tube layer 1111 (first insulation layer 1112), causing unevenness on the surface of the outer tube layer 1113, which in turn affects the surface smoothness of the outer tube layer 1113. This, in turn, hinders the fixation of the metal tube 111 and the inner tube 113, as well as the relative movement of the metal tube 111 and the inner tube 113 relative to the outer tube 112.

[0087] In some embodiments, the silica aerogel solution obtained in step 720 can be coated onto the outer surface of the first tube layer 121 by an impregnation coating method to form a second insulation layer 124. The impregnation coating method is achieved by impregnating the outer surface of the first tube layer with a coating machine. The specific process is as follows:

[0088] (1) Inject a section (e.g., 5mm to 10mm long) of curing adhesive into the front and rear ends of the inner tube. After UV curing, seal the inner cavity of the inner tube to prevent the impregnation liquid from entering the first tube layer 121 during the impregnation coating process.

[0089] (2) Add silica aerogel solution to the immersion tank of the coating machine, put the first tube layer 121 into the immersion tank, and the coating machine works to coat the silica aerogel on the outer surface of the first tube layer 121 to form the second insulation layer 124.

[0090] (3) Remove the first tube layer 121 and dry the second insulation layer 124 to remove the solvent and adsorbed moisture in the second insulation layer 124. Then cut off the glued parts at both ends of the first tube layer 121.

[0091] In some embodiments, the second insulation layer 124 can be subjected to a heat-drying process to remove the solvent and adsorbed moisture from the second insulation layer 124. Specifically, heating can evaporate the solvent and moisture from the second insulation layer 124.

[0092] In some embodiments, the second insulation layer 124 can be subjected to vacuum low-temperature drying to remove solvents and adsorbed moisture. Specifically, the solvents and moisture in the second insulation layer 124 can be rapidly frozen at low temperatures. The frozen solvents and moisture are then heated under a certain vacuum level, directly sublimating into vapor and condensed into liquid by a condenser for removal. Vacuum low-temperature drying dries the second insulation layer 124 and creates a porous and loose internal structure. This results in a macroscopically loose stacked structure on top of the microporous structure of the silica aerogel within the second insulation layer 124, which is beneficial for improving its thermal insulation performance. Simultaneously, vacuum low-temperature drying avoids damaging the thermal stability of the material of the first tube layer 121, preserving the original properties of the silica aerogel and ensuring that the second insulation layer 124 is uniformly distributed on the outer surface of the first tube layer 121.

[0093] Figure 8 This is a schematic diagram of the cryoablation system according to some embodiments of this specification.

[0094] like Figure 8 As shown, the cryoablation system 800 may include a delivery mechanism 100, a cryoablation device 200, and a balloon 300. During cryoablation, the refrigerant in the cryoablation device 200 can be delivered through the delivery mechanism 100 to the balloon 300, which is in contact with the target ablation site. The refrigerant then vaporizes within the balloon 300 to remove heat from the target ablation site, thereby lowering the temperature of the target ablation site and achieving the purpose of destroying or eliminating abnormal cell tissue (e.g., abnormal electrophysiological cell tissue in pulmonary veins) in the target ablation site.

[0095] The beneficial effects that the embodiments of this specification may bring include, but are not limited to: (1) By setting a first insulation layer and an outer sleeve layer on the outer surface of the metal tube layer, the embodiments of this specification can effectively block the heat transfer between the refrigerant and the surrounding environment of the main body when the refrigerant is transported through the main body, reduce the cooling capacity loss of the refrigerant when it is transported through the main body, reduce the cooling cost, and ensure the low temperature treatment effect; (2) By setting a second insulation layer on the outer surface of the first tube layer and setting a preset gap between the second tube layer and the third tube layer to form an air barrier space, the embodiments of this specification can effectively block the heat transfer between the refrigerant and the surrounding environment of the extension section when the refrigerant is transported through the extension section, reduce the cooling capacity loss of the refrigerant when it is transported through the extension section, reduce the cooling cost, and ensure the low temperature treatment effect; (3) The embodiments of this specification In the example, the first and second insulation layers are made of silica aerogel, which has good thermal insulation properties and can effectively reduce the cooling capacity loss of the refrigerant during transportation; (4) In this embodiment, the second insulation layer is made of the same material as the first tube layer, so that the second insulation layer and the outer surface of the first tube layer are better bonded together; (5) The silica aerogel powder in this embodiment is surface modified to make the silica aerogel solution have good stability; (6) In this embodiment, when preparing the second insulation layer, the second insulation layer on the outer surface of the first tube layer is vacuum low-temperature dried, which can avoid damaging the thermal stability of the material of the first tube layer, which is beneficial to improving the thermal insulation performance of the second insulation layer and can make the second insulation layer evenly distributed on the outer surface of the first tube layer.

[0096] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects may be any one or a combination of the above, or any other possible beneficial effects.

[0097] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this specification, and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0098] Furthermore, this specification uses specific terms to describe embodiments of this application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0099] Similarly, it should be noted that, in order to simplify the description disclosed in this specification and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of embodiments of this application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of this application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of a single embodiment disclosed above.

[0100] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments of this application. Other variations may also fall within the scope of this application. Therefore, alternative configurations of the embodiments of this application are considered as examples and not limitations, and are regarded as consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this application.

Claims

1. A conveying mechanism, characterized in that, The conveying mechanism includes a main body and an extension communicating with the main body; wherein, The main body includes a metal tube, the metal tube includes a metal tube layer, and a first heat insulation layer is provided on the outer surface of the metal tube layer; The extension includes a first tube layer, a second tube layer, and a third tube layer from the inside out; a second insulation layer is provided on the outer surface of the first tube layer; and a predetermined distance is provided between the second tube layer and the third tube layer in the radial direction of the extension. A connecting structure is provided on the outer surface of the second tube layer, the connecting structure being used to position and support the second tube layer at the middle position within the cavity of the third tube layer; The connection structure includes at least two protrusions, which are located on the same cross section of the second tube layer and are spaced apart on the outer surface of the second tube layer along the circumferential direction. Alternatively, a ring structure can be used to replace the multiple protrusions in the connecting structure; The main body also includes an outer tube and an inner tube, the inner tube and the metal tube extending inside the outer tube, and the outer surface of the inner tube being at least partially connected to the outer surface of the metal tube; The refrigerant flows within the cavity of the first tube layer and then enters the metal tube.

2. The conveying mechanism according to claim 1, characterized in that, The material of the first insulation layer and / or the second insulation layer includes silica aerogel.

3. The conveying mechanism according to claim 2, characterized in that, At least a portion of the material in the second insulation layer is the same as the material in the first pipe layer.

4. The conveying mechanism according to claim 1, characterized in that, The material of the first tube layer includes polyimide or polyetheretherketone.

5. The conveying mechanism according to claim 1, characterized in that, The material of the second and / or third tubular layers includes polyurethane or polyamide.

6. The conveying mechanism according to claim 1, characterized in that, Furthermore, the wall thickness of the second tube layer is 0.5mm to 1.2mm.

7. The conveying mechanism according to claim 1, characterized in that, The preset spacing is 1mm to 2mm.

8. The conveying mechanism according to claim 1, characterized in that, The extension also includes a smoothing layer disposed on the inner surface of the second tube layer.

9. The conveying mechanism according to claim 8, characterized in that, The material of the smooth layer includes polytetrafluoroethylene or polyethylene.

10. The conveying mechanism according to claim 1, characterized in that, The inner diameter of the first tube layer is 0.2mm~0.4mm.

11. The conveying mechanism according to claim 1, characterized in that, The metal tube also includes an outer tube layer located outside the metal tube layer.

12. The conveying mechanism according to claim 11, characterized in that, The material of the outer sheath includes polyethylene terephthalate or polyethylene.

13. The conveying mechanism according to claim 1, characterized in that, The main body also includes a handle, on which a first port is provided. One end of the metal tube is located inside the handle and connected to the first port. The extension part can communicate with the metal tube through the first port.

14. A cryoablation system, characterized in that, The system includes a cryoablation device, a delivery mechanism as described in any one of claims 1-13, and a balloon; wherein the refrigerant in the cryoablation device can be delivered to the balloon via the delivery mechanism.

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