Cryoablation needle with adjustable JT slot position

Abstract

The present invention discloses a cryoablation needle with an adjustable JT slot position, comprising a vacuum wall, a JT slot and a JT slot adjustment device, wherein the vacuum wall comprises a needle bar and an inner tube, the distal end of the needle bar has a needle tip, the inner tube is drilled into the needle bar, a sandwich is formed between the inner tube and the needle bar, the distal end of the inner tube has a first predetermined distance from the distal end of the needle bar, the JT slot is drilled into the inner tube, the distal end of the JT slot is switchable between at least two adjustment positions relative to the vacuum wall, the two adjustment positions include a first adjustment position and a second adjustment position, among the regions distributed along the axial direction of the vacuum wall, the region where the sandwich is located is a vacuum insulation region, the region where the first predetermined distance is located is a target region, the first adjustment position is in the target region, and the second adjustment position is in the vacuum insulation region. The present invention significantly accelerates the cooling rate by switching the distal end of the JT slot between at least two adjustment positions.

Description

[Technical field]

[0001] The present invention relates to the technical field of cryoablation, and in particular to a cryoablation needle with an adjustable JT slot position. [Background technology]

[0002] Cryoablation is a treatment that destroys diseased tissue by low temperature and is considered to be a highly effective and minimally invasive treatment for malignant tumors. Cryoablation technology is not only easy to operate, has few complications, and has a high analgesic effect, but also allows for the safe ablation of lesions close to large blood vessels and vital organs because the boundaries of the ice ball formed for ablation are clear and easy to observe. In addition, cryoablation can take the form of multi-needle freezing, which allows for ablation of a larger area and is suitable for large lesions or lesions with irregular shapes.

[0003] During cell freezing, ice crystals are first formed outside the cells, which causes an increase in the concentration of extracellular solutes, resulting in a hypertonic environment, and intracellular water enters the outside of the cells, causing intracellular dehydration. The cells that have lost moisture become wrinkled, the cell membrane is deformed, and cause "solution damage" in a highly toxic environment. At the same time, the ice crystals formed inside the cells directly damage the cell organelles and cell membranes, causing further necrosis, which is generally called "intracellular ice damage", and intracellular ice damage directly damages the cell structure, so the destructive force on the cells is more powerful. In general, the slower the cooling rate of the cells, the higher the probability of "solution damage" occurring, and the faster the cooling rate, the easier it is to induce "intracellular ice damage". Therefore, in tumor cryoablation surgery, a faster cooling rate is generally required, which can kill the tumor more thoroughly and save a lot of treatment time.

[0004] The development of cryoablation technology has gone through three stages. The first stage is the liquid nitrogen transport freezing technology, which uses low driving pressure to deliver liquid nitrogen at -196°C to the tip of the cryoablation needle to achieve the purpose of cryoablation. The cold source in this technology relies entirely on liquid nitrogen, but the liquid nitrogen is stored in the main engine or liquid nitrogen tank, which is transported a long distance from the needle tip. During the process of transporting liquid nitrogen, the temperature of the needle tip does not reach -196°C until the entire transport pipeline reaches -196°C, so the cooling speed of liquid nitrogen freezing is the slowest of existing technologies. The second stage is the direct squeeze-freezing technology, which utilizes the principle of the Joule Thomson effect (JT), transporting room temperature ultra-high pressure gas to the JT slot (a capillary that generates the JT effect) in the cryoablation needle to perform the direct squeeze process and reduce the temperature. The cooling speed is relatively the fastest among existing technologies, but the structure of the JT slot and fin tube inside the needle tip still consumes some of the cold air, which makes the cooling time longer. In addition, the ultra-high pressure gas used is not widely used and is expensive, making it difficult to popularize this technology. The third stage is the squeeze-freezing technology with pre-cooling, which is based on the principle that general industrial gas at room temperature is pre-cooled by the related main machine, then transported to the JT slot in the cryoablation needle to perform the squeeze process and reduce the ablation temperature to a lower temperature than the pre-cooling temperature. This technology solves the problem that the gas source is expensive and rare. By combining with squeeze-freezing technology, the cooling speed is much faster than liquid nitrogen freezing technology, but compared with direct squeeze-freezing technology, the cooling speed is still slow. Summary of the Invention [Problem to be solved by the invention]

[0005] In order to address the above-mentioned problems of the prior art and solve the problem of the slow cooling rate of the prior art, the present invention proposes a cryoablation needle with an adjustable JT slot position.

[0006] In order to solve the above technical problems, the present invention is realized by the following technical solutions.

[0007] The present invention provides a cryoablation needle with an adjustable JT slot position, comprising a vacuum wall, a JT slot, and a JT slot adjustment device, wherein: the vacuum wall includes a needle bar and an inner tube; the distal end of the needle bar has a needle tip; the inner tube is inserted into the needle bar, and a sandwich is formed between the inner tube and the needle bar, and the sandwich is capable of forming a vacuum; a distal end of the inner tube has a first predetermined distance from a distal end of the needle bar along an axial direction of the vacuum wall, the distal end of the inner tube being an end of the inner tube close to the needle tip; The JT slot is drilled in the inner tube, a distal end of the JT slot is switchable between at least two adjustment positions relative to the vacuum wall, the at least two adjustment positions including a first adjustment position and a second adjustment position, the distal end of the JT slot being an end of the JT slot proximate to the needle tip; Among the regions distributed along the axial direction of the vacuum wall, the region in which the sandwich is located is a vacuum insulation region, and the region in which the first predetermined distance is located is a target region; the first adjustment position is within the target area; The second adjustment position is in the vacuum insulation region, the JT slot adjustment device is used to adjust a position of the distal end of the JT slot, thereby switching the distal end of the JT slot between the at least two adjusted positions; When the distal end of the JT slot is in the first adjustment position, the distal end of the JT slot has a second predetermined distance along the axial direction of the vacuum wall between the distal end of the JT slot and the needle tip, and the second predetermined distance at least ensures that an ice ball formed by freezing covers the needle tip, i.e., the refrigerant fluid returns from the inside of the target area and the inside of the vacuum insulation area after being discharged from the JT slot, where the refrigerant fluid exchanges heat with a material outside the entire target area while returning from the inside of the target area; When the distal end of the JT slot is in the second adjustment position, the distal end of the JT slot has a third predetermined distance along the axial direction of the vacuum wall between the distal end of the vacuum insulation region, the third predetermined distance at least ensures that the refrigerant returns directly from within the vacuum insulation region after being discharged from the JT slot, and there is only a relatively static refrigerant in the target region and no heat exchange with materials outside the target region, i.e., the refrigerant does not release any cold air in the target region during freezing. The distal end of the vacuum insulation region is the end of the vacuum insulation region near the needle tip.

[0008] Preferably, the JT slot includes a JT slot straight section and a JT slot spiral section, and the JT slot straight section and the JT slot spiral section are distributed in sequence from the distal end to the proximal end of the JT slot; the JT slot adjustment device includes a first slider and a first slider guide; the first slider guide portion is connected to the JT slot straight portion, and the first slider is fixedly connected to the first slider guide portion; the first slider, the first slider guide and the JT slot straight section are controllable to move along the axial direction, thereby switching an adjustment position of the distal end of the JT slot; Here, the position of the proximal end of the JT slot spiral portion is constant relative to the vacuum wall, the JT slot spiral portion can expand or contract as the JT slot straight portion moves along the axial direction, and the proximal end of the JT slot spiral portion is the end of the JT slot spiral portion away from the needle tip.

[0009] Preferably, the needle further comprises a first seal assembly, the first seal assembly being in sealing connection with a proximal end of the inner tube, the proximal end of the inner tube being an end of the inner tube remote from the needle tip; A dynamic seal is provided between the first seal assembly and the first slider guide.

[0010] Preferably, the first seal assembly includes a sealing device and an extension tube; a distal end of the extension tube is sealed to a proximal end of the inner tube, the distal end of the extension tube being an end of the extension tube proximal to the needle tip; The sealing device is sealedly connected to the proximal end of the extension tube and forms a dynamic seal between the sealing device and the second slider guide portion, the proximal end of the extension tube being the end of the extension tube away from the needle tip.

[0011] Preferably, the JT slot adjustment device includes a pressure tube, a second slider, and a second slider guide, a distal end of the pressure tube is connected to a proximal end of the JT slot, the distal end of the pressure tube being an end of the pressure tube close to the needle tip; The proximal end of the pressure tube is a closed structure, The second slider guide portion is provided along the axial direction, The second slider is connected to a proximal end of the pushing tube, and the second slider is slidable relative to the second slider guide portion; The second slider, the push tube and the JT slot are controllable to move synchronously along the axial direction, thereby switching an adjustment position of the distal end of the JT slot.

[0012] Preferably, the valve further includes a second seal assembly. the second seal assembly is fixedly sealed against a proximal end of the second slider guide; The second seal assembly provides a dynamic seal between the second slider guide and the push tube.

[0013] Preferably, the vacuum wall further comprises an outer tube and a gasket, wherein: the gasket is disposed between an outer wall of the distal end of the inner tube and an inner wall of the needle bar to form a sealed connection; a distal end of the outer tube is sealingly connected to a proximal end of the needle rod, a proximal end of the outer tube is sealingly connected to a proximal end of the inner tube, the distal end of the outer tube being an end of the outer tube close to the needle tip, and the proximal end of the outer tube being an end of the outer tube away from the needle tip; The outer diameter of the outer tube is larger than the outer diameter of the needle bar, and the inner diameter of the outer tube is larger than the inner diameter of the needle bar, From the distal end to the proximal end of the inner tube, the inner tube includes an inner tube front section and an inner tube rear section, in that order, an outer diameter of the inner tube rear section is larger than an outer diameter of the inner tube front section, and an inner diameter of the inner tube rear section is larger than an inner diameter of the inner tube front section, The front portion of the inner tube is drilled into the needle bar, and the rear portion of the inner tube is drilled into the outer tube.

[0014] Preferably, the device further comprises a temperature measurement line; a distal end of the temperature measuring line is a temperature measuring point, the distal end of the temperature measuring line being an end of the temperature measuring line proximal to the needle tip; The temperature measurement point is provided at the distal end of the JT slot and is used to measure the temperature at the distal end of the JT slot.

[0015] Preferably, the spring and snap member further comprises: one end of the spring is movable synchronously with the distal end of the JT slot and is also connected to the snap member, the snap member being movable into and out of a snap position; The other end of the spring is fixed to the vacuum wall; When the snap member is in the snap position, the spring is held in a deformed state by the restriction of the snap member and the distal end of the JT slot is in the second adjustment position; The deformation state is a compression state or an extension state, When the snap member is released from the snap position, the spring can generate a restoring force to return from the deformed state to a natural state, and the restoring force can drive the distal end of the JT slot to advance from the second adjustment position to the first adjustment position.

[0016] Preferably, the spring collar further comprises: When the distal end of the JT slot switches from the second adjustment position to the first adjustment position, the spring collar is used to limit the farthest distance the spring can move distally, and when the distal end of the spring is in the spring collar, the distal end of the JT slot is in the first adjustment position.

[0017] Preferably, the snap member comprises a locating pin and a C-ring, wherein: The positioning pin is provided on the C-ring, The C-ring is covered by an outer wall whose relative position with respect to the vacuum wall is constant, thereby preventing the snap member from coming off in the radial direction, When the distal end of the JT slot is in the first adjustment position, the locating pin is used to hold the spring in the deformed state.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) In the cryoablation needle with adjustable JT slot position provided by the present invention, the position of the distal end of the JT slot is adjustable, including at least two adjustable positions; by activating the freezing after the JT slot is retreated inside the vacuum insulation area, all the transport pipelines on the main machine side and the cryoablation needle side can be pre-purged (cooled); and since this pre-purge process does not consume any cold air in the target area, all the cold air is used to cool the transport pipelines, so that the cooling process of the transport pipelines is the fastest; furthermore, since no cold air is released in the target area during pre-purge, no frost or ice will occur in the target area, and the formal treatment can be directly carried out.

[0020] (2) In the cryoablation needle with adjustable JT slot position provided by the present invention, the position of the distal end of the JT slot is adjustable, including at least two adjustable positions, and the cryoablation needle after pre-purging is not only cooled in the target area of ​​the vacuum wall, but also when the JT slot is retracted inside the target area and then the freezing is activated, all the heat load is only on the target area and the tumor tissue outside it, so that the cooling speed of this freezing process is greatly accelerated.

[0021] (3) The cryoablation needle with adjustable JT slot position provided by the present invention can keep the pre-purge mode on after the tool test process is finished, and the inside of the vacuum insulation area (the distal end of the JT slot) can be kept at the lowest temperature, and no cold air is released into the target area, so that operations such as puncturing, scanning, positioning, etc. can be performed. After being punctured into the designated position, the cryoablation needle can be adjusted to the freezing mode, at which point the inside of the target area is directly and instantly cooled from normal temperature to the lowest temperature, which enables extreme and rapid cooling during the formal treatment.

[0022] (4) The cryoablation needle with adjustable JT slot position provided by the present invention has a wide range of applications and can be applied to all existing cryoablation techniques, such as liquid nitrogen transport freezing technology, direct squeeze freezing technology, and squeeze freezing technology via pre-cooling. It can be applied not only to percutaneous puncture cryoablation instruments but also to cryoablation instruments for natural orifice procedures.

[0023] Of course, any given product embodying the present invention need not necessarily achieve all of the above advantages simultaneously. [Brief description of the drawings]

[0024] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces drawings used in the description of the embodiments or the prior art. It should be understood that the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative efforts.

[0025] [Figure 1] 1A and 1B are diagrams illustrating the adjustment principle of the JT slot in a rigid cryoablation needle with an adjustable JT slot position according to one embodiment of the present invention. [Diagram 2] 1A to 1C are diagrams illustrating the adjustment principle of the JT slot in a flexible cryoablation needle with an adjustable JT slot position according to one embodiment of the present invention. [Diagram 3] 13A-13C illustrate a pre-purge mode of an adjustment scheme for interlocking the mandrel and JT slot of a rigid cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 4] FIG. 13 illustrates the freeze mode of the adjustment scheme for interlocking the mandrel and JT slot of a rigid cryoablation needle in accordance with a preferred embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram illustrating a vacuum wall of a flexible cryoablation needle according to a preferred embodiment of the present invention. [Figure 6]13A-13C illustrate a pre-purge mode of an adjustment scheme for interlocking the mandrel and JT slot of a flexible cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 7] 13A-13C illustrate the freeze mode of an adjustment scheme for interlocking the mandrel and JT slot of a flexible cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 8] FIG. 13 illustrates the pre-purge mode of the adjustment scheme for interlocking the pusher tube and JT slot of a rigid cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 9] 13A-13C show the core adjustment mechanism in pre-purge mode of the adjustment scheme interlocking the pusher tube and JT slot of a rigid cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 10] FIG. 13 illustrates the freezing mode of the adjustment scheme for interlocking the pusher tube and JT slot of a rigid cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 11] FIG. 13 illustrates the core adjustment mechanism in freeze mode of the adjustment scheme interlocking the pusher tube and JT slot of a rigid cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 12] 13A-13C illustrate a pre-purge mode of an adjustment scheme for interlocking a pusher tube and a JT slot of a flexible cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 13] FIG. 13 illustrates the freeze mode of the adjustment scheme for interlocking the pusher tube and JT slot of a flexible cryoablation needle in accordance with a preferred embodiment of the present invention. [Figure 14] 1 is a schematic diagram of a seal assembly according to a preferred embodiment of the present invention; [Figure 15] 1 is a schematic diagram of a slider according to a preferred embodiment of the present invention. [Figure 16] 1 is a schematic diagram of a snap member according to a preferred embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The technical solutions in the embodiments of the present invention will be described below in a clear and complete manner in conjunction with the drawings in the embodiments of the present invention, but it is clear that the described embodiments are only a part of the embodiments of the present invention, and are not all of them. Based on the embodiments of the present invention, all other embodiments that can be obtained by those skilled in the art without any creative efforts shall fall within the protection scope of the present invention.

[0027] In describing the present specification, it should be understood that the terms "upper", "lower", "top", "bottom", "lower", "top" and the like refer to an orientation or positional relationship based on that shown in the accompanying drawings and are intended only to facilitate and simplify the description of the present invention, and do not indicate or imply that the referenced device or element has a particular orientation or must be constructed and operated in a particular orientation, and therefore are not to be construed as limitations of the present invention.

[0028] In the description of the present specification, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying a relative importance or a number of technical features depicted. Thus, features qualified as "first" and "second" may explicitly or implicitly include one or more such features.

[0029] In the present description, "plurality" means, for example, two, three, four, etc., unless otherwise limited.

[0030] The technical solutions of the present invention are described in detail below by taking specific examples. These specific examples below can be combined with each other, and some examples do not repeat the same or similar concepts or processes.

[0031] 1 and 2 are diagrams illustrating the adjustment principle of the JT slot in a cryoablation needle with an adjustable JT slot position according to one embodiment of the present invention.

[0032] 1 and 2, the cryoablation needle with an adjustable JT slot position according to the present embodiment includes a vacuum wall 2, a JT slot 1, and a JT slot adjustment device. The vacuum wall 2 includes a needle bar 21 and an inner tube 22, and the distal end of the needle bar 21 has a needle tip 211. The inner tube 22 is drilled into the needle bar 21, and a sandwich is formed between the inner tube 22 and the needle bar 21, which can form a vacuum and can be either a permanent vacuum sandwich or a real-time vacuum sandwich, and the vacuum sandwich serves to insulate and prevent frostbite of normal tissue.

[0033] There is a first predetermined distance between the distal end of the inner tube 22 and the distal end of the needle bar (this first predetermined distance can be understood as a spacing distance along the axial direction of the vacuum wall), and the distal end of the inner tube 22 is the end of the inner tube 22 close to the needle tip 211. The JT slot 1 is drilled in the inner tube 22. Among the regions distributed along the axial direction of the vacuum wall, the region in which the vacuum sandwich is located is the vacuum insulation region 26 since the vacuum sandwich can perform the role of insulation, and the region in which the first predetermined distance is located is the target region 25.

[0034] The distal end of JT slot 1 has at least two adjustment positions, and further, the distal end of the JT slot is switchable between the at least two adjustment positions relative to the vacuum wall (e.g., by movement along the axial direction of the vacuum wall), the at least two adjustment positions including a first adjustment position and a second adjustment position, and the distal end of JT slot 1 is the end close to needle tip 211 of JT slot 1, where when the first adjustment position is in the target area, it may be understood to be in a freezing mode, as shown in the dashed portion of FIG. 1, and when the second adjustment position is in the vacuum insulation area, it may be understood to be in a pre-purge mode, as shown in the solid portion of FIG. 1.

[0035] The JT slot adjustment device is used to adjust the distal end of the JT slot to switch between the at least two adjustment positions, and specifically, can adjust the distal end of the JT slot to switch between at least two adjustment positions according to an external operation. Furthermore, any device that can realize this switching adjustment function may be used without departing from the description of the present solution.

[0036] When the distal end of the JT slot is in the first adjustment position, the distal end of the JT slot has a second predetermined distance between it and the needle tip, which at least ensures that the ice ball formed by freezing covers the needle tip, i.e., that the refrigerant fluid returns from within the target area and within the vacuum insulation area after being expelled from the JT slot, where the refrigerant fluid exchanges heat with materials outside the entire target area while returning from within the target area.

[0037] When the distal end of the JT slot 1 is in the second adjustment position, the distal end of the JT slot 1 has a third predetermined distance with the distal end of the vacuum insulation region, which at least ensures that the refrigerant fluid returns directly from the vacuum insulation region after being discharged from the JT slot, and there is only a relatively static refrigerant in the target region and no heat exchange with materials outside the target region, i.e., the refrigerant does not release any amount of cold in the target region during freezing. The distal end of the vacuum insulation region is the end of the vacuum insulation region near the needle tip.

[0038] The first predetermined distance, the second predetermined distance, and the third predetermined distance here can be understood to be interval distances along the axial direction of the vacuum wall 2. Furthermore, all axial directions described below can be understood as the axial direction of the vacuum wall 2.

[0039] In one embodiment, the vacuum wall is a hard material vacuum wall applicable to a percutaneous puncture cryoablation instrument, with the needle tip 211 being in the form of a tip, as shown in FIG.

[0040] In one embodiment, the vacuum wall is a flexible material vacuum wall applicable to transorificial ablation instruments, and the needle tip 211 is in the form of a circular arc, as shown in Fig. 2. Preferably, the needle bar 21 and the inner tube 22 can be soft non-metallic material or freely bendable metallic material, such as PTFE or PTFE braided tube or stainless steel bellows.

[0041] In one embodiment, the use process of the cryoablation needle with the above-mentioned JT slot position adjustable is as follows: Before the treatment, take out the cryoablation needle in the pre-purge mode, interconnect with the main machine, insert the needle bar 21 (at least the target area 25) of the cryoablation needle into the saline solution, and start the tool test function. In the tool test, the rewarming stage is first performed, and if the temperature of the needle tip rises to a predetermined temperature within a certain time, the rewarming function is proven to be normal. Immediately after that, the program automatically performs the freezing stage, and if the temperature of the needle tip drops to a predetermined temperature within a certain time, the freezing function is proven to be normal. At this time, the time for keeping the needle tip at the lowest temperature can be appropriately extended to fully pre-purge, and then the tool test is automatically stopped. In the freezing stage, it can be observed whether there is frost on the vacuum insulation area 26, and if there is no frost, the insulation function is proven to be normal, and if there is no leakage at the needle tip immersed in saline solution during the entire stage, it is proven that the airtightness is normal. At the end of the tool test, both the main machine and the transport pipe of the cryoablation needle complete pre-purge (cooling). Immediately after that, the freezing function may be turned on first (or the separately set pre-purge function may be turned on), and the freezing at this stage may be performed at a low operating pressure or may be ventilated intermittently, thus saving gas usage while maintaining the temperature at the distal end of the JT slot at the lowest temperature. Next, with the freezing function turned on, the image-guided percutaneous puncture may be performed, and the needle tip may reach the desired tumor location. In this case, the movement of the JT slot to the distal end may be adjusted, stopped at the first adjustment position, and switched to the freezing mode. Since the entire transport duct is in a low temperature state, the cooling heat load of the cryoablation needle is only on the target region 25 and the tumor tissue outside it, and therefore, even if the freezing mode is switched on, the temperature at the distal end of the JT slot may be maintained at the lowest temperature, but the outer wall of the target region 25 may instantly drop from normal temperature to -100°C or lower.In this way, the procedure time for ablating a tumor of the same size is shortened, or a larger ablation range (ice ball) is generated within the same time, and the tumor tissue is cooled more rapidly, so the probability of intracellular ice damage to tumor cells is greatly increased, and subsequently the cryo-damage of tumor cells is more thorough and the ablation effect is better.

[0042] In a preferred embodiment, referring to Figures 3, 4, 6, and 7, the distal end position of the JT slot is adjusted by an adjustment means that moves the mandrel and the JT slot spiral portion in conjunction with each other. Specifically, from the distal end to the proximal end of the JT slot, the JT slot includes a JT slot straight portion 11 and a JT slot spiral portion 12, in that order, where the JT slot straight portion 11 and the JT slot spiral portion 12 may be of an integral structure or a split connection structure, and may be made of different materials (e.g., the JT slot straight portion 11 is stainless steel, and the JT slot spiral portion 12 is nickel-titanium alloy) or the same material (e.g., stainless steel).

[0043] In one embodiment, the JT slot adjustment device may include a mandrel 3 and a slider 8, where the distal end of the mandrel 3 is connected to the proximal end of the JT slot straight section 11, the distal end of the mandrel 3 is the end closer to the needle tip 211 of the mandrel 3, the proximal end of the JT slot straight section 11 is the end away from the needle tip 211 of the JT slot straight section 11, the proximal end of the mandrel 3 is connected to the slider 8, and the proximal end of the mandrel 3 is the end away from the needle tip 211 of the mandrel 3. When adjusting the distal end position of the JT slot, the slider 8 is used to slide the mandrel 3 axially and further drive the JT slot straight section to slide by sliding in the axial direction, and thus the slider 8, the mandrel 3 and the JT slot straight section 11 can be controlled to move synchronously along the axial direction, and further, the distal end of the JT slot straight section can be switched between at least two adjustment positions, in which case the JT slot spiral section 12 follows the sliding of the JT slot straight section 11 by expanding or compressing the JT slot spiral section 12 without changing the position of its proximal end (which can be understood to be constant with respect to the vacuum wall), i.e., the JT slot spiral section can expand or compress with the movement of the JT slot straight section 11 along the axial direction, and the proximal end of the JT slot spiral section 12 is the end portion away from the needle tip 211 of the JT slot spiral section 12.

[0044] In the above embodiment, the mandrel 3 is the first slider guide, and in this embodiment, the first slider guide is connected to the member to be adjusted (the straight portion of the JT slot), and the slider is connected to the first slider guide. In another embodiment, the slider 8 may be directly connected to the member to be adjusted (the straight portion of the JT slot), and the slider is provided on the outer or inner wall of the first slider guide, the slider 8 is slidably connected to the first slider guide, and the first slider guide is provided along the axial direction of the vacuum wall and is used to guide the movement of the slider 8 along the axial direction.

[0045] Here, Figures 3 and 6 are diagrams showing the pre-purge mode with the distal end of the JT slot in the second adjustment position, and Figures 4 and 7 are diagrams showing the freeze mode with the distal end of the JT slot in the first adjustment position.

[0046] In another embodiment, the adjustment of the distal end position of the JT slot may be achieved by the following structure: a separate elastic member is provided at the proximal end of the JT slot, in which case the distal end of the mandrel is connected to the proximal end of the JT slot, and the rest of the structure refers to the above embodiment and will not be repeated here.

[0047] In one embodiment, based on the embodiment of adjusting the mandrel and the JT slot helix in cooperation with each other as described above, a seal assembly 5 is further included to prevent gas leakage inside the vacuum wall 2 during adjustment of the distal end position of the JT slot, as shown in Figs. 2-3. The seal assembly 5 is provided at the proximal end of the inner tube 22 and provides a dynamic seal with the JT slot adjustment device.

[0048] Further, the seal assembly 5 includes a seal ring 51, a seal groove 52, and a seal pressing member 53. Here, the distal end of the seal groove 52 is sealingly connected to the proximal end of the inner tube 22. The seal ring 51 is placed in the seal groove 52, and the seal pressing member 53 is screwed into the seal groove 52 along the axial direction, so that the seal ring 51 is fixed between the seal groove 52 and the seal pressing member 53, and the mandrel 3 is inserted into the seal ring 51 and the seal pressing member 53, so that the seal ring 51 is radially pressed between the mandrel 3 and the seal groove 52 to cause deformation and form a dynamic seal. Optionally, the seal ring 51 may be a rubber seal ring such as a nitrile O-ring, or a Variseal ring of low-temperature resistant fluorine-based polymer + metal spring.

[0049] 14, in a preferred embodiment, the seal assembly 5 further includes an extension tube 54. Here, the extension tube 54, together with the intake tube 6 and the return tube 7, is inserted into the proximal end of the inner tube 2 and sealed, and the distal end of the seal groove 52 is sealed to the proximal end of the extension tube 54. The manner of connection between the seal ring 51, the seal groove 52, and the seal assembly 53 refers to the description of the above embodiment and will not be repeated here. The provision of the extension tube 54 contributes to keeping the seal ring 51 at a certain distance from the proximal end of the inner tube, the intake tube 6, and the return tube 7 on the low temperature side, thereby preventing poor sealing at low temperatures.

[0050] In a preferred embodiment, referring to Figs. 8-13, the adjustment of the distal end position of the JT slot employs an adjustment means for interlocking the push tube and the JT slot. Specifically, the JT slot adjustment device includes a push tube 17 and a slider 8. Here, the proximal end of the push tube 17 is a closed structure (e.g., a closed round tube), the proximal end of the push tube 17 is connected to the slider 8, and the proximal end of the push tube 17 is an end away from the needle tip 211 of the push tube 17. The distal end of the push tube 17 is connected to the proximal end of the JT slot 1, and the distal end of the push tube 17 is an end close to the needle tip 211 of the push tube 17. When adjusting the distal end position of the JT slot, the slider 8 is used to slide axially to slide the pushing tube 17 axially and further drive the JT slot 1 to slide, thereby enabling switching between at least two adjustment positions of the distal end of the JT slot. Figures 8 and 12 are diagrams showing a pre-purge mode in which the distal end of the JT slot 1 is in a second adjustment position, Figure 9 is a diagram showing the core adjustment mechanism in the mode, Figures 10 and 13 are diagrams showing a freezing mode in which the distal end of the JT slot 1 is in a first adjustment position, and Figure 11 is a diagram showing the core adjustment mechanism in the mode.

[0051] In a preferred embodiment, referring to Figs. 3, 4, 8, 10, the fin tube 4 is further included to improve the heat dissipation function, and the fin tube 4 is provided on the outer wall of the mandrel 3. Further referring to Figs. 9, 11, 12, 13, the intake air is introduced from the inside of the fin tube 4 or the inside of the intake pipe 6 into the inside of the JT slot 1 through the branched three-way pipe 15. The branched three-way pipe 15 includes a central orifice 151 and an intake passage 153, and the three-way pipes are both ends of the central orifice 151 and the intake passage 153, respectively. The distal end of the central orifice 151 of the branched three-way pipe 15 forms a dynamic seal with the JT slot 1, or forms a dynamic seal with the JT slot 1 by a seal pipe 18 inserted into the distal end of the central orifice 151.

[0052] 9 and 11, in one embodiment, from the distal end to the proximal end of the seal tube 18, the seal tube 18 includes, in order, a seal tube guide portion 181, a seal tube sealing portion 182, and a seal tube connection portion 183. The seal tube 18 is provided between the JT slot 1 and the vacuum wall 2, and the seal tube connection portion is inserted into the distal end of the central orifice 151 and fixedly sealed. It further includes a seal gasket 19, which is provided between the seal tube sealing portion 182 and the JT slot 1, and presses the seal tube sealing portion 182 radially to realize a low-temperature resistant dynamic seal. There is a sufficient gap for ventilation between the outer wall of the JT slot 1 and the inner wall of the central orifice 151 and the inner wall of the seal tube connection portion 183. Preferably, the seal gasket 19 adopts a PTFE tube.

[0053] 3, 4, 8 and 10, in a preferred embodiment, the vacuum wall 2 further includes an outer tube 23. A distal end of the outer tube 23 is sealingly connected to a proximal end of the needle bar 21, and a proximal end of the outer tube 23 is sealingly connected to a proximal end of the inner tube 22.

[0054] In a preferred embodiment, in order to expand the internal volume of the proximal end of the inner tube, for example, the fin tube 4 may be pushed into the proximal end of the inner tube, or more other components may be accommodated, and therefore the internal volume of the proximal end of the inner tube needs to be expanded, and furthermore, the internal volume of the proximal end of the vacuum wall needs to be expanded. The outer diameter of the outer tube 23 is larger than the outer diameter of the needle bar 21, the inner diameter of the outer tube 23 is larger than the inner diameter of the needle bar 21, the distal end of the outer tube 23 is the end close to the needle tip 211 of the outer tube 23, and the proximal end of the outer tube 23 is the end away from the needle tip 211 of the outer tube 23. Furthermore, from the distal end to the proximal end of the inner tube 22, the inner tube 22 includes an inner tube front section 221 and an inner tube rear section 222 in this order, the outer diameter of the inner tube rear section 222 is larger than the outer diameter of the inner tube front section 221, and the inner diameter of the inner tube rear section 222 is larger than the inner diameter of the inner tube front section 221. 3, 4, 8 and 10, the front section 221 of the inner tube is located inside the needle bar 21, and the rear section 222 of the inner tube is located inside the outer tube .

[0055] 3, 4, 8 and 10, in a preferred embodiment, the vacuum wall 2 further includes a gasket 24, where the gasket 24 is disposed between the outer wall of the distal end of the inner tube 22 and the inner wall of the needle bar 21 to form a sealed connection.

[0056] 5, in a preferred embodiment, the vacuum wall of the flexible cryoablation needle may further include a vacuum three-way tube 28, a vacuum connection tube 291, a vacuum hose 292 and a return air connection tube 293. Here, the proximal end of the inner tube 22 is hermetically connected to the distal end of the return air connection tube 27, the proximal end of the outer tube 23 is hermetically connected to the three-way tube connection part 281, the proximal end of the vacuum three-way tube 28 is hermetically connected to the return air connection tube 27, the distal end of the vacuum connection tube 291 is inserted into the three-way tube bypass 282, and the vacuum hose 292 is inserted into the vacuum connection tube 291, and the proximal end of the vacuum hose 292 is evacuated to maintain the gap between the inner tube 22 and the outer tube 23 in a vacuum state, which can prevent frostbite on the wall of a normal natural orifice.

[0057] In one embodiment, referring to Figures 6, 7, 12 and 13, the device further includes a shunt tube 294 for sealing gaps between the intake pipe 6, the return pipe 7 and the mandrel 3, and the intake pipe 6, the return pipe 7 and the mandrel 3 are inserted into and sealed at the proximal end of the shunt tube 294.

[0058] In a preferred embodiment, based on the embodiment of adjusting the pushing tube and the JT slot in conjunction with each other, referring to Figs. 4-7, the pushing tube 17 includes a pushing tube thin section 171 and a pushing tube thick section 172 from the distal end to the proximal end of the pushing tube 17. The distal end of the pushing tube thin section 171 is fixed to the proximal end of the JT slot 1, the pushing tube thin section 171 is provided with at least one intake slot 174 for inserting the intake tube 6 of the JT slot 1, there is a sufficient gap for ventilation between the outer wall of the pushing tube thin section 171 and the inner wall of the mandrel 3, and there is a small gap between the outer wall of the pushing tube thick section 172 and the inner wall of the mandrel 3 to allow the two to move relatively. The pushing tube thick section 171 may be a solid round bar or a round tube with at least the proximal end closed.

[0059] In a preferred embodiment, based on the embodiment of adjusting the push tube and JT slot in conjunction with each other described above, a seal assembly 5 is further included to prevent gas leakage inside the vacuum wall 2 during adjustment of the distal end position of the JT slot, see Figs. 4-7. The seal assembly 5 is fixedly sealed to the proximal end of the mandrel 3 and forms a dynamic seal with the push tube 17.

[0060] Further, the seal assembly 5 includes a seal ring 51, a seal groove 52, and a seal pressing member 53. Here, the distal end of the seal groove 52 is sealingly connected to the proximal end of the mandrel 3. The seal ring 51 is placed in the seal groove 52, and the seal pressing member 53 is screwed into the seal groove 52 along the axial direction, so that the seal ring 51 is fixed between the seal groove 52 and the seal pressing member 53, and the mandrel 3 is inserted into the seal ring 51 and the seal pressing member 53, so that the seal ring 51 is radially pressed between the mandrel 3 and the seal groove 52 to cause deformation and form a dynamic seal. Optionally, the seal ring 51 may be a rubber seal ring, such as a nitrile O-ring, or a Variseal ring of low-temperature resistant PTFE + metal spring.

[0061] In a preferred embodiment, in order to better detect the freezing effect of the cryoablation needle, see Figs. 3, 4, 6, 7, further includes a temperature measurement line 14, the distal end of which is a temperature measurement point 141, and the distal end of the temperature measurement line 14 is the end close to the needle tip 211 of the temperature measurement line 14. The temperature measurement point 141 is provided at the distal end of the JT slot 1 and is used to measure the temperature of the distal end of the JT slot 1. When the distal end of the JT slot 1 is located in the target area, the temperature measurement point 141 is used to monitor the temperature of the tumor center during cryo-rewarming, and when the distal end of the JT slot 1 is located in the vacuum insulation area, the temperature measurement point 141 is used during pre-purge to indicate whether pre-purge is performed properly or not. The temperature measurement line 14 is led from the inside of the mandrel 3 or the pressing tube 17 to the outside along the outside of the JT slot 1, and the inside of the mandrel 3 or the pressing tube 17 is sealed by filling with adhesive. Preferably, the heating line is further included, and the heating line is positioned and arranged in a manner consistent with the temperature measurement line and is used to realize the heating function. Preferably, the temperature measurement line and / or the heating line employs a T-type enameled thermocouple wire.

[0062] In one embodiment, as shown in Figures 3, 4, 6, 7, 8, 10, 12, 13, the adjustment of the distal end position of the JT slot can be achieved by manual back and forth adjustment or pre-spring 120. The spring 120 is used to hold the distal end position of the JT slot, and when the spring is in a natural state, the distal end of the JT slot is in a first adjustment position (freezing mode), as shown in Figures 4, 7, 10, 13, and when the spring 120 is in a compressed or extended state, the distal end of the JT slot is in a second adjustment position (pre-purge mode), as shown in Figures 3, 6, 8, 12. It further includes a snap member 10, and when the distal end of the JT slot is in the first adjustment position, as shown in Figures 3, 6, 8, 12, the snap member 10 is used to hold the spring 120 in a compressed or extended state, and when it is necessary to switch to the second adjustment position, it is only necessary to pull out the snap member 10.

[0063] As shown in Figures 3, 6 and 12, the spring is in a compressed state, one end (distal end) of the spring is connected to the slider 8 and the snap member 10, the other end (proximal end) of the spring is in a fixed position relative to the vacuum wall, and the snap member 10 is engaged in the first position to hold the spring in a compressed state, and at this time, the distal end of the JT slot is in the second adjustment position. When it is necessary to adjust to the first adjustment position, refer to Figures 4, 7 and 13, and when the snap member is pulled out from the first position, the elastic force of the spring drives the slider 8 to slide the JT slot along the axial direction toward the distal end position and stop at the first adjustment position, and at this time, the spring is in its natural state.

[0064] As shown in Fig. 8, the spring is in an extended state, one end (proximal end) of the spring is connected to the slider 8 and the snap member 10, the other end (distal end) of the spring is in a fixed position relative to the vacuum wall, and the snap member 10 is engaged in the first position to hold the spring in an extended state, with the distal end of the JT slot in the second adjustment position. When it is necessary to adjust to the first adjustment position, refer to Fig. 10, and pull out the snap member from the first position, and the elastic force of the spring drives the slider 8 to slide the JT slot along the axial direction toward the distal end position and stop at the first adjustment position, with the spring in its natural state.

[0065] In a preferred embodiment, in order to more accurately position the distal end of the JT slot in the natural position of the spring 120, i.e., the first adjustment position, a spring collar 27 is further provided, see Figures 8 and 10. The spring collar 27 is used to prevent the spring 120 from moving further distally, and when the distal end of the spring 120 is located at the spring collar 27, the distal end of the JT slot 1 is in the first adjustment position.

[0066] In one embodiment, as shown in FIG. 3, the snap member 10 includes a positioning pin 102. In this embodiment, the snap member 10 further includes a lever 9, which is provided at the proximal end of the cryoablation needle, making it easy to grasp. The lever 9 is provided with a lever positioning groove 91, and the slider 8 is provided with a slider positioning groove 82. When the distal end of the JT slot is in the first adjustment position, the positioning pin 102 is inserted into the lever positioning groove 91 and the slider positioning groove 82 at the same time, so that the relative position of the slider 8 to the lever 9 is constant, i.e., it is kept in the current pre-purge mode, and in this embodiment, the spring 120 is in a compressed state at this time. When it is necessary to switch to the cryoablation mode, the positioning pin 102 can be simply pulled out from the lever positioning groove 91 and the slider positioning groove 82.

[0067] In one embodiment, in order to encase components such as the intake pipe, return pipe, etc., and to make the cryoablation needle look neater and easier to operate, an outer sleeve 13 is further provided on the outer wall of the lever 9, see Figures 3, 4, 6, 7, 8, 10, 12, and 13.

[0068] 6, 7, 12 and 13, the distal end of the lever of the flexible cryoablation needle is further provided with a bend guard 92. The bend guard 92 can be provided on the outer wall of the outer tube 23 to protect the contact point between the vacuum wall and the distal end of the lever from bending.

[0069] 16, in order to facilitate the fixing and insertion / removal adjustment of the snap member, the snap member 10 further includes a gripping portion 101 and a C-shaped ring 103. Here, the gripping portion 101 and the positioning pin 102 are provided on the C-shaped ring 103, and the C-shaped ring 103 is covered by the outer wall of the lever 9, thereby preventing the snap member from coming off in the radial direction.

[0070] In another embodiment, when the lever 9 is not included, the C-shaped ring 103 can be prevented from coming off in the radial direction by simply being covered by an outer wall whose relative position with respect to the vacuum wall is constant.

[0071] In another embodiment, the spring may be in an extended state when the distal end of the JT slot is in a first adjustment position, and in a relaxed state when the distal end of the JT slot is in a second adjustment position.

[0072] In a preferred embodiment, referring to FIG. 15, the slider 8 further includes a guide tube 81, a slider positioning groove 82, a central fixing hole 83, and a guide hole 84 for the intake and return air pipes. Here, the guide tube 81 is provided along the axial direction of the vacuum wall. The slider positioning groove 82 is opened on the outer wall of the guide tube 81 and is used to insert the positioning pin of the snap member 10 in the above-mentioned embodiment, and in another embodiment, this part may be omitted when the adjustment spring is not used. The central fixing hole 83 and the guide hole 84 for the intake and return air pipes are provided in the guide tube 81, the proximal end of the mandrel 3 is inserted into the central fixing hole 83, and the guide hole 84 for the intake and return air pipes is used to pass the intake air pipe 6 and the return air pipe 7 through.

[0073] In the above embodiment, the guide tube 81 is the second slider and the second slider guide, and the guide tube 81 can move along the axial direction. In another embodiment, the slider 8 may be guided by a mandrel provided in the axial direction of the vacuum wall, and the slider 8 may be provided on the outer wall of the mandrel and guided to slide along the axial direction by sliding along the mandrel. In another embodiment, the second slider guide may be connected to the adjusted part (pressing tube), and the slider may be connected to the second slider guide, and the second slider guide is provided in the axial direction and can move along the axial direction, and the slider 8 drives the second slider guide to move in the axial direction and further to move the pressing tube in the axial direction.

[0074] In a preferred embodiment, the pre-purge mode, i.e., the distal end of JT slot 1 is located inside vacuum insulation region 26, can be set as the product's factory default state, and the operator can complete the product pre-purge directly through the tool test process. After the tool test / pre-purge is completed, adjust to the freeze mode, where the distal end of JT slot 1 is located inside target region 25, and when freezing begins, the target region 25 will be rapidly cooled to the lowest temperature because the ablation needle has performed pre-purge.

[0075] In the description herein, terms such as "one embodiment," "one example," "particular implementation," "example," and the like, mean that the particular feature, structure, material, or characteristic described in connection with that example or example is included in at least one example or example of the present invention. In the present specification, exemplary expressions of the above terms do not necessarily refer to the same example or example. Moreover, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more examples or examples.

[0076] Finally, it should be explained that the above-mentioned embodiments are merely for illustrating the technical solutions of the present invention, and are not intended to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can understand that the technical solutions described in the above embodiments may be modified, or part or all of the technical features may be equivalently replaced, and such modifications or replacements do not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present invention. [Explanation of symbols]

[0077] 1 - JT slot; 11-JT slot straight section; 12-JT slot helix; 2- vacuum wall; 21-Needle bar; 211-needle tip; 22-inner tube; 221-Inner tube front stage; 222-inner tube rear stage; 23-external tube; 24 - gasket; 25-target area; 26-Vacuum insulation area; 27-Spring color; 28-vacuum three-way tube; 281-Three-way pipe connections; 282-Three-way pipe bypass; 291-Vacuum connecting tube; 292 - vacuum hose; 293-return air connection pipe; 294-Shunt tube; 3 - mandrel; 4-fin tube; 5-Seal assembly; 51 - sealing ring; 52 - sealing groove; 53-seal pressing member; 54-extension tube; 6-intake pipe; 7-return trachea; 8-slider; 81 - guide tube; 82-slider positioning groove; 83-central fixing hole; 84-Guide hole for intake and return air pipe; 9 - lever; 91 - Lever positioning groove; 92-Bending protection material; 10-Snap parts; 101-grip; 102 - locating pin; 103-C type ring; 120-spring; 13-external sleeve; 14-Temperature measuring line; 141 - temperature measuring point; 15-branch three-way pipe; 151 - central orifice; 153 - intake passage; 17-pressure tube; 171-Press tube thin section; 172-Pressure pipe thick part; 174 - intake slot; 18 - sealing tube; 181-seal pipe guide section; 182-seal pipe seal; 183-seal pipe connection; 19-Sealing gasket.

Claims

1. a vacuum wall, a JT slot, and a JT slot adjustment device; the vacuum wall includes a needle bar and an inner tube; the distal end of the needle bar has a needle tip; the inner tube is inserted into the needle bar, and a sandwich is formed between the inner tube and the needle bar, and the sandwich is capable of forming a vacuum; a distal end of the inner tube has a first predetermined distance from a distal end of the needle bar along an axial direction of the vacuum wall, the distal end of the inner tube being an end of the inner tube close to the needle tip; The JT slot is drilled in the inner tube, a distal end of the J-T slot is switchable between at least two adjustment positions relative to the vacuum wall, the at least two adjustment positions including a first adjustment position and a second adjustment position, the distal end of the J-T slot being an end of the J-T slot proximate to the needle tip; Among the regions distributed along the axial direction of the vacuum wall, the region in which the sandwich is located is a vacuum insulation region, and the region in which the first predetermined distance is located is a target region; the first adjustment position is within the target area; The second adjustment position is in the vacuum insulation region, the J-T slot adjustment device is used to switch the distal end of the J-T slot between the at least two adjusted positions by adjusting a position of the distal end of the J-T slot; when the distal end of the J-T slot is in the first adjustment position, the distal end of the J-T slot has a second predetermined distance along the axis of the vacuum wall from the needle tip, the second predetermined distance at least ensuring that an ice ball formed upon freezing covers the needle tip; A cryoablation needle with an adjustable J-T slot position, characterized in that when the distal end of the J-T slot is in the second adjustment position, the distal end of the J-T slot has a third predetermined distance along the axial direction of the vacuum wall between the distal end of the vacuum insulation region, the third predetermined distance at least ensuring that refrigerant returns directly from within the vacuum insulation region after being discharged from the J-T slot, and the distal end of the vacuum insulation region is an end of the vacuum insulation region that is closer to the needle tip.

2. The J-T slot includes a J-T slot straight portion and a J-T slot spiral portion, and the J-T slot straight portion and the J-T slot spiral portion are sequentially distributed from a distal end to a proximal end of the J-T slot; the JT slot adjustment device includes a first slider and a first slider guide; the first slider guide portion is connected to the JT slot straight portion, and the first slider is fixedly connected to the first slider guide portion; the first slider, the first slider guide and the JT slot straight section are controllable to move along the axial direction, thereby switching an adjustment position of the distal end of the JT slot; The cryoablation needle with an adjustable J-T slot position as described in claim 1, wherein the position of the proximal end of the J-T slot spiral portion is constant relative to the vacuum wall, the J-T slot spiral portion can expand or contract with movement of the J-T slot straight portion along the axial direction, and the proximal end of the J-T slot spiral portion is an end of the J-T slot spiral portion away from the needle tip.

3. a first seal assembly, the first seal assembly being in sealing connection with a proximal end of the inner tube, the proximal end of the inner tube being an end of the inner tube remote from the needle tip; 3. The cryoablation needle with adjustable JT slot position as recited in claim 2, wherein a dynamic seal is provided between said first seal assembly and said first slider guide.

4. the first seal assembly includes a sealing device and an extension tube; a distal end of the extension tube is sealed to a proximal end of the inner tube, the distal end of the extension tube being an end of the extension tube proximal to the needle tip; 4. The cryoablation needle with adjustable J-T slot position as described in claim 3, wherein the sealing device is sealingly connected to the proximal end of the extension tube and a dynamic seal is formed between the sealing device and the first slider guide, and the proximal end of the extension tube is an end of the extension tube remote from the needle tip.

5. the JT slot adjustment device includes a pressure tube, a second slider, and a second slider guide; a distal end of the pressure tube is connected to a proximal end of the JT slot, the distal end of the pressure tube being an end of the pressure tube close to the needle tip; The proximal end of the pressure tube is a closed structure, The second slider guide portion is provided along the axial direction, the second slider is connected to a proximal end of the pressure tube, and the second slider is slidable relative to the second slider guide portion; The cryoablation needle with an adjustable J-T slot position as described in claim 1, characterized in that the second slider, the pushing tube and the J-T slot are controllable to move synchronously along the axial direction, thereby switching the adjustment position of the distal end of the J-T slot.

6. further comprising a second seal assembly; the second seal assembly is fixedly sealed against a proximal end of the second slider guide; 6. The cryoablation needle with adjustable JT slot position as recited in claim 5, wherein said second seal assembly provides a dynamic seal between said second slider guide and said pusher tube.

7. the vacuum wall further comprises an outer tube and a gasket; the gasket is disposed between an outer wall of the distal end of the inner tube and an inner wall of the needle bar to form a sealed connection; a distal end of the outer tube is sealingly connected to a proximal end of the needle rod, a proximal end of the outer tube is sealingly connected to a proximal end of the inner tube, the distal end of the outer tube being an end of the outer tube close to the needle tip, and the proximal end of the outer tube being an end of the outer tube away from the needle tip; The outer diameter of the outer tube is larger than the outer diameter of the needle bar, and the inner diameter of the outer tube is larger than the inner diameter of the needle bar, From the distal end to the proximal end of the inner tube, the inner tube includes an inner tube front section and an inner tube rear section, in that order, an outer diameter of the inner tube rear section is larger than an outer diameter of the inner tube front section, and an inner diameter of the inner tube rear section is larger than an inner diameter of the inner tube front section, The cryoablation needle with adjustable JT slot position as claimed in claim 1, wherein the front part of the inner tube is drilled into the needle bar, and the rear part of the inner tube is drilled into the outer tube.

8. Further comprising a temperature measurement line; a distal end of the temperature measuring line is a temperature measuring point, the distal end of the temperature measuring line being an end of the temperature measuring line proximal to the needle tip; The cryoablation needle with adjustable J-T slot position as described in claim 1, characterized in that the temperature measurement point is provided at the distal end of the J-T slot and is used to measure the temperature of the distal end of the J-T slot.

9. further comprising a spring and a snap member; one end of the spring is movable synchronously with the distal end of the JT slot and is also connected to the snap member, the snap member being movable into and out of a snap position; The other end of the spring is fixed to the vacuum wall; When the snap member is in the snap position, the spring is held in a deformed state by the restriction of the snap member and the distal end of the JT slot is in the second adjustment position; The deformation state is a compression state or an extension state, 9. The cryoablation needle with adjustable J-T slot position according to claim 1, wherein when the snap member is released from the snap position, the spring is capable of generating a restoring force to return from the deformed state to a natural state, and the restoring force is capable of driving the distal end of the J-T slot to advance from the second adjustment position to the first adjustment position.

10. Spring colors are also included.

10. The cryoablation needle with adjustable J-T slot position as claimed in claim 9, wherein when the distal end of the J-T slot switches from the second adjustment position to the first adjustment position, the spring collar is used to limit the farthest distance the spring can move distally, and when the distal end of the spring is in the spring collar, the distal end of the J-T slot is in the first adjustment position.

11. The snap member includes a positioning pin and a C-ring; The positioning pin is provided on the C-ring, The C-ring is covered by an outer wall whose relative position with respect to the vacuum wall is constant; 10. The cryoablation needle with adjustable J-T slot position as claimed in claim 9, wherein the positioning pin is used to hold the spring in the deformed state when the distal end of the J-T slot is in the first adjustment position.

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