Double JT slotted cryoablation needle

Abstract

The present invention discloses a cryoablation needle with double JT slots, comprising a vacuum wall and a JT slot, 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 between the distal end of the needle bar, the JT slot comprises a first J-T slot and a second J-T slot, the first J-T slot and the second J-T slot are drilled into the inner tube, among the regions distributed in 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 distal end of the first J-T slot is in the target region, and the distal end of the second J-T slot is in the vacuum insulation region. The present invention significantly accelerates the cooling rate by passing a refrigerant fluid through two JT slots with different distal ends, respectively.

Description

[Technical field]

[0001] The present invention relates to the field of cryoablation, and in particular to a dual JT slotted cryoablation needle. [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 needle, such as the JT slot and fin tube, 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] The present invention proposes a double JT slotted cryoablation needle to address the above problems of the prior art and solve the problem of the slow cooling rate of the prior art.

[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 dual JT slotted cryoablation needle, comprising a vacuum wall and a JT slot, 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 slots include a first J-T slot and a second J-T slot; the first J-T slot and the second J-T slot are drilled in the inner tube; 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; a distal end of the first J-T slot is located within the target area, the distal end of the first J-T slot being an end of the first J-T slot proximate the needle tip; a distal end of the second J-T slot is located within the vacuum insulation region, the distal end of the second J-T slot being an end of the second J-T slot proximate to the needle tip; the distal end of the first J-T slot has a second predetermined distance along the axial direction of the vacuum wall between the needle tip and the first J-T slot, 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 first J-T slot, wherein the refrigerant fluid exchanges heat with a material outside the entire target area while returning from the inside of the target area; The distal end of the second J-T slot has a third predetermined distance along the axial direction of the vacuum wall with the distal end of the vacuum insulation region, the third predetermined distance at least ensures that the refrigerant returns directly from the vacuum insulation region after being discharged from the second J-T slot, and there is only a relatively static refrigerant in the target region and there is 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 cooling system further includes a switching assembly, the switching assembly being connected to the first J-T slot and the second J-T slot, respectively, and the switching assembly being used to switch refrigerant between the first J-T slot and the second J-T slot.

[0009] Preferably, the switching assembly includes a conditioning chamber, a refrigeration passage, a pre-purge passage and a sealing member, wherein: The refrigeration passage and the pre-purge passage are each connected to the adjustment chamber, the refrigeration passage further communicates with the first J-T slot; The pre-purge passage is further connected to the second J-T slot, The adjustment chamber is further connected to a refrigerant passage through which a refrigerant passes, the sealing member is provided in the adjustment chamber, and the sealing member includes at least a first adjustment position and a second adjustment position in the adjustment chamber; When the sealing member is in the first adjustment position, the sealing member directly or indirectly separates the freezing passage and the refrigerant passage, When the sealing member is in the second adjustment position, the sealing member directly or indirectly separates the pre-purge passage and the refrigerant passage.

[0010] Preferably, the sealing member is a sealing ball.

[0011] Preferably, the device further includes a sealing member adjustment device, the sealing member adjustment device being used to adjust the sealing member to switch between the first adjustment position and the second adjustment position.

[0012] Preferably, the seal member adjustment device includes a pull wire and a pull wire passage; a distal end of the puller wire is connected to the sealing member; The puller wire is drilled through the puller wire passage, The puller wire is controllable to move along the puller wire passageway, thereby actuating the seal member to switch between the first and second adjustment positions.

[0013] Preferably, the device further includes a guide member, said guide member being connected to a proximal end of said puller wire; The guide member is controllable to move the puller wire along the puller wire passageway, thereby actuating the sealing member to switch between the first and second adjustment positions.

[0014] Preferably, the spring and snap member further comprises: one end of the spring is movable in synchronism with the distal end of the puller wire 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 sealing member is in the first 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 that returns the deformed state to its natural state, and the restoring force can drive the movement of the pull wire and further drive the sealing member to advance from the first adjustment position to the second adjustment position.

[0015] Preferably, the device further includes a spring stopper. The relative position of the spring stopper with respect to the vacuum wall is constant, One end of the spring fixed to the vacuum wall is connected to the spring stopper.

[0016] Preferably, the cooling system includes a first refrigerant passage, a second refrigerant passage, a refrigeration valve, and a pre-purge valve, wherein: the first refrigerant passage is connected to the first J-T slot; the second refrigerant passage is connected to the second J-T slot; The refrigeration valve is provided in the first refrigerant passage, The pre-purge valve is provided in the second refrigerant passage.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) In the cryoablation needle with double JT slots provided by the present invention, when the refrigerant fluid is passed through the second J-T slot, freezing begins, and all the transport lines on the main side and the end of the cryoablation needle can be pre-purged (cooled). In addition, this pre-purging process does not consume any cold air in the target area, so all the cold air is used to cool the transport lines, and as a result, the cooling process of this transport line is the fastest. Furthermore, no cold air is released in the target area during pre-purging, so no frost or ice will occur in the target area, and the formal treatment can be carried out directly.

[0019] (2) In the double JT slotted cryoablation needle provided by the present invention, the cryoablation needle after pre-purging is not only cooled in the target area of ​​the vacuum wall, but also starts freezing when the refrigerant fluid is passed through the first J-T slot, and all the heat load is only on the target area and the tumor tissue outside it, so the cooling rate of this freezing process is greatly accelerated.

[0020] (3) In the case of the double JT slotted cryoablation needle provided by the present invention, after the tool testing process is completed, the pre-purge mode can be kept on and the inside of the vacuum insulation area (the distal end of the JT slotted sleeve) can be kept at the lowest temperature, and no cold air is released at the target area, so that operations such as puncturing, scanning and positioning can be performed. After being punctured at the designated position, the cryomode can be adjusted, at which point the inside of the target area is directly and instantly cooled from normal temperature to the lowest temperature, which enables the extreme and rapid cooling of the formal treatment stage.

[0021] (4) The double JT slot sleeved cryoablation needle 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 is applicable not only to percutaneous puncture cryoablation instruments, but also to cryoablation instruments for natural orifice procedures.

[0022] Of course, any given product embodying the present invention need not necessarily achieve all of the above advantages simultaneously. [Brief description of the drawings]

[0023] 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 derive other drawings based on these drawings without any creative efforts.

[0024] [Figure 1]FIG. 2 illustrates the adjustment principle of the JT slot in a rigid cryoablation needle with double JT slots according to one embodiment of the present invention. [Diagram 2] 1A-1D are diagrams illustrating the adjustment principle of the JT slot in a flexible cryoablation needle with double JT slots according to one embodiment of the present invention. [Diagram 3] FIG. 1 illustrates the pre-purge mode of a rigid cryoablation needle with dual JT slots according to a preferred embodiment of the present invention. [Figure 4] FIG. 4 is an enlarged view of part I in FIG. [Diagram 5] FIG. 4 is a cross-sectional view taken along the line AA in FIG. [Figure 6] FIG. 1 illustrates the freezing mode of a rigid cryoablation needle with dual JT slots according to a preferred embodiment of the present invention. [Figure 7] FIG. 7 is an enlarged view of part II in FIG. [Figure 8] FIG. 2 is a schematic diagram showing the vacuum wall of a flexible cryoablation needle with double JT slots according to a preferred embodiment of the present invention. [Figure 9] FIG. 1 illustrates a pre-purge mode of a flexible cryoablation needle with dual JT slots according to a preferred embodiment of the present invention. [Figure 10] FIG. 10 is an enlarged view of part I in FIG. [Figure 11] 10 is a cross-sectional view taken along the line AA in FIG. 9. [Figure 12] FIG. 1 illustrates the freezing mode of a flexible cryoablation needle with dual JT slots according to a preferred embodiment of the present invention. [Figure 13] FIG. 13 is an enlarged view of part II in FIG. [Figure 14] 1 is a schematic diagram of a slider according to a preferred embodiment of the present invention. [Figure 15] 1 is a schematic diagram of a snap ring according to a preferred embodiment of the present invention. [Figure 16] FIG. 2 is a schematic diagram of a rigid cryoablation needle in accordance with another preferred embodiment of the present invention. [Figure 17]1 is a schematic diagram of a flexible cryoablation needle in accordance with another preferred embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] 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.

[0026] 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.

[0027] 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.

[0028] In the present description, "plurality" means, for example, two, three, four, etc., unless otherwise limited.

[0029] 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.

[0030] 1 and 2 are diagrams illustrating the adjustment principle of the JT slots in a cryoablation needle with dual JT slots according to one embodiment of the present invention.

[0031] 1 and 2, the cryoablation needle with double JT slots according to this embodiment includes a vacuum wall 2 and a JT slot 1, 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.

[0032] 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.

[0033] 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 JT slot 1 includes a first J-T slot 11 and a second J-T slot 12 , and the first J-T slot 11 and the second J-T slot 12 are drilled in the inner pipe 22 .

[0035] The distal end of the first J-T slot 11 is located within the target area 25, and the distal end of the first J-T slot 11 is the end of the first J-T slot 11 proximal to the needle tip 211. Passing a refrigerant through the first J-T slot 11 may be understood to be in a freezing mode.

[0036] The distal end of the second J-T slot 12 is located within the vacuum insulation region 26, and the distal end of the second J-T slot 12 is the end of the second J-T slot 12 near the needle tip 211. Passing the refrigerant through the second J-T slot 12 may be understood to be in a pre-purge mode.

[0037] The distal end of the first J-T slot 11 has a second predetermined distance along the axial direction of the vacuum wall 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 the vacuum insulation area after being expelled from the first J-T slot, where the refrigerant fluid exchanges heat with materials outside the entire target area while returning from within the target area.

[0038] The distal end of the second J-T slot 12 has a third predetermined distance along the axial direction of the vacuum wall with the distal end of the vacuum insulation region, the third predetermined distance at least ensures that the refrigerant fluid returns directly from the vacuum insulation region after being discharged from the second J-T 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] In one embodiment, the use process of the above-mentioned double JT slotted cryoablation needle is as follows: before the procedure, 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; the tool test first executes the rewarming stage, 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 executes 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. During 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 during the entire stage, it is observed whether there is gas leakage at the needle tip immersed in saline, and if there is no leakage, the airtightness is proven to be 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 treatment time for ablating a tumor of the same size is shortened, or a larger ablation range (ice ball) is formed 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.

[0043] In a preferred embodiment, referring to Fig. 8, 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.

[0044] In a preferred embodiment, switching between the pre-purge mode and the freeze mode is accomplished by a switching assembly 15, which is connected to the first J-T slot and the second J-T slot, respectively, and is used to switch the refrigerant between the first J-T slot and the second J-T slot.

[0045] In one embodiment, the switching assembly 15 includes a refrigeration passage 1511, a conditioning chamber 1512, a pre-purge passage 152, and a sealing member 16. Here, the refrigeration passage 1511 and the pre-purge passage 152 are each in communication with the conditioning chamber 1512. The refrigeration passage 1511 is further in communication with the first J-T slot 11, and the pre-purge passage 152 is further in communication with the second J-T slot 12. The conditioning chamber 1512 is further in communication with a refrigerant passage 153 that passes a refrigerant.

[0046] Here, the sealing member 16 is provided in the adjustment chamber 1512, and the sealing member 16 includes at least a first adjustment position and a second adjustment position in the adjustment chamber 1512.

[0047] When the sealing member 16 is in the first adjustment position (at the distal end of the adjustment chamber 1512), as shown in Figs. 3, 4, 9 and 10, the sealing member directly or indirectly separates the freezing passage 1511 from the refrigerant passage 153. In this case, the refrigerant gas injected from the intake pipe 6 must pass through the refrigerant passage 153, the adjustment chamber 1512, the pre-purge passage 152 and the second J-T slot 12 to enter the distal end of the vacuum insulation region 26, resulting in a pre-purge mode. In this case, the return air can be discharged from the gap between the second J-T slot 12 and the inner pipe 22, the gap between the switching assembly 15 and the inner pipe 22, and the return air pipe 7.

[0048] When the sealing member 16 is in the second adjustment position (proximal end of the adjustment chamber 1512), as shown in Figures 6, 7, 12, and 13, the sealing member 16 directly or indirectly separates the pre-purge passage 152 from the refrigerant passage 153. In this case, the refrigerant gas injected from the intake pipe 6 must pass through the refrigerant passage 153, the adjustment chamber 1512, the freezing passage 1511, and the first J-T slot 11 to enter the distal end inside of the target area 25, resulting in a freezing mode. In this case, the return air can be routed in the same way as when the sealing member 16 is in the first adjustment position.

[0049] In one embodiment, the adjustment chamber 1512 is provided in the inner tube 22, and the radial cross section of the adjustment chamber 1512 may be flattened, for example, in the shape of a straight groove, a rectangle, an ellipse, etc., thereby creating space for air return between the adjustment chamber 1512 and the inner tube 22 (circular cross section).

[0050] In a preferred embodiment, the sealing member 16 utilizes a sealing ball.

[0051] In a preferred embodiment, the device further includes a seal member adjustment device, which is used to adjust the adjustable seal member to switch between a first adjustment position and a second adjustment position.

[0052] The seal member adjustment device includes a pull wire 17 and a pull wire passage 1513, where a distal end of the pull wire 17 is connected to the seal member 16. The pull wire 17 is drilled through the pull wire passage 1513. The pull wire 17 is controllable to move along the pull wire passage 1513, thereby actuating the seal member 16 to switch between a first adjustment position and a second adjustment position.

[0053] In one embodiment, the vacuum system further includes a mandrel 3, the mandrel 3 being disposed along an axial direction of the vacuum wall. A pull wire 17 is disposed within the mandrel 3. The vacuum system further includes a seal assembly 5, the seal assembly 5 being used to form a dynamic seal between the mandrel 3 and the pull wire 17.

[0054] In one embodiment, the seal assembly 5 includes a seal ring 51, a seal groove 52, and a seal pressing member 53. Here, 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 inside of the seal ring 51 and the seal pressing member 53, so that the seal ring 51 is pressed radially between the mandrel 3 and the seal groove 52 and deformed to 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 made of a low-temperature resistant fluorine-based polymer and a metal spring.

[0055] In one embodiment, referring to Figures 9 and 12, 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. In a preferred embodiment, the mandrel 3 includes a thicker mandrel section 31 and a thinner mandrel section 32, and the puller wire 17 includes a thicker puller wire section 171 and a thinner puller wire section 172. The thinner puller wire section 172 is disposed within the thinner mandrel section 32, and the thicker puller wire section 171 is disposed within the thicker mandrel section 131.

[0056] In a preferred embodiment, the guide member further includes a guide member connected to a proximal end of the puller wire 17, the guide member being controllable to move the puller wire along the puller wire passageway, thereby actuating the sealing member to switch between the first and second adjustment positions.

[0057] In one embodiment, the guide member is in the form of a slider. See Figures 3, 6, 9, 12, and 14. The slider 8 includes a guide tube 81, which is arranged along the axial direction of the vacuum wall. The guide tube 81 is provided with a central fixing hole 83, and the distal end of the puller wire 3 is fixed to the central fixing hole 83.

[0058] In one embodiment, the slider 8 further includes an intake / return pipe guide hole 84 provided in the guide tube 81. The intake pipe 6 and the return pipe 7 pass through the intake / return pipe guide hole 84.

[0059] In one embodiment, the adjustment of the position of the sealing member can be achieved by manual back and forth adjustment or a prefabricated spring 120, and further includes a snap member 10. Here, one end of the spring 120 is movable in synchronization with the distal end of the pull wire 17 and is also connected to the snap member 10, which can move into and out of the snap position. The other end of the spring 120 is fixed against the vacuum wall. Referring to Figs. 3 and 9, when the snap member 10 is in the snap position, the spring 120 is held in a deformed state by the restriction of the snap member 10, and the sealing member 16 is in a first adjustment position. When the snap member 10 is released from the snap position, the spring 120 can generate a restoring force to return from the deformed state to a natural state, and the restoring force can drive the movement of the pull wire 17 and further drive the sealing member 16 to proceed from the first adjustment position to the second adjustment position. In this embodiment, the distal end of the spring 120 does not change its position relative to the vacuum wall, and the proximal end of the spring 120 is connected to the snap member 10, and when the sealing member 16 is in the first adjustment position, the deformation state of the spring 120 is in a compressed state. When the snap member 10 is released from the snap position, the restoring force (elastic force) of the spring 120 drives the pull wire to move, and further drives the sealing member 16 to proceed from the first adjustment position to the second adjustment position.

[0060] In another embodiment, the relative position of the proximal end of the spring 120 with respect to the vacuum wall does not change, and the proximal end of the spring 120 may be provided to be connected to the snap member 10, and when the snap member 10 is in the snap position, the spring 120 is held in an extended state by the constraint of the snap member 10, and the sealing member 16 is in the first adjustment position. When the snap member 10 is disengaged from the snap position, the restoring force (tensile force) of the spring 120 drives the pull wire 17 to move, which in turn drives the sealing member 16 to advance from the first adjustment position to the second adjustment position.

[0061] In a preferred embodiment, the spring stopper 27 is further included, and the spring stopper 27 has a fixed position relative to the vacuum wall. Referring to Figures 3 and 9, the distal end of the spring 120 is connected to the spring stopper 27, and the proximal end of the spring 120 is connected to the guide tube 81 of the slider 8, so that the spring drives the slider to further move the puller wire.

[0062] In one embodiment, as shown in Figs. 3 and 9, the snap member 10 includes a positioning pin 102. In this embodiment, it further includes a lever 9, which is provided at the proximal end of the cryoablation needle, which makes 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, it is only necessary to pull out the positioning pin 102 from the lever positioning groove 91 and the slider positioning groove 82.

[0063] 15, 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.

[0064] 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.

[0065] 3, 6, 9 and 12, 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.

[0066] In a preferred embodiment, in order to enlarge 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 enlarged, and furthermore, the internal volume of the proximal end of the vacuum wall needs to be enlarged. 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, 6, 9 and 12, the inner tube front section 221 is located inside the needle bar 21, the inner tube rear section 222 is located inside the outer tube 23, and the adjustment chamber 1512 is provided in the inner tube rear section 222.

[0067] In one embodiment, the switching between the first J-T slot and the second J-T slot can also be realized by two refrigerant passages, specifically including a first refrigerant passage, a second refrigerant passage, a freezing valve 20 and a pre-purge valve 20', where the first refrigerant passage is connected to the first J-T slot 11, the second refrigerant passage is connected to the second J-T slot 12, the freezing valve 20 is provided in the first refrigerant passage, and the pre-purge valve 20' is provided in the second refrigerant passage.

[0068] Now, when the pre-purge valve 20' is opened, the second refrigerant passage is open and refrigerant can enter the distal end of the second J-T slot 12, which is in the pre-purge mode. When the freeze valve 20 is opened, the first refrigerant passage is open and refrigerant can enter the distal end of the first J-T slot 11, which is in the freeze mode.

[0069] In a preferred embodiment, the mandrel 3 is further included, and the mandrel 3 is provided along the axial direction of the vacuum wall.

[0070] In a preferred embodiment, the mandrel 3 further includes a fin tube 4 for improving heat dissipation function, and the fin tube 4 is provided on the outer wall of the mandrel 3 .

[0071] In one embodiment, the fin tube 4 can be used as the first refrigerant passage, one end of the fin tube 4 is connected to the first J-T slot, the other end is connected to the intake pipe 6, and a refrigeration valve is provided on the intake pipe 6. The mandrel 3 can be connected to the second J-T slot as the second refrigerant passage, and a pre-purge valve 20' is provided on the mandrel 3. Please refer to Figures 16 and 17.

[0072] In another embodiment, the mandrel 3 may be connected to a first J-T slot as a first coolant passage, and the fin tube 4 may be connected to a second J-T slot as a second coolant passage.

[0073] 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 Figs. 3, 6, 9 and 12.

[0074] In a preferred embodiment, the pre-purge mode, which passes coolant fluid through the second J-T slot, can be set as the factory default state of the product, and the operator can complete the pre-purge of the product directly through the tool test process. After the tool test / pre-purge is completed, the freeze mode is adjusted to pass coolant fluid through the first J-T slot, and when freezing begins, the target area 25 is rapidly cooled to the lowest temperature because the ablation needle has been pre-purged.

[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; 11-1st J-T slot; 12-2nd J-T slot; 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 stopper; 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; 31-Mandrel thick part; 32-mandrel thin section; 4-fin tube; 5-Seal assembly; 51 - sealing ring; 52 - sealing groove; 53-seal pressing member; 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; 10-Snap parts; 101-grip; 102 - locating pin; 103-C type ring; 120-spring; 13-external sleeve; 15-Switch assembly; 1511 - Refrigerated aisle; 1512-Adjustment room; 1513 - towing wire passage; 152-Pre-purge passage; 153 - refrigerant passage; 16-sealed ball; 17- Traction wire; 171- traction wire thick part; 172- traction wire thin section; 20-Refrigeration valve; 20'-Prepurge valve.

Claims

1. a vacuum wall and a JT slot; 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 slots include a first JT slot and a second JT slot; the first J-T slot and the second J-T slot are drilled in the inner tube; 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; a distal end of the first J-T slot is located within the target area, the distal end of the first J-T slot being an end of the first J-T slot proximate to the needle tip; a distal end of the second J-T slot is located within the vacuum insulation region, and the distal end of the second J-T slot is an end of the second J-T slot proximate to the needle tip; At the same time, refrigerant is passed through only one of the first J-T slot and the second J-T slot; a distal end of the first J-T slot having a second predetermined distance along the axis of the vacuum wall from the tip of the needle, the second predetermined distance being at least sufficient to ensure that an ice ball formed by freezing covers the tip of the needle; a distal end of the second 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 second J-T slot, and the distal end of the vacuum insulation region is an end of the vacuum insulation region proximal to the needle tip.

2. 2. The dual J-T slotted cryoablation needle of claim 1, further comprising a switching assembly, the switching assembly being connected to the first J-T slot and the second J-T slot, respectively, the switching assembly being used to switch refrigerant between the first J-T slot and the second J-T slot.

3. the switching assembly includes a conditioning chamber, a refrigeration passage, a pre-purge passage, and a sealing member; The refrigeration passage and the pre-purge passage are each connected to the adjustment chamber, the refrigeration passage further communicates with the first JT slot; The pre-purge passage is further connected to the second J-T slot, The adjustment chamber is further connected to a refrigerant passage through which a refrigerant passes, the sealing member is provided in the adjustment chamber, and the sealing member includes at least a first adjustment position and a second adjustment position in the adjustment chamber; When the sealing member is in the first adjustment position, the sealing member directly or indirectly separates the freezing passage and the refrigerant passage, 3. The cryoablation needle with dual JT slots as claimed in claim 2, wherein when the sealing member is in the second adjustment position, the sealing member directly or indirectly separates the pre-purge passage from the refrigerant passage.

4. The double JT slotted cryoablation needle of claim 3, wherein the sealing member is a sealing ball.

5. 4. The dual J-T slotted cryoablation needle of claim 3, further comprising a seal member adjustment device, the seal member adjustment device being used to adjust the seal member to switch between the first and second adjustment positions.

6. the seal member adjustment device includes a pull wire and a pull wire passage; a distal end of the puller wire is connected to the sealing member; The puller wire is drilled through the puller wire passage, 6. The dual JT slotted cryoablation needle of claim 5, wherein the puller wires are controllable to move along the puller wire passageway, thereby actuating the sealing member to switch between the first and second adjusted positions.

7. a guide member connected to a proximal end of the puller wire; 7. The dual J-T slotted cryoablation needle of claim 6, wherein the guide member is controllable to move the puller wires along the puller wire passageway, thereby actuating the sealing member to switch between the first and second adjusted positions.

8. further comprising a spring and a snap member; one end of the spring is movable in synchronism with the distal end of the puller wire 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 sealing member is in the first adjustment position; The deformation state is a compression state or an extension state, 8. The cryoablation needle with dual J-T slots according to claim 6 or 7, characterized in that when the snap member is released from the snap position, the spring can generate a restoring force from the deformed state back to a natural state, and the restoring force can drive the movement of the puller wire and further drive the sealing member to advance from the first adjustment position to the second adjustment position.

9. Further comprising a spring stopper; The relative position of the spring stopper with respect to the vacuum wall is constant, 9. The double JT slotted cryoablation needle of claim 8, wherein one end of the spring fixed against the vacuum wall is connected to the spring stopper.

10. a first refrigerant passage, a second refrigerant passage, a freeze valve, and a pre-purge valve; the first refrigerant passage is connected to the first JT slot; the second refrigerant passage is connected to the second JT slot; The freezing valve is provided in the first refrigerant passage, The double JT slotted cryoablation needle of claim 1, wherein the pre-purge valve is provided in the second refrigerant passage.

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