CN113796945B - Cryoablation tube - Google Patents

Abstract

Embodiments of the present disclosure provide a cryoablation tube comprising a delivery segment and a freezing segment, the delivery segment comprising an operating handle and a delivery catheter; the delivery catheter has a distal end and a proximal end; the freezing section is connected with the distal end of the conveying catheter, the operating handle is connected with the proximal end of the conveying catheter, the freezing section comprises a contractible and expandable double-layer bag body, and the surface of the bag film of the double-layer bag body is coated with a polymer film containing high thermal conductivity filler; the double-layer balloon body consists of an outer balloon and an inner balloon arranged in the outer balloon; a vacuum pump body is arranged in the operating handle; the conveying catheter is internally provided with a vacuum inner cavity, and a gap between the outer balloon and the inner balloon is communicated with the vacuum pump through the vacuum inner cavity. The cryoablation tube can efficiently transfer the refrigerant to human tissues at the low temperature of the balloon section, thereby achieving the purpose of rapidly cooling the tissues, greatly reducing the treatment time and reducing the treatment cost.

Description

Cryoablation tube

Technical Field

The present disclosure relates to the field of medical devices, and more particularly to a cryoablation tube with efficient refrigeration.

Background

Atrial fibrillation (abbreviated as atrial fibrillation) is the most common sustained arrhythmia, the most serious disturbance of atrial electrical activity. Studies have shown that: the pulmonary veins have spontaneous electrical activity, and the upper two pulmonary veins are the main ectopic excitation sites for atrial fibrillation of pulmonary vein origin. After electrical isolation of the pulmonary veins, the ability of most pulmonary veins to self-initiate electrical discharge activity immediately disappears, and even induction by drugs and the like cannot occur. At present, aiming at paroxysmal atrial fibrillation patients, an ablation strategy of performing circumferential pulmonary vein ablation and taking pulmonary vein electrical isolation as an endpoint is a safe, effective and simple-to-operate treatment method. The cryoablation technology absorbs heat through the evaporation of liquid refrigerant, takes away the heat of the tissue, reduces the temperature of the target ablation part, and damages the abnormal electrophysiological cell tissue, thereby reducing the risk of arrhythmia. The cryoablation technology has the advantages of simple operation, accurate operation target point and stable adhesion; the operation time and the exposure time are short; the incidence rate of surgical complications is low; the learning time of operators is short, and rapid progress has been made in recent years.

The cryoablation catheter portion carries most of the functional roles of the cryoablation technology, the implementation of cryoablation and the safety protection of patients are required to be realized in the catheter portion, and the design of the catheter portion plays a vital role in realizing and improving the treatment effect. Catheter portions of cryoablation products currently on the market include: a conveying section and a freezing section. In the surgical treatment process, the refrigerant is conveyed to the far-end saccule from the near-end interface through the metal pipe, and the refrigerant evaporates and absorbs heat when reaching the saccule, so that the temperature of the target ablation part is reduced, the pulmonary vein potential isolation is realized, and the aim of treating atrial fibrillation is fulfilled. However, the cryoablation product in the prior art cannot timely transmit low temperature to human tissues, delays the treatment process, and increases the air outlet amount of the metal tube in order to achieve good low temperature effect, thereby increasing the refrigeration cost. Thus, there is a need for improvements in cryoablation tubes.

Disclosure of Invention

One of the embodiments of the present disclosure provides a cryoablation tube comprising a delivery segment and a freezing segment, the delivery segment comprising an operating handle and a delivery catheter; the delivery catheter has a distal end and a proximal end; the freezing section is connected with the distal end of the conveying catheter, the operating handle is connected with the proximal end of the conveying catheter, the freezing section comprises a contractible and expandable double-layer bag body, and the surface of the bag film of the double-layer bag body is coated with a polymer film containing high thermal conductivity filler; the double-layer balloon body consists of an outer balloon and an inner balloon arranged in the outer balloon; a vacuum pump body is arranged in the operating handle; the conveying catheter is internally provided with a vacuum inner cavity, and a gap between the outer balloon and the inner balloon is communicated with the vacuum pump through the vacuum inner cavity.

Drawings

The present specification will be further elucidated by way of example embodiments, which will be described in detail by means of the accompanying drawings. The embodiments are not limiting, in which like numerals represent like structures, wherein:

FIG. 1 is a schematic illustration of an exemplary structure of a cryoablation catheter shown in accordance with some embodiments of the present disclosure;

FIG. 2 is a schematic illustration of an exemplary construction of a freeze section of a delivery section catheter according to some embodiments of the present disclosure;

FIG. 3 is a cross-sectional view taken along the direction A-A in FIG. 1;

FIG. 4 is a cross-sectional view taken along the direction B-B in FIG. 1;

FIG. 5 is a schematic illustration of an exemplary configuration of an operating handle of a cryoablation catheter shown in accordance with some embodiments of the present disclosure;

FIG. 6 is an enlarged schematic view of the structure at C in FIG. 5;

FIG. 7 is a schematic view of a gas flow path within a coaxial tube within an operating handle according to some embodiments of the present disclosure;

FIG. 8 is a cross-sectional view taken in the direction D-D of FIG. 7;

FIG. 9 is a schematic illustration of a gas flow path of a delivery segment catheter body according to some embodiments of the present disclosure;

FIG. 10 is a cross-sectional view taken along the direction E-E in FIG. 9;

FIG. 11 is a schematic illustration of a gas flow path of a freeze section of a conveying-section conduit according to some embodiments of the present disclosure;

in the figure: 1. a conveying section; 11. a vacuum lumen; 111. a proximal outer tube opening; 112. a distal outer tube opening;

2. a freezing section; 21. an outer balloon; 22. an inner balloon; 23. a thermocouple;

3. an operation handle; 31. a vacuum pump body; 32. a pressure reducing valve; 33. a fluid interface; 34. a connector; 35. a coaxial pipe; 36. an optical sensor; 37. an electrical interface; 38. a push button; 39. a three-way joint; 391. a center shaft; 310. a knob; 311. a pull wire; 312. an adjustable bend section;

4. a delivery catheter; 42. an outer tube; 43. an inner tube; 44. a metal tube; 441. winding; 45. a sleeve is arranged inside.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings that are required to be used in the description of the embodiments will be briefly described below. It is apparent that the drawings in the following description are only some examples or embodiments of the present specification, and it is possible for those of ordinary skill in the art to apply the present specification to other similar situations according to the drawings without inventive effort. Unless otherwise apparent from the context of the language or otherwise specified, like reference numerals in the figures refer to like structures or operations.

It will be appreciated that "system," "apparatus," "unit" and/or "module" as used herein is one method for distinguishing between different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

As used in this specification and the claims, the terms "a," "an," "the," and/or "the" are not specific to a singular, but may include a plurality, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that the steps and elements are explicitly identified, and they do not constitute an exclusive list, as other steps or elements may be included in a method or apparatus.

The cryoablation technology absorbs heat through the evaporation of liquid refrigerant, takes away the heat of the tissue, reduces the temperature of the target ablation part, and damages the abnormal electrophysiological cell tissue, thereby reducing the risk of arrhythmia. The cryoablation technique needs to be implemented: 1) The liquefied refrigerant can be effectively transported from the equipment end to the balloon end; 2) The balloon can be accurately and easily positioned to the pulmonary vein ostium; 3) The balloon rupture is detected and protected to a certain extent; 4) Whether the blood is permeated due to material rupture in the operation process can be monitored in real time so as to judge whether the ablation process is performed. In some embodiments, the refrigerant conveyed by the metal tube in cryoablation is sprayed out from the balloon section through a plurality of air outlet holes with a certain size and a certain aperture, the refrigerant changes into a gas state from a liquid state in the spraying process, the evaporation absorbs heat, the temperature in the balloon is rapidly reduced, and then the balloon is used for conducting low temperature to the abutted human tissue, so that the frostbite of the pathological tissue cells is inactivated, and the conduction of abnormal potential is blocked. Whether the balloon can effectively conduct low temperature to the tissue is the key of whether ablation is successful, and the timeliness of treatment is determined by the heat conductivity of the balloon.

Therefore, the embodiment of the specification provides a high-efficiency refrigerating cryoablation tube, the balloon section is coated with a film forming substance containing high-heat conductivity filler, and the refrigerant can be efficiently transmitted to human tissues at the low temperature of the balloon section, so that the aim of rapidly cooling the tissues is fulfilled, the treatment time is greatly shortened, and the treatment cost is reduced.

The cryoablation tubes according to embodiments of the present application will be described in detail below with reference to fig. 1-11. It is noted that the following examples are only for explaining the present application and are not to be construed as limiting the present application.

A cryoablation tube, as shown in figures 1-3, comprising a delivery segment 1 and a freezing segment 2, the delivery segment 1 comprising an operating handle 3 and a delivery catheter 4; the delivery catheter 4 has a distal end and a proximal end; the freezing section 2 is connected with the distal end of the conveying conduit 4, the operating handle 3 is connected with the proximal end of the conveying conduit 4, the freezing section 2 comprises a contractible and expandable double-layer bag body, and the surface of the bag film of the double-layer bag body is coated with a polymer film containing high thermal conductivity filler; the double-layer balloon body consists of an outer balloon 21 and an inner balloon 22 arranged in the outer balloon 21; the operating handle 3 is internally provided with a vacuum pump body 31; the conveying catheter 4 is internally provided with a vacuum inner cavity 11, and a gap between the outer balloon 21 and the inner balloon 22 is communicated with a vacuum pump body 31 through the vacuum inner cavity 11.

If the balloon material has low thermal conductivity, the low temperature transferred from the inner balloon cannot be effectively transferred to the human tissue abutting the outer balloon. The cryoablation tube of the embodiment has the advantages that the balloon section is coated with the film forming substance containing the high-heat-conductivity filler, and the refrigerant can be efficiently transmitted to human tissues at the low temperature of the balloon section, so that the aim of rapidly cooling the tissues is fulfilled. If the folded balloon is still unable to be fully unfolded after being inflated, the folded balloon has more folds, the surface of the balloon is not smooth, the adhesion between the inner balloon 22 and the outer balloon 21 is affected, and the low temperature of the refrigerant in the inner balloon cannot be effectively transferred to the adhered outer balloon, so that the refrigerant is transferred to human tissues. In this embodiment, the vacuum pump body 31 and the vacuum cavity 11 are used for evacuating the space between the inner balloon and the outer balloon, so that the vacuum state between the vacuum cavity 11 and the inner balloon and the vacuum state between the inner balloon and the outer balloon are realized during cryoablation, the inner balloon and the outer balloon are always in a close-fitting state, the refrigerant is conveyed into the inner balloon 22 at the tail end of the balloon, the evaporation absorbs heat, the whole inner balloon 22 is in a low-temperature environment, and the whole inner balloon 22 is in the same low-temperature environment as the outer balloon 21 which is in contact with the inner balloon, so that heat of human tissues in contact with the outer balloon 21 is taken away, and cryoablation is realized.

In some embodiments, a solution of a film-forming substance containing a filler of high thermal conductivity is deposited as a fine mist in a vacuum chamber by high pressure spraying onto the inner and outer balloon surfaces, and finally a polymer film is formed on the balloon surfaces. In some embodiments, the film-forming material solution may include, but is not limited to, polyurethane, polysiloxane, and the like. The polyurethane, polysiloxane and other film forming substances have good adhesive capability and can be uniformly coated on the surface of the saccule, so that the saccule has good flexibility. The inner balloon can be effectively stretched and fully abutted with the outer balloon when inflated, and the outer balloon can be fully abutted with tissues, so that low temperature is effectively transferred from the inside of the balloon to the tissues outside the balloon. In some embodiments, the film forming material contains 5% to 15% high thermal conductivity filler. Wherein, the high thermal conductivity filler refers to a filler filled in a film forming substance solution for increasing the thermal conductivity coefficient of the material. Such as graphene, carbon fiber materials, and the like. The high thermal conductivity filler is uniformly dispersed in the film forming material and then coated on the surface of the balloon along with the film forming material. The film thickness of the polymer film finally formed on the surface of the balloon can be controlled by adjusting the spraying time and the concentration of the solution, so as to adjust the extensibility and the thermal conductivity of the balloon. The high thermal conductivity of the high thermal conductivity filler can effectively make up the defect of the high polymer material for the saccule in heat transfer,under the condition that the balloon and human tissues are fully attached, the low temperature in the balloon can be efficiently conducted to the human tissues through the surface of the balloon, so that the indistinguishable temperature of the inner surface and the outer surface of the balloon is realized, the utilization of the refrigerating capacity of the refrigerant is further maximized, and the refrigerating time and the refrigerating cost are reduced. In the ex vivo simulated tissue test protocol, the simulated tissue is a hydrogel material approximating human tissue, which is shaped to approximate the vestibule of the pulmonary vein (the pulmonary vein isolation treatment site). The refrigerant with uniform refrigerating capacity was released from the balloon, evaporated to absorb heat, and the temperature of the tissue was measured at 40s by a thermocouple simulating the tissue at a depth of 1mm from the outer surface of the balloon, and the specific test results are shown in table 1 below. Comparative example 1 in Table 1 is the cryoablation catheter Arctic Front ^TM The balloon catheter is made of modified polyurethane and/or modified polyethylene terephthalate (PET) without film forming coating, and the catheter in the embodiment has better heat conduction performance than the film forming material containing carbon fiber under the condition that the high heat conductivity filler is added in the same amount. The high thermal conductivity filler has better heat conduction performance under the addition amount of 5-15%, and with the further increase of the addition amount, for example, to 20%, the filler can generate aggregation phenomenon, and the film forming uniformity of film forming substances is affected, but the heat conduction performance is reduced. The above results demonstrate that under conditions of uniform temperature within the balloon, the balloon containing the high thermal conductivity filler can efficiently deliver the low temperature within the balloon to the abutted tissue, and therefore, at the prescribed treatment temperature, less refrigerant flow and treatment time can also achieve ablation, thereby improving treatment efficiency.

TABLE 1 refrigeration test of balloon catheters coated with film forming substances containing fillers of different high thermal conductivity

As shown in fig. 3 to 6, the delivery catheter 4 includes a catheter body and an outer tube 42, an inner tube 43, and a metal tube 44 mounted inside the catheter body. The vacuum inner cavity 11 is arranged in the outer tube 42, a proximal outer tube opening 111 is formed in the proximal end of the vacuum inner cavity 11, the proximal outer tube opening 111 is led to the vacuum pump body 31, a distal outer tube opening 112 is formed in the distal end of the vacuum inner cavity 11, and the outer balloon 21 and the inner balloon 22 are in sealing connection with the outer tube 42 in the conveying catheter 4; the space between the outer balloon 21 and the inner balloon 22 communicates with the vacuum lumen 11 within the outer tube 42 through the distal outer tube opening 112. In some embodiments, a pressure relief valve 32 is provided in the vacuum pump body 31 to maintain vacuum in the vacuum lumen 11 and the void between the outer and inner balloons 21, 22. The right end of the pressure reducing valve 32 is communicated with the inner space of the vacuum pump body 31, is in the same pressure with the space of the vacuum pump body 31, and the left end of the pressure reducing valve is communicated with the inside of the operating handle 3 and is connected with the atmosphere. The opening of the pressure reducing valve 32 has a function of unidirectional control, when the pressure at the right end of the pressure reducing valve 32 exceeds a limit value, the pressure reducing valve 32 is opened to the left end and is discharged to the atmosphere, and the pressure reducing valve 32 cannot be opened to the right. When the pressure at the right end of the relief valve 32 is lower than the limit value, the relief valve 32 is in a closed state.

In some embodiments, vacuum pump body 31 is attached to vacuum tube 13, and the vacuum level that vacuum lumen 11 in the catheter body needs to reach during cryoablation is detected by vacuum tube 13. The control elements of the vacuum pump body 31 are electrically connected to a circuit board, the vacuum lumen 11 of the outer tube 42 communicates with the pressure reducing valve 32 and the vacuum tube 13 through the proximal outer tube opening 111, and the vacuum level in the vacuum lumen 11 and the gap between the outer balloon 21 and the inner balloon 22 is recorded by the circuit board. When the vacuum degree cannot meet the requirement, the pressure reducing valve 32 is used for one-way exhaust to realize the vacuum degree requirement; when the vacuum degree meets the requirement, the pressure reducing valve 32 is closed and cannot be opened so as to maintain the vacuum degree in the catheter main body, thereby realizing the regulation and monitoring of the vacuum degree, and the vacuum degree is always maintained in a certain range.

In some embodiments, the vacuum cavity 11 is attached to the inner wall of the outer tube 42, and 2 vacuum cavities 11 are symmetrically attached to the inner wall of the outer tube 42, uniformly distributed on the circumference of the outer tube 42, and one side of the vacuum cavity 11 is attached to the inner wall of the outer tube 42, and the other side is placed in the gap between the inner tube and the outer tube, see fig. 3.

The metal tube 44 is responsible for the delivery of the refrigerant, see fig. 2 and 11, and the end of the metal tube 44 is fixed on the inner tube 43 by winding, and a certain number of air outlet holes with certain aperture are uniformly distributed at the winding position. When the refrigerant reaches the end of the metal tube 44, the refrigerant is sprayed out from the air outlet holes, and the sprayed air is uniformly distributed at the front half part of the inner balloon 22 in a certain shape, so that the part has uniform refrigerating capacity, and the refrigerating capacity is uniformly transferred to human tissues through the outer balloon 21 which is abutted against the part. An inner tube 43 is located at the axial center of the inner balloon 22, and a metal tube 44 is on one side of the inner tube 43. As can be seen from the cross-sectional view at the maximum cross-section of the double-layered balloon (see fig. 4), the tube diameter of the metal tube 44 is very small relative to the size of the balloon, and the pressure difference between the interior of the metal tube 44 and the interior of the inner balloon 22 is very large. The refrigerant is input from the gas transmission cable at the left end of the fluid interface 33, is low-temperature liquid with pressure higher than atmospheric pressure, is conveyed to the tail end of the metal tube 44 of the freezing section through the metal tube in the conveying section, and is converted from liquid state to gas state at the tail end of the metal tube 44 due to the extremely large pressure difference change of the refrigerant, and is evaporated to absorb heat, so that heat of human tissues is taken away, and the treatment effect is achieved.

Referring to fig. 2, 5 and 6, the distal end of the inner tube 43 is fixed to the inner wall of the inner balloon 20, and the proximal end of the inner tube 43 communicates with the connector 34 on the operating handle 3. The inner tube 43 is wrapped by a protective sleeve from the connector 34 to the three-way joint 39 and then to the left side of the vacuum pump body 31. In some embodiments, saline may be injected into the connector 34, evacuating air from the inner tube 43, preventing air embolism during use, thereby compromising life; contrast media may also be injected from connector 34 prior to treatment, and visualization of the contrast media at the balloon tip may be used to determine the occlusion of the pulmonary vein ostium balloon, thereby adjusting the balloon position to ensure optimal abutment with the pulmonary vein ostium.

Referring to fig. 5 and 8-11, the operating handle 3 is further provided with a fluid interface 33, the fluid interface 33 is connected with a coaxial tube 35 in the operating handle 3 and the metal tube 44, and the coaxial tube 35 is sleeved on the outer side of the metal tube 44 in the axial direction. The left side of the fluid interface 33 is connected with a gas transmission cable, and the right side is connected with a coaxial tube 35. The refrigerant supplied from the fluid port 33 flows into the metal pipe 44 in the coaxial pipe 35, is supplied to the inner balloon 22 in the freezing section, is injected from the air outlet hole in the inner balloon 22, and is evaporated and cooled.

Referring to fig. 3, 8-11, the delivery catheter 4 further includes a gas recovery chamber formed by the gap between the outer tube 42 and the inner tube 43, and the gap between the coaxial tube 35 and the metal tube 44. In some embodiments, the axially outer portion of the metal tube 44 is sleeved with a built-in sleeve 45, and the gas recovery chamber is formed by the gap between the outer tube 42 and the inner tube 43, and the gap between the coaxial tube 35 and the built-in sleeve 45. The cryoablative gas is recovered through the gap between the outer tube 42 and the inner tube 43, the recovered gas enters the vacuum pump body 31 leftwards, passes through the protective sleeve of the inner tube, passes through the three-way joint 39, then enters the gap between the built-in sleeve 45 of the coaxial tube 35 and the coaxial tube 35, and finally is discharged from the gas transmission cable through the fluid interface 33. The built-in sleeve 45 is used for fixing the metal tube 44, has a certain heat preservation function, and reduces the refrigeration loss of the refrigerant in the metal tube in the coaxial tube section.

In some embodiments, referring to fig. 5, an optical sensor 36 is further provided in the operating handle 3, the optical sensor 36 is fixed on the coaxial tube 35, and the optical sensor 36 recognizes and alarms by detecting the color of blood. The optical sensor 36 may monitor the likelihood of human blood infiltration due to material rupture to determine whether an ablation procedure is being performed. When the cryoablation catheter is in normal operation, only recovered gas exists in the gap between the coaxial tube 35 and the metal tube 44, and when the materials are broken (including the materials such as the tank body of the conveying section 1 or the capsule body of the freezing section 2) to cause blood to permeate into the catheter system and further permeate into the coaxial tube 35, the color of the blood different from the gas can be monitored by the optical sensor 36, so that the abnormality of the system is prompted. For example, when the outer balloon 21 is ruptured, blood permeates into the vacuum lumen 11 from the ruptured portion, abnormality is recognized by the device optical sensor 36 and alarm is given, and then the cryoablation device can not perform cryoablation treatment any more, and the refrigerant does not enter the human body.

Referring to fig. 2, a thermocouple 23 is also provided within the cryoablation tube, the thermocouple 23 being disposed within the inner balloon 22 and secured to the metal tube 44. The thermocouple 23 can effectively detect the temperature change of the front half part of the balloon during cryoablation, and transmit data to the equipment interface in real time, so that an operator can conveniently judge the effectiveness of the cryoablation process.

Referring to fig. 5, the operating handle 3 is further provided with an electrical interface 37, the electrical interface 37 is in operative connection with a circuit board in the operating handle 3, the electrical interface 37 is used for connection with an external power source for supplying power to the thermocouple 23 and the circuit board in the conduit.

In some embodiments, a mapping catheter is disposed in the inner tube 43 with a mapping electrode at the end of the mapping catheter. The mapping electrode is used for measuring the pulmonary vein potential at the tail end of the saccule/the pulmonary vein port, so that the cryoablation effect is judged.

In some embodiments, referring to fig. 5 and 6, the inner tube 43 is connected to the push button 38, and the push button 38 is connected to the inner tube 43 by a section of spring. The push button 38 pushes forward or backward relative to the operating handle 3 to drive the inner tube 43 to advance or retreat, so as to adjust the axial straightening or compression of the double-layer capsule. When cryoablation begins, the axial length of the balloon is shortened due to the fact that the balloon is changed from a folded contracted state to an inflated state, the inner tube 43 is retracted a certain distance relative to the balloon at the moment of inflation, after cryoablation is finished, in order to enable the balloon to be fully tightly folded under the vacuumizing condition, a push button needs to be operated to extend the inner tube 43 so as to straighten the balloon, and then the balloon is tightened under vacuum so as to facilitate retraction of the balloon, and the phenomenon that the balloon is not clamped and retracted or difficult to retract due to insufficient folding or uneven folding of the balloon is prevented.

In some embodiments, referring to fig. 5 and 6, the operating handle 3 is further provided with a three-way joint 39, and the metal tube 44 forms a coil 441 after the central shaft 391 of the three-way joint 39 is wound one round; after the inner tube 43 and the metal tube 44 are intersected at the three-way joint 39, the inner tube 43 and the metal tube 44 are bonded together through the three-way joint 39 and then enter the vacuum pump body 31 forwards and enter the catheter body, and when the push button 38 is pushed forwards, the inner tube 43 bonded with the metal tube 44 cannot be pushed forwards because of the same length as the metal tube 44.

The circumference of the coil 441 varies by 3-8mm when it is tensioned to the diameter of the central shaft 391. The difference in axial length between the folded contracted and inflated conditions of the balloon is about 3-8mm, i.e., the push button 38 is moved back and forth over a distance of 3-8mm. After passing through the three-way joint 39, the inner tube 43 and the metal tube 44 are connected together by adhesion, the push button 38 drives the inner tube 43 to advance or retract, and the metal tube 44 is necessarily driven to advance or retract, if the metal tube 44 has no allowance in the axial length compared with the inner tube 43, the push button 38 cannot push the inner tube to advance, so that the metal tube 44 needs to leave allowance of 3-8mm to facilitate the pushing of the inner tube 43. The metal tube 44 has a margin in the axial length by the form of a coil, solving the problem of spatial arrangement of the metal tube 44. When the push button 38 is pushed to the forefront end, i.e. the inner tube 43 advances to the forefront end, the metal tube 44 is stretched forward, the winding 441 is pulled to the central shaft 391 fitting the three-way joint 39, and the change of the length of the metal tube 44 in the axial direction is converted into the change of the circumferential length, so that the placement of the metal tube 44 is facilitated, and the situation that the metal tube 44 is blocked or damaged due to irregular bending in the straightening or compressing process is prevented. The circumferential variation of the winding 441 when tightened to the diameter D of the central shaft 391 is 3-8mm, which is the same as the variation of the advancing or retreating of the inner tube 43 and the variation of the axial length of the balloon folding and contracting or inflating.

In some embodiments, referring to fig. 3, 5 and 6, the operating handle 3 is further provided with a knob 310. The knob 310 is wound with a stay wire 311, a stay wire inner cavity 421 is arranged in the outer tube 42, the stay wire 311 passes through the stay wire inner cavity 421, and the stay wire 311 extends forwards and is fixed at the tail end of the outer tube 42.

The distal end of the outer tube 42 is provided with a section of adjustable bending section 312, the distal end of the stay wire 311 is fixedly connected to the adjustable bending section 312, and the stay wire 311 is driven by rotating the knob 310, so that the adjustable bending section 312 bends left and right along the radial direction, and the balloon bends left and right along the radial direction.

The possible beneficial effects of the embodiment of the application include but are not limited to: (1) The surface of the balloon body of the double-layer balloon is coated with a film forming substance containing high heat conductivity filler, so that the refrigerant can be efficiently transferred to human tissues at low temperature of the balloon section, thereby achieving the purpose of rapidly cooling the tissues; (2) The film forming material has good flexibility, and under the inflation state, the saccule and the saccule can be fully attached to human tissues, so that the low-temperature high-efficiency conduction greatly reduces the treatment time and reduces the treatment cost; (3) The ablation catheter has the function of bending adjustment, and the advancing/retreating of the catheter is realized through ingenious transition of the length of the catheter from the axial direction to the circumferential direction, so that the folding compression/inflation expansion state of the balloon is effectively realized; (4) The integrity of the ablation catheter can be detected while the liquefied refrigerant is transported, and the vacuum level between the inner balloon and the outer balloon and whether blood enters the catheter system can be monitored and adjusted in real time.

While the basic concepts have been described above, it will be apparent to those skilled in the art that the foregoing detailed disclosure is by way of example only and is not intended to be limiting. Although not explicitly described herein, various modifications, improvements, and adaptations to the present disclosure may occur to one skilled in the art. Such modifications, improvements, and modifications are intended to be suggested within this specification, and therefore, such modifications, improvements, and modifications are intended to be included within the spirit and scope of the exemplary embodiments of the present application.

Meanwhile, the specification uses specific words to describe the embodiments of the specification. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the present description. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the present description may be combined as suitable.

Furthermore, the order in which the elements and sequences are processed, the use of numerical letters, or other designations in the description are not intended to limit the order in which the processes and methods of the description are performed unless explicitly recited in the claims. While certain presently useful inventive embodiments have been discussed in the foregoing disclosure, by way of various examples, it is to be understood that such details are merely illustrative and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements included within the spirit and scope of the embodiments of the present disclosure. For example, while the system components described above may be implemented by hardware devices, they may also be implemented solely by software solutions, such as installing the described system on an existing server or mobile device.

Likewise, it should be noted that in order to simplify the presentation disclosed in this specification and thereby aid in understanding one or more inventive embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof. This method of disclosure, however, is not intended to imply that more features than are presented in the claims are required for the present description. Indeed, less than all of the features of a single embodiment disclosed above.

In some embodiments, numbers describing the components, number of attributes are used, it being understood that such numbers being used in the description of embodiments are modified in some examples by the modifier "about," approximately, "or" substantially. Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number allows for a 20% variation. Accordingly, in some embodiments, numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and employ a method for preserving the general number of digits. Although the numerical ranges and parameters set forth herein are approximations that may be employed in some embodiments to confirm the breadth of the range, in particular embodiments, the setting of such numerical values is as precise as possible.

Each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., referred to in this specification is incorporated herein by reference in its entirety. Except for application history documents that are inconsistent or conflicting with the content of this specification, documents that are currently or later attached to this specification in which the broadest scope of the claims to this specification is limited are also. It is noted that, if the description, definition, and/or use of a term in an attached material in this specification does not conform to or conflict with what is described in this specification, the description, definition, and/or use of the term in this specification controls.

Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments of this specification. Other variations are possible within the scope of this description. Thus, by way of example, and not limitation, alternative configurations of embodiments of the present specification may be considered as consistent with the teachings of the present specification. Accordingly, the embodiments of the present specification are not limited to only the embodiments explicitly described and depicted in the present specification.

Claims (18)

1. A cryoablation tube comprising a delivery segment and a cryosegment, the delivery segment comprising an operating handle and a delivery catheter; the delivery catheter has a distal end and a proximal end; the freezing section is connected with the distal end of the conveying catheter, and the operating handle is connected with the proximal end of the conveying catheter, and is characterized in that:

the freezing section comprises a contractible and expandable double-layer bag body, and the surface of a bag film of the double-layer bag body is coated with a polymer film containing high thermal conductivity filler; the double-layer balloon body consists of an outer balloon and an inner balloon arranged in the outer balloon;

a vacuum pump body is arranged in the operating handle;

a vacuum cavity is arranged in the conveying catheter, and a gap between the outer balloon and the inner balloon is communicated with the vacuum pump through the vacuum cavity;

the film forming material of the polymer film comprises polyurethane or polysiloxane and high thermal conductivity filler, and the solution of the film forming material is sprayed into fine mist drops in a vacuum chamber to be deposited on the surfaces of the inner balloon and the outer balloon to form the polymer film.

2. The cryoablation tube of claim 1 wherein: the polymer film contains 5-15% of high thermal conductivity filler.

3. The cryoablation tube of claim 2 wherein: the high thermal conductivity filler comprises a graphene material or a carbon fiber material.

4. The cryoablation tube of claim 1 wherein: the vacuum pump body is internally provided with a pressure reducing valve, one end of the pressure reducing valve is opened and communicated with the internal space of the vacuum pump body, and the other end of the pressure reducing valve is led into the operating handle.

5. The cryoablation tube of claim 4 wherein: the pressure reducing valve is a one-way valve, and the opening direction of the one-way valve is the inside of the operating handle.

6. The cryoablation tube of claim 5 wherein: the vacuum pump body is connected with a vacuum tube.

7. The cryoablation tube of claim 1 wherein: the conveying conduit comprises a conduit body, and an outer tube, an inner tube and a metal tube which are arranged in the conduit body.

8. The cryoablation tube of claim 7 wherein: the vacuum inner cavity is attached to the inner wall of the outer tube.

9. The cryoablation tube of claim 7 wherein: the distal end of the inner tube is fixed on the inner wall of the inner balloon, and the proximal end of the inner tube is communicated with a connector on the operating handle.

10. The cryoablation tube of claim 9 wherein: the inner tube is connected with a push button, and the push button is pushed forward or backward relative to the operating handle to drive the inner tube to advance or retreat, so as to adjust the axial extension or compression of the double-layer bag body.

11. The cryoablation tube of claim 10 wherein: the push button is connected with the inner tube through a section of spring.

12. The cryoablation tube of claim 11 wherein: the operating handle is also provided with a three-way joint, and the metal pipe forms a winding after the middle shaft of the three-way joint winds one circle; the inner tube and the metal tube enter the vacuum pump body and then enter the catheter main body after being intersected at the three-way joint.

13. The cryoablation tube of claim 12 wherein: the circumference variation of the coil when being tensioned to the diameter of the central shaft is 3-8mm.

14. The cryoablation tube of claim 7 wherein: the operation handle is also provided with a knob, the knob is wound with a stay wire, and the stay wire is fixed at the tail end of the outer tube in a forward extending way through the inner cavity of the outer tube.

15. The cryoablation tube of claim 14 wherein: the distal end of the outer tube is provided with an adjustable bending section, the distal end of the stay wire is fixedly connected with the adjustable bending section, and the stay wire is driven by rotating the knob.

16. The cryoablation tube of claim 7 wherein: the operating handle is also provided with a fluid interface, the fluid interface is connected with a coaxial tube in the operating handle and the metal tube, and the coaxial tube is sleeved on the outer axial side of the metal tube.

17. The cryoablation tube of claim 16 wherein: an optical sensor is further arranged in the operating handle, and the optical sensor is fixed on the coaxial tube.

18. The cryoablation tube of claim 16 wherein: the delivery catheter further includes a gas recovery lumen formed by the gap between the outer tube and the inner tube, the gap between the coaxial tube and the metal tube.