Fluid ejection device and cryoballoon

Abstract

The application provides a fluid injection device and a frozen balloon, the fluid injection device comprising a connecting fluid channel, which is provided with a connecting channel inlet and a connecting channel outlet, the connecting channel inlet is communicated with an external liquid supply device, and the connecting fluid channel is provided in a hollow tubular structure; an annular fluid channel is arranged at one end of the connecting fluid channel, the annular fluid channel is provided with a plurality of annular channel inlets and a plurality of injection ports, the plurality of annular channel inlets are connected one by one with the plurality of connecting channel outlets, the plurality of injection ports are arranged at intervals along the circumference of the annular fluid channel, and the axis of the annular fluid channel is collinear with the axis of the tubular structure. Liquid enters through the connecting fluid channel inlet, is divided into a plurality of streams of fluid through the connecting fluid channel and enters the annular fluid channel through the plurality of annular channel inlets. Since the annular fluid channel is a circular ring structure, the fluid can flow symmetrically and uniformly under the action of the annular fluid channel, thereby reducing or avoiding the generation of turbulent flow.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a fluid jetting device and a cryoballoon. Background Technology

[0002] Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice. It is estimated that more than 33 million people worldwide suffer from AF. According to data published in China in 2004, the prevalence of AF among residents aged 30 to 85 was 0.77%, with a prevalence exceeding 30% in those over 80 years of age. The incidence of AF increases with age. Compared to non-AF patients of the same age, AF patients often have a poorer quality of life and frequently suffer from hypertension, heart failure, and other complications, resulting in higher rates of thromboembolic complications and mortality. Recent studies have linked AF to the development of dementia. Therefore, effective treatment of AF has significant clinical importance. In long-term follow-up care, interventions to control AF have been shown to improve quality of life.

[0003] For patients with paroxysmal atrial fibrillation, cryoballoon ablation offers a high level of safety: the tissue damage lesions created by cryoablation are more uniform and have clearer boundaries, and do not cause eschar, vaporization, or collagen degeneration and contracture associated with high-temperature effects, thus preserving the integrity of tissue cells to the greatest extent. Theoretically, this can reduce the risk of serious complications such as thrombosis, pulmonary vein stenosis, cardiac perforation, and atrial-esophageal fistula. During cryoablation, the balloon catheter adheres to the ablated tissue with minimal catheter displacement, improving ablation safety. Before deep cryoablation, the cryogenic energy can cause transient and reversible damage to the tissue, significantly reducing the risk of permanent damage to important tissues.

[0004] Conventional ablation devices employ a cascade cooling system, using nitrogen (N2O) as the cryoablation medium. This medium travels through the device's sophisticated tubing, passing through a coaxial fluid connector and catheter body, to reach the distal balloon. Inside the balloon, the cryo-N2O absorbs heat through a phase-change evaporation effect, reaching a cryoablation temperature sufficient to induce myocardial tissue necrosis, thus achieving cooling and ablation. The vapor, after heat exchange with the myocardium, returns to the cryoablation device via the catheter body and coaxial fluid connector. A vacuum pump maintains a vacuum environment inside the device, and the vapor is ultimately discharged into the hospital's waste gas system.

[0005] The cryoablation balloon catheter is connected to a cryoablation device for cryoablation treatment of myocardial tissue. The spherical balloon is positioned against the pulmonary vein opening in the left atrium. The cryogenic working fluid is injected through multiple nozzles inside the balloon, vaporizing, expanding, and cooling. The cooling area forms a ring, largely coinciding with the target treatment site in the myocardium, resulting in more concentrated cryoablation energy delivery, lower cooling loss, and reduced risk of cryoablation complications. The balloon has a built-in temperature sensor to monitor the treatment temperature in real time, and the catheter handle has built-in pressure and optical sensors to monitor balloon integrity in real time, preventing cryogenic working fluid leakage into the bloodstream. The catheter tip is bidirectionally flexible, allowing it to be positioned against the target treatment site within the heart.

[0006] The existing technical solution: Existing cryoballoon catheters generally include a slender tubular main tube. A matching instrument (e.g., a guidewire or mapping catheter) is slidably fitted inside the main tube. An inner balloon and an outer balloon are sequentially fitted around the main tube. The distal ends of the inner and outer balloons form a double-layered cryoballoon, which is tightly sealed together by vacuum. When the inner balloon is gradually filled with a refrigerant fluid (e.g., liquid nitrous oxide, N2O), the cryoballoon takes on an approximately ellipsoidal shape. A temperature sensor, fixedly connected to the main tube, is installed inside the cryoballoon to measure temperature changes within it.

[0007] The main body of the injection device is a hollow tube (typically nickel-titanium or polyimide) with a closed blind end at the distal end. This main body extends along the axis of the main tube, with the refrigerant fluid inlet at its proximal end and the distal end forming a spiral structure fixedly assembled with the main tube. Injection holes are formed on the outermost circumference of the spiral structure. When the cryoballoon needs inflation, the refrigerant fluid enters from the proximal end of the injection device, flows to the distal end, and is ejected from the injection holes towards the distal hemisphere of the cryoballoon for cryoablation. In actual use, the first injection hole has the worst refrigerant injection state and the lowest flow rate, while the second injection hole has the best refrigerant injection state and the highest flow rate.

[0008] According to Bernoulli's principle, the total pressure of an ideal fluid equals the dynamic pressure plus the static pressure plus gravitational potential energy, and the total pressure remains constant throughout the pipe. Constraints: the fluid is incompressible; the sum of the cross-sectional areas of all injection holes is less than the cross-sectional area of ​​the hollow tube; the pressure of the refrigerant flowing into the hollow tube is sufficiently high; and the flow resistance of the inner wall of the hollow tube is negligible. Assuming zero gravitational potential energy and approximately equal total pressure throughout the spiral section of the hollow tube, the refrigerant inside the hollow tube exhibits the fastest flow velocity, highest dynamic pressure, and lowest static pressure at the first injection hole, and the slowest flow velocity, lowest dynamic pressure, and highest static pressure at the second injection hole.

[0009] The factor determining the injection state / flow rate of the injection orifice is the static pressure difference inside and outside the injection orifice. When the static pressure outside the injection orifice remains constant, the higher the static pressure inside the injection orifice, the better the injection state and the greater the flow rate; conversely, the lower the static pressure inside the injection orifice, the better the injection state and the greater the flow rate. Therefore, the first injection orifice has the worst refrigerant injection state and the smallest flow rate, while the second injection orifice has the best refrigerant injection state and the largest flow rate.

[0010] Therefore, in practical applications, to ensure that the cooling capacity along the circumferential direction of the distal surface of the cryosphere is approximately uniform and to mitigate the negative impact of inconsistent spray patterns, the arrangement of orifices 1-N needs to be adjusted as follows (taking 8 orifices as an example): each orifice is spaced 135 degrees apart along the spiral circumference, so that the orifices are evenly distributed with a 45-degree interval in the axial projection direction of the main tube. Furthermore, in the axial projection direction of the main tube, orifices with better and worse spray patterns are arranged alternately to improve the uneven distribution of refrigerant spray caused by flow rate differences.

[0011] Existing technology alternates between orifices with good and poor spray patterns, but it still cannot achieve absolute uniformity in spray pattern. For example, the spray pattern of the first and fourth orifices is necessarily worse than that of the fifth and eighth orifices.

[0012] Taking eight small holes as an example, when the holes are arranged at 135-degree intervals (or, in other words, as long as the hole spacing is an odd multiple of 45 degrees, such as 1, 3, 5, 7...), the eight holes will be located in different cross-sections of the spiral. The larger the multiple, the farther the distance between the cross-section of the first hole and the cross-section of the eighth hole. In other words, the eight holes cannot fall in the same plane perpendicular to the main tube.

[0013] After the refrigerant is ejected from the orifice, the distance from the orifice to the balloon surface varies significantly due to the different cross-sections of the spiral path. If the refrigerant vaporizes and expands upon reaching the balloon surface, it is considered effective cooling. If the refrigerant partially or completely vaporizes before reaching the surface, it is considered inefficient or ineffective cooling. The farther the orifice is from the balloon surface, the more likely it is to vaporize and expand before reaching the surface, resulting in inefficient or ineffective cooling. The orifice with the worst ejection state is furthest from the balloon surface, while the orifice with the best ejection state is closest, which further exacerbates the problem of uneven cooling on the distal surface of the balloon. Summary of the Invention

[0014] In view of this, the present invention provides a fluid jetting device and a cryosphere to reduce the impact of fluid turbulence generated during the flow of refrigerant.

[0015] The embodiments of this specification provide the following technical solution: a fluid jetting device, comprising: a connecting fluid channel having a connecting channel inlet and a connecting channel outlet, the connecting channel inlet being connected to an external liquid supply device, and the connecting fluid channel being configured as a hollow tubular structure; an annular fluid channel being disposed at one end of the connecting fluid channel, the annular fluid channel having multiple annular channel inlets and multiple nozzles, the multiple annular channel inlets being connected one-to-one with the multiple connecting channel outlets, the multiple nozzles being arranged at intervals along the circumference of the annular fluid channel, and the axis of the annular fluid channel being collinear with the axis of the tubular structure.

[0016] Furthermore, the annular channel has at least three inlets and at least three nozzles.

[0017] Furthermore, each annular channel entrance is located between two adjacent annular channel exits.

[0018] Furthermore, the sum of the cross-sectional areas of the multiple nozzles is less than the cross-sectional area of ​​the connecting channel inlet.

[0019] Furthermore, the fluid injection device also includes a cylinder, on which both the connecting fluid channel and the annular fluid channel are disposed.

[0020] Furthermore, the cylinder has an annular radial cross section, and both the connecting fluid channel and the annular fluid channel are located inside the cylinder wall; or, the cylinder has a circular radial cross section, and both the connecting fluid channel and the annular fluid channel are fixed outside the cylinder wall.

[0021] Furthermore, the axis of each nozzle is located within the radial section of the same annular fluid channel.

[0022] Furthermore, the connecting fluid channels are axially symmetrical with respect to the axis of the cylinder; or, the connecting fluid channels are mirror-symmetrical with respect to the axial section of the cylinder; or, the connecting fluid channels are spirally distributed with respect to the axis of the cylinder.

[0023] Furthermore, the nozzles are axially symmetrical with respect to the axis of the cylinder or mirror symmetrical with respect to the axial section of the cylinder.

[0024] The present invention also provides a cryoballoon, including the above-described fluid injection device.

[0025] Compared with the prior art, the beneficial effects that can be achieved by the above-mentioned at least one technical solution adopted in the embodiments of this specification include at least the following: the liquid enters through the inlet of the connecting fluid channel, is divided into multiple streams of fluid through the connecting fluid channel, and enters the annular fluid channel through multiple annular channel inlets. Since the annular fluid channel is a circular structure, the fluid can flow symmetrically and uniformly under the action of the annular fluid channel, thereby reducing or avoiding the generation of turbulence. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the pipeline distribution in the first embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the pipeline distribution from a first-view perspective in the second embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the pipeline distribution from a second perspective in the second embodiment of the present invention;

[0030] Figure 4 This is a three-dimensional structural schematic diagram of the cylinder in the second embodiment of the present invention;

[0031] Figure 5 This is a simulation diagram of the pressure distribution in an 8-hole structure using existing technology.

[0032] Figure 6 This is a simulation diagram of the pressure distribution in an 8-hole configuration according to an embodiment of the present invention.

[0033] In the figure, the reference numerals are: 10, connecting fluid channel; 20, annular fluid channel; 30, cylinder. Detailed Implementation

[0034] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] like Figures 1 to 4 As shown, this embodiment of the invention provides a fluid jetting device, including a connecting fluid channel 10 and an annular fluid channel 20. The connecting fluid channel 10 is provided with a connecting channel inlet and a connecting channel outlet. The connecting channel inlet is connected to an external liquid supply device, and the connecting fluid channel 10 is arranged in a hollow tubular structure. The annular fluid channel 20 is located at one end of the connecting fluid channel 10. The annular fluid channel 20 is provided with multiple annular channel inlets and multiple nozzles. The multiple annular channel inlets are connected to the multiple connecting channel outlets one by one. The multiple nozzles are arranged at intervals along the circumference of the annular fluid channel 20, and the axis of the annular fluid channel 20 is collinear with the axis of the tubular structure formed by the connecting fluid channel 10.

[0037] The liquid enters through the inlet of the connecting fluid channel 10, is divided into multiple streams of fluid through the connecting fluid channel 10, and enters the annular fluid channel 20 through multiple annular channel inlets. Since the annular fluid channel 20 has a circular structure, the fluid can flow symmetrically and uniformly under the action of the annular fluid channel 20, thereby reducing or avoiding the generation of turbulence.

[0038] It should be noted that the connecting fluid channel 10 is axially symmetrical with respect to the axis of the annular fluid channel 20; or, the connecting fluid channel 10 is mirror symmetrical with respect to the axial section of the annular fluid channel 20; or, the connecting fluid channel 10 is spirally distributed with respect to the axis of the annular fluid channel 20.

[0039] Each annular channel inlet is located between two adjacent annular channel outlets. The sum of the cross-sectional areas of the multiple nozzles (all nozzles) is less than the cross-sectional area of ​​the connecting channel inlets.

[0040] The annular channel inlets are all located between two adjacent annular channel outlets, which allows the fluid to flow evenly toward the nozzles on both sides when it enters the annular fluid channel 20 from the annular channel inlet, thus avoiding the problem of uneven spraying caused by the different distances between the annular channel inlet and the nozzles on both sides.

[0041] Simultaneously, the sum of the cross-sectional areas of multiple nozzles (all nozzles) being less than the cross-sectional area of ​​the connecting channel inlet helps avoid fluid turbulence. When the refrigerant is injected unevenly, the ablation energy received by the tissue in contact with the surface of the cryoballoon (e.g., the pulmonary vein orifice) is also uneven. In this case, after the cryoballoon ablates the tissue (e.g., the pulmonary vein orifice), the ablation result will also be uneven; for example, some tissues may be over-ablated while others are not, or even leaks may occur during ablation. Over-ablation may damage the esophagus, phrenic nerve, or even the brain. Incomplete ablation will result in poor electrical isolation of the tissue, failing to achieve the expected ablation purpose. This not only reduces the effectiveness of cryoablation but also increases the recurrence rate after atrial fibrillation treatment. This application can effectively solve the problem of uneven refrigerant injection, thereby effectively improving the uniformity of cryoablation, improving the effectiveness of cryoablation, and reducing the recurrence rate of treatment.

[0042] The annular channel inlets have at least three, and the nozzles have at least three. In this embodiment, the number of nozzles is generally 8-16, preferably 8, 12, or 16. The corresponding number of annular channel inlets can be half the number of nozzles, i.e., 4-8, preferably 4, 6, or 8. The specific numbers mentioned above do not limit this application; this application can provide different numbers of annular channel inlets and nozzles depending on different working conditions.

[0043] The fluid jetting device also includes a cylinder 30, on which the connecting fluid channel 10 and the annular fluid channel 20 are both disposed.

[0044] In one embodiment, the cylinder 30 has an annular radial cross section, and the connecting fluid channel 10 and the annular fluid channel 20 are embedded inside the pipe wall of the cylinder 30. The cylinder 30 has a sleeve-like structure with open ends, and the aforementioned connecting fluid channel 10 and annular fluid channel 20 are located between the inner and outer pipe walls of the cylinder 30, with the nozzle connected to the outer side.

[0045] In another embodiment, the cylinder 30 has a circular radial cross section, and the connecting fluid channel 10 and the annular fluid channel 20 are fixed to the outside of the pipe wall of the cylinder 30; that is, the connecting fluid channel 10 and the annular fluid channel 20 are solid pipelines, fixedly arranged along the outer periphery of the cylinder 30, and the nozzle is arranged on the outer surface of the fluid channel.

[0046] Preferably, the nozzles are axially symmetrical with respect to the axis of the cylinder 30 or mirror-symmetrical with respect to the axial section of the cylinder 30. Each nozzle includes at least one radial injection hole or at least one radial injection slit.

[0047] Setting nozzles allows the refrigerant in the annular fluid channel 20 to be uniformly sprayed to a set position. The number and structure of the nozzles in this embodiment can be selected according to different needs.

[0048] Specifically, in this embodiment of the invention, the axis of each nozzle is located within the radial section of the same annular fluid channel 20. Furthermore, the inlet axis of the annular channel is parallel to the axis of the annular fluid channel 20, and the axis of each nozzle is parallel to the radial direction of the annular fluid channel 20.

[0049] In other embodiments of the present invention, there is an angle between the axis of the annular channel inlet and the axis of the annular fluid channel 20, and there is also an angle between the axis of the nozzle and the axis of the annular channel inlet, and the angle is greater than or equal to 90° and less than or equal to 180°.

[0050] When the included angle is 90°, the injection demand of the balloon is optimal because the axis of the annular channel inlet is perpendicular to the axis of the annular fluid channel 20. When the included angle is 180°, the turbulence generated in the annular fluid channel 20 is minimized because the axis of the annular channel inlet is parallel to the axis of the annular fluid channel 20.

[0051] The connecting fluid channels 10 are axially symmetrical with respect to the axis of the cylinder 30; or, the connecting fluid channels 10 are mirror symmetrical with respect to the axial section of the cylinder 30; or, the connecting fluid channels 10 are spirally distributed with respect to the axis of the cylinder 30.

[0052] Specifically, the connecting fluid channel 10 includes at least one first branch unit; when the connecting fluid channel 10 includes one first branch unit, the first branch unit is mirror-symmetric with respect to the axial section of the cylinder 30; or, when the connecting fluid channel 10 includes at least two first branch units, each first branch unit is rotationally symmetric with respect to the axis of the cylinder 30. Each first branch unit is provided with a first main path and a first branch path. The inlet of the first branch path is located in the middle of the first branch path, and the outlet of the first branch path is located at both ends of the first branch path. The outlets of the two first branch paths are centrally or axially symmetric with respect to the first main path. The outlet of the first main path is connected to the inlet of the first branch path, and the extension direction of the first main path is parallel to the axis of the cylinder 30. The nozzle includes two radial injection holes. The cross-sectional area of ​​the radial injection holes is less than or equal to the cross-sectional area of ​​the first branch path, and the cross-sectional area of ​​the first main path is greater than or equal to twice the cross-sectional area of ​​the first branch path. In a preferred embodiment, the cross-sectional area of ​​the radial injection holes is approximately equal to the cross-sectional area of ​​the first branch path, and the cross-sectional area of ​​the first main path is greater than or equal to twice the cross-sectional area of ​​the first branch path.

[0053] It should be noted that in this embodiment of the invention, the extension direction of the first main path is parallel to the axial direction of the cylinder 30, that is, the overall shape of the first branch unit can be T-shaped or Y-shaped (axisymmetric figure). Alternatively, the shape of the first branch path can be S-shaped, with the outlet of the first main path connected to the center of the S-shape (centrally symmetrical figure).

[0054] The present invention also has the following embodiments: the first branch can be two, the two first branches form an X-shaped structure, the first main road is a straight pipeline, and the outlet of the first main road is connected to the center of the X-shaped structure. Alternatively, the first branch can be two, both ends of the first main road are outlets, the middle of the first main road is an inlet, and each end of the first main road outlet is connected to a corresponding first branch, that is, the overall shape of the first branch unit is I-shaped.

[0055] Of course, in different embodiments, the first main route can also be a curved pipeline, and the above embodiments can also be combined with each other.

[0056] The fluid channel in this embodiment of the invention includes a second branch unit, which includes a second main channel and a second branch. The inlet of the second branch is located in the middle of the second branch, and the outlet of the second branch is located at both ends of the second branch. The outlets of the two second branches are centrally or axially symmetrically distributed with respect to the second main channel. The outlet of the second main channel is connected to the inlet of the second branch. The extension direction of the second main channel is parallel to the axis of the cylinder 30. The outlets of the two second branches are connected to the two first branch units one by one.

[0057] The cross-sectional area of ​​the second branch road is greater than or equal to the cross-sectional area of ​​the first main road, and the cross-sectional area of ​​the second main road is greater than or equal to twice the cross-sectional area of ​​the second branch road. In a preferred embodiment, the cross-sectional area of ​​the second branch road is approximately equal to the cross-sectional area of ​​the first main road, and the cross-sectional area of ​​the second main road is greater than or equal to twice the cross-sectional area of ​​the second branch road.

[0058] The structure of the second main path and the second branch path can adopt the structure of the first branch unit in the above embodiments, such as a T-shape or a Y-shape. The pipe diameter in the second branch unit should be greater than or equal to the pipe diameter of the first branch unit, so as to ensure that the fluid velocity and the injection pressure of the radial injection hole in the subsequent branch unit can reach the set value.

[0059] In another embodiment of the present invention, the outlet of each second branch is connected to the first fluid inlet of the two first branch units, and the two first branch units connected to the outlet of the same second branch are axially symmetrical with respect to the corresponding second branch.

[0060] In this embodiment, at least two second branch units are evenly distributed along the circumferential distance of the cylinder 30, and the flow velocity and flow rate of the fluid inlet of each second branch unit are the same, thereby ensuring that the inlet flow velocity and flow rate of each second branch unit are the same.

[0061] More preferably, the fluid injection device further includes a third branch unit, which includes a third main road and a third branch. The inlet of the third branch is located in the middle of the third branch, and the outlet of the third branch is located at both ends of the third branch. The outlets of the two third branches are centrally symmetrical or axially symmetrical with respect to the third main road. The outlet of the third main road is connected to the inlet of the third branch. The extension direction of the third main road is parallel to the axis of the cylinder 30. The outlets of the two third branches are connected one-to-one with the second fluid inlets of the two second branch units.

[0062] There are at least two third branch units, and these at least two third branch units are evenly distributed circumferentially along the cylinder 30. The cross-sectional area of ​​the third branch is greater than or equal to the cross-sectional area of ​​the second main branch, and the cross-sectional area of ​​the third main branch is greater than or equal to twice the cross-sectional area of ​​the third branch. In a preferred embodiment, the cross-sectional area of ​​the third branch is approximately equal to the cross-sectional area of ​​the second main branch, and the cross-sectional area of ​​the third main branch is greater than or equal to twice the cross-sectional area of ​​the third branch.

[0063] It should be noted that the first, second, and third branches mentioned above can all be straight or curved pipelines.

[0064] For example, in this embodiment of the invention, the first and second branches are straight branches, and the third branch is a curved pipeline. The third branch includes two parallel, spaced-apart straight segments and a connecting segment, with both ends of the connecting segment connected to the same end of the two straight segments. The purpose of configuring the third branch in this structure is to reduce the influence of the third branch on the dynamic and static pressure of the refrigerant, thereby achieving the intended purpose.

[0065] The first branch, the second branch, and the third branch can adopt the same structure or a combination of different structures, as long as they can meet the limitation of the same flow resistance in the above embodiments.

[0066] In embodiments not illustrated in this application, the first branch, the second branch, and the third branch can be regarded as a tree-shaped branch unit. Different numbers of tree-shaped branch units can be set according to the number of nozzles, which will not be described in detail here.

[0067] It should be noted that the cylindrical body 30 in this embodiment of the invention can be integrally formed using 3D printing technology, or it can be a split structure. The split-structure cylindrical body 30 includes an inner cylinder and an outer cylinder. The outer wall of the inner cylinder is provided with groove-shaped first branch units, second branch units, and third branch units as described above. Their distribution is the same as in the above embodiment, and will not be repeated here. The near-end and far-end faces of the inner and outer cylinders are welded or bonded together, and corresponding positioning grooves are provided for positioning.

[0068] This invention also provides a cryoballoon, including the fluid injection device described above. The cryoballoon catheter includes a main tube and a fluid tube, the main tube being inserted into the inner hole of the cylindrical body 30 or the hollow portion of the cylindrical structure.

[0069] In this embodiment, the fluid jetting device can be sleeved on the outside of the main tube. The fluid jetting device and the main tube can be connected by welding, bonding or other fixed connection methods, or the fluid jetting device can be configured to slide relative to the main tube.

[0070] Alternatively, a limiting part can be set on the main tube so that when the fluid jetting device is inserted into the main tube, it can engage with the limiting part to limit the axial displacement of the fluid jetting device.

[0071] The aforementioned fluid pipe is used to provide refrigerant to the fluid injection device. In this embodiment of the invention, the number of fluid pipes is at least one, but multiple pipes can be selected according to different needs, and the flow rate of each fluid pipe should be the same.

[0072] like Figure 5 and Figure 6 As shown, the pressure distribution of the existing 8-hole system is illustrated in the figure. Figure 5 As can be seen, the pressure distribution is not uniform. For the 8-hole pressure distribution of this application, please refer to [reference needed]. Figure 6 It is evident that the pressure distribution of this application is much more uniform than that of the prior art. Compared with the prior art, this application has the following beneficial effects in terms of pressure distribution: This application can avoid uneven cryoablation effect of tissue due to uneven pressure distribution, or even the generation of ablation leaks, resulting in poor tissue potential isolation effect, thereby reducing the effectiveness of cryoablation and causing a high recurrence rate of atrial fibrillation after treatment.

[0073] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical solutions, and technical solutions in this invention can be freely combined and used.

Claims

1. A fluid jetting device, characterized in that, include: The connecting fluid channel (10) is provided with a connecting channel inlet and a connecting channel outlet. The connecting channel inlet is connected to an external liquid supply device, and the connecting fluid channel (10) is enclosed in a hollow tubular structure. An annular fluid channel (20) is provided at one end of the connecting fluid channel (10). The annular fluid channel (20) is provided with multiple annular channel inlets and multiple nozzles. The multiple annular channel inlets are connected to the multiple connecting channel outlets one by one. The multiple nozzles are arranged at intervals along the circumference of the annular fluid channel (20), and the axis of the annular fluid channel (20) is collinear with the axis of the tubular structure. Each annular channel inlet is provided between two adjacent annular channel outlets. The cylinder (30), the connecting fluid channel (10) and the annular fluid channel (20) are all provided on the cylinder (30).

2. The fluid jetting device according to claim 1, characterized in that, The annular channel has at least three inlets, and the nozzles have at least three outlets.

3. The fluid jetting device according to claim 1, characterized in that, The sum of the cross-sectional areas of the plurality of nozzles is less than the cross-sectional area of ​​the inlet of the connecting channel.

4. The fluid jetting device according to claim 1, characterized in that, The cylinder (30) has a circular radial cross section, and the connecting fluid channel (10) and the annular fluid channel (20) are both located inside the pipe wall of the cylinder (30); or, the cylinder (30) has a circular radial cross section, and the connecting fluid channel (10) and the annular fluid channel (20) are both fixed outside the pipe wall of the cylinder (30).

5. The fluid jetting device according to claim 1, characterized in that, The axis of each of the nozzles is located within the radial section of the same annular fluid channel (20).

6. The fluid jetting device according to claim 1, characterized in that, The connecting fluid channels (10) are axially symmetrical with respect to the axis of the cylinder (30); or the connecting fluid channels (10) are mirror symmetrical with respect to the axial section of the cylinder (30); or the connecting fluid channels (10) are spirally distributed with respect to the axis of the cylinder (30).

7. The fluid jetting device according to claim 1, characterized in that, The nozzles are axially symmetrical with respect to the axis of the cylinder (30) or mirror symmetrical with respect to the axial section of the cylinder (30).

8. A cryoballoon, comprising a fluid injection device, characterized in that, The fluid jetting device is the fluid jetting device according to any one of claims 1 to 7.

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