Cryogenic ablation catheter and device

Abstract

The application relates to a cryoablation catheter and device, the cryoablation catheter comprising a smoothing mechanism, the smoothing mechanism comprising at least one pressing plate, the pressing plate being slidably arranged at the distal end of a catheter body along the axial direction of the catheter body, wherein, in response to the switching of a balloon from a contracted state to a filled state, the pressing plate is expanded along the radial direction of the catheter body and moves along the catheter body from the distal end to the proximal end, and in response to the switching of the balloon from the filled state to the contracted state, the pressing plate is contracted along the radial direction of the catheter body and moves along the catheter body from the proximal end to the distal end while keeping abutting to the outer wall of the balloon. The cryoablation catheter provided by the application can smooth the bulges / folds on the surface of the balloon when the balloon is switched from the filled state to the contracted state, prevent the occurrence of adverse phenomena such as bulges / folds on the surface of the contracted balloon, keep the size of the balloon as a smaller value, and smoothly retract the balloon into the guide catheter, so that the cryoablation catheter is conveniently withdrawn to the outside of the patient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a cryoablation catheter and device. BACKGROUND

[0002] Cryoablation based on catheter intervention is a common treatment method. For example, cryoablation can be used to ablate the pulmonary vein antrum, resulting in pulmonary vein electrical isolation, thereby treating atrial fibrillation.

[0003] During these cryoablation treatments, a cryoablation balloon is pushed to the target area through the guide catheter along the body lumen, and the balloon is expanded to deliver a refrigerant for ablation. After ablation is complete, the refrigerant in the balloon needs to be discharged, and the balloon is contracted and then recovered into the guide catheter and withdrawn from the body.

[0004] After the pulmonary vein ablation balloon is expanded, it is usually spherical in shape to facilitate the occlusion of the pulmonary vein antrum during pulmonary vein ablation. After ablation is complete, the ideal state of the contracted balloon is that the balloon is in a straight state and the balloon wall is folded together, which helps the recovery into the guide catheter. However, in the prior art, the spherical balloon is difficult to form a regular wing-shaped fold after contraction, and is usually stacked near the equator of the spherical balloon, forming a large protrusion, which will accumulate at the mouth of the guide catheter during recovery, causing the balloon to be unable to be smoothly withdrawn from the body, and in severe cases, the balloon may even rupture or fall off, etc. SUMMARY

[0005] Therefore, it is necessary to provide a cryoablation catheter and device to solve the problem that the balloon wall of the cryoablation balloon will form a bulge / crease and accumulate at the mouth of the guide catheter during the contraction process.

[0006] A cryoablation catheter, comprising a catheter body and a balloon connected to the catheter body, the catheter body having opposite distal and proximal ends in the axial direction thereof, the catheter body having a fluid channel in communication with the inner cavity of the balloon, the balloon having a full state and a contracted state, the cryoablation catheter further comprising:

[0007] a flattening mechanism, the flattening mechanism comprising at least one pressing plate, the pressing plate being slidably arranged on the distal end portion of the catheter body in the axial direction of the catheter body, wherein in response to the balloon being switched from the contracted state to the full state, the pressing plate is opened in the radial direction of the catheter body and moves from the distal end to the proximal end along the catheter body, and in response to the balloon being switched from the full state to the contracted state, the pressing plate is closed in the radial direction of the catheter body to move from the proximal end to the distal end along the catheter body while maintaining abutting against the outer wall of the balloon.

[0008] In one of the embodiments, the pressing plate does not project beyond the outer wall of the catheter body in any radial cross-section of the catheter body when the balloon is in the deflated state.

[0009] In one of the embodiments, the pressing plate is in contact with the outer wall of the balloon in whole or in part when the balloon is in the deflated state.

[0010] In one of the embodiments, the pressing plate has a contact surface on the side facing the balloon, the contact surface is a circular arc surface, and the contact surface can cover the outer wall of the balloon when the balloon is in the deflated state.

[0011] In one of the embodiments, the pressing plate is in contact with the outer wall of the balloon in whole or in part when the balloon is in the deflated state.

[0012] In one of the embodiments, the pressing plate is in contact with the outer wall of the balloon in whole or in part when the balloon is in the deflated state.

[0013] In one of the embodiments, the pressing plate is in contact with the outer wall of the balloon in whole or in part when the balloon is in the deflated state.

[0014] In one of the embodiments, the pressing plate is in contact with the outer wall of the balloon in whole or in part when the balloon is in the deflated state.

[0015] In one of the embodiments, the pressing plate is in contact with the outer wall of the balloon in whole or in part when the balloon is in the deflated state.

[0016] In one of the embodiments, the pressing plate is in contact with the outer wall of the balloon in whole or in part when the balloon is in the deflated state.

[0017] The second elastic member is arranged on the catheter body, and one end of the second elastic member is connected to the pressing plate. In response to the balloon switching from the inflated state to the deflated state, the second elastic member can pull the pressing plate to contract along the radial direction of the catheter body.

[0018] In one embodiment, the first elastic member connected to the pressing plate is a plurality of elastic members, and the second elastic member connected to the pressing plate is also a plurality of elastic members.

[0019] In one embodiment, the reset unit includes an electromagnet and a power supply for supplying power to the electromagnet, wherein:

[0020] In response to the balloon switching from the deflated state to the inflated state, the electromagnet attracts the pressing plate, so that the pressing plate moves along the catheter body from the distal end to the proximal end. In response to the balloon switching from the inflated state to the deflated state, the electromagnet repels the pressing plate, so that the pressing plate moves along the catheter body from the proximal end to the distal end.

[0021] In one embodiment, the power supply changes the direction of the current flowing into the electromagnet to make the electromagnet attract or repel the pressing plate.

[0022] In one embodiment, the reset unit further includes a monitoring module connected to the power supply for monitoring the switching of the balloon between the inflated state and the deflated state.

[0023] In one embodiment, the reset unit includes at least one traction wire, one end of the traction wire being connected to the pressing plate.

[0024] In one embodiment, the catheter body includes an outer tube and an inner tube inserted into the outer tube, the distal end of the inner tube extending out of the outer tube, the distal end of the balloon being sealingly connected to the distal end of the inner tube, the inner cavity of the inner tube being a guide wire channel, the fluid channel being formed between the inner tube and the outer tube and being in communication with the inner cavity of the balloon, and the proximal end of the balloon being sealingly connected to the distal end of the outer tube.

[0025] In one embodiment, the cryoablation catheter further includes a handle, the distal end of the handle being connected to the proximal end of the outer tube.

[0026] In one embodiment, the handle is provided with an air inlet and an air outlet.

[0027] The fluid channel arranged in the catheter body includes an air inlet cavity and an air outlet cavity, one end of the air inlet cavity being in communication with the air inlet, and the other end of the air inlet cavity being in communication with the inner cavity of the balloon, one end of the air outlet cavity being in communication with the air outlet, and the other end of the air outlet cavity being in communication with the inner cavity of the balloon.

[0028] In one of the embodiments, the cross section of the pressing plate in the thickness direction is in the shape of an inverted trapezoid or a triangle.

[0029] A cryoablation device, comprising:

[0030] A cold source;

[0031] The cryoablation catheter according to any one of the preceding technical solutions is connected to the cold source.

[0032] When the balloon is switched from the inflated state to the deflated state, the force exerted by the balloon on the pressing plate disappears, the pressing plate is reset and folded along the radial direction of the catheter body, the pressing plate is close to the balloon to keep the state of abutting against the outer wall of the proximal end of the balloon, and the pressing plate moves on the catheter body from the proximal end to the distal end to smooth the bulges / creases on the surface of the balloon, so as to prevent the balloon from having adverse phenomena such as bulges / creases on the surface after being deflated, and keep the size of the balloon in the radial direction to be a small value, so that the balloon can be smoothly withdrawn to the guide catheter, and the cryoablation catheter is conveniently withdrawn to the outside of the patient.

[0033] On the other hand, the pressing plate abuts against the outer surface of the proximal end portion of the balloon, and when the balloon is switched from the inflated state to the deflated state, the pressing plate abutting against the surface of the balloon provides a crease for the balloon, so as to facilitate the balloon to be folded along the pressing plate and avoid the balloon to be stacked in disorder. In particular, when the cross section of the pressing plate is in the shape of an inverted trapezoid or a triangle, the pressing plate abutting against the balloon can more conveniently provide a crease for the balloon. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A structural schematic view of the cryoablation catheter provided in some embodiments in an inflated state.

[0035] Figure 2 A front view of the cryoablation catheter provided in some embodiments in an inflated state.

[0036] Figure 3 A Figure 2 A local enlarged view of region A in FIG. 8.

[0037] Figure 4 A structural schematic view of the cryoablation catheter provided in some embodiments in a deflated state.

[0038] Figure 5 is a front view of a cryoablation catheter provided in some embodiments in a deflated state.

[0039] Figure 6 is a front view of a cryoablation catheter provided in some embodiments in an inflated state. Figure 5 is a partial cross-sectional view at B-B.

[0040] Figure 7 is a front view of a cryoablation catheter provided in some embodiments in a deflated state.

[0041] Figure 8 is a front view of a handle provided in some embodiments.

[0042] Reference Signs:

[0043] 100, cryoablation catheter;

[0044] 110, catheter body; 111, outer tube; 112, inner tube; 1121, guide wire channel; 113, fluid channel; 1131, air inlet cavity; 1132, air return cavity; 120, balloon; 130, flattening mechanism; 131, pressing plate; 1311, abutting surface; 140, reset unit; 141, sliding assembly; 1411, sliding groove; 1412, sliding block; 142, stretching assembly; 1421, first elastic member; 1422, second elastic member; 143, electromagnet; 144, power supply; 150, handle; 151, air inlet; 152, air return; 153, air inlet tube; 154, air return tube. DETAILED DESCRIPTION

[0045] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the present application can be practiced in a variety of ways beyond the specific embodiments described herein without departing from the spirit of the present application, and that the present application is not limited to the specific embodiments disclosed below.

[0046] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0047] In addition, the terms "first", "second", and the like, if any, are used herein for descriptive purposes only and should not be construed as indicating or implying relative importance or identifying the number of the indicated technical characteristics. Thus, a feature defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0048] In the present application, unless otherwise explicitly specified and limited, if the terms "mounting", "connecting", "connecting", "fixing" and the like appear, these terms should be interpreted broadly. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0049] In the present application, unless otherwise explicitly specified and limited, if the first feature is described as "on" or "under" the second feature, etc., it can mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be the first feature directly above or obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "below", "below" and "below" the second feature can be the first feature directly below or obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0050] It should be noted that if an element is referred to as "fixed to" or "provided on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are only for illustrative purposes and do not represent the only implementation.

[0051] The technical solutions provided by the embodiments of the present application will be described below with reference to the drawings.

[0052] The proximal end described in the present application refers to the end close to the surgical operator, and the distal end refers to the end away from the surgical operator.

[0053] As Figures 1-6As shown, this application provides a cryoablation catheter 100, which includes a catheter body 110, a balloon 120, and a smoothing mechanism 130. The balloon 120 is connected to the catheter body 110, and the cryoablation catheter 100 is configured for cryoablation of the pulmonary vein vestibule. The catheter body 110 has an axial direction and has a distal and a proximal end in its axial direction. In this embodiment, the balloon 120 is connected to the distal end of the catheter body 110. The catheter body 110 has a fluid channel 113 communicating with the lumen of the balloon 120, and the balloon 120 is in an inflated state (…). Figure 1 The state shown) and the contraction state ( Figure 4 As shown in the diagram, when the filling medium is injected into the balloon 120 through the fluid channel 113, the balloon 120 inflates and can be placed against the lesion site. After the balloon 120 is positioned, a refrigerant is injected into the balloon 120 through the fluid channel 113 to perform cryoablation treatment on the target location. After ablation is completed, the refrigerant in the balloon 120 is discharged, and the balloon 120 contracts to facilitate the retraction of the cryoablation catheter 100.

[0054] The smoothing mechanism 130 includes at least one pressure plate 131, which is disposed at the distal end of the catheter body 110 and is slidable along the axial direction of the catheter body 110. In response to the balloon 120 switching from a contracted state to an inflated state, the balloon 120 inflates, and its outer wall contacts and applies force to the pressure plate 131, causing the pressure plate 131 to open radially along the catheter body 110. This prevents the pressure plate 131 from constraining or interfering with the inflation of the balloon 120. Simultaneously, the pressure plate 131 moves from the distal end to the proximal end of the catheter body 110, moving away from the balloon 120 to exit its contact area. This prevents the pressure plate 131 from interfering with the inflation of the balloon 120 and its contact with the lesion site during the inflation process. Conversely, in response to the balloon 120 switching from an inflated state to a deflated state, the force exerted by the balloon 120 on the pressure plate 131 disappears, and the pressure plate 131 retracts and retracts along the radial direction of the catheter body 110. This allows the pressure plate 131 to move from proximal to distal along the catheter body 110 while remaining abutted against the outer wall of the balloon 120. Simultaneously, the pressure plate 131 moves from proximal to distal along the catheter body 110, smoothing out any bulges or wrinkles on the surface of the balloon 120. This prevents undesirable bulges or wrinkles from appearing on the surface of the deflated balloon 120, maintaining a relatively small radial dimension of the balloon 120. The balloon 120 can then be smoothly retracted into the guiding catheter, facilitating the withdrawal of the cryoablation catheter 100 from the patient's body.

[0055] In one embodiment, such asFigure 4 As shown in FIG. 1, the balloon 120 is in the inflated state, and the pressing plate 131 is in the state of being pressed against the outer wall surface of the balloon 120. As shown in FIG. 2, the balloon 120 is in the deflated state, and the pressing plate 131 is in the state of not being pressed against the outer wall surface of the balloon 120. Figure 5 As shown in FIG. 2, when the balloon 120 is in the deflated state, the projection of the pressing plate 131 along any radial cross-section of the catheter body 110 does not exceed the outer wall of the catheter body 110, that is, the pressing plate 131 is located inside the catheter body 110 when the balloon 120 is in the deflated state, and the whole cryoablation catheter 100 is in the form of a long strip, facilitating the withdrawal operation of the cryoablation catheter 100.

[0056] Further, as shown in FIG. 2, the pressing plate 131 is in the state of being pressed against the outer wall surface of the balloon 120 when the balloon 120 is in the deflated state. Figure 4 As shown in FIG. 2, when the balloon 120 is in the deflated state, the projection of the pressing plate 131 along any radial cross-section of the catheter body 110 does not exceed the outer wall of the catheter body 110, that is, the pressing plate 131 is located inside the catheter body 110 when the balloon 120 is in the deflated state, and the whole cryoablation catheter 100 is in the form of a long strip, facilitating the withdrawal operation of the cryoablation catheter 100. Figure 5 As shown in FIG. 2, when the balloon 120 is in the deflated state, the projection of the pressing plate 131 along any radial cross-section of the catheter body 110 does not exceed the outer wall of the catheter body 110, that is, the pressing plate 131 is located inside the catheter body 110 when the balloon 120 is in the deflated state, and the whole cryoablation catheter 100 is in the form of a long strip, facilitating the withdrawal operation of the cryoablation catheter 100.

[0057] As shown in FIG. 2, when the balloon 120 is in the deflated state, the projection of the pressing plate 131 along any radial cross-section of the catheter body 110 does not exceed the outer wall of the catheter body 110, that is, the pressing plate 131 is located inside the catheter body 110 when the balloon 120 is in the deflated state, and the whole cryoablation catheter 100 is in the form of a long strip, facilitating the withdrawal operation of the cryoablation catheter 100. Figure 2 As shown in FIG. 2, when the balloon 120 is in the deflated state, the projection of the pressing plate 131 along any radial cross-section of the catheter body 110 does not exceed the outer wall of the catheter body 110, that is, the pressing plate 131 is located inside the catheter body 110 when the balloon 120 is in the deflated state, and the whole cryoablation catheter 100 is in the form of a long strip, facilitating the withdrawal operation of the cryoablation catheter 100.

[0058] In order to improve the flattening effect of the pressing plate 131 on the balloon 120, in an embodiment, as shown in FIG. 2, the pressing plate 131 has a pressing surface 1311 on the side facing the balloon 120, and the pressing surface 1311 is in the form of a circular arc surface. Figure 1 As shown in FIG. 2, when the balloon 120 is in the deflated state, the projection of the pressing plate 131 along any radial cross-section of the catheter body 110 does not exceed the outer wall of the catheter body 110, that is, the pressing plate 131 is located inside the catheter body 110 when the balloon 120 is in the deflated state, and the whole cryoablation catheter 100 is in the form of a long strip, facilitating the withdrawal operation of the cryoablation catheter 100. Figure 2As shown, the pressing plates 131 are multiple, and the multiple pressing plates 131 are arranged along the circumferential direction of the catheter body 110. In response to the balloon 120 being switched from the inflated state to the deflated state, the multiple pressing plates 131 are folded along the radial direction of the catheter body 110, and when the catheter body 110 moves from the proximal end to the distal end, the multiple pressing plates 131 can simultaneously abut against the outer wall of the balloon 120 to perform a smoothing operation on the outer wall of the balloon 120. The multiple pressing plates 131 can seamlessly abut against the outer wall of the balloon 120, preventing the balloon 120 from having protruding defects such as bulges or wrinkles in some areas due to the leakage of the pressing plates 131, thereby improving the smoothing effect of the pressing plates 131 on the outer wall of the balloon 120. As in the present embodiment, as Figure 2 As shown, the pressing plates 131 are four, and the four pressing plates 131 are arranged along the circumferential direction of the catheter body 110. When the balloon 120 is in the deflated state, the four pressing plates 131 can be seamlessly arranged on the surface of the outer wall of the balloon 120, and the four pressing plates 131 simultaneously perform a smoothing operation on the surface of the outer wall of the balloon 120. Of course, in other feasible embodiments, the number of pressing plates 131 can also be two, three, five, or other numbers. The specific number of pressing plates 131 is not limited in the present application.

[0059] In order to realize the follow-up movement of the pressing plates 131 in response to the switching of the balloon 120 between the inflated state and the deflated state, in an embodiment, as Figures 1-5 As shown, the smoothing mechanism 130 further includes a reset unit 140. The reset unit 140 is in transmission connection with the pressing plates 131. In response to the balloon 120 being switched from the inflated state to the deflated state, the reset unit 140 controls the pressing plates 131 to be folded along the radial direction of the catheter body 110 and to move on the catheter body 110 from the proximal end to the distal end, to perform a smoothing operation on the protrusions such as bulges or wrinkles on the surface of the balloon 120, to prevent the balloon 120 from having protruding defects such as bulges or wrinkles on the surface after being deflated, to keep the size of the balloon 120 in the radial direction as a smaller value, and to allow the balloon 120 to be smoothly withdrawn into the guide catheter, facilitating the withdrawal of the cryoablation catheter 100 out of the patient's body.

[0060] In some embodiments, as Figures 1-5The reset unit 140 includes a sliding assembly 141 and a stretching assembly 142. The sliding assembly 141 is arranged on the outer surface of the catheter body 110 and is slidable along the axial direction of the catheter body 110. One end of the pressing plate 131 is connected to the sliding assembly 141. In response to the balloon 120 switching from the deflated state to the inflated state, the balloon 120 expands and exerts a force on the pressing plate 131. After the sliding assembly 141 is subjected to the external force, the sliding assembly 141 drives the pressing plate 131 to move along the catheter body 110 from the distal end to the proximal end. The pressing plate 131 moves away from the balloon 120 to exit the contact area of the balloon 120. Conversely, in response to the balloon 120 switching from the inflated state to the deflated state, the force exerted by the balloon 120 on the pressing plate 131 disappears. The sliding assembly 141 resets and drives the pressing plate 131 to move along the catheter body 110 from the proximal end to the distal end. The pressing plate 131 approaches the balloon 120 to maintain the state of abutting against the outer wall of the balloon 120 and smooths the bulges or wrinkles on the surface of the balloon 120. The stretching assembly 142 is arranged on the catheter body 110 and is connected to the pressing plate 131. In response to the balloon 120 switching from the inflated state to the deflated state, the stretching assembly 142 controls the pressing plate 131 to fold along the radial direction of the catheter body 110 and move on the catheter body 110 from the proximal end to the distal end. The pressing plate 131 can be pressed against the surface of the outer wall of the balloon 120 to smooth the protrusions such as bulges or wrinkles on the surface of the balloon 120.

[0061] It should be noted that the stretching assembly 142 is elastic. In response to the balloon 120 switching from the deflated state to the inflated state, the stretching assembly 142 can elastically displace so that the pressing plate 131 expands along the radial direction of the catheter body 110 as the balloon 120 inflates. This avoids the constraint and interference of the pressing plate 131 on the inflation of the balloon 120. At the same time, the pressing plate 131 moves on the catheter body 110 from the distal end to the proximal end. The pressing plate 131 moves away from the balloon 120 to exit the contact area of the balloon 120, thereby preventing the interference of the pressing plate 131 on the inflation of the balloon 120 and the abutment of the balloon 120 with the lesion site during the inflation of the balloon 120.

[0062] In order to enable the sliding assembly 141 to drive the pressing plate 131 to move along the axial direction of the catheter body 110, in one embodiment, as shown in Figures 1-5As shown, the sliding assembly 141 comprises a sliding groove 1411 and a sliding block 1412, the sliding block 1412 is cooperated with the sliding groove 1411, for example, the sliding block 1412 is slidably arranged in the sliding groove 1411. The sliding groove 1411 is protruded on the outer surface of the catheter body 110, since the catheter body 110 of the cryoablation catheter 100 has a small size in the axial direction, the sliding groove 1411 is protruded on the outer surface of the catheter body 110, which will not damage the overall structure of the catheter body 110, and there is no need to increase the overall structural design of the catheter body 110 for setting the sliding groove 1411. In other possible embodiments, the sliding groove 1411 can also be arranged on the catheter body 110 by opening. Moreover, the extension direction of the sliding groove 1411 is consistent with the axial direction of the catheter body 110, one end of the pressing plate 131 is connected to the sliding block 1412 by welding, screwing or other methods, when the sliding block 1412 slides in the sliding groove 1411, the sliding block 1412 can drive the pressing plate 131 to move along the axial direction of the catheter body 110, so that the pressing plate 131 moves on the catheter body 110 from the distal end to the proximal end during the inflation process of the balloon 120, the pressing plate 131 moves away from the balloon 120 to exit the contact area of the balloon 120, and at the same time, the pressing plate 131 moves on the catheter body 110 from the proximal end to the distal end during the deflation process of the balloon 120, the pressing plate 131 moves close to the balloon 120 to keep in contact with the outer wall of the balloon 120.

[0063] Preferably, as Figure 1 As shown, the sliding groove 1411 is one of an S-shaped groove, a V-shaped groove or a spiral groove. For example, in one embodiment, the sliding groove 1411 can be an S-shaped groove. For another example, in another embodiment, the sliding groove 1411 can be a V-shaped groove. For still another example, in still another embodiment, the sliding groove 1411 can be a spiral groove. In the above-mentioned embodiments, the sliding groove 1411 is arranged as one of an S-shaped groove, a V-shaped groove or a spiral groove, when the sliding block 1412 slides in the sliding groove 1411, the sliding block 1412 drives the pressing plate 131 to move along the axial direction of the catheter body 110 while rotating around the catheter body 110, especially in response to the balloon 120 switching from the inflated state to the deflated state, the pressing plate 131 can rotate and smooth the surface of the outer wall of the balloon 120, which improves the smoothing effect of the pressing plate 131 on the surface of the outer wall of the balloon 120.

[0064] Of course, in other possible embodiments, the shape of the sliding groove 1411 can also be a W-shaped groove or other shapes, and the specific shape of the sliding groove 1411 is not limited in the present application, which can be arranged according to the needs of the operator.

[0065] Further, in one embodiment, as Figures 1-5As shown, the stretching assembly 142 includes a first elastic member 1421 and a second elastic member 1422. One end of the first elastic member 1421 is arranged on the catheter body 110 by welding, clamping or the like, and the other end of the first elastic member 1421 is connected with the pressing plate 131, for example, the other end of the first elastic member 1421 can be connected on the sliding block 1412 by welding, clamping or the like, in response to the balloon 120 switching from the inflated state to the deflated state, the first elastic member 1421 can push the pressing plate 131 to move on the catheter body 110 from the proximal end to the distal end. One end of the second elastic member 1422 is arranged on the catheter body 110 by welding, clamping or the like, and the other end of the second elastic member 1422 is connected with the pressing plate 131, in response to the balloon 120 switching from the inflated state to the deflated state, the second elastic member 1422 can pull the pressing plate 131 to contract along the radial direction of the catheter body 110. In this embodiment, the first elastic member 1421 and the second elastic member 1422 can be return springs.

[0066] Specifically, as in this embodiment, when the first elastic member 1421 is not subjected to any force, the first elastic member 1421 is in a stretched state, and when the second elastic member 1422 is not subjected to any force, the second elastic member 1422 is in a compressed state, at this time, the pressing plate 131 is at the distal end position of the catheter body 110, and the pressing plate 131 is contracted on the catheter body 110. When the balloon 120 switches from the deflated state to the inflated state, the balloon 120 exerts a force (such as the force F shown) on the pressing plate 131, at this time, the component of the force F along the axial direction of the catheter body 110 (such as the force F1 shown) can press the first elastic member 1421, the first elastic member 1421 is compressed, and at the same time, the pressing plate 131 moves on the catheter body 110 from the distal end to the proximal end, the pressing plate 131 moves away from the balloon 120 to exit the fitting area of the balloon 120, and the component of the force F along the radial direction of the catheter body 110 (such as the force F2 shown) can pull the second elastic member 1422, the second elastic member 1422 is stretched, and at the same time, the pressing plate 131 is opened along the radial direction of the catheter body 110, avoiding the constraint interference of the pressing plate 131 to the inflation of the balloon 120. Figure 3 Figure 3 Figure 3 Figure 3 ​​​The force F1 and F2 shown acting on the pressing plate 131 disappears, at this time, the first elastic member 1421 and the second elastic member 1422 will be elastically reset, the first elastic member 1421 is stretched and resets and pushes the pressing plate 131 to move on the catheter body 110 from the proximal end to the distal end, while the second elastic member 1422 is contracted and resets and pulls the pressing plate 131 to contract along the radial direction of the catheter body 110, the pressing plate 131 is close to the balloon 120 to keep the state of adhering to the outer wall of the balloon 120, and the bulge / wrinkle on the surface of the balloon 120 is smoothed to prevent the balloon 120 from appearing bulge / wrinkle and other protruding adverse phenomena on its surface after shrinking.

[0067] Preferably, in the present embodiment, as Figure 1 With Figure 2 As shown, the first elastic member 1421 connected to the pressing plate 131 is multiple, which can prevent the first elastic member 1421 from bending due to excessive force during movement and improve the reliable control of the first elastic member 1421 on the movement of the pressing plate 131 in the axial direction of the catheter body 110. Similarly, the second elastic member 1422 connected to the pressing plate 131 is also multiple, which can prevent the second elastic member 1422 from bending due to excessive force during movement and improve the reliable control of the second elastic member 1422 on the movement of the pressing plate 131 in the radial direction of the catheter body 110. Among them, the first elastic member 1421 can be two, three or other quantities, and the second elastic member 1422 can be two, three or other quantities. The specific number of the first elastic member 1421 and the second elastic member 1422 is not limited in the present application.

[0068] In another part of the embodiment, as Figure 7As shown, the reset unit 140 includes an electromagnet 143 and a power supply 144 for supplying power to the electromagnet 143. The electromagnet 143 is arranged at a proximal end of the catheter body 110, i.e., the electromagnet 143 is arranged at one side of the pressing plate 131. The power supply 144 changes the direction of current flowing into the electromagnet 143 to cause the electromagnet 143 to attract or repel the pressing plate 131. That is, when the power supply 144 supplies current flowing into the electromagnet 143 in a certain direction, the electromagnet 143 exhibits an attractive effect on the pressing plate 131. When the power supply 144 supplies current flowing into the electromagnet 143 in a direction opposite to the above direction, the electromagnet 143 exhibits a repulsive effect on the pressing plate 131. In response to the balloon 120 switching from the deflated state to the inflated state, the electromagnet 143 attracts the pressing plate 131 to cause the pressing plate 131 to move on the catheter body 110 from the distal end to the proximal end. The pressing plate 131 moves away from the balloon 120 to exit the contact area of the balloon 120, thereby preventing the pressing plate 131 from interfering with the inflation of the balloon 120 and the contact of the balloon 120 with the lesion site during the inflation of the balloon 120. In response to the balloon 120 switching from the inflated state to the deflated state, the electromagnet 143 repels the pressing plate 131 to cause the pressing plate 131 to move on the catheter body 110 from the proximal end to the distal end. The pressing plate 131 moves close to the balloon 120 to keep in contact with the outer wall of the balloon 120, thereby smoothing the protrusions such as bulges and wrinkles on the surface of the balloon 120 to prevent the balloon 120 from having adverse phenomena such as bulges and wrinkles on the surface thereof after deflation. In this embodiment, the pressing plate 131 can be arranged on the sliding block 1412. The electromagnet 143 attracts or repels the sliding block 1412 to cause the sliding block 1412 to slide in the sliding groove 1411 to control the movement of the pressing plate 131 in the axial direction of the catheter body 110.

[0069] It should be noted that in other possible embodiments, the electromagnet 143 can also be arranged at a distal end of the catheter body 110, i.e., the electromagnet 143 is arranged at the other side of the pressing plate 131. In response to the balloon 120 switching from the deflated state to the inflated state, the electromagnet 143 repels the pressing plate 131 to cause the pressing plate 131 to move on the catheter body 110 from the distal end to the proximal end. In response to the balloon 120 switching from the inflated state to the deflated state, the electromagnet 143 attracts the pressing plate 131 to cause the pressing plate 131 to move on the catheter body 110 from the proximal end to the distal end. In addition, in this embodiment, the pressing plate 131 has magnetic adsorption properties because the electromagnet 143 needs to attract or repel the pressing plate 131. For example, the pressing plate 131 is made of ferrous material and is subjected to corresponding corrosion prevention and rust prevention treatments. The pressing plate 131 meets the magnetic adsorption property condition and will not cause secondary harm to the human body. Of course, the pressing plate 131 is not limited to being made in the above manner. The pressing plate 131 can also be arranged according to requirements as long as the pressing plate 131 has magnetic adsorption properties and will not cause secondary harm to the human body.

[0070] Further, as shown in FIG. 2, the reset unit 140 includes a reset button 142.Figure 7 As shown, the reset unit 140 further comprises a monitoring module (not shown in the figure). The monitoring module is in signal connection with the power supply 144, and is used to monitor the switching of the balloon 120 between the inflated state and the deflated state. When the monitoring module detects that the balloon 120 switches from the deflated state to the inflated state, the monitoring module feeds back a signal to the power supply 144, and the power supply 144 passes a current in a certain direction into the electromagnet 143, so that the electromagnet 143 exhibits an attractive effect on the pressing plate 131, causing the pressing plate 131 to move on the catheter body 110 from the distal end towards the proximal end. Conversely, when the monitoring module detects that the balloon 120 switches from the inflated state to the deflated state, the monitoring module feeds back a signal to the power supply 144, and the power supply 144 passes a current in a direction opposite to the above-mentioned direction into the electromagnet 143, so that the electromagnet 143 exhibits a repulsive effect on the pressing plate 131, causing the pressing plate 131 to move on the catheter body 110 from the proximal end towards the distal end. The monitoring module can be a displacement sensor or a pressure sensor arranged on the pressing plate 131, which senses the change in the position of the pressing plate 131 or the change in the pressure on the pressing plate 131 to monitor the state change of the balloon 120; or the monitoring module can be an imager, which takes images in or outside the patient's body and feeds back to the operator to monitor the state change of the balloon 120 in real time. The specific type of the monitoring module is not limited in the present application.

[0071] In yet another part of the embodiments, as shown in Figures 1-5 As shown, the reset unit 140 comprises at least one traction wire (not shown in the figure), one end of the traction wire being connected to the pressing plate 131, and the other end of the traction wire being exposed to the outside of the catheter body 110 for the operator to hold and operate. In the present embodiment, the traction wire has a certain strength. In response to the switching of the balloon 120 from the deflated state to the inflated state, the operator can pull the traction wire, causing the traction wire to drive the pressing plate 131 to move on the catheter body 110 from the distal end towards the proximal end, and the pressing plate 131 moves away from the balloon 120 to exit the fitting area of the balloon 120, preventing the interference of the pressing plate 131 with the inflation of the balloon 120 and the fitting of the balloon 120 to the lesion site during the inflation of the balloon 120. In response to the switching of the balloon 120 from the inflated state to the deflated state, the operator can push the traction wire, causing the traction wire to drive the pressing plate 131 to move on the catheter body 110 from the proximal end towards the distal end, and the pressing plate 131 approaches the balloon 120 to keep in close contact with the outer wall of the balloon 120, and to smooth the protrusions such as bulges and wrinkles on the surface of the balloon 120, preventing the adverse phenomenon of the protrusions such as bulges and wrinkles on the surface of the balloon 120 after deflation.

[0072] In one embodiment, as shown in Figures 1-6As shown, the catheter body 110 comprises an outer tube 111 and an inner tube 112, the inner tube 112 is inserted into the outer tube 111, for example, the proximal end of the inner tube 112 is inserted into the outer tube 111, and the distal end of the inner tube 112 extends out of the outer tube 111. In this embodiment, the pressure plate 131 is slidably arranged on the distal end portion of the outer tube 111 along the axial direction of the outer tube 111, and in response to the switching of the balloon 120 from the deflated state to the inflated state, the pressure plate 131 expands along the radial direction of the outer tube 111 and moves on the outer tube 111 from the distal end to the proximal end while abutting against the outer wall of the balloon 120, and in response to the switching of the balloon 120 from the inflated state to the deflated state, the pressure plate 131 contracts along the radial direction of the outer tube 111 to move on the outer tube 111 from the proximal end to the distal end while abutting against the outer wall of the balloon 120. The fluid channel 113 is formed between the inner tube 112 and the outer tube 111 and communicates with the inner cavity of the balloon 120, when the inflation medium (for example, inert gas such as nitrogen, argon, etc.) is injected into the balloon 120 through the fluid channel 113, the balloon 120 is inflated and can abut against the lesion site, and after the balloon 120 is positioned, the cryogenic refrigerant is injected into the balloon 120 through the fluid channel 113 to perform cryogenic ablation treatment on the target site; after the ablation is completed, the cryogenic refrigerant (for example, liquid nitrogen) in the balloon 120 is discharged, the balloon 120 is deflated and abuts against the inner tube 112, facilitating the withdrawal of the cryogenic ablation catheter 100. In this embodiment, the proximal end of the balloon 120 is sealingly connected to the distal end of the outer tube 111, and the distal end of the balloon 120 is sealingly connected to the distal end of the inner tube 112, for example, a sealing ring is arranged at the connection between the proximal end of the balloon 120 and the distal end of the outer tube 111, and a sealing ring is also arranged at the connection between the distal end of the balloon 120 and the distal end of the inner tube 112, which can prevent the inflation medium or the cryogenic refrigerant from leaking at the connection between the balloon 120 and the outer tube 111 and / or the connection between the balloon 120 and the inner tube 112 when the inflation medium or the cryogenic refrigerant is injected into the balloon 120 through the fluid channel 113. Furthermore, the inner cavity of the inner tube 112 is a guide wire channel 1121, and the guide wire channel 1121 can pass a guide wire (not shown in the figure), when the cryogenic ablation catheter 100 needs to be pushed to the lesion site, the guide wire is inserted into the guide wire channel 1121, so that the cryogenic ablation catheter 100 can reach the lesion site along the guide wire, which plays a guiding and positioning role in pushing the cryogenic ablation catheter 100, and facilitates the operator to push the cryogenic ablation catheter 100 to the lesion site.

[0073] In an embodiment, as shown in Figure 1 , Figure 2 and Figure 8 As shown, the cryogenic ablation catheter 100 further comprises a handle 150, and the distal end of the handle 150 is connected to the proximal end of the outer tube 111 by sleeving, sleeving, or the like. The handle 150 can facilitate the operator to perform cryogenic ablation operation and withdrawal operation on the cryogenic ablation catheter 100.

[0074] Further, as shown in Figure 8As shown, the handle 150 is provided with an air inlet 151 and an air outlet 152. The air inlet 151 is connected with an air inlet pipe 153 by inserting, screwing or the like. The air inlet pipe 153 is used to connect to the cold source of the cryoablation device to provide refrigerant for the cryoablation catheter 100. The air outlet 152 is connected with an air outlet pipe 154 by inserting, screwing or the like. The air outlet pipe 154 is connected to the cold source recovery device of the cryoablation device to recover the refrigerant in the cryoablation catheter 100, thereby improving the utilization rate of the refrigerant.

[0075] Continuing to refer to Figure 6 As shown, the fluid channel 113 provided in the catheter body 110 includes an air inlet cavity 1131 and an air outlet cavity 1132. One end of the air inlet cavity 1131 is in communication with the air inlet 151, and the other end of the air inlet cavity 1131 is in communication with the balloon 120. One end of the air outlet cavity 1132 is in communication with the air outlet 152, and the other end of the air outlet cavity 1132 is in communication with the balloon 120. That is, the air inlet pipe 153, the air inlet 151 and the air inlet cavity 1131 can form a complete air inlet circuit, and the air outlet cavity 1132, the air outlet 152 and the air outlet pipe 154 can form a complete air outlet circuit. When the inflation medium is injected into the balloon 120 through the air inlet pipe 153, the air inlet 151 and the air inlet cavity 1131, the balloon 120 is inflated, and then the refrigerant can be further introduced into the balloon 120 through the air inlet pipe 153, the air inlet 151 and the air inlet cavity 1131 to perform cryoablation treatment on the lesion site. Conversely, after the cryoablation treatment on the lesion site is completed, the refrigerant can flow out of the balloon 120 through the air outlet cavity 1132, the air outlet 152 and the air outlet pipe 154 to be recovered, thereby avoiding the loss of the refrigerant and improving the utilization rate of the refrigerant. Moreover, the refrigerant can circulate in the air inlet circuit and the air outlet circuit, thereby improving the cryoablation treatment effect of the cryoablation catheter 100 on the lesion site.

[0076] In an embodiment, as shown in Figure 2 As shown in Figure 5 As shown, the cross section of the pressing plate 131 in the thickness direction is an inverted trapezoid or a triangle. The pressing plate 131 abuts against the outer surface of the proximal end portion of the balloon 120. When the balloon 120 switches from the inflated state to the deflated state, the pressing plate 131 abutting against the balloon 120 provides a crease for the balloon 120, thereby facilitating the folding of the balloon 120 along the pressing plate 131 and avoiding the disorderly stacking of the balloon 120. In particular, when the cross section of the pressing plate 131 is an inverted trapezoid or a triangle, the pressing plate 131 abutting against the balloon 120 can more easily provide a crease for the balloon 120.

[0077] In addition, as shown in Figures 1-6As shown, the application also provides a cryoablation device (not shown in the figure). The cryoablation device comprises a cold source (not shown in the figure) and the cryoablation catheter 100 according to any one of the above technical solutions, the cryoablation catheter 100 is connected to the cold source, for example, the cold source is connected to the proximal end of the catheter body 110.

[0078] When the inflation medium (for example, normal temperature nitrogen) is injected into the balloon 120 lumen through the above-mentioned cryoablation device, the balloon 120 switches from the deflated state to the inflated state, the balloon 120 expands and exerts a force on the pressing plate 131, the pressing plate 131 opens along the radial direction of the catheter body 110, avoiding the constraint interference of the pressing plate 131 to the inflation of the balloon 120, at the same time, the pressing plate 131 moves on the catheter body 110 from the distal end to the proximal end, the pressing plate 131 moves away from the balloon 120 to exit the adhesion area of the balloon 120, preventing the interference of the pressing plate 131 to the inflation of the balloon 120 and the adhesion to the lesion site during the inflation of the balloon 120. Conversely, after the ablation to the lesion site is completed, the refrigerant in the balloon 120 flows back to the cryoablation device, the balloon 120 switches from the inflated state to the deflated state, the force exerted by the balloon 120 on the pressing plate 131 disappears, the pressing plate 131 resets and folds along the radial direction of the catheter body 110, the pressing plate 131 approaches the balloon 120 to maintain the state of adhering to the proximal outer wall of the balloon 120, at the same time, the pressing plate 131 moves on the catheter body 110 from the proximal end to the distal end, smoothing the bulge / crease on the surface of the balloon 120, preventing the balloon 120 from having adverse phenomena such as bulge / crease on its surface after deflation.

[0079] The technical features of the above-mentioned embodiments can be combined in any way. In order to make the description simple, not all possible combinations of the technical features in the above-mentioned embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0080] The above-mentioned embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as a limitation to the patent scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A cryoablation catheter, comprising a catheter body and a balloon connected to the catheter body, the catheter body having a distal end and a proximal end opposite each other in its axial direction, the catheter body having a fluid channel communicating with the lumen of the balloon, the balloon having an inflated state and a deflated state, characterized in that, The cryoablation catheter also includes: A smoothing mechanism includes at least one pressure plate and a reset unit. The pressure plate is slidably disposed on the distal portion of the catheter body along the axial direction of the catheter body. The reset unit is drivenly connected to the pressure plate. The reset unit controls the pressure plate to retract along the radial direction of the catheter body and move along the catheter body from the proximal end to the distal end. The reset unit includes a sliding component and a stretching component. The sliding component is slidably disposed on the outer surface of the catheter body along the axial direction of the catheter body. One end of the pressure plate is connected to the sliding component. The stretching component is disposed on the catheter body and connected to the pressure plate. In response to the balloon switching from a contracted state to an inflated state, the pressure plate opens along the radial direction of the catheter body and moves along the catheter body from the distal end to the proximal end. In response to the balloon switching from an inflated state to a contracted state, the stretching component controls the pressure plate to retract along the radial direction of the catheter body so as to move along the catheter body from the proximal end to the distal end while remaining abutting against the outer wall of the balloon.

2. The cryoablation catheter according to claim 1, characterized in that, When the balloon is in a contracted state, the projection of the pressure plate onto any section along the radial direction of the catheter body does not exceed the outer wall of the catheter body.

3. The cryoablation catheter according to claim 1, characterized in that, When the balloon is in a contracted state, the pressure plate is entirely or at least partially abutted against the outer wall of the balloon.

4. The cryoablation catheter according to claim 3, characterized in that, The pressure plate has a contact surface on the side facing the balloon. The contact surface is an arc surface, and when the balloon is in a contracted state, the contact surface can cover the outer wall of the balloon.

5. The cryoablation catheter according to claim 1, characterized in that, The pressure plate consists of multiple pieces, and these multiple pressure plates are spaced apart along the circumferential direction of the conduit body.

6. The cryoablation catheter according to claim 1, characterized in that, The sliding assembly includes a groove and a slider that cooperates with the groove. The groove protrudes from the outer surface of the catheter body and extends in the same direction as the axial direction of the catheter body. One end of the pressure plate is connected to the slider.

7. The cryoablation catheter according to claim 6, characterized in that, The groove is one of an S-shaped groove, a V-shaped groove, or a spiral groove.

8. The cryoablation catheter according to claim 1, characterized in that, The stretching assembly includes a first elastic element and a second elastic element. The first elastic element is disposed on the catheter body and one end of it is connected to the pressure plate. In response to the balloon switching from an inflated state to a contracted state, the first elastic element can push the pressure plate to move along the catheter body from the proximal end to the distal end. The second elastic element is disposed on the catheter body, and one end of it is connected to the pressure plate. In response to the balloon switching from an inflated state to a contracted state, the second elastic element can pull the pressure plate to retract along the radial direction of the catheter body.

9. The cryoablation catheter according to claim 8, characterized in that, There are multiple first elastic elements connected to the pressure plate, and there are also multiple second elastic elements connected to the pressure plate.

10. The cryoablation catheter according to claim 1, characterized in that, The reset unit includes an electromagnet and a power supply for supplying power to the electromagnet, wherein: In response to the balloon switching from a contracted state to an inflated state, the electromagnet attracts the pressure plate, causing the pressure plate to move along the catheter body from the distal end to the proximal end; in response to the balloon switching from an inflated state to a contracted state, the electromagnet repels the pressure plate, causing the pressure plate to move along the catheter body from the proximal end to the distal end.

11. The cryoablation catheter according to claim 10, characterized in that, The power source changes the direction of the current flowing into the electromagnet, causing the electromagnet to attract or repel the pressure plate.

12. The cryoablation catheter according to claim 10, characterized in that, The reset unit also includes a monitoring module, which is connected to the power signal and is used to monitor the switching of the balloon between the inflated and contracted states.

13. The cryoablation catheter according to claim 1, characterized in that, The reset unit includes at least one traction wire, one end of which is connected to the pressure plate.

14. The cryoablation catheter according to claim 1, characterized in that, The catheter body includes an outer tube and an inner tube inserted into the outer tube. The distal end of the inner tube extends out of the outer tube. The distal end of the balloon is sealed to the distal end of the inner tube. The inner lumen of the inner tube is a guidewire channel. A fluid channel communicating with the inner lumen of the balloon is formed between the inner tube and the outer tube. The proximal end of the balloon is sealed to the distal end of the outer tube.

15. The cryoablation catheter according to claim 14, characterized in that, The cryoablation catheter also includes a handle, the distal end of which is connected to the proximal end of the outer tube.

16. The cryoablation catheter according to claim 15, characterized in that, The handle is provided with an air inlet and an air outlet; The fluid channel disposed within the catheter body includes an air inlet chamber and an air return chamber. One end of the air inlet chamber is connected to the air inlet port, and the other end is connected to the inner cavity of the balloon. One end of the air return chamber is connected to the air return port, and the other end is connected to the inner cavity of the balloon.

17. The cryoablation catheter according to claim 1, characterized in that, The pressure plate has an inverted trapezoidal or triangular cross-section in its thickness direction.

18. A cryoablation device, characterized in that, The cryoablation device includes: Cold source; The cryoablation catheter as described in any one of claims 1-17, wherein the cryoablation catheter is connected to the cold source.

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