An interventional catheter

Abstract

This invention discloses an interventional catheter and related to the field of medical device technology. Specifically, it includes a buffer structure with a buffer cavity within it. By providing the buffer cavity, the interventional catheter and related device compensate for the change in effective volume of the sheath body caused by the movement of the core within the sheath body. This allows excess liquid medium within the sheath body to be stored in the buffer cavity, or excess cavity within the sheath body to be filled by the liquid medium within the buffer cavity. This prevents liquid medium leakage or external gas entry at the interface of the sheath body. Simultaneously, it solves the problem of increased resistance to movement of treatment or detection components due to pressure changes within the sheath body, increases the displacement consistency between the treatment or detection components and the pusher seat, and thus improves the detection accuracy and service life of the device.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to an interventional catheter. Background Technology

[0002] In interventional catheters, the rotation and movement of therapeutic or diagnostic components are typically required to perform therapeutic or diagnostic functions. In well-sealed catheter environments, due to the small gap between the core and the inner wall of the sheath, the core's retraction can momentarily create a vacuum within the sheath, which can persist for a period. During this time, air can be drawn into the proximal end of the sheath due to negative pressure. Simultaneously, the pressure inside the sheath increases instantaneously when the core moves forward, potentially causing leakage of the liquid medium at the sheath's interface. Furthermore, uneven pressure distribution can hinder the accurate transmission of actuation force from the proximal end to the distal therapeutic or diagnostic components. All of these adverse effects can negatively impact treatment and diagnostic outcomes, reduce device lifespan, and even endanger the patient's health.

[0003] In summary, how to solve the problems of air intake or liquid medium leakage caused by the sharp rise and fall of pressure during operation due to the movement of the core, as well as the problem of insufficient transmission consistency, are problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide an interventional catheter to overcome at least one problem existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An interventional catheter includes: a sheath body having a distally closed lumen, the lumen being elongated; a core having a functional component at its distal end for treating or detecting tissue, the core being fitted within the lumen; a connector connected to the proximal end of the core and having an overflow cavity communicating with the proximal end of the lumen; a buffer structure attached to the sheath body or the connector, the buffer structure having a buffer cavity; and a liquid medium, a fixed amount of which is pre-injected into the gap between the lumen and the core, the buffer cavity, and the overflow cavity; wherein...

[0007] The sheath body or the connector is provided with a pressure relief hole that communicates with the buffer cavity. The gap and the overflow cavity form a first flow channel. The pressure relief hole and the buffer cavity form a second flow channel. The first flow channel and the second flow channel communicate with each other and are set at an angle.

[0008] In some embodiments, a fixed amount of the liquid medium fills the first flow channel and the second flow channel;

[0009] The buffer cavity has elastic walls, and its volume can automatically expand or contract according to changes in its internal pressure.

[0010] In some embodiments, the maximum expandable volume of the buffer cavity is not less than the maximum value of the volume change of the liquid medium caused by the movement of the core within the first flow channel, or...

[0011] The maximum volume of the buffer cavity is not less than the maximum value of the volume change of the liquid medium caused by the movement of the core in the first flow channel.

[0012] In some embodiments, the device further includes a push seal and a push assembly; the push seal is disposed at the proximal end of the overflow cavity and slides against the core, the distal end of the core passes through the overflow cavity and extends into the inner cavity; the core extends into the inner cavity and is driven by the push assembly to move relative to the inner cavity.

[0013] In some embodiments, the core is driven by the pushing component to move relative to the inner cavity, and the core is moved to change its portion located within the first flow channel, thereby changing the volume of the liquid medium within the first flow channel, wherein...

[0014] When the functional component moves toward the distal end near the inner cavity, the liquid medium flows from the first flow channel to the second flow channel and expands the buffer cavity to increase the volume of the buffer cavity.

[0015] When the functional component moves toward the distal end away from the inner cavity, the liquid medium flows from the second flow channel to the first flow channel and contracts the buffer cavity to reduce the volume of the buffer cavity.

[0016] In some embodiments, the pushing component includes a rigid tube sleeved over the proximal end of the core;

[0017] The rigid tube moves synchronously with the core and changes the portion of the rigid tube located within the first flow channel, thereby changing the volume of the liquid medium within the inner cavity;

[0018] The maximum expandable volume of the buffer cavity or the maximum volume of the buffer cavity is V, where V≥πR²L, where L is the maximum stroke of the rigid tube moving synchronously with the core, and R is the radius of the rigid tube.

[0019] In some embodiments, the buffer cavity is arranged circumferentially around the first flow channel, and the sheath body or the connector is provided with pressure relief holes, and at least one set of the pressure relief holes is provided at the proximal end of the buffer cavity and communicates with the first flow channel.

[0020] In some embodiments, the radial dimension of the buffer cavity gradually decreases from the proximal end to the distal end; or, the buffer cavity is spherical, ellipsoidal, or spindle-shaped; or, the buffer cavity is arranged parallel to the first flow channel; the wall thickness constituting the buffer cavity is 0.1mm-5mm.

[0021] In some embodiments, the inner wall of the buffer cavity and / or the sheath body is provided with an anti-corrosion layer to prevent the liquid medium from corroding the inner wall of the buffer cavity and / or the sheath body.

[0022] In some embodiments, the cushioning structure is made of silicone, and / or the cushioning structure is made of a highly transparent material.

[0023] The interventional catheter provided by this invention has at least the following advantages compared with the prior art:

[0024] 1. By setting up a buffer cavity that is connected to the inner cavity of the sheath body and set at an angle, it is used to store the liquid medium flowing out of the first flow channel or to replenish the insufficient liquid medium in the first flow channel, thereby balancing the pressure in the inner cavity of the sheath body. This solves the problem of the sudden rise and fall of pressure in the first flow channel caused by the movement of the core in the sheath body, thereby avoiding the leakage of liquid medium or the entry of external gas caused by the pressure change, and effectively increasing the service life of the equipment.

[0025] 2. By setting up a buffer cavity, the pressure inside the sheath body is balanced, thereby avoiding the increase in core resistance caused by changes in the internal pressure of the sheath body. This improves the displacement consistency between the treatment or detection components and the push seat, and enhances the detection accuracy of the device. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of an existing interventional catheter design.

[0028] Figure 2 A schematic diagram of the design scheme of the sheath body and core in the prior art;

[0029] Figure 3 This is a schematic diagram of the proximal end of a specific sheath assembly provided by the present invention;

[0030] Figure 4This is a schematic diagram of the structure of the specific rotating component, pushing component, and handle assembly provided by the present invention;

[0031] Figure 5 A schematic diagram of the specific buffer structure provided by the present invention;

[0032] Figure 6 A schematic diagram of another embodiment of the specific buffer structure provided by the present invention;

[0033] Figure 7 A schematic diagram of another embodiment of the specific buffer structure provided by the present invention;

[0034] Figure 8 This is a schematic diagram of another embodiment of the specific buffer structure provided by the present invention.

[0035] Figures 1-6 middle:

[0036] 1. Sheath assembly; 11. Sheath body; 111. Pressure relief hole; 112. Inner cavity; 12. First connector; 13. Second connector; 14. Third connector; 15. Fourth connector; 16. Push seal; 17. Overflow chamber;

[0037] 2. Handle assembly;

[0038] 3. Rotating assembly; 31. Moving part; 311. Functional component; 312. Base; 32. Cable; 33. Drive shaft; 34. Drive shaft connector; 35. Electrical connector; 36. Rotating interface;

[0039] 4. Pushing component; 41. Front push tube; 42. Rigid tube; 43. Pushing seat; 44. Intermediate sleeve; 45. Rotating sealing ring;

[0040] 5. Buffer structure; 51. Buffer cavity. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. In the specific embodiments, the distal end refers to the part of the corresponding component that is farther from the operator, typically the end where the component enters the patient's body or surgical area. The proximal end is the part of the corresponding component that is closer to the operator, typically the end that the operator holds or manipulates. For a single component, the end closer to the operator is the proximal end, and the end farther from the operator is the distal end. For example, although the proximal and distal ends of the buffer cavity mentioned in this application are both located outside the patient's body, for a single buffer cavity, to distinguish its structure, those skilled in the art will understand that the end closer to the operator along the catheter axis is the proximal end, and the end farther from the operator is the distal end. Furthermore, the end closest to the operator is the proximal end, and the end farthest from the operator is the distal end. Unless otherwise specified, the following description should be followed preferentially and will not be repeated.

[0043] In addition, it should be noted that the connections mentioned in this application include both direct connections between systems, components, and parts, and indirect connections between systems, components, and parts through a medium. Those skilled in the art should not interpret this as a limitation but should adapt it according to specific needs, and none of them exceed the protection scope of this application.

[0044] The core of this invention is to provide an interventional catheter that, by setting a buffer cavity, compensates for the change in the effective volume of the sheath body caused by the movement of the core within the sheath body. This allows the buffer cavity to store the liquid medium flowing out of the sheath body, or to replenish newly generated cavities within the sheath body, thereby preventing liquid medium leakage or external gas ingress at the sheath body's interface. Simultaneously, it solves the problem of increased resistance to movement of treatment or detection components due to pressure changes within the sheath body, increases the displacement consistency between the treatment or detection components and the pusher seat, and thus improves the detection accuracy and service life of the device.

[0045] like Figure 1 As shown, in the interventional catheter, the functional component 311 that performs the function of treatment or detection can be connected to the connector. The rotation and push-pull of the catheter controller can drive the rotation and extension of the functional component 311. The function of the drive shaft 33 is to transmit the torque or push-pull force of the proximal end of the connector to the distal end of the core.

[0046] like Figure 2As shown, for some reusable interventional catheters, the volume of the liquid medium in the catheter's sealed environment needs to be constant. The gap between the core (including functional component 311, drive shaft 33, and cable 32) and the inner wall of the sheath body 11 is small. However, with the movement of the core, especially its telescopic movement, the physical conditions such as the length and volume of the core in the sealed environment change. This requires a fixed amount of liquid medium to meet the needs of a catheter sealed environment with an indefinite volume. Based on the characteristic that the liquid medium is difficult to compress, the mismatch between the volume of the liquid medium and the volume of the catheter sealed environment can easily cause a sharp rise and fall in pressure, which can lead to external gas causing bubbles to be distributed near the functional component 311 or causing liquid medium leakage, making it difficult to reuse.

[0047] Based on the above solutions, please refer to Figures 3-6 This application provides an interventional catheter, including

[0048] The sheath body 11 has a distally closed inner cavity 112, which is elongated.

[0049] The core, having a functional component 311 at its distal end for treating or detecting tissue, is fitted within the inner cavity 112;

[0050] A connector is attached to the proximal end of the core and has an overflow cavity communicating with the proximal end of the inner cavity 112;

[0051] A buffer structure 5 is attached to the sheath body 11 or the connector. A buffer cavity 51 is provided inside the buffer structure 5. At least one set of pressure relief holes 111 for connecting the two is provided between the buffer cavity 51 and the inner cavity 112 of the sheath body 11. Alternatively, at least one set of pressure relief holes 111 for connecting the two is provided between the buffer cavity 51 and the connector.

[0052] in,

[0053] The sheath body 11 or the connector is provided with a pressure relief hole 111 that communicates with the buffer cavity 51. The gap and the overflow cavity form a first flow channel, and the pressure relief hole and the buffer cavity form a second flow channel. The first flow channel and the second flow channel communicate with each other and are set at an angle.

[0054] It should be noted that the overflow cavity mentioned above refers to a cavity in the connector that communicates with the buffer cavity 51. This does not mean that it is isolated or cut off from the outside, but rather that the overflow cavity has no direct fluid exchange or flow relationship with other cavities in the conduit. Figure 3-6As shown, the proximal end of the overflow cavity may have other cavities or liquid channels, such as liquid medium carried inside the drive shaft. However, during the process of the functional component 311 being pushed to rotate and / or move, the effective volume (volume available for liquid medium filling) of other cavities or liquid channels will not be affected or the liquid medium therein will always remain full. There is no mismatch between the volume of liquid medium and the volume of the conduit's sealed environment. Thus, the cavity in the connector that is directly affected by the movement of the functional component is defined as the overflow cavity.

[0055] In some embodiments, a fixed amount of the liquid medium fills the first flow channel and the second flow channel; the buffer cavity 51 has an elastic wall, and the volume of the buffer cavity 51 can automatically expand or contract with changes in its internal pressure.

[0056] like Figure 5 As shown, the buffer structure 5 can be a thin-walled structure, with its distal end fixedly connected to the outer wall of the sheath body 11 and its proximal end fixedly connected to the distal end of the connector. The connection method can be adhesive bonding, welding or mechanical connection.

[0057] Furthermore, the buffer cavity 51 of the buffer structure 5 encloses the sheath body 11, and several sets of pressure relief holes 111 are provided on the tube wall of the sheath body 11 for connecting the buffer cavity 51 and the inner cavity 112 of the sheath body 11. When the pressure in the inner cavity 112 of the sheath body 11 increases, the liquid medium in the first flow channel can enter the buffer cavity 51 through the pressure relief holes 111. When the pressure in the inner cavity 112 of the sheath body 11 decreases to a negative pressure, the liquid medium in the buffer cavity 51 can enter the first flow channel through the pressure relief holes 111, thereby achieving the effect of constant internal pressure of the sheath body 11.

[0058] In some embodiments, such as Figure 6 As shown, the buffer structure 5 can be cylindrical, partially or completely wrapped around a structural member communicating with the sheath body 11. The structural member, or part of the structural member, is located at the position of the buffer cavity 51. The pressure relief hole 111 can be partially or completely located on the structural member of the connecting member, or the pressure relief hole 111 can be partially or completely located on the sheath body 11, as shown. Figure 7-8 As shown. More preferably, at least one pressure relief hole is located at the proximal end of the buffer cavity 51.

[0059] In some embodiments, the connector includes an overflow cavity, and the conduit further includes a push seal 16 and a push assembly 4. The push seal 16 is disposed at the proximal end of the overflow cavity and slides against the core. The distal end of the core passes through the overflow cavity and extends into the inner cavity 112.

[0060] The core extends into the inner cavity 112 and is driven by the pushing component 4 to move relative to the inner cavity 112. The core is driven to move by the pushing component 4.

[0061] In one specific embodiment, during manufacturing, the connector and the sheath assembly 1, which consists of the sheath body 11 and the connector, are fixed first. Liquid medium is injected into the gap between the inner cavity 112 and the core, the buffer cavity 51, and the overflow cavity through the proximal end of the sheath body 11. Subsequently, the rotating assembly 3, which consists of the moving part 31, the cable 32, the drive shaft 33, and the drive shaft connecting seat 34, is inserted through the proximal end of the sheath body 11 until the moving part 31 moves to the distal end of the sheath body 11.

[0062] The moving part 31 includes a functional component 311 and a base 312 for fixing the functional component 311. The two ends of the drive shaft 33 are connected to the base 312 and the drive shaft connecting seat 34 for transmitting axial force and torque.

[0063] Then, install the push assembly 4, which consists of the front push tube 41, the rigid tube 42 and the push seat 43. Finally, connect or electrically connect the rotating interface 36, the electrical connector 35 and the intermediate sleeve 44 to the corresponding positions of the conduit controller.

[0064] In some embodiments, the functional component 311 is an ultrasonic probe.

[0065] In some embodiments, a fixed amount of liquid medium is pre-filled to fill the first flow channel and the second flow channel. The outer wall of the buffer cavity 51 is an elastic wall, and the volume of the buffer cavity 51 can expand or contract as its internal pressure changes, thereby maintaining a dynamic match between the volume of the liquid medium and the sealed environment of the conduit.

[0066] In some embodiments, the core is driven by the pushing component to move relative to the inner cavity 112, and the core is moved to change its portion located within the first flow channel, thereby changing the volume of the liquid medium within the first flow channel, wherein...

[0067] When the functional component 311 moves toward the distal end near the inner cavity 112, the liquid medium flows from the first flow channel to the second flow channel and expands the buffer cavity 51 to increase the volume of the buffer cavity 51.

[0068] When the functional component 311 moves toward the distal end away from the inner cavity 112, the liquid medium flows from the second flow channel to the first flow channel and contracts the buffer cavity 51 to reduce the volume of the buffer cavity 51.

[0069] The outer wall of the buffer cavity 51 is preferably made of silicone material, which is relatively soft. When the buffer cavity 51 is filled with an excessive amount of liquid medium, it can expand to increase its own volume, or when the buffer cavity 51 discharges a large amount of liquid medium, it can contract to reduce its own volume, thereby making the pressure change inside the buffer cavity 51 smaller.

[0070] Furthermore, the flow of liquid medium in the pressure relief hole 111 causes the pressure in the inner cavity 112 of the sheath body 11 to be affected by the pressure in the buffer cavity 51, resulting in a small pressure fluctuation, thereby effectively preventing the leakage of liquid medium in the sheath body 11 or the entry of external gas into the first flow channel.

[0071] In some embodiments, the maximum expandable volume of the buffer cavity 51 is not less than the maximum value of the volume change of the liquid medium caused by the movement of the core in the first flow channel, or the maximum volume of the buffer cavity 51 is not less than the maximum value of the volume change of the liquid medium caused by the movement of the core in the first flow channel.

[0072] In actual operation, a portion of the moving part 31 and the drive shaft 33 are always within the inner cavity 112 of the sheath body 11. When they are pulled out, the actual change in the effective volume of the first flow channel is the change in the volume occupied by the drive shaft 33 entering or exiting. Therefore, the volume of liquid medium exchanged through the pressure relief hole 111 is equal to the volume of that portion of the drive shaft 33. Thus, the maximum expandable volume (volume change value) of the buffer cavity 51 should not be less than the volume of that portion of the liquid medium. If the initial volume of the buffer cavity 51 is close to 0, then the maximum volume of the buffer cavity 51 should not be less than the maximum value of the volume change of the liquid medium caused by the movement of the core within the first flow channel.

[0073] Taking the radius of the drive shaft 33 as r and the maximum stroke as L as an example, the maximum volume of liquid medium that needs to be exchanged caused by the movement of the moving part 31 is πr. 2 L, that is, the minimum or expandable volume of the buffer cavity 51, should be greater than or equal to πr. 2 L;

[0074] like Figure 3 As shown, a rigid tube 42 is provided at the far end of the push assembly 4, and the drive shaft 33 passes through the rigid tube 42. When the moving part 31 moves, the rigid tube 42 enters the inner cavity 112 of the sheath body 11. Therefore, the volume of liquid medium to be contained in the buffer cavity 51 is the volume occupied by the rigid tube 42 entering the inner cavity 112 of the sheath body 11.

[0075] Taking the radius of the rigid tube 42 as R and the maximum stroke as L as an example, the maximum volume of liquid medium to be exchanged caused by the movement of the moving part 31 is πR. 2L, that is, the minimum or expandable volume of the buffer cavity 51, should be greater than or equal to πR. 2 L;

[0076] Meanwhile, since the rigid tube 42 is immersed in liquid medium for a long time, in order to increase the service life of the equipment, the rigid tube 42 is preferably a corrosion-resistant tube, such as a stainless steel tube.

[0077] In some embodiments, the buffer structure 5 is arranged at the proximal end of the sheath body 11 or the distal end of the connector, the sheath body or the connector is provided with pressure relief holes, and at least one set of pressure relief holes 111 communicates with the proximal end of the buffer cavity 51.

[0078] like Figure 5 As shown, the buffer structure 5 is arranged at the proximal end of the sheath body 11, and at least one set of pressure relief holes 111 are provided to connect to the proximal end of the buffer cavity 51.

[0079] Its function is as follows: during production and processing, when liquid medium is added through the proximal end of the sheath body 11, the liquid medium enters the buffer chamber 51 through the pressure relief hole 111 under pressure, and the original gas in the buffer chamber 51 is discharged into the sheath body 11 through the pressure relief hole 111. The pressure relief hole 111 located at the proximal end of the buffer chamber 51 can fill the buffer chamber 51 with liquid medium, so that the gas in the buffer chamber 51 can be completely discharged, thereby avoiding the impact on the detection accuracy of the equipment caused by the residual gas in the pre-filled liquid medium.

[0080] In some embodiments, the buffer structure 5 may be designed to be transparent and made of a highly transparent material to facilitate observation of whether the internal gas has been completely discharged or to observe the liquid filling status of the buffer cavity during operation, and to understand whether there are air bubbles or air leaks.

[0081] In some embodiments, the inner wall of the buffer cavity 51 and / or the sheath body 11 is provided with an anti-corrosion layer to prevent the liquid medium from corroding the inner wall of the buffer cavity 51 and / or the sheath body 11.

[0082] During use, the buffer cavity 51 and the sheath body 11 are always filled with liquid medium. An anti-corrosion layer is provided on the inner wall of the buffer cavity 51 and / or the sheath body 11, which can effectively slow down the corrosion rate of the buffer cavity 51 and / or the sheath body 11, thereby extending the service life of the equipment.

[0083] In some embodiments, a connector is coaxially connected to the proximal end of the sheath body 11, a rigid tube 42 is slidably disposed inside the connector, and a push-seal member 16 for sealing with the outer wall of the rigid tube 42 is provided on the inner wall of the connector.

[0084] like Figure 3As shown, the proximal end of the sheath body 11 is an open end. Since the drive shaft 33 needs to move and / or rotate inside the sheath body 11, the diameter of the drive shaft 33 is smaller than the inner diameter of the sheath body 11. That is, the liquid medium inside the sheath body 11 will leak from the gap between the drive shaft 33 and the inner wall of the sheath body 11. Since the drive shaft 33 is a flexible shaft, it is difficult to seal it with the sheath body 11.

[0085] Therefore, by providing a connector at the proximal end of the sheath body 11 and coaxially sliding the rigid tube 42 outside the core, the rigid tube 42 slides synchronously with the core, thereby changing the effective volume within the overflow cavity. The rigid tube 42 only moves axially with the connector and does not rotate relative to it, and the rigid tube 42 will not bend. By adding the push seal 16, the sealing problem between the soft drive shaft 33 and the inner wall of the sheath body 11 during the pumping process can be solved.

[0086] like Figure 3 As shown, the connectors, from front to back, include a first connector 12, a second connector 13, a third connector 14, and a fourth connector 15. The first connector 12 is fixedly connected to the proximal end of the sheath body 11, and the cavity of the first connector 12 is coaxial and connected to the cavity of the sheath body 11. The second connector 13 is fixedly connected to the proximal end of the first connector 12, and the first part of the push seal 16 is fixedly disposed at the proximal end of the second connector 13. The second part of the push seal 16 is fixedly disposed at the distal end of the fourth connector 15. The third connector 14 is a sleeve structure that wraps around the proximal end of the second connector 13 and the distal end of the fourth connector 15, and also wraps around the push seal 16, making the second connector 13, the fourth connector 15, and the push seal 16 coaxial. The outer wall of the rigid tube 42 contacts and seals the inner wall of the push seal 16.

[0087] In some embodiments, the proximal end of the rigid tube 42 is coaxially fixed and connected to a push seat 43;

[0088] The drive shaft 33 passes through the push seat 43, and its near end is coaxially fixedly connected to the drive shaft connecting seat 34. The drive shaft connecting seat 34 and the push seat 43 are rotatably mounted relative to each other, and a rotating sealing ring 45 is provided between them.

[0089] like Figure 4 As shown, a push seat 43 is provided at the proximal end of the rigid tube 42, and a drive shaft connecting seat 34 is rotatably provided inside the push seat 43. The drive shaft connecting seat 34 is coaxially and fixedly connected to the drive shaft 33, and seals the end of the drive shaft 33. In addition, a rotating sealing ring 45 is added, which solves the sealing problem between the outer wall of the drive shaft 33 and the inner wall of the rigid tube 42 during the rotation of the drive shaft 33.

[0090] That is, by adding the push seal 16 and the rotating seal ring 45, the sealing problem of the proximal opening of the sheath body 11 is effectively solved when the soft drive shaft 33 is axially pulled and rotated.

[0091] In some embodiments, a front push tube 41 is also included, which is fixed to the push seat 43 and together they are slidably mounted with the connector, which is fixedly mounted with the handle (for gripping).

[0092] like Figure 3 and Figure 4 As shown, a front push tube 41 is provided inside the connector. The connector provides guidance for the front push tube 41 and the push seat 43, ensuring that the push seat 43, the rigid tube 42 and the drive shaft 33 can all be fed along the axis of the sheath body 11.

[0093] In some embodiments, an intermediate sleeve 44 is also included, the distal end of which is coaxially fixedly arranged with the push seat 43;

[0094] The intermediate sleeve 44 is coaxially rotatably provided with a rotating interface 36 and an electrical connector 35. The rotating interface 36 is coaxially fixedly connected to the drive shaft connecting seat 34, and the electrical connector 35 is electrically connected to the functional component 311 at the far end of the drive shaft 33 through a cable 32.

[0095] like Figure 4 As shown, an intermediate sleeve 44 is added to connect the pusher seat 43 and the pusher unit of the conduit controller. At the same time, a rotating interface 36 and an electrical connector 35 are provided inside, so that the rotating interface 36 and the electrical connector 35 can move axially synchronously with the pusher seat 43, so that the axial movement of the rigid tube 42, the drive shaft 33, and the cable 32 are synchronized.

[0096] In some embodiments, the radial dimension of the buffer cavity 51 gradually decreases from the proximal end to the distal end (e.g., Figure 5 (as shown), or, the buffer cavity 51 is spherical, ellipsoidal, or spindle-shaped (not shown), or, the buffer cavity 51 is arranged parallel to the first flow channel (e.g. Figure 6 (As shown).

[0097] In some embodiments, the wall thickness constituting the buffer cavity is 0.1mm-5mm. The wall thickness of the buffer cavity can be uniform or non-uniform.

[0098] In addition to the interventional catheters disclosed in the above embodiments, the present invention also provides an interventional catheter including the above-described interventional catheters. The structure of other parts of the interventional catheter is described in the prior art and will not be repeated here.

[0099] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0100] The interventional catheter and the interventional catheter provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An interventional catheter, characterized in that, include: The sheath body has a distally closed inner cavity, which is elongated. A core, the distal end of which has functional components for treating or detecting tissue, the core being fitted inside the cavity; A connector, connected to the proximal end of the core and having an overflow cavity communicating with the proximal end of the inner cavity; A buffer structure is attached to the sheath body or the connector, and the buffer structure has a buffer cavity. A fixed amount of liquid medium is pre-filled into the gap between the inner cavity and the core, the buffer cavity, and the overflow cavity; in, The sheath body or the connector is provided with a pressure relief hole communicating with the buffer cavity. The gap and the overflow cavity form a first flow channel. The pressure relief hole and the buffer cavity form a second flow channel. The first flow channel and the second flow channel are connected and set at an angle. A fixed amount of the liquid medium fills the first flow channel and the second flow channel; The buffer cavity has elastic walls, and its volume can automatically expand or contract according to changes in its internal pressure.

2. The interventional catheter according to claim 1, characterized in that, The maximum expandable volume of the buffer cavity is not less than the maximum value of the volume change of the liquid medium caused by the movement of the core within the first flow channel, or... The maximum volume of the buffer cavity is not less than the maximum value of the volume change of the liquid medium caused by the movement of the core in the first flow channel.

3. The interventional catheter according to claim 1, characterized in that, It also includes push seals and push components; The push seal is disposed at the proximal end of the overflow cavity and slides against the core, and the distal end of the core passes through the overflow cavity and extends into the inner cavity; The core extends into the inner cavity and is driven by the pusher assembly to move relative to the inner cavity.

4. The interventional catheter according to claim 3, characterized in that, The core is driven by the pushing component to move relative to the inner cavity. This movement of the core alters its position within the first flow channel, thereby changing the volume of the liquid medium within the first flow channel. When the functional component moves toward the distal end near the inner cavity, the liquid medium flows from the first flow channel to the second flow channel and expands the buffer cavity to increase the volume of the buffer cavity. When the functional component moves toward the distal end away from the inner cavity, the liquid medium flows from the second flow channel to the first flow channel and contracts the buffer cavity to reduce the volume of the buffer cavity.

5. The interventional catheter according to claim 3, characterized in that, The pushing component includes a rigid tube that is sleeved on the outside of the proximal end of the core; The rigid tube moves synchronously with the core and changes the portion of the rigid tube located within the first flow channel, thereby changing the volume of the liquid medium within the inner cavity; The maximum expandable volume of the buffer cavity or the maximum volume of the buffer cavity is V, where V ≥ πR. 2 L, where L is the maximum stroke of the rigid tube moving synchronously with the core, and R is the radius of the rigid tube.

6. The interventional catheter according to claim 1, characterized in that, The buffer cavity is arranged circumferentially around the first flow channel, and the sheath body or the connector is provided with pressure relief holes. At least one set of pressure relief holes is provided at the proximal end of the buffer cavity and communicates with the first flow channel.

7. The interventional catheter according to claim 1, characterized in that, The radial dimension of the buffer cavity gradually decreases from the proximal end to the distal end; or, the buffer cavity is spherical, ellipsoidal, or spindle-shaped; or, the buffer cavity is arranged parallel to the first flow channel. The wall thickness of the buffer cavity is 0.1mm-5mm.

8. The interventional catheter according to claim 1, characterized in that, The inner wall of the buffer cavity and / or the sheath body is provided with an anti-corrosion layer to prevent the liquid medium from corroding the inner wall of the buffer cavity and / or the sheath body.

9. The interventional catheter according to claim 1, characterized in that, The cushioning structure is made of silicone, and / or the cushioning structure is made of a highly transparent material.

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