Interventional catheter

Abstract

The invention discloses an interventional catheter and an interventional catheter, and relates to the technical field of medical instruments, in particular to a buffer structure, and a buffer cavity is formed in the buffer structure; according to the interventional catheter and the interventional catheter, the buffering cavity is arranged, so that when the core part moves in the sheathing canal body, the effective volume change of the sheathing canal body is made up by the volume of the buffering cavity, and redundant liquid media in the sheathing canal body can be stored by the buffering cavity; or the redundant cavity in the sheathing canal body is supplemented by the liquid medium in the buffer cavity, so that leakage of the liquid medium or entering of external gas at the interface of the sheathing canal body is prevented, and meanwhile, the problem that the movement resistance of a treatment or detection part is increased due to the change of the pressure in the sheathing canal body is solved; and the displacement consistency of the treatment or detection part and the pushing seat is improved, so that the detection precision and the service life of the equipment are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and more specifically, to an interventional catheter. Background Art

[0002] In an interventional catheter, in order to exert the treatment or detection function, it is usually necessary to drive the rotation and movement of the treatment or detection components. In a catheter environment with good sealing, due to the small gap between the core and the inner wall of the sheath body, when the core moves back, it is easy for the inside of the sheath body to be instantly in a vacuum state, and maintain the vacuum state for a certain period of time. At this time, the proximal end of the sheath body is prone to inhaling air due to negative pressure. At the same time, when the core moves forward, the internal pressure of the sheath body increases instantly, which can easily cause the liquid medium to leak from the interface of the sheath body. At the same time, due to the uneven pressure distribution, the drive at the proximal end of the catheter is difficult to accurately transmit to the distal treatment or detection components. The above adverse conditions are likely to affect the treatment and detection effects, reduce the life of the device, and even endanger the health of the patient.

[0003] In summary, how to solve the problem of air intake or liquid medium leakage caused by the sudden rise and fall of pressure during operation due to the movement of the core, as well as the problem of insufficient transmission consistency, are issues that urgently need to be solved by technical personnel in this field. Summary of the invention

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

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An interventional catheter comprises: a sheath body having an inner cavity with a closed distal end, the inner cavity being elongated; a core having a functional component for treating or detecting tissue at its distal end, the core being sleeved in the inner 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 attached to the sheath body or the connector, the buffer structure having a buffer cavity; a liquid medium, a fixed amount of the liquid medium being pre-filled in the gap between the inner cavity 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 connected to the buffer cavity, the gap and the overflow cavity constitute a first flow channel, the pressure relief hole and the buffer cavity constitute a second flow channel, the first flow channel is connected to the second flow channel and is arranged 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 an elastic wall, and the volume of the buffer cavity can automatically expand or contract as the internal pressure thereof changes.

[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 core moving in 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 core moving in the first flow channel.

[0012] In some embodiments, a push seal and a push assembly are also included; the push seal is arranged at the proximal end of the overflow chamber and the push seal is in sliding contact with the core, and the distal end of the core passes through the overflow chamber 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 assembly to move relative to the inner cavity, and the core is moved to change its portion located in the first flow channel, thereby changing the volume of the liquid medium in the first flow channel, wherein,

[0014] When the functional component moves toward the distal end close to 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 assembly includes a hard tube, and the hard tube is sleeved outside the proximal end of the core;

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

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

[0019] In some embodiments, the buffer cavity is circumferentially arranged around the first flow channel, and pressure relief holes are arranged on the sheath body or the connector, and at least one group of the pressure relief holes is arranged at the proximal end of the buffer cavity and communicated 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 shuttle-shaped, or the buffer cavity is arranged parallel to the first flow channel; the wall thickness of 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 buffer structure is made of silicone, and / or the buffer structure is made of a highly light-transmitting material.

[0023] Compared with the prior art, the interventional catheter provided by the present invention has at least the following beneficial effects:

[0024] 1. A buffer cavity is provided which is connected to the inner cavity of the sheath body and is arranged at an angle to store the liquid medium flowing out of the first flow channel or to supplement the insufficient liquid medium in the first flow channel, thereby balancing the pressure in the inner cavity of the sheath body, solving the sudden rise and fall of the pressure in the first flow channel caused by the movement of the core in the sheath body, thereby avoiding the leakage of the 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 in the inner cavity of the sheath body is balanced, thereby avoiding the increase in core resistance caused by the change in internal pressure of the sheath body, thereby improving the displacement consistency between the treatment or detection component and the push seat, and improving the detection accuracy of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 It is a schematic diagram of the design scheme of the interventional catheter in the prior art;

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

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

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

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

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

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

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

[0035] Figure 1-Figure 6 middle:

[0036] 1. sheath tube assembly; 11. sheath tube body; 111. pressure relief hole; 112. inner cavity; 12. first connecting piece; 13. second connecting piece; 14. third connecting piece; 15. fourth connecting piece; 16. push seal; 17. overflow cavity;

[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 assembly; 41. Front pushing tube; 42. Hard tube; 43. Pushing seat; 44. Intermediate sleeve; 45. Rotating sealing ring;

[0040] 5. Buffer structure; 51. Buffer cavity. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] In order to make the technical personnel in this technical field better understand the present application scheme, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. For the distal end and proximal end in the specific embodiments, the distal end refers to the part of the corresponding component away from the operator, usually the end of the component entering the patient's body or the surgical area, and the proximal end is the part of the corresponding component close to the operator, usually the end held or operated by the operator. For a single component, the end closer to the operator is the proximal end, and the end farther away from the operator is the distal end. For example, the proximal end and the distal end of the buffer cavity mentioned in this application are located outside the patient's body as a whole, but for a single buffer cavity, in order to distinguish its structure, it can be understood by those skilled in the art that the end closer to the operator along the axial direction of the catheter is the proximal end, and the end farther away from the operator is the distal end. Further, the end closest to the operator is the proximal end, and the end farthest away from the operator is the distal end. In the following, if there is no special indication, it should be understood in accordance with the above records, and no further description will be given.

[0043] In addition, it should be noted that the connection mentioned in this application includes both direct connections between systems, components, and parts, and connections between systems, components, and parts through a medium, that is, indirect connections. Those skilled in the art should not understand this as a limitation but should adapt it according to specific needs, which does not exceed the scope of protection of this application.

[0044] The core of the present invention is to provide an interventional catheter. By setting a buffer cavity, when the core moves in the sheath body, the change in the effective volume of the sheath body caused by the movement of the core is compensated by the volume of the buffer cavity, so that the liquid medium flowing out of the sheath body can be stored in the buffer cavity, or the newly generated cavity in the sheath body is supplemented by the liquid medium in the buffer cavity, thereby preventing the leakage of liquid medium or the entry of external gas at the interface of the sheath body. At the same time, it solves the problem of increased movement resistance of the treatment or detection components caused by pressure changes in the sheath body, increases the displacement consistency of the treatment or detection components and the push seat, and thus improves the detection accuracy and service life of the equipment.

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

[0046] like Figure 2As shown, due to the need for a constant volume of liquid medium in the closed environment of some reusable interventional catheters, the gap between the core (including the functional component 311, the drive shaft 33, and the cable 32) and the inner wall of the sheath body 11 is relatively small. However, as the core moves, especially the telescopic movement, the physical conditions such as the length and volume of the core in the closed environment change, and a certain amount of liquid medium is required to meet the requirements of the closed environment of the catheter with an indefinite volume. Based on the characteristic that the liquid medium is difficult to be compressed, the mismatch between the volume of the liquid medium and the closed environment of the catheter can easily cause a sharp rise and fall in pressure, thereby causing external gas to cause bubbles to be distributed near the functional component 311 or causing the liquid medium to leak, making it difficult to reuse.

[0047] Based on the above scheme, please refer to Figure 3-Figure 6 The present application provides an interventional catheter, comprising

[0048] The sheath body 11 has an inner cavity 112 with a closed distal end, and the inner cavity 112 is elongated;

[0049] A core, the distal end of which has a functional component 311 for treating or detecting tissue, and the core is sleeved in the inner cavity 112;

[0050] A connecting member connected to the proximal end of the core and having 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 in the buffer structure 5, at least one set of pressure relief holes 111 for connecting the buffer cavity 51 and the inner cavity 112 of the sheath body 11 is provided between the buffer cavity 51 and the inner cavity 112 of the sheath body 11, or at least one set of pressure relief holes 111 for connecting the buffer cavity 51 and the connector 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 connected to the buffer cavity 51, the gap and the overflow cavity constitute a first flow channel, the pressure relief hole and the buffer cavity constitute a second flow channel, the first flow channel is connected to the second flow channel and is arranged at an angle.

[0054] It should be noted that the overflow cavity above means a cavity in the connector that is connected to the buffer cavity 51. This does not mean that it is separated or isolated from the outside, but that there is no direct liquid exchange or flow relationship between the overflow cavity and other cavities of the catheter. Figure 3-6As shown, the proximal end of the overflow cavity may have other cavities or liquid flow channels, such as liquid medium carried inside the drive shaft, but when the functional component 311 is pushed to rotate and / or move, the effective volume of other cavities or liquid channels (the volume available for filling with liquid medium) will not be affected or the liquid medium therein will always remain full, and there is no mismatch between the volume of the liquid medium and the volume of the closed environment of the catheter, thereby defining the cavity in the connector that is directly affected by the movement of the functional component 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 as the internal pressure changes.

[0056] like Figure 5 As shown, the buffer structure 5 may be a thin-walled structure, the distal end of which is fixedly connected to the outer wall of the sheath body 11, and the proximal end of which is fixedly connected to the distal end of the connector, and the connection method may be bonding, welding or mechanical connection;

[0057] The buffer cavity 51 of the buffer structure 5 wraps the sheath body 11, and a plurality of pressure relief holes 111 are arranged on the tube wall of the sheath body 11, which are used to connect 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 become 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 pressure inside the sheath body 11.

[0058] In some embodiments, Figure 6 As shown, the buffer structure 5 can be a circular tube, partially or completely wrapped on a structural member connected to 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 connector, or the pressure relief hole 111 can be partially or completely located on the sheath body 11, as shown in FIG. Figure 7-8 Further 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, the catheter 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 the push seal 16 is in sliding contact with the core, and 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 assembly 4 to move relative to the inner cavity 112 , and is driven by the pushing assembly 4 to move.

[0061] In a specific embodiment, during manufacturing, the connector and the sheath assembly 1 composed of the sheath body 11 and the connector are preferably fixed, and the liquid medium is poured 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; then, the rotating assembly 3 composed of the moving part 31, the cable 32, the driving shaft 33 and the driving 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. Both ends of the driving shaft 33 are connected to the base 312 and the driving shaft connecting seat 34 for transmitting axial force and torque.

[0063] Then, the push assembly 4 consisting of the front push tube 41, the hard tube 42 and the push seat 43 is installed. Finally, the rotation interface 36, the electrical connector 35, and the intermediate sleeve 44 are respectively connected or electrically connected to the corresponding positions of the catheter controller.

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

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

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

[0067] When the functional component 311 moves toward the distal end close to 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 a silicone material, which is relatively soft. When an excessive amount of liquid medium is filled into the buffer cavity 51, it can expand to increase its own volume, or when a large amount of liquid medium is discharged from the buffer cavity 51, it can shrink to reduce its own volume, thereby making the pressure change inside the buffer cavity 51 smaller;

[0070] Furthermore, through the flow of the liquid medium in the pressure relief hole 111, the pressure of the inner cavity 112 of the sheath body 11 is affected by the pressure in the buffer cavity 51, and also has a smaller pressure fluctuation, thereby effectively preventing the liquid medium in the sheath body 11 from leaking or external gas from entering 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 core moving 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 core moving in the first flow channel.

[0072] In the actual working process, the moving part 31 and part of the driving shaft 33 are always in the inner cavity 112 of the sheath body 11. When it twitches, the actual change in the effective volume of the first flow channel is the change in the occupied volume of the driving shaft 33 at the distal end entering or withdrawing. Therefore, the volume of the liquid medium exchanged through the pressure relief hole 111 is equal to the volume of this part of the driving shaft 33. Therefore, the maximum expandable volume (volume change value) of the buffer cavity 51 should not be less than the volume of this part of the liquid medium. For the case where the initial volume of the buffer cavity 51 is close to 0, 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 core moving in the first flow channel.

[0073] Taking the radius of the driving shaft 33 as r and the maximum pumping stroke as L as an example, the maximum volume of the liquid medium that needs to be exchanged due to the movement of the moving part 31 is πr 2 L, that is, the minimum volume 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 hard tube 42 is provided at the distal end of the push assembly 4, and the drive shaft 33 penetrates the hard tube 42. When the moving part 31 moves, the hard tube 42 enters the inner cavity 112 of the sheath body 11. Therefore, the volume of the liquid medium to be accommodated by the buffer cavity 51 is the volume occupied by the hard tube 42 entering the inner cavity 112 of the sheath body 11;

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

[0076] At the same time, since the hard pipe 42 is immersed in the liquid medium for a long time, in order to increase the service life of the equipment, the hard pipe 42 is preferably an anti-corrosion pipe, such as a stainless steel pipe.

[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, and the sheath body or the connector is provided with a pressure relief hole, and at least one group of pressure relief holes 111 is connected to 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 group of pressure relief holes 111 is provided to communicate with the proximal end of the buffer cavity 51;

[0079] Its function is that during production and processing, when liquid medium is added through the proximal end of the sheath body 11, the liquid medium enters the buffer cavity 51 through the pressure relief hole 111 under the action of pressure, and the original gas in the buffer cavity 51 is discharged into the sheath body 11 through the pressure relief hole 111. The buffer cavity 51 can be filled with liquid medium through the pressure relief hole 111 set at the proximal end of the buffer cavity 51, so that the gas in the buffer cavity 51 is completely discharged, thereby avoiding the influence of internal gas retained during pre-injection of liquid medium on the detection accuracy of the equipment.

[0080] In some embodiments, the buffer structure 5 can be designed to be transparent and made of a highly light-transmitting material to facilitate observation of whether the internal gas is completely discharged or the liquid filling condition in the buffer cavity during operation to understand whether bubbles are generated or air leaks occur.

[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 of the product, the buffer cavity 51 and the sheath body 11 are always filled with liquid medium. An anti-corrosion layer is arranged 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 hard tube 42 is slidably disposed in the connector, and a push seal 16 for sealing with the outer wall of the hard tube 42 is disposed 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 in 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 in the sheath body 11 will leak from the gap between the drive shaft 33 and the inner wall of the sheath body 11. The drive shaft 33 is a soft shaft, and it is difficult to seal it with the sheath body 11.

[0085] Therefore, a connector is provided at the proximal end of the sheath body 11, and the hard tube 42 is coaxially slidably provided outside the core. The hard tube 42 slides synchronously with the core, so that the effective volume in the overflow cavity changes. The hard tube 42 only moves axially with the connector without relative rotation, and the hard tube 42 does not bend. By adding a 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 connecting parts include a first connecting part 12, a second connecting part 13, a third connecting part 14 and a fourth connecting part 15 from front to back, wherein the first connecting part 12 is fixedly connected to the proximal end of the sheath body 11, and the cavity of the first connecting part 12 is coaxial and connected to the cavity of the sheath body 11, the second connecting part 13 is coaxially fixedly connected to the proximal end of the first connecting part 12, and the proximal end of the second connecting part 13 is fixedly provided with a first part of a push seal 16, and the distal end of the fourth connecting part 15 is fixedly provided with a second part of the push seal 16, the third connecting part 14 is a sleeve structure, which respectively wraps the proximal end of the second connecting part 13 and the distal end of the fourth connecting part 15, and wraps the push seal 16, so that the second connecting part 13, the fourth connecting part 15 and the push seal 16 are coaxial; the outer wall of the hard tube 42 is in contact and sealed with the inner wall of the push seal 16.

[0087] In some embodiments, the proximal end of the hard tube 42 is coaxially fixed and connected with a pushing seat 43;

[0088] The driving shaft 33 passes through the pushing seat 43, and its proximal end is coaxially fixedly connected with the driving shaft connecting seat 34. The driving shaft connecting seat 34 and the pushing seat 43 are relatively rotatably installed, and a rotating sealing ring 45 is arranged between the two.

[0089] like Figure 4 As shown, a push seat 43 is provided at the proximal end of the hard tube 42, and a drive shaft connecting seat 34 is rotatably provided in the push seat 43. The drive shaft connecting seat 34 is coaxially fixedly connected with the drive shaft 33 and seals the end of the drive shaft 33. 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 hard tube 42 during the rotation process.

[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 when the soft drive shaft 33 is axially pulled and rotated is effectively solved.

[0091] In some embodiments, it also includes a front push tube 41, the front push tube 41 and the push seat 43 are fixed to each other, and they are slidably installed together with the connecting member, and the connecting member is fixedly installed with the handle (for holding);

[0092] like Figure 3 and Figure 4 As shown, a front push tube 41 is arranged in the connecting member, and the connecting member provides guidance for the front push tube 41 and the push seat 43 to ensure that the push seat 43, the hard tube 42 and the driving shaft 33 can all be fed along the axis of the sheath body 11.

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

[0094] A rotation interface 36 and an electrical connector 35 are coaxially rotatably provided in the middle sleeve 44. The rotation interface 36 is coaxially fixedly connected to the drive shaft connection seat 34. The electrical connector 35 is electrically connected to the functional component 311 at the far end of the drive shaft 33 through the cable 32.

[0095] like Figure 4 As shown, an intermediate sleeve 44 is added to connect the pushing seat 43 and the pushing unit of the catheter controller. At the same time, a rotating interface 36 and an electrical connector 35 are internally rotated, so that the rotating interface 36 and the electrical connector 35 can move axially synchronously with the pushing seat 43, that is, the axial movement of the hard tube 42 and the driving shaft 33 and the cable 32 is 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 shuttle-shaped (not shown), or, the buffer cavity 51 is arranged parallel to the first flow channel (as shown Figure 6 as shown).

[0097] In some embodiments, the wall thickness of the buffer cavity is 0.1 mm-5 mm, and 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 interventional catheter. For the structures of other parts of the interventional catheter, please refer to the prior art and will not be described in detail herein.

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

[0100] The above is a detailed introduction to the interventional catheter and interventional catheter provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An interventional catheter, characterized in that: include: The sheath body has an inner cavity with a closed distal end, and the inner cavity is elongated; A core, the distal end of which has a functional component for treating or detecting tissue, and the core is sheathed in the inner cavity; A connecting member 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, attached to the sheath body or the connector, the buffer structure having a buffer cavity; A liquid medium, a fixed amount of which 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 connected to the buffer cavity, the gap and the overflow cavity constitute a first flow channel, the pressure relief hole and the buffer cavity constitute a second flow channel, the first flow channel is connected to the second flow channel and is arranged at an angle.

2. The interventional catheter according to claim 1, characterized in that: A fixed amount of the liquid medium fills the first flow channel and the second flow channel; The buffer cavity has an elastic wall, and the volume of the buffer cavity can automatically expand or contract as the internal pressure thereof changes.

3. The interventional catheter according to claim 2, 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 core moving in 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 core moving in the first flow channel.

4. The interventional catheter according to claim 1, characterized in that: Also included are a push seal and a push assembly; The push seal is arranged at the proximal end of the overflow cavity and the push seal is in sliding contact with 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 pushing assembly to move relative to the inner cavity.

5. The interventional catheter according to claim 4, characterized in that: The core is driven by the pushing assembly to move relative to the inner cavity, and the core is moved to change its portion located in the first flow channel, thereby changing the volume of the liquid medium in the first flow channel, wherein: When the functional component moves toward the distal end close to 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.

6. The interventional catheter according to claim 4, characterized in that: The pushing assembly comprises a hard tube, and the hard tube is sleeved outside the proximal end of the core; The hard tube moves synchronously with the core and changes the portion of the hard tube located in the first flow channel, thereby changing the volume of the liquid medium in the inner cavity; The maximum expandable volume of the buffer cavity or the maximum volume of the buffer cavity is V, V ≥ πR 2 L, wherein L is the maximum stroke of the hard tube and the core moving synchronously, and R is the radius of the hard tube.

7. The interventional catheter according to claim 1, characterized in that: The buffer cavity is circumferentially arranged around the first flow channel, and pressure relief holes are arranged on the sheath body or the connecting piece. At least one group of the pressure relief holes is arranged at the proximal end of the buffer cavity and communicated with the first flow channel.

8. 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 shuttle-shaped, or the buffer cavity is arranged parallel to the first flow channel; The wall thickness of the buffer cavity is 0.1 mm to 5 mm.

9. 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 for preventing the liquid medium from corroding the inner wall of the buffer cavity and / or the sheath body.

10. The interventional catheter according to claim 1, characterized in that: The buffer structure is made of silica gel, and / or the buffer structure is made of a highly light-transmitting material.

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