Ultrasonic catheter structure

Abstract

The utility model belongs to the technical field of interventional catheters, and discloses an ultrasonic catheter structure. The ultrasonic catheter structure comprises a shell, an outer tube, a middle tube and an inner tube, the near end of the middle tube is inserted into the shell, the far end of the middle tube is inserted into the near end of the outer tube and can move along the outer tube, the near end of the inner tube penetrates into the outer tube and is inserted into the far end of the middle tube, the far end of the inner tube extends out of the outer tube, and the inner tube and the middle tube are arranged in a sealed mode. The elastic bag body is used for storing ultrasonic conduction liquid, is arranged on the shell and is communicated with the middle tube, and the elastic bag body is used for supplementing the ultrasonic conduction liquid into the middle tube or absorbing redundant ultrasonic conduction liquid in the middle tube. The ultrasonic catheter structure provided by the utility model can be directly used without emptying after being clinically taken out, the catheter is always filled with liquid and is kept in an air-free state, the emptying step in the clinical process is avoided, the operation is simple, and the operation time of a doctor is shortened.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of intervention catheter, especially to an ultrasonic catheter structure. BACKGROUND

[0002] The IVUS catheter needs to emit and receive ultrasonic waves to image under high-speed rotation. Since air has strong reflection and high acoustic attenuation, the ultrasonic waves cannot have air on the propagation path. In the prior art, a liquid injection port is usually arranged on the shell of the ultrasonic catheter structure. Before the catheter enters the human body, a mixed solution of physiological saline and heparin sodium is injected into the catheter through the liquid injection port to flush the inner cavity of the ultrasonic imaging catheter, so as to drive the air inside the ultrasonic imaging catheter. However, as the outer diameter of the ultrasonic imaging catheter becomes thinner and thinner, the emptying resistance during clinical use becomes larger and larger, and the emptying effect becomes worse, so it is necessary to repeatedly empty during clinical use to achieve good imaging effect. The air exhaust operation is complicated, which seriously delays the diagnosis process of the doctor.

[0003] Therefore, there is an urgent need to provide an ultrasonic catheter structure to solve the above problems. SUMMARY

[0004] The utility model discloses a kind of ultrasonic catheter structures, after clinical extraction, it can be directly used without emptying, avoid the emptying step in clinical process, easy to operate.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] The ultrasonic catheter structure comprises:

[0007] The shell, the outer tube, the middle tube and the inner tube, the proximal end of the middle tube is inserted into the shell, the distal end of the middle tube is inserted into the proximal end of the outer tube and can move along the outer tube, the proximal end of the inner tube penetrates into the outer tube and is inserted into the distal end of the middle tube, the distal end of the inner tube extends out of the outer tube, and the inner tube and the middle tube are sealed.

[0008] The elastic bag body for storing ultrasonic conducting liquid is arranged on the shell and communicates with the middle tube, and the elastic bag body is used to supplement the ultrasonic conducting liquid in the middle tube or absorb the excess ultrasonic conducting liquid in the middle tube.

[0009] As an optional solution, a connector is sleeved on the shell, the connector is provided with a communication port communicating with the middle tube, and one end of the elastic bag body is sealingly and fixedly connected with the communication port.

[0010] As an optional solution, one end of the elastic bag body is connected with the communication port by welding or bonding.

[0011] As an optional solution, the elastic capsule comprises a capsule body and a sealing structure, the ultrasonic conductive liquid is stored in the capsule body, and the sealing structure is in interference fit with the capsule body.

[0012] As an optional solution, the first sealing assembly further comprises:

[0013] A sealing plug is sleeved outside the inner tube;

[0014] A first sealing ring is sleeved on the inner tube and located between the sealing plug and the middle tube, one side of the first sealing ring abuts against the distal end surface of the middle tube, and the other side abuts against the end surface of the sealing plug, and the first sealing ring is used for sealing the gap between the inner tube and the middle tube;

[0015] A sealing sleeve is sleeved and tightly held outside the middle tube, the first sealing ring and the sealing plug.

[0016] As an optional solution, the sealing sleeve is a heat shrink tube.

[0017] As an optional solution, a first sealing connecting part is fixedly connected between the sealing sleeve and the middle tube, and the first sealing connecting part is used for sealing the gap between the sealing sleeve and the middle tube;

[0018] And / or, a second sealing connecting part is fixedly connected between the sealing sleeve and the sealing plug, and the second sealing connecting part is used for sealing the gap between the sealing sleeve and the sealing plug.

[0019] As an optional solution, the first sealing connecting part is formed by curing glue;

[0020] And / or, the second sealing connecting part is formed by curing glue.

[0021] As an optional solution, the second sealing assembly further comprises:

[0022] A sealing steel tube, one end of the sealing steel tube is located in the shell, and the other end of the sealing steel tube is inserted into the middle tube;

[0023] A sealing seat is fixedly arranged in the shell and sleeved outside the sealing steel tube, and the sealing seat is provided with a sealing groove near one end of the middle tube;

[0024] A second sealing ring is sleeved outside the sealing steel tube and accommodated in the sealing groove.

[0025] As an optional solution, the proximal end of the outer tube is externally provided with a threaded connecting member, and the distal end of the inner tube is externally provided with a matching member which is threadedly connected with the threaded connecting member, and the matching member is in sliding connection with the inner tube.

[0026] The utility model discloses beneficial effect:

[0027] The utility model provides an ultrasonic catheter structure, before factory, first through elastic sac body pre -injection ultrasonic transmission liquid to the middle tube, make ultrasonic transmission liquid fill the inner tube, the middle tube and elastic sac body, to empty the internal air, again seal elastic sac body, after entering human body, and ultrasonic transducer can be in the environment of filling ultrasonic transmission liquid through the action of in -push and back -off and complete imaging. When in -push, the middle tube moves to the far end along the outer tube and the inner tube, at this time, the space in the middle tube is smaller, and the excess ultrasonic transmission liquid in the middle tube is squeezed into the elastic sac body for absorption and storage. When back -off, the middle tube moves to the proximal end along the outer tube and the inner tube, that is, the middle tube gradually extends, and the internal space of the middle tube gradually increases. In this process, the ultrasonic transmission liquid in the elastic sac body is constantly supplemented into the middle tube. As can be seen, the ultrasonic catheter structure provided by the utility model can be directly used without emptying after clinical removal. The catheter is always filled with liquid, maintaining an air-free state, avoiding the emptying step in the clinical process, and being simple to operate, which shortens the operation time of doctors. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is the whole structure schematic diagram of the ultrasonic catheter structure provided by the utility model;

[0029] Figure 2 It is the cooperation schematic diagram of the shell and elastic sac body provided by the utility model;

[0030] Figure 3 It is the structure schematic diagram of the connection of the middle tube and the outer tube provided by the utility model;

[0031] Figure 4 It is the structure schematic diagram of the connection of the middle tube and the inner tube provided by the utility model;

[0032] Figure 5 It is the structure schematic diagram of the connection of the shell and the middle tube provided by the utility model.

[0033] In the drawing:

[0034] 1, shell;11, first stress release subassembly;

[0035] 2, outer tube;21, threaded connecting member;22, matching member;23, second stress release subassembly;

[0036] 3, middle tube;4, inner tube;41, distal sheath tube;42, sheath tube tip;

[0037] 5, elastic bag body; 51, bag body main body; 52, sealing structure;

[0038] 6, connecting head; 61, communication port;

[0039] 7, first sealing assembly; 71, sealing plug; 72, first sealing ring; 73, sealing sleeve; 74, first sealing connecting part; 75, second sealing connecting part;

[0040] 8, second sealing assembly; 81, sealing steel pipe; 82, sealing seat; 83, second sealing ring. DETAILED DESCRIPTION

[0041] The utility model will be described in further detail below in combination with the drawings and examples. It can be understood that the specific examples described here are only used to explain the utility model and are not limited to the utility model. In addition, it should be noted that only the parts related to the utility model are shown in the drawings for ease of description, not all the structures.

[0042] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood 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 of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0043] In the utility model, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0044] In the description of the embodiment, the terms "upper", "lower", "right", etc. orientation or position relationship is based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" are only used to distinguish in description and have no special meaning.

[0045] In this document, "distal" generally refers to the end of the ultrasound catheter structure that is farthest from the operator, and "proximal" is opposite "distal" and generally refers to the end of the ultrasound catheter structure that is closest to the operator.

[0046] As shown in Figures 1 to 4 , the embodiment provides an ultrasound catheter structure, which comprises a shell 1, an outer tube 2, a middle tube 3 and an inner tube 4, the proximal end of the middle tube 3 is inserted into the shell 1 and connected with the shell 1 through a first stress release assembly 11, the distal end of the middle tube 3 is inserted into the proximal end of the outer tube 2 and can move along the outer tube 2, the proximal end of the inner tube 4 penetrates into the outer tube 2 and is inserted into the distal end of the middle tube 3, the distal end of the inner tube 4 extends out of the outer tube 2 to form a distal sheath 41, the distal end of the distal sheath 41 is provided with a sheath tip 42, the inner tube 4 is connected with the outer tube 2 through a second stress release assembly 23, and the inner tube 4 and the middle tube 3 are sealingly arranged to prevent ultrasound transmission liquid from leaking out of the catheter. It should be noted that the first stress release assembly 11 and the second stress release assembly 23 both use the stress release assembly in the prior art, which will not be described here.

[0047] The ultrasound transducer rotates and withdraws in the inner tube 4, and emits and receives ultrasonic waves to the target tissue to image. Since air has strong reflection and high acoustic attenuation, the ultrasonic wave cannot have air on the transmission path. In the prior art, a liquid injection port is usually arranged on the shell 1 of the ultrasound catheter structure, and before the catheter enters the human body, a mixed solution of physiological saline and heparin sodium needs to be injected into the middle tube 3 through the liquid injection port to flush the inner cavity of the ultrasound imaging catheter, so as to drive the air inside the ultrasound imaging catheter. However, as the outer diameter of the ultrasound imaging catheter becomes thinner and thinner, the emptying resistance in the clinical use process becomes larger and larger, and the emptying effect becomes worse, so it is necessary to repeatedly empty in the clinical use process to achieve good imaging effect, and the air exhaust operation is complicated, which seriously delays the diagnosis process of the doctor.

[0048] In order to solve the above problems, as shown in Figure 1 and Figure 2 , the ultrasound catheter structure provided by the embodiment further comprises an elastic capsule 5 for storing ultrasound transmission liquid, the elastic capsule 5 is arranged on the shell 1 and communicates with the middle tube 3, and the elastic capsule 5 is used to supplement the ultrasound transmission liquid in the middle tube 3 or absorb the excess ultrasound transmission liquid in the middle tube 3.

[0049] The ultrasonic catheter structure provided by the embodiment is filled with the ultrasonic conducting liquid in the middle tube 3 in advance by the elastic capsule 5 before leaving the factory, so that the ultrasonic conducting liquid fills the inner tube 4, the middle tube 3 and the elastic capsule 5, to empty the internal air, and then the elastic capsule 5 is sealed. After entering the human body, the ultrasonic transducer can complete imaging by the inner pushing and retracting action in the environment filled with the ultrasonic conducting liquid. When the inner pushing, the middle tube 3 moves to the distal end along the outer tube 2 and the inner tube 4, at this time, the space in the middle tube 3 becomes smaller, and the excess ultrasonic conducting liquid in the middle tube 3 is squeezed into the elastic capsule 5 for absorption and storage. When the retracting, the middle tube 3 moves to the proximal end along the outer tube 2 and the inner tube 4, that is, the middle tube 3 gradually extends, and the internal space of the middle tube 3 gradually becomes larger. In this process, the ultrasonic conducting liquid in the elastic capsule 5 is continuously supplemented into the middle tube 3. As can be seen, the ultrasonic catheter structure provided by the embodiment can be directly used without emptying after being taken out in the clinic. The catheter is always filled with liquid, and keeps the state of no air, avoiding the emptying step in the clinical process, and the operation is simple, which shortens the operation time of the doctor, and the elastic capsule 5 can also buffer the thermal expansion and cold contraction caused by temperature changes in four seasons.

[0050] As shown in Figure 2 , the shell 1 is sleeved with a connecting head 6, the connecting head 6 is provided with a communication port 61 in communication with the middle tube 3, and one end of the elastic capsule 5 is sealingly and fixedly connected with the communication port 61. The elastic capsule 5 is installed on the communication port 61 of the connecting head 6, and the ultrasonic conducting liquid is supplemented into the middle tube 3 through the communication port 61, or the excess ultrasonic conducting liquid in the middle tube 3 is absorbed.

[0051] Further, one end of the elastic capsule 5 is connected with the communication port 61 by welding or bonding. In this way, the reliable connection of the elastic capsule 5 and the communication port 61 can be realized, and the sealing performance is good.

[0052] As shown in Figure 2 , the elastic capsule 5 includes a capsule main body 51 and a sealing structure 52, the capsule main body 51 stores the ultrasonic conducting liquid, and the sealing structure 52 is in interference fit with the capsule main body 51. Before leaving the factory, the ultrasonic conducting liquid is pre-filled into the middle tube 3 from the opening of the capsule main body 51 by vacuum filling or pressure filling, so that the ultrasonic conducting liquid fills the inner tube 4, the middle tube 3 and the capsule main body 51, to empty the internal air, and then the sealing part is inserted into the opening of the capsule main body 51 by pressure tongs or forging equipment to realize sealing.

[0053] Further, as shown in Figure 3 and Figure 4As shown, the ultrasonic catheter structure further comprises a first sealing assembly 7, which comprises a sealing plug tube 71, a first sealing ring 72 and a sealing sleeve 73. The sealing plug tube 71 is sleeved outside the inner tube 4. The first sealing ring 72 is sleeved on the inner tube 4 and located between the sealing plug tube 71 and the middle tube 3. One side of the first sealing ring 72 abuts against the distal end surface of the middle tube 3, and the other side abuts against the end surface of the sealing plug tube 71. The first sealing ring 72 is used to seal the gap between the inner tube 4 and the middle tube 3. The sealing sleeve 73 is sleeved and tightly held outside the middle tube 3, the first sealing ring 72 and the sealing plug tube 71. The inner ring of the first sealing ring 72 is tightly held against the inner tube 4, and the outer ring of the first sealing ring 72 is tightly held against the sealing sleeve 73, so as to seal the gap between the middle tube 3 and the inner tube 4, which is conducive to improving the sealing performance and preventing the ultrasonic transmission liquid from flowing into the outer tube 2 and leaking out of the catheter.

[0054] In this embodiment, the sealing sleeve 73 is a heat shrink tube. The sealing plug tube 71, the first sealing ring 72 and the middle tube 3 are heat shrunk together by using the heat shrink tube, which is simple in structure, easy to operate and good in sealing effect. In other optional embodiments, the sealing sleeve 73 can also be fixed with the sealing plug tube 71 and the middle tube 3 by welding or bonding and the like by using other pipe materials.

[0055] In an optional embodiment, as shown in Figure 4 , the sealing sleeve 73 and the middle tube 3 are fixedly connected with a first sealing connecting portion 74. The first sealing connecting portion 74 is used to seal the gap between the sealing sleeve 73 and the middle tube 3 and can fixedly connect the sealing sleeve 73 and the middle tube 3. The sealing sleeve 73 and the middle tube 3 are fixed and sealed by the first sealing connecting portion 74, which is conducive to further improving the sealing performance.

[0056] In an optional embodiment, as shown in Figure 4 , the sealing sleeve 73 and the sealing plug tube 71 are fixedly connected with a second sealing connecting portion 75. The second sealing connecting portion 75 is used to seal the gap between the sealing sleeve 73 and the sealing plug tube 71 and can fixedly connect the sealing sleeve 73 and the sealing plug tube 71. The sealing sleeve 73 and the sealing plug tube 71 are fixed and sealed by the second sealing connecting portion 75, which is conducive to further improving the sealing performance.

[0057] In an optional embodiment, the first sealing connecting portion 74 is formed by curing glue. The first sealing connecting portion 74 is formed by curing glue, which not only ensures the stable connection between the sealing sleeve 73 and the middle tube 3, but also achieves good sealing effect.

[0058] In an optional embodiment, the second sealing connecting part 75 is formed by curing glue. In the case of forming the second sealing connecting part 75 by curing glue, the sealing sleeve 73 and the sealing plug pipe 71 are connected stably, and better sealing effect is achieved.

[0059] In the assembling process, an appropriate amount of glue is applied to both ends of the sealing sleeve 73, and then the sealing sleeve 73 is sleeved outside the sealing plug pipe 71, the first sealing ring 72 and the middle pipe 3, and the glue is cured to form the first sealing connecting part 74 and the second sealing connecting part 75, which is convenient and fast.

[0060] In other optional embodiments, the first sealing connecting part 74 and the second sealing connecting part 75 can also be formed by curing hot melt material. It should be noted that the hot melt material includes but is not limited to a pipe material that can be melted. By heating the pipe material to melt and apply it between the sealing sleeve 73 and the middle pipe 3 and between the sealing sleeve 73 and the sealing plug pipe 71, and then curing, the first sealing connecting part 74 and the second sealing connecting part 75 can be formed, which can improve the connection stability of the sealing sleeve 73 and the middle pipe 3 and the sealing plug pipe 71 and ensure better sealing effect.

[0061] It should be noted that, as shown in Figure 4 , the outer diameter of the sealing sleeve 73 is smaller than the inner diameter of the outer pipe 2, so that the axial movement of the middle pipe 3 in the outer pipe 2 is not affected.

[0062] In an optional embodiment, as shown in Figure 4 , the outer diameter of the first sealing connecting part 74 gradually decreases in the direction from the middle part of the sealing sleeve 73 to the first sealing connecting part 74 along the axial direction of the sealing sleeve 73; and the outer diameter of the second sealing connecting part 75 gradually decreases in the direction from the middle part of the sealing sleeve 73 to the second sealing connecting part 75 along the axial direction of the sealing sleeve 73. Such arrangement helps to further reduce the friction when the middle pipe 3 moves, so that the middle pipe 3 is pushed more smoothly.

[0063] Further, as shown in Figure 5 , the ultrasonic catheter structure further comprises a second sealing assembly 8 connected with the ultrasonic system, the second sealing assembly 8 comprising a sealing steel pipe 81, a sealing seat 82 and a second sealing ring 83. One end of the sealing steel pipe 81 is located in the housing 1, and the other end is inserted into the middle pipe 3. The sealing seat 82 is fixed by welding or adhesive such as glue in the housing 1 and is sleeved outside the sealing steel pipe 81. The end of the sealing seat 82 close to the middle pipe 3 is provided with a sealing groove, and the second sealing ring 83 is sleeved outside the sealing steel pipe 81 and accommodated in the sealing groove. By using the above-mentioned second sealing assembly 8, liquid can be prevented from entering the ultrasonic system to damage the driving mechanism of the ultrasonic system.

[0064] Further, as shown in Figure 1 and Figure 3As shown, the proximal end of the outer tube 2 is provided with a threaded connecting piece 21, and the distal end of the inner tube 4 is provided with a cooperating piece 22 which is threadedly connected with the threaded connecting piece 21, and the cooperating piece 22 is slidingly connected with the inner tube 4. Specifically, the threaded connecting piece 21 is a bolt, and the cooperating piece 22 is a nut, the bolt is sleeved on the outer side of the outer tube 2 and fixedly connected with the outer tube 2, and the nut is sleeved on the outer side of the middle tube 3 and slidingly connected with the middle tube 3, when the bolt and the nut are screwed, the middle tube 3 can still move axially along the outer tube 2. The outer tube 2 and the middle tube 3 are detachably connected by the screwing of the bolt and the nut, not only the connection stability is high, but also the assembly and disassembly are easy, and the operability is stronger. Of course, in other embodiments, the threaded connecting piece 21 is a nut, and the cooperating piece 22 is a bolt, which can also achieve the above effects.

[0065] Obviously, the above embodiments of the utility model are only examples for clearly illustrating the utility model, and are not the limitation of the embodiments of the utility model. For ordinary skilled in the art, various obvious changes, re-adjustment and replacement can be made without departing from the protection scope of the utility model. Here, all the embodiments need not and cannot be exhausted. Any modification, equivalent replacement and improvement within the spirit and principle of the utility model should be included in the protection scope of the utility model claim.

Claims

1. An ultrasonic catheter structure, characterized by, It comprises: a shell (1), an outer tube (2), a middle tube (3) and an inner tube (4), the proximal end of the middle tube (3) is inserted into the shell (1), the distal end of the middle tube (3) is inserted into the proximal end of the outer tube (2) and can move along the outer tube (2), the proximal end of the inner tube (4) penetrates into the outer tube (2) and is inserted into the distal end of the middle tube (3), the distal end of the inner tube (4) extends out of the outer tube (2), and the inner tube (4) and the middle tube (3) are sealingly arranged; an elastic capsule (5) for storing ultrasonic conducting liquid, the elastic capsule (5) is arranged on the shell (1) and communicates with the middle tube (3), and the elastic capsule (5) is used to supplement the ultrasonic conducting liquid into the middle tube (3) or absorb the excess ultrasonic conducting liquid in the middle tube (3).

2. The ultrasonic catheter structure of claim 1, wherein, A connector (6) is sleeved on the shell (1), the connector (6) is provided with a communication port (61) communicating with the middle tube (3), and one end of the elastic capsule (5) is sealingly and fixedly connected with the communication port (61).

3. The ultrasonic catheter structure of claim 2, wherein, One end of the elastic capsule (5) is connected with the communication port (61) by welding or bonding.

4. The ultrasonic catheter structure of claim 1, wherein, The elastic capsule (5) comprises a capsule body (51) and a sealing structure (52), the ultrasonic conducting liquid is stored in the capsule body (51), and the sealing structure (52) is in interference fit with the capsule body (51).

5. The ultrasonic catheter structure of claim 1, wherein, It further comprises a first sealing assembly (7), the first sealing assembly (7) comprises: a sealing plug tube (71) sleeved outside the inner tube (4); a first sealing ring (72) sleeved on the inner tube (4) and located between the sealing plug tube (71) and the middle tube (3), one side of the first sealing ring (72) abuts against the distal end face of the middle tube (3), the other side abuts against the end face of the sealing plug tube (71), and the first sealing ring (72) is used to seal the gap between the inner tube (4) and the middle tube (3); a sealing sleeve (73) sleeved and tightly held outside the middle tube (3), the first sealing ring (72) and the sealing plug tube (71).

6. The ultrasonic catheter structure of claim 5, wherein, The sealing sleeve (73) is a heat shrink tube.

7. The ultrasonic catheter structure of claim 5, wherein, A first sealing connecting part (74) is fixedly connected between the sealing sleeve (73) and the middle tube (3), and the first sealing connecting part (74) is used to seal the gap between the sealing sleeve (73) and the middle tube (3); And / or, a second sealing connecting part (75) is fixedly connected between the sealing sleeve (73) and the sealing plug tube (71), and the second sealing connecting part (75) is used to seal the gap between the sealing sleeve (73) and the sealing plug tube (71).

8. The ultrasonic catheter structure of claim 7, wherein, The first sealing connecting part (74) is formed by glue curing; And / or, the second sealing connecting part (75) is formed by glue curing.

9. The ultrasonic catheter structure of any of claims 1-8, wherein, It further comprises a second sealing assembly (8), the second sealing assembly (8) comprises: a sealing steel tube (81), one end of the sealing steel tube (81) is located in the shell (1), and the other end is inserted into the middle tube (3); A sealing seat (82) is fixedly arranged in the shell (1) and sleeved outside the sealing steel pipe (81), and a sealing groove is arranged at one end of the sealing seat (82) close to the middle pipe (3); A second sealing ring (83) is sleeved outside the sealing steel pipe (81) and accommodated in the sealing groove.

10. The ultrasonic catheter structure of any of claims 1-8, wherein, A threaded connecting piece (21) is sleeved outside the proximal end of the outer pipe (2), a matching piece (22) is sleeved outside the distal end of the inner pipe (4) and threadedly connected with the threaded connecting piece (21), and the matching piece (22) is slidingly connected with the inner pipe (4).

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