Balloon catheter

Abstract

The application relates to the field of interventional surgical instruments, in particular to a balloon catheter, which comprises a catheter and a balloon arranged in the catheter, the balloon comprising a first balloon body and a second balloon body which can be deflated and inflated, the first balloon body and the second balloon body are isolated from each other and at least partially overlap along the catheter axis to form a measuring section for crossing and adapting to a tissue defect; the catheter is defined with independent first and second perfusion channels; the first perfusion channel is in communication with the inner cavity of the first balloon body and is used for perfusing gas into the first balloon body; the second perfusion channel is in communication with the inner cavity of the second balloon body and is used for perfusing liquid contrast agent into the second balloon body. Due to the high compressibility of the gas, the first balloon body can be deformed more under the same pressure, so that the balloon can not only easily form a clear "waist sign", but also slow down the tension growth rate, ensure that the balloon can stably adhere to the defect edge after being inflated, and safely realize accurate measurement of the defect size.

Description

Technical Field

[0001] This application relates to the field of interventional surgical instruments, specifically to a balloon catheter. Background Technology

[0002] Atrial septal defect (ASD) is a common congenital heart disease. Interventional closure, which involves puncturing the atrial septum and delivering an occluder to close the defect, has become the mainstream treatment. In this procedure, accurate preoperative measurement of the ASD's expansion diameter is crucial for selecting the appropriate occluder and ensuring surgical success. Currently, the balloon measurement method is commonly used clinically. This involves delivering a balloon catheter to the ASD, injecting diluted contrast agent into the balloon under X-ray fluoroscopy, causing the balloon to form a "waist sign" (i.e., a waist-shaped structural feature where balloon expansion is restricted by the atrial septum tissue) at the defect site. The defect diameter is then estimated by measuring relevant parameters (such as balloon pressure and diameter).

[0003] However, measurement balloons typically use full contrast agent perfusion. When the perfusion volume exceeds the rated volume, the internal pressure of the balloon increases significantly, increasing the supporting force of the balloon on the surrounding tissues, causing tissue expansion and making the "waist sign" less obvious, thus affecting measurement accuracy. If perfusion continues, there is also a risk of tearing the atrial septum due to excessive supporting pressure, resulting in larger defects, thus raising concerns about safety. Utility Model Content

[0004] This application aims to address the safety issues of balloon catheters in measuring atrial septal defects in related technologies by providing a new balloon catheter.

[0005] One embodiment provides a balloon catheter, comprising:

[0006] catheter;

[0007] And a balloon disposed in the catheter, the balloon comprising a collapsible and inflatable first balloon body and a second balloon body, the first balloon body and the second balloon body being isolated from each other and at least partially overlapping along the axial direction of the catheter to form a measurement segment for traversing and accommodating tissue defects;

[0008] The catheter defines a separate first perfusion channel and a second perfusion channel;

[0009] The first infusion channel is connected to the inner cavity of the first balloon body and is used to infuse gas into the first balloon body;

[0010] The second perfusion channel is connected to the inner cavity of the second balloon body and is used to perfuse liquid contrast agent into the second balloon body.

[0011] In one embodiment, the first balloon and the second balloon are arranged in a nested structure, with the second balloon sleeved on the outside of the first balloon.

[0012] In one embodiment, the first balloon is located in the middle of the inner cavity of the second balloon along the axial direction of the catheter, and the walls of the first balloon and the second balloon are spaced apart.

[0013] In one embodiment, the first infusion channel and the second infusion channel are disposed inside the catheter;

[0014] The first infusion channel further includes at least one gas infusion hole disposed on the wall of the catheter for connecting the inner cavity of the first balloon and the first infusion channel;

[0015] The second infusion channel further includes at least one liquid infusion hole disposed on the wall of the catheter for connecting the inner cavity of the second balloon and the second infusion channel.

[0016] In one embodiment, the gas infusion port includes a first gas infusion port and a second gas infusion port, wherein the first gas infusion port is disposed near the proximal end of the first balloon body, and the second gas infusion port is disposed near the distal end of the first balloon body;

[0017] And / or, the liquid infusion port includes a first liquid infusion port and a second liquid infusion port, wherein the first liquid infusion port is disposed near the proximal end of the second balloon body, and the second liquid infusion port is disposed near the distal end of the second balloon body.

[0018] In one embodiment, the proximal and / or distal end of the first balloon includes a first conical transition section. When the first balloon is inflated, a first conical transition region with radially varying dimensions is formed within the first conical transition section. The gas infusion port is arranged corresponding to the tip of the first conical transition section to communicate with the first conical transition region; and / or,

[0019] The proximal and / or distal ends of the second balloon body include a second conical transition section. When the second balloon body is inflated, a second conical transition zone with radially varying dimensions is formed within the second conical transition section. The liquid infusion port is arranged corresponding to the tip of the second conical transition section to communicate with the second conical transition zone.

[0020] In one embodiment, the gas injection port and the liquid injection port are arranged at intervals along the circumference of the conduit.

[0021] In one embodiment, the gas injection port and the liquid injection port are located on opposite sides of the conduit in the circumferential direction.

[0022] In one embodiment, the catheter is further provided with a threading channel for threading a guidewire, and the first irrigation channel and the second irrigation channel are arranged around the threading channel.

[0023] In one embodiment, the balloon catheter further includes an interface element connected to the catheter, comprising:

[0024] The first injection port is connected to the first injection channel and is used to connect to the gas input device for gas input.

[0025] The second infusion port is connected to the second infusion channel and is used to connect to the liquid contrast agent input device for liquid input.

[0026] And a guidewire insertion interface, which is arranged along the axial direction of the catheter and communicates with the guidewire insertion channel for guidewire insertion.

[0027] According to the balloon catheter of the above embodiment, by setting a first balloon body and a second balloon body that are isolated from each other and at least partially overlap along the catheter axis, and with independent first and second perfusion channels, gas and liquid contrast agents are perfused respectively. During the test, a rated volume of liquid contrast agent can be perfused into the second balloon body first, and then gas can be perfused into the first balloon body. Since the perfused gas has much better compressibility than liquid contrast agent, the gas is compressed after the perfusion volume exceeds the rated volume, which helps to improve the elasticity of the balloon. Compared with a balloon that is fully perfused with liquid contrast agent, the tension increases more slowly, which helps to avoid the balloon exerting excessive support force on the atrial septal defect tissue, reduces the risk of expansion and tearing of the contacted atrial septal tissue, and helps to improve the safety in atrial septal defect measurement.

[0028] Furthermore, the liquid contrast agent infused into the second balloon ensures clear imaging under X-ray equipment, making the "waist sign" visible. Simultaneously, the elastic buffering effect of the gas within the first balloon ensures that the entire measurement segment gently adapts to the true boundary of the defect, rather than forcibly expanding the tissue. This results in a "waist sign" that more accurately reflects the actual diameter of the atrial septal defect, providing more precise and reliable data for selecting an appropriate occluder. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a balloon catheter according to one embodiment;

[0030] Figure 2 This is a schematic diagram of the distal end of a balloon catheter according to one embodiment;

[0031] Figure 3 This is a schematic diagram of the distal end of a balloon catheter according to another embodiment;

[0032] Figure 4 This is a schematic diagram of the proximal end of a balloon catheter according to one embodiment.

[0033] In the diagram, 10 is the conduit; 11 is the first infusion channel; 111 is the gas infusion port; 1111 is the first gas infusion port; 1112 is the second gas infusion port; 12 is the second infusion channel; 121 is the liquid infusion port; 1211 is the first liquid infusion port; 1212 is the second liquid infusion port; and 13 is the threading channel. 20. Balloon; 21. First balloon body; 211. First conical transition section; 212. First conical transition zone; 22. Second balloon body; 221. Second conical transition section; 222. Second conical transition zone; 23. Measurement section; 30. Interface component; 31. First injection interface; 32. Second injection interface; 33. Threading interface. Detailed Implementation

[0034] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0035] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0036] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0037] The terms "proximal" and "distal" used in this article are conventional medical terms. For the instrument to be operated on, the proximal end is the end closer to the operator, and the distal end is the end furthest from the operator; it is usually the end that enters the patient's body first. For more information on proximal and distal ends, please refer to [link to relevant documentation]. Figure 1 The displayed location.

[0038] In this embodiment, by using gas-liquid co-perfusion to infuse the first balloon body 21 and the second balloon body 22, the compressibility of the gas is used to improve the overall elasticity of the balloon 20, making it easier for the measuring segment 23 to form a clear "waist sign" and reducing the risk of tissue expansion and tearing, which helps to improve the safety and accuracy of the balloon catheter in the detection of atrial septal defects.

[0039] In one embodiment, please refer to Figure 1 and Figure 2 The balloon catheter includes a catheter 10 and a balloon 20. The balloon 20 is fixedly disposed in the distal region of the catheter 10. The balloon 20 includes a collapsible and inflatable first balloon body 21 and a second balloon body 22. The first balloon body 21 and the second balloon body 22 are mutually isolated independent cavities, and they are at least partially overlapping along the axial direction of the catheter 10. The catheter 10 defines independent first perfusion channels 11 and second perfusion channels 12. The first perfusion channel 11 is separately connected to the inner lumen of the first balloon body 21 and is specifically used for perfusing gas into the first balloon body 21. The gas used may include air, nitrogen, etc. The second perfusion channel 12 is separately connected to the inner lumen of the second balloon body 22 and is specifically used for perfusing a liquid contrast agent into the second balloon body 22. The liquid contrast agent is a clinically commonly used diluted contrast agent that can be clearly visualized under X-ray fluoroscopy and other radiation equipment, thereby visually presenting the contact morphology between the balloon 20 and the atrial septal defect tissue, providing a visual basis for measurement.

[0040] The overlapping area of ​​the first balloon body 21 and the second balloon body 22 constitutes a measurement segment 23 for traversing and adapting to the atrial septal defect. Due to the high compressibility of the gas, the first balloon body 21 can deform more under the same pressure, thereby improving the elasticity of the balloon 20. During the test, a rated volume of liquid contrast agent can be injected into the second balloon body 22 first, and then gas can be injected into the first balloon body 21. After the injected volume exceeds the rated volume, the gas is compressed, which makes it easier for the balloon 20 to form a clear "waist sign" and slows down the rate of tension increase. This ensures that the balloon 20 can stably fit the edge of the defect after inflation, which helps to safely and accurately measure the size of the defect.

[0041] In one embodiment, please refer to Figure 1 and Figure 2The first balloon body 21 and the second balloon body 22 are arranged in an inner and outer nested structure. The second balloon body 22 is fitted outside the first balloon body 21. The inner and outer nested structure design can maximize the overlap area of ​​the two balloon bodies, ensuring that the measurement segment 23 can fully cover the defect. At the same time, the nested structure is compact, reducing the space occupied by the balloon 20 in the body, reducing interference with surrounding tissues, and improving the convenience of interventional operation.

[0042] In one embodiment, please refer to Figure 1 and Figure 2 The first balloon 21 is located in the middle of the inner lumen of the second balloon 22 along the axial direction of the catheter 10, and the walls of the first balloon 21 and the second balloon 22 are spaced apart. The spaced area provides sufficient filling space for the liquid contrast agent in the second balloon 22, ensuring that the contrast agent can be evenly distributed on the outside of the first balloon 21, making the imaging of the "waist sign" more complete and accurate, avoiding measurement deviations caused by uneven distribution of contrast agent. At the same time, the first balloon 21 arranged in the middle can provide uniform support for the second balloon 22, ensuring the morphological stability of the balloon 20 after it is fully inflated.

[0043] In other embodiments, the first balloon body 21 and the second balloon body 22 may also be arranged in other ways that at least partially overlap; for example, please refer to: Figure 3 Both the first balloon body 21 and the second balloon body 22 are positioned distal to the catheter 10, with the second balloon body 22 being closer to the distal end of the catheter 10 than the first balloon body 21. The distance between the proximal end of the second balloon body 22 and the distal end of the catheter 10 is greater than the distance between the distal end of the first balloon body 21 and the distal end of the catheter 10, but less than the distance between the proximal end of the first balloon body 21 and the distal end of the catheter 10, so that the proximal portion of the second balloon body 22 overlaps with the distal portion of the first balloon body 21, resulting in a balloon 20 arrangement along the axial direction of the catheter 10 with "anterior-posterior staggered layers and mid-section overlap". The overlapping section constitutes the measurement segment 23 used to cross and adapt to the atrial septal defect, while the non-overlapping portions serve as the distal extensions of the first balloon body 21 and the proximal extensions of the second balloon body 22, respectively. In some cases, the distal extension of the first balloon body 21 and the proximal extension of the second balloon body 22 can also play a positioning and anchoring role by abutting against the atrial wall, avoiding displacement of the balloon 20 during measurement. Furthermore, due to the low tension characteristics of the gas filling, it is not easy to compress the atrial tissue, which helps to ensure safe use.

[0044] In one embodiment, please refer to Figure 1 and Figure 2The first perfusion channel 11 and the second perfusion channel 12 are both located inside the catheter 10. The first perfusion channel 11 also includes at least one gas perfusion port 111 located on the wall of the catheter 10. The gas perfusion port 111 connects the inner cavity of the first balloon 21 and the first perfusion channel 11, allowing gas to smoothly enter the first balloon 21 through the first perfusion channel 11 and the gas perfusion port 111. Similarly, the second perfusion channel 12 includes at least one liquid perfusion port 121 located on the wall of the catheter 10. The liquid perfusion port 121 connects the inner cavity of the second balloon 22 and the second perfusion channel 12, ensuring that the liquid contrast agent can be stably injected into the second balloon 22. It should be noted that the number of gas perfusion ports 111 and liquid perfusion ports 121 can be set to one or more according to actual needs. In practical applications, the perfusion ports can also be replaced by other connecting structures such as perfusion tubes, as long as effective communication between the perfusion channel and the inner cavity of the balloon 20 can be achieved.

[0045] In one embodiment, please refer to Figure 1 and Figure 2 The gas infusion port 111 includes a first gas infusion port 1111 and a second gas infusion port 1112. The first gas infusion port 1111 is located near the proximal end of the first balloon body 21, and the second gas infusion port 1112 is located near the distal end of the first balloon body 21. The liquid infusion port 121 may also include a first liquid infusion port 1211 and a second liquid infusion port 1212. The first liquid infusion port 1211 is located near the proximal end of the second balloon body 22, and the second liquid infusion port 1212 is located near the distal end of the second balloon body 22.

[0046] The dual-infusion port layout design allows for a more thorough emptying operation of the balloon 20 before use. For example, when using the injection-emptying method, the balloon 20 can be placed vertically or upside down, allowing the air inside the balloon 20 to concentrate at the proximal or distal end and be fully expelled through the corresponding infusion port. This facilitates the complete emptying and contraction of the first balloon body 21 and the second balloon body 22, ensuring that the balloon 20 can be smoothly inserted into the body via interventional methods, while also avoiding the impact of residual air on measurement accuracy.

[0047] In other embodiments not shown, it is also possible to select only the gas injection port 111 to adopt the above-described dual injection port layout, or only the liquid injection port 121 to adopt the above-described injection port layout, as long as the design and usage requirements are met.

[0048] In one embodiment, please refer to Figure 2The first balloon 21 has a first conical transition section 211 at both its proximal and distal ends. When the first balloon 21 is inflated, a first conical transition region 212 with gradually changing radial dimensions is formed within the first conical transition section 211. The gas infusion port 111 is arranged corresponding to the tip of the first conical transition section 211 to communicate with the first conical transition region 212, which is beneficial for the complete emptying of the first balloon 21. The second balloon 22 has a second conical transition section 221 at both its proximal and distal ends. When the second balloon 22 is inflated, a second conical transition region 222 with gradually changing radial dimensions is formed within the second conical transition section 221. The liquid infusion port 121 is arranged corresponding to the tip of the second conical transition section 221 to communicate with the second conical transition region 222, which is beneficial for the complete emptying of the second balloon 22. The structure of the conical transition zone optimizes the venting channel, making it easier for air inside the balloon 20 to converge towards the corresponding infusion port, further improving the venting effect. At the same time, the smooth transition design of the conical transition section also helps to reduce stress concentration when the balloon 20 is inflated, which is beneficial to extending the service life of the balloon 20 and reducing the risk of balloon rupture.

[0049] In other embodiments not shown, the first balloon body 21 may be provided with a first conical transition section 211 only at the proximal or distal end, and the second balloon body 22 may be provided with a second conical transition section 221 only at the proximal or distal end, as long as the design and usage requirements are met.

[0050] In one embodiment, please refer to Figure 1 and Figure 2 In the circumference of catheter 10, gas infusion port 111 and liquid infusion port 121 are arranged at intervals, which helps to avoid mutual interference between different infusion ports, ensures that the injection process of gas and liquid contrast agents does not affect each other, and at the same time makes the stress on the wall of catheter 10 more uniform, optimizes the structural strength of catheter 10, avoids the problem of weak wall caused by multiple infusion ports being concentrated, and improves the compression and bending resistance of catheter 10 in interventional operations.

[0051] In one embodiment, please refer to Figure 1 and Figure 2 The gas infusion port 111 and the liquid infusion port 121 are located on opposite sides of the catheter 10 in the circumferential direction to maximize the spacing between the gas infusion port 111 and the liquid infusion port 121 in the circumferential direction of the catheter 10, thereby further enhancing the stability of the catheter 10 structure. At the same time, it allows the gas and liquid contrast agents to be more evenly distributed in the first balloon body 21 and the second balloon body 22 during injection, avoiding irregular shape of the balloon 20 caused by local medium accumulation, which is beneficial to ensuring the morphological stability and measurement accuracy of the measurement segment 23.

[0052] In one embodiment, please refer to Figure 1 and Figure 2The catheter 10 also has a guidewire insertion channel 13 inside for inserting the guidewire. The guidewire insertion channel 13 is independent of the first perfusion channel 11 and the second perfusion channel 12, which are arranged around the periphery of the guidewire insertion channel 13. For example, the guidewire insertion channel 13 is arranged axially inside the catheter 10, and the first and second perfusion channels 11 and 12 are both arranged in a direction parallel to the axial direction of the catheter 10 and can be arranged on opposite sides of the guidewire insertion channel 13. The arrangement of the guidewire insertion channel 13 provides independent space for guidewire insertion, ensuring that the guidewire can smoothly guide the balloon catheter to the atrial septal defect. At the same time, arranging the two perfusion channels around the guidewire insertion channel 13 makes the internal structure of the catheter 10 more reasonable and compact, fully utilizing the internal space of the catheter 10, avoiding interference between the channels, and helping to ensure the delivery efficiency of gaseous and liquid contrast agents and the smoothness of guidewire operation.

[0053] In one embodiment, please refer to Figure 1 and Figure 4 The balloon catheter also includes an interface component 30, which is fixedly connected to the proximal end of the catheter 10. The interface component 30 includes a first infusion interface 31, a second infusion interface 32, and a guidewire insertion interface 33. The first infusion interface 31 communicates with the first infusion channel 11 and is specifically used to connect a gas input device to introduce gas into the first infusion channel 11. The second infusion interface 32 communicates with the second infusion channel 12 and is specifically used to connect a liquid contrast agent input device to introduce liquid contrast agent into the second infusion channel 12. The guidewire insertion interface 33 communicates with the guidewire insertion channel 13 and is specifically used for guidewire insertion. The guidewire insertion interface 33 is arranged along the axial direction of the catheter 10, which helps reduce bending during guidewire insertion and facilitates guidewire insertion. The interface component 30 allows medical personnel to easily control the injection and drainage of gas and liquid contrast agents, while also facilitating guidewire insertion and manipulation, thus improving the convenience and controllability of the surgical procedure.

[0054] It should be noted that the above embodiments, which describe the balloon catheter in conjunction with atrial septal defect detection, are only intended to clearly illustrate the inventive concept of the balloon catheter in this application and do not constitute a limitation on the balloon catheter. In other words, the application scenarios of the balloon catheter in this application are not limited to atrial septal defect detection, but can also be applied to the detection of other in vivo defects or interventional closure treatments, such as the detection of defects like patent ductus arteriosus, ventricular septal defect, and patent foramen ovale; the measurement of pulmonary artery diameter before pulmonary valve implantation; the measurement of vessel diameter at the implantation site before inferior vena cava filter implantation; and other scenarios requiring measurements at the treatment site during the diagnosis and treatment of peripheral vessels.

[0055] The above examples illustrate this application only to aid understanding and are not intended to limit its scope. Those skilled in the art to which this application pertains can make various simple deductions, modifications, or substitutions based on the ideas presented.

Claims

1. A balloon catheter, characterized in that, include: catheter; And a balloon disposed in the catheter, the balloon comprising a collapsible and inflatable first balloon body and a second balloon body, the first balloon body and the second balloon body being isolated from each other and at least partially overlapping along the axial direction of the catheter to form a measurement segment for traversing and accommodating tissue defects; The catheter defines a separate first perfusion channel and a second perfusion channel; The first infusion channel is connected to the inner cavity of the first balloon body and is used to infuse gas into the first balloon body; The second perfusion channel is connected to the inner cavity of the second balloon body and is used to perfuse liquid contrast agent into the second balloon body.

2. The balloon catheter as described in claim 1, characterized in that, The first balloon and the second balloon are arranged in an inner and outer nested structure, with the second balloon sleeved on the outside of the first balloon.

3. The balloon catheter as described in claim 2, characterized in that, The first balloon is located in the middle of the inner cavity of the second balloon along the axial direction of the catheter, and the walls of the first balloon and the second balloon are spaced apart.

4. The balloon catheter as described in claim 2, characterized in that, The first infusion channel and the second infusion channel are disposed inside the catheter; The first infusion channel further includes at least one gas infusion hole disposed on the wall of the catheter for connecting the inner cavity of the first balloon and the first infusion channel; The second infusion channel further includes at least one liquid infusion hole disposed on the wall of the catheter for connecting the inner cavity of the second balloon and the second infusion channel.

5. The balloon catheter as described in claim 4, characterized in that, The gas infusion port includes a first gas infusion port and a second gas infusion port. The first gas infusion port is located near the proximal end of the first balloon body, and the second gas infusion port is located near the distal end of the first balloon body. And / or, the liquid infusion port includes a first liquid infusion port and a second liquid infusion port, wherein the first liquid infusion port is disposed near the proximal end of the second balloon body, and the second liquid infusion port is disposed near the distal end of the second balloon body.

6. The balloon catheter as described in claim 4, characterized in that, The proximal and / or distal end of the first balloon includes a first conical transition section. When the first balloon is inflated, a first conical transition region with radially varying dimensions is formed within the first conical transition section. The gas infusion port is arranged corresponding to the tip of the first conical transition section to communicate with the first conical transition region; and / or, The proximal and / or distal ends of the second balloon body include a second conical transition section. When the second balloon body is inflated, a second conical transition zone with radially varying dimensions is formed within the second conical transition section. The liquid infusion port is arranged corresponding to the tip of the second conical transition section to communicate with the second conical transition zone.

7. The balloon catheter according to any one of claims 4 to 6, characterized in that, The gas injection holes and the liquid injection holes are arranged at intervals along the circumference of the conduit.

8. The balloon catheter as described in claim 7, characterized in that, The gas injection port and the liquid injection port are located on opposite sides of the circumferential direction of the conduit.

9. The balloon catheter according to any one of claims 4 to 6, characterized in that, The catheter is also provided with a guide wire insertion channel inside, and the first irrigation channel and the second irrigation channel are arranged around the guide wire insertion channel.

10. The balloon catheter as described in claim 9, characterized in that, The balloon catheter further includes an interface component connected to the catheter, comprising: The first injection port is connected to the first injection channel and is used to connect to the gas input device for gas input. The second infusion port is connected to the second infusion channel and is used to connect to the liquid contrast agent input device for liquid input. And a guidewire insertion interface, which is arranged along the axial direction of the catheter and communicates with the guidewire insertion channel for guidewire insertion.

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