Self-expanding catheter with guided guidewire and method of expansion

Abstract

The present application belongs to the technical field of cavity intervention treatment medical instrument, and particularly relates to a self-expanding catheter with a guide guide wire and an expanding method. The self-expanding catheter comprises a proximal operation area, a pipe body transmission area and a distal functional head area which are connected in sequence. The proximal operation area is integrated with four independent functional interfaces, a one-way valve and an indicating balloon. The pipe body transmission area is a multi-cavity composite hose containing four physically isolated flow channels. The distal functional head area is configured with a coaxial double-layer drug release expanding balloon, a fixed indicating balloon and an X-ray developing marker ring. The matching drug delivery method can realize the whole process operation of positioning, expanding, fixing, drug delivery and drainage in a single intubation. The present application can effectively shorten the operation time, reduce the risk of infection and mucosal injury, greatly improve the uniformity of lesion drug delivery and the accuracy of treatment, and provide a reliable instrument for patients to dilate stenosis.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology for intracavitary interventional therapy, specifically relating to a self-dilution catheter with a guide wire and a dilation method. Background Technology

[0002] In clinical practice, interventional treatment for various benign or malignant luminal stenosis typically involves multiple steps, including guidewire guidance, dilation of the stenotic site, and local drug administration to the lesion. However, existing mainstream dilation catheters generally suffer from low functional integration. Single-function catheters require repeated insertion and removal during the procedure, which not only significantly prolongs the operation time but also greatly increases the probability of complications such as mucosal injury, bleeding, and cross-infection. Some integrated dilation catheters also have obvious structural design defects: either the dilation channel and the drug administration channel are not completely physically isolated, which can easily lead to drug reflux and unstable dilation pressure, or there is no visual pressure feedback structure, and the operator relies entirely on experience to control the degree of dilation, which can easily lead to insufficient dilation resulting in poor efficacy or excessive dilation leading to perforation of the catheter wall. At the same time, most catheters lack a reliable intraoperative axial fixation structure, which can easily cause displacement during dilation or drug administration, resulting in deviation of the dilation position and deviation of the drug spray from the lesion. Furthermore, the distal drug administration structure of existing catheters is mostly single-hole drug delivery, resulting in poor uniformity of drug distribution and difficulty in achieving full coverage of the lesion site, further limiting the clinical treatment effect. All of the above-mentioned dilation catheters require repeated visits to the hospital to be operated by experienced physicians. Patients cannot perform these procedures at home, which is extremely inconvenient.

[0003] Chinese Patent CN118846345B discloses a balloon dilation catheter, which includes a double-layer balloon assembly and a drill assembly. The double-layer balloon assembly includes an inner tube, an outer tube sleeved outside the inner tube, an outer balloon located at the distal end of the outer tube, and an inner balloon located at the distal end of the inner tube. The inner balloon is located within the outer balloon, and the distal ends of both the inner and outer balloons are provided with end caps that can be opened and closed. The drill assembly includes a movable catheter and a drill structure located at the distal end of the movable catheter. The movable catheter is inserted into the inner tube. The balloon dilation catheter has a first working state and a second working state. In the first working state, the drill structure is located within the inner balloon, and the end cap is closed. In the second working state, at least a portion of the drill structure is located outside the distal end of the inner balloon, and the end cap is open. By operating the movable catheter, the balloon dilation catheter can be switched between the first and second working states, and the drill structure can extend from the distal end of the inner balloon to perform deep drilling into the thrombus tissue. The aforementioned device has two independent flow channels: drill bit reception and balloon dilation. There is no physically isolated drug delivery channel and fixation balloon channel. Therefore, the four core treatment functions—stenosis dilation, lesion drug delivery, catheter fixation, and postoperative drainage—cannot operate independently in parallel. To complete a full interventional treatment procedure for stenosis, repeated insertion and removal of catheters with different functions is required. Therefore, it is urgent for those skilled in the art to solve these technical problems. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, this design utilizes four independent channels: a physically isolated central main lumen, an dilation balloon channel, a drug delivery interlayer channel, and a fixation balloon channel. This allows for simultaneous stenosis dilation, lesion drug delivery, catheter fixation, and postoperative drainage with a single insertion, eliminating the need for repeated catheter changes during surgery. This significantly shortens the procedure time and reduces the risk of iatrogenic injury. The initial visit allows for accurate measurement of the catheter's position and distance from the incisors, providing guidance on proper use and eliminating the need for repeated hospital visits.

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

[0006] A self-dilation catheter with a guidewire includes a proximal operating area, a tube body delivery area, and a distal functional head area connected in sequence. The proximal operating area includes four independent ports, a one-way valve, an indicator balloon, and a guidewire inlet. The tube body delivery area is a multi-lumen composite tube with physically isolated internal flow channels and graduated markings on the outer wall of the tube body. The entire tube body delivery area is made of flexible tubing.

[0007] The distal functional head area includes a capsule structure, a metal marker ring, and a guidewire exit;

[0008] The capsule structure includes a coaxially nested double-layered dilatation balloon and a fixed indicator balloon. The double-layered dilatation balloon includes an inner balloon and an outer balloon. The inner balloon is connected to the dilatation balloon channel inside the tube body, and the outer balloon is connected to the drug delivery interlayer channel inside the tube body. The outer balloon has drug release micropores evenly distributed on its wall. The indicator balloon is connected to the fixed balloon channel inside the tube body.

[0009] By adopting the above technical solution, and using an integrated design of the proximal operating area, the tube body transmission area, and the distal functional head area, and through a combination structure of four physical isolation channels, a double-layer dilation balloon, and a fixation indicator balloon, the entire process of dilation, drug delivery, fixation, and drainage can be covered in a single insertion. This eliminates the need for repeated catheter replacements during the procedure, directly shortens the operation time, and reduces the probability of iatrogenic complications such as mucosal damage, bleeding, and cross-infection. It fundamentally solves the problems of cumbersome operation and limited functionality of existing single-function dilation catheters.

[0010] Furthermore, the four independent interfaces of the proximal operating area are specifically as follows:

[0011] The drainage port is located on the extension line of the main shaft of the hub sleeve, and its internal flow channel is directly connected to the central main cavity of the tube body; the expansion bladder inflation port and the fixed bladder inflation port are respectively located on the first side wing of the hub sleeve, and a duckbill one-way valve is connected in series in the pipeline of both ports.

[0012] The drug delivery channel is located on the second side wing of the manifold, connecting to the annular drug delivery interlayer cavity inside the tube body;

[0013] The one-way valve is installed on the pipeline between the corresponding interface and the indicator balloon.

[0014] By adopting the above technical solution, the partitioned layout of the four independent interfaces on the hub sleeve and the series position of the duckbill one-way valve not only conform to the ergonomic habits of clinical interventional operation, allowing operators to quickly distinguish different functional interfaces and avoid misoperation, but also the duckbill one-way valve can effectively prevent the backflow of gas and medicine in the pipeline without the need for additional locking structure, simplifying the structural complexity of the proximal operation area and reducing production and processing costs.

[0015] Furthermore, the tube body transmission area is equipped with four physically isolated flow channels:

[0016] The central main cavity, which is the largest diameter flow channel, extends along the entire length of the tube and is used to accommodate the guidewire and realize the drainage function; the dilatation bladder flow channel is a small diameter flow channel, which is connected to the inner bladder at its distal end;

[0017] The fixed balloon flow channel is a small-diameter flow channel, with its distal end connected to the indicator balloon;

[0018] The drug delivery interlayer channel is connected at its distal end to the internal interlayer of the outer capsule, and is used to deliver the drug solution to the interlayer space between the outer capsule and the inner capsule.

[0019] The scale markings on the outer wall of the tube are formed by laser etching, with a scale spacing of 1mm. The starting zero point of the scale is aligned with the preset positioning reference surface of the remote functional head area.

[0020] By adopting the above technical solution, the functional division of the four flow channels and the scale parameters of the tube body, as well as the physically isolated flow channel design, completely avoid the risk of cross-contamination between the expansion gas path, drug delivery path, and drainage path. The precise scale with a 1mm spacing allows the operator to intuitively judge the insertion depth of the catheter without having to repeatedly confirm the position through angiography, which greatly improves the efficiency of operation. At the same time, the laser-etched scale will not have problems such as ink peeling or unclear imaging, making it more reliable.

[0021] Furthermore, the components of the remote functional head area are stacked sequentially from the inside out:

[0022] The inner bladder has its proximal neck sealed and fixed to the outlet end of the dilatation bladder channel by heat sealing or adhesive bonding, and its distal neck sealed and fixed to the tip of the mandrel, communicating only with the dilatation bladder channel to form a closed chamber.

[0023] The outer capsule is coaxially sleeved outside the inner capsule, forming an annular interlayer space between them. The proximal and distal necks of the outer capsule are sealed and fixed on the spindle. The outer capsule is connected to the drug delivery interlayer channel through the openings in the sidewall. Drug release micropores are evenly distributed on the capsule wall.

[0024] The length of the adhesive fixing section between the inner capsule and the outer capsule is 1mm~2mm;

[0025] The indicator balloon is positioned at the distal outlet of the fixed balloon channel, on the proximal side of the double-layered dilatation balloon.

[0026] By adopting the above technical solution, the stacking order of the distal functional areas from the inside out and the bonding length of the inner and outer balloons, the coaxial stacking structure is a mature processing technology for interventional balloons, which can significantly improve the production yield. The bonding length of 1mm~2mm not only ensures the sealing reliability of the inner and outer balloons and prevents leakage of liquid and air, but also avoids the balloon end being too hard and scratching the mucosa due to excessively long bonding sections. At the same time, the fixed indicator balloon is set on the proximal side of the double-layer expansion balloon, which will not interfere with the expansion range. The structural logic is rigorous and reasonable.

[0027] Furthermore, the metal marking ring is embedded in the mandrel groove at the corresponding position of the double-layer dilatation balloon, or fixed between the inner and outer balloons by heat shrink tubing. The metal marking ring is an X-ray radiopaque structure and serves as a positioning reference for the dilatation center.

[0028] The guide wire outlet is located at the farthest end of the tube body, and the tube opening has a smooth conical head structure with a guide wire channel formed in the center. The fitting clearance between the guide wire channel and the guide wire satisfies the following: when the guide wire diameter is 0.89 mm, the diameter of the guide wire channel is 0.95 mm, which is suitable for guide wire insertion. After the guide wire is inserted, its J-shaped bend can extend out from the guide wire outlet.

[0029] By adopting the above technical solution, the fixing method of the metal marker ring and the matching gap of the guidewire channel allow the operator to accurately locate the dilation center during the operation, avoiding the dilation position from deviating from the lesion. The 0.06mm guidewire matching gap ensures that the guidewire is inserted smoothly without jamming, and avoids leakage caused by excessive gap. It is compatible with the clinically common 0.89mm diameter guidewire, without the need for additional customized consumables, and has stronger clinical adaptability.

[0030] The present invention further discloses a self-administered dilation catheter method for supplying medication via a dilation catheter with a guide wire, comprising the following steps:

[0031] S1. Push the catheter along the guidewire to the target stenosis location inside the body;

[0032] S2. Pressurized gas is injected into the inner bladder through the inflation port of the expansion bladder, causing the inner bladder to expand radially and push the outer bladder to expand outward synchronously to compress the tube wall of the narrow part.

[0033] S3. Inflate the fixation indicator balloon through the fixation balloon inflation port to inflate the fixation indicator balloon and fix the axial position of the catheter.

[0034] S4. Inject the drug solution into the interlayer space between the outer and inner capsules through the drug delivery channel, so that the drug solution is evenly sprayed to the target area through the drug release micropores of the outer capsule wall.

[0035] S5. Perform drainage operations through the drainage interface, or perform guidewire adjustment operations.

[0036] By adopting the above technical solution, the steps of positioning, dilation, fixation, drug administration, and finally drainage and guidewire adjustment do not interfere with each other. Operators can quickly get started without changing their existing operating habits. At the same time, the entire process does not require changing the catheter, which greatly reduces the operation threshold and allows doctors in primary hospitals to complete the operation smoothly.

[0037] Further, step S2 specifically involves: injecting pressurized gas through the inflation port of the expansion bladder, the gas opening the duckbill-type one-way valve in the corresponding pipeline and entering the inner bladder, while a small amount of gas enters the parallel expansion-side indicator bladder, causing the expansion-side indicator bladder to expand synchronously to provide visual feedback on the expansion pressure.

[0038] During the radial expansion of the inner capsule, which pushes the outer capsule to expand outward and compress the narrow wall, the interlayer space between the inner and outer capsules remains relatively still and does not affect subsequent drug delivery.

[0039] When pressure relief is needed, external force presses the valve core of the one-way valve to open the bypass hole, allowing gas to be discharged in the reverse direction.

[0040] By adopting the above technical solution, the surgeon can intuitively judge the expansion pressure by synchronously expanding the balloon on the expansion side, without the need for additional pressure detection equipment, thus reducing treatment costs. At the same time, the inner and outer balloon layers remain relatively still during expansion, which will not affect the uniformity of subsequent drug administration. The pressure relief operation can be achieved simply by pressing the one-way valve core. In case of emergency, pressure relief and tube removal can be completed quickly, which greatly improves the safety of operation.

[0041] Further, step S3 specifically involves: injecting pressurized gas through the inflation port of the fixation bladder, the gas opening the duckbill-type one-way valve in the corresponding pipeline, and reaching the fixed indicator balloon at the distal end through the flow channel of the fixation bladder;

[0042] After inflation, the fixed indicator balloon conforms to the surrounding tissue, restricting the axial displacement of the catheter. Moreover, the fixed indicator balloon is located on the proximal side of the double-layer dilatation balloon, so it does not interfere with the dilatation function of the double-layer dilatation balloon.

[0043] During fixation, the synchronous inflation of the fixation-side indicator balloon provides visual feedback on the fixation status, facilitating the operator's monitoring of the fixation effect.

[0044] By adopting the above technical solution, the distal fixation indicator balloon can firmly adhere to the surrounding tissue after inflation, completely avoiding the problem of axial displacement of the catheter during dilation and drug delivery. The operator does not need to hold the fixation catheter throughout the process, reducing the operator's operational burden. At the same time, the visual feedback of the fixation side indicator balloon allows the operator to intuitively confirm the fixation status without the need for angiography to verify the fixation effect, further shortening the operation time.

[0045] Further, step S4 specifically involves injecting a therapeutic solution through the drug delivery channel, and the solution being transported through the drug delivery interlayer channel to the interlayer space between the inner and outer capsules.

[0046] As the pressure of the drug solution in the interlayer space increases, the drug solution is evenly sprayed onto the target area through the drug release micropores on the outer capsule wall.

[0047] During drug administration, the drug administration interlayer flow channel and the expansion bladder flow channel are physically isolated from each other, which does not affect the stability of the expansion pressure of the inner bladder;

[0048] The uniformity of drug spraying is controlled by the distribution density and pore size parameters of the drug release micropores on the outer capsule wall.

[0049] By adopting the above technical solution, the drug delivery channel and the expansion channel are physically isolated, and the drug delivery process will not affect the stability of the expansion pressure of the inner capsule, avoiding the problem of expansion position deviation caused by pressure fluctuation. At the same time, the drug solution is evenly sprayed through the micropores of the outer capsule, which can achieve full coverage of the lesion mucosa. The drug dosage and spray range can be precisely controlled by the micropore parameters, which greatly improves the effect of drug delivery and treatment.

[0050] Further, step S5 specifically involves: when a guidewire operation is required, inserting a guidewire through the drainage interface, the guidewire reaching the target position via the central main lumen, a silicone sealing gasket fitted at the guidewire inlet to prevent liquid leakage and lock the axial position of the guidewire, and the J-shaped bend of the guidewire extending out after insertion to guide the catheter through narrow or twisted anatomical sites.

[0051] When drainage is required, an external negative pressure device is connected through the drainage interface, and the drainage material is discharged from the body through the central main cavity.

[0052] By adopting the above technical solution, the silicone sealing gasket at the guide wire inlet can effectively prevent liquid leakage and lock the guide wire position to avoid guide wire displacement. The drainage and guide wire operation share the central main cavity, eliminating the need for additional flow channels and simplifying the processing difficulty of the tube structure. At the same time, the drainage operation is completed directly through the central main cavity without the need for additional drainage pipeline, greatly improving the ease of operation.

[0053] Compared with the prior art, the beneficial effects of this invention are as follows:

[0054] 1. This invention establishes four independent channels within a multi-lumen composite tube: a central main lumen, an expansion balloon channel, a drug delivery interlayer channel, and a fixed balloon channel. Combined with a coaxially nested double-layer expansion balloon and a distal fixed indicator balloon structure, this invention enables a single insertion to simultaneously complete the entire treatment process, including lumen stenosis dilation, targeted drug delivery to the lesion, catheter axial fixation, and postoperative drainage / guidewire adjustment. This eliminates the need for repeated insertions and removals of different functional catheters during the procedure, shortening the operation time and significantly reducing the risk of iatrogenic complications such as mucosal abrasion, bleeding, and cross-infection.

[0055] 2. This invention features a multi-dimensional visualization design with laser-etched scales on the catheter body, X-ray-visible metal marking rings, and a proximal bidirectional indicating balloon. Operators can intuitively judge the catheter insertion depth, accurately locate the dilation center, and monitor the dilation pressure and fixation status in real time without repeated angiography confirmation. This not only improves the accuracy of operation and avoids deviation of dilation and drug delivery from the lesion, but also reduces the reliance on operational experience. Physicians in primary hospitals can also quickly learn to complete the treatment.

[0056] 3. This invention employs a double-layered balloon design with an inner balloon that expands and an outer balloon with drug-release micropores. Combined with a completely physical isolation structure between the expansion channel and the drug delivery channel, the drug delivery process does not interfere with the stability of the inner balloon's expansion pressure. The drug solution can be sprayed evenly and completely over the lesion mucosa through the micropores of the outer balloon. The dosage and spray range can be precisely controlled through the micropore parameters, which greatly improves the local drug delivery and treatment effect.

[0057] 4. This invention measures the position and distance from the incisors during the first medical visit, instructing the patient on correct use. Afterward, there is no need for repeated visits to the hospital; the patient can operate it at home safely and conveniently. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0059] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0060] Figure 2 This is a schematic diagram of the internal structure of the present invention;

[0061] Figure 3 This is a schematic diagram of a physical embodiment of the present invention featuring an independent interface;

[0062] Figure 4 This is a schematic diagram of the bent structure of the device of the present invention;

[0063] Figure 5 This is a schematic diagram of the unfolded structure of the device of the present invention.

[0064] Figure 6 This is a flowchart of the method of the present invention.

[0065] Among them, 1-proximal operating area; 11-independent interface; 111-drainage interface; 112-expansion balloon inflation port; 113-fixation balloon inflation port; 114-drug delivery channel port; 12-one-way valve; 13-indicator balloon; 14-guidewire inlet; 2-tube body transport area; 21-balloon structure; 22-double-layer expansion balloon; 221-outer balloon; 2211-drug release micropore; 222-inner balloon; 23-central main lumen; 24-fixation balloon flow channel; 25-drug delivery interlayer flow channel; 26-expansion balloon flow channel; 27-gradient marking; 28-mandrel; 3-distal functional head area; 31-guidewire; 32-J-shaped elbow; 33-axial fixation balloon. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0067] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As can be seen, this invention discloses a self-expanding catheter with a guidewire. All components of this self-expanding catheter with a guidewire are arranged coaxially along the axis. The whole is divided into three core modules: the proximal operating area 1, the catheter body transmission area 2, and the distal functional head area 3, which are sealed and connected in sequence. The assembly and positional relationship of each component fully follows the high reliability and low assembly complexity process logic of interventional devices.

[0068] First, the manifold is used as the assembly base for the proximal operating area 1. Four independent interfaces 11 are integrated in different positions of the manifold according to functional partitions. The drainage interface 111 is fixed on the main axis extension line of the manifold, serving as the core central flow channel access end. The expansion bladder inflation port 112 and the fixation bladder inflation port 113 are fixed side by side on the first wing of the manifold. The drug delivery channel port 114 is fixed on the second wing of the manifold. The partitioned layout design not only conforms to operating habits but also facilitates the corresponding insertion of the flow channels during the assembly process. Each independent interface has a duckbill-type one-way valve 12 connected in series in its internal tubing. The one-way valve 12 is connected in parallel with the corresponding interface tubing to the indicator balloon 13. The guide wire inlet 14 is integrated at the proximal end of the drainage interface 111, and a silicone sealing gasket is embedded inside to achieve the sealing and locking function when the guide wire 31 is inserted.

[0069] The proximal end of the multi-cavity composite tube in the tube body transmission area 2 is sealed and connected to the output end of the hub sleeve. The four physically isolated flow channels inside the tube body are respectively inserted and connected to the inner tubing of their corresponding interfaces. The largest diameter central main cavity 23 is directly connected to the inner flow channel of the drainage interface 111; the small-diameter expansion bladder flow channel 26 is connected to the inner tubing of the expansion bladder inflation port 112; the small-diameter fixed bladder flow channel 24 is connected to the inner tubing of the fixed bladder inflation port 113; and the drug delivery interlayer flow channel 25 is connected to the inner tubing of the drug delivery channel 114. The four flow channels... The tube extends the entire length without cross-linking, completely avoiding the risk of cross-contamination between different functional media. Laser-etched graduations on the outer wall of the tube are evenly distributed axially, with the zero point of the graduations aligned with the preset positioning reference surface of the distal functional head area 3, facilitating position calibration during assembly and intraoperative depth assessment. The distal functional head area 3 uses a mandrel as the supporting framework for all distal components. The proximal end of the mandrel is sealed and fixed to the distal axis of the tube's transmission area 2. The inner capsule 222, as the inner layer of the double-layered dilatation balloon 22, is coaxially fitted onto the outside of the mandrel. The proximal neck is sealed and fixed to the distal outlet end of the expansion balloon channel 26, and the distal neck is sealed and fixed to the tip of the mandrel, so that the inner bladder 222 forms a closed chamber that communicates only with the expansion balloon channel 26. An X-ray radiopaque metal marker ring is embedded in the groove of the mandrel corresponding to the position of the inner bladder 222, serving as a positioning reference for the expansion center. The outer bladder 221, as the outer layer of the double-layer expansion balloon 22, is coaxially sleeved on the outermost side of the mandrel. Both the proximal and distal necks of the outer bladder 221 are sealed and fixed to the mandrel, forming a ring with the inner bladder 222. The outer capsule 221 has a shaped interlayer space that is connected to the drug delivery interlayer channel 25 through an opening in the side wall of the outer capsule 221. The outer capsule 221 has a uniformly dense distribution of drug release micropores 2211 on its wall. The inner capsule 222 and the outer capsule 221 together form the core functional part of the capsule structure 21, which is used to realize the synergistic function of expansion and drug delivery. The indicator balloon 13 is assembled as an axial fixation functional component at the distal outlet of the fixation balloon channel 24. It is located on the proximal side of the double-layer expansion balloon 22 and has no structural interference with the double-layer expansion balloon 22, so it will not affect the realization of the expansion function.

[0070] The very end of the entire distal functional head area 3 is a guidewire outlet with a smooth conical head structure, which is connected to the central main lumen 23 of the tube body. The guidewire 31 can be inserted from the proximal guidewire inlet 14, pass through the central main lumen 23, and then extend from the distal guidewire outlet to realize the guiding function of the catheter.

[0071] In one embodiment, four independent interfaces 11 serve as input / output ports for proximal operations. During operation, the surgeon connects to the corresponding external devices according to the operation stage. The drainage interface 111 connects to the negative pressure drainage device or guidewire insertion tool as needed. The balloon inflation port 112 connects to the inflation device to provide power for balloon expansion. The fixation balloon inflation port 113 connects to the inflation device to achieve axial fixation of the catheter. The drug delivery channel port 114 connects to the syringe to achieve drug delivery. Each interface works independently without interference, adapting to the functional requirements of different operation stages.

[0072] A duckbill-type one-way valve 12 is connected in series in the corresponding pipelines of the expansion bladder inflation port 112 and the fixed bladder inflation port 113. When inflating, the pressurized medium opens the valve core of the one-way valve 12 and flows in the forward direction. After inflation is completed, the valve core automatically rebounds and locks the pipeline to prevent gas backflow from causing a drop in bladder pressure. When pressure needs to be released, external force can press the valve core to open the bypass pipeline and realize the reverse discharge of the medium. Stable pressure maintenance and rapid pressure release can be achieved without the need for additional locking structure.

[0073] The indicator balloon 13 is divided into two types: proximal pressure feedback balloon and distal fixation balloon. The proximal indicator balloon 13 is connected in parallel between the corresponding inflation port and the distal balloon tubing. During inflation, a small amount of medium enters the proximal indicator balloon 13 to make it expand synchronously. The operator can intuitively judge the pressure status of the distal balloon by observing the degree of expansion of the proximal indicator balloon 13. After inflation, the distal indicator balloon 13 fits against the surrounding cavity tissue, restricts the axial displacement of the catheter, and avoids the catheter deviating from the lesion position during the operation.

[0074] The guidewire inlet 14 is integrated into the proximal end of the drainage interface 111 and is fitted with a silicone sealing gasket. When the guidewire 31 is inserted, the sealing gasket is squeezed and deformed to fit the outer wall of the guidewire, preventing liquid leakage in the cavity. After the guidewire 31 is inserted, the elastic tension of the sealing gasket can lock the axial position of the guidewire 31. No additional fixing structure is needed to prevent the guidewire from shifting, and it does not affect the guidewire extraction and adjustment operation.

[0075] The central main lumen 23, as the largest through-flow channel inside the tube, extends along the entire axis of the catheter. During the guidewire insertion stage, it provides guidance for the guidewire 31 to pass through and push the catheter. During the drainage stage, it serves as a drainage channel for the fluid and secretions accumulated in the lumen to be discharged from the body. There is no need to set up an additional independent drainage channel, realizing the multi-functional reuse of a single flow channel.

[0076] The fixation balloon flow channel 24 is an independent small-diameter flow channel inside the tube body. Its proximal end is connected to the fixation balloon inflation port 113, and its distal end is connected to the distal indicator balloon 13. It is only used to transmit the inflation medium of the fixation balloon and is physically isolated from other flow channels throughout the entire process. During inflation, it will not interfere with the expansion pressure or drug dosage, ensuring the independent controllability of the fixation function.

[0077] The drug delivery interlayer channel 25 is an independent annular channel inside the tube body. Its proximal end is connected to the drug delivery channel 114, and its distal end is connected to the interlayer space between the outer bladder 221 and the inner bladder 222. It is only used to transmit the therapeutic drug solution and is physically isolated from other channels throughout the entire process. It will not affect the pressure stability of the dilation balloon during drug delivery, nor will it cause cross-contamination with the drainage medium or inflation medium.

[0078] The dilatation balloon flow channel 26 is an independent small-diameter flow channel inside the tube body. Its proximal end is connected to the dilatation balloon inflation port 112, and its distal end is connected to the closed chamber of the inner balloon 222. It is only used to transmit the inflation medium of the dilatation balloon and is physically isolated from other flow channels throughout the process. During the adjustment of the dilatation pressure, it will not interfere with the normal operation of the drug delivery and fixation functions, and ensures the precise control of the dilatation pressure.

[0079] The inner bladder 222 serves as the inner load-bearing structure of the double-layered expansion balloon 22. When inflated, it expands uniformly in the radial direction, pushing the outer bladder 221 to expand synchronously and compress the tube wall of the narrow part. When depressurized, it retracts synchronously. During the entire operation, its closed chamber is only connected to the expansion balloon flow channel 26 and will not come into contact with the drug solution in the interlayer space, thus avoiding cross-contamination between the expansion medium and the drug solution.

[0080] The outer capsule 221, as the outer functional structure of the double-layered dilatation balloon 22, expands synchronously with the inner capsule 222 to fit the mucosa of the lesion site. During the drug administration phase, after the drug pressure in the internal interlayer space increases, the drug solution is evenly seeped out and sprayed onto the surface of the lesion mucosa through the drug release micropores 2211 on the capsule wall, realizing targeted drug administration. Throughout the process, the outer capsule 221 only serves as a carrier and release carrier for the drug solution and does not bear the function of expansion force, thus avoiding the influence of expansion stress on the uniformity of drug release.

[0081] The drug-releasing micropores 2211 are evenly distributed on the wall of the outer capsule 221. When the drug is administered, the outer capsule 221 expands synchronously to the preset pore size. The drug liquid in the interlayer space seeps out through the drug-releasing micropores 2211 under pressure. Its distribution density and pore size parameters can be adapted to the drug administration rate requirements of different drug liquids, so as to achieve precise control of drug dosage and spray range.

[0082] The metal marker ring is embedded on the core shaft at the corresponding position of the double-layer dilatation balloon 22. It is an X-ray visible structure. During the operation, the position of the metal marker ring can be clearly observed through the imaging equipment. The surgeon can use it as a positioning reference to quickly determine whether the double-layer dilatation balloon 22 is aligned with the center of the lesion, and avoid the dilation and drug delivery position deviating from the lesion area.

[0083] The guidewire 31 is inserted into the central lumen 23. During the insertion phase, its J-shaped bend extends from the distal guidewire outlet, guiding the catheter smoothly through narrow and tortuous anatomical sites to reach the target position. After the catheter is positioned, the guidewire 31 can be retained or withdrawn as needed without affecting the normal conduct of subsequent dilation, drug administration, and drainage operations.

[0084] The present invention further discloses a method for dilating a dilator catheter, which utilizes a dilator catheter with a guide wire to deliver medication, comprising the following steps:

[0085] S1. Push the catheter along guidewire 31 to the target stenotic position inside the body;

[0086] S2. Pressurized gas is injected into the inner bladder 222 through the inflation port 112 of the expansion bladder, causing the inner bladder 222 to expand radially and push the outer bladder 221 to expand outward synchronously to compress the tube wall of the narrow part.

[0087] S3. Gas is introduced into the fixed indicator balloon 13 through the fixed balloon inflation port 113 to inflate the fixed indicator balloon 13 and fix the axial position of the catheter.

[0088] S4. Inject the drug solution into the interlayer space between the outer capsule 221 and the inner capsule 222 through the drug delivery channel 114, so that the drug solution is evenly sprayed to the target area through the drug release micropores 2211 on the wall of the outer capsule 221.

[0089] S5. Perform drainage operation through drainage interface 111, or perform guide wire 31 adjustment operation.

[0090] Step S2 is as follows: pressurized gas is injected through the inflation port 112 of the expansion bladder. The gas opens the duckbill-type one-way valve 12 in the corresponding pipeline and enters the inner bladder 222. At the same time, a small amount of gas enters the parallel expansion side indicator balloon 13, so that the expansion side indicator balloon 13 expands synchronously to provide visual feedback on the expansion pressure.

[0091] During the radial expansion of the inner capsule 222, which pushes the outer capsule 221 to expand outward and compress the narrow wall, the interlayer space between the inner capsule 222 and the outer capsule 221 remains relatively static and does not affect subsequent drug delivery operations.

[0092] When pressure relief is required, external force presses the valve core of the one-way valve 12 to open the bypass hole, thereby allowing the gas to be discharged in the reverse direction.

[0093] Step S3 specifically involves injecting pressurized gas through the inflation port 113 of the fixed bladder. The gas opens the duckbill-type one-way valve 12 in the corresponding pipeline and reaches the fixed indicator balloon 13 at the distal end through the flow channel 24 of the fixed bladder.

[0094] After inflation, the fixed indicator balloon 13 fits against the surrounding tissue, restricting the axial displacement of the catheter. Moreover, the fixed indicator balloon 13 is located on the proximal side of the double-layer dilatation balloon 22, without interfering with the dilatation function of the double-layer dilatation balloon 22.

[0095] During fixation, the synchronous inflation of the fixation-side indicator balloon 13 provides visual feedback on the fixation status, facilitating the operator's monitoring of the fixation effect.

[0096] Step S4 specifically involves injecting a therapeutic solution through the drug delivery channel 114, and delivering the solution to the interlayer space between the inner capsule 222 and the outer capsule 221 via the drug delivery interlayer channel 25.

[0097] As the pressure of the drug solution in the interlayer space increases, the drug solution is evenly sprayed to the target area through the drug release micropores 2211 on the wall of the outer capsule 221.

[0098] During drug administration, the drug administration interlayer channel 25 and the dilation bladder channel 26 are physically isolated from each other, which does not affect the stability of the dilation pressure of the inner bladder 222.

[0099] The uniformity of drug spraying is controlled by the distribution density and pore size parameters of the drug release micropores 2211 on the wall of the outer capsule 221.

[0100] Step S5 is as follows: When the guidewire 31 needs to be operated, the guidewire 31 is inserted through the drainage interface 111. The guidewire 31 reaches the target position through the central main lumen 23. The silicone sealing gasket installed at the guidewire inlet 14 is used to prevent liquid leakage and lock the axial position of the guidewire 31. After the guidewire 31 is inserted, its J-shaped bend extends out to guide the catheter through narrow or twisted anatomical sites.

[0101] When drainage is required, an external negative pressure device is connected through the drainage interface 111, and the drainage material is discharged from the body through the central main cavity 23.

[0102] First, the operator injects the therapeutic solution through the drug delivery channel 114. After entering, the solution is transported distally along the physically isolated drug delivery interlayer channel 25. Throughout this process, it remains completely independent of the central main cavity 23, the dilation sac channel 26, and the fixed sac channel 24, thus avoiding interference from dilation pressure fluctuations, drainage media, and any potential drug loss due to cross-flow. After being delivered distally via the drug delivery interlayer channel 25, the solution enters the annular interlayer space between the outer sac 221 and the inner sac 222. This interlayer space is formed by the sealing and fixation of the anterior and posterior necks of the outer sac 221. During the expansion process, as the inner capsule 222 radially expands and pushes the outer capsule 221 to expand synchronously, the interlayer space remains relatively static, and the uniform distribution of the drug solution is not affected by the expansion deformation. As the drug solution is continuously injected, the pressure in the interlayer space gradually increases. The pressure drives the drug solution to permeate evenly into the densely distributed drug-release micropores 2211 on the capsule wall of the outer capsule 221. The pore size and distribution density of the drug-release micropores 2211 are preset according to the treatment needs to ensure that the drug solution seeps out at a stable rate after the pressure reaches the threshold. The seeped drug solution is evenly sprayed onto the interlayer space. The outer wall of the outer capsule 221 adheres to the surface of the lesion mucosa, achieving full coverage of the lesion area for drug delivery. At this time, the inner capsule 222 maintains a stable expansion pressure, compressing the surrounding narrow tissue to fix the catheter position and prevent catheter displacement during drug delivery, which could cause the drug solution to spray into normal tissue areas. Throughout the drug delivery process, the duckbill-type one-way valve 12 always locks the tubing of the expansion capsule inflation port 112 and the fixation capsule inflation port 113, ensuring the pressure of the inner capsule 222 and the distal fixation indicator balloon 13 remains stable, preventing pressure drop or catheter displacement due to drug delivery operations. At the same time, the proximal indicator balloon 13 synchronously displays the current expansion and fixation status, allowing the operator to visually confirm the stability of the drug delivery environment. After drug delivery, there is no need to depressurize before proceeding directly to the subsequent drainage or guidewire adjustment stage. If the drug delivery dosage needs to be adjusted, the drug solution can be replenished or withdrawn simply through the drug delivery channel port 114. The entire drug delivery process does not require changing the catheter or adjusting the catheter position; it can be completed solely by operating the drug delivery channel port 114. This ensures the accuracy and uniformity of drug delivery, greatly simplifies the operation process, and reduces the difficulty of operation.

[0103] In one embodiment, refer to Figure 3 , Figure 4 and Figure 5As can be seen, this single-interface guide tube uses a reinforced hose body as its core support base. The main connector 14 is sealed and fixed to the proximal end of the hose body through a heat-sealing process, serving as the proximal access port of the main passage and also as the guide wire inlet. Two independent branch pipes extend from the side wall of the main connector 14. The two branch pipes are axially arranged along the outer wall of the hose body and are fitted and fixed to the tube body. The shorter branch pipe has a sealed and fixed inflation port 11 at its end, with a one-way valve structure connected in series inside to control the inflation and deflation passages. The longer branch pipe has a side cavity port 114 at its end, used for drug delivery or access to other functional media. The internal flow channels of both branch pipes are connected to the hose body. The central main access is physically isolated throughout. The distal end of the tubing body is shaped into a beveled tip 12, which serves as the guidewire outlet and the distal opening of the main access. An expansion balloon 22 is coaxially fitted onto the outer wall of the tubing body near the tip 12. The anterior and posterior necks of the expansion balloon 22 are heat-sealed and fixed to the outer wall of the tubing body. Its internal closed chamber is connected to the branch tubing belonging to the inflation port 11. The branch tubing belonging to the side port 114 extends along the inside of the tubing body to the side opening of the tip 12. The coaxiality of all components is controlled within the tolerance range of medical devices, and the sealing positions have been verified by leakage testing to ensure that each functional access operates independently without interference.

[0104] In use, the guidewire is first inserted into the central lumen of the tube through the proximal main interface 14. The tube is then pushed to the target airway position along the pre-inserted guidewire. During the push, the flexible tube with reinforcing ribs adapts to the physiological curvature of the airway, avoiding damage to the mucosa. After positioning, pressurized gas is injected through the inflation interface 11. The gas is transmitted along the independent side lumen inside the tube to the distal balloon 22, causing it to inflate and conform to the airway wall to achieve axial locking of the tube and airway sealing. After fixation, mechanical ventilation can be achieved by connecting the breathing circuit through the main interface 14. Alternatively, therapeutic drugs, topical anesthetics, or irrigation solutions can be injected through the drug delivery interface 114. The drug is transmitted along the corresponding side lumen to the opening at the distal tip 12 and released into the target area. If the position of the tube needs to be adjusted, simply release the gas in the balloon 22 through the inflation interface 11 for free adjustment. Re-inflate to fix it. The entire operation does not require changing instruments. The single main interface layout is adapted to the operational needs of rapid intubation in emergency situations, effectively shortening the operation time.

[0105] In one embodiment, the distance from the incisors to the location of the narrowed cavity in the patient is determined by imaging measurements. A self-dilution catheter with a guidewire 31 is then pushed along the pre-inserted guidewire 31 to the target location. Positioning is calibrated using the X-ray imaging metal marker ring 29 in the distal functional head area 3. Simultaneously, the complete procedure is demonstrated to the patient: Holding the proximal operating area 1, the guidewire 31 is first inserted through the guidewire inlet 14 into the central main lumen 23 of the tube body transmission area 2, allowing the J-shaped bend 32 at the tip of the guidewire 31 to extend distally. Referring to the laser-etched graduation marks 27 on the outer wall of the tube body transmission area 2, the catheter is pushed to the memorized target depth. Subsequently, pressurized fluid is injected into the inner balloon 222 through the inflation port 112 on the first flank of the proximal operating area 1. The fluid opens the one-way valve 12 of the corresponding tubing and enters the inner balloon 222, pushing the outer balloon 221 to expand synchronously and compress the narrowed tube wall. The parallel pressure indicator balloon 13 expands synchronously to provide visual pressure feedback. After reaching the preset expansion pressure, fluid is injected into the axially fixed balloon 33 through the inflation port 113 on the same side wing, causing it to expand and fit against the inner wall of the cavity to fix the axial position of the catheter. Then, the therapeutic drug is injected into the interlayer space between the outer balloon 221 and the inner balloon 222 through the drug delivery channel 114 on the second side wing. After the drug reaches the interlayer through the drug delivery interlayer channel 25, it is sprayed onto the lesion area through the drug release micropores 2211 evenly distributed on the wall of the outer balloon 221. After the drug delivery is completed, a negative pressure device can be connected through the drainage interface 111 at the proximal main axis position as needed to drain the fluid in the cavity through the central main cavity 23. After the operation is completed, the valve cores of the one-way valves 12 corresponding to the two inflation ports are pressed in sequence to release the pressure, and the catheter is pulled out to complete the entire process. After the patient is familiar with the operation points and remembers the target depth parameters, there is no need to go to the hospital repeatedly. The patient can complete the self-expansion treatment at home according to the same procedure. The entire process is physically isolated from each channel and the operation is guided by visual feedback, ensuring both safety and convenience.

[0106] Working principle: First, guidewire 31 is inserted into the central main lumen 23 and pushed to the lesion area. During the process of the catheter entering the body along guidewire 31, the operator can visually judge the insertion depth through the laser-etched scale on the catheter body. The relative position of the double-layer dilatation balloon 22 and the lesion is precisely calibrated by the metal marker ring visualized under X-ray. After positioning, pressurized gas is injected into the inner balloon 222 through the balloon inflation port 112. The gas opens the duckbill-type one-way valve 12 in the corresponding tubing and enters the inner balloon 222, causing it to expand radially. Simultaneously, it drives the outer balloon 221 to expand to open the narrow cavity. The parallel proximal indicator balloon 13 expands synchronously to provide the surgeon with intuitive pressure feedback, allowing the surgeon to determine the degree of dilation without additional pressure detection equipment. Subsequently, gas is inflated into the distal fixed indicator balloon 13 through the fixed balloon inflation port 113, causing it to conform to the surrounding tissue and lock the catheter's axial position, preventing catheter displacement during subsequent procedures. Then, the therapeutic solution is injected through the drug delivery channel 114. The solution is delivered through an independent drug delivery interlayer channel 25 to the annular interlayer space between the outer balloon 221 and the inner balloon 222. As the pressure within the interlayer increases, the solution flows through the outer balloon 221... The drug-releasing micropores 2211, evenly distributed on the wall, allow for precise spraying onto the surface of the diseased mucosa, achieving targeted drug delivery. Finally, depending on treatment needs, a negative pressure device can be connected via drainage interface 111 to drain accumulated fluid through the central main lumen 23, or the guidewire 31 can be adjusted to complete subsequent procedures. The entire treatment process requires only one intubation. This addresses the core pain points of existing dilation catheters, which only have two flow channels and limited function, requiring repeated insertion and removal of different functional catheters during surgery, leading to long operation times, mucosal abrasion, and high risks of cross-infection. The four physically isolated flow channels provide a comprehensive solution. The procedure completely avoids interference between dilation, drug delivery, drainage, and fixation functions. The distal fixation indicator balloon 13 solves the problems of easy axial displacement and the need for the operator to hold the balloon for fixation throughout the traditional procedure. The structure of the double-layer balloon with drug-release micropores 2211 solves the defects of uneven drug delivery distribution and poor accuracy after traditional dilation. The four independent interfaces 11 with proximal partition layout and duckbill one-way valve 12 also solve the operational difficulties of easy interface confusion and easy backflow of media in traditional procedures. While reducing the difficulty of the operation, it greatly improves the safety and effect of treatment.

[0107] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-dilation catheter with a guidewire, comprising a proximal operating area (1), a catheter body delivery area (2), and a distal functional head area (3) connected in sequence, characterized in that: The proximal operating area (1) includes at least one independent interface (11), a one-way valve (12), a pressure indicating balloon (13), and a guidewire inlet (14). The tube body transmission area (2) is a multi-cavity composite tube body with physical isolation between the internal flow channels. The outer wall of the tube body is marked with scale marks. The tube body transmission area (2) is made of flexible tubing. The tube body transmission area (2) has a flow channel that communicates with the distal capsule structure (21) inside. The distal functional head area (3) includes a guide wire (31), and a J-shaped bend (32) is provided at the distal end of the guide wire (31). The capsule structure (21) includes a coaxially nested double-layer expansion balloon (22) and an axially fixed balloon (33). The double-layer expansion balloon (22) includes an inner capsule (222) and an outer capsule (221). The inner capsule (222) is connected to the expansion balloon channel (26) inside the tube body. The outer capsule (221) is connected to the drug delivery interlayer channel (25) inside the tube body, and drug release micropores (2211) are evenly distributed on the capsule wall of the outer capsule (221). The axially fixed balloon (33) is connected to the fixed balloon channel (24) inside the tube body. The pressure indicating balloon (13) is connected in parallel with the expansion balloon channel (26) and the fixed balloon channel (24) to provide pressure visual feedback.

2. The self-dilation catheter with guide wire according to claim 1, characterized in that, The proximal operating area (1) includes a hub sleeve and four independent interfaces (11): The drainage interface (111) is located on the main shaft extension line of the hub sleeve, and its internal flow channel is directly connected to the central main cavity (23) of the tube body. The inflation port (112) of the expansion balloon and the inflation port (113) of the fixation balloon are respectively located on the first side wing of the hub sleeve. A duckbill-type check valve (12) is connected in series in the pipeline of both ports. The check valve (12) is located in the pipeline between the corresponding port and the pressure indicating balloon (13). The drug delivery channel (114) is located on the second side wing of the manifold and connects to the annular drug delivery interlayer cavity inside the tube body, i.e., the drug delivery interlayer flow channel (25).

3. The self-dilation catheter with guide wire according to claim 1, characterized in that, The physically isolated flow channels inside the tube body transmission area (2) specifically include: The central main cavity (23) is the largest flow channel in terms of pipe diameter, extending along the entire length of the pipe body, and is used to accommodate the guide wire (31) and realize the drainage function; The expansion sac flow channel (26) is a small-diameter flow channel, and its distal end is connected to the inner sac (222). The fixed balloon channel (24) is a small-diameter channel, and its distal end is connected to the axially fixed balloon (33). The drug delivery interlayer channel (25) is connected at its distal end to the internal interlayer of the outer capsule (221) for delivering the drug solution to the interlayer space between the outer capsule (221) and the inner capsule (222); The scale markings (27) on the outer wall of the tube are formed by laser etching.

4. The self-dilation catheter with guide wire according to claim 1, characterized in that, The components of the remote functional head area (3) are stacked sequentially from the inside out: The proximal neck of the inner capsule (222) is sealed and fixed to the outlet end of the dilatation capsule flow channel (26), and the distal neck is sealed and fixed to the tip of the mandrel, communicating only with the dilatation capsule flow channel (26) to form a closed chamber; The outer capsule (221) is coaxially sleeved on the outside of the inner capsule (222), forming an annular interlayer space between them. The proximal and distal necks of the outer capsule (221) are sealed and fixed on the spindle (28). The outer capsule (221) is connected to the drug delivery interlayer channel (25) through the opening in the side wall. Drug release micropores (2211) are evenly distributed on the capsule wall. The axially fixed balloon (33) is positioned at the distal outlet of the fixed balloon channel (24), located on the proximal side of the double-layered dilatation balloon (22).

5. The self-dilation catheter with guide wire according to claim 1, characterized in that: The double-layer dilatation balloon (22) and the tube body transmission area (2) are integrally formed, and a metal marking ring (29) is provided at the splice of the double-layer dilatation balloon (22) and the tube body transmission area (2). The guide wire (31) is inserted into the central main cavity (23), and its distal end extends beyond the farthest end of the tube body.

6. A method for dilating a self-administered dilation catheter, characterized in that, The procedure is achieved using the dilation catheter with a guide wire as described in any one of claims 1 to 5, comprising the following steps: S1. Push the catheter along the guide wire (31) to the target stenosis location in the body; S2. Pressurized fluid is injected into the inner bladder (222) through the inflation port (112) of the expansion bladder, causing the inner bladder (222) to expand radially and push the outer bladder (221) to expand outward synchronously to compress the tube wall of the narrow part; S3. Fluid is injected into the axial fixation balloon (33) through the fixation balloon inflation port (113) to inflate the axial fixation balloon (33) and fix the axial position of the catheter. S4. Inject the drug solution into the interlayer space between the outer capsule (221) and the inner capsule (222) through the drug delivery channel (114), so that the drug solution is evenly sprayed to the target area through the drug release micropores (2211) on the wall of the outer capsule (221); S5. Perform drainage operation through the drainage interface (111) or adjust the guide wire (31).

7. The expansion method according to claim 6, characterized in that, The specific steps of step S2 are as follows: pressurized fluid is injected through the inflation port (112) of the expansion bladder. The fluid opens the duckbill-type one-way valve (12) in the corresponding pipeline and enters the inner bladder (222). At the same time, a small amount of fluid enters the parallel pressure indicating balloon (13), so that the pressure indicating balloon (13) expands synchronously to provide visual feedback on the expansion pressure. During the process of the radial expansion of the inner capsule (222) pushing the outer capsule (221) to expand outward and compress the narrow wall, the interlayer space between the inner capsule (222) and the outer capsule (221) remains relatively stationary; When pressure relief is required, external force presses the valve core of the check valve (12) to open the bypass hole and realize the reverse discharge of fluid.

8. The expansion method according to claim 6, characterized in that, Step S3 specifically involves: Pressurized fluid is injected through the inflator (113) of the fixation bladder. The fluid opens the duckbill-type check valve (12) in the corresponding pipeline and reaches the axial fixation bladder (33) at the distal end through the fixation bladder channel (24). After the axial fixation balloon (33) is inflated, it fits the target area and restricts the axial displacement of the catheter. The axial fixation balloon (33) is located on the proximal side of the double-layer dilatation balloon (22) and does not interfere with the dilatation function of the double-layer dilatation balloon (22). During the fixation process, the pressure indicator balloon (13) connected in parallel with the fixation balloon channel (24) expands synchronously to provide visual feedback on the fixation status, which is convenient for monitoring the fixation effect.

9. The expansion method according to claim 6, characterized in that, Step S4 specifically involves: The therapeutic solution is injected through the drug delivery channel (114) and delivered to the interlayer space between the inner capsule (222) and the outer capsule (221) via the drug delivery interlayer channel (25); As the pressure of the drug solution in the interlayer space increases, the drug solution is evenly sprayed to the target area through the drug release micropores (2211) on the wall of the outer capsule (221); During drug administration, the drug administration interlayer channel (25) and the expansion bladder channel (26) are physically isolated from each other, which does not affect the expansion pressure stability of the inner bladder (222); The uniformity of drug spraying is controlled by the distribution density and pore size parameters of the drug release micropores (2211) on the wall of the outer capsule (221).

10. The expansion method according to claim 6, characterized in that, Step S5 specifically involves: When a guide wire (31) operation is required, the guide wire (31) is inserted through the guide wire inlet (14). The guide wire (31) reaches the target position through the central main cavity (23). The silicone sealing gasket installed at the guide wire inlet (14) is used to prevent liquid leakage and lock the axial position of the guide wire (31). After the guide wire (31) is inserted, its J-shaped bend (32) guides the conduit to the target area. When drainage is required, an external negative pressure device is connected through the drainage interface (111), and the drainage material is discharged from the body through the central main cavity (23).

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