Anti-winding intestinal obstruction catheter system and catheter indwelling method

Abstract

The invention discloses an anti-winding intestinal obstruction catheter system and method. The anti-winding intestinal obstruction catheter system comprises a handle, a catheter body and a rigidity adjusting device. The catheter body is a flexible body, the near end of the catheter body is connected with the handle, and the far end of the catheter body is provided with a balloon and a charging pipeline communicated with the balloon; the rigidity adjusting device is connected with the catheter body and used for adjusting the bending rigidity of the catheter body after the catheter body is placed into the duodenum. The anti-winding intestinal obstruction catheter system is adopted in the catheter indwelling method of the anti-winding intestinal obstruction catheter, and the anti-winding intestinal obstruction catheter system and method can effectively prevent the catheter from being wound, improve the catheter indwelling success rate and ensure the operation safety at the same time.

Description

Technical Field

[0001] This invention specifically relates to an anti-entanglement intestinal obstruction catheter system and a catheter placement method. Background Technology

[0002] Intestinal obstruction is a common surgical emergency. Obstruction of intestinal contents can cause symptoms such as abdominal pain, bloating, and vomiting, and in severe cases, can lead to life-threatening complications such as intestinal perforation and septic shock. Nasoenteric catheterization is an important non-surgical treatment for this condition. This method involves inserting a long catheter through the nasal cavity into the intestine. After the catheter's tip is inflated with water, the intestinal peristalsis propels the catheter towards the site of obstruction, thereby decompressing the proximal intestinal segment and relieving obstruction symptoms.

[0003] The traditional intestinal obstruction catheters currently widely used in clinical practice have the following main drawbacks: 1. The catheter body is a uniform flexible body. When it travels in the long and tortuous intestine, it is very easy to coil or knot at the dilated or curved parts of the intestinal lumen (i.e., "entanglement"), which will lead to catheter placement failure and failure to reach the target position. 2. The advancement of the catheter relies entirely on intestinal peristalsis, which is slow and uncontrollable, often taking several hours or even days, delaying treatment and increasing patient suffering; 3. Although some solutions have attempted to add guidewires to the catheter to increase overall rigidity and prevent tangling, this method makes the catheter too rigid throughout, which greatly increases the risk of puncturing or scratching the fragile intestinal wall during the advancement process, resulting in poor safety. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the technical problem to be solved by this invention is to provide an anti-entanglement intestinal obstruction catheter system and placement method that can effectively prevent entanglement, improve the success rate of placement, and ensure operational safety.

[0005] To achieve the above objectives, the present invention provides a technical solution as follows: an anti-tangle intestinal obstruction catheter system, comprising: handle; The catheter body is a flexible body, the proximal end of the catheter body is connected to the handle, the distal end of the catheter body is provided with a balloon, and an inflation tubing connected to the balloon; A stiffness adjustment device, connected to the catheter body, is used to adjust the bending stiffness of the catheter body after it is inserted into the duodenum.

[0006] Furthermore, the catheter body includes a sealing block, an outer tube, and a central guidewire. The central guidewire is a spirally wound spring wire with its distal end extending outward and its proximal end connected to the sealing block. The outer tube is sleeved over the central guidewire, with its distal end sealing its proximal end and sealingly connected to the sealing block. The sealing block is connected to the handle, and the balloon is mounted on the outer tube.

[0007] Furthermore, the stiffness adjustment device includes a stiffness adjustment tube and an injection pump. The stiffness adjustment tube is located inside the outer tube and sleeved outside the central guide wire. The distal end of the stiffness adjustment tube is closed and the proximal end is sealed to the sealing block. The injection pump is connected to the stiffness adjustment tube through a water pipe and is used to inject or extract fluid into the stiffness adjustment tube.

[0008] Furthermore, it also includes a rotating mechanism, wherein the top of the sealing block is rotatably connected to the handle via a central shaft, and the rotating drive mechanism is connected to the sealing block for driving the sealing block to rotate around the central shaft.

[0009] Furthermore, the rotary drive mechanism includes a rotary handle, a driving gear, a transmission gear set, and a driven gear. The rotary handle is rotatably mounted on the handle. The driving gear is sleeved on the rotary handle. The driven gear is sleeved and fixed outside the sealing block. The transmission gear set meshes between the driving gear and the driven gear. The transmission ratio of the transmission gear set is greater than one.

[0010] Furthermore, it also includes a pressurizing mechanism connected to the stiffness adjusting tube, which is used to synchronously increase the pressure inside the stiffness adjusting tube when the sealing block is driven to rotate clockwise, thereby increasing the bending stiffness of the conduit body.

[0011] Furthermore, the pressurization mechanism includes a push plate, a threaded rod, and a drive guide rod. The push plate is disposed inside the stiffness adjustment tube and can slide along the axial direction of the stiffness adjustment tube. One end of the drive guide rod is fixed to the sealing block, and the other end can slide through the push plate. The threaded rod is coaxially disposed with the central shaft. The push plate is sleeved on the threaded rod and threadedly connected to the threaded rod. The proximal end of the central guide wire is fixed to the push plate.

[0012] A method for inserting an anti-tangle intestinal obstruction catheter, employing the aforementioned anti-tangle intestinal obstruction catheter system, the method comprising: Initial insertion procedure: Keep the catheter body in its initial flexible state, insert it through the nasal cavity and rely on intestinal peristalsis to advance it into the duodenum; Active intervention steps: After the catheter body reaches the duodenum, the drive mechanism on the handle set outside the body is operated to actively increase the bending stiffness of the catheter body and make it rotate, so as to assist the catheter in passing through the bends of the intestine and prevent it from getting tangled, until the tip of the catheter reaches the target obstruction position.

[0013] Furthermore, in the active intervention step, fluid is injected into the stiffness adjustment tube inside the catheter body via an injection pump to increase its internal pressure, thereby increasing the bending stiffness of the catheter.

[0014] Furthermore, in the active intervention step, the catheter body is driven to rotate by rotating the handle, and this rotation is automatically converted into the compression of the fluid in the stiffness adjustment tube by a pressurizing mechanism, thereby increasing the bending stiffness of the catheter simultaneously while rotating and advancing.

[0015] The above-mentioned anti-tangle intestinal obstruction catheter system and placement method have at least the following advantages: 1. Effectively prevents catheter entanglement and improves placement success rate: By connecting a stiffness adjustment device to the catheter body, doctors can actively adjust the bending stiffness of the catheter body after it is inserted into the duodenum, according to the actual situation. When the catheter needs to pass through long, loose, or tortuous intestinal segments, the increased stiffness keeps the catheter straight, effectively resisting bending and coiling caused by axial pressure. This fundamentally solves the technical problem of traditional catheters being prone to "entanglement and coiling," significantly improving the success rate of catheter placement to the obstruction site on the first attempt.

[0016] 2. Achieving a balance between safety and effectiveness: Unlike traditional methods that rely on adding a guidewire to increase overall rigidity, this method offers adjustable rigidity. When navigating relatively safe or less rigid sections such as the esophagus and stomach, the catheter maintains its inherent flexibility, minimizing the risk of puncture or abrasion of the intestinal wall. Rigidity is only temporarily increased when navigating potentially tangled or dangerous intestinal segments. This "combination of rigidity and flexibility" ensures effective advancement while significantly enhancing operational safety.

[0017] 3. Improved treatment efficiency: Unlike traditional catheters, doctors no longer need to passively rely on slow bowel movements or repeatedly change catheters or guidewires of different stiffness. The flexibility of the catheter can be controlled in real time by operating an external stiffness adjustment device, giving doctors greater autonomy, helping to guide the catheter to the target location more quickly, shortening treatment time, and reducing patient discomfort. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0019] Figure 1 This is a schematic diagram of an anti-entanglement intestinal obstruction catheter system provided in an embodiment of the present invention; Figure 2 for Figure 1 The diagram shows a partial cross-sectional view of the anti-tangle intestinal obstruction catheter system. Figure 3 for Figure 2 A schematic diagram at point A in the middle; Figure 4 for Figure 2 Schematic diagram at point BB; Figure 5 for Figure 1 The diagram shows the downward movement of the push plate in the anti-tangle intestinal obstruction catheter system. Figure label: 100. Handle; 200. Catheter body; 210. Sealing block; 220. Outer tube; 230. Central guide wire; 300. Stiffness adjustment device; 310. Stiffness adjustment tube; 320. Injection pump; 330. Water pipe; 400. Rotary drive mechanism; 410. Central shaft; 420. Rotating handle; 430. Driving gear; 440. Transmission gear set; 450. Driven gear; 500. Pressure boosting mechanism; 510. Push plate; 520. Threaded rod; 530. Drive guide rod. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention; therefore, the invention is not limited to the specific embodiments disclosed below.

[0021] Please see Figures 1 to 5 The present invention provides an anti-entanglement intestinal obstruction catheter system, including a handle 100, a catheter body 200 and a stiffness adjustment device 300.

[0022] Specifically, the handle 100 is an operating handle used during catheter insertion. The catheter body 200 is a flexible body; its proximal end is connected to the handle 100, and its distal end is equipped with a balloon and an inflation tubing connected to the balloon. When the catheter is inserted to the predetermined position, the entire catheter body 200 can be fixed in the body by injecting gas or liquid into the balloon.

[0023] The stiffness adjustment device 300 is connected to the catheter body 200 and is used to adjust the bending stiffness of the catheter body 200 after it is inserted into the duodenum.

[0024] Principle and Operation Explanation: During initial insertion, the catheter remains flexible, mimicking the natural progression of a traditional catheter by intestinal peristalsis. Once it reaches the duodenum, if imaging indicates the catheter may enter a long, easily coiled segment of the intestine (such as the jejunum), the stiffness adjustment device 300 can be activated. This device significantly enhances the overall bending resistance by altering the physical state of the catheter's internal structure.

[0025] This design addresses the issues of "easy entanglement and coiling" and "inadequacy of existing anti-entanglement solutions" in the prior art. Adjustable stiffness means that the catheter remains flexible in most safe sections, reducing the risk of injury; stiffness is only temporarily increased when it needs to traverse complex intestinal segments, effectively resisting bending stress and preventing looping and knotting, thus achieving a balance between safety and effectiveness.

[0026] In this embodiment, the catheter body 200 includes a sealing block 210, an outer tube 220, and a central guidewire 230. The central guidewire 230 is composed of a spirally wound metal spring wire, with its distal end extending freely and its proximal end fixedly connected to a sealing block 210. The outer tube 220 is sleeved outside the central guidewire 230, with its distal end closed and its proximal end sealingly connected to the sealing block 210, thereby forming a sealed annular cavity between the two. The sealing block 210 also serves as an interface for connection with the handle 100. The balloon is positioned on the outer side of the distal end of the outer tube 220.

[0027] The central guide wire 230, as the core load-bearing component, possesses a helical spring wire structure that allows it to exhibit both bending resistance and torque transmission in its natural state. In practical implementation, the helical spring wire material can be stainless steel or nickel-titanium alloy. The outer tube 220, as the outermost layer in contact with human tissue, provides biocompatibility and forms a seal. The outer tube 220 can be made of an elastic polymer material.

[0028] In this embodiment, the stiffness adjustment device 300 includes a stiffness adjustment tube 310 and an infusion pump 320. The stiffness adjustment tube 310 is located in the annular cavity between the outer tube 220 and the central guide wire 230, and is itself a flexible thin tube that is closed at its distal end and sealed to the sealing block 210 at its proximal end. The infusion pump 320 is connected to the proximal cavity of the stiffness adjustment tube 310 through a water pipe 330 passing through the sealing block 210. By operating the infusion pump 320, fluid (such as physiological saline) can be injected or withdrawn into the stiffness adjustment tube 310. Using physiological saline as the pressure transmission medium is the safest choice. In the extremely rare event of a leak, physiological saline will not cause any chemical damage or irritation to human tissue, meeting the highest safety standards for medical devices.

[0029] When fluid is injected into the stiffness adjustment tube 310 via the injection pump 320, the internal hydraulic pressure increases, causing the flexible tube wall to deform radially and axially due to the increased internal pressure. This deformation exerts an axial compressive force on the internal central guide wire 230, forcing the gaps between the coils of the spirally wound spring wire to decrease or even tightly adhere, thereby greatly increasing the bending stiffness of the central guide wire 230. Since the central guide wire 230 is the skeleton of the catheter, its increased stiffness directly leads to an increase in the bending stiffness of the entire catheter body 200. Conversely, withdrawing the fluid causes the catheter to return to its flexible state.

[0030] This method solves the problem of "inability to dynamically adapt to different intestinal segments." Doctors can manually control the rigidity of the catheter according to real-time needs, making the operation intuitive and reliable.

[0031] In a preferred embodiment, the system further includes a rotating mechanism. The top of the sealing block 210 is rotatably connected to the handle 100 via a central shaft 410. The rotating drive mechanism 400 is connected to the sealing block 210 and its function is to drive the sealing block 210 and cause the entire catheter body 200 (including the outer tube 220, the central guidewire 230, etc.) fixedly connected to it to rotate together around the central shaft 410.

[0032] This rotating mechanism provides a secondary driving force for active propulsion. When intestinal peristalsis is insufficient to advance the catheter or when there is a risk of catheter entanglement, the doctor can activate this mechanism to slowly rotate the entire catheter. This rotational propulsion method mimics the principle of a "drill," effectively helping the catheter tip to bypass intestinal folds and bends, fundamentally solving the problems of "completely passive propulsion" and "easy entanglement," significantly improving the success rate and efficiency of catheter placement.

[0033] Specifically, the rotary drive mechanism 400 includes a rotating handle 420, a driving gear 430, a transmission gear set 440, and a driven gear 450. The rotating handle 420 is rotatably mounted on the housing of the handle 100. The driving gear 430 is fixedly mounted on the shaft of the rotating handle 420. The driven gear 450 is fixedly mounted on the outer periphery of the sealing block 210. The transmission gear set 440 meshes between the driving gear 430 and the driven gear 450, and its transmission ratio is greater than one.

[0034] In use, the doctor manually rotates the rotating handle 420, transmitting motion and torque to the driven gear 450 via the driving gear 430 and the transmission gear set 440. Since the driven gear 450 is fixed to the sealing block 210, it drives the sealing block 210 and the entire catheter to rotate. The design with a transmission ratio greater than one means that a doctor only needs to make a large, easy rotation on the handle 100 to achieve a smaller, more precise rotation of the sealing block 210, avoiding irritation or damage to the intestines caused by sudden torque changes.

[0035] As a further preferred embodiment, the system also includes a pressurizing mechanism 500. The pressurizing mechanism 500 is connected to the stiffness regulating tube 310. When the rotating mechanism drives the conduit body 200 to rotate (advance) clockwise, the pressurizing mechanism 500 can automatically and synchronously increase the pressure in the stiffness regulating tube 310 instantaneously, thereby realizing an instantaneous automatic increase in the stiffness of the conduit.

[0036] This mechanism combines "rotational propulsion" with "increased stiffness." During active propulsion, the catheter automatically stiffens to provide better thrust transmission efficiency; in the non-propulsion state, the catheter remains flexible. This not only optimizes the operating procedure but also significantly improves the system's performance and safety. Furthermore, it eliminates the need for the physician to simultaneously operate the infusion pump 320 while rotating the handle 420, thus significantly improving ease of use.

[0037] Specifically, the pressurizing mechanism 500 includes a push plate 510, a threaded rod 520, and a drive guide rod 530. The push plate 510 is disposed within the sealed cavity of the stiffness adjustment tube 310 and can slide axially therein. One end of the drive guide rod 530 is fixed to the sealing block 210, and the other end passes through a hole in the push plate 510, providing guidance to prevent it from rotating with the threaded rod 520. The threaded rod 520 is coaxially arranged with the central shaft 410, and its proximal end is connected to the handle 100 housing via a bearing, allowing it to rotate freely but remain axially fixed. The push plate 510 has a threaded hole at its center that engages with the threaded rod 520. The proximal end of the central guide wire 230 is fixed to the push plate 510.

[0038] In use, when the sealing block 210 is rotated by the rotary drive mechanism 400, since the proximal end of the central guide wire 230 is fixed on the push plate 510, and the push plate 510 is restricted from rotating by the drive guide rod 530, the rotational motion of the sealing block 210 relative to the push plate 510 is transformed into a relative rotational motion. Because the push plate 510 and the threaded rod 520 are threadedly engaged, and the threaded rod 520 itself is axially fixed, the aforementioned relative rotational motion forces the push plate 510 to move forward (towards the distal end) along the axial direction of the drive guide rod 530 and the threaded rod 520. The movement of the push plate 510 compresses the central guide wire 230 in front of it, and simultaneously compresses the fluid in front of it, thus instantly increasing the hydraulic pressure within the stiffness adjustment tube 310, thereby achieving automatic stiffening of the conduit.

[0039] Furthermore, in practical implementation, to prevent the water pipe connected to the stiffness adjustment pipe from interfering with the operation, the water pipe 330 and the threaded rod 520 can be coaxially arranged, and the water pipe 330 can be inserted into the stiffness adjustment pipe 310 through the threaded rod 520. The water pipe 330 and the threaded rod 520 can be rotatably and sealedly connected, thus preventing the water pipe 330 from interfering with the operation.

[0040] The above-mentioned anti-tangle intestinal obstruction catheter system, through the stiffness adjustment device 300, the rotation mechanism and the pressurization mechanism 500, can effectively solve the problems of slow advancement, easy tangling and coiling and insufficient anti-tangle capability of the intestinal obstruction catheter system during the insertion process.

[0041] In addition, this application also discloses a method for inserting an anti-tangle intestinal obstruction catheter, which uses the aforementioned anti-tangle intestinal obstruction catheter system, and the method includes: Initial insertion procedure: Keep the catheter body (200) in its initial flexible state, insert it through the nasal cavity and advance it into the duodenum by intestinal peristalsis; Active intervention steps: After the catheter body (200) reaches the duodenum, the bending stiffness of the catheter body (200) is actively increased and it rotates by operating the drive mechanism on the handle (100) set outside the body, so as to assist the catheter in passing through the bend of the intestine and prevent it from getting tangled, until the tip of the catheter reaches the target obstruction position.

[0042] Specifically, the initial insertion procedure is performed: the medical staff holds the handle (100) to maintain the catheter body (200) in its initial, low bending stiffness state (i.e., the flexible state where the stiffness adjustment device (300) is not activated). The distal end of the catheter is slowly inserted through the patient's nasal cavity, and relying on the peristalsis of the intestines, the catheter tip passes through the esophagus and stomach in sequence, and finally enters the duodenum. During this stage, the catheter remains flexible to minimize stimulation and damage to the intestinal tissues.

[0043] Once X-ray imaging and other technical means confirm that the catheter tip has reached the duodenum, the active intervention procedure begins. Medical staff operate the drive mechanism on the externally mounted handle (100). This drive mechanism actively increases the bending stiffness of the catheter body (200), enabling it to resist bending and coiling in the subsequent long and winding jejunum and ileum; simultaneously, the drive mechanism causes the catheter body (200) to rotate around its axis. This active intervention mode of "rigid-flexible combination" and "rotational advancement" effectively helps the catheter traverse intestinal bends, prevents it from becoming entangled in dilated intestinal segments, and ultimately ensures that the water-filled balloon at the catheter tip reaches the target obstruction location, achieving effective decompression.

[0044] In the active intervention step, stiffness adjustment is specifically achieved by operating the infusion pump (320). The medical staff manually controls the infusion pump (320) to inject the sterile saline (as the preferred fluid) stored in it into the stiffness adjustment tube (310) inside the catheter body (200) through the water tube (330).

[0045] As fluid is injected, the internal pressure of the stiffness adjustment tube (310) increases, causing radial expansion of the tube body. This applies radial clamping force and / or axial compressive force to the central guidewire (230) embedded inside. This force reduces the gap between the turns of the spirally wound central guidewire (230), enhancing their mutual support and significantly improving the bending stiffness of the entire catheter body (200). This method enables external, real-time, and controllable adjustment of catheter stiffness, which is key to solving the catheter entanglement problem.

[0046] In addition, during the active intervention step, the medical staff rotates the rotating handle (420) on the handle (100) to drive the catheter to rotate forward. At this time, this rotation triggers the pressure boosting mechanism (500) to work automatically: the rotation of the rotating handle (420) is transmitted through the gear set, ultimately driving the sealing block (210) and the drive guide rod (530) fixed thereon to rotate relative to the push plate (510). Since the push plate (510) is engaged with the fixed threaded rod (520) by the thread and is restricted from rotating by the drive guide rod (530), this relative rotation forces the push plate (510) to move distally along the catheter axis. The movement of the push plate (510) squeezes the central guide wire (230) in front of it on the one hand, and squeezes the fluid in the front cavity of the stiffness adjustment tube (310) on the other hand, thereby instantaneously and automatically increasing the fluid pressure in the stiffness adjustment tube (310).

[0047] 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. An anti-kinking intestinal obstruction catheter system, characterized by, The device comprises: a handle; a catheter body, which is a flexible body, a proximal end of the catheter body being connected to the handle, a distal end of the catheter body being provided with a balloon, and a filling pipe line being in communication with the balloon; a rigidity adjusting device, which is connected to the catheter body, for adjusting the bending rigidity of the catheter body after the catheter body is placed into the duodenum.

2. The anti-wrap intestinal obstruction catheter system of claim 1, wherein: The catheter body comprises a sealing block, an outer tube and a center guide wire, the center guide wire being a helically wound spring wire, a distal end of the center guide wire extending outward, a proximal end of the center guide wire being connected to the sealing block, the outer tube being sleeved outside the center guide wire, and a distal end of the outer tube being sealedly connected to the sealing block, the sealing block being connected to the handle, and the balloon being arranged on the outer tube.

3. The anti-wrap intestinal obstruction catheter system of claim 2, wherein: The rigidity adjusting device comprises a rigidity adjusting tube and a syringe pump, the rigidity adjusting tube being located inside the outer tube and sleeved outside the center guide wire, a distal end of the rigidity adjusting tube being sealedly connected to the sealing block, and the syringe pump being in communication with the rigidity adjusting tube through a water pipe, for injecting or extracting fluid into or out of the rigidity adjusting tube.

4. The anti-wrap intestinal obstruction catheter system of claim 3, wherein: Further comprising a rotating mechanism, a top of the sealing block being rotatably connected to the handle through a center shaft, and a rotating driving mechanism being connected to the sealing block, for driving the sealing block to rotate around the center shaft.

5. The anti-wrap intestinal obstruction catheter system of claim 4, wherein: The rotating driving mechanism comprises a rotating handle, a driving gear, a transmission gear set and a driven gear, the rotating handle being rotatably arranged on the handle, the driving gear being sleeved on the rotating handle, the driven gear being fixedly sleeved outside the sealing block, the transmission gear set being engaged between the driving gear and the driven gear, and a transmission ratio of the transmission gear set being greater than one.

6. The anti-wrap intestinal obstruction catheter system of claim 4, wherein: Further comprising a pressure boosting mechanism, which is connected to the rigidity adjusting tube, for synchronously increasing the pressure in the rigidity adjusting tube when the sealing block is driven to rotate clockwise, so as to increase the bending rigidity of the catheter body.

7. The anti-wrap intestinal obstruction catheter system of claim 6, wherein: The pressure boosting mechanism comprises a push plate, a threaded rod and a driving guide rod, the push plate being arranged in the rigidity adjusting tube and being slidable along an axial direction of the rigidity adjusting tube, one end of the driving guide rod being fixed on the sealing block and the other end being slidably penetrating through the push plate, the threaded rod being coaxially arranged with the center shaft, the push plate being sleeved on the threaded rod and being threadedly connected with the threaded rod, and a proximal end of the center guide wire being fixed on the push plate.

8. A method of placing an anti-kinking intestinal obstruction catheter, characterized by, The method comprises: an initial placement step: keeping the catheter body in an initial flexible state, placing it into the duodenum through the nasal cavity and pushing it to the duodenum by relying on the intestinal peristalsis; an active intervention step: after the catheter body reaches the duodenum, driving the sealing block to rotate around the center shaft by operating the driving mechanism arranged on the handle outside the body, actively increasing the bending rigidity of the catheter body and making it produce a rotating movement, so as to assist the catheter to pass through the curved part of the intestinal tract and prevent it from being wound, until the front end of the catheter reaches the target obstruction position.

9. The method of claim 8, wherein, In the active intervention step, the rigidity adjusting tube in the catheter body is injected with fluid by the syringe pump to increase the internal pressure of the rigidity adjusting tube, so as to increase the bending rigidity of the catheter.

10. The method of claim 9, wherein, In the active intervention step, the catheter body is driven to rotate by rotating a rotating handle, and the rotating action is automatically converted into extrusion of fluid in the rigidity adjustment tube by a pressure boosting mechanism, so as to realize synchronous increase of the bending stiffness of the catheter while rotating propulsion.

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