Stiffness-adjustable gastric bypass stent conveying device and stent conveying system

Abstract

The invention relates to a stomach bypass stent conveying device with adjustable rigidity and a stent conveying system, and relates to the field of medical instruments, the stomach bypass stent conveying device with adjustable rigidity comprises a release ball, a storage tube, an outer tube, a handle and an adjusting core rod; when the adjusting core rod is inserted into the storage tube without the handle and abuts against and releases the small ball, the gastric bypass stent conveying device with the adjustable rigidity is in a flexible state; when the adjusting core rod is inserted into the storage tube through the handle and abuts against the release ball, the stomach bypass stent conveying device with the adjustable rigidity is in a rigid state. The adjusting core rod comprises a front-end hard rod and a rear-end soft rod which are connected with each other, and in the rigid state, the front-end hard rod is overlapped with the containing pipe and part of the outer pipe. According to the stomach bypass stent conveying device with the adjustable rigidity, the rigidity of the stomach bypass stent conveying device with the adjustable rigidity is changed by adjusting the core rod, the storage tube can easily enter a scotodoor, the rear-end soft rod can continue to protect the throat and esophagus of a patient, and the stomach bypass stent conveying device has both operability and safety.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular, to an adjustable-stiffness gastric bypass stent delivery device and a stent delivery system. Background Art

[0002] In existing gastric bypass stent delivery devices, the delivery device needs to first pass through the patient's throat, and then pass through the esophagus, cardia, and stomach respectively and finally reach the duodenal pylorus. Since it needs to pass through the throat, most components of the delivery device are designed as flexible parts to protect the patient's throat and esophagus. However, when the front end of the delivery device enters the stomach, although the flexible part can effectively protect the patient's throat and esophagus, it is of no help for the gastric bypass stent delivery device to smoothly enter the pylorus. The greater curvature of the stomach in obese patients is more curved than that of normal people. When the front end of the delivery device enters the stomach, the design of the flexible part will inevitably cause the outer tube of the device to travel along the greater curvature of the patient's stomach ( Figure 1 (a) in the figure). Once the outer tube of the delivery device travels along the greater curvature of the stomach, the force transmitted from the outside to the delivery device will only cause the outer tube to continue to coil in the stomach, rather than continue to push the receiving tube into the pylorus, and the force cannot be effectively transmitted, which brings great inconvenience to the surgical operation.

[0003] The current clinical solution is to use a foreign body forceps to clamp the green part of the receiving tube to increase the system stiffness so as to realize the pushing of the receiving tube and finally reach the pylorus. Using a foreign body forceps to push the receiving tube has certain skills in clinical use. Clamping the green connecting cap with a foreign body forceps will increase the operation difficulty and time, and requires a long operation time. At the same time, an additional medical staff is needed to operate the foreign body forceps.

[0004] In view of this, the present application is specifically proposed. Summary of the Invention

[0005] The object of the present application is to provide an adjustable-stiffness gastric bypass stent delivery device and a stent delivery system. When the adjustable-stiffness gastric bypass stent delivery device and the stent delivery system are in use, the adjustment mandrel is not installed in the adjustable-stiffness gastric bypass stent delivery device first, and the design of its flexible part can help the adjustable-stiffness gastric bypass stent delivery device protect the patient's throat and esophagus and enter the patient's stomach. When the receiving tube reaches the stomach, the adjustment mandrel is inserted into the lumen of the outer tube of the adjustable-stiffness gastric bypass stent delivery device from the hard section. Since the adjustment mandrel is harder than the outer tube, the stiffness of the entire adjustable-stiffness gastric bypass stent delivery device can be improved. After the stiffness of the adjustable-stiffness gastric bypass stent delivery device is improved, the pushing force applied from the outer tube at the handle end can be well transmitted to the receiving tube, making it easier for the receiving tube to enter the pylorus.

[0006] In a first aspect, the present application provides an adjustable stiffness gastric bypass stent delivery device, which includes a release ball, a receiving tube, an outer tube, a handle, and an adjustment mandrel; the cylindrical end of the release ball is inserted into the receiving tube, a stent pusher is slidably arranged in the receiving tube, the release ball is connected to a membrane tube on the stent pusher through a dissolvable inner core, the receiving tube is connected to the outer tube, and the outer tube is connected to the handle;

[0007] When the adjustment mandrel is inserted into the receiving tube through the handle and abuts against the release ball, the adjustable stiffness gastric bypass stent delivery device is in a flexible state; when the adjustment mandrel is inserted into the receiving tube through the handle and abuts against the release ball, the adjustable stiffness gastric bypass stent delivery device is in a rigid state;

[0008] The adjustment mandrel includes a front hard rod and a rear soft rod connected to each other. In the rigid state, the front hard rod overlaps with the receiving tube and part of the outer tube.

[0009] In an optional embodiment, the front hard rod is a metal hollow tube, and spiral grooves are provided throughout the front hard rod.

[0010] In an optional embodiment, the groove depth of the spiral groove is 0.2 - 0.3 mm, the groove width is 0.08 - 0.12 mm, and the pitch is 10 - 11 mm.

[0011] In an optional embodiment, the length of the front hard rod is the sum of 1 / 2 - 2 / 3 of the total length of the receiving tube and the total length of the outer tube.

[0012] In an optional embodiment, the elastic modulus of the front hard rod is 800 - 2000 MPa, and the elastic modulus of the rear soft rod is 20 - 500 MPa.

[0013] In an optional embodiment, the rear soft rod is made of plastic.

[0014] In an optional embodiment, the front hard rod and the rear soft rod are integrally formed by injection molding or glued.

[0015] In an optional embodiment, a knob and a locking wire are provided on the handle. The outer tube is a double-channel pipe, which includes an outer tube wall and an inner tube wall arranged coaxially. A first hollow channel for the locking wire to pass through is formed between the outer tube wall and the outer wall of the inner tube wall, and a second hollow channel for the adjustment mandrel to pass through is formed by the inner tube wall. One end of the locking wire is fixed to the knob, and the other end passes through the first hollow channel and is connected to the release ball.

[0016] In an alternative embodiment, the adjustable stiffness gastric bypass stent delivery device further includes a handle and an inner sliding rod for pushing the stent pusher block. The inner sliding rod has a hollow structure and sequentially passes through and is slidably disposed within the handle, the outer tube, and the receiving tube. One end of the inner sliding rod is fixedly connected to the handle, and the other end is fixedly connected to the stent pusher block. The adjustment core rod is selectively inserted into the inner sliding rod.

[0017] In a second aspect, the present application provides a stent delivery system, which includes a gastroscope, a guide wire, and an adjustable stiffness gastric bypass stent delivery device according to any one of the foregoing embodiments. The gastroscope is used to guide the guide wire, and after the gastroscope is withdrawn, the guide wire cooperates with the central cavity of the release ball of the adjustable stiffness gastric bypass stent delivery device and guides the movement of the adjustable stiffness gastric bypass stent delivery device.

[0018] The adjustable stiffness gastric bypass stent delivery device provided by the present application has the following beneficial effects:

[0019] The adjustable stiffness gastric bypass stent delivery device provided by the present application introduces an adjustment core rod, which is designed with a front hard rod and a rear soft rod. During use, the hard section overlaps with the receiving tube and part of the outer tube of the delivery device, and the remaining part is the soft section. When the adjustment core rod is not used, the delivery device is in a flexible state, which protects the patient's pharynx and esophagus. After inserting the adjustment core rod, the part of the adjustable stiffness gastric bypass stent delivery device from the receiving tube to the middle of the outer tube changes from a flexible member to a relatively rigid member, which is beneficial to improving the front-end rigidity. After the rigidity of the adjustable stiffness gastric bypass stent delivery device is improved, the pushing force applied from the outer tube at the handle end can be well transmitted to the receiving tube, making it easier for the receiving tube to enter the pylorus. Compared with the traditional method of pushing the receiving tube with a foreign body forceps, the present application simplifies the operation steps, reduces the doctor's operation time, and can also reduce one operator. The rear soft rod can continue to protect the patient's pharynx and esophagus, and the present application combines operability and safety. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a simulation schematic diagram when the receiving tube enters the pylorus of the patient. Among them, (a) is a simulation schematic diagram when the receiving tube and the outer tube travel along the greater curvature of the patient's stomach, and (b) is a simulation schematic diagram of the ideal pushing angle when the receiving tube and the outer tube enter the patient's pylorus;

[0022] Figure 2 Schematic structural diagram of the adjustable-stiffness gastric bypass stent delivery device provided by the present application in a flexible state;

[0023] Figure 3 Schematic structural diagram of the adjustable-stiffness gastric bypass stent delivery device provided by the present application in a rigid state;

[0024] Figure 4 Schematic structural diagram of the adjustment mandrel in the adjustable-stiffness gastric bypass stent delivery device provided by the present application;

[0025] Figure 5 Evaluation test model diagram of the stiffness of the outer tube of the delivery device in the experimental example provided by the present application.

[0026] Icon: 10 - release ball; 20 - receiving tube; 30 - locking wire; 40 - connecting cap; 50 - outer tube; 60 - handle; 70 - knob; 80 - handle; 90 - adjustment mandrel; 901 - front hard rod; 902 - rear soft rod; 903 - spiral groove; 100 - stent pusher; 110 - internal sliding rod. Detailed implementation manners

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0028] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this application is usually placed when in use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. In addition, terms such as "first", "second", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present application, it should also be noted that unless otherwise clearly defined and limited, the terms "set", "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0030] Please refer to Figure 2 and Figure 3 , this application provides a gastric bypass stent delivery device with adjustable stiffness, which includes a release ball 10, a receiving tube 20, an outer tube 50, a handle 60 and a handle 80.

[0031] The cylindrical end of the release ball 10 is inserted into the receiving tube 20. A stent pusher 100 is slidably arranged in the receiving tube 20. The release ball 10 is connected to the membrane tube on the stent pusher 100 through a dissolvable inner core. The receiving tube 20 is connected to the outer tube 50, the outer tube 50 is connected to the handle 60, the handle 80 is located at one end of the handle 60 away from the outer tube 50, and the handle 60 and the handle 80 are not directly connected. The handle 80 can move within a certain range. The connections described in this application can be glue bonding, threaded connection or mechanical press-fit connection.

[0032] Among them, the release ball 10 is a spherical structure, and one end of it is provided with a cylindrical end, which is used to insert into the receiving tube 20 to block the covered stent in the receiving tube 20. The release ball 10 and the receiving tube 20 are in clearance fit. The release ball 10 can be separated from the receiving tube 20 under the push of an external force to achieve the unlocked state. The locked state means that the release ball 10 remains fixed at the end of the receiving tube 20 and they cannot be separated by an external force. The unlocked state means that the release ball 10 and the end of the receiving tube 20 can be separated under the action of an external force.

[0033] In this embodiment, a covered stent (not shown in the figure) and a stent pusher 100 are arranged in the receiving tube 20. The covered stent is installed on the stent pusher 100, and the covered stent is connected to the release ball 10 through a dissolvable inner core.

[0034] The outer tube 50 is a double-channel pipe, which includes an outer pipe wall (not labeled in the figure) and an inner pipe wall (not labeled in the figure) arranged coaxially. A first hollow channel (not labeled in the figure) for the locking wire 30 to pass through is formed between the outer walls of the outer pipe wall and the inner pipe wall, and the inner pipe wall forms a second hollow channel (not labeled in the figure) for the adjusting core rod 90 to pass through. The receiving tube 20 and the outer tube 50 are connected through a connecting cap 40.

[0035] The handle 60 is used to lock and release the release ball 10. Specifically, a knob 70 and a locking wire 30 are provided on the handle 60. One end of the locking wire 30 is fixed to the knob 70, and the other end passes through the first hollow channel and is connected to the release ball 10. When the knob 70 fixes the locking wire 30, at this time, the relative position of the release ball 10 is fixed, and the release ball 10 remains fixed at the end of the receiving tube 20, and external force cannot separate them, presenting a locked state. When it is necessary to release the release ball 10, turn the knob 70 open. At this time, the locking wire 30 is in a free state, and by pushing the inner sliding rod 110 of the handle 80, the release ball 10 can be released, presenting an unlocked state.

[0036] The handle 80 is used to push the support push block 100 under the action of external force. An inner sliding rod 110 is fixedly arranged inside the handle 80. The inner sliding rod 110 is of a hollow structure, and it sequentially passes through and is slidably arranged inside the handle 60, the outer tube 50, and the receiving tube 20. One end of the inner sliding rod 110 is fixedly connected to the handle 80, and the other end is fixedly connected to the support push block 100. The connection between the inner sliding rod 110 and the handle 80 and the support push block 100 can be integrally formed by injection molding, glued connection, etc. During operation, the inner sliding rod 110 can be driven by the handle 80 to move inside the handle 60, the outer tube 50, and the receiving tube 20, so as to push the pushing support inside the receiving tube 20 to slide inside the receiving tube 20, and further realize the release of the release ball 10.

[0037] Due to the relatively soft structure and material, the force transmitted from the outside to the conveying device will only cause the outer tube 50 to continue to coil inside the stomach, rather than continue to push the receiving tube 20 into the pylorus.

[0038] For this reason, please refer to Figure 4 This application introduces an adjusting core rod 90, and the hardness of the adjustable stiffness gastric bypass stent conveying device can be adjusted by using this adjusting core rod 90.

[0039] Please refer to Figure 2 、 Figure 3 and Figure 4 Specifically, the adjusting core rod 90 includes a front hard rod 901 and a rear soft rod 902 that are connected to each other. The diameter of the adjusting core rod 90 is relatively small, and it needs to meet the requirement of being able to sequentially pass through the hollow structures such as the handle 80, the inner sliding rod 110, the handle 60, the outer tube 50, and the receiving tube 20.

[0040] When the adjusting core rod 90 is not inserted into the receiving tube 20 through the handle 60 and abuts against the release ball 10, the adjustable stiffness gastric bypass stent delivery device is in a flexible state; when the adjusting core rod 90 is inserted into the receiving tube 20 through the handle 60 and abuts against the release ball 10, the adjustable stiffness gastric bypass stent delivery device is in a rigid state. In the rigid state, the front hard rod 901 overlaps with the receiving tube 20 and part of the outer tube 50. Preferably, the length of the front hard rod 901 is the sum of the full length of the receiving tube 20 and 1 / 2 - 2 / 3 of the full length of the outer tube 50.

[0041] In this application, by setting the adjusting core rod 90 in the receiving tube 20 and part of the outer tube 50 as the front hard rod 901, it can increase the hardness of the receiving tube 20 and part of the outer tube 50. The increase in hardness enables the front end of the adjustable stiffness gastric bypass stent delivery device to have a certain rigidity, and the pushing force applied from the outer tube 50 at the handle 60 end can be well transmitted to the receiving tube 20( Figure 3 ), making it easier for the receiving tube 20 to enter the pylorus. And the rest are all rear soft rods 902, which can continue to protect the patient's throat and esophagus.

[0042] In this application, the front hard rod 901 is a metal hollow tube, and spiral grooves 903 are provided throughout the front hard rod 901. By providing spiral grooves 903 throughout the front hard rod, the front hard rod 901 can have a certain bending performance and at the same time have good force transmission ability. The setting method of the spiral grooves 903 will have a certain impact on the performance of the front hard rod. In this embodiment, the groove depth of the spiral grooves 903 is 0.2 - 0.3 mm, the groove width is 0.08 - 0.12 mm, and the pitch is 10 - 11 mm. Preferably, the groove depth of the spiral grooves 903 is 0.25 mm, the groove width is 0.1 mm, and the pitch is 10.5 mm. Through the above settings, the elastic modulus of the front hard rod 901 can be maintained at 800 - 2000 MPa.

[0043] The rear soft rod 902 is made of plastic material, and the plastic material includes but is not limited to at least one of silicone rubber, TPU, and PE. Using the above plastic material can ensure that the elastic modulus of the rear soft rod 902 is 20 - 500 MPa. By comparing the elastic moduli of the front hard rod 901 and the rear soft rod 902, it can be seen that the elastic modulus of the front hard rod 901 is greater and the material is not easily deformed.

[0044] In some embodiments, the front hard rod 901 and the rear soft rod 902 are integrally formed by injection molding or glued.

[0045] The working principle of the adjustable - stiffness gastric bypass stent delivery device provided in this embodiment is as follows: The adjustable - stiffness gastric bypass stent delivery device is first used in a flexible state (i.e., the state without inserting the adjustment core rod 90). The flexible setting of the adjustable - stiffness gastric bypass stent delivery device itself enables the device to pass through the patient's pharynx and enter the patient's stomach, and the flexible setting can protect the pharynx. When the release ball 10 and the receiving tube 20 reach the stomach, the front hard rod 901 of the adjustment core rod 90 is passed through the handle 80, the internal sliding rod 110, the handle 60, the outer tube 50, and the receiving tube 20 in sequence and abuts against the release ball 10. Since the adjustment core rod 90 is harder than the outer tube 50, the rigidity of the entire delivery device can be increased. After the rigidity of the adjustable - stiffness gastric bypass stent delivery device is increased, the pushing force applied from the outer tube 50 at the handle 60 end can be well transmitted to the receiving tube 20, making it easier for the receiving tube 20 to enter the pylorus. When the receiving tube 20 enters the pylorus (please refer to Figure 1 in (b)), the locking wire 30 can be released by using the knob 70 on the handle 60. Then, the handle 80 is pushed, and the handle 80 drives the internal sliding rod 110 to slide within the handle 60, the outer tube 50, and the receiving tube 20, thereby pushing the stent pusher 100 to realize the release of the release ball 10.

[0046] In addition, this application provides a stent delivery system, which includes a gastroscope, a guide wire, and the above - mentioned adjustable - stiffness gastric bypass stent delivery device. The gastroscope is used to guide the guide wire. After the gastroscope is withdrawn, the guide wire cooperates with the hollow guiding through - hole of the release ball 10 of the adjustable - stiffness gastric bypass stent delivery device and guides the movement of the adjustable - stiffness gastric bypass stent delivery device. When the adjustable - stiffness gastric bypass stent delivery device moves to a specific position, the guide wire is withdrawn, and the unlocking operation is performed according to the above - mentioned method.

[0047] Embodiment 1

[0048] The structure of the adjustment core rod 90 in the adjustable - stiffness gastric bypass stent delivery device of this embodiment is as follows: The front hard rod 901 is a metal hollow tube, and a spiral groove 903 is provided throughout the front hard rod 901. The groove depth of the spiral groove 903 is 0.25 mm, the groove width is 0.1 mm, the pitch is 10.5 mm, the elastic modulus of the front hard rod 901 is 800 - 2000 MPa, the rear soft rod 902 is made of silicone plastic material, and the elastic modulus of the rear soft rod 902 is about 300 MPa. The length of the front hard rod 901 is the sum of the full length of the receiving tube 20 and two - thirds of the full length of the outer tube 50. For other structures of the adjustable - stiffness gastric bypass stent delivery device, please refer to the above description.

[0049] Comparative Example 1

[0050] This comparative example provides an adjustable stiffness gastric bypass stent delivery device without using the adjusting mandrel 90.

[0051] Comparative Example 2

[0052] This comparative example is basically the same as Example 1, except that in this comparative example, the adjusting mandrel 90 is not provided with a threaded groove.

[0053] Comparative Example 3

[0054] This comparative example is basically the same as Example 1, except that in this comparative example, the groove depth of the helical groove 903 of the adjusting mandrel 90 is 0.25 mm, the groove width is 0.1 mm, and the pitch is 3 mm. At this time, the elastic modulus of the front hard rod 901 is 150 - 350 MPa.

[0055] Experimental Example

[0056] This application adopts Figure 5 a stiffness evaluation test model, that is, a certain span is set for the outer tube 50 of the adjustable stiffness gastric bypass stent delivery device. The outer tube 50 of the adjustable stiffness gastric bypass stent delivery device is fixed at one end of the test model, and the other end is in a slidable state. A force is applied in the middle of the outer tube 50. When the outer tube 50 displaces downward by 10 mm, the force value applied by the tensile testing machine at this time is recorded. Stiffness refers to the ability of a product to resist deformation. In this case, the difference in rigidity is evaluated by comparing the reaction forces of different schemes on the testing machine under the same test conditions. Please refer to Table 1 for the test results.

[0057] Table 1. Test results of the force of the outer tube 50 of the adjustable stiffness gastric bypass stent delivery device in different examples to resist deformation

[0058]

[0059]

[0060] As can be seen from the above table, after the implementation of this application, when the outer tube 50 of the delivery device displaces downward by 10 mm, the average value of the force to resist deformation is 19.04 N, while in Comparative Example 1, when the outer tube 50 of the delivery device without using the adjusting mandrel 90 displaces downward by 10 mm, the average value of the force to resist deformation is 8.77 N. It can be seen that the method of increasing the stiffness in this application has a significant increase in the force to resist deformation compared to before. In Comparative Example 2, when the outer tube 50 of the delivery device using the adjusting mandrel 90 (without a threaded groove) displaces downward by 10 mm, the average value of the force to resist deformation is 30.92 N. In Comparative Example 3, when the outer tube 50 of the delivery device using the adjusting mandrel 90 (with a thread pitch of 3 mm) displaces downward by 10 mm, the average value of the force to resist deformation is 12.27 N.

[0061] In summary, the adjustable stiffness gastric bypass stent delivery device provided by the present application introduces an adjustment mandrel 90, which is designed with a front hard rod 901 and a rear soft rod 902. During use, the hard section overlaps with the receiving tube 20 and part of the outer tube 50 of the delivery device, and the remaining part is the soft section. When the adjustment mandrel 90 is not used, the delivery device is in a flexible state, which protects the patient's pharynx and esophagus. After inserting the adjustment mandrel 90, the part of the adjustable stiffness gastric bypass stent delivery device from the receiving tube 20 to the middle of the outer tube 50 changes from a flexible member to a relatively rigid member, which is beneficial to improving the front-end rigidity. After the rigidity of the adjustable stiffness gastric bypass stent delivery device is improved, the pushing force applied from the outer tube 50 at the handle 60 end can be well transmitted to the receiving tube 20, making it easier for the receiving tube 20 to enter the pylorus. Compared with the traditional method of pushing the receiving tube 20 with a foreign body forceps, the present application simplifies the operation steps, reduces the operation time of the doctor, and can also reduce one operator. The rear soft rod 902 can continue to protect the patient's pharynx and esophagus. The hard section of the adjustment mandrel 90 of the present application is designed with a metal hollow tube and is integrally designed with a spiral groove 903. This design can, on the one hand, enable the hard section to have a certain bending performance, and on the other hand, have good force transmission ability.

[0062] It should be noted that, without conflict, the features in the embodiments of the present application can be combined with each other.

[0063] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An adjustable stiffness gastric bypass stent delivery device, characterized in that It includes a release ball, a storage tube, an outer tube, a handle and an adjusting core rod; the cylindrical end of the release ball is inserted into the storage tube, a bracket push block is slidably arranged in the storage tube, the release ball is connected to the membrane tube on the bracket push block through a dissolvable inner core, the storage tube is connected to the outer tube, and the outer tube is connected to the handle; When the adjusting core rod is inserted into the storage tube through the handle and abuts against the release ball, the adjustable stiffness gastric bypass stent delivery device is in a flexible state; when the adjusting core rod is inserted into the storage tube through the handle and abuts against the release ball, the adjustable stiffness gastric bypass stent delivery device is in a rigid state; The adjusting core rod includes a front hard rod and a rear soft rod which are connected to each other. In the rigid state, the front hard rod overlaps with the storage tube and part of the outer tube.

2. The adjustable stiffness gastric bypass stent delivery device according to claim 1, characterized in that The front hard rod is a metal hollow tube, and spiral grooves are arranged on the whole front hard rod.

3. The adjustable stiffness gastric bypass stent delivery device according to claim 2, wherein The groove depth of the spiral groove is 0.2-0.3 mm, the groove width is 0.08-0.12 mm, and the pitch is 10-11 mm.

4. The adjustable stiffness gastric bypass stent delivery device according to claim 1, wherein The length of the front hard rod is the sum of half to two-thirds of the total length of the storage tube and the total length of the outer tube.

5. The adjustable stiffness gastric bypass stent delivery device according to claim 1, wherein The elastic modulus of the front hard rod is 800-2000 MPa, and the elastic modulus of the rear soft rod is 20-500 MPa.

6. The adjustable stiffness gastric bypass stent delivery device according to claim 1, wherein The rear soft rod is made of plastic.

7. The adjustable stiffness gastric bypass stent delivery device according to claim 1, characterized in that, The front hard rod and the rear soft rod are integrally formed by injection molding or glued.

8. The adjustable stiffness gastric bypass stent delivery device according to claim 1, characterized in that A knob and a locking wire are arranged on the handle. The outer tube is a double-channel pipe, which includes an outer tube wall and an inner tube wall arranged coaxially. A first hollow channel for the locking wire to pass through is formed between the outer tube wall and the outer wall of the inner tube wall, and a second hollow channel for the adjusting core rod to pass through is formed by the inner tube wall. One end of the locking wire is fixed on the knob, and the other end passes through the first hollow channel and is connected to the release ball.

9. The adjustable stiffness gastric bypass stent delivery device according to claim 1, characterized in that, The adjustable stiffness gastric bypass stent delivery device further includes a handle and an internal sliding rod for pushing the bracket push block. The internal sliding rod is a hollow structure, which sequentially passes through and is slidably arranged in the handle, the outer tube and the storage tube. One end of the internal sliding rod is fixedly connected to the handle, and the other end is fixedly connected to the bracket push block. The adjusting core rod can be selectively inserted into the internal sliding rod.

10. A stent delivery system, characterized in that, It includes a gastroscope, a guide wire and the adjustable stiffness gastric bypass stent delivery device according to any one of claims 1-9. The gastroscope is used to guide the guide wire. After the gastroscope is withdrawn, the guide wire cooperates with the central cavity of the release ball of the adjustable stiffness gastric bypass stent delivery device and guides the movement of the adjustable stiffness gastric bypass stent delivery device.

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