CN216724895U - Vascular stent delivery system - Google Patents

Abstract

The utility model provides a vascular stent delivery system, it includes: the catheter unit comprises an outer tube and an inner tube unit arranged in the outer tube, the inner tube unit comprises an inner tube and a stent pushing unit arranged on the inner tube, and a loading area for accommodating the intravascular stent is arranged between the inner tube unit and the outer tube and in front of the stent pushing unit; the conveying unit comprises a driving handle, a locking mechanism and a transmission unit arranged in the shell, the transmission unit comprises a rotating gear set, a rear driving rack and a front driving rack, and the rear driving rack and the front driving rack are both meshed with the rotating gear set; the rear driving rack is connected with the driving handle, the front driving rack is connected with the outer pipe, and a push rod connected with the inner pipe is arranged in the driving handle; the driving handle is sleeved on the shell in a sliding mode, and the locking mechanism is arranged on the driving handle and used for locking and releasing the driving handle and the shell. The utility model discloses well user only operates the drive handle and can realize the transport of vascular support, is convenient for realize.

Description

Vascular stent delivery system

technical field

The utility model relates to the technical field of medical devices, in particular to a delivery system for a blood vessel stent.

Background technique

Taking the intervention of peripheral vascular stents as an example, the implantation of vascular stents requires the use of a delivery device. In the prior art, for example, CN201110190183.4 discloses a delivery device, which adopts a hollow inner tube and an outer tube that are sleeved with each other, and the vascular stent is arranged in the Between the inner tube and the outer tube, the inner tube is a hollow structure, and its inner lumen is convenient for the guide wire to penetrate during the operation; during the operation, the delivery device transports the catheter unit to the operation area through the guidance of the guide wire, and the control unit makes the outer tube pass through. It moves relative to the inner tube. During the process, the vascular stent expands and adheres to the inner wall of the blood vessel to play a supporting role.

The axial length of the stent deployed in the human lumen is recorded as L1, and the axial length of the stent in the compressed state in the outer tube is recorded as L2. Generally, L1 is less than L2. Therefore, the ratio of the difference between the two lengths to L2 is called the stent shortening ratio. . For the delivery and release method of the self-expanding stent disclosed in CN201110190183.4, when the shortening rate of the stent in the human lumen is zero or relatively small (for example, less than 3%), the stent will generally not be positioned and released during the stent positioning and release process. There are too many problems. However, for stents with a large shortening rate, especially the highly shortened stents woven with NiTi wire (more than 30%), the above-mentioned release methods have many defects, 1): this simple release method cannot guarantee stent release The actual position of the anterior anchor point and the stent anchor point after release coincide, causing the distal end of the stent to shift. Assuming that the length of the stent in the compressed state in the outer tube is L0, and the actual natural length released into the predetermined lumen is L1, the axial shortening of the stent is ΔL=L0-L1. Since the stent is axially shortened when the stent is released, and the proximal end of the stent is still compressed in the sheath of the delivery device and cannot move when the stent is not fully released, the anchor point at the distal end of the stent will move toward the proximal end with the shortening of the stent. After the stent is released, the distance of the distal positioning point can reach △L, resulting in inaccurate positioning of the stent, which brings great trouble to the operation and even causes the operation to fail. 2): Because the stent will undergo axial shortening during the release process, the distal part of the stent that has been attached to the wall will gradually move to the proximal end with the shortening of the stent in the human lumen (or there is a tendency to move in this way). This kind of movement is very likely to cause damage to the inner wall of the lumen. In addition, during the stent release process, because the distal end and proximal end of the stent are respectively restricted by the inner wall of the human lumen and the delivery device, the incompletely shortened stent will have an axial stretching effect, causing the gap between the stent and the inner wall of the human lumen. There is an axial force, and this pulling force can easily cause damage to the inner wall of the lumen.

Since the stent shortens during release, the delivery device cannot automatically adjust to accommodate this shortening. And CN201110183029.4 discloses a stent shortening self-adaptive delivery device, the delivery device designed in this patent can release the stent accurately, and there is no displacement between the stent and the lumen, which can avoid the damage of the stent to the human lumen. However, the conveying device has a complex structure and large transmission force, and requires a long operating handle for a long-sized bracket, which is very bulky and has a large driving force of the knob, which brings great inconvenience to the doctor's operation.

Therefore, there is a need for a vascular stent delivery system with a stent shortening adaptive function and a simple structure and easy operation.

Utility model content

In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a vascular stent delivery system, which is used to solve the problems of complicated and difficult operation of the vascular stent delivery mechanism in the prior art.

In order to achieve the above-mentioned purpose and other related purposes, the utility model provides a blood vessel stent delivery system, which comprises:

A catheter unit, comprising an outer tube and an inner tube unit arranged in the outer tube, the inner tube unit comprising an inner tube and a stent pushing unit placed on the inner tube, the inner tube unit and the outer tube and between the inner tube unit and the outer tube There is a loading area for accommodating the blood vessel stent in front of the stent pushing unit;

The conveying unit includes a driving handle, a locking mechanism and a transmission unit placed in the casing; the driving handle is connected with the catheter unit through the transmission unit, so as to drive the outer tube and the inner tube to move and the outer tube and the inner tube to move. The pipe moves in opposite directions; the driving handle is slidably sleeved on the housing, and the locking mechanism is provided on the driving handle for locking and releasing the driving handle and the housing.

Preferably, the locking mechanism includes a pressing piece, a locking block and a spring, the pressing piece is rotatably arranged on the driving handle, and one end of the pressing piece is in conflict with the locking block, and the spring supports the lock The block is used for keeping the locking block to lock the driving handle and the housing, and when the pressing piece is pressed, the pressing piece presses against the locking block to release the driving handle and the housing.

Preferably, the transmission unit includes a rotation gear set, a rear drive rack and a front drive rack, and both the rear drive rack and the front drive rack mesh with the rotation gear set; the rear drive rack is connected to the drive handle , the front drive rack is connected with the outer tube, and a push rod connected with the inner tube is fixed in the drive handle.

Preferably, the rotating gear set includes a rotating shaft arranged in the casing, a first gear and a second gear arranged on the rotating shaft, and the first gear meshes with the rear drive rack, The second gear meshes with the front drive rack.

Preferably, the gear ratios of the first gear and the second gear are different.

Preferably, the first gear or the second gear cooperates with the rotating shaft through a one-way clutch mechanism, and the front drive rack does not move when the drive handle drives the rear drive rack to move backwards.

Preferably, the push rod and the inner tube are both hollow structures and communicate with each other, the drive handle is provided with a through hole communicating with the push rod, and the front end of the inner tube is connected to a soft head.

Preferably, the transmission unit includes a rotating gear set, a rear drive rack, a front drive rack and a middle drive rack, and the rotating gear set includes a rotating shaft rotatably arranged in the housing and a rotating shaft arranged on the rotating shaft. A first gear, a second gear and an intermediate gear located between the first gear and the second gear, the first gear meshes with the rear drive rack, and the second gear meshes with the front drive rack , the intermediate gear is connected with the middle drive rack; the middle drive rack is connected with the drive handle, the front drive rack is connected with the outer tube, and the drive handle is fixed with the The push rod to which the inner tube is connected.

Preferably, the first gear or the second gear is matched with the rotating shaft through a one-way clutch mechanism, and when the driving handle drives the middle drive rack to move backwards, the rear drive rack simultaneously moves toward the rear. Rear movement, but the front drive rack does not move.

Preferably, the transmission unit includes a rotating gear set, a rear drive rack and a front drive rack, and the rotating gear set includes a rotating shaft disposed in the housing and a single gear disposed on the rotating shaft, so One side of the single gear meshes with the rear drive rack, and the other side of the single gear meshes with the front drive rack indirectly or directly.

Preferably, the conduit unit further includes a hollow tube arranged in the inner tube, the hollow tube is fixedly connected to the outer shell, and the front end of the hollow tube is connected to a soft head.

Preferably, the bracket pushing unit is one or more sets of claws arranged around the inner tube circumferentially.

Preferably, the stent pushing unit is in the shape of a round tube or a plum blossom.

As described above, the vascular stent delivery system of the present invention has the following beneficial effects: by unlocking the drive handle, the drive handle is reciprocated relative to the outer casing, and the rear drive rack and push rod are driven to move and then the inner tube moves forward and outward. The tube moves backward, and the vascular stent located in the loading area is pushed out and positioned by the stent pushing unit; the user can realize the delivery of the vascular stent only by operating the driving handle, which is convenient for implementation.

Description of drawings

FIG. 1 shows the overall schematic diagram of the stent delivery system of the present invention.

FIG. 2 shows a schematic diagram of an embodiment of the inner tube unit of the present invention.

FIG. 3 is a schematic diagram of another embodiment of the inner tube unit in the present invention.

FIG. 4 shows a schematic diagram of the conveying unit of the present invention.

FIG. 5 shows a schematic diagram of the rotating gear set of the present invention.

FIG. 6 shows a schematic diagram of the drive handle of the present invention.

Component label description

10 Conduit unit

11 Inner tube unit

20 drive unit

30 Turn the gear set

40 Drive handle

100 soft tips

110 Connecting tube

120 Bracket Push Unit

130 jaws

140 inner tube

150 outer tube

210 Outer Fitting

220 front drive rack

230 rear drive rack

240 putter

250 gear slot

300 Rotary Axes

310 First gear

320 Second gear

410 Tablets

420 lock block

430 Spring

440 connection block

Detailed ways

The embodiments of the present invention are described below by specific embodiments, and those who are familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

See Figures 1 to 6. It should be noted that the structures, proportions, sizes, etc. shown in the accompanying drawings in this specification are only used to cooperate with the contents disclosed in the specification, so as to be understood and read by those who are familiar with this technology, and are not used to limit the implementation of the present invention. Therefore, it does not have technical substantive significance. Any modification of structure, change of proportional relationship or adjustment of size should still fall in It is within the scope that the technical content disclosed in the present invention can cover. At the same time, the terms such as "up", "down", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and clarity, and are not used to limit this specification. The applicable scope of the utility model and the change or adjustment of its relative relationship shall be regarded as the applicable scope of the present utility model without substantially changing the technical content.

For ease of description, the axial direction of the catheter unit is referred to as the front-to-back direction in this specification, the end close to the user (ie, the rotating handle) is referred to as the rear or proximal end, and the end away from the user is referred to as the front or distal end.

Example 1

As shown in Figure 1 to Figure 6, the present invention provides a blood vessel stent delivery system, which includes:

The catheter unit 10 includes an outer tube 150 and an inner tube unit 11 disposed in the outer tube. The inner tube unit 11 includes an inner tube 140 and a stent pushing unit 120 placed on the inner tube 140. The inner tube unit 11 There is a loading area for accommodating vascular stents between the outer tube 150 and in front of the stent pushing unit 120;

The conveying unit includes a drive handle 40, a locking mechanism and a transmission unit 20 placed in the casing, the transmission unit 20 includes a rotating gear set 30, a rear drive rack 230 and a front drive rack 220, and the rear drive rack 230 and the front drive The racks 220 are all engaged with the rotating gear set 30 and the movement directions of the rear drive rack 230 and the front drive rack 220 are opposite; the rear drive rack 230 is connected to the drive handle 40 , and the front drive rack 220 is connected to the The outer tube 150 is connected to each other, and the push rod 240 connected to the inner tube in the inner tube unit 11 is fixedly penetrated in the driving handle 40; the driving handle 40 is slidably sleeved on the outer casing, and the locking mechanism On the drive handle 40, it is used to lock and release the drive handle 40 and the housing.

In this embodiment, the driving handle 40 and the housing are locked and released through the locking mechanism. The user only needs to unlock the locking mechanism, and then push and pull the driving handle 40 back and forth, so that the inner tube unit 11 and the outer tube 150 can be reversed. Forward movement, that is, the forward movement of the inner tube unit 11 drives the stent pushing unit 120 to push the vascular stent to the outside of the catheter unit 10, while the backward movement of the outer tube 150 is to move towards the proximal end, thereby completing the release of the vascular stent, and this implementation During the release process of the example blood vessel stent, the drive handle 40 drives the outer tube 150 to move backward through the transmission unit, that is, from the distal end to the proximal side, and the drive handle 40 drives the inner tube unit 11 while the outer tube 150 moves backwards. Always move forward, so that the released vascular stent can stick to the blood vessel wall in time, avoiding the problem that the released vascular stent is pulled by the delivery device and cannot adhere to the wall in time due to simply pulling the outer tube 150 to the proximal side. In addition, the driving force of the above-mentioned rotating handle is directly transmitted to the inner tube unit 11, and then transmitted to the outer tube 150 through the transmission gear set, and the required driving force is small, so it is easy to implement.

For ease of operation, as shown in FIGS. 4 and 6 , the locking mechanism in this embodiment includes a pressing piece 410 , a locking block 420 and a spring 430 . The pressing piece 410 is rotatably arranged on the driving handle 40 , and the pressing piece One end of 410 is in conflict with the lock block 420 , the spring 430 supports the lock block 420 and is used to keep the lock block 420 to lock the drive handle 40 and the housing, and press the pressing piece 410 When the pressing piece 410 presses against the locking block 420, the driving handle 40 and the housing are released. This embodiment can be unlocked only by pressing action, which is easy to operate; when there is no need to push or pull the drive handle 40, the lock block 420 locks the drive handle 40 and the housing under the elastic force of the spring 430 to avoid misoperation and improve the safety of the conveying system practicality.

In this embodiment, a specific embodiment of the locking block 420 locking the driving handle 40 and the housing may be: a slot is provided on the driving handle 40, the locking block 420 is connected to the housing, and when the pressing force 410 is not pressed, the The lock block 420 is lifted by the spring 430 and clamped in the card slot. When the pressing piece 410 is pressed, the spring 430 is compressed and the lock block 420 is lowered and separated from the card slot, then the drive handle 40 and the housing are unlocked, and the pressing piece can be pressed. Push and pull the drive handle 40 .

The above-mentioned locking mechanism is not limited to this, and can be other clutch mechanisms, as long as the driving handle and the housing can be locked and unlocked under operation.

In order to control the pushing speed and reduce the driving force of the push-pull drive handle 40, as shown in FIG. 5, in this embodiment, the above-mentioned rotating gear set 30 includes a rotating shaft 300 disposed in the casing and a rotating shaft 300 disposed on the rotating shaft. The first gear 310 and the second gear 320 on the 300 , the first gear 310 meshes with the rear drive rack 230 , and the second gear 320 meshes with the front drive rack 220 . Further, the gear ratios of the first gear 310 and the second gear 320 are different. In this embodiment, the rear drive rack 230 and the front drive rack 220 are arranged in parallel and offset, and the teeth on the rear drive rack 230 and the front drive rack 220 face oppositely.

The stent pushing unit 120 in the above-mentioned inner tube unit 11 may be a tube section with a plurality of claws 130 arranged in the circumferential direction, as shown in FIG. , as shown in FIG. 2 , it can also be in other convex shapes, such as a plum blossom shape; in this embodiment, the stent pushing unit 120 will not pull the vascular stent when it moves toward the proximal end.

In this embodiment, the inner tube unit 11 can be divided into multiple sections along the rear and front directions. The main section is the inner tube 140, and the proximal end of the inner tube 140 is connected to the push rod 240. In this embodiment, the inner tube 140 and the push rod 240 are both It is a hollow structure and communicates with each other. The above-mentioned driving handle is provided with a through hole that communicates with the push rod 240. The distal end of the inner tube 140 can be connected to a soft head 100 through the connecting tube 110. In this embodiment, the guide wire can be passed through the inner tube. In the unit 11, the catheter unit 10 is guided into the operation area, and the setting of the soft tip prevents the inner tube 140 from protruding out of the outer tube and injuring the blood vessel wall.

Example 2

The structure of the stent delivery system in this embodiment is similar to that in Embodiment 1. The difference is that the catheter unit 10 in Embodiment 1 only includes the inner tube unit 11 and the outer tube 150, and the inner tube unit 11 is a hollow lumen. , which is used to pass the guide wire during the operation, and the guide wire guides the catheter unit 10 into the operation area. The conduit unit 10 in this embodiment may further include a hollow tube disposed in the inner tube unit 11 . The hollow tube penetrates the inner tube and can move relative to the inner tube and is fixedly connected to the outer shell. The front end of the tube is connected to a soft head. By adding a hollow tube, the guide wire passes through the hollow tube to guide the catheter unit. During the operation, the hollow tube and the soft head can be fixed, and the driving handle 40 only drives the inner tube and the outer tube. The tube moves, reducing damage to the vessel wall.

Example 3

In order to adapt to vascular stents of different lengths, as shown in FIG. 4 , in this embodiment, on the basis of the above-mentioned Embodiment 1 and Embodiment 2, a gear slot 250 is provided on the inner wall of the above-mentioned outer casing, and the above-mentioned rear drive rack 230 is provided with a gear slot 250 . There is an external convex part, and the cooperation between the external convex part and the gear slot 250 is convenient to lock the rear drive rack 230, and to know its moving distance, which is convenient for the user to judge whether the blood vessel stent is pushed in place.

The specific structure of the vascular stent delivery system in this embodiment is as follows: the outer tube 150 is connected to the front drive rack 220 through the outer tube joint 210, the end of the inner tube 140 extends into the casing and is connected to the push rod 240, and the push rod 240 is pushed. Both the rod 240 and the above-mentioned rear drive rack 230 are connected to the connecting block 440 in the drive handle 40 .

During the operation, insert the guide wire into the hollow tube in the catheter unit 10, or directly into the inner tube if there is no hollow tube, press the above-mentioned pressing piece 410, unlock the driving handle 40 and the above-mentioned outer casing, and push the driving handle 40 forward, The drive handle 40 drives the rear drive rack 230 to move forward, and the rear drive rack 230 drives the front drive rack 220 to move backward by rotating the gear set 30 , and the front drive rack 220 drives the outer tube 150 to move backward. At the same time, the handle 40 is driven by pushing The rod 240 pushes the inner tube unit 11 to move forward, and the stent pushing unit 120 in the inner tube unit 11 pushes the vascular stent to the outside of the catheter unit 10 to realize the release of the vascular stent. In this embodiment, the moving speed ratio of the driving handle 40 and the front drive rack 220 can be made equal to the ratio of the axial shortening of the delivered vascular stent to the natural length of the vascular stent, so as to further prevent the axial expansion and contraction of the vascular stent from affecting the blood vessel wall. Impact.

Example 4

In this embodiment, based on the above three embodiments, the above-mentioned driving handle can be reciprocated during the operation, so as to adapt to the release of vascular stents of different specifications. Even for large-sized vascular stents, the shell does not need to be enlarged. In this embodiment, the above-mentioned first gear or the second gear cooperates with the rotating shaft through a one-way clutch mechanism. When the driving handle drives the rear drive rack to move backwards, the front drive rack does not move. When the drive rack moves backward, due to the existence of the one-way clutch mechanism (such as one-way bearing), the front drive rack does not move, that is, the rear drive rack can move the outer tube forward, that is, the outer tube is only used in the operation. Backward movement, without forward movement, realizes that the drive handle is retracted and then pushed forward, and the vascular stent is released one by one, so that the smaller-sized delivery unit can meet the release of larger-sized vascular stents.

Example 5

The transmission unit in the above-mentioned embodiment can be replaced with the following structural form. The first gear, the second gear and the intermediate gear located between the first gear and the second gear on the rotating shaft, the first gear meshes with the rear drive rack, the second gear meshes with the front drive rack, and the intermediate gear meshes with the middle gear. The driving gear rack is connected; the middle driving gear rack is connected with the driving handle, the front driving gear rack is connected with the outer pipe, and a push rod connected with the inner pipe is fixed in the driving handle. In the transmission unit of this embodiment, a middle drive rack and an intermediate gear are added to realize the transmission between the drive handle and the rotating gear set, which is convenient for arrangement and installation.

More preferably, the first gear or the second gear in this embodiment is matched with the rotating shaft through a one-way clutch mechanism, and when the driving handle drives the middle drive rack to move backwards, the rear drive rack moves toward the rear at the same time. The rear moves, but the front drive rack doesn't move.

As another embodiment of the transmission unit, it may also include a rotating gear set, a rear drive rack and a front drive rack, and the rotating gear set includes a rotating shaft disposed in the housing and a rotating shaft disposed on the rotating shaft. One side of the single gear meshes with the rear drive rack, and the other side of the single gear meshes with the front drive rack indirectly or directly. The single gear in this embodiment can be a one-way rotating gear, which meshes with the front drive rack through a clutch mechanism. When the drive handle drives the middle drive rack to move backwards, the rear drive rack simultaneously moves backwards movement, but the action of the clutch mechanism disengages the engagement between the front drive rack and the single gear. The single gear in this embodiment can also be a bidirectional rotating gear, which directly meshes with the front drive rack, and when the driving handle drives the middle drive rack to move forward and backward, the rear drive rack moves in the opposite direction at the same time.

Therefore, the utility model effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

The above-mentioned embodiments merely illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims (13)

1. A vascular stent delivery system, comprising:

the catheter unit comprises an outer tube and an inner tube unit arranged in the outer tube, the inner tube unit comprises an inner tube and a stent pushing unit arranged on the inner tube, and a loading area for accommodating a vascular stent is arranged between the inner tube unit and the outer tube and in front of the stent pushing unit;

the conveying unit comprises a driving handle, a locking mechanism and a transmission unit arranged in the shell; the driving handle is connected with the catheter unit through the transmission unit so as to drive the outer tube and the inner tube to move, and the moving directions of the outer tube and the inner tube are opposite; the driving handle is sleeved on the shell in a sliding mode, and the locking mechanism is arranged on the driving handle and used for locking and releasing the driving handle and the shell.

2. The vascular stent delivery system of claim 1, wherein: the locking mechanism comprises a pressing sheet, a locking block and a spring, the pressing sheet is rotatably arranged on the driving handle, one end of the pressing sheet is abutted to the locking block, the spring supports the locking block and is used for keeping the locking block to lock the driving handle and the shell, and when the pressing sheet is pressed, the pressing sheet is abutted to the locking block to release the driving handle and the shell.

3. The vascular stent delivery system of claim 1, wherein: the transmission unit comprises a rotating gear set, a rear drive rack and a front drive rack, and the rear drive rack and the front drive rack are both meshed with the rotating gear set; the rear drive rack is connected with the drive handle, the front drive rack is connected with the outer tube, and a push rod connected with the inner tube is fixedly arranged in the drive handle.

4. The stent delivery system according to claim 3, wherein: the rotating gear set comprises a rotating shaft arranged in the shell, a first gear and a second gear, wherein the first gear and the second gear are arranged on the rotating shaft, the first gear is meshed with the rear driving rack, and the second gear is meshed with the front driving rack.

5. The stent delivery system according to claim 4, wherein: the gear ratios of the first gear and the second gear are different.

6. The vascular stent delivery system of claim 4, wherein: the first gear or the second gear is matched with the rotating shaft through a one-way clutch mechanism, and the front driving rack is not moved when the driving handle drives the rear driving rack to move backwards.

7. The stent delivery system according to claim 3, wherein: the push rod and the inner tube are both of hollow structures and communicated with each other, a via hole communicated with the push rod is formed in the driving handle, and the front end of the inner tube is connected with a soft head.

8. The stent delivery system according to claim 1, wherein: the transmission unit comprises a rotating gear set, a rear driving rack, a front driving rack and a middle driving rack, the rotating gear set comprises a rotating shaft which is rotatably arranged in the shell, a first gear, a second gear and an intermediate gear, the first gear, the second gear and the intermediate gear are arranged on the rotating shaft, the first gear is meshed with the rear driving rack, the second gear is meshed with the front driving rack, and the intermediate gear is connected with the middle driving rack; the middle driving rack is connected with the driving handle, the front driving rack is connected with the outer tube, and a push rod connected with the inner tube is fixedly arranged in the driving handle.

9. The vascular stent delivery system of claim 8, wherein: the first gear or the second gear is matched with the rotating shaft through a one-way clutch mechanism, when the driving handle drives the middle driving rack to move backwards, the rear driving rack moves backwards simultaneously, but the front driving rack does not move.

10. The stent delivery system according to claim 1, wherein: the transmission unit includes rotation gear group, back drive rack and front drive rack, rotation gear group is located including rotating the axis of rotation in the shell and locating epaxial single gear rotates, one side of single gear with back drive rack meshes mutually, the opposite side of single gear with the indirect or direct looks meshing of front drive rack.

11. The stent delivery system according to claim 1, wherein: the catheter unit also comprises a hollow tube arranged in the inner tube, the hollow tube is fixedly connected with the shell, and the front end of the hollow tube is connected with a soft head.

12. The stent delivery system according to claim 1, wherein: the support pushing unit is one or more groups of clamping jaws arranged around the circumferential direction of the inner pipe.

13. The stent delivery system according to claim 1, wherein: the support pushing unit is in a circular tube shape or a plum blossom shape.

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