A cannula structure for quantitatively injecting materials into the peritubal space

Abstract

The present invention relates to the technical field of medical devices, and specifically discloses a cannula structure for quantitatively injecting materials into the peritubal space of the eustachian tube. The cannula structure is composed of an inner tube and an outer tube nested with each other, and a quantitative component and a limiting component are integrated on the outer tube, and an airbag component is integrated on the inner tube. The airbag component is composed of an airbag, an air pump, a movable rod A, a movable rod B and a squeezing arc plate. By moving the inner tube forward, the airbag is moved to the outside of the outer tube, and the squeezing arc plate is triggered to squeeze the movable rod A, and the movable rod A then pulls the movable rod B to squeeze the piston to move in the air pump, and the liquid or gas in the air pump flows through the air path into the airbag to expand the airbag and expand the peritubal space of the eustachian tube, so that hydroxyapatite can be effectively injected into the peritubal space, and the inner tube is limited by the limiting component, and then hydroxyapatite is quantitatively injected through the quantitative component.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a cannula structure for quantitatively injecting materials into the peritubal space of the eustachian tube. Background Art

[0002] The eustachian tube, also known as the auditory tube, connects the tympanic cavity and the nasopharynx, enabling the air in the tympanic cavity to communicate with the atmosphere. Thus, through the eustachian tube, the possible pressure difference between the air in the tympanic cavity and the atmospheric pressure can be balanced, which is of great significance for maintaining the normal position, shape, and vibration performance of the tympanic membrane. The pharyngeal orifice of the eustachian tube is normally in a closed state and only opens momentarily during swallowing, yawning, opening the mouth wide, and blowing the nose, etc., for gas exchange in the tympanic cavity. When the eustachian tube is blocked, the gas in the tympanic cavity will be absorbed, causing the pressure in the tympanic cavity to drop and resulting in tympanic membrane retraction. A temporary pressure difference between the inside and outside of the tympanic membrane often occurs when the pressure in the external auditory canal changes first while the pressure in the tympanic cavity remains in its original state, such as during the sudden ascent or descent of an airplane or long-term diving. At this time, if the pressure in the tympanic cavity cannot be balanced with the external auditory canal pressure (or atmospheric pressure) through the eustachian tube, a huge pressure difference will appear on both sides of the tympanic membrane. When the pressure difference exceeds 24 kPa (180 mmHg), the tympanic membrane may rupture.

[0003] If the muscles at the pharyngeal orifice are paralyzed or atrophied, the pharyngeal orifice may often be in an open state and cause symptoms, which is called patulous eustachian tube. Mental factors may also have an impact on the abnormal opening of the eustachian tube. Being in a state of long-term mental tension will cause the muscles to be in a state of tonic contraction, forcing the eustachian tube to open. Due to the mucosal edema of the eustachian tube caused by nasopharyngeal inflammation, etc., the abnormal opening of the eustachian tube occurs, and the soft tissues around the pharyngeal orifice are damaged, such as scar adhesion, or symptoms such as myasthenia gravis, etc., which may all cause eustachian tube abnormalities.

[0004] Currently, it mainly relies on medical staff for manual operation and drug injection treatment based on the clinical experience of medical staff, which is prone to errors and the accuracy cannot be guaranteed. Summary of the Invention

[0005] In order to solve the technical problems raised in the above background, the present invention provides a cannula structure for quantitatively injecting materials into the peritubal space of the eustachian tube. The peritubal cavity of the eustachian tube is expanded by an airbag assembly, so as to ensure that hydroxyapatite can be completely injected into the submucosa of the pharyngeal orifice tube, avoid injecting drugs into non-target lesion areas, and achieve quantitative injection for different patients or causes.

[0006] Based on the above technical idea, the technical solution adopted by the present invention is as follows:

[0007] An object of the present invention is to provide a cannula structure for quantitatively injecting materials into the peritubal space. The cannula structure includes an outer tube and an inner tube. The injection part of the inner tube is placed in the guiding cavity of the outer tube, and the medicine receiving part of the inner tube is placed in the movable cavity of the outer tube. The cannula structure further includes a push rod, which is placed in the movable cavity of the outer tube and contacts the proximal end surface of the medicine receiving part. An airbag assembly is arranged at the injection part of the inner tube. When the distal end of the inner tube moves to the outside of the outer tube, the airbag assembly acts to expand the injection area around the pharyngeal orifice.

[0008] On the basis of the above technical solution, further, the airbag assembly includes an airbag and an air pump. The airbag is sealed on the outer surface of the injection part of the inner tube and is communicated with the air pump through a passage on the side wall of the inner tube. A plurality of groups of resistance members are also arranged on the side wall of the inner tube. Each group of resistance members contacts the piston of the air pump. When the airbag moves to the outside of the outer tube along with the inner tube, the resistance members squeeze the piston to flow the gas / liquid in the air pump into the airbag, realizing the inflation of the airbag.

[0009] On the basis of the above technical solution, furthermore, the resistance member includes a movable rod A and a movable rod B. One end of the movable rod A is hinged to the outer wall of the inner tube, and the other end thereof is hinged to one end of the movable rod B. The other end of the movable rod B contacts the piston. The opposite surfaces of the movable rod A and the movable rod B are connected by a return spring A.

[0010] On the basis of the above technical solution, furthermore, the resistance member further includes a squeezing arc plate, which is fixed on the inner end surface of the distal end of the outer tube. When the movable rod A moves to the squeezing arc plate along with the inner tube, the squeezing arc plate squeezes the movable rod A to drive the movable rod B to squeeze the piston.

[0011] On the basis of the above technical solution, furthermore, a return spring B is arranged in the inner cavity of the air pump. In the initial state of the air pump, the piston is squeezed by the return spring B to the distal end of the air pump.

[0012] On the basis of the above technical solution, furthermore, the distal end of the injection part of the inner tube is bent to form a curved injection port, and the curved injection port is located outside the outer tube.

[0013] On the basis of the above technical solution, furthermore, the quantitative assembly includes a scale disk, which is connected to the outer wall of the outer tube through a fixing column. The inner channel of the fixing column is communicated with the movable cavity of the outer tube. A gear is arranged in the movable cavity, and the gear meshes with the tooth groove on the push rod. A connecting rod is arranged in the inner channel of the fixing column. One end of the connecting rod is connected to the gear, and the other end thereof is connected to the pointer on the scale disk.

[0014] On the basis of the above technical solution, further, a limiting component is also provided on the outer tube. The "Z"-shaped rod is hinged on the outer wall of the outer tube. A compression spring A is arranged between the upper horizontal section of the "Z"-shaped rod and the outer surface of the outer tube. A limiting post is arranged on the lower horizontal section of the "Z"-shaped rod. A moving hole is arranged on the outer surface of the outer tube. The limiting post is located in the moving hole, and the moving hole communicates with the moving cavity of the outer tube.

[0015] On the basis of the above technical solution, further, a convex block is arranged on the outer wall of the medicine-containing part of the inner tube. The convex block is located in the moving hole and can move along the moving hole. A limiting groove is arranged on the convex block. When the airbag moves to the outside of the outer tube, the limiting post is placed in the limiting groove.

[0016] Another object of the present invention is to provide an operation method for a casing structure for quantitatively injecting materials into the peritubal space of the eustachian tube. The operation method includes the following steps:

[0017] Step 1: Expand the eustachian tube with the airbag

[0018] Place the distal end of the casing structure through the nasal cavity to the nasopharynx, and then place it into the tissue space around the eustachian tube in front of the pharyngeal orifice of the eustachian tube in the nasopharynx. Push the inner tube distally by pressing the push rod, and the airbag moves to the outside of the outer tube. During the movement, the extrusion arc plate is triggered to squeeze the movable rod A, and the movable rod B is pulled to squeeze the piston to move in the air pump. The liquid or gas in the air pump flows through the air path into the airbag. After the airbag expands, it expands the peritubal space of the eustachian tube. At this time, the convex block moves to the distal end of the moving block.

[0019] Step 2: Press and release the "Z"-shaped rod to make the limiting post fall into the limiting groove, and the inner tube stops moving. Record the position pointed to by the pointer on the dial at this time, denoted as the initial value.

[0020] Step 3: Start quantitative injection of hydroxyapatite

[0021] Continue to push the push rod. The soft plug at the distal end of the push rod slides into the inner tube and passes the hydroxyapatite in the inner tube through the curved injection port to the submucosal space after balloon dilation, and injects hydroxyapatite into the peritubal space of the pharyngeal orifice of the eustachian tube to control and narrow the opening degree of the pharyngeal orifice of the eustachian tube. Stop continuous drug administration to achieve quantitative drug administration.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention adds an airbag assembly to the injection part of the inner tube. The airbag assembly consists of an airbag, an air pump, a movable rod A, a movable rod B, and a pressing arc plate. By moving the inner tube forward, the airbag is moved to the outside of the outer tube, and the pressing arc plate is triggered to press the movable rod A. The movable rod A then pulls the movable rod B to press the piston to move inside the air pump, and the liquid or gas in the air pump flows through the air path into the airbag to expand the submucosal space around the eustachian tube, so that hydroxyapatite can be effectively injected into the dense submucosal space around the eustachian tube, thereby increasing the lower volume of the submucosal space around the eustachian tube and narrowing and controlling the opening degree of the pharyngeal orifice of the eustachian tube.

[0024] 2. The present invention also provides a metering assembly on the outer tube. The metering assembly consists of a scale disk, a fixed column, a gear, a connecting rod, and a pointer. The pointer is combined with the gear through the connecting rod, and the gear is placed in the movable cavity of the outer tube and meshed with the tooth groove on the push rod. When the push rod moves forward, the gear rotates to drive the pointer to rotate, and the amount of hydroxyapatite injection is quantified by the interval of the pointer's movement on the scale disk.

[0025] 3. The present invention separates the operation of expanding the eustachian tube by the airbag and injecting medicine into the tympanic cavity through the limit assembly designed on the outer tube. The limit assembly consists of a "Z" - shaped rod, a compression spring A, a limit post, and a convex block. In the initial state, the soft plug of the push rod is located outside the inner tube and closely fits with the proximal end face of the inner tube. When starting to push the push rod, it squeezes the inner tube to move distally together. When the convex block on the inner tube moves along the moving hole to the farthest end of the moving hole, about 3 / 4 of the area of the airbag is squeezed to the outside of the outer tube and expands to enlarge the eustachian tube. Press and release the "Z" - shaped rod, and the limit post falls into the limit groove, and the inner tube stops moving forward. Then it enters the medicine injection stage. The limit assembly is used to realize the sequential operation of first opening the airbag and then injecting medicine. Brief Description of the Drawings

[0026] Figure 1 It is a schematic diagram of the initial state of a casing structure for quantitatively injecting materials into the submucosal space around the eustachian tube in the present invention.

[0027] Figure 2 It is another schematic diagram of the initial state of a casing structure for quantitatively injecting materials into the submucosal space around the eustachian tube in the present invention.

[0028] Figure 3 It is a schematic diagram of the outer tube in the present invention.

[0029] Figure 4 It is an axial sectional view of a casing structure for quantitatively injecting materials into the submucosal space around the eustachian tube in the present invention.

[0030] Figure 5 It is Figure 4 The enlarged view of part A in

[0031] Figure 6 It is a schematic diagram of the air pump in the present invention.

[0032] Figure 7 It is a schematic diagram of the limiting component in the present invention.

[0033] Figure 8 This is a schematic diagram of a sleeve structure airbag inflated for quantitatively injecting material into the space around the Eustachian tube in the present invention.

[0034] Figure 9 This is another schematic diagram of the inflated balloon of a sleeve structure for quantitatively injecting material into the space around the Eustachian tube in the present invention.

[0035] Figure 10 This is a cross-sectional view of a sleeve structure airbag inflated for quantitatively injecting material into the space around the Eustachian tube in the present invention.

[0036] Among them, 1. outer tube; 101. movable cavity; 102. movable hole; 103. guide cavity; 2. inner tube; 201. curved injection port; 202. medicine receiving part; 3. push rod; 301. tooth groove; 4. airbag assembly; 401. airbag; 402. extrusion arc plate; 403. movable rod A; 404. movable rod B; 405. piston; 406. reset spring B; 407. air pump; 408. reset spring A; 409. air path; 5. limit assembly; 501. "Z" type rod; 502. limit column; 503. compression spring A; 6. dial; 7. pointer; 8. fixed column; 9. gear; 10. soft plug; 11. compression spring B. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally. Example 1

[0038] This embodiment specifically provides a sleeve structure for quantitatively injecting materials into the space around the Eustachian tube, such as Figures 1-10 As shown, the sleeve structure includes an outer tube 1 and an inner tube 2 , the injection portion of the inner tube 2 is placed in the guide cavity 103 of the outer tube 1 , and the drug receiving portion 202 of the inner tube 2 is placed in the active cavity 101 of the outer tube 1 .

[0039] The sleeve structure also includes a push rod 3, which is placed in the active cavity 101 of the outer tube 1 and contacts the proximal surface of the medicine receiving part 202, and an airbag assembly 4 is provided at the injection part of the inner tube 2. When the distal end of the inner tube 2 moves to the outside of the outer tube 1, the airbag assembly 4 acts to open the pharyngeal injection area.

[0040] The airbag assembly 4 includes an airbag 401 and an air pump 407. The airbag 401 is sealed on the outer surface of the injection part of the inner tube 2 and is communicated with the air pump 407 through a passage on the side wall of the inner tube 2. A plurality of groups of resistance members are also arranged on the side wall of the inner tube 2, and each group of resistance members contacts the piston 405 of the air pump 407. When the airbag 401 moves to the outside of the outer tube 1 along with the inner tube 2, the resistance members squeeze the piston 405 to cause the gas / liquid in the air pump 407 to flow into the airbag 401, realizing the inflation of the airbag 401.

[0041] A return spring B406 is arranged in the inner cavity of the air pump 407. In the initial state, the return spring B406 fills the entire inner cavity of the air pump 407, squeezing the piston 405 to the farthest end of the air pump 407. At this time, the airbag 401 shrinks and adheres to the outer surface of the inner tube 2, and the injection part of the inner tube 2 and the airbag 401 are retracted into the guiding cavity 103 of the outer tube 1.

[0042] The resistance member includes a movable rod A403 and a movable rod B404. One end of the movable rod A403 is hinged to the outer wall of the inner tube 2, and the other end thereof is hinged to one end of the movable rod B404. The other end of the movable rod B404 contacts the piston 405. The opposite surfaces of the movable rod A403 and the movable rod B404 are connected by a return spring A408. In the initial state, the included angle between the movable rod B404 and the movable rod A403 is greater than 30 degrees.

[0043] In this embodiment, in order to prevent the circumferential inclination of the movable rod A403 and the movable rod B404, a groove is provided on the outer wall of the inner tube 2. The free end of the movable rod B404 is located in the groove and can move along the groove, and the side wall of the movable rod B404 contacts the piston 405.

[0044] The resistance member further includes a pressing arc plate 402. The pressing arc plate 402 is fixed on the inner end surface of the distal end of the outer tube 1. When the movable rod A403 moves to the pressing arc plate 402 along with the inner tube 2, the pressing arc plate 402 presses the movable rod A403 to drive the side wall of the movable rod B404 to press the piston 405, and the piston 405 moves proximally inside the air pump 407. The gas or liquid in the air pump 407 flows to the airbag 401 through the air path 409, and the airbag 401 is inflated. After the airbag 401 is inflated, hydroxyapatite is injected into the damaged area. After the injection is completed, the push rod 3 is pulled back to drive the inner tube 2 to move along the inner channel of the outer tube 1, and the airbag 401 is then passively squeezed and recovered. The liquid or gas in the airbag 401 is squeezed and flows back into the air pump 407, and the return spring B406 is reset, thereby squeezing the piston 405 to move distally in the air pump 407. At the same time, the movable rod B404 and the movable rod A403 are squeezed and reset, and the injection part of the inner tube 2 and the airbag 401 are retracted back into the guiding cavity 103 of the outer tube 1.

[0045] To ensure that the airbag 401 can be easily recovered, when the injection part of the inner tube 2 moves outward to the outside of the outer tube 1, the airbag 401 does not completely move to the outside of the outer tube 1. Part of the airbag 401 is squeezed between the inner wall of the outer tube 1 and the outer wall of the inner tube 2, that is, at the distal port of the outer tube 1.

[0046] In addition, a bent injection port 201 is formed at the distal end of the injection part of the inner tube 2, so as to concentrate the injection of hydroxyapatite in one area to avoid the situation that hydroxyapatite sprays around during linear injection. Embodiment 2

[0047] On the basis of Embodiment 1, a quantitative component is arranged on the outer tube 1 in this embodiment. The quantitative component includes a scale disk 6. The scale disk 6 is connected to the outer wall of the outer tube 1 through a fixing column 8. The inner channel of the fixing column 8 is communicated with the movable cavity 101 of the outer tube 1. A gear 9 is arranged in the movable cavity 101. The gear 9 meshes with the tooth groove 301 on the push rod 3. A connecting rod is arranged in the inner channel of the fixing column 8. One end of the connecting rod is connected to the gear 9, and the other end is connected to the pointer 7 on the scale disk 6.

[0048] When the push rod 3 moves forward, it meshes with the gear 9 to rotate. The rotation of the gear 9 drives the pointer 7 to rotate. Record the position pointed by the pointer 7 in the initial state, and then record the position pointed by the pointer 7 after the push rod 3 moves. Calculate the difference between the two positions pointed by the pointer 7 to obtain the injection amount of hydroxyapatite. This operation is not only easy to implement, but also can accurately record the injection amount of hydroxyapatite, so that accurate quantitative injection of hydroxyapatite can be realized without relying on the clinical experience of medical staff. Embodiment 3

[0049] The purpose of this embodiment is to separate the inflation of the airbag 401 from the injection of hydroxyapatite, and avoid the situation of injecting hydroxyapatite while the inner tube 2 moves to inflate the airbag 401. A limiting component 5 is also arranged on the outer tube 1. The limiting component 5 includes a "Z"-shaped rod 501. The "Z"-shaped rod 501 is hinged on the outer wall of the outer tube 1. A compression spring A503 is arranged between the upper horizontal section of the "Z"-shaped rod 501 and the outer surface of the outer tube 1. A limiting column 502 is arranged on the lower horizontal section of the "Z"-shaped rod 501. A moving hole 102 is arranged on the outer surface of the outer tube 1. The limiting column 502 is located in the moving hole 102. The moving hole 102 is communicated with the movable cavity 101 of the outer tube 1.

[0050] A convex block is arranged on the outer wall of the medicine receiving part 202 of the inner tube 2. The convex block is located in the moving hole 102 and can move along the moving hole 102. A limiting groove is arranged on the convex block. In the initial state, the convex block is located at the proximal end of the moving hole 102. When the airbag 401 moves to the outside of the outer tube 1, the limiting column 502 is placed in the limiting groove.

[0051] A compression spring B11 is also arranged in the movable cavity 101 of the outer tube 1. The compression spring B11 is sleeved on the outer wall of the inner tube 2 and is located between the distal end face of the medicine receiving part 202 and the distal end face of the movable cavity 101. A soft plug 10 is arranged at the distal end of the push rod 3. Under the action of the compression spring B11, the proximal port of the inner tube 2 is in close fit with the soft plug 10, and the proximal port of the inner tube 2 is sealed by the soft plug 10.

[0052] When the sleeve structure is produced, the injection part and the medicine receiving part 202 of the inner tube 2 are filled with hydroxyapatite, and then sealed with a sealing bag.

[0053] The specific operation methods of Embodiments 1-3 are as follows:

[0054] Insert the distal end of the sleeve structure through the nasal cavity to the nasopharynx, and then insert it into the submucosa around the eustachian tube through the front of the pharyngeal orifice of the eustachian tube in the nasopharynx. By pressing the push rod 3, the inner tube 2 is pushed to move distally, and the airbag 401 moves to the outside of the outer tube 1. During the movement, the extrusion arc plate 402 is triggered to squeeze the movable rod A403, and the movable rod B404 is pulled to squeeze the piston 405 to move in the air pump 407. The liquid or gas in the air pump 407 flows through the air path 409 into the airbag 401. After the airbag 401 expands, the submucosal space of the eustachian tube is expanded. At this time, press and release the "Z"-shaped rod 501 so that the limit post 502 falls into the limit groove, and the inner tube 2 stops moving. Record the position pointed to by the pointer 7 on the dial 6 at this time, which is recorded as the initial value; then continue to press the push rod 3, and the soft plug 10 at the distal end of the push rod 3 slides along the proximal port of the inner tube 2 into the inner cavity of the inner tube 2, and pushes the hydroxyapatite in the inner tube 2 to reach the submucosal space expanded by the balloon through the bent injection port 201, and injects hydroxyapatite into the peritubular space of the pharyngeal orifice of the eustachian tube to treat related diseases caused by eustachian tube failure. By observing the movement direction of the pointer 7 on the dial 6, if the specified position is reached, stop continuing to administer the medicine, so as to achieve quantitative administration.

[0055] The above content is a further detailed description of the present invention in combination with specific preferred implementation schemes, which is convenient for those skilled in the art of this technology to understand and apply the present invention. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, several simple deductions or replacements can be made without departing from the concept of the present invention, without the need for creative labor. Therefore, the simple improvements made by those skilled in the art according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A cannula structure for quantitatively injecting materials into the peritubal space. The cannula structure includes an outer tube and an inner tube. The injection part of the inner tube is placed in the guiding cavity of the outer tube, and the medicine-containing part of the inner tube is placed in the movable cavity of the outer tube. It is characterized in that, The cannula structure further includes a push rod, which is placed in the movable cavity of the outer tube and contacts the proximal end surface of the medicine receiving part, and an airbag assembly is arranged in the injection part of the inner tube. When the distal end of the inner tube moves to the outside of the outer tube, the airbag assembly acts to expand the pharyngeal orifice injection area; The airbag assembly includes an airbag and an air pump. The airbag is sealed on the outer surface of the injection part of the inner tube and is communicated with the air pump through a passage on the side wall of the inner tube. A plurality of groups of resistance members are also arranged on the side wall of the inner tube, and each group of resistance members contacts the piston of the air pump. When the airbag moves to the outside of the outer tube along with the inner tube, the resistance members squeeze the piston to flow the gas / liquid in the air pump into the airbag, realizing the inflation of the airbag; The resistance member includes a movable rod A and a movable rod B. One end of the movable rod A is hinged to the outer wall of the inner tube, and the other end thereof is hinged to one end of the movable rod B. The other end of the movable rod B contacts the piston, and the opposite surfaces of the movable rod A and the movable rod B are connected by a return spring A; The resistance member further includes a pressing arc plate, which is fixed on the inner end surface of the distal end of the outer tube. When the movable rod A moves to the pressing arc plate along with the inner tube, the pressing arc plate presses the movable rod A to drive the movable rod B to press the piston; The specific operation of the airbag assembly to expand the pharyngeal orifice refraction area is as follows: When the movable rod A moves to the pressing arc plate along with the inner tube, the pressing arc plate presses the movable rod A to drive the side wall of the movable rod B to press the piston, and the piston moves proximally inside the air pump. The gas or liquid in the air pump flows into the airbag through the air path, and the airbag is enlarged.

2. The cannula structure for quantitatively injecting materials into the peritubal space according to claim 1, characterized in that, A return spring B is arranged in the inner cavity of the air pump. In the initial state of the air pump, the piston is pressed by the return spring B to the distal end of the air pump.

3. The cannula structure for quantitatively injecting materials into the peritubal space according to claim 1, characterized in that, The distal end of the injection part of the inner tube is bent to form a curved injection orifice, and the curved injection orifice is located outside the outer tube.

4. The cannula structure for quantitatively injecting materials into the peritubal space according to claim 1, wherein The metering assembly includes a scale disk, which is connected to the outer wall of the outer tube through a fixed column. The inner channel of the fixed column is communicated with the movable cavity of the outer tube. A gear is arranged in the movable cavity, and the gear meshes with the tooth groove on the push rod. A connecting rod is arranged in the inner channel of the fixed column. One end of the connecting rod is connected to the gear, and the other end thereof is connected to the pointer on the scale disk.

5. A cannula structure for quantitatively injecting materials into the peritubal space according to claim 4, characterized in that, A limiting assembly is also arranged on the outer tube. The "Z"-shaped rod is hinged on the outer wall of the outer tube. A compression spring A is arranged between the upper horizontal section of the "Z"-shaped rod and the outer surface of the outer tube. A limiting column is arranged on the lower horizontal section of the "Z"-shaped rod. A moving hole is arranged on the outer surface of the outer tube, and the limiting column is located in the moving hole. The moving hole is communicated with the movable cavity of the outer tube.

6. The cannula structure for quantitatively injecting materials into the peritubal space according to claim 5, characterized in that, A convex block is arranged on the outer wall of the medicine receiving part of the inner tube. The convex block is located in the moving hole and can move along the moving hole. A limiting groove is arranged on the convex block. When the airbag moves to the outside of the outer tube, the limiting column is placed in the limiting groove.

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