A subretinal injector

Abstract

This invention discloses a subretinal injector, belonging to the field of medical devices, comprising: an injection barrel including an outer barrel and an inner barrel, the inner barrel having a liquid outlet; an inner piston movably disposed within the inner barrel, capable of moving to an initial position 1 and an ending position 1, the inner piston at the ending position closing the liquid outlet; a transmission member rotatably disposed at the end of the inner barrel opposite to the liquid outlet, the transmission member being connected to and capable of driving the inner piston; and a cylindrical piston movably disposed within the outer barrel, capable of moving to an initial position 2 and an ending position 2, the transmission member being connected to and driven by the cylindrical piston. When the cylindrical piston is at the initial position 2, the inner piston is at the initial position 1; the cylindrical piston moving to the ending position 2 drives the inner piston to the ending position 1 via the transmission member. Through the above configuration, this invention can significantly improve the accuracy of subretinal injection.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a subretinal injector. Background Technology

[0002] Extensive subretinal hemorrhage is a serious complication of age-related macular degeneration with a poor prognosis; polyposis choroidal vascular disease is a blinding eye disease with a relatively high incidence in my country, and the incidence rate is showing an increasing trend year by year. Both conditions often cause serious damage to the patient's eyes. Clinically, subretinal injection of tissue plasminogen activator is often used to treat subretinal hemorrhage and polyposis choroidal vascular disease caused by macular degeneration. When using a conventional syringe, the injection speed is directly affected by the pressure applied to the piston by the doctor, and the injection accuracy cannot be guaranteed.

[0003] Therefore, an eye drop application aid device that can be operated with one hand and is easy for elderly patients to use is designed, specifically a subretinal injector. Summary of the Invention

[0004] To overcome the problems mentioned in the background art, the present invention adopts the following technical solution:

[0005] A subretinal injector includes: an injection barrel comprising an outer barrel and an inner barrel, the inner barrel having a liquid outlet; an inner piston movably disposed within the inner barrel and movable to an initial position 1 and an ending position 1, wherein the inner piston at the ending position can close the liquid outlet, and the outer wall of the inner piston has an external threaded groove; a transmission member rotatably disposed at the end of the inner barrel opposite to the liquid outlet, the inner wall of the transmission member having a protrusion 1 and the outer wall of the transmission member having a protrusion 2, the protrusion 1 being slidably connected to the external threaded groove; and a cylinder piston movably disposed within the outer barrel and movable to an initial position 2 and an ending position 2, the inner wall of the cylinder piston having an internal threaded groove, the protrusion 2 being slidably connected to the internal threaded groove, wherein when the cylinder piston is at the initial position 2, the inner piston is at the initial position 1, and the cylinder piston moving to the ending position 2 drives the inner piston to the ending position 1 via the transmission member.

[0006] Furthermore, when the cylindrical piston is in the initial position two, the inner piston is in the initial position one; when the cylindrical piston is in the termination position two, the inner piston is in the termination position one. The proportion of the cylindrical piston displacement in the maximum stroke of the cylindrical piston is always equal to the proportion of the inner piston displacement in the maximum stroke of the inner piston. In use, the inner piston is driven by the cylindrical piston through the transmission component and reciprocates in the inner cylinder, thereby pushing the drug to be injected out through the liquid outlet or drawing it in through the liquid outlet.

[0007] Furthermore, there is a gap between the outer wall of the piston and the inner wall of the outer cylinder. When the piston moves from the initial position two to the termination position two, it can squeeze the fluid in the outer cylinder through the gap into the injection cylinder. If the outer wall of the piston is in contact with the inner wall of the outer cylinder, the air pressure in the inner cylinder will prevent the piston from moving to the termination position two.

[0008] Furthermore, the cross-sectional profile of the outer wall of the piston along the direction of movement is not circular; along the direction of movement of the piston, the cross-sectional profile of the inner wall of the outer cylinder is the same as that of the outer wall of the piston, so that the piston can only reciprocate within the outer cylinder and cannot rotate relative to the inner cylinder. This ensures that when the syringe is in use, only the transmission component rotates relative to the inner cylinder, preventing the inner piston or piston from rotating relative to the syringe barrel during linear motion and affecting injection accuracy.

[0009] Furthermore, the cross-section of the transmission component along the central axis of the inner cylinder is a centrally symmetrical figure, specifically a circle or a regular polygon. There is at least one protrusion of type one and at least one protrusion of type two.

[0010] Furthermore, the inner wall of the cylinder piston has a circular cross-sectional profile with protrusions along the moving direction, the protrusions being the cross-sectional shape of an internal thread groove, and the inner piston has a circular cross-sectional profile with notches along the moving direction, the notches being the cross-sectional shape of an external thread groove.

[0011] Furthermore, the end of the transmission component facing the liquid outlet is provided with a sliding groove, and the end of the inner cylinder away from the liquid outlet is provided with a sliding rail. The sliding groove is connected to the sliding rail, so that the transmission component can rotate relative to the inner cylinder, thereby achieving a transmission effect between the cylinder piston and the inner piston.

[0012] Furthermore, the outer wall of the syringe is provided with scale markings along the movement direction of the syringe piston. The end of the syringe piston at the initial position two facing the liquid outlet is aligned with one end of the scale markings, and the end of the syringe piston at the termination position two facing the liquid outlet is aligned with the other end of the scale markings, so that the syringe piston with the scale markings has the maximum stroke between the initial position two and the termination position two.

[0013] Furthermore, the smallest unit of the scale marking is no greater than 0.1 ml, the scale marking corresponds to the volume of the inner cylinder, and the outer cylinder is made of transparent material, so that the user can always observe the real-time position of the piston facing the outlet in the outer cylinder through the outer cylinder.

[0014] Furthermore, along the same direction, the internal thread groove and the external thread groove have the same rotation direction, so that the internal piston and the cylindrical piston on both sides of the transmission member move in the same direction.

[0015] Furthermore, along the movement direction of the cylinder piston, the distance between the initial position one and the termination position one is a, the distance between the initial position two and the termination position two is b, and the ratio of the pitch of the external thread groove to the pitch of the internal thread groove is at least a / b, so as to ensure that the internal piston can reach the termination position one when the cylinder piston reaches the termination position two.

[0016] Furthermore, the pitch of the external thread groove is greater than the pitch of the internal thread groove, so that the displacement of the inner piston is always less than the displacement of the cylinder piston, thereby reducing the difficulty for the user to control the injection accuracy.

[0017] Furthermore, the capacity of the inner cylinder is not less than 1 ml, and the capacity of the outer cylinder is not less than 10 ml.

[0018] Furthermore, an elastomer is provided at one end of the inner piston facing the liquid outlet, and an injection space is formed between the elastomer and the liquid outlet to prevent the drug to be injected from passing through the injection space during injection.

[0019] Furthermore, the outer wall of the elastomer presses against the inner wall of the inner cylinder, and the outer wall of the inner piston does not contact the inner wall of the inner cylinder.

[0020] Furthermore, along the moving direction of the inner piston, the cross-sectional profile of the outer wall of the elastic body is not circular, and the cross-sectional profile of the outer wall of the elastic body is the same as the cross-sectional profile of the inner wall of the inner cylinder, so that the inner piston cannot rotate relative to the inner cylinder when it moves in the inner cylinder.

[0021] The beneficial effects of this invention are:

[0022] 1. By setting up a cylindrical piston with an internal thread groove, an inner piston with an external thread groove, and a transmission component with protrusion one and protrusion two, with protrusion one slidably connected to the external thread groove and protrusion two slidably connected to the internal thread groove, the cylindrical piston can drive the transmission component to rotate through the internal thread groove when it reciprocates in the outer cylinder. The rotating transmission component further drives the inner piston to reciprocate in the inner cylinder. The pitch of the external thread groove is greater than the pitch of the internal thread groove, so that the displacement of the cylindrical piston is greater than the displacement of the inner piston during injection. This can reduce the impact of the user's pressure on the cylindrical piston on the injection speed, thereby improving the user's control over the injection accuracy. This syringe has excellent injection accuracy control effect.

[0023] 2. By setting a transparent outer cylinder and setting a scale mark representing the volume of the inner cylinder between the initial position two and the end position two, a scale magnification effect is achieved, allowing users to more clearly and intuitively understand the remaining amount of injectable material in the inner cylinder when performing injection. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention when the piston is in the initial position two in Example 1;

[0026] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure;

[0027] Figure 3 This is a schematic diagram of the overall structure of the present invention when the piston is in the initial position in Example 1;

[0028] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure;

[0029] Figure 5 This is a cross-sectional structural diagram of the injection cartridge in Example 1;

[0030] Figure 6 This is a schematic diagram of the overall structure of the transmission component in Example 1;

[0031] Figure 7 for Figure 6 A schematic diagram of the cross-sectional structure;

[0032] Figure 8 This is a schematic cross-sectional view of the piston in Example 1;

[0033] Figure 9 This is a schematic diagram of the overall structure of the piston in Example 1;

[0034] Figure 10 This is a schematic diagram of the overall structure of Example 2;

[0035] In the diagram, 1. Injector; 11. Outer cylinder; 111. Scale markings; 12. Inner cylinder; 121. Dispensing port; 122. Injection space; 123. Slide rail; 2. Inner piston; 21. Initial position one; 22. Ending position one; 23. External thread groove; 24. Elastomer; 3. Transmission component; 31. Protrusion one; 32. Protrusion two; 33. Slide groove; 4. Cylinder piston; 41. Initial position two; 42. Ending position two; 43. Internal thread groove; 5. Pedal; 51. Vent pipe; 52. Compression chamber. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention are clearly and completely described below through specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] A subretinal injector, such as Figure 1-9 As shown, it includes: a syringe 1, which includes an outer cylinder 11 and an inner cylinder 12, the inner cylinder 12 having a liquid outlet 121; an inner piston 2, movably disposed in the inner cylinder 12, and movable to an initial position 21 and a final position 22, the inner piston 2 in the final position being able to close the liquid outlet 121, the outer wall of the inner piston 2 having an external threaded groove 23; and a transmission member 3, rotatably disposed at one end of the inner cylinder 12 away from the liquid outlet 121, the inner wall of the transmission member 3 having a protrusion 31, and the outer wall of the transmission member 3 having a protrusion 31. The device includes a second protrusion 32 and a first protrusion 31 slidably connected to an external threaded groove 23; a cylindrical piston 4 is movably disposed inside an outer cylinder 11 and can move to an initial position 41 and a final position 42. The inner wall of the cylindrical piston 4 is provided with an internal threaded groove 43, and the second protrusion 32 is slidably connected to the internal threaded groove 43. When the cylindrical piston 4 is in the initial position 41, the inner piston 2 is in the initial position 21. When the cylindrical piston 4 moves to the final position 42, the inner piston 2 is driven to the final position 22 through the transmission member 3.

[0039] A more preferred embodiment is, for example, Figure 1-9 As shown, when the cylindrical piston 4 is in the initial position 41, the inner piston 2 is in the initial position 21; when the cylindrical piston 4 is in the termination position 42, the inner piston 2 is in the termination position 22. The proportion of the displacement of the cylindrical piston 4 in the maximum stroke of the cylindrical piston 4 is always equal to the proportion of the displacement of the inner piston 2 in the maximum stroke of the inner piston 2. In use, the inner piston 2 is driven by the cylindrical piston 4 through the transmission component 3 and reciprocates in the inner cylinder 12, thereby pushing out or drawing in the drug to be injected through the liquid outlet 121.

[0040] A more preferred embodiment is, for example, Figure 1-9As shown, there is a gap between the outer wall of the piston 4 and the inner wall of the outer cylinder 11. When the piston 4 moves from the initial position 41 to the termination position 42, it can squeeze the fluid in the outer cylinder 11 through the gap into the injection cylinder 1. If the outer wall of the piston 4 is in contact with the inner wall of the outer cylinder 11, the air pressure in the inner cylinder 12 will prevent the piston 4 from moving to the termination position 42.

[0041] In another preferred embodiment, the outer wall of the cylinder piston 4 is fitted with the inner wall of the outer cylinder 11, and an exhaust hole is provided on the side wall of the outer cylinder 11. When the cylinder piston 4 moves to the termination position 42, the gas in the outer cylinder 11 overflows through the exhaust hole, and the cylinder piston 4 is not subjected to air pressure resistance while moving stably.

[0042] A more preferred embodiment is, for example, Figure 1-9 As shown, the cross-sectional profile of the outer wall of the piston 4 along the moving direction is not circular; along the moving direction of the piston 4, the cross-sectional profile of the inner wall of the outer cylinder 11 is the same as that of the outer wall of the piston 4, so that the piston 4 can only reciprocate within the outer cylinder 11 and cannot rotate relative to the inner cylinder 12. This ensures that when the syringe is in use, only the transmission component 3 rotates relative to the inner cylinder 12, preventing the inner piston 2 or the piston 4 from rotating relative to the syringe 1 when making linear motion and affecting the injection accuracy.

[0043] Another preferred embodiment is that the outer wall of the cylinder piston 4 is provided with a protrusion along the moving direction, and the inner wall of the outer cylinder 11 is provided with a groove along the moving direction of the cylinder piston 4. The protrusion can reciprocate within the groove along the moving direction of the cylinder piston 4, and the movement trajectory of any point on the cylinder piston 4 is a line segment. This can also prevent the cylinder piston 4 from rotating relative to the outer cylinder 11 during reciprocating motion.

[0044] A more preferred embodiment is, for example, Figure 1-9 As shown, the cross-section of the transmission component 3 along the central axis of the inner cylinder 12 is a centrally symmetrical figure, specifically a circle or a regular polygon. There is at least one protrusion 31 and at least one protrusion 32. The more protrusions there are, the higher the structural stability of the transmission component 3 when it rotates. However, the greater the component force generated by the compression between the transmission component 3 and the internal thread groove 43 and the external thread groove 23 when it rotates, the more difficult it is for the user to push the cylinder piston 4. Therefore, the number of protrusions 31 and 32 should not exceed three each.

[0045] A more preferred embodiment is, for example, Figure 1-9 As shown, the cross-sectional profile of the inner wall of the cylinder piston 4 along the moving direction is a circle with a protrusion. The protrusion is the cross-sectional shape of the internal thread groove 43. The specific shape of the protrusion is one of semi-circle, rectangle or T-shape. The cross-sectional profile of the inner piston 2 along the moving direction is a circle with a notch. The notch is the cross-sectional shape of the external thread groove 23. The shape of the notch is the same as or different from the shape of the protrusion.

[0046] A more preferred embodiment is, for example, Figure 1-9 As shown, the end of the transmission component 3 facing the liquid outlet 121 is provided with a groove 33, and the end of the inner cylinder 12 away from the liquid outlet 121 is provided with a slide rail 123. The groove 33 is connected to the slide rail 123, so that the transmission component 3 can rotate relative to the inner cylinder 12, thereby achieving a transmission effect between the cylinder piston 4 and the inner piston 2. Alternatively, a bearing is provided between the transmission component 3 and the inner cylinder 12, and the transmission component 3 and the inner cylinder 12 are rotatably connected through the bearing.

[0047] A more preferred embodiment is, for example, Figure 1-9 As shown, the outer wall of the syringe 1 is provided with a scale mark 111 along the movement direction of the piston 4. The end of the piston 4 in the initial position 41 facing the outlet 121 is aligned with one end of the scale mark 111. Specifically, the end of the piston 4 in the initial position 41 facing the outlet 121 is aligned with the maximum scale value of the scale mark 111. The end of the piston 4 in the termination position 42 facing the outlet 121 is aligned with the other end of the scale mark 111. Specifically, the end of the piston 4 in the termination position 42 facing the outlet 121 is aligned with the zero scale value of the scale mark 111. This allows the piston 4 with the scale mark 111 to travel the maximum stroke between the initial position 41 and the termination position 42.

[0048] A more preferred embodiment is, for example, Figure 1-9 As shown, the smallest unit of the scale marking 111 is no greater than 0.1 ml, the capacity of the inner cylinder 12 is no less than 1 ml, and the capacity of the outer cylinder 11 is no less than 10 ml. The scale marking 111 corresponds to the volume of the inner cylinder 12, and the outer cylinder 11 is made of transparent material so that the user can always observe the real-time position of the piston 4 facing the outlet 121 inside the outer cylinder 11 through the outer cylinder 11. Thus, the remaining volume of the outer cylinder 11 can represent the remaining volume of the inner cylinder 12, and the remaining volume of the outer cylinder 11 can be visualized through the scale marking 111. Finally, the user can intuitively see the magnified injection progress.

[0049] A more preferred embodiment is, for example, Figure 1-9 As shown, the internal thread groove 43 and the external thread groove 23 have the same rotation direction along the same direction, making the internal piston 2 and the cylinder piston 4 on both sides of the transmission component 3 move in the same direction. Along the movement direction of the cylinder piston 4, the distance between the initial position 1 21 and the final position 1 22 is 'a', and the distance between the initial position 2 41 and the final position 2 42 is 'b'. The ratio of the pitch of the external thread groove 23 to the internal thread groove 43 is at least a / b, ensuring that the internal piston 2 can reach the final position 1 22 when the cylinder piston 4 reaches the final position 2 42. The pitch of the external thread groove 23 is greater than the pitch of the internal thread groove 43, so that the displacement of the internal piston 2 is always less than the displacement of the cylinder piston 4, thereby reducing the difficulty for the user to control the injection accuracy.

[0050] A more preferred embodiment is, for example, Figure 1-9 As shown, an elastic body 24 is provided at the end of the inner piston 2 facing the outlet 121. The elastic body 24 is made of rubber or silicone, and the end of the elastic body 24 facing the outlet 121 is tapered so that when the inner piston 2 reaches the termination position 22, the elastic body 24 can fit tightly against the outlet 121, allowing all the fluid in the inner cylinder 12 to be pushed out. A push space 122 is formed between the elastic body 24 and the outlet 121, preventing the drug to be injected from passing through the push space 122 during injection. The inner cylinder 12 is made of the same material as the outer cylinder 11.

[0051] A more preferred embodiment is, for example, Figure 1-9 As shown, the outer wall of the elastic body 24 presses against the inner wall of the inner cylinder 12, and the outer wall of the inner piston 2 does not contact the inner wall of the inner cylinder 12, thereby preventing [the inner piston from rotating relative to the inner cylinder 12]. Along the moving direction of the inner piston 2, the cross-sectional profile of the outer wall of the elastic body 24 is not circular, and the cross-sectional profile of the outer wall of the elastic body 24 is the same as the cross-sectional profile of the inner wall of the inner cylinder 12, so that the inner piston 2 cannot rotate relative to the inner cylinder 12 when it moves in the inner cylinder 12.

[0052] A more preferred embodiment is that the outer cylinder 11 is provided with a wing at the end opposite to the liquid outlet 121, so as to facilitate the user's grip.

[0053] In use, the end of the cylindrical piston 4 facing the outlet 121 is in the second termination position 42, and the end of the inner piston 2 facing the outlet 121 is in the first termination position 22. The user grasps the outer wall of the syringe 1 or presses the flaps on the outer cylinder 11, and simultaneously pulls the cylindrical piston 4 away from the outlet 121 to allow the liquid to be injected to enter the injection space 122 through the outlet 121. When the end of the cylindrical piston 4 facing the outlet 121 reaches the second termination position 41, the inner piston 2 is in the first termination position 22. When one end of the outlet 121 reaches the initial position 21, the injection space 122 is filled with the medicine. A needle is attached to the front end of the outlet 121 and placed in the injection position. The user then holds the outer wall of the syringe 1 or tightens the flaps on the outer cylinder 11 while pressing the piston 4 toward the end facing the outlet 121 and observing the scale mark 111 that the piston 4 passes toward the outlet 121. Pressing the piston 4 stops when the injection is completed or the injection volume reaches the target value.

Claims

1. A subretinal injector, characterized in that, include: A syringe, comprising an outer cylinder and an inner cylinder, wherein the inner cylinder is provided with a liquid outlet; An inner piston is movably disposed in the inner cylinder and can move to an initial position and an ending position. The inner piston at the ending position can close the liquid outlet. The outer wall of the inner piston is provided with an external threaded groove. A transmission component is rotatably disposed at one end of the inner cylinder away from the liquid outlet. The inner wall of the transmission component is provided with a first protrusion, and the outer wall of the transmission component is provided with a second protrusion. The first protrusion is slidably connected to the external thread groove. A cylindrical piston is movably disposed inside the outer cylinder and can move to an initial position two and an ending position two. The inner wall of the cylindrical piston is provided with an internal thread groove, and the second protrusion is slidably connected to the internal thread groove. When the cylindrical piston is in the initial position two, the inner piston is in the initial position one. When the cylindrical piston moves to the ending position two, the inner piston is driven to the ending position one through the transmission component. The outer wall of the injection cylinder is marked with graduations along the direction of piston movement.

2. A subretinal injector according to claim 1, characterized in that, There is a gap between the outer wall of the piston and the inner wall of the outer cylinder. When the piston moves from the initial position two to the final position two, the fluid in the outer cylinder can be squeezed out of the injection cylinder through the gap.

3. A subretinal injector according to claim 2, characterized in that, The cross-sectional profile of the outer wall of the cylinder piston along the direction of movement is not circular; along the direction of movement of the cylinder piston, the cross-sectional profile of the inner wall of the outer cylinder is the same as that of the outer wall of the cylinder piston.

4. A subretinal injector according to claim 1, characterized in that, The end of the piston in initial position two facing the liquid outlet is aligned with one end of the scale mark, and the end of the piston in initial position one facing the liquid outlet is aligned with the other end of the scale mark.

5. A subretinal injector according to claim 4, characterized in that, The scale markings correspond to the volume of the inner cylinder, and the outer cylinder is made of transparent material.

6. A subretinal injector according to claim 1, characterized in that, Along the same direction, the internal thread groove and the external thread groove have the same rotation direction.

7. A subretinal injector according to claim 1, characterized in that, Along the direction of movement of the cylinder piston, the distance between the first initial position and the first final position is a, the distance between the second initial position and the second final position is b, and the ratio of the pitch of the external thread groove to the pitch of the internal thread groove is at least a / b.

8. A subretinal injector according to claim 1, characterized in that, An elastic body is provided at one end of the inner piston facing the liquid outlet, and a pushing space is formed between the elastic body and the liquid outlet.

9. A subretinal injector according to claim 8, characterized in that, The outer wall of the elastomer presses against the inner wall of the inner cylinder, while the outer wall of the inner piston does not contact the inner wall of the inner cylinder.

10. A subretinal injector according to claim 9, characterized in that, Along the moving direction of the inner piston, the cross-sectional profile of the outer wall of the elastic body is not circular, and the cross-sectional profile of the outer wall of the elastic body is the same as the cross-sectional profile of the inner wall of the inner cylinder.

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