INJECTOR WITH A PISTON TIP FEATURING MULTIPLE ARMS

Description

[0001] The invention relates to an injector for inserting an intraocular lens into the capsular bag of an eye. US 2007 / 005135 A1 discloses a plunger for inserting an intraocular lens, wherein the plunger has a soft tip. FR 2 789 890 A1 discloses a syringe for implanting a soft intraocular lens with a one-piece shaft connected to a cylindrical tip by a conical section. EP 3 494 927 A1 discloses a male mold designed as a connecting element for an injector. During cataract treatment of an eye, conventionally only a small incision is made in the cornea of ​​the eye, which is large enough for the tip of an injector to be inserted through the incision into the eye. After the incision has been made in the cornea, the lens of the eye is comminuted, for example by phacoemulsification, and then suctioned out of the capsular bag of the eye.An intraocular lens is then inserted into the eye using the injector. The intraocular lens is folded in the injector so that it fits through the tip. The tip is inserted through the incision into the capsular bag, and the folded intraocular lens is pushed through the tip into the capsular bag using the injector's plunger, where the intraocular lens unfolds, replacing the original lens.

[0002] In order to make the incision in the cornea as small as possible, the tip of the injector must be as small as possible. This results in the intraocular lens and plunger being severely crushed when the plunger pushes the intraocular lens into the tip, which results in high mechanical stress on the intraocular lens and plunger and, in extreme cases, can damage the intraocular lens and / or plunger. The severe crushing of the intraocular lens and plunger also leads to high mechanical stress on the tip, and this high mechanical stress can lead to damage to the tip. For example, parts of the tip can be irreversibly deformed outwards, which in extreme cases can lead to the tip causing an extension of the incision and / or damage to the eye when the tip is pulled out of the eye.

[0003] The object of the invention is therefore to provide an injector for introducing an intraocular lens into the capsular bag of an eye, wherein a tip of the injector can be made small without the risk of damaging the tip.

[0004] The injector according to the invention for introducing an intraocular lens into the capsular bag of an eye has an injector tip that delimits an opening, and a piston that is mounted in the injector so as to be longitudinally displaceable along a longitudinal axis of the injector and has a piston tip that is made of a material with a hardness in a range of 20 to 80 Shore A and is configured to displace the intraocular lens out of the injector via the opening, wherein the piston tip has a central region and a plurality of arms that are attached to the central region and are arranged side by side in the circumferential direction with respect to the longitudinal axis, wherein the piston tip has a relaxed state in which the arms each have an inner region and an outer region that is arranged further away from the central region than the inner region and has a longer extension in the circumferential direction than the inner region.Because the piston tip is made of a material with a hardness in the range of 10 to 80 Shore A and has a plurality of arms, it can deform when it enters the injector tip. Because the inner region has a shorter circumferential extension than the outer region, the inner region deforms more quickly than the outer region. This allows the outer region to shift circumferentially and even towards the central region. This allows the piston tip to be squeezed tightly from its relaxed state without excessive mechanical stress occurring in the piston tip, which could lead to damage to the injector tip. This makes it possible to make the injector tip relatively small without there being any risk of damage to the injector tip.

[0005] It is preferred that the hardness is in a range of 20 to 80 Shore A and in particular 20 to 50 Shore A.

[0006] It is according to the invention that the piston tip has an end face which is arranged facing the opening and which, in the relaxed state, has a center point through which the longitudinal axis runs, wherein the arms in the relaxed state each have a first point which is the point furthest away from the longitudinal axis, wherein the piston tip has a partially prestressed state in which the arms are prestressed by a force which acts on the arms from the outside in the radial direction with respect to the longitudinal axis and are displaced in the direction of the longitudinal axis and in which the arms each have a second point which is the point furthest away from the longitudinal axis, wherein the second point is arranged closer to the longitudinal axis than the first point.The force acting on the arms from the outside in the radial direction is generated when the piston tip contacts a wall of the injector, in particular the wall of the injector tip. Because the end face is arranged facing the opening, the end face contacts the intraocular lens when the piston is displaced longitudinally towards the opening. The center point is the center of gravity of the end face and is arranged in the central region. It is particularly preferred that twice the distance of the first point to the longitudinal axis is longer than a maximum extension of the opening, wherein the maximum extension of the opening is determined by projecting the opening onto a plane whose normal is oriented parallel to the longitudinal axis, and the maximum extension of the opening is determined as a maximum extension of the opening projected onto the plane.As a result, the injector tip in the relaxed state has a longer diameter than the maximum extension of the opening.

[0007] The piston tip preferably has a fully preloaded state, which the piston tip assumes after the piston tip has passed through the partially preloaded state from the relaxed state, and in which one of the arms is abutted against the central region and / or against another arm arranged circumferentially adjacent to the one arm. It is also conceivable that in the fully preloaded state, a majority or all of the arms are abutted against the central region and / or against the respective adjacent arm.

[0008] It is preferred that the injector has an injector tip that forms the opening and defines an interior space that tapers toward the opening. This allows the injector tip to be gradually moved from the relaxed state, through the partially preloaded state, to the fully preloaded state.

[0009] The piston preferably has a piston shaft on which the piston tip is arranged and which is made of a material with a hardness of at least 20 Shore A. This advantageously ensures that only the piston tip of the piston is deformed. Thus, excessive shortening of the piston in the direction of the longitudinal axis can be prevented.

[0010] The piston can be manufactured, for example, using an injection molding process. In particular, the piston tip and piston skirt can be manufactured using two different injection steps. Such a process is known, for example, as a 2K injection molding process. The material of the piston tip can be different from that of the piston skirt.

[0011] The arms are preferably structurally identical. It is also preferred that, in the relaxed state, all the arms are arranged at equal distances from the adjacent arms in the circumferential direction. Preferably, three to five arms are provided.

[0012] It is preferred that, in the relaxed state, each of the arms has an outer line whose point, in each axial position, is that point of the respective arm which is furthest from the injector axis, wherein the distance of the outer line to the longitudinal axis becomes shorter with increasing distance from the opening, at least in one region along the longitudinal axis. As a result, the injector tip can be deformed more easily than in the case where the outer line has the same distance from the longitudinal axis along the entire injector tip. It is particularly preferred that the outer line has a minimum, which is the point of the outer line which has the shortest distance from the longitudinal axis, wherein the minimum has a shorter distance from the longitudinal axis than any point on the outside of the piston shaft at its longitudinal end facing the piston tip.The piston tip for each arm may have a reinforcing rib which is arranged in an axial region of the piston in which the minimum is also arranged and which supports two adjacent arms in the circumferential direction.

[0013] The arms preferably have no recesses inside. This makes them particularly easy to manufacture.

[0014] It is preferred that the arms be curved in the circumferential direction in the relaxed state. This allows the arms to be displaced particularly easily in the circumferential direction when a force acts on the arms from the outside in the radial direction relative to the longitudinal axis. Particularly preferably, all the arms are curved in the same direction.

[0015] The invention is explained in more detail below with reference to the attached schematic drawings. Figures 1 to 4a first embodiment of an injector tip at four different times, Figures 5 and 6 a second embodiment of the injector tip at two different times, Figure 7 a front view of a first embodiment of a piston, Figure 8 a side view from the front of the first embodiment according to Figure 7 and Figure 9 a side view of an injector with the first embodiment according to Figures 7 and 8 . Figure 10 a side view of a second embodiment of the piston.

[0016] How it turns out Figures 1 to 9As can be seen, an injector 10 for inserting an intraocular lens into the capsular bag of an eye has an injector tip 14 which delimits an opening 15, and a piston 1. The piston 1 is mounted in the injector 10 so as to be longitudinally displaceable along a longitudinal axis 11 of the injector 10 and has a piston tip 2 which is made of a material with a hardness in a range of 10 to 80 Shore A and is designed to displace the intraocular lens out of the injector 10 via the opening 15. The piston tip 2 has a central region 5 and a plurality of arms 7 which are fastened to the central region 5 and are arranged next to one another in the circumferential direction 13 with respect to the longitudinal axis 11.The piston tip 2 has a relaxed state in which the arms 7 each have an inner region 8 and an outer region 9 which is arranged further away from the central region 5 than the inner region 8 and has a longer extension in the circumferential direction 13 than the inner region 8.

[0017] Figures 1 to 9 also show that all the arms 7 can be structurally identical. Furthermore, in the relaxed state, all the arms 7 can be arranged spaced apart from one another in the circumferential direction 13 and, in particular, at equal distances from the adjacent arms 7. Figures 1 to 4 and 7 to 9 show that, for example, three of the arms 7 can be provided. Figures 5 and 6show that, for example, four arms can be provided. However, other numbers of arms 7 are also conceivable, such as five, six, or seven. Furthermore, it is conceivable that the arms 7 do not have any recesses in their interior.

[0018] Figures 1 , 5 and 7 to 9 show the piston tip 2 in the relaxed state. As can be seen from Figures 1 to 8 As can be seen, the piston tip 2 can have an end face 4 which is arranged facing the opening 15 and which, in the relaxed state, has a center point 6 through which the longitudinal axis 11 runs (cf. Figure 8 ), wherein the arms 7 in the relaxed state each have a first point 17, which is the point furthest from the longitudinal axis 11, wherein the piston tip 2 can have a partially prestressed state, which in Figures 2 and 3and in which the arms 7 are prestressed by a force acting in the radial direction 12 with respect to the longitudinal axis 11 from the outside on the arms 7 and are displaced in the direction of the longitudinal axis 11, and in which the arms 7 each have a second point 18, which is the point furthest away from the longitudinal axis 11, wherein the second point 18 in the partially prestressed state is arranged closer to the longitudinal axis 11 than the first point 17 in the relaxed state. The center point 6 can be the center of gravity of the end face 4 in the relaxed state. In Figure 3 the piston tip 2 is more strongly preloaded than in Figure 2 , whereby the second point 18 in Figure 3 closer to the longitudinal axis 11 than in Figure 2 It is located in Figures 2 and 3 It can be seen that the arms 7, particularly in the inner region 8, are in a more relaxed state compared to the relaxed state (see Figure 1) are deformed so that all the arms 7 are bent in the same circumferential direction 13.

[0019] Out of Figure 9 It can be seen that twice the distance of the first point 17 to the longitudinal axis 11 can be longer than a maximum extension of the opening 15, wherein the maximum extension of the opening 15 is determined by projecting the opening 15 onto a plane whose normal is oriented parallel to the longitudinal axis 11, and the maximum extension of the opening 15 is determined as a maximum extension of the opening 15 projected onto the plane.

[0020] Figure 4shows that the piston tip 2 can have a fully preloaded state, which the piston tip 2 assumes after the piston tip 2 has passed through the partially preloaded state from the relaxed state, and in which one of the arms 7 is abutted against another arm 7, which is arranged adjacent to the one arm 7 in the circumferential direction 13. Alternatively or additionally, it is conceivable that the one arm 7 is abutted against the central region 5 in the fully preloaded state. Furthermore, it is conceivable that all of the arms 7 are abutted against an adjacent arm 7 and / or the central region 5.

[0021] Figures 7 to 9 show that the piston 1 can have a piston shaft 3 on which the piston tip 2 is arranged and which is made of a material with a hardness of at least 20 Shore A. From Figure 9It is also apparent that the complete piston skirt 3 can be arranged in a region extending in the radial direction 12 with respect to the longitudinal axis 11, which is arranged less far away from the longitudinal axis 11 than the first point 17.

[0022] Out of Figures 9 and 10 It can be seen that in the relaxed state, each of the arms 7 can have an outer line 19, the point of which in each axial position is the point of the respective arm 7 which is furthest away from the injector axis 11, wherein the distance of the outer line 19 to the longitudinal axis 11 becomes shorter at least in a region along the longitudinal axis 11 with increasing distance from the opening 15. In addition, Figure 9 that the injector tip 14 can define an interior space 16 which tapers towards the opening 15.

[0023] Figure 10shows that the outer line 19 has a minimum 21, which is the point on the outer line 19 that has the shortest distance to the longitudinal axis 11, wherein the minimum 21 has a shorter distance to the longitudinal axis 11 than any point on the outside of the piston skirt 3 at its longitudinal end 20 facing the piston tip 2. The piston tip 3 can have a reinforcing rib 22 for each arm 7, which is arranged in an axial region of the piston 1 in which the minimum 21 is also arranged, and which supports two adjacent arms 7 in the circumferential direction 13.

[0024] Figures 7 and 8 show that the arms 7 can be curved in the circumferential direction 13 in the relaxed state. In particular, a center line 19, which is arranged on the end face 4 and runs in the middle of the arm 7 and along the entire length of the arm 7, can be curved. List of reference symbols

[0025] 1 Piston 2 Piston tip 3 Piston skirt 4 End face 5 Central area 6 Center point 7 Arm 8 Inner area 9 Outer area 10 Injector 11 Longitudinal axis 12 Radial direction 13 Circumferential direction 14 Injector tip 15 Opening 16 Interior 17 First point 18 Second point 19 Outline 20 Longitudinal end of the piston skirt 21 Minimum 22 Reinforcing rib

Claims

1. Injector for inserting an intraocular lens into the capsular bag of an eye, having an injector tip (14), which delimits an opening (15), and a plunger (1), which is mounted in the injector (10) in such a way as to be longitudinally displaceable along a longitudinal axis (11) of the injector (10) and has a plunger tip (2) which is made of a material with a hardness in a range of 10 to 80 Shore A and is configured to move the intraocular lens out of the injector (10) via the opening (15), characterized in that the plunger tip (2) has a central region (5) and a plurality of arms (7), which are attached to the central region (5) and are arranged next to one another in the circumferential direction (13) with respect to the longitudinal axis (11), wherein the plunger tip (2) has a relaxed state in which the arms (7) each have an inner region (8) and an outer region (9), the latter being arranged further than the inner region (8) from the central region (5) and having a longer extent than the inner region (8) in the circumferential direction (13), wherein the plunger tip (2) has a front face (4), which is arranged facing the opening (15) and which, in the relaxed state, has a centre point (6) through which the longitudinal axis (11) runs, wherein the arms (7), in the relaxed state, each have a first point (17), which is the point furthest from the longitudinal axis (11), wherein the plunger tip (2) has a partially pretensioned state in which the arms (7) are pretensioned by a force acting on the arms (7) from the outside in a radial direction (12) with respect to the longitudinal axis (11) and are moved towards the longitudinal axis (11), and in which the arms (7) each have a second point (18), which is the point furthest from the longitudinal axis (11), wherein the second point (18) is arranged closer to the longitudinal axis (11) than the first point (17).

2. Injector according to Claim 1, wherein twice the distance from the first point (17) to the longitudinal axis (11) is longer than a maximum extent of the opening (15), wherein the maximum extent of the opening (15) is defined by the opening (15) being projected onto a plane whose normal is oriented parallel to the longitudinal axis (11), and the maximum extent of the opening (15) is defined as a maximum extent of the opening (15) projected onto the plane.

3. Injector according to Claim 1 or 2, wherein the plunger tip (2) has a fully pretensioned state that the plunger tip (2) assumes after the plunger tip (2), starting from the relaxed state, has passed through the partially pretensioned state, and in which one of the arms (7) abuts the central region (5) and / or another arm (7), which is arranged adjacent to the one arm (7) in the circumferential direction (13).

4. Injector according to any one of Claims 1 to 3, wherein the injector tip (14) delimits an interior space (16), which tapers in the direction of the opening (15).

5. Injector according to any one of Claims 1 to 4, wherein the plunger (1) has a plunger shaft (3), on which the plunger tip (2) is arranged and which is made of a material with a hardness of at least 20 Shore A.

6. Injector according to any one of Claims 1 to 5, wherein the arms (7) are shaped identically.

7. Injector according to any one of Claims 1 to 6, wherein, in the relaxed state, each of the arms (7) has an outer line, the points of which in each axial position are the point of the respective arm (7) furthest from the injector axis (11), wherein the distance of the outer line from the longitudinal axis (11), at least in one region along the longitudinal axis (11), becomes shorter as the distance from the opening (15) increases.

8. Injector according to any one of Claims 1 to 7, wherein the arms (7) have no recesses in their interior.

9. Injector according to any one of Claims 1 to 8, wherein the arms (7) are curved in the circumferential direction (13) in the relaxed state.