INJECTOR FOR INTRAOCULAR LENSES

20230285139 · 2023-09-14

    Inventors

    Cpc classification

    International classification

    Abstract

    An intraocular lens implantation injector has a base body and an elongated actuation element projecting into a base body rear section and movably guided along an actuation axis. Actuation element movement is generated selectively by axial push actuation or by a screw actuation about the axis. The actuation element features an external thread at least on one section. At least one spring arm arranged at the base body has an inner surface thread engagement structure facing the external thread. A switch element, interacting with the spring arm, is rotatably or displaceably arranged on the base body. The switch element interacts with the spring arm via an operative contact. At least one switch element inner surface and/or spring arm outer surface involved in the operative contact is angularly inclined to the axis. Switch element rotation/displacement generates spring arm elastic deformation towards/away from the axis, thereby engaging/disengaging the thread engagement structure.

    Claims

    1-15. (canceled)

    16. An injector for implantation of an intraocular lens, comprising: a base body; an elongated actuation element, which projects at least partly into a rear section of the base body and which is movably guided along an actuation axis, wherein a movement of the actuation element into the base body is generated selectively by a push actuation along the actuation axis or by a screw actuation about the actuation axis, and wherein the actuation element features an external thread at least on one section; and a switch element arranged on the base body; wherein; at least one spring arm is arranged at the base body, the spring arm having a thread engagement structure on an inner surface facing the external thread; and the switch element interacts with the spring arm and is rotatable about the actuation axis or displaceable along the actuation axis, the switch element interacting with the spring arm via an operative contact, at least one inner surface of the switch element involved in the operative contact and/or an outer surface of the spring arm involved in the operative contact is formed inclined at an angle to the actuation axis, so that upon rotation or upon displacement of the switch element an elastic deformation of the spring arm towards the actuation axis and away from the actuation axis, the latter by itself, is generated, whereby the thread engagement structure is selectively engaged or disengaged with the external thread.

    17. The injector according to claim 16, wherein: the switch element is a sliding element and is displaceably arranged in or on the base body; and/or the switch element is ring-shaped or hull-shaped and encloses the actuation element partially or completely.

    18. The injector according to claim 16, wherein: the switch element forms a body of rotation, which is manually rotatable about the actuation axis and which features an inner passage, the at least one spring arm projecting through the inner passage and the actuation element extending through the inner passage.

    19. The injector according to claim 18, wherein: the inner surface is formed in the inner passage of the switch element and forms an inner cone circumferentially arranged about the actuation axis, so that by an axial displacement of the switch element in the actuation axis the outer surface of the spring arm contacts with different radii of the inner surface within the switch element.

    20. The injector according to claim 16, wherein: the base body features a receiving section with a passage, through which the actuation element extends and the actuation element is movably received at or on the receiving section, whereas the at least one spring arm extends into an area between the inner surface of the switch element and the actuation element.

    21. The injector according to claim 16, wherein: the switch element is received at or on the receiving section in such a manner that the actuation element is axially movable along the actuation axis and/or is rotatable about the actuation axis.

    22. The injector according to claim 16, wherein: the at least one spring arm comprises at least one spring arm, two spring arms facing each other, or three, four or more spring arms arranged on a rear end of the receiving section or arranged at the base body in a position within the receiving section.

    23. (canceled)

    24. The injector according to claim 16, further comprising: at least one groove provided in an outer circumference of the receiving section; and at least one pin formed at an inside of the switch element, the pin being guided in the groove.

    25. The injector according to claim 16, wherein: the switch element is arranged on the receiving section by a threaded connection, so that upon rotation of the switch element about the actuation axis, the switch element performs a movement along the actuation axis so that by an axial displacement of the switch element along the actuation axis the outer surface of the spring arm contacts with different radii of the inner surface within the switch element.

    26. The injector according to claim 20, wherein: the base body features a wing handle, and the receiving section adjoins the rear side of the wing handle as an extension.

    27. The injector according to claim 16, wherein: the injector features a receiving means for a lens cartridge, an intraocular lens being inserted into the lens cartridge, and the lens cartridge with the intraocular lens is insertable into the receiving means.

    28. The injector according to claim 16, wherein: the injector features a receiving chamber, which is formed in the base body and/or in a lens guide section arranged at a front end of the base body, an intraocular lens being inserted in the receiving chamber, so that the injector forms an individually manageable and tradable unit with the inserted intraocular lens.

    29. The injector according to claim 16, further comprising: a piston received in the base body, the piston being axially displacable by the actuation element via a rotary joint.

    30. The injector according to claim 26, wherein: the base body is formed in one piece with the receiving section and with the wing handle made from a plastic body; and a lens guide section with a tip-side ejection nozzle for ejecting the intraocular lens is arranged at a front end of the base body.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0035] Further measures to improve the invention are described in more detail below, together with a description of a preferred embodiment of the invention shown in the Figures. It is shown in:

    [0036] FIG. 1 a perspective view of an injector for implantation of an intraocular lens into a human eye, wherein the switch element of the injector is arranged in a position, in which the injector can be operated by a push actuation;

    [0037] FIG. 2 a view of the injector as shown in FIG. 1, wherein the switch element of the injector is arranged in a position, in which the injector can be operated by a screw actuation;

    [0038] FIG. 3 an exploded view of the main components of the injector;

    [0039] FIG. 4 a cross-sectional view of the injector in a perspective illustration, wherein the operating state of the injector is set up for push actuation;

    [0040] FIG. 5 the illustration of the injector as shown in FIG. 4, wherein the switch element has been rotated relative to the position shown in FIG. 4, so that the injector is set up for screw actuation;

    [0041] FIG. 6 a perspective view of the injector with a partially cross-sectional view of the switch element;

    [0042] FIGS. 7 and 8 a cross-sectional view through the arrangement of the switch element on the base body with a push actuation (FIG. 7) and with a screw actuation (FIG. 8).

    DETAILED DESCRIPTION OF THE INVENTION

    [0043] FIGS. 1 and 2 show a perspective view of the injector 1, which can be used to implant an intraocular lens into a human eye. The injector 1 features a base body 10 as its main structural component, and an elongated actuation element 11 with a handle 31 at the rear end is partially inserted into the base body 10. The actuation element 11 has a section with an external thread 13 over its essential length, and the actuation element 11 is partially inserted into the rear end of the base body 10 in such a way that the handle 31 is formed at a free end of the actuation element 11.

    [0044] At the front side of the base body 10, a lens guide section 27 is arranged in which the intraocular lens is inserted in a manner not shown closer. The main component of the base body 10 is approximately cylindrically or ergonomically designed for handling by a human hand and has an elongated extension, and the injector 1 with the base body 10, with the lens guide section 27 at the front end and with the actuation element 11 inserted in the rear end extends longitudinally in an actuation axis 12. The actuation axis 12 also forms the axis of rotation for the rotatable actuation element 11 with the handle 31 at the end.

    [0045] For improved handling there is a wing handle 20 on the rear part of the base body 10, so that the injector 1 can be grabbed between the index finger and the middle finger with the wing handle 20, while the thumb can be used to push on the handle 31 on the rear side. At the back side of the wing handle 20 follows a switch element 16, which is mounted to the base body 10 so that it can rotate about the actuation axis 12, and the switch element 16 has a passage through which the actuation element 11 extends. The switch element 16 is arranged on the base body 10 in such a way that it has no direct contact with the actuation element 11 and does not directly interact with it.

    [0046] On the lens guide section 27, a load opening 32 is shown through which a viscoelastic medium can be inserted before the injector 1 is operated. The viscoelastic medium then wets the inserted intraocular lens and the inner lumen, especially in the lens guide section 27, in order to promote the process of expelling the intraocular lens or to enable the intraocular lens to be expelled without damage.

    [0047] The switch element 16 of the injector 1 forms a means to switch the operation mode of the injector 1 between a push actuation P and a screw actuation S. FIG. 1 shows a position of the switch element 16, which allows a push actuation P, while FIG. 2 shows the switch element 16 in a rotated position, which allows a screw actuation S.

    [0048] In order to form a means of switching the mode between the push actuation P and the screw actuation S, the switch element 16 has an inner surface 17 on the inside, which varies its radius over the circumferential course of the switch element 16 in the manner of an Archimedean spiral at least in sections, in such a way that, during a rotation, the internal spring arms 14, which are arranged in a fixed position on the base body 10, can be moved towards the external thread 13 of the actuation element 11 where the switch element 16 tapers, and can be moved away from the external thread 13 when the switch element 16 widens in the opposite direction and reverses the tapering effect.

    [0049] FIG. 1 shows a setting position of the switch element 16, according to which the spring arms 14 are located in a peripheral area on the inner surface 17 of the switch element 16, in which the spring arms 14 can spring open automatically, so that the distance to the actuation axis 12 increases and so that the spring arms 14 release the external thread 13 on the actuation element 11.

    [0050] On the other hand, FIG. 2 shows the switch element 16 in a rotated position, according to which the spring arms 14 are pressed by the smaller inner radius at this point into the external thread 13 of the actuation element 11 and engage in it, so that in this position the screw actuation S for travelling the actuation element 11 into the body 10 is possible.

    [0051] The further the actuation element 11 is pushed or screwed into the base body 10, the further the intraocular lens is moved forward in the direction of a front side ejection nozzle 28 at the lens guide section 27. A more detailed illustration of the function for switching the injector 1 between the push actuation P and the screw actuation S is shown in FIG. 3 in an exploded view of injector 1.

    [0052] FIG. 3 shows the injector 1 in an exploded view, in which the essential parts of the injector 1 are shown, whereby further parts of the injector 1 are present, which are not shown, as they are not necessary for the presentation of the present invention, but which are also supposed to be part of the injector 1 according to the invention, so that the illustration is not to be understood conclusively.

    [0053] The illustration in FIG. 3 shows the base body 10 separated from the lens guide section 27, and a lens guide section 27, which is shown in alignment with the actuation axis 12, is designed with a receiving chamber 23, in which an intraocular lens 24 is inserted (visible with a haptic on one side), and another lens guide section 27 is shown below which forms an alternative design and has a receiving means 30 for receiving a lens cartridge 29, in which the individually shown intraocular lens 24 is inserted. Once the lens cartridge 29 is inserted into the receiving means 30, the intraocular lens 24 can be expelled out of the front of the ejection nozzle 28 by a piston 25 into the posterior chamber of the human eye.

    [0054] For this purpose, the piston 25 performs a linear movement in the actuation axis 12, and if the actuation element 11 is screwed into the base body 10 with a screw actuation, a rotary joint 26 is used to ensure that the rotational movement of the actuation element 11 is not transmitted into the piston 25.

    [0055] Behind the wing handle 20, the base body 10 features said receiving section 19, onto which the switch element 16 is snapped, and it can be rotated about the actuation axis 12. For this purpose, the outer surface of the receiving section 19 features a groove 21, which runs in the circumferential direction in the shown section A, so that the switch element 16 can be rotated in an axially defined certain position about the actuation axis 12. A section B of the groove 21 is used for sliding on said switch element 16, wherein a kind of a detent is performed, which cannot be overcome itself by the switch element 16, so that the switch element 16 is inhibited to leave the section A and pass into section B of the groove 21 of the receiving section 19.

    [0056] The receiving section 19 is sleeve-shaped and, in particular, is attached in one piece to the base body 10 at the back of the wing handle 20 and thus forming a section of the base body 10. Inside the receiving section 19, two spring arms 14 are arranged in an exemplary manner, wherein the spring arms 14 are rooted either on the inner surface of the receiving section 19 or on the back of the base body 10 or on the wing handle 20, respectively. Thus, the spring arms 14 can be moved resiliently inwards by elastic deformation towards the actuation axis 12 or outwards away from the actuation axis 12. In a non-activated arrangement of the spring arms 14, they feature a sufficient distance to each other, according to which the external thread 13 on the actuation element 11 can be moved freely and centrally between the two spring arms 14. In the commercial delivery condition of the injector 1, the switch element 16 therefore should be set in a position allowing for push actuation in order to non-stress the spring arms 14.

    [0057] If the switch element 16 is snapped onto the receiving section 19, the switch element 16 can be rotated on the receiving section 19 in such a way that different circumferential positions of the inner surface 17 with a varying inner radius Ri come into contact with the outer surface 18 of the spring arms 14. As the inner radius Ri of the inner surface 17 changes along the continuous circumference, i.e. the inner radius Ri tapers or contracts inwardly, the spring arms 14 can either be pressed radially inward or automatically spring back outwards due to their intrinsic elasticity. Thus, depending on the position of the switch element 16 about the actuation axis 12, it is possible to adjust whether a thread engagement structure 15 on the inside of the spring arms 14 engages with the external thread 13 or whether the thread engagement structure 15 is disengaged from the external thread 13. If the thread engagement structure 15 on the spring arms 14 is in engagement with the external thread 13 on the actuation element 11, the injector 1 can be used by screw actuation S, and if the thread engagement structures 15 on the spring arms 14 are out of engagement with the external thread 13 on the actuation element 11, the injector 1 can be used by push actuation P.

    [0058] FIGS. 4 and 5 show further perspective views of the injector 1 in a cross-section through the base body 10. For clarification, FIG. 4 shows the injector 1 in a state, in which it can be used by push actuation P, and FIG. 5 shows the injector 1 in a state, in which it can be used by screw actuation S.

    [0059] If the injector 1 is to be provided in the operating mode of the push actuation P, the switch element 16 is rotated counterclockwise with respect to the viewing direction of the handle 31 until it is in the rotational position shown in FIG. 4. In this rotational position, the inner radius of the inner surface 17 in the contact position of the spring arm 14 is enlarged, so that the spring arm 14 relaxes and has a maximum distance to the actuation axis 12. In this position, the thread engagement structure 15 on the inside of the spring arm 14 does not engage with the external thread 13 of the actuation element 11. Accordingly, the actuation element 11 can be moved freely along the actuation axis 12 and the actuation element 11 can be pushed forward together with the piston 25 towards the lens guide section 27.

    [0060] In FIG. 5, the switch element 16 is in a clockwise rotated position, according to which the inner radius of the inner surface 17 at the point of contact with the spring arm 14 is reduced to such an extent, that the thread engagement structure 15 is engaged with the external thread 13 on the actuation element 11. In this position of the switch element 16, the actuation element 11 can only be displaced in the actuation axis 12 if it is set in rotary motion by means of the handle 31 about the actuation axis 12 and finally screwed into the base body 10. The opposing thread engagement structures 15 of the spring arms 14 thus form a thread passage in the base body 10, through which the actuation element 11 can be screwed into the back of the base body 10. Only then the piston 25 can be moved forward in the direction of the lens guide section 27 and the intraocular lens can be expelled from the ejection nozzle.

    [0061] FIG. 6 shows another perspective view of the injector 1 with a partially cut switch element 16, which is snapped onto the receiving section 19. Inside the switch element 16, there are pins 22, one of which is visible by means of the cut and which runs in the grooves 21. Thereby, the switch element 16 can first be placed on the receiving section 19 via section B of the groove 21 and then be rotated about the actuation axis 12 within section A of the groove 21.

    [0062] The spring arms 14 are designed with outer surfaces 18 on the rear side in such a way that they can slide along the inner surface 17 of the switch element 16, when the switch element 16 is rotated about the actuation axis 12. Since the spring arms 14 are rooted on the inside in the receiving section 19 or on the rear side of the base body 10, the spring arms 14 do not shift in their circumferential position about the actuation axis 12. Only in this way the outer surfaces 18 of the spring arms 14 come into contact with the inner surface 17 in different circumferential positions of the switch element 16, when the switch element 16 is rotated, so that the shifting of the spring arms 14 radially towards the actuation axis 12 and radially away from the actuation axis 12 can be produced by the varying inner radius Ri.

    [0063] FIGS. 7 and 8 show a cross-sectional view through the arrangement of the switch element 16 in arrangement on the main body, represented by the wing handle 20. The actuation element 11 extends through the switch element 16, and the actuation axis 12 is perpendicular to the plane of the figures.

    [0064] FIG. 7 shows the position of the switch element 16, in which the push actuation is enabled, and FIG. 8 shows a position of the switch element 16, in which the screw actuation is enabled.

    [0065] To set the push actuation, the spring arms 14 are in contact with the inner surface 17 via their outer surfaces 18 at a circumferential position where the inner radius Ri is particularly large. The elastic springing of the spring arms 14 causes the thread engagement structure 15 to disengage from the external thread 13 on the actuation element 11.

    [0066] As shown in FIG. 8, the switch element 16 can be rotated clockwise to a setting position, which allows screw actuation. In this position the outer surface 18 of the spring arm 14 is in contact with the inner surface 17 at a circumferential position where the inner radius Ri is smaller and the thread engagement structure 15 inside the spring arms 14 is brought into engagement with the external thread 13 on the actuation element 11. In this position, the actuation element 11 can only be screwed into the base body by a screwing movement.

    [0067] The invention is not limited in its entirety to the preferred embodiment given above. Rather, a number of variants are conceivable which make use of the solution presented even if the design is fundamentally different. All features and/or advantages arising from the claims, the description or the figures, including constructional details or spatial arrangements, may be essential to the invention, both individually and in various combinations.

    REFERENCE NUMBERS

    [0068] 10 base body [0069] 11 actuation element [0070] 12 actuation axis [0071] 13 external thread [0072] 14 spring arm [0073] 15 thread engagement structure [0074] 16 switch element [0075] 17 inner surface [0076] 18 outer surface [0077] 19 receiving section [0078] 20 wing handle [0079] 21 groove [0080] 22 pin [0081] 23 receiving chamber [0082] 24 intraocular lens [0083] 25 piston [0084] 26 rotary joint [0085] 27 lens guide section [0086] 28 ejection nozzle [0087] 29 lens cartridge [0088] 30 receiving means [0089] 31 handle [0090] 32 load opening [0091] A groove section [0092] B groove section [0093] Ri inner radius [0094] P push actuation [0095] S screw actuation [0096] U1 circumferential segment [0097] U2 circumferential segment