INJECTOR FOR AN INTRAOCULAR LENS

Description

Field of invention

[0001] The invention relates to an injector for an intraocular lens. In particular, the invention relates to an injector designed as a disposable system with which an intraocular lens can be delivered and positioned in the patient's eye. Background of the invention

[0002] Injectors have become established for the insertion of intraocular lenses as a replacement for the eye's natural lens, as is done particularly in the treatment of cataracts.

[0003] Such an injector includes a piston through which the lens is transferred into the patient's eye via a cannula.

[0004] With such injectors, it is particularly advantageous that the lens can also be transported into the eye in a folded state, so that the channel required for the cannula has a smaller cross-section than the channel that has to be cut to introduce an unfolded lens into the eye.

[0005] Once the lens reaches the tip of the cannula, the remaining advance distance required is quite short. In particular, even with lenses that have a haptic, this distance is usually less than 12 mm.

[0006] Furthermore, the tapered cannula can initially increase the force required for propulsion, only to then decrease abruptly once the lens has partially left the cannula.

[0007] Therefore, it can be difficult to maintain the exact position while pressing on the piston.

[0008] The patent specification EP 2 150 204 B1 therefore provides that the piston has a thread via which a rotary movement on the handle of the piston is converted into a linear movement of the same.

[0009] The patent specification, which would otherwise require the user to turn the piston for the entire dispensing process, provides that the thread of the piston is only engaged when desired by the user, via a cam guide with locking balls.

[0010] A disadvantage of the injector as described in this document is that the user must first actuate the ring with the locking cam to engage the balls with the thread. The user must then reposition their grip to hold the injector against the housing and subsequently advance the piston further by turning the handle of the piston rod.

[0011] Changing grip can lead to positioning errors. Furthermore, it is difficult to switch repeatedly between using the rotary element and advancing the lens by pressing the handle. However, switching back to manual advancing can be useful in certain situations, especially if the lens has already partially emerged and is optimally positioned. Some users also prefer to advance the lens using either a rotary element or by pressing.

[0012] Furthermore, the injector, according to the prior art described above, is quite complex in its design. In particular, metal balls are generally used for a locking mechanism, meaning that the injector is partly made of plastic and partly of metal, which in turn complicates its disposal or recycling.

[0013] Document EP 3 476 375 A1 shows an injector in which a rotary element is rotatably mounted on the injector housing. Object of the invention

[0014] In contrast, the invention is based on the objective of at least reducing the aforementioned disadvantages of the prior art.

[0015] In particular, it is an object of the invention to provide an injector for delivering an intraocular lens which is both easy to manufacture and enables simple and safe use. Summary of the invention

[0016] The object of the invention is already solved by an injector for an intraocular lens according to claim 1.

[0017] Preferred embodiments and further developments of the invention can be found in the subject matter of the dependent claims, the description and the drawings.

[0018] The invention relates to an injector for an intraocular lens, comprising a housing with a cannula, a receiving chamber for the intraocular lens and a piston that is movable within the housing.

[0019] The receiving chamber can, in particular, be formed integrally with the cannula as a single component, which is connected, for example, to a main housing of the injector. According to one embodiment, a magazine containing the intraocular lens can be placed on the receiving chamber. The lens can then be transferred into the receiving chamber via a folding element, folding simultaneously.

[0020] By advancing the piston, the lens can then be transferred to the tip of the cannula and delivered into the patient's eye.

[0021] According to the invention, the injector comprises a rotary element for displacing the piston, wherein the rotary element is mounted on the piston so as to be rotatable as well as axially and linearly displaceable without rotating.

[0022] For rotatable mounting, the rotating element can be guided, in particular, on a piston rod of the piston. Specifically, the rotating element and piston rod can form an interference fit. The rotating element can thus be turned against the friction of the interference fit and sits on the piston rod without play.

[0023] The piston, in turn, is axially displaceable in the distal direction relative to the rotating element.

[0024] In addition to being advanced via the rotary element, it is also provided that the piston can be advanced manually by pressing on a handle at the proximal end of the piston.

[0025] The rotating element, particularly in its initial position, may be positioned so far from the injector's main housing that a thread on the rotating element does not engage with a corresponding thread on the injector's main housing. In this case, the user can only advance the piston by pressing on a proximal end of the piston.

[0026] The rotating element is then attached to a mount on the system.

[0027] Further advancement can now be achieved via the rotary element by engaging a thread of the rotary element, so that the piston can now also be pushed forward via the rotary element.

[0028] According to one embodiment of the invention, it is provided that, when the rotary element is already engaged at the receptacle, the piston can also be advanced further by pressing on the proximal end of the piston.

[0029] The user can therefore switch between feeding by pressing on the piston or feeding by rotating the rotary element, as desired.

[0030] The receptacle for the rotating element is preferably located adjacent to a handle, in particular a wing handle.

[0031] The handle can serve as a counter-support for the user when pushing the piston forward.

[0032] To operate the rotary element, the user only needs to place the fingers of one hand on the rotary element, whereby the hand of the user located at the proximal end can be used for guidance during rotation.

[0033] If the user decides not to completely squeeze the lens out of the cannula by turning the rotating element, the housing with the rotating element, whose thread is now engaged, can only serve as a counter-holder to complete any remaining ejection process by pressing on the piston.

[0034] The invention enables the simple design of an injector consisting of only a few parts. In particular, metal parts can be largely, and preferably completely, dispensed with.

[0035] Furthermore, as already explained above, particularly simple operation and preferably also the easy switching between feed by turning and feed by pushing are made possible.

[0036] According to the invention, the injector is designed such that the thread of the rotating element engages with the receptacle when the intraocular lens is already in the cannula.

[0037] The transfer from the receiving chamber to the cannula, which preferably tapers conically towards the front, is therefore preferably carried out solely by pressing on the distal end of the piston.

[0038] Specifically, the thread is designed to engage with the receptacle when the intraocular lens is positioned directly in front of the cannula tip. Therefore, only the final part of the delivery process, namely squeezing the lens out of the cannula tip, is performed via the rotating element.

[0039] In one embodiment of the invention, the rotating element on the piston is secured against displacement in the distal direction by a retaining ring.

[0040] The retaining ring may, in particular, have a slot and thus be bent apart and placed on the piston rod.

[0041] This allows for easy manufacturing and assembly.

[0042] Furthermore, the retaining ring acts as a stop, which moves the piston forward when the rotary element is turned.

[0043] It is understood that when using the rotary element to advance the piston and then advancing it further by pressing on the piston, the rotary element will only reach its stop against the retaining ring once the ring is turned a further time. However, such a situation will rarely occur when using the injector according to the invention. If the user decides to switch from advancing the piston by turning it back to advancing it by pressing on the piston, the lens is usually already positioned as desired and is then simply pressed out by a final, single press of the piston to unfold in the eye.

[0044] In one embodiment of the invention, an elastic stopper is provided between the piston and the housing, which acts as a stop for the piston in its end position. The elastic stopper can, for example, be inserted into the housing or attached to the piston.

[0045] In the final position, a "soft" stop is provided, which makes reaching the final position easily perceptible to the touch.

[0046] In one embodiment of the invention, the piston is locked in a starting position in a main housing of the injector.

[0047] In particular, the piston can include a locking hook which engages in a recess in the main housing during assembly. The piston can then no longer be retracted.

[0048] If, on the other hand, the piston is now pushed forward in a distal direction, the locking hook springs in and allows further advancement of the piston.

[0049] The piston rod can have a cross-shaped cross-section.

[0050] This facilitates the storage of the piston rod in the housing.

[0051] Furthermore, the piston rod can thicken gradually in the proximal direction. In particular, a front part of the piston rod can have a smaller outer diameter than a rear part of the piston rod.

[0052] The rear part of the piston rod is more robust and can be guided in a main housing, whereas the front part protrudes from the main housing into the receiving chamber or, if advanced further, into the cannula.

[0053] The housing can have a segmented external thread for the rotating element.

[0054] This facilitates the engagement of the internal thread of the rotating element.

[0055] A thread within the meaning of the invention is understood to be all components in engagement via which a rotary movement of the rotating element can be converted into an axial linear movement of the piston.

[0056] In particular, the engagement elements on the mounting on the main housing do not need to be designed as threaded sections with a pitch, but the arrangement of ribs which engage with the internal thread of the rotating element is sufficient.

[0057] In one embodiment of the invention, the rotary element comes to rest against the receptacle after the piston has advanced by more than 10 mm and / or less than 30 mm. The piston is preferably displaceable by more than 5 mm, more preferably more than 8 mm and / or less than 15 mm, more preferably less than 12 mm, solely by rotation of the rotary element.

[0058] The rotating element can have an internal thread with a pitch between 1.5 and 7 mm.

[0059] Furthermore, the rotating element can have an outer diameter of 18 to 28 mm.

[0060] The disclosure further relates to a method for dispensing an intraocular lens from an injector. The injector described above can be used, in particular, to carry out the method.

[0061] The procedure can be carried out in particular for testing purposes, such as a functional test of the injector.

[0062] According to the procedure, the lens is initially arranged in a folded state in a receiving chamber of the injector.

[0063] In particular, the lens can be folded by closing a lid with a folding element.

[0064] Then, by pressing the handle of an axially movable piston, the lens is transferred from the receiving chamber into a cannula. The cannula tapers, particularly towards its distal end.

[0065] According to the invention, while the intraocular lens is located in the cannula, a rotating element mounted on a piston rod comes into contact with a receptacle for the rotating element.

[0066] The piston can then be advanced by further pressing on the handle or by turning the rotating element to release the intraocular lens from the cannula. A key aspect of the invention is that, initially, the lens is transferred from its receptacle into the cannula solely by pressing on the piston.

[0067] This has the advantage that this step can be completed relatively quickly.

[0068] In particular, this procedure step can be performed if the cannula has not yet been inserted into the user's eye.

[0069] This procedural step can be performed in particular by the assistant of the eye surgeon.

[0070] If the rotary element and piston rod form an interference fit, a haptically perceptible resistance indicates that the rotary element has now come into contact with the mount.

[0071] The assistant can now hand the prepared injector to the eye surgeon, who then has complete freedom to choose whether to press the lens into the eye by pressing on the piston or using the rotating element. Brief description of the drawings

[0072] The subject matter of the invention will below be described with reference to an exemplary embodiment shown in the drawings. Figs. 1 to 9 will be explained in more detail. Figs. 1 to 4 These are isometric views of an exemplary embodiment of an injector in an operating state. They illustrate how the injector is used to deliver an intraocular lens. Fig. 5 This is a longitudinal section of the injector. Fig. 6 This is an isometric view of the piston. Fig. 7is a perspective view of the main casing at its proximal end. Fig. 8 and Fig. 9 These are detailed views of a longitudinal section in the area of ​​the rotating element in various operating states of the injector. Detailed description of the drawings

[0073] Fig. 1 is an isometric view of an embodiment of an injector according to the invention 1.

[0074] The injector 1 comprises a cannula 10 with a tip 11, through which an intraocular lens (not shown) can be delivered into the eye of a patient (not shown).

[0075] For this purpose, the intraocular lens is inserted into the receiving chamber 12 and then pressed out of the cannula 10 by means of the piston 20.

[0076] In this embodiment, an intraocular lens located in a magazine (not shown) can be inserted into the receiving chamber 12 by first placing the magazine on the injector, in particular on the front part with the cannula 10 and the receiving chamber.

[0077] The image shown here is of the unassembled state, in which the movable folding element 13 is not yet inserted into the support 16.

[0078] In the assembled state, a pin 18 of the folding element 13 sits in the guide groove 17 of the carrier. This allows a defined movement of the folding element 13 during the pressing of the lens.

[0079] Before the lens is pressed out, the fully assembled cover 14 is closed with the folding element, and the folding element 13 connected to the cover 14 transfers the intraocular lens into the receiving chamber 12, where it is immediately folded. Usually, before folding, the folding element 13 is advanced into the cover 14, and then the cover 14 can be closed.

[0080] The following drawings also do not show how the lid is closed with the folding element.

[0081] The basic principle of the invention can be applied to all types of intraocular lens injectors, particularly those that are already preloaded with a lens. The injector 1 further comprises the main housing 40, in which the piston 20 is guided. The piston 20 comprises the piston rod 21, which projects into the main housing 40 and includes the handle 22 at its proximal end.

[0082] In Fig. 1The starting position of injector 1 is shown, i.e., the operating state before injector 1 is used.

[0083] In this operating state, the rotary element 30 is rotatably mounted on the piston rod 21 and is still spaced apart from the receptacle 43 for the rotary element 30.

[0084] The rotating element 30 includes an internal thread 31.

[0085] In this embodiment, the rotating element 30 is essentially cylindrical in shape and includes a profile 32 to make it easier to grip.

[0086] The user can now advance the piston 20 until the rotary element 30 comes into contact with the receptacle 43.

[0087] The receptacle 43 includes a thread 48, which in this embodiment is segmented to facilitate demolding the thread 31 of the rotary element 30 in an injection mold.

[0088] Adjacent to the injector's opening, in a distal direction, is a winged handle 41, which the user can use to hold the injector 1, for example, with their index and ring fingers. This handle provides a counter-support when the user pushes the piston 20 forward on the handle 22. In particular, this allows the injector to be used with one hand by pushing the handle 22 forward with the palm of the hand while two fingers hold the injector 1 on the winged handle 41.

[0089] On the underside, distal to the wing handle 41, there is another handle 42, which can be used optionally, for example to make a fine adjustment of the position of the tip 11 of the cannula 10 or to serve as a counter-holder for the middle finger.

[0090] As in Fig. 2As shown, the piston 20 is first pushed forward until the rotary element 30 comes into contact with the receptacle 43, which in this embodiment forms the proximal end of the main housing 40.

[0091] The intraocular lens has now been transferred from the receiving chamber 12 into the cannula 10. It is understood that the lid 14 is closed (not shown). The rotating element 30 can now be moved further in a proximal direction relative to the piston 20. However, due to an interference fit between the rotating element 30 and the piston 20, the user feels resistance, which signals that the intraocular lens is now ready to be pressed into the eye.

[0092] The user can now, as described below, Fig. 3 and Fig. 4 As shown, turn the rotary element 30 to advance the piston 20 further.

[0093] Alternatively, the user can continue pushing the handle 22 forward, thus pushing the intraocular lens out of the cannula 10 without using the rotating element 30. If the user uses the rotating element, he can, as described in Fig. 4 As shown, the rotary element 30 is rotated until the piston 20 reaches its end position. Preferably, the rotary element 43 does not reach the receptacle 43 in its end position, but the end position is determined solely by an elastic stopper (see 4 in Fig. 6 ) defined.

[0094] The intraocular lens has now been transferred into the patient's eye.

[0095] Fig. 5 is a longitudinal section of the injector in its initial state.

[0096] In this embodiment, the front housing part with the cannula 10 includes a groove 15 with which it is secured against the main housing 40.

[0097] The cannula 10 can therefore be snapped onto the main housing 40.

[0098] The piston rod 21 is divided into several sections.

[0099] A front section 21a has a smaller diameter than the rear section 21b.

[0100] Section 21a is designed to accommodate the tip 23 made of elastic material.

[0101] In the distal front area of ​​the main housing 40 there is a guide 44 for the front part 21a of the piston rod 21.

[0102] A rearward part 21b of the piston rod is guided in the main housing 40. In this area, the piston rod 21 includes a locking hook 24, which is engaged in the main housing 40 during assembly and then only allows movement of the piston 20 in a distal direction.

[0103] The rear part 21b of the piston rod 21 initially comprises a stage 25 in the area of ​​the rotating element 30.

[0104] This is followed by a groove 26 in which the retaining ring 2 sits. The retaining ring 2 forms a stop for the rotating element 30 in the distal direction.

[0105] In its initial state, the rotary element 30 is located at this stop.

[0106] In order to provide a stop in the end position of the piston 20, an elastic stopper 4 is pushed onto the piston 20 in this embodiment.

[0107] The front guide 44 forms a wall against which the elastic stopper 4 comes to rest in the end position, thus ending the feed by means of a spring-loaded stop. According to another embodiment, the elastic stopper can also be inserted into the main housing instead of being pushed onto the piston (not shown).

[0108] Fig. 6 This is a perspective view of piston 20 including retaining ring 2.

[0109] The retaining ring 2 has a slot 3, through which it can be widened and inserted into the groove of the piston rod 21.

[0110] Both the front part of the piston rod 21a and the rear part 21b of the piston rod 21 have a cross-shaped cross-section in order to slide in a corresponding guide of the injector housing.

[0111] Furthermore, the elastic stopper 4 sits on the front part 21a of the piston rod 21.

[0112] This serves as a spring contact when the piston 20 reaches its end position.

[0113] Fig. 7 is a perspective view of the proximal end of the main casing 40.

[0114] The main housing includes a channel 46 for the piston rod, more precisely for the rear part (21b) of the piston rod.

[0115] An upper guide rail 45a and a lower guide rail 45b project into the channel 46. The piston rod is guided in the main housing 40 via these guide rails.

[0116] Fig. 8 A detailed illustration shows the position of the rotating element when it comes into contact with the system at mounting 43. This position corresponds to the illustration according to... Fig. 2 The rotary element 30, which is rotatably mounted on the piston rod 21 with the wall 33, is moved forward together with the piston rod 21, i.e. in a distal direction, until the thread 31 comes to rest against the thread of the receptacle 43.

[0117] If the user continues to press on the proximal end of the piston 20, the piston rod 21 moves further forward. The retaining ring 2, in addition to the rotating element 30, acts only as a stop against movement of the piston rod 21 in the proximal direction (not shown).

[0118] Now turns, as in Fig. 9As shown, the user presses the rotary element 30 to expel the intraocular lens as slowly as possible; the wall 33, which rests against the retaining ring 2, pushes the piston rod 21 forward until the rotary element 30 reaches its end position.

[0119] Further rotation of the rotary element 30 is no longer possible, as further advance of the piston is blocked by the stopper. The retaining ring 2 therefore does not come into contact with the wall 47.

[0120] The invention made it possible to provide a simply constructed, yet very user-friendly injector for intraocular lenses. In particular, it allows for the optional use of a rotating element as the intraocular lens exits the injector's cannula. Reference symbol list

[0121] 1 Injector 2 Retaining ring 3 Slot 4 Elastic stopper 10 Cannula 11 Tip 12 Lens holder 13 Folding element 14 Cover 15 Groove 16 Carrier 17 Guide track 18 Pin 20 Piston 21 Piston rod 22 Handle 23 Tip 24 Detent hook 25 Step 26 Groove 30 Rotary element 31 Internal thread 32 Profiling 40 Main housing 41 Wing handle 42 Front handle 43 Receptacle for the rotary element 44 Guide for 21a 45a Upper guide rail 45b Lower guide rail 46 Channel for 21b 47 Wall 48 Thread

Claims

1. An injector (1) for an intraocular lens, comprising a housing with a cannula (10), a receiving chamber (12) for the intraocular lens, and a plunger (20) which can be moved within the housing and which is adapted to move the intraocular lens from the receiving chamber (12) through the cannula (10), wherein the injector (1) comprises a rotary element (30) for moving the plunger (20); characterised in that the rotary element (30) is mounted on the plunger (20) for rotation and axial translation thereon; wherein, in a starting position, the rotary element (30) is spaced apart from a seat (43) provided on a main housing (40), wherein the rotary element (30) is displaceable together with the plunger (20) until the rotary element (30) comes into contact with the seat (43) and then a thread (31) thereof engages with the seat (43).

2. The injector (1) according to the preceding claim, characterised in that the injector (1) is adapted so that the thread (32) engages with the seat when the intraocular lens is located inside the cannula (10), in particular when the intraocular lens is located immediately in front of a tip (11) of the cannula (10).

3. The injector (1) according to the preceding claim, characterised in that the intraocular lens can be pushed out of the cannula (10) by turning the rotary element (30).

4. The injector (1) according to any one of the preceding claims, characterised in that the rotary element (30) on the plunger (20) is secured against displacement in the distal direction by a locking ring (2).

5. The injector (1) according to any one of the preceding claims, characterised in that, at an end position, advancement of the plunger (20) is blocked by a resilient stopper (4).

6. The injector (1) according to any one of the preceding claims, characterised in that once the rotary element (30) has reached its end position, the plunger (20) can be further advanced using a handpiece (22), in particular over a distance of 1 to 8 mm.

7. The injector (1) according to any one of the preceding claims, characterised in that the intraocular lens is arranged in the receiving chamber (12) in a folded state; and / or in that the plunger (20) is latched to a main housing (40); and / or in that the rotary element (30) is substantially in the form of a circular cylinder having a proximal wall that has a central opening which, in cooperation with a plunger rod (21), defines a rotary bearing; and / or in that the plunger rod (21) has a cross-shaped cross section; and / or in that the seat (43) for the rotary element (30) has a segmented external thread (48); and / or in that the rotary element (30) engages on the seat (43) after an advancement of the plunger (20) by more than 10 mm and / or by less than 30 mm; and / or in that the plunger (20) is displaceable using the rotary element (30) by more than 5 mm, preferably more than 8 mm, and / or by less than 15 mm, preferably less than 12 mm; and / or in that the rotary element (30) has a thread (31) having a pitch between 1.5 and 7 mm; and / or in that the main housing (40), the plunger (20), and the rotary element (30) are made of plastics material; and / or in that the plunger (20) and the rotary element (30) define a rotary bearing with an interference fit; and / or in that the rotary element (30) has an outer diameter between 18 and 28 mm.