Observation device and method for observing eye

Abstract

To provide an observation device having a positioning unit for positioning an optical unit in a beam path of a microscope between a microscope objective and an eye to be observed, and to provide a method of observing an eye using the observation device.SOLUTION: A positioning unit (11) is provided, comprising a connection device (14), a positioning device (15), an accommodating device (16), and an optical unit (12). The optical unit comprises a lens for observing an eye fundus and a further optical element. The positioning unit comprises a pivoting mechanism (19) configured to allow the optical unit to pivot in and out of a beam path (13). The positioning unit can be coupled to a microscope using the connection device. The lens is arranged on the positioning device using the accommodating device. The accommodating device is made of a plastic material. The positioning device has a lens barrel pivotably disposed on the pivoting mechanism and made of metal.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an observation device having a positioning unit for arranging an optical unit in an optical path of the microscope between an objective lens of the microscope and in front of an eye to be observed, the positioning unit includes a connecting device, a positioning device, a housing device, and the optical unit, the optical unit includes a lens for observing the fundus and further optical elements, the positioning unit includes a turning mechanism, and by the turning mechanism, the optical unit can turn so as to exit from or enter into the optical path, the positioning unit can be coupled to the microscope by the connecting device, the lens is arranged in the positioning device by the housing device, relates to an observation device. Further, the present invention relates to a method for observing an eye using this type of observation device, and at least most of, preferably completely, the housing device is made of a plastic material. Further, the present invention relates to a method for observing an eye using this type of observation device.

Background Art

[0002] A microscope for performing ophthalmic surgery is typically used for surgery in the anterior region of the eye. When this type of procedure is also performed in the posterior region of the eye, it is necessary to add an observation device to the microscope that enables accurate focusing on this region of the eye. This type of observation device comprises at least one wide-angle lens and / or a retinoscope lens for observing each posterior part of the eye at a wide angle, where the retinoscope lens provides an intermediate image in the optical path in front of the objective lens of the microscope, and the intermediate image can be focused with the microscope. To focus on the intermediate image, it is necessary to shorten the optical path of the microscope, which can be performed by a corresponding setting mechanism for the microscope. However, during ophthalmic surgery, such a setting of the microscope is obstructive because it is necessary to switch between different fields of view regardless of the presence or absence of the retinoscope lens. As a result, a so-called reduction lens can be arranged in the optical path in front of the objective lens, where the reduction lens shortens the optical path of the microscope and is used together with the retinoscope lens. Two lenses are held as an optical unit by a positioning unit of the observation device directly fixed to the microscope, without the need for large adjustments of the microscope during surgery, and can be arranged in the optical path as required. The positioning unit typically comprises a connecting device by which the positioning unit can be coupled to the microscope. Furthermore, the positioning unit is designed such that each lens can easily enter or be inserted into, and removed from again, the optical path.

Summary of the Invention

[0003] This type of observation device is known, for example, from DE10 2011 002 940.A1. The retinoscope lens is designed to be adjustable along the optical path of the microscope by a screw drive so that the intermediate image of the retinoscope lens can be adjusted as accurately as possible to the focal length of the objective lens of the microscope.

[0004] This observation device is realized such that the ophthalmic lens can be moved along the optical path relative to the eye. In this case, it is preferable that when the ophthalmic lens is as close to the eye as possible, a relatively wide area of the eye can be clearly seen. However, at the same time, contact of the ophthalmic lens with the eye must be avoided. Therefore, in order to obtain a sharp image of as wide an area of the eye as possible, it is always necessary to vary the distance of the microscope relative to the eye and adjust it to the distance of the ophthalmic lens. During ophthalmic surgery, when it is necessary to change the distance of the ophthalmic lens relative to the eye for a particular treatment step, for example, when the aqueous humor of the eye has to be aspirated, this adjustment of the respective relative distances from the ophthalmic lens to the microscope and to the eye, and focusing the image thus obtained, has to be carried out again.

[0005] Currently, it is considered preferable that if the observation device and / or the positioning unit is made of plastic and can be used as a disposable product, its / their sterilization can be dispensed with. Thus, an observation device made of plastic and allowing only a single use of the observation device is known. DE10 2018 127 469.B4 shows such an observation device.

[0006] However, in this case, especially when the positioning device or the positioning unit is made of a fragile plastic rod, plastic, unlike metal, has the disadvantage that it cannot always be used with the desired accuracy required for the placement of the ophthalmic lens. Thus, when the ophthalmic lens enters or exits the optical path, there is a risk of displacement of the ophthalmic lens along the optical path or of a deviation across the optical path. Thus, typically, this requires correction of the position of the ophthalmic lens, which hinders the performance of ophthalmic surgery.

[0007] Therefore, the object of the present invention is to propose an observation device and method for observing the eye, which enables improved treatment during ophthalmic surgery.

[0008] This object is achieved by an observation device having the features according to claim 1, a microscope having the features according to claim 16, and a method having the features according to claim 17.

[0009] In an observation device according to the invention, having a positioning unit for arranging an optical unit in the optical path of the microscope, between the objective lens of the microscope and in front of the eye to be observed. The positioning unit comprises a connecting device, a positioning device, a housing device, and the optical unit. The optical unit comprises a lens for observing the fundus and further optical elements. The positioning unit comprises a swiveling mechanism, by which the optical unit can be swiveled so as to exit from or enter into the optical path. The positioning unit can be coupled to the microscope by the connecting device. The lens is arranged in the positioning device by the housing device. The housing device is made at least mostly, preferably completely, of plastic material. The positioning device has a lens barrel that is pivotably arranged on the swiveling mechanism. The lens barrel is made at least mostly, or completely, of metal.

[0010] The observation device according to the present invention can be arranged in a microscope by a connecting device and / or can be detachably connected thereto. In the present application, the lens is held by a positioning unit in the optical path of the objective lens between the eye to be observed and the objective lens, and the lens may be an ophthalmic lens. In the present application, it is intended that the lens be arranged such that the principal axis and / or the optical axis of the objective lens of the microscope passes through the center point of the lens. By means of a pivoting mechanism, an optical unit having a lens, which is preferably a lens having a positive refractive power, and a further optical element can enter and exit the optical path as required during ophthalmic surgery. In this case, it does not matter at all how the pivoting mechanism is designed. What is important is that the optical unit can be completely removed from the optical path and can be completely moved into the optical path. Therefore, the pivoting mechanism can also be recognized as a displacement mechanism, and by means of the displacement mechanism, the optical unit can be displaced parallel to the optical path.

[0011] Furthermore, it is preferable that the housing device for holding the lens is substantially made of a plastic material and the lens barrel is substantially made of metal. Thus, the pivotable lens barrel can be designed particularly stably and accurately, whereby, in the present application, it is possible to accurately arrange the lens and the further optical element in the optical path without the need to perform correction adjustment as in the case of a mere disposable product. At the same time, the fact that the housing device is made of plastic enables the housing device provided with the lens to be manufactured particularly cost-effectively. The manufacturing can be easily and massively carried out from the viewpoint of, for example, an injection molding process. Furthermore, this makes it possible to use the housing device as a disposable product. In the present application, the housing device can be arranged after an ophthalmic surgery has been performed. Sterilization of the housing device is not necessary. A new, sterilized-packaged housing device can be used for the subsequent performance of an ophthalmic surgery. The housing device can be easily arranged in the lens barrel and / or can be detachably connected thereto.

[0012] Additional optical elements can be arranged under the swivel mechanism. Since the positioning device has a lens barrel rotatably arranged on the swivel mechanism, it becomes possible to arrange additional optical elements within the lens barrel. Thus, it is particularly easy to arrange additional optical elements so that they can move within the lens barrel. In the present application, additional optical elements can also be easily protected from external influences.

[0013] A further optical element can be movable by a positioning device in a direction along the optical path with respect to the microscope. In the present application, by the movable arrangement of the further optical element below the pivoting mechanism, it is possible to adjust the optical path of the microscope provided with the further optical element and / or to shorten the optical path to such an extent that the intermediate image of the lens can be focused. If the further optical element can be moved along the optical path below the pivoting mechanism, a relatively large space can be used to move the further optical element along the optical path compared to the case where the further optical element is arranged above the pivoting mechanism. In this case, the distance between the pivoting mechanism and the objective lens of the microscope is relatively short, because this is the only way to ensure that the optical unit and / or the positioning device can be completely removed from the optical path. Due to the relatively large adjustment range of the further optical element, it becomes possible to adjust the observation device generally for different types of microscopes and use it for different types of microscopes. In this case, it is no longer necessary to design the further optical element separately for different microscopes having different optical paths. In addition, the lens can also be fixed in a position within the optical path and does not need to be moved along the optical path with respect to the microscope. It is only necessary to align the microscope with the eye with the lens. In this case, the adjustment of the optical path can be easily carried out by moving the further optical element. The lens and the further optical element are each composed of a plurality of optical components, and the optical components are connected to each other in each case and together form an optical element. The lens may be an ophthalmic lens, and the further optical element is at least one lens having a positive refractive power and configured to adjust the optical path, and the lens within the lens barrel is arranged to be movable in a direction along the optical path below the pivoting mechanism. The lens having a positive refractive power may be a so-called reducing lens, and the optical path of the microscope can be shortened by the reducing lens. Since the lens having a positive refractive power is movable along the optical path in the lens barrel below the pivoting mechanism, the adjustment of the optical path can be easily carried out within a relatively large adjustment range. The lens having a positive refractive power can be easily displaced along the optical path by a screw drive, a helix formed inside the lens barrel, or the like.In the present application, the lens barrel can be rotated at least partially. In the present application, a lens having a positive refractive power can be accommodated in a mount that is displaceable inside the lens barrel together with the lens.

[0014] The observation device may include a cover unit made of a plastic material for covering the rotatable lens barrel of the positioning device in a sterilized state. The cover unit can be realized relatively thinly so that the cover unit can be in close contact with the rotatable lens barrel. The plastic material may be a rigid or flexible plastic material. Further, the plastic material may be opaque or optically translucent. In particular, the cover unit can be configured such that the outside of the rotatable lens barrel is completely shielded from the environment by the cover unit. In the present application, the rotatable lens barrel can be manually grasped and operated by a surgeon without even the need for subsequent sterilization of the lens barrel. In the present application, it is only necessary to remove the cover unit that can be manufactured cost-effectively from the plastic material and replace it with a new sterilized cover unit that has not been used until then.

[0015] The cover unit may have an upper sterilization cover that at least partially covers the end face of the lens barrel and a lower sterilization cover that at least partially covers the circumferential surface of the lens barrel. Thus, the cover unit can be realized in two parts. The upper sterilization cover can be arranged above the end face of the lens barrel when the lens barrel is rotated out of the optical path. The lower sterilization cover can be arranged below the lens barrel. In this case, the lens barrel is surrounded by the cover unit on all sides. In particular, when the surgeon manually grasps the lens barrel at a position where it is rotated out of the optical path, the upper sterilization cover makes it possible to protect the end face of the lens barrel from being touched by them / her. It is also preferable if a gap is realized between the lens barrel and the connecting device such that the upper sterilization cover can be arranged when the lens barrel enters the optical path when the upper sterilization cover is used.

[0016] The cover unit can be realized with at least one connecting element, and when separating the cover unit from the positioning device, it is necessary to break the connecting element. The connecting element can be realized as a latch element that engages with a protrusion realized on the lens barrel or engages with a groove realized on the lens barrel. A plurality of connecting elements may be provided. The connecting element may be arranged or attached with flexibility so that the connecting element can easily contact the lens barrel. When the cover unit is removed from the positioning device and / or the lens barrel, it is necessary that the connecting element is configured such that the connecting element and / or the cover unit is broken. This prevents the cover unit from being reused by mistake.

[0017] The cover unit has at least one unsealing strip, and by means of the unsealing strip, the cover unit can be at least partially destructible. The unsealing strip can be realized to have a tab that can be easily grasped manually. The unsealing strip can be realized by a weak line or two parallel weak lines within the cover unit. When the cover unit is fixed to the positioning device and / or the lens barrel, for example, by a latch connection, the latch connection can be broken by manually operating the unsealing strip. This makes it possible to easily remove the cover unit from the positioning device and / or the lens barrel.

[0018] The housing device can be realized to include at least one connecting element, and when separating the housing device from the positioning device, it is necessary to break the connecting element. This also prevents the housing device from being reused by mistake after separation from the positioning device. The connecting element can be realized, for example, such that the connecting element breaks when the housing device is removed from the positioning device.

[0019] The housing device can be configured to have an additional lens barrel, which is preferably conical. The additional lens barrel can be directly attached to the lens barrel and fixedly connected thereto. The fixed connection can be realized, for example, by a latch connection. It is particularly suitable if the additional lens barrel is realized in a conical shape. In the present application, the lens barrel can be adjusted to the shape of the optical path such that the diameter of the additional lens barrel is relatively small at the lower end of the additional lens barrel. In the present application, the lens can be arranged at the lower end. It is also suitable if the additional lens barrel is closed. In the present application, the additional lens barrel can be realized in the form of a conical sleeve.

[0020] The additional lens barrel is composed of an upper part and a lower part, and the lower part can be loosely or spring-loaded and attached to the upper part such that the lower part is insertable into the upper part. The spring-loaded attachment can be realized by a compression spring, which is inserted into the upper part, and the lower part can be moved into the upper part against the spring force of the compression spring. Thereby, when the lens and / or the lower part may hit the eye of the person undergoing the surgery, it is possible to prevent the eye from being damaged in an undesirable way.

[0021] At least one manually operable projection may be configured on the lower part, and the projection is movable along the longitudinal slot through the longitudinal slot configured on the upper part. In the present application, since the surgeon grasps the projection and pulls it upward in the direction of the microscope so that the lower part is moved into the upper part, the surgeon can manually move the lower part in the direction of the optical path. Preferably, for this purpose, two opposing projections may also be realized on the lower part, and the projections are respectively engaged in the longitudinal slots facing each other on the upper part. When the optical unit needs to be pivoted out of the optical path, the surgeon can preferably use the function of manually moving the lower part away from the eye in the direction of the optical path. In particular, when the lens is extremely close to the eye to be operated on, the lens can be manually moved out of the dangerous area for the eye, and immediately after the manual movement, the optical unit can be pivoted out of the optical path. The same applies to the reverse movement of the optical unit into the optical path. In this case, the corresponding movement of the microscope is no longer required.

[0022] The positioning device may have a drive unit, and by the drive unit, the position of the further optical element can be set in the direction along the optical path. The drive unit can be operated completely manually or also electrically. It is essential that the further optical element can be displaced and arranged along the optical path by the drive unit. In this regard, it is also suitable if the drive unit is an automatic lock. If the further optical element is arranged in the lens barrel, the drive unit can also be realized at least partially or completely in the lens barrel.

[0023] The drive unit can be arranged on the lens barrel, above the pivoting mechanism, and / or below the pivoting mechanism, on the connecting device. Therefore, the drive unit may be arranged only on the lens barrel, or may be realized such that the drive unit is arranged on the connecting device and the lens barrel. Depending on the design of the drive unit, it may be suitable that only a part of the drive unit is realized on the lens barrel so that the work of the surgeon is not hindered by the protruding parts of the observation device.

[0024] The observation device may include a shielding unit that shields the optical path of the positioning unit, and the shielding unit may be composed of at least one optically shielded, i.e., closed, lens barrel. The positioning device and the housing device may, for example, realize this closed lens barrel. Thus, preferably, it is possible to avoid light sources, scattered light, etc. used during ophthalmic surgery from entering the optical path and having an unfavorable effect on the representation of the image of the eye observed by the surgeon via the optical unit. Thus, differences in brightness, reflections, etc. can be avoided.

[0025] The drive unit may include a stepping motor coupled to a coupler of the drive unit to the lens barrel via a belt drive, i.e., a transmission. In the present application, the stepping motor may be an electric motor, and by the electric motor, a specified number of rotations may be executed until a further optical element reaches a desired position in the lens barrel. For this purpose, the lens barrel may be realized to be partially rotatable so that the rotation of the stepping motor can be transmitted to the lens barrel via a belt drive and / or a transmission. The drive unit may, for example, include a sleeve within the lens barrel, and the sleeve may be realized to have a thin wire or a helix and is connected to the belt drive and / or the transmission by a coupler. In the present application, by the rotation of the sleeve that can be moved by the stepping motor, the raising and lowering of a further optical element and / or the movement of the optical element along the optical path can be executed.

[0026] The coupler is separable or connectable by the swiveling mechanism. Thus, it is particularly suitable when a stepping motor having a belt drive or a transmission is arranged above the swiveling mechanism of the connecting device. In the present application, the coupler may be arranged between the connecting device and the lens barrel such that the coupler is separated when the lens barrel is swiveled out of the optical path and the coupler is connected when the lens barrel is swiveled into the optical path. The coupler may be realized as a negative connection, a form connection, and / or a friction connection.

[0027] It is preferable when the connector is a magnetic connector composed of two rings capable of transmitting torque by a magnet, and the further optical element may be movable by the rotation of the lens barrel. The two coaxial rings may each have several magnets, and the magnets exert magnetic forces on each other so that torque can be transmitted by the rings attracting each other. The magnets can be arranged at regular intervals on the axial end faces of the respective rings. The poles of the magnets of each ring can be arranged alternately so that the rings are in a defined relative position when the connector is closed. In the present application, when a gap is provided between the rings, the rings and / or the connector are particularly suitable because they do not need to contact each other to transmit torque. By using this gap, a sterilization cover can be inserted into the connector and / or between the lens barrel and the connecting device.

[0028] The positioning unit may include a control device, and the control device is configured to transmit it to the microscope by detecting the turning of the optical unit that exits or enters the optical path. It can be easily detected by a sensor of the control device that the optical unit and / or the lens barrel enters or exits the optical path. In the present application, the control device can send a signal to the microscope about whether the optical unit has entered or exited the optical path. When a so-called inverter is provided in the microscope, the microscope can move the inverter into or out of the optical path in the microscope. In the present application, the transposition of the optical path and the mirror image of the intermediate image of the lens can be generated by the inverter, and as a result, when the optical unit enters the optical path, an image of the eye is shown to the surgeon in the correct position arrangement.

[0029] The positioning unit may include a control device, the rotation of the lens barrel can be detected by a sensor of the control device, and the drive unit can be controlled by the control device such that the additional optical element can be moved by the drive unit to a position assumed in the direction along the optical path. The sensor may be, for example, a Hall sensor disposed on the drive unit and / or the lens barrel. A plurality of marks such as marks and graduations can be disposed on the lens barrel so that the rotation and position of the additional optical element in the direction along the optical path can be detected by the sensor. Thus, this enables detection of the position of the additional optical element along the adjustment range. For example, when the optical unit and / or the lens barrel is pivoted out of the optical path, if an unintended rotation of the lens barrel or a rotation of the connecting device of the objective lens of the microscope occurs, when pivoted into the optical path, the additional optical element is no longer at the assumed position set by the surgeon before exiting the optical path and / or is no longer in focus. By the drive unit, the control unit can here move the optical element to a preset, assumed position and / or the focus of the optical unit. In the present application, there is no longer a need for the surgeon to operate the drive unit to correct the changed settings of the additional optical element.

[0030] The microscope according to the present invention includes the observation device according to the present invention. Further preferred embodiments of the microscope are provided by the description of the features of the dependent claims that refer to claim 1.

[0031] In the method according to the present invention for observing an eye using an observation device, an optical unit is disposed in the optical path of the microscope between the objective lens of the microscope and in front of the eye to be observed by the positioning unit of the observation device, the positioning unit includes a connecting device, a positioning device, a housing device, and the optical unit, the optical unit includes a lens for observing the fundus and an additional optical element, The positioning unit includes a swiveling mechanism, and by means of the swiveling mechanism, the optical unit is swiveled so as to exit from or enter into the optical path. The positioning unit is coupled to the microscope by the connecting device. The lens is arranged in the positioning device by the housing device. At least most, preferably completely, of the housing device is made of a plastic material. The lens barrel of the positioning device is swiveled. The lens barrel is arranged in the swiveling mechanism. At least most or completely of the lens barrel is made of metal. For the advantages of the method according to the invention, reference is made to the description of the advantages of the observation device according to the invention.

[0032] Further optical elements can be used for correcting refractive errors of the eye. By means of the further optical elements, it becomes possible to focus the intermediate image of the lens, so that the optical path of the microscope is adjusted and the refractive errors of the eye can also be corrected by the further optical elements.

[0033] Further preferred embodiments of the method are provided by the description of the features of the dependent claims that refer to claim 1.

[0034] Below, preferred embodiments of the invention are explained in more detail with reference to the accompanying drawings.

Brief Description of the Drawings

[0035] In the figures,

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0036] The combination of FIGS. 1 - 8 shows an observation device 10 having a positioning unit 11 for arranging an optical unit 12 within an optical path 13 of a microscope (not shown in more detail in this example). The observation device 10 can be arranged on the microscope between the objective lens of the microscope and in front of the eye to be observed. The positioning unit 11 includes a connection device 14, a positioning device 15, a housing device 16, and an optical unit 12. The optical unit 12 is composed of an ophthalmic lens 17 and a lens having a positive refractive power, that is, a reduction lens 18. In this example, the ophthalmic lens 17 observes the fundus, and the reduction lens 18 adjusts the optical path 13 of the microscope to an intermediate image (not seen in this example) of the ophthalmic lens 17. Further, the positioning unit 11 includes a turning mechanism 19, by which the optical unit 12 can turn so as to exit from the optical path 13 or enter into the optical path 13. FIGS. 1 - 3, FIG. 5, and FIG. 6 show the positioning device 15 including the optical unit 12, which swings so as to enter into the optical path 13, and FIGS. 4, FIG. 7, and FIG. 8 show the positioning device 15 including the optical unit 12, which swings so as to exit from the optical path 13.

[0037] Furthermore, the positioning unit 11 can be coupled to the microscope by the connecting device 14. In this example, among other things, the connecting device 14 is composed of a housing 20 having a rail 21 and a clamping screw 22, and can be arranged on the objective lens of the microscope such that the objective lens is directly adjacent to the upper surface 23 of the connecting device 14.

[0038] The housing device 16 is made almost entirely of plastic and holds the ophthalmic lens 17. The housing device 16 is arranged in the positioning device 15. The positioning device 15 is made substantially of metal. In this example, by means of a pivoting mechanism 19 realized by a hinge 25, the lens barrel 24 of the positioning device 15 can be pivoted 90 degrees from a substantially vertical position along the optical path 13 so that there is no object in the middle of the optical path 13. The hinge 25 is realized using a guide 26, and the guide 26 enables the latch of the positioning device 15 at the respective positions shown in FIGS. 2 and 4. Thus, the positioning device 15 can be securely fixed at each position.

[0039] The housing device 16 is realized by a further lens barrel 27 which, in this example, consists of an upper part 28 and a lower part 29. Furthermore, a compression spring 30 is inserted into the upper part 28 and fixed by a ring 31 within the upper part 28. The ophthalmic lens 17 is held on the lower end 32 of the housing device 16. Furthermore, the lower part 29 is realized so as to have two protrusions 33, each of which passes through a longitudinal slot 34 within the upper part 28. The compression spring 30 is in contact with the upper edge 35 of the lower part 29, and the lower part 29 is at a step 37 on the lower end 38 of the upper part 28 with an annular shoulder 36. When the lower end 32 touches the eye, the lower part 29 can then be pushed into the upper part 28 against the spring force of the compression spring 30. Furthermore, when the housing device 16 has to be pivoted together with the positioning device 15, it is also possible to grasp the protrusions 33 by hand and push the lower part 29 into the upper part 28 in order to create a sufficient distance to the eye.

[0040] The receiving device 16 is realized by using a connecting element 39 that engages with and latches in a groove 40 within the lens barrel 27. The connecting element 39 is realized on a tab 41 at the upper end 42 of the upper part 28. The tab 41 enables the connecting element 39 to move along the optical path 13 by a spring-loaded attachment and can be actuated manually. Thereafter, it is possible to remove the receiving device 16 from the lens barrel 24 by pressing the tabs 41 together and / or turning them inwards.

[0041] The lens barrel 24 is substantially composed of an outer sleeve 43 and an inner sleeve 44. The inner sleeve 44 is rotatably mounted in a bearing 45 within the lens barrel 24. A mount 46 with a reduction lens 18 is inserted into the inner sleeve 44. Further, a helical hole 47 is realized in the inner sleeve 44 and a slot 48 is realized in the outer sleeve 43. Opposing protrusions 49 of the mount 46 pass through the helical hole 47 and the slot 48 respectively. By rotating the inner sleeve 44 relative to the outer sleeve 43, the mount 46 with the reduction lens 18 moves along the optical path 13. The position of the reduction lens 18 within the lens barrel 28 is visible to the user on the circumferential surface 50 of the lens barrel 24. In this example, the protrusion 49 is visible within the slot 48.

[0042] When using the observation device 10, the ophthalmic lens 17 can first be aligned with the eye by adjusting the height of the microscope. Thereafter, the reduction lens 18 can be set by adjusting its position within the lens barrel 24 so that the intermediate image of the ophthalmic lens 17 can be clearly focused by the microscope. The rotation of the inner sleeve 44 within the outer sleeve 43 is achieved by the drive unit 51 of the positioning device 15. In this example, the drive unit 51 is arranged in the connecting device 14 and includes a stepping motor 52, a belt drive 53, and a coupler 54. In this example, the drive wheel 55 of the belt drive 53 is connected to the output sleeve 57 within the connecting device 14 via a belt 56. The output sleeve 57 coaxially surrounds the optical path 13 and is rotatably mounted within the housing 59 of the connecting device 14 by a bearing 58. The coupler 54 is realized as a magnetic coupler 60, and the axial end face 61 of the inner sleeve 44 and the opposing axial end face 62 of the outer sleeve 57 each have magnets 63 embedded therein. The magnets 63 are arranged with alternating polarities so that torque can be transmitted to the inner sleeve 44 when the outer sleeve 57 rotates due to the opposing magnets 63 exerting magnetic force on each other.

[0043] The control device 64 of the positioning unit 11 is arranged within the housing 59, and the rotation of the lens barrel 24 and / or the rotation of the inner sleeve 44 can be controlled and detected by the control device. Even if the observation device 10 is turned or rotated manually on the microscope around the optical path 13, if the reduction lens 18 is adjusted and / or moved along the optical path 13 by this rotation, the stepping motor 52 can move the reduction lens 18 to the assumed position in the direction along the optical path 13. For this purpose, the control device 64 may be provided with a sensor (not shown in this example) for detecting rotation. Further, the control device 64 is provided with a power supply, a foot switch (not shown in this example), and a connection portion 65 for connecting to the microscope.

[0044] Figures 9 and 10 show the housing device 16 together with the cover unit 66 of the observation device 10. The cover unit 66 is made of a plastic material and is composed of an upper sterilization cover 67 and a lower sterilization cover 68. Using the upper sterilization cover 67, the end face 69 and the upper circumferential surface 70 of the lens barrel 24 can be covered. Using the lower sterilization cover 68, the circumferential surface 50 of the lens barrel 24 and a part of the hinge 25 can be covered. The upper sterilization cover 67 has a protrusion 71 that engages with an upper annular shoulder 72 formed on the lens barrel 24. Thus, the upper sterilization cover 67 can latch onto the upper annular shoulder 72. Further, a tab 73 for manually removing the upper sterilization cover 67 is provided on the upper sterilization cover 67. Further, a recess 74 is provided in the upper sterilization cover 67, and the pin 75 of the connection device 14 passes through the recess 74 at the attachment position. The pin 75 realizes a stopper 76 of the lens barrel 24 and a gap 77 between the lens barrel 24 and the connection device 14, and the circular covering area 78 of the upper sterilization cover 67 is accommodated in the gap 77 and is fixed by the pin 75 so as not to change its orientation.

[0045] Like the upper sterilization cover 67, the lower sterilization cover 68 is integrally formed and has a protrusion 79 that engages in an annular groove 80 at the lower part of the lens barrel 24. Thus, the lower sterilization cover 68 can be fixed to the lens barrel 24 by a latch. Further, a tab 81 is realized on the lower sterilization cover 68, where the lower sterilization cover 68 can be removed from the lens barrel 24 by the tab 81. The tab 81 is realized in the lower sterilization cover 68 with a cut line 82 so that an opening band 83 is formed, whereby when the tab 81 is manually actuated, the lower sterilization cover 68 is broken. Thus, after removal, it can be guaranteed that the cover unit 66 is not reused again. Further, the plastic material of the cover unit 66 is translucent.

[0046] Since the cover unit 66 completely covers the lens barrel 24, after the surgery, sterilization of the lens barrel 24 is not necessary. After the surgery, the cover unit 66 can be removed and replaced with a new sterilized cover unit 66 that has not yet been used. In the present application, this also applies to the housing device 16 having the ophthalmic lens 17 so as to prevent unintentional reuse and sterilization. Therefore, after the surgery, without requiring time-consuming sterilization of the observation device 10, by replacing the cover unit 66 and the housing device 16, the observation device 10 can be quickly prepared for the next surgery.

Claims

1. 1. An observation device (10) having a positioning unit (11) for positioning an optical unit (12) in an optical path (13) of a microscope between an objective lens of said microscope and the front of the eye to be observed, the positioning unit comprises a connection device (14), a positioning device (15), a receiving device (16), and the optical unit; The optical unit includes a lens for observing a fundus and a further optical element, the positioning unit comprises a pivoting mechanism (19), by means of which the optical unit can be pivoted out of and into the optical path; the positioning unit is connectable to the microscope by the connecting device; The lens is placed on the positioning device by the receiving device; said containment device being made at least in large part, preferably entirely, from a plastic material; The positioning device has a lens barrel (24) that is rotatably disposed on the rotation mechanism, The lens barrel is made at least in large part, or entirely, from metal. Observation equipment.

2. A further optical element is arranged below the pivoting mechanism (19). The observation device according to claim 1.

3. the further optical element is movable relative to the microscope in a direction along the optical path (13) by the positioning device (15).

3. The observation device according to claim 1 or 2.

4. The lens is an ophthalmic lens (17), the further optical element being at least one lens (18) having a positive refractive power and configured to adjust the optical path (13); The lens in the lens barrel (24) is arranged movably in a direction along the optical path under the rotating mechanism (19). The observation device according to any one of claims 1 to 3.

5. the observation device (10) is provided with a cover unit (66) made of a plastic material for covering the pivotable lens barrel (24) of the positioning device (15) in a sterile manner; The observation device according to any one of claims 1 to 4.

6. The cover unit (66) has an upper sterile cover (67) at least partially covering an end surface (69) of the lens barrel (24) and a lower sterile cover (68) at least partially covering a circumferential surface (70) of the lens barrel. The observation device according to claim 5.

7. the cover unit (66) is configured with at least one connecting element (71, 79) which must be broken when separating the cover unit from the positioning device (15); 7. The observation device according to claim 5 or 6.

8. the cover unit (66) has at least one tear strip (83) by means of which the cover unit is at least partially destructible; An observation device according to any one of claims 5 to 7.

9. the receiving device (16) is configured with at least one connecting element (39) which must be broken when separating the receiving device from the positioning device (15); An observation device according to any one of claims 1 to 8.

10. the receiving device (16) is configured with a further lens barrel (27), which is preferably conical in shape; An observation device according to any one of claims 1 to 9.

11. The further lens barrel (27) is made up of an upper part (28) and a lower part (29), the lower portion is loosely or spring-loaded attached to the upper portion such that the lower portion is insertable into the upper portion; The observation device according to claim 10.

12. At least one manually actuatable projection (33) is configured on said lower portion (29); the protrusion is movable through and along a longitudinal slot (34) defined in the upper portion (28); The observation device according to claim 11.

13. the positioning device (15) has a drive unit (51) by means of which the position of the further optical element can be set in a direction along the optical path (13); An observation device according to any one of claims 1 to 12.

14. the drive unit (51) is arranged on the connection device (14) above and / or below the pivot mechanism (19) on the lens barrel (24); The observation device according to claim 13.

15. The observation device (10) includes a shielding unit that shields an optical path of the positioning unit (11), The shielding unit is composed of at least one optically shielded, i.e. closed, lens barrel (24, 27), An observation device according to any one of claims 1 to 14.

16. The observation device (10) according to any one of claims 1 to 15, microscope.

17. A method of observing an eye using an observation device (10), comprising the steps of: an optical unit (12) is positioned by a positioning unit (11) of the observation device in the optical path (13) of the microscope between the objective lens of the microscope and the front of the eye to be observed, the positioning unit comprises a connection device (14), a positioning device (15), a receiving device (16), and the optical unit; The optical unit includes a lens for observing a fundus and a further optical element, the positioning unit comprises a pivoting mechanism (19), by which the optical unit is pivoted out of and into the optical path; the positioning unit is coupled to the microscope by the connection device; The lens is placed on the positioning device by the receiving device; said containment device being made at least in large part, preferably entirely, from a plastic material; The lens barrel (24) of the positioning device (15) is rotated, The lens barrel (24) is disposed on the rotating mechanism, The lens barrel is made at least in large part, or entirely, from metal. method.

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