Observation device and method for observing eye

Abstract

The invention relates to a viewing device and a method for viewing an eye. The observation device has a positioning unit for positioning the optical unit in the beam path of the microscope between the objective lens of the microscope and the front of the eye to be observed; the positioning unit comprises a connecting device, a positioning device, a receiving device and an optical unit, the optical unit comprises a lens for observing the fundus and a further optical element, the positioning unit comprises a pivoting mechanism, and the optical unit can be pivoted out of a beam path or into the beam path by means of the pivoting mechanism. The positioning unit can be coupled to the microscope by means of a connecting device, the lens is adapted to the positioning device by means of a receiving device, the receiving device is at least mainly made of plastic material, preferably completely made of plastic material, and the positioning device has a lens barrel which is arranged on a pivoting mechanism in a pivotable manner, the lens barrel is at least predominantly made of metal or completely made of metal.

Description

Field of the Invention

[0001] The present invention relates to an observation device having a positioning unit for positioning an optical unit in a beam path of a microscope between an objective lens of the microscope and the front of an eye to be observed. The positioning unit includes a connecting device, a positioning device, a receiving device, and the optical unit. The optical unit includes a lens for observing the fundus of the eye and another optical element. The positioning unit includes a pivoting mechanism by which the optical unit can be pivoted out of or into the beam path. The positioning unit can be coupled to the microscope by means of the connecting device, and the lens is adapted to the positioning device by means of the receiving device. In addition, the present invention relates to a method of observing an eye with such an observation device. The receiving device is at least mainly made of a plastic material, preferably completely made of a plastic material. In addition, the present invention relates to a method of observing an eye with such an observation device. Background Art

[0002] Microscopes for performing ophthalmic surgery are generally used for surgeries in the anterior region of the eye. If such interventions are also to be performed in the posterior region of the eye, an observation device capable of precisely focusing on this region of the eye needs to be added to the microscope. This type of observation device includes at least one wide-angle lens and / or an ophthalmoscope for wide-angle observation of the corresponding posterior part of the eye. The ophthalmoscope provides an intermediate image in the beam path in front of the objective lens of the microscope, and the intermediate image can be focused with the microscope. To focus the intermediate image, it is necessary to shorten the length of the beam path of the microscope, which can be performed by means of a corresponding setting mechanism on the microscope. However, since it is necessary to switch between different viewing angles with and without the ophthalmoscope during ophthalmic surgery, such a setting of the microscope is obstructive. Therefore, a so-called reduction lens can be provided in the beam path in front of the objective lens, and the reduction lens is used to shorten the beam path of the microscope and is used together with the ophthalmoscope. The two lenses are held by the positioning unit of the observation device as an optical unit. The positioning unit is directly fixed to the microscope and can be positioned in the beam path as needed, and the microscope basically does not need to be adjusted during the surgery. The positioning unit generally includes a connecting device by which the positioning unit can be coupled to the microscope. In addition, the positioning unit is designed such that the corresponding lens can be swung into or inserted into the beam path in a simple manner and removed from the beam path again.

[0003] For example, this type of observation device is known from DE 10 2011 002 940A1. In order to be able to adjust the intermediate image of the ophthalmoscope as precisely as possible to the focal length of the objective lens of the microscope, the ophthalmoscope is designed to be set along the beam path of the microscope by means of a screw drive.

[0004] The observation device is implemented such that the ophthalmoscope can be moved relative to the eye along the beam path. In this case, it is advantageous if the ophthalmoscope is as close as possible to the eye, because in this case a relatively large area of the eye is clearly visible. However, at the same time, contact between the ophthalmoscope and the eye must be avoided. Therefore, in order to obtain a clear image of as large an area of the eye as possible, it is always necessary to change the distance of the microscope relative to the eye and to coordinate this distance with the distance of the ophthalmoscope. If a certain procedural step during an ophthalmic surgical procedure requires a different distance from the ophthalmoscope to the eye, for example if the aqueous humor of the eye is to be aspirated, the adjustment of the corresponding relative distances from the ophthalmoscope to the microscope and to the eye and then the focusing of the obtained image must be performed again.

[0005] Now, it is considered advantageous if the observation device and / or the positioning unit is made of plastic and can be used as a disposable product, enabling the omission of its / their disinfection. Therefore, observation devices made of plastic and enabling single-use of the observation device are known. DE 10 2018 127469 B4 shows such an observation device.

[0006] However, in this case, it is disadvantageous that, unlike metal, plastic cannot always be used with the desired precision required for positioning the ophthalmoscope, especially in the case where the positioning device or the positioning unit is made of a fragile plastic rod. Therefore, when the ophthalmoscope swings into or out of the beam path, a displacement of the ophthalmoscope along the beam path or an offset transverse to the beam path can easily occur. Usually, subsequent correction of the position of the ophthalmoscope is required, which hinders the performance of ophthalmic surgery. Summary of the Invention

[0007] Therefore, an object of the present invention is to provide an observation device and method for observing the eye, which can improve the operation during an ophthalmic surgical procedure.

[0008] This object is achieved by an observation device, a microscope, and a method according to the present invention.

[0009] In the viewing device according to the invention, the viewing device has a positioning unit for positioning an optical unit in the following beam path of a microscope: the beam path is between the objective lens of the microscope and the front of the eye to be observed. The positioning unit includes a connecting device, a positioning device, a receiving device, and an optical unit. The optical unit includes a lens for observing the fundus and another optical element. The positioning unit includes a pivoting mechanism, and the optical unit can be pivoted out of the beam path or pivoted into the beam path by means of the pivoting mechanism. The positioning unit can be coupled to the microscope by means of the connecting device. The lens is adapted to the positioning unit by means of the receiving device. The receiving device is at least mainly made of plastic material, preferably completely made of plastic material. Wherein, the positioning device has a lens barrel pivotally arranged on the pivoting mechanism, and the lens barrel is at least mainly made of metal or completely made of metal.

[0010] The viewing device according to the invention can be adapted to a microscope and / or detachably connected to the microscope by means of the connecting device. In this case, the lens of the ophthalmoscope can be held in the following beam path of the objective lens: the beam path is between the eye to be observed and the objective lens. In this case, the aim is to arrange the lens such that the principal axis and / or optical axis of the objective lens of the microscope extends through the center point of the lens. By means of the pivoting mechanism, the optical unit having the lens and another optical element can be swung into the beam path or swung out of the beam path as needed during an ophthalmic operation. The said another optical element is preferably a lens with positive refractive power. In this case, how the pivoting mechanism is designed is initially irrelevant; what matters is that the optical unit can be completely removed from the beam path and moved into the beam path. Therefore, the pivoting mechanism can also be regarded as a displacement mechanism by means of which the optical unit can be displaced parallel to the beam path.

[0011] Furthermore, it is advantageous that the receiving device for holding the lens is substantially made of plastic material, and the lens barrel is substantially made of metal. Thus, the pivotable lens barrel can be designed in a particularly stable and precise manner and allows for an exact positioning of the lens and another optical element in the beam path, without the need for calibration adjustments as in the case of a pure disposable product. At the same time, due to the fact that the receiving device is made of plastic, the receiving device with the lens can be manufactured in a particularly cost-effective manner. It can be easily and mass-produced, for example, easily and mass-produced in the case of an injection molding process. This in turn makes it possible to use the receiving device as a disposable product. In this case, the receiving device can be discarded after an ophthalmic surgery has been performed. There is no need to disinfect the receiving device. For a subsequent ophthalmic surgery, a new receiving device that can be aseptically packaged can be used. The receiving device can be easily adapted to the lens barrel and / or detachably connected to the lens barrel.

[0012] Another optical element can be arranged below the pivot mechanism. Since the positioning device has a lens barrel pivotably arranged on the pivot mechanism, an arrangement of the other optical element in the lens barrel can be achieved. Thus, a movable arrangement of the other optical element within the lens barrel can be particularly easy. In this case, it is also possible to easily protect the other optical element from external influences.

[0013] Another optical element can be moved relative to the microscope in the longitudinal direction of the beam path by means of a positioning device. In this case, the movable arrangement of the other optical element below the pivoting mechanism enables the beam path of the microscope to be adjusted with the other optical element and / or the beam path to be shortened to the extent that the intermediate image of the lens can be focused. If the other optical element can be moved along the beam path below the pivoting mechanism, there is relatively more space available for moving the other optical element along the beam path compared to the case where the other optical element is arranged above the pivoting mechanism. In this case, the distance between the pivoting mechanism and the objective of the microscope is relatively short, since this is the only way to ensure that the optical unit and / or the positioning device can be completely removed from the beam path. The relatively large adjustment range of the other optical element enables the observation device to be adjusted generally for different types of microscopes and thus the observation device to be used for these different types of microscopes. In this case, there is no longer a need to design the other optical element separately for different microscopes with different beam paths. Additionally, the lens can also be kept fixed at a certain position in the beam path and does not have to be moved along the beam path relative to the microscope. It is only necessary to align the microscope together with the lens with the eye. In this case, the adjustment of the beam path can be simply performed by moving the other optical element. The lens and the other optical element can each comprise a plurality of optical components which are connected to one another and in each case together form an optical element. The lens can be an ophthalmoscope, and the other optical element is at least one lens having a positive refractive power and for adjusting the beam path, and the lens in the lens barrel is arranged below the pivoting mechanism in a manner capable of moving in the longitudinal direction of the beam path. The lens having a positive refractive power can be a so-called reduction lens, and the beam path of the microscope can be shortened by means of this reduction lens. Since the lens having a positive refractive power can move along the beam path in the lens barrel below the pivoting mechanism, the adjustment of the beam path can be easily performed with a relatively large adjustment range. The lens having a positive refractive power can be simply displaced along the beam path by means of a screw drive, a screw formed inside the lens barrel, etc. In this case, the lens barrel can be rotated at least in part. In this case, the lens having a positive refractive power can be accommodated in a support which can be displaced together with the lens inside the lens barrel.

[0014] The observation device may include a covering unit made of plastic material, which is used for aseptically covering the pivotable lens barrel of the positioning device. The covering unit may be implemented in a relatively thin-walled manner such that the covering unit can be in close contact with the pivotable lens barrel. The plastic material may be a rigid or flexible plastic material. In addition, the plastic material may be opaque or optically partially transparent. In particular, the covering unit may be configured such that the pivotable lens barrel is completely shielded from the environment by the covering unit on its outer surface. In this case, the pivotable lens barrel can be manually grasped and actuated by the surgeon without subsequent disinfection of the lens barrel. In this case, it is only necessary to remove the covering unit that can be manufactured cost-effectively from plastic material and replace it with a new sterile covering unit that has not been used so far.

[0015] The covering unit may have an upper sterile covering piece for at least partially covering the end surface of the lens barrel and a lower sterile covering piece for at least partially covering the circumferential surface of the lens barrel. Thus, the covering unit can be implemented in two parts. When the lens barrel pivots out of the light beam path, the upper sterile covering piece can be placed on the end surface of the lens barrel from above. The lower sterile covering piece can be placed on the lens barrel from below. In this case, the lens barrel is surrounded by the covering unit on all sides. In particular, when the surgeon manually grasps the lens barrel at the position where the lens barrel pivots out of the light beam path, the upper sterile covering piece allows protecting the end surface of the lens barrel from the touch of the surgeon. If the upper sterile covering piece is used, it is also advantageous to create a gap between the lens barrel and the connecting device, and the upper sterile covering piece can be positioned in this gap when the lens barrel swings into the light beam path.

[0016] The covering unit may be implemented with at least one connecting element that needs to be destroyed when the covering unit is separated from the positioning device. The connecting element may be implemented in the form of a latching element that engages with a protrusion implemented on the lens barrel or engages in a groove implemented on the lens barrel. A plurality of connecting elements may also be provided. The connecting element may be implemented or installed flexibly such that the connecting element can easily come into contact with the lens barrel. Importantly, the connecting element is configured such that the connecting element and / or the covering unit are destroyed when the covering unit is removed from the positioning device and / or the lens barrel. This prevents the covering unit from being reused incorrectly.

[0017] The covering unit may have at least one tear strip by means of which the covering unit can be at least partially destroyed. The tear strip may be implemented as having a tab that can be easily grasped manually. The tear strip may be implemented by a weakened line or two parallel weakened lines in the covering unit. If the covering unit is fixed to the positioning device and / or the lens barrel, for example, fixed to the positioning device and / or the lens barrel by means of a latch connection, the latch connection can be destroyed by manually actuating the tear strip. This makes it possible to easily remove the covering unit from the positioning device and / or the lens barrel.

[0018] The receiving device may be implemented with at least one connecting element that needs to be destroyed when separating the receiving device from the positioning device. This can also prevent the incorrect reuse of the receiving device after separation from the positioning device. For example, the connecting element may be implemented such that the connecting element is destroyed when the receiving device is removed from the positioning device.

[0019] The receiving device may be implemented to have another lens barrel, preferably a conical lens barrel. The other lens barrel may be directly attached to and fixedly connected to the lens barrel. The fixed connection may be achieved by, for example, a latch connection. It is particularly advantageous if the other lens barrel is implemented in a conical manner. In this case, the lens barrel can be adjusted to the shape of the light beam path such that at the lower end of the other lens barrel, the diameter of the other lens barrel is relatively small. In this case, the lens may be provided at the lower end. It is also advantageous if the other lens barrel is closed. In this case, the other lens barrel may be implemented as a conical sleeve.

[0020] The other lens barrel may include an upper section and a lower section, wherein the lower section may be loosely or spring-loadedly mounted on the upper section such that the lower section can be inserted into the upper section. The spring-loaded mounting may be achieved by means of a compression spring that is inserted into the upper section and the lower section can be moved into the upper section against the spring force of the compression spring. This can prevent the eyes from being undesirably damaged in the case where the lens and / or the lower section may come into contact with the eyes of the person to be operated on.

[0021] At least one manually actuable projection can be implemented on the lower section, where the projection can pass through a longitudinal slot implemented in the upper section and be able to move along the longitudinal slot. In this case, the surgeon can manually move the lower section in the direction of the beam path, that is, the surgeon grasps the projection and pulls the projection upward in the direction of the microscope, so that the lower section moves into the upper section. Advantageously, for this purpose, two opposite projections can also be implemented on the lower section, and the projections are respectively engaged into opposite longitudinal slots on the upper section. When the optical unit is to pivot out of the beam path, the surgeon can advantageously use the facility to manually move the lower section away from the eye in the direction of the beam path. In particular, if the lens is particularly close to the eye to be operated on, the lens can be manually moved out of the dangerous area for the eye, and the optical unit can pivot out of the beam path in the subsequent manual movement. This also applies to the reverse movement of the optical unit into the beam path. In this case, there is no longer a need for a corresponding movement of the microscope.

[0022] The positioning device can have a drive unit, and the position of another optical element can be set in the longitudinal direction of the beam path by means of the drive unit. The drive unit can be operated purely manually or also electrically. It is important that another optical element can be displaced and positioned along the beam path by means of the drive unit. In this regard, it is also advantageous if the drive unit is self-locking. If another optical element is arranged in the lens barrel, the drive unit can also be implemented at least partially or completely on the lens barrel.

[0023] The drive unit can be arranged on the connecting device above and / or below the pivoting mechanism on the lens barrel. Therefore, the drive unit can be arranged separately on the lens barrel, or it can also be implemented 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 advantageous to implement only a part of the drive unit on the lens barrel so that the surgeon is not obstructed by the protruding parts of the observation device during his / her work.

[0024] The observation device can include an occlusion unit for occluding the optical path of the positioning unit, where the occlusion unit can include at least one optically occluded or closed lens barrel. For example, the positioning device and the accommodating device can implement such a closed lens barrel. Advantageously, in this way, it is possible to avoid light sources, scattered light, etc. used during ophthalmic surgery from entering the beam path and affecting the representation of the eye image observed by the surgeon through the optical unit in an undesirable manner. Therefore, possible differences in terms of brightness, reflection, etc. can be avoided.

[0025] The drive unit may include a stepper motor, which may be coupled to the connector of the drive unit and the lens barrel via a belt drive or a transmission. In this case, the stepper motor may be an electric motor, and with this electric motor, a defined number of rotations can be performed until another optical element is in the desired position of the lens barrel. For this purpose, the lens barrel may be implemented to be rotatable in sections, so that the rotation of the stepper motor can be transmitted to the lens barrel via the belt drive and / or the transmission. The drive unit may include, for example, a sleeve located within the lens barrel, the sleeve being provided with threads or a helix and connected to the belt drive and / or the transmission via a connector. In this case, the rotation of the sleeve may cause another optical element to be raised or lowered and / or to move along the light beam path, and the sleeve may be moved by means of the stepper motor.

[0026] The connector can be separated or connected by means of a pivoting mechanism. This is particularly advantageous if the stepper motor with the belt drive or the transmission is arranged on the connecting device above the pivoting mechanism. In this case, the connector between the connecting device and the lens barrel can be implemented such that the connector is separated when the lens barrel pivots out of the light beam path, and the connector is connected when the lens barrel pivots into the light beam path. The connector can be implemented as a non-positive, form-fitting and / or friction connector.

[0027] It is advantageous if the connector is a magnetic connector including two annular members, which can transmit torque by means of magnets, wherein another optical element can be moved by means of the rotation of the lens barrel. The two coaxial annular members can each have a certain number of magnets, which exert magnetic forces on each other, so that the annular members attract each other and thus can transmit torque. The magnets can be arranged at regular intervals on the axial end faces of the respective annular members. The magnetic poles of the magnets of the respective annular members can be alternated such that the annular members are in a defined relative position when the connector is closed. It is particularly advantageous if a gap is provided between the annular members, because in this case the annular members and / or the connector do not have to contact each other to transmit torque. The gap can be used to insert a sterile cover into the connector and / or between the lens barrel and the connecting device.

[0028] The positioning unit may include a control device, wherein the control unit may be configured to detect the pivoting of the optical unit out of or into the beam path and transmit the detection situation to the microscope. The swinging in or out of the optical unit and / or the lens barrel can be easily detected by means of a sensor of the control device. In this case, the control device may signal to the microscope to indicate whether the optical unit is swung into the beam path or out of the beam path. If the microscope is equipped with a so-called inverter, the microscope can move the inverter into or out of the beam path within the microscope. In this case, beam transposition and mirroring of the intermediate image of the lens can be generated by means of the inverter, so that when the optical unit is swung into the beam path, an image of the eye arranged in the correct position is presented to the surgeon.

[0029] The positioning unit may include a control device, the rotation of the lens barrel can be detected by means of a sensor of the control device, and the drive unit can be controlled by means of the control device so that another optical element can be moved to a preset position along the longitudinal direction of the beam path by means of the drive unit. The sensor may be, for example, a Hall sensor provided on the drive unit and / or the lens barrel. Marks, a number of marks, may be arranged on the lens barrel in the form of a scale or the like, so that the rotation and position of another optical element in the longitudinal direction of the beam path can be detected by means of the sensor. Then, this enables the detection of the position of another optical element along the adjustment range. If, for example, an unintentional rotation of the lens barrel or the rotation of the connecting device on the microscope objective occurs when the optical unit and / or the lens barrel pivot out of the beam path, the other optical element is no longer in the preset position and / or no longer in the focus set by the surgeon before pivoting out when it pivots into the beam path. By means of the drive unit, the control unit can now move the optical element to the preset position and / or the previously set focus of the optical unit. In this case, the surgeon no longer needs to actuate the drive unit to correct the changed setting of the other optical element.

[0030] The microscope according to the invention includes the observation device according to the invention. Other advantageous embodiments of the microscope are provided by the description of the relevant features of the invention.

[0031] In a method of observing an eye with an observation device according to the present invention, an optical unit is positioned in the following beam path of a microscope by means of a positioning unit of the observation device: the beam path is between the objective lens of the microscope and the front of the eye to be observed. The positioning unit includes a connecting device, a positioning device, a receiving device, and an optical unit. The optical unit includes a lens for observing the fundus of the eye and another optical element. The positioning unit includes a pivoting mechanism, and the optical unit is pivoted out of the beam path or pivoted into the beam path by means of this pivoting mechanism. The positioning unit is connected to the microscope by means of the connecting device. The lens is adapted to the positioning unit by means of the receiving device. The receiving device is at least mainly made of plastic material, preferably completely made of plastic material. Among them, the lens barrel of the positioning device is pivoted, and the lens barrel is arranged on the pivoting mechanism and is at least mainly made of metal or completely made of metal. Regarding the advantages of the method according to the present invention, reference is made to the description of the advantages of the observation device according to the present invention.

[0032] The other optical element can be used to correct the refractive error of the eye. Since the other optical element allows the intermediate image of the lens to be focused and thus allows the beam path of the microscope to be adjusted, the refractive error of the eye can also be corrected with the other optical element.

[0033] Other advantageous embodiments of the method are provided by the description of the relevant features of the present invention. Description of the Drawings

[0034] Hereinafter, the preferred embodiments of the present invention will be explained in more detail with reference to the drawings.

[0035] In the figures:

[0036] Figure 1 A perspective view of the observation device is shown;

[0037] Figure 2 A side view of the observation device with an occlusion unit is shown;

[0038] Figure 3 A side view of the observation device without an occlusion unit is shown;

[0039] Figure 4 A side view of the observation device with a positioning device pivoted out of the beam path is shown;

[0040] Figure 5 A longitudinal sectional view of the observation device with an occlusion unit is shown;

[0041] Figure 6 A longitudinal sectional view of the observation device without an occlusion unit is shown;

[0042] Figure 7A perspective view of a viewing device with a positioning device for swinging out a beam path and a shielding unit is shown;

[0043] Figure 8 A perspective view of the viewing device without the shielding unit and the receiving device is shown;

[0044] Figure 9 A longitudinal cross-sectional view of the shielding unit and the receiving device is shown;

[0045] Figure 10 An exploded view of the shielding unit and the receiving device is shown. DETAILED DESCRIPTION

[0046] Figures 1 to 8 The combination shows an observation device 10 with a positioning unit 11, which is used to position an optical unit 12 in the beam path 13 of a microscope (not shown in greater detail in the present case). The observation device 10 can be adapted on a microscope between the objective of the microscope and the front face of the eye to be observed. The positioning unit 11 comprises a connecting device 14, a positioning device 15, a receiving device 16 and an optical unit 12. The optical unit 12 comprises an ophthalmoscope 17 and a lens or a reduction lens 18 with positive refractive power. In the present case, the ophthalmoscope 17 is used to observe the fundus, and the reduction lens 18 is used to adjust the beam path 13 of the microscope to an intermediate image of the ophthalmoscope 17 (not visible in the present case). In addition, the positioning unit 11 comprises a pivot mechanism 19, by means of which the optical unit 12 can be pivoted into the beam path 13 or pivoted out of the beam path 13. Figures 1 to 3 , Figure 5 and Figure 6 The positioning device 15 and the optical unit 12 are shown pivoted into the beam path 13, and Figure 4 , Figure 7 and Figure 8 A positioning device 15 with an optical unit 12 pivoted out of the beam path 13 is shown.

[0047] Furthermore, the positioning unit 11 can be coupled to a microscope by means of a connection device 14. In the present case, the connection device 14 comprises in particular a receptacle 20 with a rail 21 and a clamping screw 22 and can be fitted on the objective of the microscope such that the objective is directly adjacent to an upper side 23 of the connection device 14.

[0048] The receiving device 16 is made almost entirely of plastic and holds the ophthalmoscope 17. The receiving device 16 is adapted to the positioning device 15. The positioning device 15 is made substantially of metal. The lens barrel 24 of the positioning device 15 can be pivoted 90 degrees from a substantially vertical position in the light beam path 13 away from the light beam path 13 by means of a pivoting mechanism 19, which in the present case is realized by a hinge 25. The hinge 25 is provided with a guide 26 which allows the positioning device 15 to be latched in Figure 2 and Figure 4 the corresponding positions shown. Thus, the positioning device 15 can be fixed in the corresponding positions in a reliable manner.

[0049] In the present case, the receiving device 16 is realized by another lens barrel 27 which comprises an upper section 28 and a lower section 29. Furthermore, a compression spring 30 is inserted into the upper section 28 and fixed in the upper section 28 by means of an annular piece 31. The ophthalmoscope 17 is held on the lower end 32 of the receiving device 16. In addition, the lower section 29 is realized with two projections 33, each of the two projections 33 passing through a longitudinal slot 34 in the upper section 28. The compression spring 30 abuts against the upper edge 35 of the lower section 29, and the lower section 29 rests on a stepped portion 37 of a step 36 on the lower end 38 of the upper section 28. In the case where the lower end 32 abuts against the eye, the lower section 29 can now be pushed into the upper section 28 against the spring force of the compression spring 30. Furthermore, when the receiving device 16 pivots together with the positioning device 15, the projections 33 can also be grasped by hand and the lower section 29 can be pushed into the upper section 28 in order to form a sufficient distance relative to the eye.

[0050] The receiving device 16 is provided with a connecting element 39 which engages in a groove 40 in the lens barrel 27 and is latched in the groove 40 in the lens barrel 27. The connecting element 39 is realized on a tab 41 on the upper end 42 of the upper section 28. The tab 41 enables the connecting element 39 to be elastically mounted transversely to the light beam path 13 and can be actuated manually. Then, simultaneously pressing the tab 41 and / or externally rotating the tab 41 allows the receiving device 16 to be removed from the lens barrel 24.

[0051] The lens barrel 24 basically includes an outer sleeve 43 and an inner sleeve 44, and the inner sleeve 44 is rotatably mounted on a support 45 within the lens barrel 24. A support 46 having a reduction lens 18 is inserted into the inner sleeve 44. Additionally, a helix 47 is implemented in the inner sleeve 44, and a slot 48 is implemented in the outer sleeve 43. Opposite projections 49 on the support 46 each pass through the helix 47 and the slot 48. Rotation of the inner sleeve 44 relative to the outer sleeve 43 causes such movement of the support 46 having the reduction lens 18 along the light beam path 13. On the circumferential surface 50 of the lens barrel 24, the position of the reduction lens 18 in the lens barrel 28 is visible to the user. In the present case, the projections 49 are visible in the slot 48.

[0052] When using the viewing device 10, the ophthalmoscope 17 can first be aligned with the eye by adjusting the height of the microscope. Subsequently, the reduction lens 18 can be set by adjusting the position of the reduction lens 18 in the lens barrel 24 such that the intermediate image of the ophthalmoscope 17 can be clearly focused by means of the microscope. Rotation of the inner sleeve 44 within the outer sleeve 43 is effected by a drive unit 51 of the positioning device 15. In the present case, the drive unit 51 is provided on the connecting device 14 and includes a stepping motor 52, a belt drive 53, and a coupling 54. In the present case, a drive wheel 55 of the belt drive 53 is connected via a belt 56 to an output sleeve 57 within the connecting device 14. The output sleeve 57 coaxially surrounds the light beam path 13 and is rotatably mounted in a housing 59 of the connecting device 14 by means of a support 58. The coupling 54 is implemented as a magnetic coupling 60, and opposite axial end faces 61 of the inner sleeve 44 and 62 of the output sleeve 57 each have magnets 63 embedded therein. The magnets 63 are arranged in an alternating polarity manner such that the opposite magnets 63 exert a magnetic force on each other, so that torque can be transmitted to the inner sleeve 44 when the output sleeve 57 rotates.

[0053] A control device 64 of the positioning unit 11 is located within the housing 59, by means of which the rotation of the lens barrel 24 and / or the inner sleeve 44 can be controlled and detected. Thus, even if the viewing device 10 is rotated or turned about the light beam path 13 on the microscope, for example a manually performed rotation, if the reduction lens 18 is adjusted and / or moved along the light beam path 13 by this rotation, the reduction lens 18 can be brought to a predetermined position in the longitudinal direction of the light beam path 13 by means of the stepping motor 52. For this purpose, the control device 64 can be equipped with a sensor for detecting rotation (not shown in the present case). Additionally, a connector 65 for connection to a power supply, a foot switch (not shown in the present case), and the microscope is provided on the control device 64.

[0054] Figure 9 andFigure 10 The housing device 16 and the covering unit 66 of the observation device 10 are shown. The covering unit 66 is made of a plastic material and includes an upper sterile cover 67 and a lower sterile cover 68. With the upper sterile cover 67, the end surface 69 and the upper circumferential surface 70 of the lens barrel 24 can be covered. With the lower sterile cover 68, the circumferential surface 50 of the lens barrel 24 and a part of the hinge member 25 can be covered. The upper sterile cover 67 has a protrusion 71 that engages with an upper annular shoulder 72 formed on the lens barrel 24. Thus, the upper sterile cover 67 can be latched onto the upper annular shoulder 72. In addition, a tab 73 for manually removing the upper sterile cover 67 is provided on the upper sterile cover 67. Further, a recess 74 is formed in the upper sterile cover 67, and a pin 75 on the connecting device 14 passes through the recess 74 in the installed position. The pin 75 forms a stopper 76 of the lens barrel 24 and a gap 77 between the lens barrel 24 and the connecting device 14, and an annular covering area 78 of the upper sterile cover 67 is received in the gap 77 and fixed by the pin 75 to prevent rotation.

[0055] Like the upper sterile cover 67, the lower sterile cover 68 is integrally formed and has a protrusion 79 that engages with a lower annular groove 80 of the lens barrel 24. Thus, the lower sterile cover 68 can be fixed to the lens barrel 24 by latching. In addition, a tab 81 is formed on the lower sterile cover 68, and the lower sterile cover 68 can be removed from the lens barrel 24 by means of the tab 81. The tab 81 has a weakened line 82 formed in the lower cover 68, so that a tear strip 83 is formed, and when the tab 81 is manually actuated, the tear strip 83 causes the lower sterile cover 68 to be damaged. Thus, it can be ensured that the covering unit 66 will not be reused after removal. In addition, the plastic material of the covering unit 66 is partially transparent.

[0056] Since the covering unit 66 completely covers the lens barrel 24, it is not necessary to disinfect the lens barrel 24 after the operation has been performed. After the operation, the covering unit 66 can be removed and replaced with a new sterile covering unit 66 that has not been used. This also applies to the housing device 16 with the ophthalmoscope 17, so that unintentional reuse and disinfection are also excluded in this case. Thus, after the operation has been performed, the observation device 10 can be quickly prepared for a subsequent operation by replacing the covering unit 66 and the housing device 16, without the need to disinfect the observation device 10, which is time-consuming.

Claims

1. An observation device (10), the observation device (10) comprising a positioning unit (11), the positioning unit (11) being used to position an optical unit (12) in the following beam path (13) of a microscope: the beam path (13) is between the objective lens of the microscope and the front face of the eye to be observed, the positioning unit comprising a connecting device (14), a positioning device (15), a receiving device (16) and the optical unit, the optical unit comprising a lens for observing the fundus and another optical element, the positioning unit comprising a pivot mechanism (19), the optical unit being able to be pivoted out of the beam path or into the beam path by means of the pivot mechanism (19), the positioning unit being able to be connected to the microscope by means of the connecting device, the lens being adapted to the positioning device by means of the receiving device, the receiving device being at least predominantly made of plastic material, preferably completely made of plastic material, It is characterized in that The positioning device has a lens barrel (24) which is arranged on the pivot mechanism in a pivotable manner and is at least predominantly made of metal or completely made of metal.

2. The observation device according to claim 1, It is characterized in that The other optical element is arranged below the pivot mechanism (19).

3. The observation device according to claim 1 or 2, It is characterized in that The further optical element can be moved relative to the microscope in the longitudinal direction of the beam path (13) by means of the positioning device (15).

4. The viewing device according to any one of the preceding claims, It is characterized in that The lens is an ophthalmoscope (17), the other optical element is at least one lens (18) having positive refractive power and used to adjust the light beam path, and the lens in the lens barrel (24) is arranged below the pivot mechanism (19) in a manner that it can move along the longitudinal direction of the light beam path.

5. The viewing device according to any one of the preceding claims, It is characterized in that The viewing device (10) comprises a covering unit (66) made of plastic material, which is used for sterile covering of the pivotable lens barrel (24) of the positioning device (15).

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

7. The observation device according to claim 5 or 6, It is characterized in that The cover unit (66) is implemented with at least one connecting element (71, 79) which needs to be destroyed when separating the cover unit from the positioning device (15).

8. The observation device according to any one of claims 5 to 7, It is characterized in that The covering unit (66) has at least one tear strip (83) by means of which the covering unit can be at least partially destroyed.

9. The viewing device according to any one of the preceding claims, It is characterized in that The receiving device (16) is implemented with at least one connecting element (39) which needs to be destroyed when separating the receiving device from the positioning device (15).

10. The viewing device according to any one of the preceding claims, It is characterized in that The receiving device (16) is realized with a further lens barrel (27), preferably a conical lens barrel.

11. The observation device according to claim 10, It is characterized in that The further lens barrel (27) comprises an upper section (28) and a lower section (29), the lower section being loosely or spring-loadedly mounted on the upper section so that the lower section can be inserted into the upper section.

12. The observation device according to claim 11, It is characterized in that At least one manually actuatable projection (33) is implemented on the lower section (29), the projection passing through a longitudinal slot (34) implemented in the upper section (28) and being movable along the longitudinal slot.

13. The viewing device according to any one of the preceding claims, It is characterized in that The positioning device (15) has a drive unit (51), by means of which the position of the further optical element can be set in the longitudinal direction of the beam path (13).

14. The observation device according to claim 13, It is characterized in that The driving unit (51) is arranged on the connecting device (14) above the pivot mechanism (19) on the lens barrel (24) and / or below the pivot mechanism.

15. A viewing device according to any one of the preceding claims, It is characterized in that The observation device (10) comprises a shielding unit for shielding an optical path of the positioning unit (11), the shielding unit comprising at least one optically shielded or closed lens barrel (24, 27).

16. A microscope having a viewing device (10) according to any one of the preceding claims.

17. A method for observing an eye with an observation device (10), wherein an optical unit (12) is positioned in the following beam path (13) of a microscope by means of a positioning unit (11) of the observation device: the beam path (13) is between the objective lens of the microscope and the front of the eye to be observed, the positioning unit comprising a connecting device (14), a positioning device (15), a receiving device (16) and the optical unit, the optical unit comprising a lens for observing the fundus and another optical element, the positioning unit comprising a pivoting mechanism (19), the optical unit being pivoted out of the beam path or into the beam path by means of the pivoting mechanism (19), the positioning unit being connected to the microscope by means of the connecting device, the lens being adapted to the positioning device by means of the receiving device, the receiving device being at least predominantly made of plastic material, preferably completely made of plastic material, It is characterized in that The lens barrel (24) of the positioning device (15) is pivotable, the lens barrel (24) is arranged on the pivot mechanism, and the lens barrel is at least mainly made of metal or completely made of metal.

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