Safety device for a laser microscope, and laser microscope having a safety device of this type

Abstract

The invention relates to a safety device for a laser microscope comprising an optical unit (100), which has: a laser objective (26); a laser light source (21); a laser optical assembly (27); a sample receptacle (12) for receiving a preparation and / or a sample holder; and an access opening (14) for loading the sample receptacle (12) with the preparation and / or the sample holder, wherein the access opening (14) is offset to the laser objective (26) such that a laser beam (LS) emitted by the laser objective (26) is reflected and / or scattered and / or absorbed within the optical unit (100), and wherein the sample receptacle (12) comprises a movement apparatus (13) which can be moved from a loading position in which the sample receptacle (12) is accessible via the access opening (14) into an analysis position in which the sample receptacle (12) is arranged such that a laser beam (LS) emitted by the laser objective (26) hits the preparation and / or the sample holder.

Description

[0001] Safety device for a laser microscope and laser microscope with such a safety device

[0002] The invention relates to a safety device for a laser microscope and a laser microscope with such a safety device.

[0003] Light microscopes are commonly used to analyze biological tissue specimens, and in special applications, laser scanning microscopes are used. Multiphoton microscopes have proven particularly useful in this regard. One such multiphoton microscope is known, for example, from US Pat. No. 6,356,088 B1.

[0004] Multiphoton microscopy, or laser scanning microscopy in general, often uses pulsed lasers with high peak power. These high peak powers can pose a danger to the user. In particular, damage to the retina of a user's eye or even skin burns can occur. This danger is particularly evident because laser light with a wavelength in the non-visible spectrum is usually used, which is why the blink reflex is not functioning.

[0005] In practice, it is therefore common for users of such laser scanning microscopes to take special safety precautions. This includes wearing laser safety goggles that absorb the wavelength of the laser used. Furthermore, such microscopes are often elaborately enclosed to prevent laser light from escaping, with additional switch devices used to deactivate the laser light source in certain situations, for example, when a housing is opened.

[0006] All of these previously known methods for increasing the safety of laser scanning microscope operation are complex and significantly limit the user-friendliness of the laser scanning microscope. In particular, the use of additional switches increases the manufacturing costs of such a laser scanning microscope. US 2010 / 0 208 053 ​​A1 discloses a microscope in which a light beam from an LED is directed from above onto a specimen via deflection optics. The deflection optics are arranged beneath a housing cover having a top wall and several side walls which, when the housing cover is closed, completely enclose the deflection optics and the specimen. When the housing cover is open, the deflection optics are freely accessible from all sides, so that light emerging at an angle or light reflected from a base surface of the microscope can reach the microscope operators.

[0007] WO 2019 / 165480 A1 describes an inverted microscope in which, unlike the setup according to US 2010 / 0208053 A1, the specimen is illuminated from below. Operators are therefore directly exposed to the emitted light unless the existing lid is manually closed. While this can be coupled to a light source interruption device, this results in a more complex device design and a potential source of error. Similar microscopes are described in EP 3060954 B1 and US 2008 / 0247038 A1. All of these inverted microscopes carry the risk that operators may open the lid during operation, allowing a direct view into the microscope light beam path. This can be hazardous to health when using laser light.

[0008] DE 20 2004 021 104 U1 describes a laser microscope with a protective device to prevent eye damage caused by laser light. The protective device is essentially transparent, but impermeable to harmful radiation components. This allows an operator to view the sample in the microscope without risk of eye damage. Due to the light permeability of the protective device, the measurement performed with the microscope can be distorted. Furthermore, aging of the material used for the protective device can lead to a change in the transmission behavior. Adequate protection is therefore not permanently guaranteed. Furthermore, this known laser microscope does not include a movement device that allows the sample to be moved between a loading and an analysis position, which complicates operation.The object of the invention is therefore to provide a safety device for a laser microscope that can be manufactured with minimal technical effort and, in particular, can be integrated into a laser microscope. Furthermore, the safety device should not significantly limit the user comfort of the laser microscope. A further object of the invention is to provide a laser microscope with such a safety device.

[0009] According to the invention, this object is achieved with regard to the safety device by the subject matter of patent claim 1 and with regard to the laser microscope by the subject matter of patent claim 14.

[0010] The invention is based on the idea of ​​specifying a safety device for a laser microscope with an optical unit comprising a laser objective, a laser light source, laser optics, a sample holder for receiving a specimen and / or a sample holder, and an access opening for loading the specimen and / or the sample holder into the sample holder. The access opening is arranged offset from the laser objective such that a laser beam emitted by the laser objective is reflected and / or scattered and / or absorbed within the optical unit. The sample holder also comprises a movement apparatus that can be moved from a loading position to an analysis position. In the loading position, the movement apparatus is accessible via the access opening. In the analysis position, the sample holder is arranged such that a laser beam emitted by the laser objective strikes the specimen and / or the sample holder.

[0011] The offset arrangement of the access opening to the laser objective ensures in a simple and efficient manner that laser light cannot escape from the optical unit. This significantly reduces the risk of injury to the user. In contrast to previously known laser microscopes, in which the laser objective is directly visible to the user, the specimen and / or sample holder is inserted into the sample holder in the invention in an area that is spatially separated from the laser objective. This means that there is no risk of injury to the user, even when the laser light is activated. After the specimen and / or sample holder have been inserted into the sample holder, the sample holder is moved into the analysis position by means of the movement apparatus, with the specimen or sample holder then being positioned in an area that can be detected by the laser beam of the laser objective.

[0012] The safety device according to the invention is particularly easy to implement technically and, due to its simple design, cost-effective. In particular, a commercially available microscope lens can be used as the laser lens, which saves costs.

[0013] Furthermore, it is particularly reliable in terms of safety. A further advantage of the safety device according to the invention is that it hardly compromises user comfort when operating a laser microscope. In particular, inserting the specimen or a sample holder into the sample holder is essentially the same as with previously known laser microscopes.

[0014] In general, the sample holder can be designed so that a specimen, for example a tissue sample, can be placed directly into the sample holder. Alternatively, and due to its ease of use, it is preferred if the specimen is placed in a sample holder outside the safety device, in particular outside the laser microscope, and the sample holder is then arranged, in particular temporarily fixed, in the sample holder. The sample holder can be fastened in or to the sample holder, in particular by clamping and / or form-fitting and / or magnetically. It is also possible to hold the sample holder in or to the sample holder pneumatically, in particular by means of a vacuum.

[0015] In a preferred embodiment of the safety device according to the invention, the optical unit is divided by a partition into a sample housing and a preferably light-tight laser housing. The laser housing is preferably adapted to accommodate the laser light source and / or the laser optics. In particular, detectors for detecting fluorescent light can be arranged in the laser housing. The light-tight laser housing prevents the unwanted escape of laser radiation and thus offers additional protection for a user. At the same time, the light-tight laser housing prevents the entry of stray light, which could impair the light-sensitive detectors and lead to a falsification of the measurement results. This achieves high measurement accuracy and reliability of the detectors while simultaneously ensuring high user safety.

[0016] According to the invention, the access opening is provided in an outer wall of the optical unit. The outer wall is arranged opposite the laser objective. In particular, the access opening and the laser objective can be arranged in mutually parallel planes and offset from one another. The offset arrangement advantageously ensures that a laser beam emitted by the laser objective is directed towards the outer wall and cannot exit the optical unit through the access opening. It is also possible for the laser beam to strike an area of ​​the musculoskeletal system or the sample holder. The laser objective is preferably arranged such that the emitted laser beam is mainly perpendicular to the partition wall or outer wall. In any case, the laser beam is reflected and / or scattered and / or absorbed within the optical unit in such a way that it cannot exit the optical unit via the offset access opening.

[0017] In this context, it should be noted that the laser beam introduced into the laser lens is expanded by the laser lens. The light emitted by the laser lens is therefore highly divergent and does not emerge in the focused form typical for a laser beam. For the purposes of this application, the light emitted by the laser lens is nevertheless referred to as a laser beam to indicate that it is the same light as the laser beam that is coupled into the laser lens in focused form.

[0018] The access opening can also be closed with a lid. The lid provides an additional safety barrier, not only for the entry or exit of light, but particularly as a mechanical barrier to protect a user. The movement apparatus, which is moved after a specimen and / or a sample holder has been inserted into the sample holder, represents a potential mechanical hazard for a user. In particular, a user's finger can be crushed, for example, when moving the movement apparatus. To ensure mechanical safety here, a lid can be provided that is closed before the sample holder is moved by the movement apparatus from the loading position to the analysis position. The lid can, for example, be closed manually, with a closing switch or closing sensor being provided that informs a control system when the lid is closed.Only then is the movement of the musculoskeletal system released.

[0019] It can also be provided that the lid is formed by a closing section of the musculoskeletal system. This eliminates the need for an additional component, namely a separate lid, which reduces the manufacturing costs of the safety device. Such a design of the lid by the closing section of the musculoskeletal system also reduces the risk of injury to a user when the musculoskeletal system is moved from the analysis position to the assembly position. Additionally, it can also be provided that the lid and / or the musculoskeletal system is secured by means of a force sensor or torque sensor and a corresponding control system, so that the movement of the lid and / or the musculoskeletal system is stopped when a predetermined resistance value is exceeded. This allows a blockage of the movement to be detected and the movement to be stopped as a result.For this purpose, the lid and / or the movement apparatus are preferably electrically connected to a corresponding control system.

[0020] The movement apparatus can generally comprise a light-permeable receiving area and an opaque cover area for covering the laser lens in the loading position. The light-permeable receiving area is preferably permeable to laser light, in particular to infrared laser light, so that the specimen arranged in the receiving area can be easily scanned by a laser beam. If the sample holder is configured so that a specimen can be placed directly into the sample holder, the light-permeable receiving area is preferably designed as a laser-transparent glass plate of the sample holder. If the sample holder serves to accommodate a sample holder, the receiving area can be formed by a through-opening or a laser-transparent glass plate. The sample holder generally has a laser-transparent glass plate onto which a specimen can be arranged.In particular, the sample holder can be used both to accommodate a sample holder and to directly hold a specimen. This makes the sample holder universally applicable.

[0021] The opaque cover area is preferably positioned so that it covers the laser lens in the loading position. The opaque cover area essentially acts as a beam interrupter, further ensuring that the laser beam does not leave the optical unit. The translucent receiving area, on the other hand, is preferably positioned directly above the laser lens in the analysis position, so that the laser beam emitted by the laser lens strikes the specimen arranged in the translucent receiving area.

[0022] In principle, it is conceivable for the movement apparatus to be moved manually from the assembly position to the analysis position and vice versa. However, it is preferred if this movement is motorized, i.e. the movement apparatus is motorized. The movement apparatus can be coupled to a corresponding control system so that movement of the movement apparatus is linked to previously defined conditions. One condition can be, for example, that the cover of the access opening is closed. A further condition can be that movement from the analysis position to the assembly position is only possible if the laser light source is switched off or the laser beam is interrupted within the laser housing. Such conditions thus provide an additional safety precaution to prevent a user from being exposed to the laser beam.

[0023] The movement apparatus can, in particular, be movable linearly and / or in a plane. The plane preferably runs orthogonally to the beam direction of the laser beam emitted by the laser objective. Essentially, the movement apparatus can be designed as a movement table. The movement table can comprise the light-permeable receiving area. Preferably, the movement table is movable or displaceable such that the light-permeable receiving area is arranged above the laser objective in the analysis position and below the access opening in the loading position. The safety device according to the invention, in particular the optical unit, has laser optics that can be arranged between the laser light source and the laser objective. The laser optics preferably comprise at least one deflection mirror, at least one optical lens arrangement, at least one beam deflection unit, and / or at least one optical filter.The laser optics can be arranged together with the laser light source within the laser housing. The at least one optical lens arrangement serves to expand and / or focus the laser beam.

[0024] Scanning of the specimen can be achieved via the beam deflection unit. The beam deflection unit can, for example, comprise at least one movable deflection mirror. The beam deflection unit, in particular the movable deflection mirror, can have a galvanometric drive. The point of incidence of the laser beam on the specimen is thus influenced by rotating and / or pivoting the scanning mirrors.

[0025] Using an optical filter, it is possible to filter out specific wavelengths from the laser beam to increase image contrast. The optical filter preferably also serves as a beam splitter, directing reflected fluorescent light to detectors in the optical unit. The advantage of a deflection mirror is that it allows for a particularly compact design of the safety device. In particular, the laser light source can be aligned horizontally, for example, with the light beam being deflected in a vertical direction by the deflection mirror.

[0026] In a preferred variant of the safety device, a laser interruption device for interrupting the laser beam is provided between the laser light source and the laser lens. The laser interruption device provides additional safety by actively interrupting the laser beam.

[0027] The laser interruption device is preferably coupled to a controller adapted to interrupt the emission of the laser beam by means of the laser interruption device when the musculoskeletal system is outside the analysis position and / or the optical unit, in particular the cover and / or an outer housing of the optical unit, is open. The laser interruption device thus constitutes a further safety precaution, ensuring, for example, that laser light cannot pose a danger to a user even in the event of damage to a housing of the laser microscope.

[0028] For this purpose, the laser interruption device can comprise, for example, a shutter arranged in the beam path, a beam deflection unit, and / or a switch for deactivating the laser light source and / or the musculoskeletal system. A shutter arranged in the beam path of the laser beam can be activated, for example, when the musculoskeletal system is outside the analysis position and / or damage to an outer housing of the optical unit is detected. The shutter then interrupts the laser beam, preventing it from reaching exposed areas of the laser microscope. Such a shutter is preferably arranged within the laser housing of the safety device.

[0029] A beam deflection unit, in particular a scanning mirror, can be controlled by the controller to deflect the laser beam to such an extent that it no longer passes through the laser lens into the sample receiving area. Such a laser interruption device essentially functions similarly to a shutter, whereby the laser beam is not completely interrupted but merely deflected into an area where it is absorbed within the optical unit. In principle, it is also possible to deactivate the beam deflection unit.

[0030] The laser interruption device can further comprise a switch or sensor for deactivating the laser light source and / or the musculoskeletal system. Such a switch, specifically a locking switch, can be connected, for example, to the cover of the safety device. A controller, which has a signal connection to the locking switch, can be configured, for example, to deactivate the laser light source when the cover's locking switch is open. Alternatively or additionally, further switches can be arranged on an outer housing of the optical unit so that an opening of the outer housing, for example due to damage, is detected. As soon as such an opening is detected by the corresponding switch, the laser light source can also be electrically deactivated, in particular by means of the controller.Alternatively or additionally, it can also be provided that if an open switch, in particular a locking switch or housing switch, is detected, the movement of the musculoskeletal system is interrupted. In particular, the musculoskeletal system can be deactivated to prevent another specimen from being inserted into the sample holder.

[0031] It is also possible for the laser interruption device to have an electronic interlock. This can be provided in addition to an on / off switch and / or emergency stop switch and / or the locking switch described above. The interlock device can, in particular, be a potential-free contact which, in the event of an interruption, leads to the switching off of the laser light source.

[0032] The sample holder, in particular the translucent receiving area, can be positioned in the analysis position between the laser objective and the specimen and / or the sample holder. The translucent receiving area can be formed, for example, by translucent glass or another laser-transparent material. Alternatively, the translucent receiving area can be formed by a through-opening or a recess. The translucent receiving area thus makes it possible to arrange the specimen directly or indirectly via a sample holder in its predetermined plane, which remains constant with respect to the distance from the laser objective. This enables particularly good scanning of different specimens with consistent quality. At the same time, the specimen and / or sample holder are inserted into the sample holder from a side opposite the laser objective, which is advantageous for handling the specimen or sample holder.

[0033] By locating the sample holder, particularly the translucent receiving area, between the laser lens and the specimen or sample holder, users are prevented from accessing the laser lens and contaminating it through contact. The design of the sample holder thus prevents damage to or impairment of the laser lens's performance.

[0034] In preferred embodiments of the invention, the laser light source may comprise a fiber laser, in particular an ytterbium-doped fiber laser. It has been shown that such a laser is particularly well suited for the histological examination of tissue specimens and delivers high-quality results. In particular, the laser light source may be designed to generate a pulsed laser beam. The laser light source is preferably a femtosecond laser.

[0035] A secondary aspect of the invention relates to a laser microscope, in particular for the histological examination of tissue preparations, with a safety device as described above.

[0036] The advantages and preferred developments mentioned in connection with the safety device also apply accordingly to the laser microscope according to the invention.

[0037] The laser microscope is particularly preferably designed as an inverted laser microscope. Alternatively or additionally, it can be designed as a multiphoton microscope.

[0038] It is particularly preferred if the laser microscope is configured as an inverted multiphoton microscope.

[0039] An inverted laser microscope offers a wide range of options, particularly with regard to working distances and specimen sizes. Tissue specimens, in particular, are easier to observe with an inverted microscope, as cells in such specimens sink to the specimen holder and adhere to it.

[0040] In addition, the distance between the specimen and the laser lens is constant. This shortens the observation time for multiple specimens, especially when placed one after the other in the sample holder, since the focus of the laser beam remains the same for all subsequent specimens.

[0041] The invention will be explained in more detail below using an exemplary embodiment with reference to the attached schematic drawings.

[0042] Fig. 1 is a schematic cross-sectional view of a safety device according to the invention according to a preferred embodiment, wherein the movement apparatus is in the loading position; and Fig. 2 is a schematic cross-sectional view of the safety device according to Fig. 1, wherein the movement apparatus is in the analysis position.

[0043] Fig. 1 shows a schematic representation of a safety device with an optical unit 100. The optical unit 100 can be light-tight and preferably comprises an outer housing 40 with an opening 41 through which a specimen or a sample holder for a specimen can be inserted into the optical unit 100. The specimen can, in particular, be a biological tissue specimen for histological examination.

[0044] In the illustrated embodiment, the safety device comprises at least one sample housing 10, which is sealed light-tight with the exception of a light feedthrough for a laser beam LS and an access opening 14 for receiving a specimen or sample holder. In particular, feedthroughs for cables 28 are also sealed light-tight. Furthermore, an objective opening 11 for a laser objective 26 is provided. The objective opening 11 can have a diaphragm that forms a light-tight seal against the laser objective 26. The diaphragm can be flexible in order to follow a focusing movement of the laser objective 26. The laser objective 26 is preferably movably mounted and, in particular, motorized to enable focusing of the laser beam LS onto the specimen.

[0045] In the exemplary embodiment according to the accompanying drawings, the sample housing 10 is connected to a laser housing 20. The sample housing 10 has, in particular, a partition wall 15 that separates the sample housing 10 from the laser housing 20. Opposite the partition wall 15 is an outer wall 16 of the sample housing 10, in which the access opening 14 is arranged. The outer wall 16 preferably extends parallel to the partition wall 15. In particular, the outer wall 16 is oriented orthogonally to a beam direction of the laser beam LS emitted by the laser objective 26.

[0046] It is also possible for the optical unit 100 to have a single housing. A division into the sample housing 10 and the laser housing 20 is not mandatory. However, it is essential that the access opening 14 and the laser lens 26 are offset from one another such that the laser lens 26 is not directly visible to a user.

[0047] The sample housing 10 has a sample receptacle 12 suitable for receiving a specimen or a sample holder. It is preferred to use a sample holder into which a specimen, for example, a tissue specimen, is inserted. The sample holder can have a laser-transparent base. The sample receptacle 12 preferably has means for securing the sample holder. In particular, the sample holder can be connected to the sample receptacle 12 in a clamping and / or form-fitting manner and / or magnetically.

[0048] The sample holder 12 can, in particular, have a movement device 13, which in the embodiment shown here is designed, in particular, as a traversing stage. The movement device 13 is arranged within the optical unit 100, in particular within the sample housing 10, for linear movement. The movement device 13 can, in particular, be controlled by a motor, i.e., can be moved in a motorized manner.

[0049] The musculoskeletal system 13 or the sample holder 12 preferably comprises a receiving area 13a that is translucent or laser-transparent, in particular translucent to infrared light. Specifically, the receiving area 13a can have a laser-transparent specimen plate, in particular a glass plate, onto which a specimen can be placed directly. It is preferred if the receiving area 13a is formed by a through-opening or has a through-opening. For example, a sample holder that includes a laser-transparent base or is laser-transparent can be placed and optionally secured onto the through-opening. The base of the sample holder is preferably also transparent to fluorescent light, in particular eosin, as well as to second-order or higher-order harmonic light, in particular SHG light or THG light.

[0050] The receiving area 13a is delimited by two side walls 13c, which essentially bridge the distance between the access opening 14 and the receiving area 13a. In the loading position of the movement apparatus 13, which is shown in Fig. 1, the side walls 13c essentially form a mechanical barrier, preventing a user from reaching into the sample housing 10. Rather, only access to the receiving area 13a is possible.

[0051] A cover region 13b of the movement apparatus 13 extends from at least one of the side walls 13c, extending essentially horizontally. The cover region 13c is oriented toward the lens mount 11 or the laser lens 26, such that the cover region 13b covers the laser lens 26 when the movement apparatus 13 is in the loading position. This state is illustrated in Fig. 1. Thus, the laser beam LS, if activated, strikes the cover region 13b and is reflected or absorbed there, ensuring that the laser beam LS cannot exit the sample housing 10 via the access opening 14.

[0052] The cover area 13b is generally optional and, in particular, not required as a safety feature of the safety device according to the invention. Rather, laser safety for users is achieved by arranging the laser lens 26 opposite the closed outer wall 16 of the optical unit 100. Consequently, the laser lens 26 is not directly visible, and a laser beam LS emitted by the laser lens 26 strikes the outer wall 16, so that people are not directly exposed to the laser beam LS.

[0053] In Figs. 1 and 2, it is clearly visible that the access opening 14 is offset from the lens holder 11 or the laser lens 26. A laser beam LS emitted by the laser lens 26 therefore impinges on an area of ​​the sample housing 10 that is closed to the outside. In any case, the offset arrangement of the access opening 14 and the lens holder 11 or the laser lens 26 ensures that the laser beam LS cannot leave the sample housing 10.

[0054] The laser housing 20 is preferably designed to be light-tight, with all passages in its housing walls also being sealed light-tight. This particularly applies to passages for cables 28 or a laser connection 29, as well as the passage for the laser lens 26. The passage for the laser lens 26 is essentially formed by the lens holder 11, which is located in the partition wall 15. The lens holder 11 can comprise a diaphragm that forms a light-tight seal against the laser lens 26. The light-tight closure of the laser housing 20 ensures that laser light LS remains in the laser housing 20 unless it can escape via the laser lens 26.

[0055] A laser light source 21 is arranged in the laser housing 20, which generates the laser beam LS (Fig. 2). The laser beam LS reaches a deflection mirror 22, which deflects the laser beam LS from a horizontal direction to a vertical direction. It is also conceivable to dispense with the deflection mirror 22, particularly if the laser light source 21 is configured such that the laser beam LS is directed toward the laser objective 26, in particular pointing upwards.

[0056] From the deflection mirror 22, the laser beam LS travels to a first lens arrangement 23a, which is preferably designed as a telescope. A telescope is an arrangement of at least two lenses that cause the laser beam LS to expand, shrink, or focus.

[0057] The expanded laser beam LS is then directed onto a beam deflection unit 24, in particular one or more scanning mirrors. The scanning mirror preferably has a galvanometric drive or a galvanometer, with which the angular orientation of the scanning mirror can be changed in order to scan the laser beam LS across a specimen. Furthermore, a resonant scanner can be used, or one of the scanning mirrors can be designed as such. The resonant scanner comprises a mirror and several magnets, which are jointly arranged on a torsion spring, which is specifically oscillated by the magnets.

[0058] From the beam deflection unit 24, the laser beam LS passes to a second lens arrangement 23b. The second lens arrangement 23b serves to correctly direct the laser beam LS onto the laser lens 26 during the scanning movement, which is adjusted by the beam deflection unit 24, in particular to expand the laser beam 26.

[0059] Between the second lens arrangement 23b and the laser objective 26, the laser beam LS passes through an optical filter 25, which filters out unwanted wavelength components and, in particular, redirects the fluorescent light and / or higher harmonic light, particularly SHG light and / or THG light, reflected from the specimen toward detectors not shown here. The optical filter 25 thus forms a beam splitter. The laser light LS originating from the laser light source 21 passes through the optical filter largely unchanged.

[0060] From the filter 25, the laser beam LS reaches the laser lens 26, which directs the laser beam LS into the sample housing 10 and focuses it onto the specimen. The lenses 23, scanning mirror 24, and the filter 25 together form a laser optics system 27, which is arranged between the laser light source 21 and the laser lens 26.

[0061] Fluorescent light is reflected from the specimen into the laser lens 26 and reaches the optical filter 25 in a direction opposite to the laser beam LS. The fluorescent light has a different wavelength than the laser light LS, is deflected by the optical filter 25, and directed to the detectors. The detectors capture the fluorescent light and convert it into electrical signals, which are combined into an image via an image processing module. The image can then be output via an optical display.

[0062] As can be clearly seen in Fig. 2, the laser beam LS reaches the specimen from below via the laser objective 26, which is located in the receiving area 13a, in particular in the sample holder 12, of the musculoskeletal system 13. In this respect, the laser microscope shown is an inverted laser microscope, preferably in the form of a multiphoton microscope.

[0063] The safety device of the laser microscope, which is primarily formed by the optical unit 100, in particular the sample housing 10 and the offset arrangement of the access opening 14 and the laser objective 26, can additionally be equipped with a cover 30. The cover 30 makes it possible to close the access opening 14 in order to prevent a user from reaching into the interior of the sample housing 10 when moving the musculoskeletal system 13. This provides mechanical protection, in particular to prevent crushing or other injuries to the user caused by moving the musculoskeletal system 13. The safety device can comprise further elements that increase safety for a user. In particular, a laser interruption device can be provided which interrupts the laser beam LS in predetermined operating states or based on predetermined conditions.For example, the laser interruption device can be connected to a locking switch 31 that interacts with the cover 30 and detects a closed state of the cover 30. In the state of the safety device according to Fig. 2, for example, the cover 30 is closed, thus activating the locking switch 31. The cover 30 can additionally be locked or secured by means of a locking mechanism 34.

[0064] The shutter switch 31 is connected to a controller 33, which detects the open state of the lid 30 and subsequently activates the laser interruption device. In addition to the shutter switch 31 on the lid 30, additional shutter switches 31 can be arranged, for example, on the outer housing 40 of the laser microscope. These additional shutter switches 31 can be opened if the outer housing 40 is damaged or opened. If one of the shutter switches 31 is opened, the controller 33 receives a corresponding signal and activates the laser interruption device.

[0065] The laser interruption device can be a switch that, for example, interrupts a current or voltage supply to the laser light source 21. Alternatively, the controller 33 can control a shutter 32 arranged in the beam path of the laser beam LS, preferably between the laser light source 21 and the laser lens 26, which is closed as soon as the controller 33 receives a signal from the shutter switch 31, after which the cover 30 is opened.

[0066] Alternatively or additionally, the laser interruption device can also comprise the beam deflection unit 24, in particular the scanning mirror. The beam deflection unit 24 or the scanning mirror can be pivoted or rotated such that the laser beam LS no longer reaches the laser objective 26, but is, for example, absorbed, reflected, or scattered within the laser housing 20. This also prevents the laser beam LS from escaping via the laser objective 26, in particular into the sample housing 10, when one of the shutter switches 31 is open. Corresponding cables 28, which can transmit control commands, connect the controller 33 to the individual components of a laser interruption device, in particular to the laser light source 21, the shutter diaphragm 32, and / or the beam deflection unit 24.

[0067] It is also conceivable that the control system 33 is adapted such that, during time windows in which no measurement of the specimen is to take place, the laser beam LS is interrupted by the laser interruption device, in particular the shutter 32. Thus, measurement pauses can be used to reduce the energy input into the specimen and thus protect the specimen from damage caused by excessive energy input.

[0068] The use of the laser microscope is particularly simple and is preferably carried out in the manner described below.

[0069] To insert a specimen into the laser microscope, the movement apparatus 13 first assumes the loading position, as shown in Fig. 1. In the loading position, the movement apparatus 13 is arranged such that its translucent receiving area 13a can be reached via the access opening 14 in the sample housing 10. In particular, the receiving area 13a is positioned directly flush below the access opening 14. The access opening 14 is preferably aligned congruently with the opening 41 in the outer housing 40, so that a user can insert a specimen, preferably with a sample holder, into the sample holder 12, in particular the receiving area 13a, via the opening 41 and the access opening 14.

[0070] In the next step, the lid 30 is closed. This can be done manually by the user, which reduces the risk of interfering with the travel path of the lid 30. Alternatively, the lid 30 can also be closed by a motor, which in a preferred variant can be triggered by a manual switch on the outside of the laser microscope.

[0071] As soon as the lid 30 is closed, the closed state of the lid 30 is detected by the locking switch 31 and preferably the locking mechanism 34 is triggered to lock the lid 30 in the closed state. The locking switch 31 signals the controller 33 that the lid 30 is closed.

[0072] The controller 33 can then release the shutter 32 and simultaneously activate the laser light source 21. However, it is also possible for the controller to activate the laser light source 21 and open the shutter 32 only when the musculoskeletal system 13 has reached its analysis position. For this purpose, the musculoskeletal system 13 can also be coupled to the controller 33 via a cable 28 in order to transmit corresponding position data to the controller 33.

[0073] It is also provided that the controller 33 initiates a movement of the movement apparatus 13 as soon as the lid 30 is closed. The movement apparatus 13 is then moved linearly, in particular horizontally, leaving the loading position and being transferred to the analysis position shown in Fig. 2.

[0074] In the analysis position shown in Fig. 2, the musculoskeletal system 13 is positioned such that the translucent cover area 13a is arranged above the laser lens 26. The laser beam LS, activated by the controller 33, thus reaches the specimen via the laser-transparent receiving area 13a. Light reflected via fluorescence is captured by the laser lens 26 and transmitted to corresponding detectors via the optical filter 25, which acts as a beam splitter, so that the scanned specimen can then be analyzed.

[0075] List of reference symbols

[0076] 10 sample housings

[0077] 11 Lens aperture

[0078] 12 Sample collection

[0079] 13 Musculoskeletal system

[0080] 13a Recording area

[0081] 13b Coverage area

[0082] 13c side wall

[0083] 14 Access opening

[0084] 15 Partition wall

[0085] 16 Exterior wall

[0086] 20 laser housings

[0087] 21 Laser light source

[0088] 22 deflecting mirrors

[0089] 23a first lens arrangement

[0090] 23b second lens arrangement

[0091] 24 beam deflection unit

[0092] 25 optical filters

[0093] 26 laser lens

[0094] 27 Laser optics

[0095] 28 cables

[0096] 29 Laser connection

[0097] 30 lids

[0098] 31 locking switch

[0099] 32 shutter aperture

[0100] 33 Control

[0101] 34 Locking

[0102] 40 outer casings

[0103] 41 Opening 100 Optical unit

[0104] LS laser beam

Claims

Patent claims 1. A safety device for a laser microscope, wherein the safety device comprises an optical unit (100) having a laser objective (26), a laser light source (21), a laser optics (27), a sample holder (12) for receiving a specimen and / or a sample holder, and an access opening (14) for loading the sample holder (12) with the specimen and / or the sample holder, wherein the access opening (14) is arranged offset from the laser objective (26) such that a laser beam (LS) emitted by the laser objective (26) is reflected and / or scattered and / or absorbed within the optical unit (100), wherein the sample holder (12) comprises a movement apparatus (13) which is movable from a loading position, in which the sample holder (12) is accessible via the access opening (14), to an analysis position, in which the sample holder (12) is arranged such thatthat a laser beam (LS) emitted by the laser objective (26) strikes the specimen and / or the sample holder, and wherein the access opening (14) is provided in an outer wall (16) of the optical unit (100), wherein the outer wall (16) is arranged opposite the laser objective (26), wherein the offset arrangement of the access opening (14) and the laser objective (26) causes a laser beam (LS) emitted by the laser objective (26) to be directed onto the outer wall (16) and cannot leave the optical unit (100) directly through the access opening (14).

2. Safety device according to claim 1, characterized in that the optical unit (100) is divided by a partition wall (15) into a sample housing (10) and a light-tight laser housing (20), in which a through opening (11) for the laser objective (26) and / or the laser beam (LS) is provided.

3. Safety device according to claim 1 or 2, characterized in that the access opening (14) can be closed by a cover (30).

4. Safety device according to claim 3, characterized in that the cover (30) is formed by a closure section of the movement apparatus (13).

5. Safety device according to one of the preceding claims, characterized in that the movement apparatus (13) comprises a light-permeable receiving area (13a) and an opaque covering area (13b) for covering the laser lens (26) in the loading position.

6. Safety device according to one of the preceding claims, characterized in that the movement apparatus (13) is motorized.

7. Safety device according to one of the preceding claims, characterized in that the laser optics (27) has at least one deflection mirror (22), at least one optical lens arrangement (23a, 23b), at least one beam deflection unit (24) and / or at least one optical filter (25).

8. Safety device according to one of the preceding claims, characterized in that a laser interruption device, in particular a shutter (32), for interrupting the laser beam (LS) is arranged between the laser light source (21) and the laser lens (26).

9. Safety device according to claim 8, characterized in that the laser interruption device is coupled to a control which is adapted to interrupt an emission of the laser beam (LS) by means of the laser interruption device when the locomotor system (13) is outside the analysis position and / or the optical unit (100), in particular the cover (30) and / or an outer housing (40) of the optical unit (100), is open.

10. Safety device according to claim 8 or 9, characterized in that the laser interruption device comprises a shutter (32) arranged in the beam path and / or a beam deflection unit (24) and / or a switch for switching off the laser light source (21) and / or the musculoskeletal system (13).

11. Safety device according to one of the preceding claims, characterized in that the sample holder (12) is positioned in the analysis position between the laser objective (26) and the preparation and / or sample holder.

12. Safety device according to one of claims 5 to 11, characterized in that the light-permeable receiving area (13a) is positioned in the analysis position between the laser objective (26) and the preparation and / or sample holder 13. Safety device according to one of the preceding claims, characterized in that the laser light source (21) comprises a fiber laser, in particular an ytterbium-doped fiber laser.

14. Laser microscope, in particular for the histological examination of tissue preparations, with a safety device according to one of the preceding claims.

15. Laser microscope according to claim 14, characterized in that the laser microscope is designed as an inverted laser microscope and / or as a multiphoton microscope.

Images