Ophthalmic laser system with real-time monitoring

Abstract

The present disclosure relates to an ophthalmic laser system (1) and a corresponding computer program product for generating sections in at least partially transparent tissue, comprising a therapy laser module (2); a beam guidance device (6) configured to direct a therapy laser beam (5) to a laser output (7) and to focus it in a treatment area outside the laser output (7) in order to generate at least one section in the tissue, wherein the beam guidance device (6) includes an xy-scan optic (9) configured to control a lateral deflection of the therapy laser beam (5); a tomographic measuring system (3) with a detector (14) configured to generate at least one depth profile (28) of the tissue, wherein the xy-scan optic (9) is further configured to deflect a measuring beam path between the laser output (7) and the detector (14) laterally;and a control device (18) which is configured to control the tomographic measuring system (3) in such a way that it records at least one depth profile (28), while the therapy laser module (3) and the beam guidance device (6) are controlled to generate at least one cut in the tissue.

Description

[0001] The present disclosure relates to an ophthalmic laser system for generating incisions in at least partially transparent tissue, comprising a therapeutic laser module; a beam guidance device configured to direct the therapeutic laser beam to a laser output and to focus it in a treatment area outside the laser output in order to generate at least one incision in the tissue. The beam guidance device includes an xy-scan optic configured to control a lateral deflection of the therapeutic laser beam. The ophthalmic laser system further comprises a tomographic measurement system with a detector configured to generate depth profiles of the tissue and a control device configured to control the beam guidance device, in particular the xy-scan optic, and the tomographic measurement system. The present disclosure also relates to a corresponding method and computer program product. State of the art

[0002] In ophthalmology, it is known to correct refractive errors of the eye, such as myopia, hyperopia and / or astigmatism, through refractive surgery, whereby the refractive power or refraction of the eye is changed.

[0003] Refractive surgical procedures are used to correct refractive errors. These procedures involve creating incisions in the corneal stroma, such as laser-assisted intrastromal keratomileusis (LASIK). In LASIK, a flap is created by cutting a flap from the cornea, typically using a femtosecond laser system. Such laser-based corneal cutting devices are also known as laser keratomes or laser microkeratomes. The laser creates photodisruption at its focus point, resulting in the formation of spots of isolated tissue within the stromal tissue. Tiny blisters may or may not develop at these spots. By positioning the focus points or spots together using a scanner system, these incisions are created within the corneal tissue.During LASIK, the flap is lifted, and then stromal tissue is removed using an excimer laser. After the treatment, the flap is folded back into place.

[0004] Surgical refractive correction has evolved into procedures that isolate and extract material from the cornea. The material to be isolated and extracted is commonly referred to as a lenticule, as it typically, but not necessarily, has the shape of a lens. The lenticule is then extracted through a small extraction incision in the cornea (e.g., SMILE: "Small Incision Lenticule Extraction"). Such a procedure is also referred to below as lenticule extraction. A laser keratome or laser microkeratome can be used for the necessary incisions, such as isolating the lenticule through incisions in the tissue or making an extraction incision to remove the lenticule. An example of an ophthalmic laser system capable of performing both flap incisions and lenticule delineation incisions is the Zeiss VISUMAX 600 / 800.This device features a laser keratome for cutting the corneal stroma on a first arm, through which a laser beam is guided and focused. For control and observation by the treating physician, a second arm is equipped with an operating microscope, which, however, only allows for en-face views of the eye.

[0005] In the aforementioned procedures, the shape of the cornea is specifically measured to plan the surgical correction of refractive errors, for example, contactlessly using a Scheimpflug camera or an optical coherence tomography system (also known as OCT, short for "optical coherence tomograph"). Contact measurement using ultrasound is also known. These measurements are generally performed on separate diagnostic devices outside of an operating room. Problems that arise during the procedure must be resolved by the treating physician based on a top-down or "en face" view of the eye, possibly with the aid of an operating microscope.

[0006] From US 11,547,605 B2, an ophthalmic device for processing eye tissue is known, comprising a laser source configured to generate a pulsed laser beam, focusing optics configured to focus the pulsed laser beam into the eye tissue, a scanner system for deflecting the pulsed laser beam to processing target points in the eye tissue, and an essentially separately controllable interferometric measuring system for optically detecting structures in the eye tissue. A circuit controls the measuring system such that it detects a cut first outer surface of a lenticule to be cut. The circuit controls the scanner system such that it directs the pulsed laser beam to processing target points on a second outer surface of the lenticule to be cut, positioned relative to the detected first outer surface, in order to cut the second outer surface of the lenticule.The circuit controls the measuring system in such a way that it detects the generated cutting paths and determines the remaining tissue bridges based on these paths. Based on the determined tissue bridges, the circuit identifies the untreated / still to be treated processing paths.

[0007] US 2006 106 371 A1 discloses a device, e.g., an OCT (optical coherence tomograph) or a confocal microscope, for measuring an optical breakthrough in tissue below a tissue surface caused by treatment laser radiation focused by a laser surgical device in a treatment focus located in the tissue. The device comprises a detection beam path with optics, in which the optics couple radiation emanating from the tissue below the tissue surface into the detection beam path. A detector device is arranged downstream of the detection beam path, generating a detection signal that indicates the spatial extent and / or location of the optical breakthrough in the tissue. The detection signal generated by the detector device can be used directly to control the treatment laser radiation.The illumination beam and the treatment laser beam can be combined via an optical coupling unit. However, prior to this combination, an adjustable deflection device, such as a scanner, is provided to achieve an independent lateral shift of the illumination beam relative to the treatment laser beam.

[0008] The devices described above each require separate control of a treatment beam and a measurement position. This makes real-time monitoring of the incisions in the ocular tissue complex. On the one hand, essentially separate datasets are generated for the current xy-scan positions (i.e., the positions of the treatment beam) and the simultaneously acquired measurement data (i.e., depth profiles, e.g., acquired via an OCT or confocal dataset), making it difficult to correlate the xy-scan positions with the measurement data. Furthermore, separate control data must be generated to control the respective units, and separate control mechanisms, e.g., separate scanning optics, must be provided. Thus, the known devices are complex in terms of both their control and data processing. Moreover, separate scanners for the imaging beam and the therapeutic laser beam are expensive to manufacture, assemble, and maintain.In the case of using micro-objectives, such use of separate scanners is not possible, or complicated and therefore expensive coupling mechanisms of the imaging beam into the therapy beam path would have to be provided in order to reduce problems caused by a changed wavelength, polarization-sensitive coupling, etc.

[0009] Furthermore, systems are known in which a tomographic imaging system (e.g., confocal or interferometric) for measuring an eye is controlled separately from the treatment laser. However, the scan patterns used to control the treatment laser are solely tailored to the therapy, not to the tomographic imaging procedure. This means that during treatment, in which the treatment laser is moved across the eye in an arbitrary scan pattern, no line scans, confocal sections, or grid lines for acquiring B-scans or C-scans are performed. Typical patterns for laser cutting in ocular tissue can be spiral, meandering, combined patterns of fast and slow scan components, and similar designs, which may optionally include transition zones with repetitions of the same path and / or different path speeds.In contrast, typical scan patterns desired for imaging systems are performed at a constant speed and, for example, for B-scans, in a straight line along various meridians (rotationally symmetrical around a center) or parallel to the center, or for C-scans as uninterrupted spirals or raster scans. Therefore, a scan pattern specifically tailored to the imaging (e.g., a line scan) cannot be used during treatment with the therapeutic laser. The treatment scan pattern must be modified. Consequently, a cross-sectional image cannot be readily acquired and displayed during treatment with such systems. Generally, only a cross-sectional image can be acquired before and / or after the laser procedure. Summary of Revelation

[0010] The purpose of this disclosure is to reduce or eliminate disadvantages of the prior art. In particular, it aims to provide an ophthalmological laser system, a computer program product, and, if applicable, a method, each of which enables real-time tracking of cuts in at least partially transparent tissue.

[0011] The problem underlying this disclosure is solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0012] More precisely, the task is solved by an ophthalmological laser system for creating incisions in at least partially transparent tissue, in particular corneal tissue of a patient's eye and / or a sample material (e.g., foreign or artificial tissue), with a therapeutic laser module comprising a therapeutic laser source configured to generate a therapeutic laser beam, and a beam guidance device configured to direct the therapeutic laser beam to a laser output and focus it in a treatment area outside the laser output to create at least one incision in the at least partially transparent tissue. The beam guidance device includes an xy-scan optic configured to control the lateral deflection of the therapeutic laser beam.Furthermore, the ophthalmic laser system has a tomographic measurement system with a detector configured to detect light incident through the laser output and reflected by tissue structures from a measurement beam path in order to generate tissue depth profiles. In addition, the ophthalmic laser system has a control unit configured to control the beam guidance device, in particular the xy-scan optics, and the tomographic measurement system. The xy-scan optics are configured to deflect the measurement beam path laterally between the laser output and the detector. The control unit is configured to control the tomographic measurement system such that it acquires at least one depth profile, while simultaneously controlling the therapy laser module and the beam guidance device to execute a therapy step in which at least one section is created in the at least partially transparent tissue.

[0013] In other words, an ophthalmic system is provided, comprising an imaging system for acquiring at least one depth profile, i.e., the tomographic imaging system, and an ophthalmic therapy laser module (abbreviated: therapy laser; also referred to as treatment laser), which is designed for making incisions in at least partially transparent tissue. The same xy-scan optics are provided for controlling the treatment laser beam path, i.e., the therapy laser beam, and the measurement beam path, i.e., a measurement beam, with respect to their lateral effective and measurement positions, respectively, within a treatment area. The ophthalmic system has a control unit for controlling the imaging system and the laser. This control unit is configured to operate during a procedure on the tissue, i.e.,While the therapy laser module is controlled to cut the tissue, tomographic measurement data is acquired by the imaging system. This means that a scan-based imaging system is functionally integrated with the ophthalmic therapy laser. The same xy-scan optics used to control the lateral position of the treatment laser's focus is also used to determine or select the lateral measurement position within the treatment area at which the respective depth profile is acquired.

[0014] While the therapy laser module is controlled to create the at least one cut in the at least partially transparent tissue, within the scope of the present disclosure, in particular, a time period in which the therapy laser is controlled in such a way that its focus in the treatment area traces a cutting path (also referred to as a therapy scan pattern) of the at least one cut and generates spots of separated tissue along the cutting path, which together form the at least one cut.

[0015] More precisely, the time period begins when the therapy laser module is controlled to generate an initial spot of separated tissue for a final cut and ends when the therapy laser module is controlled to generate a final spot of separated tissue for at least one cut. Specifically, a cutting process is performed during this time period, preferably automatically, without the therapy laser module being stopped in between to allow manual selection of further steps, undocking, or the like. The time period may also include phases in which the therapy laser is deactivated or switched off to allow for repositioning of the xy-scan optics and / or the z-scan optics, frequency switching, or similar actions, which may be necessary during the cutting process.

[0016] The at least one cut can comprise multiple cuts, which are performed consecutively in a coherently planned cutting path or cutting process. For example, the at least one cut can include lenticule delineation cuts and, if applicable, an opening cut, which are performed sequentially by the therapy laser module in a single (especially automated) cutting process. Thus, the last spot of separated tissue is also the last spot in the last cut performed in the present cutting process.

[0017] The at least partially transparent tissue can be corneal tissue from a patient and / or a sample material. The sample material could, for example, be a tissue sample from which an implant is cut, such as a donor cornea or similar. Alternatively or additionally, the sample material could also be test tissue for testing the ophthalmic laser system. Alternatively or additionally, the sample material could also consist of artificial tissue.

[0018] A depth profile, as defined in this disclosure, is information about structures in tissue along a depth direction, particularly at a specific point within the tissue. Preferably, the depth profile is the result of a point-based depth scan of the tissue, acquired by the tomographic measurement system, such as an A-scan or confocal scan. That is, the imaging system is specifically designed to acquire point-based depth profiles (A-scans / confocal scans / etc.) of the tissue. The depth direction is the direction in which the therapeutic laser beam exits the laser output. This preferably corresponds to a direction parallel to the optical axis of an eye or parallel to an axis passing through the center of the pupil of the patient's eye if the tissue is an eye or part of an eye and the eye is in a therapeutic position. The depth direction is also referred to as the z-direction.Directions perpendicular to the depth direction are referred to as the x-direction and y-direction, or as lateral directions.

[0019] Lateral deflection within the meaning of this disclosure means that the beam or beam path in question (i.e., the therapeutic laser beam and / or the measurement beam path) is angled and / or shifted such that its effective or measurement position within the treatment area is laterally displaced. The effective position of the therapeutic laser beam is defined by its focal point within the treatment area and essentially corresponds to the position at which the therapeutic laser beam can generate a spot. The measurement position of the measurement beam path corresponds to the position at which the tomographic measurement system generates the depth profile.

[0020] The laser output is, in particular, an opening or a transparent section through which beams, e.g., the therapeutic laser beam during laser treatment, can exit the ophthalmic laser system and enter the treatment area. A holder is arranged at the laser output, which is specifically designed to hold an interchangeable treatment interface that is designed to dock onto the tissue to be cut or the patient's eye to be treated. The treatment area is a space outside the laser output in which tissue or the patient's eye is positioned during laser treatment.

[0021] This device provides real-time tracking and control of tissue incisions during their creation. Advantageously, this results in a particularly accurate image of the incision, as effects such as lost reference points can be avoided. Furthermore, the provision of at least one depth profile, which allows for subsequent user review, is integrated into the ongoing therapy procedure in such a way that the treating physician does not need to initiate any additional action to record depth profiles for monitoring and documentation purposes, thus saving time. The device is also particularly simple in design due to the use of the same xy-scan optics to control both the measuring beam and the therapy laser beam.Accordingly, costs for the manufacture, assembly and maintenance of separate xy-scan optics or additional control mechanisms are saved.

[0022] Furthermore, the disclosed device enables live monitoring of depth profiles, in particular cross-sectional views of the tissue, during the creation of a section with the therapeutic laser. This allows a treating physician to make adjustments during treatment based on the real-time control data. Thus, problems arising during treatment can be addressed particularly quickly, and treatment outcomes can be improved. In particular, the subject matter of the present disclosure enables the tracking of a spot carpet in a tomographic representation, allowing gaps or irregularities in the spot carpet to be detected at an early stage.This, in turn, makes it possible to discontinue treatment or perform a laser correction step before any mechanically invasive procedure is carried out on the tissue, even if sufficient tissue separation is not present. Complications arising from the extraction or integration of structures such as lenticels or similar lesions can thus be avoided.

[0023] According to the present disclosure, tomographic views can therefore be generated without the need to execute a specifically designed scan pattern before or after tissue cutting. Furthermore, a live display of tomographic images in the form of depth profiles or a depth image composed of several depth profiles can be provided during treatment (especially ophthalmic surgery) with the therapy laser module, while the system is simultaneously designed to be particularly simple and cost-effective, since the same xy-scan optics are used for both the treatment laser and the imaging beam. Despite the use of the same xy-scan optics by the treatment laser and the imaging beam, the acquisition of a cross-sectional view of the tissue is not limited to the time before or after a completed procedure, but can be performed during the procedure.during which at least one cut is made in the tissue.

[0024] Preferably, the control unit can be configured to assign each recorded depth profile and xy-parameter, which allows for a unique assignment to the corresponding xy-scan position at which the depth profile was recorded, as a data pair. This enables particularly simple and efficient processing of the recorded data (depth profiles and xy-parameters). In other words, the control unit is configured to assign position data of the xy-scan optics, i.e., corresponding to the xy-scan position for measurement and / or treatment in the treatment area / on the eye / on the tissue, or another parameter that represents the position data, is proportional to it, or otherwise makes it uniquely identifiable, to the respective depth profile of the imaging system. An example of such an other value is, for example...A control voltage for the xy-scan optics, or a value shifted spatially or temporally by a specific amount or factor, or the like. The control unit thus provides at least one data pair containing the depth profile and the xy-scan position at which the corresponding depth profile was acquired, or the corresponding xy-parameters.

[0025] Alternatively or additionally, it is conceivable to investigate spot dynamics, optionally without considering the xy-scan position. Investigating spot dynamics more precisely means observing the formation of the spots (e.g., velocity, precise position, size, extent, etc.).

[0026] The control device can be designed, in particular, to acquire a multitude of depth profiles and provide a multitude of corresponding data pairs (i.e., each depth profile and its associated yx scan position) in order to provide a depth image of the tissue based on the data pairs, in particular in the form of a B- or C-scan or a number of A-scans. In particular, the control device can generate the depth image based on several adjacent depth profiles, in particular based on several depth profiles (A-scans) lying along a line, especially a straight line. A B-scan is a recording of a section plane extending in the depth direction of the tissue, i.e., essentially a cross-sectional view. A B-scan of tissue can, in particular, extend along a radial plane, e.g.,A B-scan is a three-dimensional image of tissue, measured along an optical axis or an axis extending through the center of the patient's pupil. Specifically, a B-scan is generated by combining multiple A-scans. C-scans are three-dimensional images of tissue and can be generated by combining multiple A-scans or multiple B-scans.

[0027] Preferably, the ophthalmic laser system has a user interface designed for inputting data and / or commands. For example, the user interface may include a mouse, keyboard, joystick, buttons, a touchscreen, voice control, gesture control, and / or the like. More preferably, the ophthalmic laser system has a display device. The display device preferably includes a display and / or an eyepiece. The display can be, for example, a monitor, a head-up display, or the like. Furthermore, the display device can be the touchscreen and thus part of the user interface. This allows the user to receive information from the ophthalmic laser system via the display device and, if necessary, to input data into the ophthalmic laser system.

[0028] The user interface can include an input element that allows the user to select a depth image to be displayed on the screen. Specifically, the user interface can provide the user with a selection option to choose what type of depth image is captured and / or displayed. That is, the user can decide whether to view an A, B, and / or C scan and / or which area to view, e.g., which section plane is particularly relevant. Preferably, the control unit is configured to control the screen, for example, depending on the user's selection, to output the depth image as A, B, or C scans. This gives the user a high degree of flexibility in selecting views and makes it particularly easy to identify errors in the section view.

[0029] Furthermore, the control unit can provide additional functions via the display device and / or the user interface. For example, the control unit can be configured to prompt the user to stop or continue a treatment. The control unit can preferably be designed to ask the user whether there are any errors in the cut pattern, such as irregularity and / or a lack of continuity in the spot pattern forming the cut, and whether they wish to take further action. Alternatively, the control unit can be designed to automatically identify errors in the cut pattern, notify the user, and, if necessary, provide the user with decision-making and planning support for further actions.The control unit can preferably be configured to output the measurement data of the tomographic measuring system to a planning unit of the control unit for the replanning of a further laser treatment, such as a corrective treatment. The control unit is further preferably configured to carry out the replanning.

[0030] The at least one incision that can be made using the ophthalmic laser system described above is preferably a lenticule delineation incision. Lenticule delineation incisions are incisions that define a lenticule. More precisely, lenticule delineation incisions include a capcut, which defines an anterior surface of the lenticule; a lenticule cut, which defines a posterior surface of the lenticule; and, optionally, a substantially ring-shaped sidecut, which connects the lenticule cut and the capcut and defines a circumferential border of the lenticule. Furthermore, the at least one incision may include an opening incision, also referred to as an "incision." The opening incision is an incision created during lenticule extraction treatment to connect the lenticule delineation incisions with the anterior tissue surface and thus open them, allowing the lenticule to be removed from the tissue through the opening incision.If the tissue incision is flawed, lenticule extraction can be particularly difficult or even impossible, and the attempt may result in significant tissue damage. Therefore, it is especially advantageous to use the ophthalmic laser system described in the report to control lenticule delineation incisions. However, it is also conceivable that at least one incision is, for example, a flap incision that defines a flap.

[0031] Preferably, the control device is designed to control the tomographic measurement system such that it records depth profiles essentially continuously or at regular intervals along a section path while at least one section is being created in the tissue. "Essentially continuously" in this case means that depth profiles are recorded during the scanning of the section path or section image by the xy-scan optics for sectioning the tissue, immediately one after the other or without significant pauses in between. In other words, no additional trigger event is required to initiate the recording of a depth profile. The basis for triggering the recording is preferably only limitations imposed by the physical requirements of the tomographic measurement system and the planned section image.If the depth profiles are essentially acquired along the cutting path or trajectory, this can be done at regular time or spatial intervals while the xy-scan optics traverse the therapy scan pattern. The regular intervals can, for example, correspond to the spacing at which the spots are placed, so that a depth profile can be acquired for each spot, i.e., immediately before, after, and / or during spot generation by the therapy laser. Preferably, the speed of the xy-scan optics and the frequency at which the therapy laser is activated to generate a spot are coordinated such that the distance between two spots along a path is always the same.

[0032] This design of the present disclosure object allows for the acquisition of a particularly large number of depth profiles, thus providing a particularly wide selection of depth profiles, e.g., from all possible radial or lateral section planes (B-scans). Accordingly, even small errors in the cross-sectional image can be easily detected. Furthermore, controlling the xy-scan optics is particularly simple.

[0033] Furthermore, it is preferred if the control unit is configured to select specific depth profiles or data pairs from the continuously acquired depth profiles or corresponding data pairs, which were acquired or generated at predetermined or selected xy-scan positions, in particular a predetermined or selected line or grid. This can also be referred to as "remapping." This relieves the storage or computing unit in which the data pairs are stored and / or processed. At the same time, a high resolution within the depth images can still be ensured. The remaining depth profiles or data pairs can, for example, be deleted or simply stored unprocessed.

[0034] Preferably, the control device is designed to control the tomographic measurement system such that it acquires depth profiles at predetermined xy-scan positions or at predetermined times, in particular only during a crossing of the predetermined or selected xy-scan position. In other words, the control device is designed to trigger the generation of individual depth profiles when the xy-scan optics, during a sectioning maneuver (determined by a therapy scan pattern) for cutting the tissue, reach or cross a predetermined acquisition pattern (i.e., an imaging scan pattern). That is, the triggering of the generation of the individual depth profiles is aligned with a scan pattern necessary for tomographic imaging. Thus, an additional trigger event is provided.This allows the number of data pairs to be stored and processed to be kept relatively low from the outset, thus reducing the computational and storage effort required by the control unit.

[0035] Preferably, the predetermined xy-scan positions for acquiring the depth profiles lie on a predetermined line, such as a radial line, or on a predetermined dot or line grid. The predetermined lines or dot or line grid can preferably intersect a predetermined xy-slicing path (i.e., run transversely or obliquely to it) along which the therapy laser travels to perform the at least one cut in the tissue. This is particularly advantageous for providing a straight depth scan, even if the predetermined xy-slicing path is uneven with respect to its xy-axis trajectory and the xy-scanner, for example, traces a spiral, concentric circular segments, a star-shaped pattern, or the like. The predetermined xy-slicing path can, for example, be spiral and traversed from the inside out or vice versa.Alternatively, the predetermined xy-cutting path can be grid-like and comprise a number of parallel lines whose xy-coordinates are each parallel to one another. Furthermore, the cutting path can extend along a grid of fields, each containing defined sub-cutting paths, which are processed sequentially with the therapeutic laser (especially with micro-objectives). The predetermining line can extend with respect to the cutting path, particularly to the parallel lines, such that it coincides with it, runs parallel to it, or intersects it, especially perpendicular to it.

[0036] Furthermore, it can be advantageous if the control unit is designed to trigger the acquisition of the respective depth profile by the tomographic measurement system before reaching or crossing the predetermined xy-scan position. In particular, a time interval between triggering the acquisition of the depth profile and reaching the predetermined xy-scan position can be selected such that any delay or dead time between triggering the acquisition and the actual execution of the depth profile acquisition is compensated for. For example, a specific acquisition duration may be required for acquiring the depth profile, especially an A-scan, and the dead time between triggering the acquisition and crossing the predetermined xy-scan position or line can be dimensioned to be, for example, half the acquisition duration.such that the predetermined xy-scan position or line is crossed when half the recording time has elapsed.

[0037] The time interval can be constant. Alternatively, the time interval can be variable, depending on an imaging scan pattern and a therapy scan pattern (described in more detail later), or adjusted during operation depending on environmental and system parameters, such as rising temperature, readiness or the cycle time of the measuring light source, or similar factors. In other words, the control unit can be designed to adjust the triggering or initiation of the acquisition of the corresponding depth profiles in such a way as to compensate for characteristics of the xy-scan optics or other components or controls of the ophthalmic laser system, such as differing or potentially non-linear speeds of the individual scanners, delays, the acquisition time of the tomographic measurement system, etc.For example, a first trigger can be provided when a depth profile recording is to be initiated, and a second trigger can be provided after a predetermined time to actually perform the depth profile recording. The second trigger can be provided, for example, when the measuring light source is ready for recording. The predetermined time is variable, allowing for particularly high image quality.

[0038] The control device can further preferably be designed to control the xy-scan optics to perform compensatory deflections while the depth profile is being acquired, in order to counteract spatial smearing during the acquisition. In other words, to compensate for spatial smearing caused by the xy-scan optics, a compensatory deflection of the measuring beam path is generated. For example, a compensatory deflection can mean that the xy-scan optics are controlled to be briefly delayed or to perform a counter-movement when crossing the predetermined xy-scan position. Delay means that the speed of the xy-scan optics' adjustment for acquiring the depth profile is reduced, particularly without stopping completely. Counter-movement means that the direction in which the xy-scan optics are adjusted, particularly to follow the planned section path, is reversed for acquiring the depth profile.The counter-movement can be small in relation to the previous adjustment of the xy-scan optics or the preceding section of the scanning path. Particularly preferably, the control device can be configured to initiate the acquisition of the depth profile when the xy-scan optics stop, or to stop the xy-scan optics in order to acquire the depth profile.

[0039] Spatial blurring is a blurring effect that can occur during a point-based depth scan (e.g., an A-scan or confocal scan) and is caused by the movement of the xy-scan optics during the acquisition of the depth profile. According to the present disclosure, this blurring can advantageously be reduced. This means that a focal point or point of the best image quality in the depth scan or depth profile lies particularly precisely at the predetermined xy-scan position. Both the quality and the spatial accuracy of the depth image can thus be improved. The user or a treating physician therefore has a better basis for diagnosis, and treatment can be improved. In other words, it can be ensured that the acquired depth profiles correspond as closely as possible to the associated xy-scan positions.For example, the provision of a particularly sharp B-scan can be ensured precisely along a specific radial beam. This allows for particularly accurate diagnoses.

[0040] Furthermore, it is advantageous if the therapy laser module can be reconfigured during treatment. This reconfiguration can occur during a single incision and / or between two incisions.

[0041] For example, a reconfiguration can include a switching phase between the generation of two spots by the therapy laser module, during which the xy-scan optics and / or a z-scan optics switch from the position of one spot to the position of another. In particular, one spot is part of a first slice and the second spot is part of a second slice. In other words, the switching phase preferably occurs when switching from a first slice to a second slice, as this switching phase is long enough to provide sufficient time for acquiring the depth profile. Specifically, the switching phase involves adjusting the z-scan optics, preferably with a larger adjustment range than that between two adjacent spots of a single slice.The switching phase is particularly preferably located between lenticular limiting and / or opening cuts, especially preferably between the lenticular cut and the side cut or between the side cut and the cap cut or between the cap cut and the opening cut, since the adjustment range is particularly long here.

[0042] Alternatively or additionally, a reconfiguration can involve adjusting the settings of the therapy laser module and / or the beam guidance device. This can occur during a single slice or between slices. For example, the reconfiguration might involve changing the frequency of the therapy laser source and / or the switching frequency of the xy-scan optics and / or the z-scan optics. Furthermore, the reconfiguration might include an intermediate routine to finalize the settings adjustment.

[0043] Furthermore, it is advantageous if the control device is designed to control the xy-scan optics and the tomographic measurement system in order to acquire at least one depth profile during the switching phase. In particular, the control device can be designed to control the xy-scan optics such that the xy-scan optics move to a predetermined acquisition point or a predetermined xy-scan position, and especially to follow a predetermined acquisition profile (i.e., an imaging scan pattern or a part of an imaging scan pattern). Furthermore, the control device preferably controls the tomographic measurement system to acquire at least one depth profile at the predetermined acquisition point or along the predetermined acquisition profile. In other words, the control device is designed to acquire at least one depth profile, and especially to execute predetermined imaging scan patterns (e.g.,Rapid line scans are performed by the tomographic measurement system during switching phases of the therapy scan pattern. Generating a depth profile preferably takes less time than switching, particularly the z-scan optics. Accordingly, it is possible to perform a rapid imaging scan during the switching phase without significantly increasing the time required to acquire at least one slice, especially when multiple slices are being generated.

[0044] The predetermined acquisition profile can be formed by a specific arrangement of acquisition points, e.g., by a matrix or at least a line radially oriented with respect to the optical axis or the pupil center, or by a meandering line or by parallel lines. It is particularly advantageous if the depth profiles underlying the depth acquisition are acquired in a single, continuous control step. This can lead to simplified image processing. This is especially easy with the control described above, in which the switching phase is used to acquire at least one depth profile. Furthermore, this control advantageously allows for the generation of a continuous snapshot between the creation of two spots. This makes it possible to observe the sectioning process with particular precision.It is particularly advantageous to use the switching times in a final section of the cut to capture depth profiles. For example, a switching phase between a first and a second cut can be used to provide depth profiles / recordings, enabling particularly time-efficient capture of depth profiles from a very large section. It is also conceivable to use a switching phase between the last row or the last circular / spiral ring of a cut to capture the depth profile.

[0045] Accordingly, such control is particularly advantageous when, for example, a z-scan optic is used, which is slower than the xy-scan optic. The z-scan optic, which is preferably part of the ophthalmic laser system, is a mechanism for shifting the focus of the therapeutic laser beam in the treatment area in the depth direction or z-direction. The depth direction or z-direction refers to a direction that runs parallel to the therapeutic laser beam at the laser output. The z-scan optic can, for example, include a zoom lens, such as a movable lens or lens group, or a movable tube lens.

[0046] The xy-scan optics are a mechanism for laterally controlling or shifting the focus of the therapeutic laser beam and / or the measurement beam path within the treatment area, perpendicular to the depth direction or in an x ​​and / or y direction. It can include an x-scanner and a y-scanner. Control in the x and / or y directions, or in a lateral direction, in this sense means that the position of the focus is shifted in a direction that is perpendicular or transverse to the therapeutic laser beam at the laser output. The xy-scan optics can, for example, incorporate a number of adjustable mirrors, particularly galvanometrically. When the relatively slow z-scan optics switch, phases occur in the therapy scan pattern with the therapeutic laser switched off (essentially short pauses in the cutting process), during which the z-scanner repositions itself and the xy-scan optics may have an idle time.Such a situation can arise when the z-scan optics are controlled to switch between two sections at different depths and / or when a section image or section path of at least one section has a z-dimension, i.e., the section path is curved in a depth scan. The time required to switch the z-scan optics can be used to acquire at least one depth profile, as this is possible regardless of the z-scan optics settings. Therefore, acquiring the depth profiles does not significantly increase treatment time, or only minimally.

[0047] According to a preferred embodiment, the control unit is designed, particularly during a planning phase in which the sections are planned and the therapy scan pattern is determined, to determine an imaging scan pattern (also referred to as an imaging target structure) of depth profiles, which is required for providing depth images. In other words, the control unit determines at which points depth profiles are to be acquired and provides these as a data set. The imaging scan pattern is, in particular, a pattern in which depth profiles are to be acquired in order to provide specific depth images. The imaging scan pattern can, for example, have a radial, parallel-striped, or grid-like pattern of B-scans, a C-scan, a grid of A- or B-scans, etc. That is, the control unit determines early on which depth images are to be acquired and where.The pattern used for depth images must be specified. The imaging scan pattern can be customized by the user, for example, by allowing them to select specific desired depth images via the user interface, or by using one or more pre-stored default patterns.

[0048] Preferably, the control unit is designed to identify at least one defective area of ​​the imaging scan pattern that is not part of a therapy scan pattern being scanned by the xy-scan optics during section generation. In other words, the imaging scan pattern may contain xy-areas that are not covered by the therapy scan pattern, or, to put it another way, that do not overlap an xy-area in which at least one section is planned. This allows such defective areas to be taken into account during the planning phase, enabling particularly efficient and / or requirement-specific planning for controlling the therapy module, the xy-scan optics, and the tomographic measurement system. The therapy scan pattern is a pattern that is scanned by the xy-scan optics to generate the at least one section. The therapy scan pattern can, for example,exhibiting a spiral and / or meandering pattern. The therapy scan pattern is specifically a pattern that is traced by the xy-scan optics in a continuous therapy step, during which the tissue is cut by the therapy laser module. "Continuous" here means, in particular, that the execution of at least one cut is not interrupted during normal operation (i.e., without an emergency stop or similar).

[0049] According to a preferred example, the control device is further configured to control the tomographic measurement system and the xy-scan optics such that, during the switching phase and / or before and / or after the generation of the at least one slice through the therapy laser module is complete, it acquires depth profiles in the at least one defect area. In other words, areas of the imaging scan pattern that are not included in a therapy scan pattern can be addressed before or after the therapy scan pattern has finished, or in at least one of the switching phases of the therapy scan pattern. The control device can therefore be configured to control the tomographic measurement system and the xy-scan optics such that depth profiles are acquired outside the therapy scan pattern or during the switching phases.This is particularly advantageous if at least one defective area is large and it is beneficial to record it in a continuous manner.

[0050] Preferably, the control unit is configured to modify the therapy scan pattern during the planning phase, before the at least one incision is made and after the at least one defect area has been identified, such that the at least one defect area is wholly or partially covered by a modified therapy scan pattern. In other words, the therapy scan pattern can be extended by the control unit in such a way that the at least one defect area is reduced or eliminated. In this case, the therapy scan pattern can contain sections in which the xy-scan optics cover an area where the therapy laser does not irradiate the tissue, particularly corneal tissue, or is inactive. This is a particularly simple solution when the defect area to be integrated is small.This allows for the most complete imaging scan pattern possible during the therapy step, without significantly extending the treatment time. Furthermore, it makes the process particularly easy to control, as few or even no additional scans are required to acquire depth profiles in at least one defective area.

[0051] The problem underlying the present disclosure is further solved by a method for monitoring an ophthalmic laser treatment by an ophthalmic laser system described above, comprising the following steps: - Controlling the tomographic measurement system of the ophthalmic laser system in such a way that it records depth profiles, while the therapy laser module of the ophthalmic laser system is controlled to create at least one cut in at least partially transparent tissue, whereby a position for recording the depth profile is set by the xy-scan optics of the ophthalmic laser system.

[0052] Monitoring is primarily live. This means that the ophthalmic laser treatment can be monitored while it is being performed. More precisely, at least a depth profile is recorded during the treatment, and this can be used directly to monitor the treatment ("real-time monitoring"), taking into account a period for data acquisition and processing by the control unit, especially while the treatment is still in progress.

[0053] Preferably, the procedure may include a step in which the ophthalmic laser treatment can be optionally stopped and / or the treatment plan adjusted. The procedure can therefore optionally also be claimed as a method for stopping and / or modifying the ophthalmic laser treatment.

[0054] The method may further include all steps described in the present disclosure within the context of controlling the ophthalmic laser system and its components, such as forming the at least one data pair, etc. The components of the ophthalmic laser system include, in particular, the control unit, the therapy laser module, the tomographic measuring system, and the beam guidance device, including the xy-scan optics and the z-scan optics.

[0055] The problem underlying the present disclosure is further solved by a computer program product for monitoring an ophthalmic laser treatment using an ophthalmic laser system described above. The computer program product has a program code which, when executed by the control unit of the ophthalmic laser system, performs the aforementioned method.

[0056] Preferred configurations of some of the components of the ophthalmic laser system are described in more detail below.

[0057] The therapy laser module is designed to provide therapy laser radiation via the therapy laser source and to deliver this radiation as a therapy laser beam at the laser output. In particular, the therapy laser module is suitable and configured for performing lenticule extraction procedures (e.g., SMILE). The therapy laser beam is, in particular, a pulsed laser beam, preferably an ultrashort pulsed laser beam, and more preferably a femtosecond laser beam. The therapy laser module is designed such that the therapy laser beam, at its focus, is suitable for creating sections in at least partially transparent tissue (hereinafter referred to as "tissue"), in particular corneal tissue of a patient's eye or sample material.The energy density of the laser beam at its focus is adjusted such that spots of locally or point-like separated tissue (referred to as "spots") can be generated within the tissue, optionally with the formation of tiny bubbles or vesicles, also known as cavitation bubbles or gas bubbles. A series of these spots forming a pattern ("spot pattern" / "bubble pattern") creates an incision in the tissue. Furthermore, the therapeutic laser module is designed such that the energy density of the therapeutic laser beam outside its focus is adjusted so that it is hardly absorbed by the tissue, particularly corneal tissue. Preferably, the laser power is adjustable.

[0058] Furthermore, it is preferred that the laser power and / or scan time of the therapeutic laser beam and / or the distance between scan points of the therapeutic laser beam can be adjusted. This makes it particularly easy to integrate different imaging scan patterns into the therapy step.

[0059] The tomographic measurement system is a system that enables tomographic imaging of at least partially transparent tissue, particularly the patient's eye. This means it identifies tissue structures that can be displayed as depth images on the screen. Specifically, the tomographic measurement system is designed to capture structures within the tissue along the z-direction, or depth direction. These structures are primarily those that reflect or scatter light, or more precisely, interfaces between areas with different refractive indices. The tomographic measurement system can also be referred to simply as a tomograph.

[0060] Preferably, the tomographic measuring system includes a measuring light source, in particular a measuring laser source, which generates measuring light for illuminating the tissue, reflected by the structures within the tissue. The reflected measuring light enters the ophthalmic laser system through the laser output, is focused, and guided by the beam guide along the measuring beam path to the detector. Preferably, the measuring light source is connected to the measuring beam path such that the measuring light generated by the measuring light source is focused and guided by the beam guide to the laser output. That is, preferably, both the light emitted by the measuring light source and the light incident on the laser output are guided at least partially along the same path. Thus, targeted and particularly good illumination of the tissue area to be measured can be achieved.

[0061] The measuring light source is, in particular, a light source provided separately from the therapy laser source, especially a therapy laser source itself. The measuring light preferably has a coherence wavelength that differs from the coherence wavelength of the therapy laser radiation. This ensures that light from the therapy laser beam, reflected by the tissue, does not significantly interfere with the measurement by the tomographic measuring system. Alternatively, the measuring light can also have the same coherence wavelength as the therapy laser. Another alternative is to divert a beam from the therapy laser source out of the therapy beam path and guide it, at least partially, along a different path than the therapy laser beam. This also ensures that no coherent superposition of the measuring light and the therapy light in the detector interferes with the measurement by the measuring device.

[0062] Preferably, the tomographic measuring system is an optical coherence tomography system (OCT for "optical coherence tomograph"). The OCT can have the measuring light source, in particular the measuring laser source, from which a measuring beam (in particular a measuring laser beam) and a reference beam (in particular a reference laser beam) are emitted. The reference beam and the measuring beam can be separated from each other, for example, by a beam splitter or fiber coupler, which is located downstream of the measuring laser source.

[0063] The measuring beam is guided to the tissue, in particular via a measuring arm, where it is reflected. The reflected light is then guided via the measuring arm to an interferometric detector. The interferometric detector has, for example, an interferometer arranged at the input side, which, among other things, superimposes the measuring beam and the reference laser beam to generate an interference beam, and one or more sensors, in particular photodiodes, for converting the light from the interference beam into electrical signals. Preferably, two sensors are provided for so-called "balance detection." The measuring arm thus essentially corresponds to the measuring beam path. The reference beam is guided to the detector, in particular via a reference arm, which is designed to measure interference between light from the measuring arm and the reference arm.

[0064] The xy-scan optics allow the measurement beam to be deflected laterally, enabling the imaging position for recording the depth profile to be moved across the tissue to obtain depth images at various locations. The xy-scan optics used to deflect the measurement beam are the same xy-scan optics used to deflect (i.e., laterally control) the therapy laser beam.

[0065] Preferably, according to the present disclosure, OCT images are acquired in the frequency domain ("frequency-domain OCT"). In frequency-domain OCT measurements, the detector detects interferences from individual spectral components of the measurement light source. The respective spectral component determines the measured depth. This enables simple and fast measurements, as a complete depth image can be acquired without the need for a movable reference mirror, the movement of which is time-consuming and can generate artifacts. Thus, high measurement stability and speed can be achieved. Furthermore, frequency-domain OCT offers particularly high sensitivity and requires a relatively low radiant power from the measurement light source, which increases the efficiency of the tomographic measurement system.Frequency-domain OCT typically distinguishes between the use of a tunable source (“swept-source OCT”) and the use of a dispersive detector (“spectral-domain OCT”).

[0066] According to the present disclosure, the tomographic measurement system is preferably a swept-source OCT. In swept-source OCT, the frequency of the measurement light source, often a measurement laser source, is sequentially tuned, i.e., the individual spectral components are provided by the measurement light source one after the other. That is, the measurement light source is preferably a tunable laser (swept source), for example, a broadband laser, a supercontinuum laser, and / or an ultrashort pulse laser. A VCSEL laser (vertical external-cavity surface-emitting laser) is particularly preferred. The tunable laser can be a narrowband light source at a given time, the center frequency of which can be selectively varied over time, or it can be composed of a plurality of narrowband light sources. Preferably, the sweep rate of the swept-source OCT is adjustable.This allows the OCT to be precisely adapted to the prevailing conditions, resulting in particularly high measurement accuracy and / or speed. A swept-source OCT can achieve exceptionally high sensitivity and a particularly low signal-to-noise ratio over a very wide depth range.

[0067] Alternatively, a spectral-domain OCT can be used, in which (similar to time-domain OCT) a broadband light source is used, but the frequency components of the interference signal are not separated at the measuring light source, but before detection, for example by an optical grating.

[0068] Alternatively, OCT data can be acquired in a time domain ("time-domain OCT"). In this method, a movable reference mirror can be positioned in the reference arm. By moving the reference mirror, a path difference between the measuring beam and the reference beam can be adjusted, thereby setting the measured depth.

[0069] Alternatively, the tomographic measurement system could be a confocal system or a confocal microscope. This is a particularly cost-effective way to obtain a high-resolution depth image of a patient's eye, especially for measurements of the anterior segment. Alternatively, the tomographic measurement system could also be a two-photon microscope or an SHG imaging system, etc.

[0070] The beam guidance device is, in particular, an arrangement of optical elements designed to guide at least the therapeutic laser beam from the therapeutic laser source to the laser output, to focus it into the treatment area, and to control the position of the focus within the treatment area. For example, in addition to the xy-scan optics, the beam guidance device has focusing optics at or immediately before the laser output, which are provided for focusing the therapeutic laser beam into a treatment area outside the laser output. The beam guidance device may also include one or more additional components such as a collimator, mirrors, beam splitter, and the like.

[0071] Preferably, the beam guidance device incorporates a coupling point at which the measurement beam path can be coupled into or out of the beam guidance device, particularly concentrically to a therapy beam path of the therapy laser beam. In this case, the xy-scan optics are located at the coupling point or between the coupling point and the laser output. This ensures that the depth profile, especially the OCT scan, and the therapy treatment can be controlled together with exceptional precision, particularly using the same xy-scan optics.

[0072] Preferably, the coupling point is designed as a deflecting mirror that deflects the therapy laser beam when the therapy laser module is operated. More preferably, the deflecting mirror is a pinhole mirror or a pinhole aperture through which the measuring beam is guided when the tomographic measuring system is operated. The pinhole mirror or pinhole aperture, i.e., its opening, is preferably positioned where the therapy laser beam strikes the deflecting mirror (i.e., the pinhole mirror or pinhole aperture is concentric with the therapy laser beam). A further preferred feature is that the diameter of the pinhole mirror or pinhole aperture is smaller than the diameter of the therapy laser beam at the point where it strikes the deflecting mirror. This is a particularly simple and elegant solution for coupling the measuring beam into the therapy laser beam without significantly impairing the quality of the therapy laser beam.Alternatively, the coupling point could incorporate a beam splitter cube that reflects the wavelength of the therapeutic laser beam and transmits the wavelength of the measurement beam. This can be particularly advantageous when the two wavelengths differ significantly. Another alternative is to achieve coupling by polarizing the therapeutic laser beam and the measurement beam differently, for example, by placing polarizers at or in front of the coupling point.

[0073] The ophthalmic laser system preferably has a base station which includes the therapy laser module, the beam guidance device, the laser output and the tomographic measuring system.

[0074] The base station preferably has a base housing from which a laser arm extends, on which the laser output is located. The laser arm can be pivotably, movable, or fixedly connected to the base housing. The therapy laser source is preferably located in the base station, more precisely in the base housing. The beam guidance device can extend through the laser arm and preferably through the base housing. The coupling point is also preferably located in the base housing. Furthermore, it is advantageous if the detector and, if applicable, the measuring laser source are located in the base station, more precisely in the base housing. The xy-scan optics and / or the z-scan optics can also be located in or on the base station, more precisely in the base housing and / or in the laser arm. Optionally, a pivotable microscope arm can also be attached to the base housing, which carries a surgical microscope.

[0075] Preferably, the base station further comprises the display device. More preferably, the base station comprises the entire control unit or at least certain functional sections thereof. The control unit is configured to control the ophthalmic laser system, in particular the therapy laser module, the tomographic measurement system, and the display device. The control unit of the ophthalmic laser system is configured to control the therapy laser module and the tomographic measurement system, as well as to control the methods disclosed, which are carried out using the ophthalmic laser system, in particular the therapy laser and the tomographic measurement system.

[0076] The control unit preferably has one or more of the functional sections described below, specifically a scan control section, a measurement control section, a therapy control section and a planning section, which are interconnected for data transmission or can optionally be connected.

[0077] Preferably, the control unit has a scan control section configured to control at least the xy-scan optics. That is, the preferred scan control section is configured to control the lateral deflection of a beam, such as the therapy laser beam and / or the measurement beam path, which is guided by the beam guidance device. Optionally, the scan control section can also be configured to control the z-scan optics and / or other components of the beam guidance device. Preferably, the scan control section can be configured to issue control commands to or communicate with the measurement control section, for example, to trigger the acquisition of a depth profile at the predetermined xy-scan position.

[0078] Preferably, the control unit further comprises a measurement control section configured to control the tomographic measurement system. This means the measurement control section is configured to control the measurement light source and / or read and process data from the detector (e.g., to store it and / or generate a depth image from the data and / or provide the data or depth image). For example, the measurement control section can include a CPU or GPU, RAM, and / or a storage unit. Preferably, the measurement control section is further configured to control the measurement laser source and / or communicate with the scan control section, in particular to issue control commands to the scan control section and / or receive xy-position data from the scan control section. The measurement control section can thus optionally control, via the scan control section, which part of the tissue is measured, e.g., to measure the defect areas.

[0079] Preferably, the control unit has a therapy control section configured to control the therapy laser module. In particular, the therapy control section is configured to control the therapy laser source. Preferably, the therapy control section is further configured to communicate with the scan control section, in particular to issue control commands to the scan control section. That is, the therapy control section can, if necessary, control via the scan control section which part of the tissue is to be treated with the therapy laser beam.

[0080] The control unit may preferably include a planning section configured to process input from the user interface and plan a treatment and / or measurement, for example, by calculating and planning the imaging and / or therapy scan patterns. The planning section may be configured to output planning and / or control data to the other functional sections of the control unit (measurement control section, therapy control section, planning section, scan control section). It may also be configured to receive data from the measurement control section and, if necessary, incorporate it into the planning. Furthermore, it may be configured to control the display device in order to output the depth measurement to a user. Finally, the planning section may be configured to process and execute commands from the user interface or to incorporate them into the planning.

[0081] The control unit is preferably integrated into the base station, in particular the entire control unit. Alternatively, the control unit can be provided separately from the base station, either wholly or partially (e.g., one or more of the aforementioned functional sections), and be connected to it for data transmission, or optionally connectable, e.g., via a wireless or wired connection or, for example, for transmitting treatment planning data, even via a portable storage device such as a memory stick or the like. Optionally, the control unit can also be connected to a third-party system, such as a hospital system, for data transmission, or optionally connectable.

[0082] The control device can be a single computing unit with a CPU, a GPU, RAM, a storage unit, and / or the like, which is or are programmed or configured to perform steps according to this disclosure. Alternatively, the control device can have several separate computing units configured to communicate with each other, i.e., which are connected to each other for data transmission or can be selectively connected, e.g., via a wireless or wired connection. The computing units can each have one or more of the functional sections. The computing units can each have a CPU, GPU, RAM, a storage unit, and / or the like, which is or are programmed or configured to perform steps according to this disclosure. The computing units can each have the functional sections of the control device individually or in groups. Character description

[0083] The present disclosure is described below with reference to preferred embodiments and the figures. These are exemplary and are not intended to limit the present disclosure. Fig. Figure 1 shows a schematic example of the setup of an ophthalmic laser system. Fig. 2a and Fig. 2b shows examples of therapy scan patterns. Fig. 3a and Fig. Figure 3b shows examples of imaging scan patterns. Fig. Figure 4 illustrates a first example of creating a depth image. Fig. Figure 5 illustrates a second example of creating a depth image.

[0084] Fig. Figure 1 shows an ophthalmic laser system 1 according to a preferred embodiment. The ophthalmic laser system 1 has a base station with a therapy laser module 2 and a tomographic measuring system 3.

[0085] The therapy laser module 2 has a therapy laser source 4, which generates a therapy laser beam 5. The therapy laser beam 5 is guided by a beam guidance device 6 to a laser output 7 of the ophthalmic laser system 1. At the laser output 7, the therapy laser beam 5 exits the ophthalmic laser system 1 to create incisions in at least partially transparent tissue. In this example, the at least partially transparent tissue is tissue from a patient's eye 8, specifically its cornea, but it could also be another type of tissue.

[0086] The beam guidance device 6 has various optical components configured to guide and shape at least the therapy laser beam 5. The beam guidance device 6 has x- and y-scanners, which form an xy-scan optic 9 and are controllable to deflect the therapy laser beam 5 and shift a focus of the therapy laser beam 5 in an x-direction and / or a y-direction, i.e., perpendicular to a beam direction of the therapy laser beam 5. Furthermore, the beam guidance device 6 has a z-scan optic 10, which is controllable to adjust a focus of the therapy laser beam 5 in the z-direction, i.e., in a depth direction of the patient's eye 8. The beam guidance device 6 may also include other components, e.g., for compensating for aberrations, for beam shaping, and the like, a collimator, etc.

[0087] According to the preferred embodiment, the tomographic measuring system 3 is an OCT, in particular a so-called swept-source OCT. The OCT has a measuring light source 11, in particular a measuring laser source, which emits a measuring beam 12 and a reference beam 13, in particular a reference laser beam. The reference beam 13 is guided from the measuring light source 11 to a detector 14. The measuring beam 12 is guided from the measuring light source 11 to a coupling point, where it is coupled into the beam guidance device 6, or can be selectively coupled into it. The coupling point can be, for example, at the xy-scan optics 9 or at the z-scan optics 10. Preferably, the measuring beam 12 is coupled into the beam guidance device 6 at a position upstream of or directly adjacent to the xy-scan optics 9, i.e., upstream of or adjacent to the first of the x- and y-scanners, so that the same beam guidance device 6 can be used to guide both the therapy laser beam 5 and the measuring beam 12., the measuring beam 12 runs parallel, preferably concentrically (in . between the coupling point and the laser output 7. Fig. 1 shown in parallel for better clarity), to a path of the therapy laser beam 5.

[0088] The measuring beam 12 is guided by the beam guide 6 to the laser output 7 and exits the ophthalmic laser system 1 there to detect structures in the patient's eye 8. If the measuring beam 12 is reflected back into the laser output 7 by structures in the patient's eye 8, it is guided back to the detector 14 by the beam guide 6. In the detector 14, the reflected measuring beam 12 interferes with the reference beam 13, thus enabling the detection of structures in the patient's eye 8. Any scattered light reflected from the therapy laser beam 5 does not interfere with the detection of the reflected measuring beam 12, or only minimally, because the measuring beam 12 and the therapy laser beam 5, or the reference beam 13, have different coherence lengths.

[0089] The ophthalmic laser system can be operated in different modes. In the first mode, the therapeutic laser beam 5 is active and the measuring beam 12 is inactive. In the second mode, the therapeutic laser beam 5 is inactive and the measuring beam 12 is active. In the third mode, both the measuring beam 12 and the therapeutic laser beam 5 are preferably active. When both the therapeutic laser beam 5 and the measuring beam 12 are active, they are directed simultaneously to the laser output 7 to exit and treat or measure the patient's eye 8. In this case, the measuring beam 12 is coupled into the therapeutic laser beam 5 at the coupling point. For example, the measuring beam 12 is shaped into a narrow beam by a pinhole mirror 15 and coupled centrally into the beam path of the therapeutic laser beam 5. In particular, the pinhole mirror 15 is designed as a deflecting mirror that deflects the therapeutic laser beam 5.In particular, the therapy laser beam 5 is wider at the coupling point than the therapy laser beam 5, so that the therapy laser beam 5 does not significantly impair the power of the therapy laser beam 5. That is, the therapy laser beam 5 has sufficient power for its function of creating cuts in the eye tissue even when the measuring beam 12 is active at the same time.

[0090] The laser output 7 has a holder for a treatment interface 16, which is transparent to the therapy laser beam 5 and the measuring beam 12. The treatment interface 16 can be attached to the holder interchangeably.

[0091] The base station of the ophthalmic laser system 1 has a base housing and a laser arm 17, which extends from the base housing and is preferably pivotable or movable via a first joint mechanism. The laser arm 17 is, in particular, adjustable between a treatment position in which the laser output 7 is directed towards the treatment of the patient's eye 8, and a passive position in which the laser arm 17 is pivoted away from the patient's eye 8.

[0092] The beam guide 6 is at least partially integrated into the laser arm 17. The coupling point is located, in particular, in the base housing. The therapy laser source 4 and the measurement laser source 11 are also located in the base housing. The laser output 7 is arranged at an end section of the laser arm 17. The coupling point, where the measurement beam 12 is coupled into the beam guide 6, is located in the base housing, i.e., between the therapy laser source 4 and the laser arm 17.

[0093] The ophthalmic laser system 1 according to the preferred embodiment further comprises a control unit 18, which is configured to control functional units of the ophthalmic laser system 1. The control unit 18 is connected via data transmission at least to the measuring light source 11 and the therapy laser source 4, the xy-scan optics 9, the z-scan optics 10, and the detector 14. The control unit 18 can be provided as a central processing unit, e.g., a CPU. Alternatively, the control unit 18 can be provided as a distributed system and can be provided in several networked computing units. The entire control unit 18 is preferably provided in or on the base station, i.e., physically connected to or attached to it.

[0094] In particular, the control unit 18 has a measurement control section 19, which is configured to control the tomographic measurement system 3, specifically to control the measurement light source 11 and to process data from the tomographic measurement system 3. The control unit 18 also has a therapy control section 20, which is configured to control the therapy laser module 2, specifically to control the therapy laser source 4 and, if applicable, the z-scan optics 10, as well as, if applicable, an AOM and various filters and shutters, which are not shown here. Furthermore, the control unit 18 may have a scan control section 21, which is provided for controlling the xy-scan optics 9 and, if applicable, the z-scan optics 10. The therapy control section 20 and the measurement control section 19 are connected to the scan control section 21 for data transmission in order to send control commands for executing therapy scan patterns 30 and 10, respectively.To output imaging scan pattern 31 to the scan control section 21 and / or to receive position data from it.

[0095] According to the preferred embodiment, the control unit 18 further comprises a planning section 22, which is configured to plan a therapy scan pattern 30 and an imaging scan pattern 31 and to output corresponding control data to the measurement control section 19, the therapy control section 20, and the scan control section 21. Furthermore, the planning section 22 can be configured to receive, process, and output the data from the measurement control section 19 as depth profiles or in the form of a two-dimensional (B-scan) or three-dimensional (C-scan) depth representation of the patient's eye 8 on a display device 23 of the ophthalmic laser system 1.

[0096] The ophthalmic laser system 1 further has at least one operating interface 24, which is configured for the input of data and / or commands by a user. For example, the operating interface 24 may include a keyboard, a joystick, a touch display, buttons, foot pedals, or the like. The planning unit 22 is then configured to receive and process commands from the operating interface 24, e.g., to take them into account when planning or processing the data of the measurement control section 19.

[0097] Fig. 2a and Fig. Figure 2b shows preferred examples of therapy scan patterns 25. For example, the therapy laser module 2 can be controlled to trace a spiral ( Fig. 2a). Alternatively, the therapy laser module 2 can be controlled to trace a meander or several parallel lines ( Fig. 2b). Other patterns are conceivable.

[0098] Fig. 3a and Fig. Figure 3b shows examples of imaging scan patterns 26. Preferably, an imaging scan pattern 26 has lines along which depth images 27 are to be created in the form of B-scans. Fig. Figure 3a shows an example imaging scan pattern which has radially extending lines. Fig. Figure 3b shows an example of an imaging scan pattern 26 with parallel lines, where the lines can be oriented differently (e.g. perpendicular, coincident or parallel) relative to a therapy scan pattern 25.

[0099] Fig. Figure 4 illustrates a first example of a therapy scan pattern 25, an imaging scan pattern 26, and a depth image 27 to be generated. The therapy scan pattern 25 follows a spiral along which sections are generated by the therapy laser module 2. In this example, the imaging scan pattern 26 has only a single line. Wherever the line of the imaging scan pattern 26 intersects the therapy scan pattern 25, the tomographic measurement system 3 records a depth profile 28, represented here by points. The depth profiles 28 are recorded, for example, immediately before, after, or during the generation of the spot. The depth profiles 28 are then combined to form the depth image 27 and output, e.g., via the display device 23.

[0100] Fig. Figure 5 illustrates a second example of a therapy scan pattern 25, an imaging scan pattern 26, and a depth image 27 to be generated. In this example, depth profiles 28 (represented as points on the therapy scan pattern 25) are acquired at regular temporal or spatial intervals along a cutting path. The cutting path is a path defined by the therapy scan pattern 25 and traced by the xy-scan optics 9 during tissue cutting. From the depth profiles 28, those that lie on the imaging scan pattern 26 are then selected (represented as white points) to generate the depth image 27. The remaining depth profiles 28 can be discarded or saved for documentation or later use.

[0101] Furthermore, it is from Fig.As can be seen in Figure 5, the imaging scan pattern 26 can have a larger radial extent than the therapy scan pattern 25. Areas of the imaging scan pattern 26 that extend beyond the therapy scan pattern 25 are referred to as missing areas 29. In the missing areas 29, for example, additional depth images 27 can be acquired during a switching phase in which a z-scan optic 10 is adjusted. Alternatively or additionally, the therapy scan pattern 25 can be modified (shown here by a dashed extension of the spiral therapy scan pattern 25) to acquire depth profiles 28 in the missing areas 29. Reference character list 1 ophthalmological laser system 2 therapy laser modules 3 Tomographic measuring system 4 Therapy laser source 5 therapy laser beam 6 Beam guidance device 7 Laser output 8 At least partially transparent tissue (eye) 9 xy-scan optics 10 z-scan optics 11 Measuring light source 12 Measuring beam 13 Reference beam (reference arm) 14 Detector 15-hole mirror 16 Treatment interface 17 Laser device arm 18 Control unit 19 Measurement control section 20 Therapy Control Section 21 Scan control section 22 Planning Section 23 Display device 24 user interface 25 therapy scan patterns 26 Imaging Scan Patterns 27 Depth view 28 Depth profile 29 Missing area QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 11 547 605 B2

[0006] US 2006 106 371 A1

[0007]

Claims

[1] Ophthalmic laser system (1) for producing cuts in at least partially transparent tissue with - a therapy laser module (2) with a therapy laser source (4) which is designed to generate a therapy laser beam (5); - a beam guidance device (6) which is configured to guide the therapy laser beam (5) to a laser output (7) and to focus it in a treatment area outside the laser output (7) in order to produce at least one cut in the at least partially transparent tissue, wherein the beam guidance device (6) has an xy-scan optic (9) which is configured to control a lateral deflection of the therapy laser beam (5); - a tomographic measuring system (3) with a detector (14) which is configured to detect light incident through the laser output (7) and reflected by structures of the at least partially transparent tissue from a measuring beam path in order to generate at least a depth profile (28) of the at least partially transparent tissue; and - a control device (18) which is configured to control the beam guidance device (6), in particular the xy-scan optics (9), and the tomographic measuring system (3), characterized by, that the xy-scan optics (9) is configured to deflect the measuring beam path between the laser output (7) and the detector (14) laterally, and the control device (18) is configured to control the tomographic measuring system (3) in such a way that it records the at least one depth profile (28), while the therapy laser module (2) and the beam guidance device (6) are controlled to perform a therapy step in which the at least one cut is produced in the at least partially transparent tissue. [2] Ophthalmic laser system (1) according to claim 1, wherein the control device (18) is further designed to assign each depth profile (28) and xy parameter, which represent an associated xy scan position at which the corresponding depth profile (28) was recorded, to each other as a data pair. [3] Ophthalmic laser system (1) according to claim 2, wherein the control device (18) is further designed to record multiple depth profiles (28) and to provide a corresponding number of corresponding data pairs in order to provide a depth scan (27) of the at least partially transparent tissue based on the data pairs, in particular in the form of a B or C scan or a number of A scans. [4] Ophthalmic laser system (1) according to claim 3, wherein the control device (18) is designed to - to control the tomographic measurement system (3) in such a way that it continuously or at regular intervals records the depth profiles (28) while the xy-scan optics (9) are controlled to produce at least one section, and - to select specific depth profiles (28) or data pairs for generating the depth recording (27) from the continuously or at regular intervals recorded depth profiles (28) or corresponding data pairs. [5] Ophthalmological laser system (1) according to claim 3, wherein the control device (18) is designed to control the tomographic measuring system (3) in such a way that it records the depth profiles (28) at predetermined xy scan positions, in particular corresponding to a position of the depth image (27) to be generated, or at predetermined times. [6] Ophthalmological laser system (1) according to claim 5, wherein the control device (18) is designed to trigger the acquisition of the depth profiles (28) by the tomographic measurement system (2) before reaching or crossing the predetermined xy-scan position in order to compensate for a delay between triggering and acquiring the depth profile (28). [7] Ophthalmic laser system (1) according to claim 1, wherein - between the generation of two spots of separated tissue by the therapy laser module (2) there is a switching phase in which a reconfiguration of the therapy laser module (2) and / or the beam guidance device (6) takes place, in particular while a z-scan optic (10) switches from a position of one of the spots to the position of another of the spots, and - the control unit (18) is designed to control the xy-scan optics (9) and the tomographic measuring system (3) in order to record at least one depth profile (28) during the switching phase. [8] Ophthalmic laser system (1) according to claim 1, wherein the control device (18), preferably in a planning phase in which a therapy scan pattern (25) is determined which is to be followed by the xy-scan optics (9) in the therapy step, is further designed to - to determine an imaging scan pattern (26) of depth profiles (28) which is required to provide at least one depth image (27), and - to identify at least one defective area (29) of the imaging scan pattern (26) which is not part of the therapy scan pattern (25) that is scanned during the generation of the section through the xy-scan optics (9). [9] Ophthalmological laser system (1) according to claim 10, wherein the control device (18) is further designed to control the tomographic measuring system (3) and the xy-scan optics (9) in order to record depth profiles (28) in the at least one defect area (29) during a switching phase and / or before and / or after the generation of the at least one section through the therapy laser module (2) is completed. [10] Ophthalmic laser system (1) according to claim 10, wherein the control device (18) is further designed to modify the therapy scan pattern (25) in the planning phase before the execution of the at least one cut and after the at least one defect area (29) has been determined, such that the at least one defect area (29) is wholly or partially covered by the modified therapy scan pattern (25). [11] Ophthalmic laser system (1) according to claim 1, wherein the at least partially transparent tissue is corneal tissue of a patient and / or a sample material. [12] Ophthalmic laser system (1) according to claim 1, wherein the tomographic measuring system (3) comprises an OCT or a confocal measuring system. [13] Computer program product for monitoring an ophthalmic laser treatment by an ophthalmic laser system (1) according to one of the preceding claims, comprising a program code which, when executed by the control device (18) of the ophthalmic laser system (1), performs the following steps: - Controlling the tomographic measuring system (3) of the ophthalmic laser system (1) such that it records depth profiles (28) while controlling the therapy laser module (2) of the ophthalmic laser system (1) to produce at least one cut in at least partially transparent tissue, whereby a position for recording the depth profile (28) is set by the xy-scan optics (9) of the ophthalmic laser system (1).

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