Temperature measuring arrangement and control device for a UV laser-based system for refractive error correction or for a femtosecond laser-based system, such a system, method for providing control data, and method for refractive error correction or for cross-linking or for laser-induced refractive index change

Abstract

The invention relates to a temperature measuring arrangement (100) and a control device (260) for a UV laser-based system for refractive error correction (200) or for a femtosecond laser-based system for corneal cross-linking (CXL) or for laser-induced refractive index change (LIRIC), which is configured to generate and emit laser light (221) and, using the laser light (221), process a processing region (290) of a sample (280) to be processed, and relates to such a system (200) and a method for providing control data. According to the invention, solutions from the prior art can be optimized in respect of speed and reliability by virtue of the temperature measuring arrangement (100) comprising at least one temperature sensor (107) for capturing a temperature signal (120) representing the temperature (T) of the processing region (290), wherein the temperature sensor (107) comprises at least one point sensor (107a) and an optical imaging system (105) imaging measurement light (110) onto the at least one point sensor (107a). The method according to the invention allows a rapid temperature-dependent adjustment of the control data (510) to changing processing conditions.

Description

[0001] Temperature measuring arrangement and control device for a UV laser-based system for correcting ametropia or for a femtosecond laser-based system, such a system, method for providing control data, and method for correcting ametropia or for crosslinking or for laser-induced changing of the refractive index

[0002] The invention relates to a temperature measuring arrangement and a control device for a UV laser-based system for correcting refractive errors, which is configured to generate and emit laser light and to process a processing area of ​​a sample to be processed with the laser light. The invention further relates to such a system, a method for providing control data for thermal optimization of a treatment using a UV laser-based system for correcting refractive errors, a method for providing and adapting control data, a computer program product, and a method for correcting refractive errors.

[0003] Lasers are preferred for operations such as refractive surgery on the human eye. These can be used to ablate tissue, for example to modify a curvature of the cornea. However, when tissue is ablated by laser ablation, the tissue in the treatment area and the tissue surrounding the tissue being treated also heats up. If tissue temperatures rise above a critical value, the coagulation temperature, tissue coagulation can occur. Since this can lead to complications such as haze formation in the case of an eye, an increase in tissue temperature above the coagulation temperature must be avoided. This can be taken into account before the actual treatment in a treatment plan or therapy plan, independent of the actual treatment.

[0004] It is desirable to perform the laser ablation process as quickly as possible, allowing for a compromise between a rapid processing process with high processing energies or pulse rates at a tissue temperature below the coagulation temperature. Furthermore, due to prevailing and varying environmental conditions or patient-specific effects, safety margins in the processing parameters are necessary, which can further slow down refractive error correction using laser ablation. This is the case because, in known systems, the safety margins slow ablation well before the coagulation temperature is reached in order to reduce heat input. Ablation can also be aborted if necessary.

[0005] Several solutions are known from the state of the art that can lower the temperature of a sample to be processed.

[0006] For example, it is possible to spatially and / or temporally optimize the firing sequence of a pulsed laser used for ablation so that a local flattening of the temperature profile can be achieved through heat transport in the tissue. The applied thermal energy thus diffuses away from the local treatment area into other areas of the eye and is distributed. Another option is to actively cool the eye, preferably the area being treated. Furthermore, the temperature profile in the tissue during irradiation can be numerically simulated and taken into account.

[0007] For example, US 2012 / 0 150 160 A1 presents a device for laser surgery with two operating modes, which are suitable for cutting the cornea or for rejoining it.

[0008] In US 11,197,781 B2, the temperature of the cornea is measured and, depending on this, the pulse repetition frequency, the pulse amplitude or the pulse duration is varied.

[0009] In US 9,301,876 B2, a thermal camera is used to measure the infrared radiation emitted by the cornea and, depending on this, the pulse energy is reduced or a different position is moved for irradiation.

[0010] In US 2004 / 0 236 392 Al, a machining area is cooled by an air flow, which can also be controlled by means of a thermal camera-based measurement of the machining area.

[0011] However, there is still room for further optimization of the above-mentioned solutions for monitoring the temperature of tissue in a sample being processed. It is desirable to accelerate existing devices and procedures for correcting refractive errors using refractive surgery. Such acceleration and the resulting shortened treatment time can be beneficial for both the surgeon and the patient and requires a time-optimized, pre-generated treatment plan containing control data representing the individual treatment steps.

[0012] The object of the present invention is therefore to provide a temperature measuring arrangement and a control device for a UV laser-based system for correcting ametropia, such a system, a method for providing control data and a method for correcting ametropia, which shorten the treatment time.

[0013] This object is achieved by the invention for the temperature measuring arrangement mentioned at the outset in that the temperature measuring arrangement comprises at least one temperature sensor for detecting a temperature signal representing the temperature of the processing area, wherein the temperature sensor has at least one point sensor and an optical imaging system that images the measuring light onto the at least one point sensor.

[0014] Furthermore, the above object is achieved by the invention for the UV laser-based system for correcting ametropia mentioned at the outset in that it comprises such a temperature measuring arrangement and a laser light source generating the laser light, a scanning device moving the laser light in a sample region and at least one control device, wherein the control device is designed to control the laser light source and / or the scanning device depending on the temperature signal of the temperature measuring arrangement.

[0015] The above object is achieved by the invention for the method for providing control data mentioned at the outset in that it comprises the following method steps: b) detecting measuring light emitted from a processing area of ​​a sample with a point-shaped temperature sensor, c) generating and providing a temperature signal representing the temperature of the processing area by the point-shaped temperature sensor, and d) creating control data, wherein the control data are created and provided as a function of the temperature signal.

[0016] The invention solves the above problem for the control device mentioned at the outset in that it comprises a temperature measuring arrangement according to the invention, wherein the control device is designed to control a laser light source of the system and / or a scanning device of the system as a function of the temperature signal of the temperature measuring arrangement, and wherein the control device is designed to control a UV laser-based system for correcting ametropia according to control data, wherein the control data were obtained by the method according to the invention for providing control data.

[0017] The computer program product according to the invention is designed, when executed on a UV laser-based system for correcting ametropia according to the invention, to carry out a method according to the invention for providing control data.

[0018] The devices and methods according to the invention can be improved by additional features. Unless otherwise stated, the additional features are each advantageous in their own right and can be combined with one another in any desired way. Additional features described solely for the device can be applied to a corresponding embodiment of the method according to the invention. Method features can also be applied to a corresponding device.

[0019] The processing area is the area to which the scanning device directs the processing beam path. The processing beam path is the path of the laser light predetermined by the optical elements in the system. Only when the method for correcting ametropia is carried out does the laser light propagate along the processing beam path, and the processing area corresponds to the area that is processed in a processing step. In such a processing step, the sample can be ablated, for example, by a laser. The sample can be an object to be processed, preferably an eye to be operated on, or a calibration or adjustment object. In this disclosure, the processing area is precisely the area where tissue will be ablated when a single laser pulse impinges on this area. The processing area can have a diameter of 1 mm, by way of example and not by way of limitation.In other terminologies, the processing area may be broader, for example, the area in which pulses ablate tissue over the entire processing duration. For the purposes of this disclosure, the latter area is referred to as the scanning area. The scanning area may, for example, be approximately one order of magnitude larger than the processing area.

[0020] Alternatively, the size of a measuring area of ​​the point temperature sensor or point sensor can also be larger than a spot diameter of the laser light of the UV laser-based system for correcting ametropia. Thus, the size of the measuring area can be defined not by the focus size of the laser light (processing light) of the laser light source, but can, for example, also have a diameter that is twice or three times as large as the spot diameter (also: diameter of the focus or double the beam waist) of the laser light of the UV laser-based system for correcting ametropia. Thus, the temperature of an area can be determined that is larger than the processing area, in particular twice or three times as large as the processing area defined by the laser light of the laser light source (and focusing optics, which are not explained in detail here).

[0021] The spot diameter used, i.e., the size of the focus or twice the beam waist, can preferably be between 0.4 mm and 2 mm. The spot diameter can particularly preferably be between 0.6 mm and 0.8 mm.

[0022] In general, a larger measuring range is associated with a less specific measurement, as the average is taken over a larger spatial area. The smaller the measuring range, the less information about the temperature in the immediate vicinity of the measuring area can be extracted from the measurement.

[0023] In the process for providing control data, planning takes place independently of the actual treatment. The control data can include coordinate data representing a treatment area. If a treatment area is addressed in the course of describing the process for providing control data, this is equivalent to the corresponding coordinate data and should not be understood as an area treated during the refractive error correction.

[0024] The solutions according to the invention thus have the advantage that the temperature in the processing area can be determined, i.e., calculated, simulated, or measured. According to the invention, a temperature in the areas surrounding the processing area is not calculated or measured. This makes it possible to make statements for the processing area only as to whether the critical temperature at which coagulation occurs has already been reached or, according to the control data, will be reached (immediately) with further processing. This statement can be used to answer the question of whether ablation can be performed by an additional laser pulse in the processing area. Ideally, the planning data can be generated depending on the measured temperature of the processing area.

[0025] This eliminates the need to calculate, record, or measure unnecessary temperature data from areas outside the processing area. This speeds up the corresponding processes and the corresponding equipment.

[0026] A further advantage is that the devices and methods are independent of varying parameters such as different tissue parameters, different ambient temperatures, and / or ambient humidity. Adaptation to changes in these parameters occurs indirectly only via the temperature measured in the treatment area. Furthermore, the planning data can be generated in such a way that, during execution, as much tissue as possible can always be removed from the treatment area before the coagulation temperature is reached.

[0027] A temperature signal provided within the UV laser-based vision correction system can, for example, be read by a controller as an input parameter. If the temperature signal is provided externally, it can be used, for example, to initiate active cooling and / or humidification. Cooling and / or humidification can be controlled based on the temperature signal.

[0028] In an advantageous embodiment of the temperature measuring arrangement according to the invention, it comprises at least one beam-deflecting and wavelength-selective optical element, wherein the wavelength-selective optical element is designed to combine a detection beam path of measuring light emitted from the processing area with a processing beam path of the laser light.

[0029] An alternative embodiment may provide for the detection light to be propagated via a second scanner system, analogous to the processing light. Such an embodiment may thus comprise two beam paths with respective scanners. Furthermore, it may be advantageous in this embodiment for the scanners of both beam paths to be synchronized with each other, so that the temperature is actually measured in the processing area in which processing will take place.

[0030] A combination or combining of the beam paths of laser light and measuring light can be an overlap of both beam paths, or the approximate overlap of both beam paths.

[0031] The wavelength-selective element can be a dichroic mirror or a beam combiner. The wavelength-selective element preferably separates the laser light from the measurement light, with the laser light preferably having a wavelength in the ultraviolet (UV) spectral range. In one possible embodiment, the laser light can be transmitted by the wavelength-selective element, and the measurement light can be reflected. This approach allows for simple implementation when the temperature measurement arrangement is retrofitted. Alternatively, and particularly in a redesign of a beam path, the opposite (laser light is reflected, measurement light is transmitted) may be easier to implement for optical and process-engineering reasons, since a coating design is less complex and easier to manufacture if the shorter-wavelength radiation component is reflected and the longer-wavelength radiation component is transmitted.The measurement light preferably has a wavelength in the near-infrared or infrared spectral range. Wavelengths from approximately 800 nm to a few micrometers are used, by way of example and not exclusively. Blackbody radiation emitted by the sample is particularly preferably used to determine the temperature. A maximum of this blackbody radiation can be between 3 pm and 7 pm, more preferably between 2 pm and 5 pm.

[0032] Since the beam path of the measuring light can be arranged collinearly with the beam exit of the laser light, the beam path of the laser light always ends in every processing area, from which the measuring light also propagates to the temperature measurement device. Both the measuring light and the laser light can be rasterized or scanned by the scanning device over the sample or the eye.

[0033] The wavelength-selective element is preferably a plane-parallel plate with a corresponding coating for transmitting or reflecting the spectral components to be separated. Further preferably, the wavelength-selective element can have an anti-reflection coating for the light to be transmitted, so that the light to be transmitted experiences negligible losses when passing through the wavelength-selective element.

[0034] By superimposing the two beam paths, a section-wise common beam path can be created.

[0035] In a further embodiment of the temperature measuring arrangement, it may further comprise an optical beam offset compensation element which is designed to compensate for a beam offset of the laser light (when the wavelength-selective element transmits the measuring light: of the measuring light) introduced by the wavelength-selective optical element.

[0036] This has the advantage that a lateral beam offset of the laser light can be compensated and, after passing the beam offset compensation element, continues to propagate in its original direction.

[0037] The measuring light also passes through the beam offset compensation element and is offset laterally so that the laser light and the measuring light propagate collinearly to each other

[0038] In a further embodiment, the beam offset compensation element can be a plane-parallel plate. Since the laser light and the measurement light have different wavelengths, different offsets are achieved when passing through the beam offset compensation element. In a further embodiment, this can be compensated for by arranging the beam paths for manipulation and detection offset from one another on the sample side of the wavelength-selective element, i.e. on a side of the wavelength-selective element facing the sample. The beam paths can thus run parallel to one another and be arranged at a distance from one another. Such an offset can be compensated for by the beam offset compensation element, which has a different refractive index for the different wavelengths and thus introduces a different offset.The resulting difference in the offset of both beam paths can correspond to the offset at the wavelength-selective element, so that on the sample side of the beam offset compensation element, the beam paths of the laser light and the measurement light are identical. Both beam paths can be collinear on the sample side of the beam offset compensation element.

[0039] The temperature sensor of the temperature measuring arrangement can comprise at least one point sensor and an optical imaging system that images the measuring light onto the at least one point sensor.

[0040] In particular, the temperature sensor comprises no more than 20, preferably no more than 16, more preferably less than or equal to 4 pixels, i.e., 1, 2, or 3 pixels. The temperature sensor is therefore not a thermal camera. Furthermore, the temperature sensor does not allow a spatially resolved temperature profile to be determined with a single measurement.

[0041] This is advantageous because a point sensor does not measure the temperature of the entire sample, but only a portion of it. Furthermore, the small number of pixels of the point sensor can significantly accelerate pixel readout.

[0042] In particular, this sub-area is the processing area, and a point-based temperature measurement of the sample can be performed. With the solution according to the invention, a high resolution of less than 1 mm, preferably between 0.5 and 2 mm, is possible. Furthermore, the point sensors according to the invention can be read at a readout rate of up to 500 Hz, preferably up to 1000 Hz, and more preferably at readout rates greater than 1000 Hz. Raster or scanning temperature determination can thus be carried out very quickly.

[0043] The point sensor is preferably a point-shaped photodetector, i.e., a photodetector with only one pixel. Point-shaped photodetectors with a few pixels, for example, up to 20 pixels, can also be used. The aforementioned imaging system can consist of a lens or comprise at least one lens. Preferably, the at least one lens is optimized for the NIR or IR range. The photodetector is preferably optimized in its spectral sensitivity, particularly preferably for the NIR or IR range with wavelengths between approximately 2 pm and 5 pm.

[0044] The UV laser-based system for correcting ametropia according to the invention comprises at least one embodiment of a previously described temperature measuring arrangement. In one embodiment, the temperature signal can be transferred from the temperature measuring arrangement to the control device, i.e. made available to it. The control device can be designed to read in the temperature signal, interpret it, and optionally convert it for further calculation. The control device can further be designed to use the temperature signal as a parameter of a calculation rule and to generate at least one control signal depending on the temperature signal. The control signal can be generated in particular before the start of a treatment. It can be stored in a volatile or non-volatile memory.Only when the control signal is transmitted, for example, from the control device to the laser light source and / or the scanning device, can the laser light source, the scanning device or both be controlled by means of the control signal.

[0045] Alternatively or additionally, the control device can provide the control signal externally to the system. To distinguish between them, the control signals can be referred to as internal control signals or external control signals.

[0046] The external control signals can, for example, be used to control parameters that cannot be changed by the system itself. This may require external devices such as a temperature controller, a humidity controller, or a spray controller, all of which can influence the ambient conditions of the sample. For example, a sample can be actively cooled by lowering the ambient temperature or by releasing a spray (mist) in the area around the sample.

[0047] The UV laser-based system for correcting refractive errors can be further improved by arranging the beam-deflecting, wavelength-selective optical element between the laser light source and the scanning device in a beam path of the laser light or by inserting it into the beam path of the laser light.

[0048] This has the advantage that the detection beam path always passes through the scanning device together with the processing beam path, and both beam paths are deflected or can be deflected together and simultaneously by the scanning device. This eliminates the need to readjust the detection beam path to a changed processing beam path. The temperature of the processing area at which the processing beam path deflected by the scanning device ends can therefore always be determined.

[0049] In a further advantageous embodiment, the scanning device can comprise at least one scanning mirror that reflects at least one wavelength range of the laser light and one wavelength range of the measurement light. This has the advantage that both the laser light and the measurement light can be redirected in the scanning device with the lowest possible losses.

[0050] In one embodiment, the scanning device can comprise a prism rotating around the processing beam path and a scanning mirror rotating around the prism together with the prism and positioned at an adjustable distance from the prism. In a further embodiment, the scanning device can comprise at least two scanning mirrors that can be rotated or tilted about different axes.

[0051] The UV laser-based system for correcting refractive errors can further comprise another beam-deflecting, wavelength-selective optical element. This optical element can be configured to spectrally separate the analysis light generated in the sample from the laser light and the measurement light. Preferably, the wavelength ranges of the laser light, the measurement light, and a wavelength range of the analysis light differ from one another. The system further comprises an analysis device for determining material data representing the material of the processing area, wherein the analysis device is configured to receive the analysis light, evaluate it, and provide the material data.

[0052] The further beam-deflecting, wavelength-selective optical element is preferably arranged between the laser light source and the scanning device, so that the analysis light and the corresponding beam path along which the analysis light propagates always originate from the processing area of ​​interest at the time.

[0053] In particular, the analysis light can be fluorescent light, which is generated by irradiating the sample with excitation light. Other wavelength ranges of analysis light are also conceivable.

[0054] The additional wavelength-selective optical element can be arranged in the beam path of the laser light, or in the beam path of the measurement light, which has already been separated from the laser light by the wavelength-selective optical element. In the latter case, the wavelength-selective optical element can preferentially reflect the analysis light and the measurement light, i.e., have a spectral band that reflects both wavelength ranges. Such an arrangement can be advantageous because it does not create any further beam offset in the beam path of the laser light.

[0055] The control device of the UV laser-based system for correcting refractive errors can be configured to vary, depending on the temperature signal, at least one processing parameter from the list of parameters, preferably stored in advance in the system for correcting refractive errors, comprising: coordinates of a selected processing area of ​​the sample; at least one beam parameter of the laser light source; and at least one environmental parameter.

[0056] This makes it possible to plan or carry out thermally optimized processing of a sample.

[0057] The control device may further comprise a data processing device which may be configured to vary at least one processing parameter from the list of parameters, preferably stored in advance in the system for correcting ametropia, as a function of the temperature signal.

[0058] The data processing device can allow processing parameters to be adapted to the temperature value depending on the temperature value and to store this change in the control data. Thus, the control data can represent processing steps such that, when executed during the actual treatment, the critical temperature in the processing area is not reached. Once executed, the control data thus allows for thermally optimized processing of a sample. The data processing device can be part of the control device or provided separately. Furthermore, the control device can be provided by hardware or software, or a combination of hardware and software.

[0059] The method for providing control data introduced above generates control data that can represent a treatment plan purely by way of example and not by way of limitation. The method therefore represents neither a surgical procedure nor a therapeutic procedure nor a cosmetic procedure, but rather a method that allows a surgical intervention to be planned based on the data obtained with this method.

[0060] Furthermore, the method for providing control data does not include any method step that imposes or produces a surgical, therapeutic, or cosmetic effect on the human or animal body. The control data generated by the method merely represent one or more instructions for action.

[0061] In the method, in particular, only the temperature of the processing area is recorded and / or provided. Recording the temperature of surrounding areas is avoided, so that only temperature information for the processing area is available. The temperature can thus be recorded quickly and at a high readout rate, for example, at 500 Hz, preferably at a readout rate greater than 500 Hz, more preferably greater than 1000 Hz. Readout can be further accelerated by using point sensors or point-shaped sensors with a few pixels (1 to 20) to generate the temperature signal.

[0062] The control data generated in the process can preferably be stored. This storage can be temporary or permanent. Storage has the advantage that the generated control data can be accessed at any time.

[0063] The control data can represent a processing plan, which in turn can comprise a schedule of individual processing steps. The processing steps can represent a treatment sequence. Likewise, the control data can represent a single treatment instruction. If the control data represents multiple processing steps, these can be sorted chronologically according to the time of execution directly in the control data. Alternatively, the control data can comprise sequence data that represents the sequence or order of the different processing steps. This sequence data makes it possible, for example, to include a processing step, which can preferably be referenced using a pointer or a reference, multiple times in the sequence by reference. Purely as an example, the recording of a temperature can occur multiple times or continuously in the treatment sequence. The size of the control data can be fixed or variably expandable.The data format of the control data is irrelevant and can vary from system to system and may, for example, be supplemented by parity or check bits or encryption.

[0064] Each processing step can be represented by a data array, whereby several data arrays can form a data set of the control data. Each data array can further have a plurality of data segments in which, purely by way of example and not by way of limitation, a parameter, its initial value, its value to be set or a necessary change to the parameter can be stored. Each data array can comprise any number of so-called flags, i.e. individual bits that can be set by writing a 1 to this bit. Thus, purely by way of example, each data array, in particular each data segment, can comprise an "activated" flag. If this flag is not set, the corresponding parameter represented by this data segment can be ignored when the control data is executed, so that it is retained unchanged and not changed.

[0065] In a further advantageous embodiment of the method according to the invention for providing control data, this can further comprise the method steps c1) comparing the temperature represented by the temperature signal with a threshold value representing a maximum permissible threshold temperature; and c2) recording threshold value data in the data set, wherein the threshold value data represents at least the information as to whether the temperature signal exceeds the threshold value; wherein method steps c1) and c2) are carried out chronologically after method step c). Such a comparison of temperature signal and threshold value can be carried out in a calculation before the treatment.

[0066] The control data thus contains information about whether the threshold temperature has been mathematically reached in the processing area. This has the advantage of preventing unwanted damage to the tissue of a sample that is to be treated based on the control data. To prevent this, the control data can contain instructions that can directly or indirectly prevent the threshold temperature from being reached.

[0067] The threshold value data can also be represented by a single bit. If this is set, then, for example and without limitation, the relationship (temperature of the processing area > threshold temperature) can prevail in the processing area. Furthermore, in another embodiment, data can also be stored which represents the temperature difference between the temperature in the processing area and the threshold temperature, i.e. a relative indication of how many degrees the threshold temperature has been exceeded. This can be used to decide in the control data which measures are to be taken. For example, the data set can contain data representing an active action instruction if the threshold temperature has been exceeded by a certain value, or data representing a passive action instruction if the excess is slight, for example and without limitation < 0.5 °K.

[0068] It is also advantageous to implement the methods described above as test methods. For example, a test specimen whose temperature is adjustable and / or monitorable can be introduced into a processing area, and the temperature of the specimen can be determined using the method. As soon as the temperature of the specimen reaches a predetermined threshold temperature, the generated control data contains information about the exceedance. This allows testing to determine whether the method reliably detects when the threshold temperature has been reached, can indicate this exceedance based on the control data, and, if applicable, displays a correct temperature difference.

[0069] In a further embodiment of the method according to the invention for providing control data, this can further comprise the following method steps: a) sending control signals to a scanning device, wherein the control signals represent a sequential approach to a predetermined plurality of spatially separated processing areas by means of the scanning device; and c3) incorporating matrix data into the control data, wherein the matrix data represent at least a sorting of the plurality of processing areas according to the temperature of the respective processing areas, wherein method step a) is carried out chronologically before method step b) and method step c3) is carried out chronologically after method step c).

[0070] This makes it possible to measure a sample before processing and, for example, determine its temperature distribution. Furthermore, based on the temperature distribution, it is possible to determine at which processing positions or in which sequence of possible processing positions processing may be advantageous. The temperature distribution can thus serve as a decision-making aid for planning a processing operation that can be carried out as quickly as possible and with the same number of processing steps, with the lowest possible temperature reached after each processing step.

[0071] Such a method can be considered a thermal measurement method, which is not coupled to subsequent ablation or processing of a body. The thermal measurement method can comprise all of the method steps described in this disclosure in any combination.

[0072] A corresponding device, i.e., an arrangement comprising at least a scanner and a point sensor, can therefore be used as a thermal measuring instrument without the laser operating in ablation mode. Such a device can be provided autonomously and separately, or as part of a laser system. Such a thermal measuring instrument can have all of the device features of the temperature measuring arrangement or the UV laser-based system for correcting ametropia described in this disclosure. The use of such a thermal measuring instrument is advantageous because it can be used to create a thermal map (temperature map) of the cornea before the start of the ablation, on the basis of which a decision can be made, purely by way of example, as to whether and / or where and / or when the ablation can be started.

[0073] In addition, such thermal measurements -- as mentioned above -- can be performed during ablation as a control.

[0074] It is also conceivable to determine a local temperature in the vicinity of a planned processing area for the ablation using the described method or the described temperature measuring arrangement. For example, it is conceivable to carry out or sample three “measurement shots” or temperature measurements in a purely exemplary annular environment of a processing area defined as the target processing area in order to determine a local temperature of the target processing area. In other words, in the above-mentioned example, three processing areas defined as auxiliary processing areas can be selected which are arranged around the target processing area, preferably in a ring around it, more preferably equidistant from one another, in order to approximate a temperature of the target processing area, i.e. to estimate it from the (in the present example) three measurements of the temperature of the auxiliary processing areas.It is also conceivable that any number of auxiliary machining areas are selected and their temperature is measured in order to determine a temperature of a target machining area surrounded by these auxiliary machining areas.

[0075] This method can also be used as a test procedure by using a specimen with a known temperature distribution or temperature profile. This specimen can be used to verify the correct determination of the temperature distribution and, on the other hand, to plan a processing sequence based on the temperature distribution.

[0076] Process step c3) can be carried out directly after process step c) or after process step c2).

[0077] Preferably, the spatially separated processing areas are not adjacent to each other. Moving to a specific processing area means adjusting the scanning unit to the corresponding processing area.

[0078] The method can be further improved by reading out previously stored material data and / or reading in material data entered by a user and / or determining material data and further comprising the following method step: c4) recording the material data and / or recording parameter change data calculated from the material data in the control data, wherein the material data and / or the parameter change data represent at least the information about a material-dependent processing parameter and / or about at least one parameter change necessary to achieve a constant processing parameter, wherein method step c4) is carried out chronologically after method step c).

[0079] This embodiment of the method thus makes it possible to adapt the control data to a material and / or material properties and / or a material change of the sample to be processed and to take into account any influence of the material and / or its properties on the processing. Through such an adaptation, it is possible to generate the control data in such a way that, when executed, they allow the sample to be processed, in particular the processing area, to be processed as shortly as possible before the coagulation temperature is reached. The material data can, for example, represent an ablation rate and / or a coagulation temperature for the corresponding material or tissue to be processed. The material data can also represent a water content of the tissue and, in particular, its degree of dehydration (for example, of the cornea when it is exposed after cutting a flap).

[0080] The material data thus allows a reliable forecast of the expected machining progress with given parameters, while the parameter change data makes it possible to compensate for changes in the machining progress due to changes in the material data. This compensation can be achieved, for example, by adjusting additional parameters that also influence the machining progress to reflect changes in the material data.

[0081] If, purely by way of example and not by way of limitation, the drying of the tissue in the processing area occurs approximately linearly, a correspondingly complementary linear change in one or more other parameters can keep the processing speed constant despite this drying. The drying can thus be incorporated into the planning of a vision correction and represented by the control data.

[0082] The material or fabric type can be known in advance. This can also be read from a memory. Alternatively or additionally, the material data can be determined by previously modeling the processing areas and the removal rate already achieved there. In addition to varying removal rates, a permissible maximum temperature can also be material- or fabric-dependent and vary for different processing areas.

[0083] In one embodiment, it is possible to determine the material data by measurement. For example, excitation light can be irradiated onto the treatment area, which stimulates fluorescence in the tissue there. The resulting fluorescent light, generally analytical light if it was not generated by fluorescence, for example, can be spectrally separated from the measurement light and detected using an additional wavelength-selective optical element. Depending on the material and / or composition and / or degree of drying, the fluorescence signal can change, and the corresponding parameters can be extracted from it. By providing data representing these parameters, it is possible to adapt the control data to a change in the material or its properties in the planning phase prior to the refractive error correction.

[0084] Purely by way of example and not by way of limitation, it may be known during the planning phase that a transition from material A to material B will occur. During this transition, the ablation rate (in terms of unit length or volume per processing pulse) may decrease by 10%. To counteract this effect, the repetition rate of the processing laser can be increased by 10%, also purely by way of example. The repetition rate of the processing laser can be represented by the control data.

[0085] The above example is for explanatory purposes only, as several parameters can change depending on the material being processed.

[0086] Process step c4) is carried out after process step c), ie optionally the above-mentioned process step c2) or process steps c1) to c3) can be carried out before process step c4).

[0087] In the previously described embodiments of the method for providing control data, reaching a threshold temperature (which may correspond to the coagulation temperature) was avoided according to the control data. However, this limitation in the processing of a sample can be circumvented under certain conditions. Thus, while maintaining strict safety limits, it is possible to heat areas of a sample that are to be removed in subsequent processing steps up to and beyond the coagulation temperature. Although the corresponding area of ​​the sample is damaged in these cases, this damaged area is removed during the further course of processing.

[0088] A corresponding embodiment of the method according to the invention for providing control data comprises e1) reading out pre-stored sample volume data and / or reading in sample volume data provided by a user; e2) reading out pre-stored ablation data and / or reading in ablation data provided by a user, wherein the ablation data represents an ablation rate; e3) determining, preferably calculating, a total number N of processing steps based on the sample volume data and the ablation data; e4) determining a difference between the total number N of processing steps and a predetermined number Nnorm of processing steps in the normal range, wherein in the normal range according to control data, a predicted temperature of the sample is always lower than a maximum permissible temperature of the sample represented by a threshold value;and e5) including expiration data in the control data, wherein the expiration data comprises a temporal sequence of (NN; n orm) outside the normal range and N nO rm represent the processing steps to be performed within the normal range. This embodiment of the method for providing control data has the advantage that processing of a sample can be carried out even more quickly, while at the same time avoiding damage to remaining tissue, i.e., tissue that is not to be ablated.

[0089] The sample volume data can represent a volume of the sample to be ablated, i.e., removed. This sample volume data can be read out (preferably from a memory) or made available. This can be done, for example, after remote planning, preferably via an ophthalmological data management system.

[0090] The ablation data represent how much material can be removed / ablated with a single pulse or shot of a processing laser. This ablation data can be determined, for example, using the previously described embodiment of the method for providing control data. The ablation data are preferably calculated theoretically and can represent a calculated ablation rate.

[0091] The total number N indicates how many pulses / shots are required to completely remove the material to be ablated according to the control data. Preferably, the extent of the sample volume along a propagation direction of the laser light, i.e., the thickness of the material to be ablated, can be decisive here. In a simple embodiment, for example, the thickness of the sample volume represented by the sample volume data is divided by the ablation rate, resulting in the total number N of processing steps.

[0092] However, before the sample volume has been completely processed in its thickness, the material can also be damaged according to the control data resulting from this design of the planning procedure, since the previously damaged tissue can be ablated using the remaining ablation pulses within the normal range. Tissue damage is thus only accepted for those areas that are to be removed anyway according to the control data. However, this is only possible if the total number N exceeds the number N nO rm exceeds.

[0093] The number (N- N nO rm) of processing steps can thus be released from a limitation of the temperature of the processing area. In the control data, these (NN nO rm) processing steps as the N nO rm processing steps must be marked ahead of time.

[0094] From previous measurements, it can be known which sample volume needs to be removed for a refractive error correction. The ablation rate can also be known. Thus, this embodiment of the method for providing control data allows the planning of a refractive error correction that can be performed more quickly than a refractive error correction in which the threshold temperature is not exceeded, even in areas that are being ablated anyway. In the method according to the invention for providing control data, the control data generated by the method can represent at least one treatment sequence and / or at least one treatment instruction from the following list:

[0095] (1) Varying parameters of the laser light depending on exceeding the threshold temperature to reduce the heat input into the sample; and / or

[0096] (2) Varying parameters of the laser light depending on the material data and / or depending on the parameter change data; and / or

[0097] (3) Determining the processing area of ​​the plurality of spatially separated processing areas with the lowest temperature represented by the temperature signal and declaring this processing area as the start processing area; and / or

[0098] (4) Determining a sequence of the processing areas, whereby the individual processing areas are sorted according to their determined temperature (preferably in ascending order), and / or

[0099] (5) Carrying out (N-Nnom) processing steps outside the normal range and subsequently carrying out N nO rm processing steps within the normal range.

[0100] The above numbering is purely exemplary and serves only to distinguish between them.

[0101] The control data can thus contain the above treatment sequences or treatment instructions in any combination and / or sequence, so that when the control data is executed, a sample can be processed according to the control data.

[0102] Regarding the treatment instructions (5), the N nO rm processing steps within the standard range either directly after the (N-Nnorm) processing steps outside the standard range, or after a delay during which the sample cools down by diffusion of heat within it.

[0103] The control device can be configured to provide action data representing action instructions of a UV laser-based system for correcting refractive errors based on control data readable by the control device. Thus, the control device can be implemented purely in software and, for example, executed locally remotely from the UV laser-based system for correcting refractive errors, for example, on a remote workstation or in a cloud. Such a control device can provide the action data in a format that can be read and interpreted, purely for example, by a controller of the laser light source and / or the scanning device.

[0104] In an advantageous embodiment of the computer program product, it can be executed on any computer, any computing unit, or any integrated circuit (FPGA; field programmable gate array) and is designed to carry out a method comprising the following method steps: receiving a temperature signal that represents the temperature of the processing area determined by means of a point-shaped temperature sensor; and creating control data, wherein the control data are created and provided as a function of the temperature signal.

[0105] In further embodiments of the computer program product executable on any computer, this comprises: the method steps a) and c3); and / or reading out previously stored material data and / or reading in material data entered by a user and / or determining material data and the method step c4); and / or the method steps e1) to e5); and / or the method steps c1) and c2).

[0106] In these embodiments of the computer program product, all process steps can be carried out completely by general data processing means.

[0107] Each of the above-mentioned embodiments of the method for providing control data can provide control data to be used in a method for correcting ametropia.

[0108] The method for correcting refractive errors in a human eye comprises the following method steps: e6) detecting measuring light emitted from a processing area of ​​the human eye with a point-shaped temperature sensor, e7) generating and providing a temperature signal representing the temperature of the processing area by the point-shaped temperature sensor, e8) creating control data representing process steps of the refractive error correction, wherein the control data are created as a function of the temperature signal, and e9) controlling a UV laser-based system for correcting refractive errors and carrying out the refractive error correction on the human eye according to the control data.

[0109] In particular, the control data can be determined and / or corrected according to a method for providing and adapting control data during a vision correction and / or provided for controlling the laser light source and / or for controlling the scanning device. In the method for providing and adapting control data, a first processing step is carried out according to initial control data. The initial control data can be provided in advance, for example, stored. This processing step comprises at least the provision of one laser pulse from a laser light source, which processes a processing region of a sample region according to the initial control data. After this step, new control data are provided according to a method for providing control data, and the initial control data are adapted based on this.

[0110] The method for correcting refractive errors can also be applied to other types of human or animal tissue, such as skin layers, muscle tissue, or bone tissue. It can also be applied to artificial tissue or tissue removed for testing or training purposes (i.e., in vitro). For this purpose, the system's UV laser can be replaced by other suitable laser types, such as infrared or short-pulse lasers, whose wavelength and / or pulse energies are adapted to the specific tissue to be treated. Likewise, the spectral range of the measuring light can be shifted for different tissues (bone tissue, for example, can be heated more intensely). Accordingly, the optical system that images the measuring light and the temperature sensor can be adapted to the changed spectral range of the measuring light.

[0111] This makes it possible to make adjustments to the control data during the refractive error correction process depending on the parameters of the treatment area, and to always perform the refractive error correction in a time-optimized manner and under thermally optimized conditions, i.e., without exceeding the maximum permissible temperatures. Thus, the information obtained from the process can be used to directly decide on a possible further course of action in an intermediate treatment step.

[0112] For example, using a very fast-reading point temperature sensor, it is possible to measure the temperature of the currently processed area after processing, save it, and adjust the parameters of the next processing step, preferably the parameters of the immediately following processing step, if the measured temperature exceeds a limit. This makes it possible to determine and evaluate the temperature of the processing area even between two pulses from the laser light source.

[0113] It is also possible, after performing a certain number of processing steps, for example, the ablation of a layer of the cornea defined by individual processing areas, to measure the temperature at various processing areas (preferably these are not adjacent to each other) and to ablate another layer of the cornea, starting with the processing area with the lowest temperature. For this purpose, after ablating a layer of a sample, e.g., the cornea, the method for providing control data can be used. This method comprises sequentially approaching a predetermined number of spatially separated processing areas and incorporating matrix data into the control data in order to determine a temperature distribution of the sample. The next layer of the sample can then be ablated based on the determined temperature distribution according to adapted control data.Advantageously, in this processing step, processing starts at the processing area that has the lowest temperature in the temperature distribution. Geometric aspects of the temperature distribution can also be taken into account when planning further processing; for example, time-efficient scan patterns can be taken into account during preparation or when adapting the control data. It is also possible to save the temperatures of the individual processing areas (e.g. internally) and thus create a "map" of the temperature distribution (temperature map). This map can also be continuously updated. Such an embodiment of the method for providing and adapting control data can be used in efficient algorithms for determining the location / position of the next pulses, for example in adaptive sorting processes.

[0114] Further aspects of the invention relate to a non-volatile storage medium on which a computer program product according to the invention is stored. This storage medium can be an optical, magnetic, or electrically operating storage medium, for example a CD, DVD, Blu-ray, HDD, SDD, RAM, ROM, EPROM, or a similar storage medium.

[0115] Alternatively, a temperature measuring arrangement for a femtosecond laser-based system for corneal crosslinking (CXL) or for laser-induced change of the refractive index (LIRIC: laser-induced refractive index change) is conceivable, wherein the femtosecond laser-based system is designed to generate and emit laser light and to process a processing area of ​​a sample to be processed with the laser light, wherein the temperature measuring arrangement comprises at least one temperature sensor for detecting a temperature signal representing the temperature of the processing area, and wherein the temperature sensor has at least one point sensor and an optical imaging system imaging the measuring light onto the at least one point sensor.

[0116] Such a temperature measuring arrangement can further comprise at least one beam-deflecting and wavelength-selective optical element for the corresponding wavelength range of the femtosecond laser, wherein the wavelength-selective optical element can be designed to combine a detection beam path of measuring light emitted from the processing region with a processing beam path of the laser light.

[0117] Such a temperature measuring arrangement may further comprise an optical beam offset compensation element which is designed to compensate for a beam offset of the laser light introduced by the wavelength-selective optical element.

[0118] A corresponding femtosecond laser-based system for corneal crosslinking or for laser-induced changes in the refractive index can thus comprise the following devices: a temperature measuring arrangement as described above; a femtosecond laser light source generating the laser light; a scanning device moving the laser light in a sample region; and at least one control device, wherein the control device can be configured to control the femtosecond laser light source and / or the scanning device depending on the temperature signal of the temperature measuring arrangement.

[0119] Such a femtosecond laser-based system for corneal crosslinking or for laser-induced change of the refractive index can further arrange a beam-deflecting, wavelength-selective optical element between the femtosecond laser light source and the scanning device in a processing beam path of the laser light or can be provided such that it can be introduced into the processing beam path of the laser light.

[0120] Such a scanning device of the system described above may comprise at least one scanning mirror which reflects at least one wavelength range of the laser light and one wavelength range of the measuring light.

[0121] Such a femtosecond laser-based system for corneal crosslinking or for laser-induced changing of the refractive index can further comprise a further beam-deflecting wavelength-selective optical element which is designed to spectrally separate analysis light generated in the sample from the laser light and the measuring light, wherein the wavelength ranges of the laser light and the measuring light and a wavelength range of the analysis light differ from one another, and wherein the system further comprises an analysis device for determining material data representing a material of the processing area, wherein the analysis device is designed to receive the analysis light, evaluate it and provide the material data.

[0122] The femtosecond laser-based system can also be designed to vary at least one processing parameter, preferably stored in advance in the system for correcting refractive errors (as described above for the UV laser-based system), depending on the temperature signal.

[0123] The method described herein for providing control data for thermal optimization of a treatment using a UV laser-based system for vision correction can be applied alternatively to thermal optimization in corneal crosslinking or in laser-induced changes in the refractive index, whereby in both cases it comprises the same method steps, optionally adapted to the femtosecond laser source.

[0124] All variations of the method described herein for providing control data for thermal optimization of a treatment using a UV laser-based system for correcting refractive errors are also transferable to the method for providing control data for thermal optimization in corneal crosslinking or in laser-induced changes in the refractive index.

[0125] Likewise, the described method for providing and adapting control data for the UV laser-based system can be transferred to a femtosecond laser-based system.

[0126] Furthermore, a control device for a femtosecond laser-based system for corneal crosslinking or for laser-induced changes in the refractive index is conceivable. This can comprise a temperature measuring arrangement as described above, wherein the control device is configured to control a femtosecond laser light source of the system and / or a scanning device of the system as a function of the temperature signal of the temperature measuring arrangement, and wherein the control device is configured to control a femtosecond laser-based system for corneal crosslinking or for laser-induced changes in the refractive index according to control data obtained by a method for providing control data described herein.

[0127] Furthermore, a method for corneal crosslinking or laser-induced refractive index changes in a human eye is conceivable. This comprises the following process steps:

[0128] Detecting measuring light emitted from a processing area of ​​the human eye with a point-shaped temperature sensor;

[0129] Generating and providing a temperature signal representing the temperature of the processing area by the point-shaped temperature sensor;

[0130] Creating control data representing process steps of corneal crosslinking or laser-induced change of the refractive index, wherein the control data are created as a function of the temperature signal; and

[0131] Controlling a femtosecond laser-based system for corneal crosslinking or laser-induced refractive index change and performing corneal crosslinking or laser-induced refractive index change on the human eye according to the control data.

[0132] Likewise, a computer program product is conceivable which, when executed on a femtosecond laser-based system for corneal crosslinking or for laser-induced changing of the refractive index, is designed to execute a method for providing control data for corneal crosslinking or for providing control data for laser-induced changing of the refractive index.

[0133] Crosslinking and laser-induced changes in the refractive index of comeal tissue refer to the treatment of comeal tissue with low-energy plasma. These methods utilize multi-photon absorption of 2 to 6 photons. This allows the surrounding tissue to heat up sufficiently, particularly in volume treatments where multiple pulses are applied. Laser-induced changes in the refractive index (LIRIC) and comeal crosslinking (CXL) represent two possible applications of such treatment with low-energy plasma. Another preferred embodiment of CXL is plasma-mediated agent-free CXL.

[0134] Typical wavelengths for treating corneal tissue with low-energy plasma that have proven preclinically effective are, for example and not limited to, 400 nm, 405 nm, or 810 nm for LIRIC, or more generally, 800 nm to 1100 nm. Typical wavelengths for CXL are, for example and not limited to, 525 nm or 760 nm. The aspects of the present invention will be explained in more detail below with reference to the accompanying drawings. The drawings show possible exemplary embodiments of the present invention purely by way of example, wherein the described features can be combined with one another or omitted as desired. Identical features or features with the same function are further identified by the same reference numerals.Repetitive descriptions of features are avoided, so that explanations of features written in previous figures can also be transferred to other figures, unless differences are explicitly pointed out.

[0135] They show:

[0136] Fig. 1 is a schematic representation of the temperature measuring arrangement;

[0137] Fig. 2 is a schematic representation of an embodiment of the UV laser-based system for correcting refractive errors according to the invention;

[0138] Fig. 3 is a schematic representation of a further embodiment of the UV laser-based system for correcting refractive errors according to the invention;

[0139] Fig. 4 is a schematic representation of a further embodiment of the UV laser-based system for correcting refractive errors according to the invention;

[0140] Fig. 5 is a schematic representation of the method for providing control data;

[0141] Fig. 6 is a schematic representation of part of an embodiment of the method for providing control data; and

[0142] Fig. 7 is a schematic representation of part of a further embodiment of the method for providing control data.

[0143] Fig. 1 shows a possible exemplary and non-limiting embodiment of the temperature measuring arrangement 100 according to the invention. In the illustrated embodiment, the temperature measuring arrangement 100 comprises a housing 101 and an inlet opening 103 provided in this housing 101, through which measuring light 110 can be coupled into the housing 101. Furthermore, the temperature measuring arrangement 100 comprises a temperature sensor 107.

[0144] The temperature sensor 107 has an optical imaging system 105 and a point sensor 107a. In the embodiment shown, the temperature sensor further comprises an electrical circuit board 107b, which, purely schematically, has several integrated circuits and conductor tracks and is designed to operate and / or evaluate the electrical signals of the point sensor 107a.

[0145] The point sensor 107a is preferably a photodetector. The point sensor 107a preferably comprises a single pixel 107c. This allows the point sensor 107a to be read very quickly, which in turn enables a high readout frequency. The temperature sensor 107 generates a temperature signal 120, which represents a temperature T of a processing area of ​​a sample to be processed. The temperature signal 120 can be provided via a signal line 101a from the temperature measuring arrangement 100 and is shown purely schematically in Fig. 1.

[0146] In other embodiments, the point sensor 107a can have an array of 2x2, or 3x3, or 4x4 pixels 107c, wherein, according to the invention, these pixels 107c are configured to determine the temperature signal 120 and not to spatially resolve a temperature distribution. The temperature measuring arrangement 100 is thus not a thermal camera, but rather a point-measuring arrangement for determining the temperature T. An array of multiple pixels 107c can make it possible to fully utilize the focus of the measuring light 110 for determining the temperature signal, since the achievable spot diameters in the focus are wavelength-dependent, and larger wavelengths are associated with larger spot diameters.

[0147] In the illustration shown, the inlet opening 103 is merely a recess 103a, which in other embodiments can also be a window protecting an interior region 109 of the temperature measuring arrangement 100 from external influences such as dust and / or liquid. The measuring light 110 is, in particular, infrared or near-infrared light 110a, which is actively emitted by a sample based on its temperature T, without the need for external manipulation of the sample.

[0148] The optical imaging system 105 shown in Fig. 1 is purely exemplary of a lens 105a designed, i.e., optimized, for the infrared or near-infrared light 110a. This lens 105a focuses the measurement light 110 onto the point sensor 107a. The focus of the measurement light 110 is preferably completely imaged onto the pixel or pixels 107c.

[0149] In other (not shown) embodiments of the temperature measuring arrangement 100, the optical imaging system 105 can also be designed as a mirror or a combination of at least one mirror and at least one lens.

[0150] A UV laser-based system for correcting vision defects 200 is described below with reference to Figs. 2 to 4. Basic aspects of the UV laser-based system for correcting vision defects 200 are identical for all three embodiments shown in Figs. 2, 3, and 4, although the temperature measurement arrangement 100 used differs for the three embodiments. The schematic illustrations of different embodiments of the UV laser-based system shown in Figs. 2 to 4 can be transferred to embodiments not shown of a femtosecond laser-based system for corneal crosslinking or for laser-induced changes in the refractive index. The basic structure of the system shown can be adopted, with any necessary adaptation of reflective and transmissive elements of the laser system being known when transitioning from a UV laser-based system to a femtosecond laser-based system.

[0151] Since the temperature measuring arrangement 100 operates in a predetermined wavelength range that is independent of the processing laser, no modification to the temperature measuring arrangement 100 is necessary per se. Only elements such as a wavelength-selective optical element 293 (described below), which interact with the processing laser, require a corresponding adaptation.

[0152] The UV laser-based system for correcting refractive errors 200 is shown schematically and comprises a temperature measuring arrangement 100 according to the invention, a laser light source 220 which generates laser light 221, a scanning device 240 which is designed to move the laser light 221 in a sample region 281 of a sample 280, and a control device 260.

[0153] The control device 260 is connected to the laser light source 220, the scanning device 240 and the temperature measuring arrangement 100 and is particularly designed to control the laser light source 220 and / or the scanning device 240 depending on the temperature signal 120 of the temperature measuring arrangement 100.

[0154] The laser light source 220 comprises a UV laser, corresponding optical elements for directing its radiation, and a laser controller, which will not be discussed further here. Since the laser light source 220 provides laser light 221 in the ultraviolet spectral range, the transmission of the same preferably occurs along a processing beam path 223 whose immediate surroundings are evacuated. The vacuum tubes, corresponding windows, and other necessary vacuum technology required for this purpose are not shown in the schematic representation of Figures 2 to 4 for the sake of clarity. The processing beam path 223 is represented by a dot-dashed line.

[0155] In the illustrated embodiment, the scanning device 240 comprises two scanning mirrors 241, which execute a rotational movement 243 about a respective rotational axis 245. The rotational axes 245 of the two scanning mirrors 241 are preferably oriented perpendicular to one another, so that the combination of the rotational movements 243 of the two scanning mirrors 241 makes it possible to move the processing beam path 223 within a scanning area 247 on the sample 280. The scanning area 247 results from a first deflection direction 249, which extends into the plane of the drawing, and a second deflection direction 251. After alignment of the sample 280, the scanning area 247 preferably corresponds to the sample area 281.

[0156] Fig. 2 also shows an alternative scanning device 253, which comprises a deflection prism 255, which performs a rotational movement 243, and a scanning mirror 241, which performs a linear movement 257. Fig. 2 shows three possible positions of the processing beam path 223 on the sample 280. These processing regions 290 can be controlled by the scanning device 240 (or the alternative scanning device 253 or another, not shown, embodiment of a scanning device), with all adjacent processing regions 290 forming the scanning region 247. For clarity, a first processing region 290a, a second processing region 290b, and a third processing region 290c are shown in Fig. 2.

[0157] A temperature T prevails in each work area 290, with thermal radiation emitted from the processing area depending on the temperature T. A portion of this thermal radiation, also referred to as measuring light 110, travels along a detection beam path 291 through the scanning device 240 to a wavelength-selective optical element 293. This wavelength-selective optical element 293 is, for example, a dichroic beam splitter.

[0158] The laser light 221 has a wavelength li as or a wavelength range ALi as , which differs from a wavelength Xmess or a wavelength range AXmess of the measuring light 110. The scanning mirrors 241 reflect both AÄi as , as well as ALmess-

[0159] The wavelength-selective optical element 293, on the other hand, transmits the wavelength li as or the wavelength range AÄi asof the laser light 221 preferably completely (in addition, the wavelength-selective optical element 293 can have an anti-reflection coating in order to keep reflection losses as low as possible) and preferably completely reflects the wavelength Xmess or the wavelength range ALmess of the measuring light 110.

[0160] The detection beam path 291 is thus spatially separated from the processing beam path 223 at the wavelength-selective optical element 293, wherein the detection beam path 291 is shown with a dotted line and coincides with the processing beam path 223 from the sample 280 to the wavelength-selective optical element 293.

[0161] The schematic representation of the figures simplifies the processing beam path 223 and the detection beam path 291 into a single line. Since the laser light 221 has a very low divergence, but the thermal emission of NIR or IR radiation from the sample 280 occurs into the half-space, the detection light 110 propagates in a divergent light cone, the size of which depends, for example, on the equipment of the scanning device 240. This light cone is schematically illustrated in Fig. 2 and in an alternative wavelength-selective element 293a.

[0162] The alternative wavelength-selective element 293a utilizes the different geometry of laser light 221 and measurement light 110 and separates them using a curved mirror 293b with an opening 293c. The laser light 221 can pass through this opening 293c to the sample 280, whereas the measurement light 110 is focused by the curved mirror 293b onto the point sensor 107a. The wavelength-selective element 293 shown here and the alternative wavelength-selective element 293a are purely exemplary possibilities for separating the laser light 221 from the measurement light 110.

[0163] The (alternative) wavelength-selective element 293 (293a) is arranged behind the scanning device 240, as viewed from the sample 280. This has the advantage that the scanning device 240 moves the processing beam path 223 together with the detection beam path 291 within the scanning area 247 of the sample 280. Regardless of which processing area 290 is controlled by the scanning device 240, the measuring light 110 is always guided to the temperature measuring arrangement 100 from exactly the same processing area 290 in which the processing beam path 223 also ends.

[0164] Fig. 3 shows a further embodiment of the UV laser-based system for correcting refractive errors 200 according to the invention, with a temperature measuring arrangement 100 comprising an optical beam offset compensation element 310. This makes it possible to compensate for a beam offset A of the laser light 221 introduced by the wavelength-selective optical element 293. This is achieved by a corresponding orientation of the optical beam offset compensation element 310, whereby the laser light 221 can be guided back to an original propagation path 225 of the laser light 221.

[0165] The optical beam offset compensation element 310 has a wave-independent refractive index n(L), so that the wavelength-selective optical element 293 and the optical beam offset compensation element 310 can be arranged as shown to superimpose the processing beam path 223 with the detection beam path 291.

[0166] For example, a first beam offset A1 can be selected for the measuring light 110 and a second beam offset A2 for the laser light 221. Due to the wavelength-dependent refraction of the optical beam offset compensation element 310, both beam paths are combined at an exit point 311 and run collinearly with each other.

[0167] With small thicknesses of the beam-deflecting wavelength-selective optical element 293, the beam offset A of the laser light 221 can be negligible and the UV laser-based system for correcting ametropia 200 can be operated without the optical beam offset compensation element 310.

[0168] Fig. 4 schematically shows a further embodiment of the UV laser-based system for correcting vision defects 200 according to the invention with a further beam-deflecting wavelength-selective optical element 410, which is designed to analyze light 411 of a wavelength L generated in the sample 280.an spectrally separated from the measuring light 110.

[0169] The analysis light 411 can, for example, be fluorescent light, wherein fluorescence of the material 481 in a material 481 of the sample 280 is excited by excitation light (not shown). The excitation light (not shown) can be radiated into the processing area 290 via the processing beam path 223 or laterally at an angle to the processing beam path 223. In the first case, a further optical wavelength-selective element (not shown) that couples in the analysis light is arranged in the system 200, preferably, but not restrictively, in the processing beam path 223.

[0170] Preferably, the wavelength ranges of the laser light Aü differ as , the measuring light AXm eS s and a wavelength range of the analysis light AA, anfrom each other. The material 481 of the processing area 290 of the sample 280 emits the analysis light 411 in the direction of the scanning device 240. The analysis light 411 propagates up to the wavelength-selective optical element 293 collinearly with the laser light 221 and collinearly with the measuring light 110 along the processing beam path 223 and also the detection beam path 291 and is separated from the laser light 221 together with the measuring light 110. The further beam-deflecting wavelength-selective optical element 410 separates the measuring light 110, which propagates further to the temperature measuring arrangement 100, from the analysis light 411.

[0171] An analysis device 413 is provided for detecting the analysis light 411. This can be configured to determine and provide material data 415, wherein the material data 415 represents the material 481 (and its properties) in the processing area 290. The material data 415 are schematically illustrated in Fig. 4.

[0172] The analysis device 413 can thus receive the analysis light 411, evaluate it and provide the material data 415 based on the analysis light 411.

[0173] For clarity, the measurement light 110 is drawn with a dotted line, the laser light 221 with a dot-dashed line, and the analysis light 411 with a dot-dashed line. Furthermore, for clarity, the beam paths are drawn side by side and not superimposed.

[0174] Figs. 5 to 7 schematically show flow charts to explain the method for providing control data 510. The control data 510 is provided during a planning phase. In some embodiments, the control data 510 can be provided during the measurement of a test specimen (not shown), preferably one whose temperature and / or temperature distribution is adjustable. If a test specimen is used, the methods can be understood as test methods that allow the correct functioning of the method and / or device to be verified.

[0175] Finally, the described methods for providing control data can also be part of a process for providing and adapting control data. This is not discussed in the figures.

[0176] Fig. 5 shows three basic process steps S100, S200, and S300, which can be supplemented by additional optional process steps. The optional process steps are marked with an apostrophe (') and, for clarity, are summarized in subroutines UP. The subroutines are shown schematically in Figs. 6 and 7.

[0177] In step S100, measurement light 110 emitted from a processing area of ​​a sample is detected by a point-shaped temperature sensor 107a (also known as a point sensor). In this step, for example, an electrical signal is generated.

[0178] In the subsequent method step S200, the point sensor 107a generates a temperature signal 120, which represents the temperature T of the processing area 290. This temperature signal 120 is then preferably provided.

[0179] Finally, in process step S300, control data 510 is created. This control data 510 is created in the process as a function of the temperature signal 120.

[0180] In a further embodiment of the method, this can comprise only method steps S200' and S300'. In method step S200', either a temperature signal 120 is generated from a previously measured, stored, and retrieved temperature T of the processing area 290, or a previously stored temperature signal 120 is accessed directly. This temperature signal 120 is further provided. Finally, in method step S300', the control data 510 is created. This control data 510 is created in the method as a function of the temperature signal 120, whereby, unlike in method step S300, the temperature signal does not require a temperature measurement. Method steps S200' and S300' can thus be executed on any computer or a similar computing unit such as an FPGA.

[0181] A further advantageous embodiment of the method comprises method steps S90', S291', and TU and is described schematically in Figs. 5 and 6. In method step S90', control signals 610 are sent that are suitable for controlling a scanning device 240. The control signals 610 represent a sequential approach to a predetermined plurality of spatially separated processing areas 290 by means of the scanning device 240.

[0182] In process step S291', matrix data 620 are included in the control data 510.

[0183] In method step TU, it is merely checked whether all processing areas 290 of the previously defined plurality of spatially separated processing areas 290 have been approached. If this is not the case, method step S90' is carried out again and another processing area 290 is approached. If TU is answered in the affirmative, method step S300 is subsequently carried out and the control data 510 is created. In method step S291', the control data 510 can thus be supplemented sequentially. In other embodiments of the method, the determined temperature values ​​120 of the plurality of processing areas 290 can be added to the control data 510 together in a further method step, i.e., in a block. Between method steps S90' and S291', method steps S100 and S200 are also carried out. This means that a temperature value 120 is determined and provided for each processing area 290.

[0184] The matrix data 620 represent at least one sorting of the plurality of processing areas 290 according to the temperature T of the respective processing areas 290

[0185] Optionally, the method may also include method steps S210' and S220'. In method step S210', previously stored material data 520 is read out and / or material data 520 entered by a user is read in and / or material data 520 is determined. Thus, in the first two options, method step S210' can be fully executed on any computer or any processing unit.

[0186] In the subsequent method step S220', either the material data 520 or parameter change data 530 calculated from the material data 520, or both, are included in the control data 510, wherein the material data 520 and / or the parameter change data 530 represent at least the information about a material-dependent processing parameter 540 and / or about at least one parameter change 550 necessary to achieve a constant processing parameter 540. The previously described embodiments of the method can optionally be transferred to a femtosecond laser-based system.

[0187] Optionally, the method according to the invention can be supplemented by the subroutine UP2. This comprises the method steps S311 to S315.

[0188] In method step S311, previously stored sample volume data 710 are read out and / or sample volume data 710 provided by a user are read in. The sample volume data 710 can represent a volume to be ablated or removed in a vision correction procedure, for example, from the cornea of ​​a human eye. The sample volume data 710 thus preferably represent a three-dimensional volume.

[0189] In method step S312', previously stored ablation data 720 are read out and / or ablation data 720 provided by a user are read in. The ablation data 720 can, for example, represent an ablation rate 721. The ablation rate 721 can, for example, be specified in the unit microliters or nanometers per laser pulse.

[0190] In method step S313', a total number N of processing steps is calculated based on the sample volume data and the removal data. In a simple embodiment, for example, the thickness of the sample volume represented by the sample volume data is divided by the removal rate, and the total number N of processing steps required to remove the entire thickness is obtained. In method step T2', a query is made as to whether the total number N of processing steps is greater than a predetermined number Nnorm of processing steps within the standard range.

[0191] Since the control data 510 is suitable for controlling a UV laser-based system for correcting refractive errors, it is necessary to avoid situations that could damage the tissue being treated, even during or with the control data 510. Particularly during refractive error correction and mechanical ablation of areas of the cornea using a laser, the limit values ​​of the corneal material must be observed. All conditions in which this is met are within the normal range.

[0192] A critical factor is the temperature of the tissue, which should not reach the coagulation temperature. The coagulation temperature is between approximately 50°C and 60°C. However, the risk of permanent tissue damage increases if a temperature > 40°C is reached over a longer period. If a specific temperature is specified for the coagulation temperature, this must be considered or specified in connection with the exposure time. To ensure that no damage to the tissue from previous pulses occurs after ablation, a number Nnorm of processing steps within the standard range is specified or determined as a precaution. These processing steps within the standard range thus represent the Nnorm final processing steps until the desired result is achieved.However, processing steps prior to these final steps may exceed threshold values, even if this results in damage to the treated or directly surrounding tissue. The damaged tissue is subsequently removed, i.e., in the subsequent processing steps. The Nnorm processing steps within the normal range then ensure that previously damaged tissue is subsequently removed.

[0193] If the query in process step T2' is answered in the negative, limit values ​​must not be exceeded and all processing steps to be carried out according to the control data 510 are carried out within the normal range.

[0194] However, if it is determined that more processing steps are required to completely process the sample than the necessary processing steps within the standard range, a difference between the total number N of processing steps and a predetermined number Nnorm of processing steps within the standard range is determined in method step S314'. As already mentioned above, within the standard range according to the processing plan, a predicted parameter, in particular a predicted temperature of the sample within the processing range, is always smaller than a maximum permissible parameter, such as a maximum permissible temperature of the sample.

[0195] In a further method step S315', sequence data 730 are included in the control data 510, wherein the sequence data 730 represents a temporal sequence of (N-Nnom) outside the normal range and Nnorm within the normal range of processing steps to be performed. If the control data 510 is executed by a control unit, the N nO rm processing steps within the standard range take place directly after the (N-Nnorm) processing steps outside the standard range, or after a delay during which the sample cools down by diffusion of heat within it.

[0196] In a further embodiment of the method, the following method steps S230' and S240' (not shown in the figures) can be carried out, which can be carried out after method step S200.

[0197] In method step S230', the temperature signal is compared with a threshold value representing a maximum permissible threshold temperature. In the subsequent method step S240', threshold value data are included in the control data 510, wherein the threshold value data represent at least the information as to whether the temperature signal 120 exceeds the threshold value. These method steps are particularly advantageous during a laser vision correction, since the invention makes it possible to measure the temperature T of the corresponding processing area 290 between two pulses of laser light and, should the measurement result in the threshold value being exceeded, to at least delay the subsequent processing step by means of a laser pulse in order to enable cooling of the processing area 290.This ensures that processing is always carried out within the normal range and that this can be monitored from pulse to pulse.

[0198] According to the invention, the control data 510 created by the method can comprise at least one treatment sequence and / or at least one treatment instruction.Possible treatment sequences include varying the parameters of the laser light depending on whether the threshold value of the temperature T is exceeded in order to reduce the heat input into the sample 280; and / or varying the parameters of the laser light 221 depending on the material data 520 and / or depending on the parameter change data 530; and / or determining the processing area 290 of the plurality of spatially separated processing areas 290 with the lowest temperature T represented by the temperature signal 120 and declaring this processing area 290 as the starting processing area; and / or determining an order of the processing areas 290, wherein the individual processing areas 290 are sorted according to their determined temperature T, and / or performing (N-Nnorm) processing steps outside the standard range and subsequently performing Nnorm processing steps within the standard range.

[0199] The control data 510 can be fed into or provided to a control device 260, so that the control device 260 can control the UV laser-based vision correction system 100 according to the control data 510. It is also conceivable for a control device 260 provided in the vision correction system 100 to independently generate the control data 510 or independently correct the control data 510 and thus adapt it to a treatment process. Thus, unforeseen variations in the treatment process, such as an unexpectedly high temperature in a treatment area 290, can be detected and reacted to accordingly to protect the patient.

[0200] The representation of a non-volatile storage medium that can be read by a computer, as well as the representation of a computer, will be omitted here, since these elements are sufficiently well known.

[0201] List of reference symbols

[0202] 100 temperature measuring arrangement

[0203] 101 housings

[0204] 101a Signal line

[0205] 103 Entrance opening

[0206] 103a recess

[0207] 105 optical imaging system

[0208] 105a lens

[0209] 107 Temperature sensor

[0210] 107a Point sensor

[0211] 107b electrical circuit board

[0212] 107c pixels

[0213] 109 Interior

[0214] 110 measuring light

[0215] 110a infrared or near-infrared light

[0216] 120 temperature signal

[0217] 200 UV laser based system for vision correction

[0218] 220 laser light source

[0219] 221 laser light

[0220] 223 Processing beam path

[0221] 240 scanning device

[0222] 241 scanning mirrors

[0223] 243 Rotational movement

[0224] 245 axis of rotation

[0225] 247 scan area

[0226] 249 first deflection direction

[0227] 251 second deflection direction

[0228] 253 alternative scanning device

[0229] 255 deflection prism

[0230] 257 linear movement

[0231] 260 Control device

[0232] 280 samples

[0233] 281 sample area

[0234] 283 Eye

[0235] 290 processing area

[0236] 290a first processing area 290b second processing area

[0237] 290c third processing area

[0238] 293 wavelength-selective optical element

[0239] 310 optical beam offset compensation element

[0240] 311 Exit Point

[0241] 410 additional wavelength-selective optical element

[0242] 411 Analysis light

[0243] 413 Analysis device

[0244] 415 Material data

[0245] 481 materials

[0246] 510 tax data

[0247] 520 material data

[0248] 530 Parameter change data

[0249] 540 processing parameters

[0250] 550 Parameter change

[0251] 610 Control signal

[0252] 620 matrix data

[0253] 710 sample volume data

[0254] 720 erosion data

[0255] 721 Ablation rate

[0256] 730 expiration dates

[0257] T Temperature

[0258] Xus wavelength of laser light

[0259] Xmess Wavelength of the measuring light Wavelength of the analysis light Wavelength range of the laser light Wavelength range of the measuring light Wavelength range of the analysis light n(l) Wave-independent refractive index Beam offset First beam offset Second beam offset

Claims

Patent claims 1. Temperature measuring arrangement (100) for a UV laser-based system for correcting ametropia (200) or for a femtosecond laser-based system for corneal crosslinking (CXL) or for laser-induced changing of the refractive index (LIRIC), which is designed to generate and emit laser light (221) and to process a processing area (290) of a sample (280) to be processed with the laser light (221), wherein the temperature measuring arrangement (100) comprises at least one temperature sensor (107) for detecting a temperature signal (120) representing the temperature (T) of the processing area (290), and wherein the temperature sensor (107) has at least one point sensor (107a) and an optical imaging system (105) imaging the measuring light (110) onto the at least one point sensor (107a).

2. Temperature measuring arrangement (100) according to claim 1, further comprising at least one beam-deflecting and wavelength-selective optical element (293), wherein the wavelength-selective optical element (293) is designed to combine a detection beam path (291) of measuring light (110) emitted from the processing area (290) with a processing beam path (223) of the laser light (221).

3. Temperature measuring arrangement (100) according to claim 2, further comprising an optical beam offset compensation element (310) which is designed to compensate for a beam offset (A) of the laser light (221) introduced by the wavelength-selective optical element (293).

4. A UV laser-based system for correcting ametropia (200) or a femtosecond laser-based system for corneal crosslinking or for laser-induced changes in the refractive index, comprising a temperature measuring arrangement (100) according to any one of claims 1 to 3; a laser light source (220) generating the laser light (221) or a femtosecond laser light source generating the laser light (221); a scanning device (240) moving the laser light (221) in a sample region (281); and at least one control device (260), wherein the control device (260) is configured to control the laser light source (220) and / or the scanning device (240) as a function of the temperature signal (120) of the temperature measuring arrangement (100).

5. UV laser-based system for correcting ametropia (200) or femtosecond laser-based system for corneal crosslinking or for laser-induced changing of the refractive index according to claim 4, wherein the beam-deflecting, wavelength-selective optical element (293) is arranged between the laser light source (220) and the scanning device (240) in a processing beam path (223) of the laser light (221) or can be introduced into the processing beam path (223) of the laser light (221).

6. UV laser-based system for correcting ametropia (200) or femtosecond laser-based system for corneal crosslinking or for laser-induced changing of the refractive index according to claim 4 or 5, wherein the scanning device (240) comprises at least one scanning mirror (241) which reflects at least one wavelength range (Alias) of the laser light (221) and one wavelength range (ALmess) of the measuring light (110).

7. UV laser-based system for correcting ametropia (200) or femtosecond laser-based system for corneal crosslinking or for laser-induced changing of the refractive index according to one of claims 4 to 6, further comprising a further beam-deflecting wavelength-selective optical element (410) which is designed to spectrally separate analysis light (411) generated in the sample (280) from the laser light (221) and from the measuring light (110), wherein the wavelength ranges (Ali as , AXmess) of the laser light (221) and the measuring light (110) and a wavelength range of the analysis light (AA, an ) from one another and wherein the system (200) further comprises an analysis device (413) for determining material data (415) representing a material (481) of the processing area (290), wherein the analysis device (413) is designed to receive the analysis light (411), evaluate it and provide the material data (415).

8. UV laser-based system for correcting ametropia (200) or femtosecond laser-based system for corneal crosslinking or for laser-induced changing of the refractive index according to one of claims 4 to 7, wherein the control device (260) is designed as a function of the temperature signal (120) to select at least one processing parameter (540) from the list of parameters (540), preferably stored in advance in the system for correcting ametropia (200), comprising: Coordinates of a selected processing area (290) of the sample (280); at least one beam parameter of the laser light source (220); and at least one environmental parameter.

9. Method for providing control data (510) for thermal optimization of a treatment by means of a UV laser-based system for correcting ametropia (200) or for the thermal optimization of a treatment using a femtosecond laser-based system for corneal crosslinking or for laser-induced changes in the refractive index, the method comprising the following method steps: b) detecting measuring light (110) emitted from a processing area (290) of a sample (280) with a point-shaped temperature sensor (107a); c) generating and providing a temperature signal (120) representing the temperature (T) of the processing area (290) by the point-shaped temperature sensor (107a); and d) creating control data (510), the control data (510) being created as a function of the temperature signal (120) and providing the control data (510).

10. The method according to claim 9, further comprising the method steps: a) sending control signals (610) to a scanning device (240), wherein the control signals (610) represent a sequential approach to a predetermined plurality of spatially separated processing areas (290) by means of the scanning device (240); and c3) incorporating matrix data (620) into the control data (510), wherein the matrix data (620) represent at least one sorting of the plurality of processing areas (290) according to the temperature (T) of the respective processing areas (290), wherein method step a) is carried out chronologically before method step b) and method step c3) is carried out chronologically after method step c).

11. The method according to claim 9 or 10, further comprising reading out previously stored material data (481) and / or reading in material data (481) entered by a user and / or determining material data (481) and further comprising the method step: c4) recording the material data (481) and / or recording parameter change data (530) calculated from the material data (481) in the control data (510), wherein the material data (481) and / or the parameter change data (530) represent at least the information about a material-dependent processing parameter (540) and / or about at least one parameter change (550) necessary to achieve a constant processing parameter (540), wherein method step c4) is carried out chronologically after method step c).

12. The method according to any one of claims 9 to 11, further comprising el) reading out pre-stored sample volume data (710) and / or reading in sample volume data (710) provided by a user; e2) reading out pre-stored ablation data (720) and / or reading in ablation data (720) provided by a user, wherein the ablation data (720) represents an ablation rate (721); e3) determining a total number N of processing steps based on the sample volume data (710) and the ablation data (720); e4) determining a difference between the total number N of processing steps and a predetermined number Nnorm of processing steps in the normal range, wherein in the normal range according to control data (510) a predicted temperature (T) of the sample (280) in the processing area (290) is always lower than a maximum permissible temperature of the sample;and e5) including expiration data (730) in the control data (510), wherein the expiration data (730) has a temporal expiration of (N-Nnom) outside the normal range and N; nO rm represent processing steps to be carried out within the standard range.

13. The method according to any one of claims 9 to 12, further comprising the method steps c1) comparing the temperature signal (120) with a threshold value representing a maximum permissible threshold temperature; and c2) incorporating threshold value data into the control data (510), wherein the Threshold data represent at least the information as to whether the temperature signal exceeds the threshold value; wherein method steps c1) and c2) are carried out chronologically after method step c).

14. The method according to any one of claims 9 to 13, wherein the control data (510) created by the method comprise at least one treatment sequence and / or at least one treatment instruction from the following list: Varying parameters (540) of the laser light (221) depending on exceeding the threshold value of the temperature (T) in order to reduce the heat input into the sample (280); and / or Varying parameters (540) of the laser light (221) depending on the material data (481) and / or depending on the parameter change data (530); and / or Determining the processing area (290) of the plurality of spatially separated processing areas (290) with the lowest, determined by the temperature signal (120) represented temperature (T) and declaring this processing area (290) as the start processing area; and / or Determining an order of the processing areas (290), wherein the individual processing areas (290) are sorted according to their determined temperature (T), and / or Transit of (NN n orm) processing steps outside the standard range and subsequent execution of Nnorm processing steps within the standard range.

15. A method for providing and adapting control data, in which a first processing step is carried out, during which at least one laser pulse of a laser light source processes a processing area of ​​a sample area according to initial control data; new control data are provided according to a method for providing control data according to one of claims 9 to 14; and Based on the new tax data provided, the initial tax data will be adjusted.

16. Control device (260) for a UV laser-based system for correcting ametropia (200) or for a femtosecond laser-based system for corneal crosslinking or for laser-induced changes in the refractive index with a temperature measuring arrangement (100) according to one of claims 1 to 3, wherein the control device (260) is designed to control a laser light source (220) of the system (200) and / or a scanning device (240) of the system (200) depending on the temperature signal (120) of the temperature measuring arrangement (100), and wherein the control device (260) is designed to control a UV laser-based system for correcting ametropia (200) or a femtosecond laser-based system for corneal crosslinking or for laser-induced changes in the refractive index according to control data (510) which are generated by a method according to one of claims 9 to 14 were preserved.

17. A method for correcting vision defects or for corneal crosslinking or for laser-induced changes in the refractive index of a human eye (283), comprising the following method steps: e6) detecting measuring light (110) emitted from a processing area (290) of the human eye (283) with a point-shaped temperature sensor (107a); e7) generating and providing a temperature signal (120) representing the temperature (T) of the processing area (290) by the point-shaped temperature sensor (107a); e8) Creating control data (510) representing process steps of the refractive error correction or process steps of the corneal crosslinking or the laser-induced change of the refractive index, wherein the control data (510) are created as a function of the temperature signal (120); and e9) controlling a UV laser-based system for refractive error correction (200) and Carrying out the refractive error correction on the human eye (283) according to the control data (510) or controlling a femtosecond laser-based system for corneal crosslinking or for laser-induced changing of the refractive index and carrying out the crosslinking or the laser-induced changing of the refractive index according to the control data.

18. A computer program product which, when executed on a UV laser-based system for correcting ametropia (200) or on a femtosecond laser-based system for corneal crosslinking or for laser-induced changing of the refractive index according to one of claims 4 to 8, is designed to carry out a method according to one of claims 9 to 14.

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