TREATMENT APPARATUS FOR AN EYE TREATMENT, METHOD, COMPUTER PROGRAM AND COMPUTER-READABLE MEDIUM

Abstract

The invention relates to a treatment apparatus for an eye treatment, at least comprising: at least one laser beam source configured for emission of laser pulses, at least one beam exit device, which is configured to pass the respective laser pulses with a predetermined laser pulse cross-sectional profile to respective impingement positions in a treatment surface of a preset treatment volume of an eye to be treated, a control device, which is configured to ascertain coordinates of the respective impingement positions in the treatment surface according to at least two predetermined coordinate ascertaining methods for the preset treatment volume and the predetermined laser pulse cross-sectional profile. The control device is configured to ascertain respective expectable treatment roughnesses of the treatment volume depending on coordinate ascertaining method, according to a predetermined roughness ascertaining method for the at least two coordinate ascertaining methods, to determine the predetermined coordinate ascertaining method of a smallest expectable treatment roughness depending on coordinate ascertaining method as the coordinate ascertaining method to be adjusted, and to adjust the coordinates of the respective impingement positions according to the coordinate ascertaining method to be adjusted, in the at least one beam exit device.

Claims

1. A treatment apparatus for an eye treatment, at least comprising: at least one laser beam source, configured for emission of laser pulses, at least one beam exit device, which is configured to guide the respective laser pulses with a predetermined laser pulse cross-sectional profile to respective impingement positions in a treatment surface of a preset treatment volume of an eye to be treated, a control device, which is configured to ascertain coordinates of the respective impingement positions in the treatment surface according to at least two predetermined coordinate ascertaining methods for the preset treatment volume and the predetermined laser pulse cross-sectional profile, to ascertain respective treatment roughnesses of the treatment volume depending on coordinate ascertaining method expectable for the preset treatment volume, according to a predetermined roughness ascertaining method for the at least two predetermined coordinate ascertaining methods, to determine the predetermined coordinate ascertaining method of a smallest expectable treatment roughness depending on coordinate ascertaining method as the coordinate ascertaining method to be adjusted, and to adjust the coordinates of the respective impingement positions according to the coordinate ascertaining method to be adjusted, in the at least one beam exit device.

2. The treatment apparatus according to claim 1, wherein the control device is configured, to ascertain respective treatment roughnesses of the treatment volume expectable for the preset treatment volume depending on profile, according to a predetermined profile ascertaining method for at least two potential laser pulse cross-sectional profiles of the laser pulses before the eye treatment, to determine the potential laser pulse cross-sectional profile of a smallest expectable treatment roughness depending on profile as the predetermined laser pulse cross-sectional profile, and to adjust the predetermined laser pulse cross-sectional profile in the at least one beam exit device.

3. The treatment apparatus according to claim 1, wherein the control device is configured to ascertain respective coordinate sets including varied coordinates of the respective impingement positions from the coordinates according to at least two predetermined jitter methods before the eye treatment, wherein the varied coordinates of the coordinate sets are shifted by respective jitter shifts with respect to the coordinates in the treatment surface, to ascertain respective expectable treatment roughnesses of the treatment volume depending on jitter according to a predetermined jitter roughness ascertaining method for the respective coordinate sets, and to replace the coordinates with the varied coordinates of the coordinate set of a smallest expectable treatment roughness depending on jitter.

4. The treatment apparatus according to claim 1, wherein the at least two predetermined coordinate ascertaining methods include at least one preset dithering method.

5. The treatment apparatus according to claim 1, wherein the at least two predetermined coordinate ascertaining methods include at least one preset dithering method, and wherein the at least two predetermined coordinate ascertaining methods include at least one of the following predetermined dithering methods: Floyd-Steinberg, thresholding, random dithering, ordered dithering, Bayer matrix, minimized average error, Stucki dithering, Burkes dithering, Sierra dithering, two-row Sierra, filter lite, Atkinson dithering or gradient-based error-diffusion dithering.

6. The treatment apparatus according to claim 1, wherein the control device is configured, to ascertain respective treatment roughnesses of the treatment volume expectable for the preset treatment volume depending on profile, according to a predetermined profile ascertaining method for at least two potential laser pulse cross-sectional profiles of the laser pulses before the eye treatment, to determine the potential laser pulse cross-sectional profile of a smallest expectable treatment roughness depending on profile as the predetermined laser pulse cross-sectional profile, and to adjust the predetermined laser pulse cross-sectional profile in the at least one beam exit device, wherein the at least two potential laser pulse cross-sectional profiles include at least one Gaussian cross-sectional profile.

7. The treatment apparatus according to claim 1, wherein the control device is configured, to ascertain respective treatment roughnesses of the treatment volume expectable for the preset treatment volume depending on profile, according to a predetermined profile ascertaining method for at least two potential laser pulse cross-sectional profiles of the laser pulses before the eye treatment, to determine the potential laser pulse cross-sectional profile of a smallest expectable treatment roughness depending on profile as the predetermined laser pulse cross-sectional profile, and to adjust the predetermined laser pulse cross-sectional profile in the at least one beam exit device, wherein the at least two potential laser pulse cross-sectional profiles include at least one pinhole cross-sectional profile.

8. The treatment apparatus according to claim 1, wherein the control device is configured, to ascertain respective treatment roughnesses of the treatment volume expectable for the preset treatment volume depending on profile, according to a predetermined profile ascertaining method for at least two potential laser pulse cross-sectional profiles of the laser pulses before the eye treatment, to determine the potential laser pulse cross-sectional profile of a smallest expectable treatment roughness depending on profile as the predetermined laser pulse cross-sectional profile, and to adjust the predetermined laser pulse cross-sectional profile in the at least one beam exit device, wherein the at least two potential laser pulse cross-sectional profiles have different half widths at full maximum.

9. The treatment apparatus according to claim 1, wherein the control device is configured, to ascertain respective treatment roughnesses of the treatment volume expectable for the preset treatment volume depending on profile, according to a predetermined profile ascertaining method for at least two potential laser pulse cross-sectional profiles of the laser pulses before the eye treatment, to determine the potential laser pulse cross-sectional profile of a smallest expectable treatment roughness depending on profile as the predetermined laser pulse cross-sectional profile, and to adjust the predetermined laser pulse cross-sectional profile in the at least one beam exit device, wherein the at least two potential laser pulse cross-sectional profiles have various maximum radiant exposures.

10. The treatment apparatus according to claim 1, wherein the control device is configured to ascertain respective coordinate sets including varied coordinates of the respective impingement positions from the coordinates according to at least two predetermined jitter methods before the eye treatment, wherein the varied coordinates of the coordinate sets are shifted by respective jitter shifts with respect to the coordinates in the treatment surface, to ascertain respective expectable treatment roughnesses of the treatment volume depending on jitter according to a predetermined jitter roughness ascertaining method for the respective coordinate sets, and to replace the coordinates with the varied coordinates of the coordinate set of a smallest expectable treatment roughness depending on jitter, wherein the at least two predetermined jitter methods include at least one random jitter method.

11. The treatment apparatus according to claim 1, wherein the control device is configured to ascertain respective coordinate sets including varied coordinates of the respective impingement positions from the coordinates according to at least two predetermined jitter methods before the eye treatment, wherein the varied coordinates of the coordinate sets are shifted by respective jitter shifts with respect to the coordinates in the treatment surface, to ascertain respective expectable treatment roughnesses of the treatment volume depending on jitter according to a predetermined jitter roughness ascertaining method for the respective coordinate sets, and to replace the coordinates with the varied coordinates of the coordinate set of a smallest expectable treatment roughness depending on jitter, wherein the at least two predetermined jitter methods include at least one deterministic jitter method.

12. A method for controlling a treatment apparatus by a control device, which is configured for controlling the treatment apparatus, comprising at least the steps: ascertaining coordinates of respective impingement positions in a treatment surface for a preset treatment volume and a predetermined laser pulse cross-sectional profile according to at least two predetermined coordinate ascertaining methods, ascertaining respective treatment roughnesses of the treatment volume depending on coordinate ascertaining method expectable for the preset treatment volume, according to a predetermined roughness ascertaining method for the at least two predetermined coordinate ascertaining methods, determining the predetermined coordinate ascertaining method of a smallest expectable treatment roughness depending on coordinate ascertaining method as a coordinate ascertaining method to be adjusted, and adjusting the coordinates of the respective impingement positions of the coordinate ascertaining method to be adjusted, in the beam exit device.

13. The method for controlling the treatment apparatus according to claim 12, comprising the further steps: ascertaining the respective treatment roughnesses of the treatment volume depending on profile expectable for the preset treatment volume for the at least two potential laser pulse cross-sectional profiles of the laser pulses according to the predetermined profile ascertaining method, determining the laser pulse cross-sectional profile of the smallest expectable treatment roughness depending on profile as the predetermined laser pulse cross-sectional profile, and adjusting the predetermined laser pulse cross-sectional profile in the at least one beam exit device, and/or the further steps: ascertaining respective coordinate sets including varied coordinates from the coordinates according to the at least two predetermined jitter methods, wherein the varied coordinates of the coordinate sets are shifted by respective jitter shifts in the treatment surface with respect to the coordinates in the treatment surface, ascertaining the respective treatment roughnesses of the treatment volume depending on jitter expectable for the preset treatment volume for the respective coordinate sets according to the predetermined jitter roughness ascertaining method, and replacing the coordinates with the varied coordinates of the coordinate set of the smallest expectable treatment roughness depending on jitter.

14. A computer program including commands, which cause a control device to execute the method steps according to claim 12.

15. A non-transitory computer-readable medium, on which the computer program according to claim 14 is stored.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Further features of the invention are apparent from the claims, the figures and the description of figures. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of figures and/or shown in the figures alone are usable not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention. Thus, implementations are also to be considered as encompassed and disclosed by the invention, which are not explicitly shown in the figures and explained, but arise from and can be generated by separated feature combinations from the explained implementations. Implementations and feature combinations are also to be considered as disclosed, which thus do not comprise all of the features of an originally formulated independent claim. Moreover, implementations and feature combinations are to be considered as disclosed, in particular by the implementations set out above, which extend beyond or deviate from the feature combinations set out in the relations of the claims.

[0039] FIG. 1 is a schematic representation of a treatment apparatus for an eye treatment.

[0040] FIG. 2 is a schematic representation of two patterns.

[0041] FIG. 3 is a schematic representation of a shift of the coordinates by jitter shifts.

[0042] FIG. 4 is a schematic representation of possible laser pulse cross-sectional profiles.

[0043] FIG. 5 is a schematic representation of a procedure of a method for controlling the treatment apparatus.

DETAILED DESCRIPTION

[0044] FIG. 1 shows a schematic representation of a treatment apparatus for an eye treatment. The treatment apparatus 1 comprises at least one laser beam source 2, which may be configured to emit laser pulses 3. In addition, the treatment apparatus 1 may comprise at least one beam exit device 4, which may be configured to guide the respective laser pulses 3 with a predetermined laser pulse cross-sectional profile 5 to respective impingement positions 6 onto a treatment surface 7 of a preset treatment volume 8 of an eye 9 to be treated. The treatment apparatus 1 may comprise a control device 10, which may be configured to control the beam exit device 4 and the laser beam source 2 for ablating the treatment volume 8. It may be provided that the ablation of the treatment volume 8 is preferably effected such that lateral surfaces 11 of the treatment volume 8 and a basic surface 12 of the treatment volume 8 have a minimum surface roughness. The surface roughness of the lateral surfaces 11 of the treatment volume 8 and the surface roughness of the basic surface 12 of the treatment volume 8 may be combined as treatment roughness of the treatment volume 8. The treatment roughness of the treatment volume 8 may depend on multiple factors. In order to be able to overall minimize the treatment roughness of the treatment volume 8, it may therefore be required to individually optimize the individual parameters, which influence the surface roughness.

[0045] The surface roughness may depend on the laser pulse cross-sectional profile 5 of the laser pulses 3. By the choice of the predetermined laser pulse cross-sectional profile 5, it is thus possible to reduce the treatment roughness. The control device 10 may be configured to ascertain respective treatment roughnesses of the treatment volume 8 depending on profile expectable for the preset treatment volume 8, according to a predetermined profile ascertaining method for at least two potential laser pulse cross-sectional profiles 5 of the laser pulses 3 before the eye treatment. In other words, at least two laser pulse cross-sectional profiles 5 may be stored in the control device 10, which may have the laser pulses 3 generated by the treatment apparatus 1. The laser pulse cross-sectional profiles 5 may for example include a Gaussian profile. The laser pulse cross-sectional profiles 5 may describe an intensity distribution of the respective laser pulses 3 across a radius of the laser pulses 3. Depending on the laser pulse cross-sectional profiles 5 of the respective laser pulses 3, respective treatment roughnesses of the treatment volume 8 may arise. The control device 10 may be configured to ascertain respective treatment roughnesses of the treatment volume 8 depending on profile expectable for the preset treatment volume 8, according to the predetermined profile ascertaining method for the at least two potential laser pulse cross-sectional profiles 5 of the laser pulses 3. In other words, the control device 10 may be configured to ascertain the respective treatment roughnesses of the treatment volume 8 depending on profile according to the predetermined profile ascertaining method for the at least two potential laser pulse cross-sectional profiles 5, which would arise upon choice of the respective laser pulse cross-sectional profile 5. The control device 10 may be configured to ascertain the laser pulse cross-sectional profile 5 of the smallest expectable treatment roughness depending on profile as the predetermined laser pulse cross-sectional profile 5, and to adjust the predetermined laser pulse cross-sectional profile 5 in the at least one beam exit device 4 during the treatment method.

[0046] Possible ones of the laser pulse cross-sectional profiles 5 are shown in FIG. 4. They may differ from each other in their maximum radiant exposures 14, their courses and/or their full widths at half maximum 18. It may be provided that the laser pulse cross-sectional profiles 5 may be laterally restricted by a shutter. Thereby, edge areas, which are outside of a selected distance to the center, may be removed. Accordingly, the laser pulse cross-sectional profiles 5 may be restricted to a pinhole width 19.

[0047] The control device 10 may be configured to ascertain the coordinates 13 of the respective impingement positions 6 of the laser pulses 3 in the treatment surface 7 according to at least two predetermined coordinate ascertaining methods for the preset treatment volume 8 and the predetermined laser pulse cross-sectional profile 5. The at least two coordinate ascertaining methods may include matrices, which may allow ascertaining the coordinates 13 of the respective impingement positions 6 in the treatment surface 7. The coordinate ascertaining methods may for example include the following methods: Floyd-Steinberg, thresholding, random dithering, ordered dithering, Bayer matrix, minimized average error, Stucki dithering, Burkes dithering, Sierra dithering, two-row Sierra, filter lite, Atkinson dithering or gradient-based error-diffusion dithering.

[0048] By the respective coordinate ascertaining methods, different coordinate sets of the respective coordinates 13 of the impingement positions 6 in the treatment surface 7 may be ascertained. The treatment roughnesses depending on coordinate ascertaining method, which result therefrom for the treatment volume 8, may differ from each other. Thus, it may be required to minimize the treatment roughness influenced by the choice of the coordinate ascertaining method.

[0049] It may be provided that the control device 10 is configured to ascertain the treatment roughnesses of the treatment volume 8 depending on coordinate ascertaining method expectable for the at least two coordinate ascertaining methods for the preset treatment volume 8 according to a predetermined dithering roughness ascertaining method before performing the treatment method. In other words, the control device 10 is configured to ascertain, which treatment roughnesses depending on coordinate ascertaining method would arise for the respective coordinate ascertaining methods in performing the treatment. The control device 10 may be configured to compare the treatment roughnesses depending on coordinate ascertaining method of the respective coordinate ascertaining methods to each other and to determine the coordinate ascertaining method of a smallest expectable treatment roughness depending on coordinate ascertaining method as the predetermined coordinate ascertaining method. This means that the coordinates 13 of the respective impingement positions 6 are adjusted according to the predetermined coordinate ascertaining method in the at least one beam exit device 4 by the control device 10 during the treatment method.

[0050] A possibility of influencing the treatment roughness is in an adaptation of the coordinates 13 of the impingement positions 6 to varied coordinates 15 of the impingement positions 6 by means of so-called jitter methods. Jitter methods may generate jitter shifts 16 from the coordinates 13 to the varied coordinates 15, which may be effected in random manner according to so-called random jitter methods or in deterministic manner according to so-called deterministic jitter methods. The control device 10 may be configured to generate respective varied coordinate sets including the varied coordinates 15 of the respective impingement positions 6 from the coordinates 13 according to at least two jitter methods before the eye treatment, wherein the varied coordinates 15 are shifted by respective jitter shifts 16 with respect to the coordinates 13 of the treatment surface 7. The control device 10 may be configured to ascertain respective expectable treatment roughnesses of the treatment volume 8 depending on jitter for the respective coordinate sets according to the predetermined jitter roughness ascertaining method, and to replace the coordinates 13 with the varied coordinates 15 of the coordinate set of a smallest expectable treatment roughness depending on jitter. In other words, the control device 10 may be configured to ascertain the treatment roughnesses depending on jitter for the respective jitter methods, which would arise for the respective jitter methods. The jitter method, which would result in a smallest expectable treatment roughness depending on jitter is used to replace the coordinates 13 with the varied coordinates 15.

[0051] It may be provided that the ablation of the preset treatment volume 8 may be effected in layers, wherein layers 17 of the treatment volume 8 arranged one below the other may differ from each other in their predetermined laser pulse cross-sectional profile 5, the selected coordinate ascertaining method and/or the selected jitter method. Thereby, surface roughnesses in the basic surface 12 of the treatment volume 8 may for example be reduced. Similarly, it is possible to separately consider effects depending on depth in different depths of the treatment volume 8.

[0052] A computer program 23 may include commands, which cause the treatment apparatus 1 to perform a method for the eye treatment, for example controlled by the control device 10. The computer program 23 may be stored on a computer-readable medium, for example a hard disk, an USB stick or a CD.

[0053] FIG. 2 shows a schematic representation of two patterns. The two patterns 20 show respective distributions of cutting depths 21 in μm in the treatment surface 7, which may arise in an ablation of the treatment volume 8. The treatment surface 7 may be situated in an X-Y plane. The patterns 20 may arise due to the positions 13, which are ascertained generated according to respective ones of the dithering methods. The positions 13 may be ascertained by two different ones of the coordinate ascertaining methods for the identical laser pulse cross-sectional profile 5. Depending on the selected coordinate ascertaining method, the surface roughnesses of the lateral surfaces 11 and/or the basic surface 12 of the treatment volume 8 may differ from each other.

[0054] FIG. 3 shows a schematic representation of a shift of coordinates by jitter shifts The respective jitter method may preset, by which jitter shifts 16 the varied coordinates 15 of the impingement points 6 are shifted with respect to the coordinates 13 of the impingement points 6. The jitter method may for example be a random jitter method, which may preset a shift of the coordinates 13 to the varied coordinates 15 by random values. A deterministic jitter method may also be preset, which may for example preset periodic jitter shifts 16 across adjacent impingement points 6.

[0055] FIG. 4 shows possible laser pulse cross-sectional profiles. The radial course 22 of the radiant exposure H (radiant exposure) across the radial cross-section R of the laser cross-sectional profiles is illustrated. The laser pulse cross-sectional profiles 5 may differ from each other in their courses 22, their maximum radiant exposures 14 and/or their full widths at half maximum 18. It may be provided that laser pulse cross-sectional profiles 5 are guided through a shutter to limit them to a pinhole width 19.

[0056] FIG. 5 shows a schematic representation of a procedure of a method for controlling the treatment apparatus.

[0057] In a first step S1, a treatment volume 8 to be ablated, which includes a treatment surface 7 of an eye 9, may be preset to the control device 10. In other words, the control device 10 may receive a treatment volume 8 to be treated by the treatment apparatus 1.

[0058] It may be provided that parameters for performing the treatment method are ascertained by the control device 10 in a second step S2 of the method. The ascertainment may include multiple partial steps, which may be performed in parallel or sequential manner.

[0059] In the second step S2, a coordinate ascertaining method and/or a jitter method and/or a laser pulse cross-sectional profile 5 may be ascertained by the control device 10, which may result in a minimum treatment roughness of the treatment volume 8. The ascertainment of the preset coordinate ascertaining method, the ascertainment of the preset laser pulse cross-sectional profile 5 and/or the ascertainment of the preset jitter method may be effected in parallel or sequential manner.

[0060] In a partial step A1 of the step S2, at least two of the laser pulse cross-sectional profiles 5, which may have the laser pulses 3 output by the treatment apparatus 1, may be retrieved from a storage by the control device 10.

[0061] In a partial step A2 of the step S2, respective treatment roughnesses of the treatment volume 8 depending on profile expectable for the preset treatment volume 8 may be ascertained according to a predetermined profile ascertaining method for the at least two laser pulse cross-sectional profiles 5 of the laser pulses 3 by the control device 10.

[0062] In a partial step A3 of the step S2, that one of the at least two laser pulse cross-sectional profiles 5 may be ascertained as the predetermined laser pulse cross-sectional profile 5 by the control device 10, which has a smallest expectable treatment roughness depending on profile.

[0063] In a partial step B1 of the step S2, the control device 10 may ascertain an ascertainment of the coordinates 13 of the respective impingement positions 6 in the treatment surface 7 for the preset treatment volume 8 and the predetermined laser pulse cross-sectional profile 5 according to the respective coordinate ascertaining methods. In other words, the coordinates 13 of the respective impingement positions 6 are ascertained by the control device 10 according to at least two different coordinate ascertaining methods for the treatment surface 7.

[0064] In a partial step B2 of the step S2, respective treatment roughnesses of the treatment volume 8 depending on coordinate ascertaining method expectable for the preset treatment volume 8 may be ascertained according to a predetermined roughness ascertaining method for the at least two coordinate ascertaining methods. The treatment roughnesses depending on coordinate ascertaining method may for example be ascertained by means of simulations or mathematic methods.

[0065] In a partial step B3 of the step S2, the coordinate ascertaining method may be ascertained, which results in the smallest treatment roughness depending on coordinate ascertaining method. This coordinate ascertaining method may be used as the predetermined coordinate ascertaining method for performing the eye treatment by the control device 10.

[0066] In a partial step C1 of the step S2, it may be provided that the coordinates 13 of the impingement positions 6 are transformed to varied coordinates 15 according to at least two jitter methods by the control device 10, wherein the varied coordinates 15 may be shifted by jitter shifts 16 from the coordinates 13.

[0067] In a partial step C2 of the step S2, respective expectable treatment roughnesses of the treatment volume 8 depending on jitter may be ascertained according to a predetermined jitter roughness ascertaining method for the respective jitter methods by the control device 10.

[0068] In a partial step C3 of the step S2, it may be provided that the coordinates 13 are replaced with the varied coordinates 13 of the jitter method of a smallest expectable treatment roughness depending on jitter.

[0069] By ascertaining the coordinate ascertaining method, the jitter method and the laser pulse cross-sectional profile 5 before the treatment, which each result in a smallest treatment roughness of the treatment volume 8, a minimum treatment roughness of the treatment volume 8 may be achieved by the treatment.

[0070] The method steps may be repeated for different layers 17 of the treatment volume 8. The layers 17 may be partial volumes of the treatment volume 8, which may be arranged one below the other or next to each other with respect to a depth.

[0071] In a method step S3, the treatment method may be performed, wherein the treatment apparatus 1 may be controlled by the control device 10, in order that the treatment apparatus 1 outputs the laser pulses for treating the treatment volume 8.

[0072] By the invention, the advantage arises that the values, which result in a minimum roughness, are ascertained before performing the eye treatment.

LIST OF REFERENCE CHARACTERS

[0073] 1 Treatment apparatus [0074] 2 laser beam source [0075] 3 laser pulses [0076] 4 beam exit device [0077] 5 laser pulse cross-sectional profile [0078] 6 impingement positions [0079] 7 treatment surface [0080] 8 treatment volume [0081] 9 eye [0082] 10 control device [0083] 11 lateral surface [0084] 12 basic surface [0085] 13 coordinates [0086] 14 maximum radiant exposure [0087] 15 varied coordinates [0088] 16 jitter shift [0089] 17 layers [0090] 18 full width at half maximum [0091] 19 pinhole width [0092] 20 pattern [0093] 21 cutting depth [0094] 22 course of a laser pulse cross-sectional profile [0095] 23 computer program [0096] 24 computer-readable medium [0097] S1-S3 method steps [0098] A1-A3 partial method steps [0099] B1-B3 partial method steps [0100] C1-C3 partial method steps