METHODS FOR CONTROLLING A LASER OF A PROCESSING APPARATUS AND PERFORMING A SURGICAL PROCEDURE FOR THE SEPARATION OF A VOLUME BODY, A PROCESSING APPARATUS, A COMPUTER PROGRAM AND A COMPUTER-READABLE MEDIUM

Abstract

The invention relates to a method for controlling a laser (18) for the separation of a volume body (12) with an anterior interface (16) and with a posterior interface (14): determining a depth relief (48) of the volume body (12) to be generated between the anterior interface (16) and the posterior interface (14); determining a reference point (52) of an axis of symmetry of the determined depth relief (48) or of a respective interface (14, 16) by means of the control device (20); controlling the laser (18) starting from the determined reference point (52) in tracks circle-like at least in certain areas such that it emits pulsed laser pulses in a shot sequence in a predefined pattern into the material, wherein the interfaces are generated by means of an interaction of the individual laser pulses with the cornea (44) by the generation of a plurality of cavitation bubbles (40) along the circle-like tracks. Further, the invention relates to a processing apparatus, to a computer program as well as to a computer-readable medium.

Claims

1. A method for controlling a laser of a processing apparatus for separation from a material of a volume body with an anterior interface and with a posterior interface, wherein the method is executed by a control device of the processing apparatus and comprises: determining a depth relief of the volume body to be generated between the anterior interface and the posterior interface depending on at least one information; determining a reference point of an axis of symmetry of the depth relief or of a respective anterior or posterior interface by means of the control device; and controlling the laser starting from the reference point in substantially circle-like tracks at least in certain areas such that the laser emits pulsed laser pulses in a shot sequence in a predefined pattern into the material, wherein the anterior and posterior interfaces of the volume body to be separated are defined by the predefined pattern and the anterior and posterior interfaces are generated by interaction of each of the laser pulses with the material by generation of a plurality of cavitation bubbles along the substantially circle-like tracks.

2. The method according to claim 1, wherein the depth relief is determined at the posterior interface.

3. The method according to claim 1, wherein control data is generated such that the anterior interface is generated substantially parallel to a surface of the material.

4. The method according to claim 1, wherein spiral tracks or elliptical tracks are generated as the substantially circle-like tracks.

5. The method according to claim 1, wherein the reference point is determined depending on a thickest location of the volume body to be generated or a thinnest location of the volume body to be generated.

6. The method according to claim 5, wherein a mathematical minimizing method for minimizing an asymmetry of the depth relief is used for determining the reference point.

7. The method according to claim 1, wherein control data is generated for removing the volume body in an eye and/or in a cornea of a human or an animal.

8. The method according to claim 7, wherein a potential position change of the eye in relation to the laser and/or a potential position change of the laser in relation to the eye are taken into account in controlling the laser.

9. The method according to claim 1, wherein the reference point is determined as a beginning of the substantially circle-like tracks or as an end of the substantially circle-like tracks.

10. The method according to according claim 1, wherein the reference point is determined such that the reference point does not coincide with a center of symmetry of the volume body viewed in a direction of the plurality of cavitation bubbles to be generated.

11. The method according to claim 1, wherein a shape of a patient interface of the processing apparatus for docking the material in a processing operation is taken into account in determining the reference point.

12. The method according to claim 1, wherein controlling the laser is effected such that a lenticular volume body is separated.

13. The method according to claim 1, wherein controlling the laser is effected such that topographic and/or pachymetric and/or morphologic data of the material is taken into account.

14. The method according to claim 1, wherein controlling the laser is effected such that the laser emits laser pulses in a wavelength range between 300 nm and 1400 nm, or between 700 nm and 1200 nm, at a respective pulse duration between 1 fs and 1 ns, or between 10 fs and 10 ps, and a repetition frequency of greater than 10 kHz, or between 100 kHz and 10 MHz.

15. A processing apparatus with at least one laser for separation of a volume body with predefined interfaces from a material by means of photodisruption or ablation and with at least one control device for the at least one laser that is configured to execute the the method according to claim 1.

16. The processing apparatus according to claim 15, wherein the control device comprises at least one storage device for at least temporary storage of at least one control dataset, wherein the at least one control dataset includes control data for positioning and/or for focusing individual laser pulses in the cornea; and includes at least one beam device for beam guidance and/or beam shaping and/or beam deflection and/or beam focusing of a laser beam of the at least one laser.

17. A computer program including commands, which cause a processing apparatus with at least one laser for separation of a volume body with predefined interfaces from a material by means of photodisruption or ablation and with at least one control device for the at least one laser to execute the method according to claim 1.

18. A non-transitory computer-readable medium, on which the computer program according to claim 17 is stored.

19. A method for performing a surgical procedure for separation from a material of a volume body with an anterior interface and with a posterior interface, wherein the method is executed by a control device of a processing apparatus and comprises: determining a depth relief of the volume body to be generated between the anterior interface and the posterior interface depending on at least one information; determining a reference point of an axis of symmetry of the depth relief or of a respective anterior or posterior interface by means of the control device; and controlling the laser starting from the reference point in substantially circle-like tracks at least in certain areas such that the laser emits pulsed laser pulses in a shot sequence in a predefined pattern into the material, wherein the anterior and posterior interfaces of the volume body to be separated are defined by the predefined pattern and the anterior and posterior interfaces are generated by interaction of each of the laser pulses with the material by generation of a plurality of cavitation bubbles along the substantially circle-like tracks.

20. The method for performing a surgical procedure according to claim 19, wherein the depth relief is determined at the posterior interface.

21. The method for performing a surgical procedure according to claim 19, wherein control data is generated such that the anterior interface is generated substantially parallel to a surface of the material.

22. The method for performing a surgical procedure according to claim 19, wherein spiral tracks or elliptical tracks are generated as the substantially circle-like tracks.

23. The method for performing a surgical procedure according to claim 19, wherein the reference point is determined depending on a thickest location of the volume body to be generated or a thinnest location of the volume body to be generated.

24. The method for performing a surgical procedure according to claim 23, wherein a mathematical minimizing method for minimizing an asymmetry of the depth relief is used for determining the reference point.

25. The method for performing a surgical procedure according to claim 19, the wherein control data is generated for removing the volume body in an eye and/or in a cornea of a human or an animal.

26. The method for performing a surgical procedure according to claim 25, wherein a potential position change of the eye in relation to the laser and/or a potential position change of the laser in relation to the eye are taken into account in controlling the laser.

27. The method for performing a surgical procedure according to claim 19, wherein the reference point is determined as a beginning of the substantially circle-like track or as an end of the substantially circle-like track.

28. The method for performing a surgical procedure according to claim 19, wherein the reference point is determined such that the reference point does not coincide with a center of symmetry of the volume body viewed in a direction of the plurality of cavitation bubbles to be generated.

29. The method for performing a surgical procedure according to claim 19, wherein a shape of a patient interface of the processing apparatus for docking the material in a processing operation is taken into account in determining the reference point.

30. The method for performing a surgical procedure according to claim 19, wherein controlling the laser is effected such that a lenticular volume body is separated.

31. The method for performing a surgical procedure according to claim 19, wherein controlling the laser is effected such that topographic and/or pachymetric and/or morphologic data of the material is taken into account.

32. The method for performing a surgical procedure according to claim 19, wherein controlling the laser is effected such that the laser emits laser pulses in a wavelength range between 300 nm and 1400 nm, or between 700 nm and 1200 nm, at a respective pulse duration between 1 fs and 1 ns, or between 10 fs and 10 ps, and a repetition frequency of greater than 10 kHz, or between 100 kHz and 10 MHz.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further features 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.

[0038] FIG. 1 is a schematic side view of an embodiment of a processing apparatus.

[0039] FIG. 2 is a further schematic side view of an embodiment of a processing apparatus.

[0040] FIG. 3 is a schematic sectional view of a material, in particular of an eye.

[0041] FIG. 4 is a schematic top view to an exemplary volume body.

[0042] In the figures, identical or functionally identical elements are provided with the same reference characters.

DETAILED DESCRIPTION

[0043] FIG. 1 shows a schematic representation of a processing apparatus 10 with a laser 18 for the separation of a predefined corneal volume or volume body 12. A cornea 44 (FIG. 3) comprises predefined interfaces 14, 16 (FIG. 2), wherein the cornea 44 is in particular that of a human or animal eye 42. The volume body 12 can be generated by means of photodisruption. Alternatively, the volume body 12 can also be removed by means of an ablative method. In particular, a posterior actual interface 14 and an anterior actual interface 16 of the cornea 44 are shown. One recognizes that a control device 20 for the laser 18 is formed besides the laser 18 such that it emits pulsed laser pulses for example in a predefined pattern into the cornea 44, wherein interfaces 14, 16 of the volume body 12 to be separated are generated by the predefined pattern for example by means of photodisruption. The processing apparatus 10 can also comprise further control devices. The interfaces 14, 16 of the volume body 12 form a lenticular volume body 12 in the illustrated embodiment, wherein the position of the volume body 12 is selected in this embodiment such that a pathological and/or unnaturally altered area 32 (see FIG. 2), for example a visual disorder, within a stroma 36 of the cornea 44 is enclosed. Furthermore, it is apparent from FIG. 1 that the so-called Bowman's membrane 38 is formed between the stroma 36 and an epithelium 28.

[0044] Furthermore, one recognizes that the laser beam 24 generated by the laser 18 is deflected towards a surface 26 of the cornea by means of a beam device 22, namely a beam deflection device, such as for example a rotation scanner (scanner, scanner device). The beam deflection device is also controlled by the control device 20 to generate the mentioned predefined pattern in the cornea.

[0045] The illustrated laser 18 is a photodisruptive laser or a laser 18, which is formed to emit laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 700 nm and 1200 nm, at a respective pulse duration between 1 fs and 1 ns, preferably between 10 fs and 10 ps, and a repetition frequency of greater than 10 kHz, preferably between 100 kHz and 100 MHz. Alternatively, the laser 18 can also be formed for removing the volume body 12 by an ablative method.

[0046] In addition, the control device 20 comprises a storage device (not illustrated) for at least temporary storage of at least one control dataset, wherein the control dataset or datasets include(s) control data for positioning and/or for focusing individual laser pulses in the cornea 44. The position data and/or focusing data of the individual laser pulses are generated based on a previously measured topography and/or pachymetry and/or the morphology of the cornea and the pathological and/or unnaturally altered area 32 for example to be removed or the optical visual disorder correction to be generated within the stroma 36 of the eye 42. Further, data, such as for example the shape and the position, of the posterior actual interface 14 of the cornea 44 and of the anterior actual interface 16 of the cornea 44 is also determined. Below, this data is also referred to as preset parameter.

[0047] FIG. 2 shows a schematic diagram of the generation of the volume body 12 to be separated according to an embodiment of the present method. One recognizes that the interfaces 14, 16 of the volume body 12 are generated by means of the pulsed laser beam 24, which is directed towards the cornea 44 or towards the surface 26 of the cornea 44 via the beam deflection device 22. Therein, the interfaces 14, 16 of the volume body 12 form a lenticular volume body 12, which for example encloses the pathological and/or unnaturally altered area 32 within the stroma 36. Furthermore, the laser 18 generates a further incision 34 in the illustrated embodiment, which intersects the volume body 12 at a predefined angle and with a predefined geometry and is formed up to the surface 26 of the cornea 44. The volume body 12 defined by the interfaces 14, 16 can then be removed from the cornea 44 via the incision 34. In the illustrated embodiment, the pathological and/or unnaturally altered area 32 is formed within the stroma 36 and outside of an optical axis 30 of the eye 42.

[0048] In the illustrated embodiment, the interface located deeper, that is the interface of the volume body 12 located deeper in the eye 42 and the stroma 36, respectively, can first be generated by means of the laser beam 24. This can be effected by at least partially circularly and/or spirally guiding the laser beam 24 according to the predefined pattern. Subsequently, the interface of the volume body 12 located higher is generated in comparable manner such that the interfaces 14, 16 form the lenticular volume body 12. Subsequently, the incision 34 is also generated by the laser 18. However, the order of the generation of the interfaces 14, 16 of the volume body 12 and of the incision 34 can also be changed.

[0049] FIG. 3 shows a schematic sectional view of the eye 44 with the volume body 12. In particular, it is shown that the volume body 12 comprises the anterior interface 16 as well as the posterior interface 14. Presently, the eye 44 in particular corresponds to a material. In the present embodiment, the anterior interface 16 is in particular formed substantially parallel to a surface 46 of the eye 44. The posterior interface 14 in turn comprises a depth relief 48. The volume body 12 comprises a center 50 of symmetry. Further, a reference point 52 is shown.

[0050] In the method for controlling the laser 18 of the processing apparatus 10, the separation of the volume body 12 is effected such that the depth relief 48 of the volume body 12 to be generated between the anterior interface 16 and the posterior interface 14 is determined depending on the at least one information, in particular patient information. The reference point 52 of an axis of symmetry of the determined depth relief 48 or of a respective interface 14, 16 is determined by means of the control device 20. Then, controlling the laser 18 starting from the determined reference point 52 in tracks circle-like at least in certain areas is in turn effected such that it emits pulsed laser pulses in a shot sequence in a predefined pattern into the cornea 44, wherein the interfaces 14, 16 of the volume body 12 are defined by the predefined pattern and the interfaces 14, 16 are generated by means of an interaction of the individual laser pulses 40 with the cornea 44 by the generation of a plurality of cavitation bubbles 40 along the circle-like tracks. Therein, it can in particular be provided that the circle-like tracks are spiral tracks or elliptical tracks.

[0051] The point 50 of symmetry is in particular a point of symmetry, in particular viewed in x-y direction. The reference point 52 is in particular a center of symmetry with respect to the z-coordinate. In particular, as shown in FIG. 3, the reference point 52 is determined such that it does not coincide with the center 50 of symmetry of the volume body 12 viewed in the direction of the cavitation bubbles 40 to be generated.

[0052] In particular, that direction is to be understood by z-direction, which extends substantially parallel to the laser beam 24 and/or to an optical axis of the beam device 22 or laser device. The x-direction and the y-direction are then in turn to be regarded perpendicularly to the z-direction, wherein the x-direction is also formed perpendicularly to the y-direction.

[0053] Therein, it can be provided that the reference point 52 is for example determined depending on the thickest location of the volume body 12 to be generated or a thinnest location of the volume body 12. Further, it is in particular provided that a mathematical minimizing method for minimizing an asymmetry of the depth relief 48 is used for determining the reference point 52.

[0054] Furthermore, it can be provided that a potential position change of the eye 42 in relation to the laser 18 and/or a potential position change of the laser 18 in relation to the eye 42 are taken into account in controlling the laser 18.

[0055] As already mentioned, the reference point 52 can therein be considered as the beginning of the circle-like track or also as the end of the circle-like track.

[0056] Furthermore, it is shown in FIG. 3 that a shape of a patient interface 54 of the processing apparatus 10 for docking the eye 42 in the treatment is also taken into account in determining the reference point 52. In particular, a deformation of the eye 42 in docking to the patient interface 54 can be taken into account in determining the reference point 52.

[0057] FIG. 4 shows a top view to a volume body 12. In particular, a depth relief 48 is illustrated. For example, a first area 56 is not situated as deep in the cornea 44 as a second area 58. Furthermore, it can be provided that a third area 60 is in turn in the same depth as the first area 56. A fourth area 62 can in turn be situated deeper than the first area 56 and the second area 60, wherein the fourth area 62 is in turn situated higher than the third area 58. Further, a fifth area 64 is shown, which is in turn substantially on a same depth plane, and is for example situated higher than the areas 56, 58, 60, 62. In particular, a so-called Zernike polynomial is shown in FIG. 4.

[0058] Now, it is in particular provided that the reference point 52 is determined depending on the altitudes of these areas 56, 58, 60, 62 and is used as the start point or end point of the cavitation bubbles 40 to be generated, and not the center 50 of symmetry of the volume body 12 to be generated.