METHOD FOR CONTROLLING AN OPTHALMOLOGICAL LASER AND TREATMENT APPARATUS

Abstract

The invention relates to a method for controlling an ophthalmological laser (12) of a treatment apparatus (10) for the treatment of a human or animal eye (16), comprising controlling the laser (12) by means of a control device (18) of the treatment apparatus (10) such that it emits pulsed laser pulses (20) in a shot sequence in a preset pattern into the eye (16), wherein the individual laser pulses interact with a tissue (14) of the eye for the treatment of the eye (16), wherein a space-filling curve is preset for the pattern for treating the tissue (14).

Claims

1. A method for controlling an ophthalmological laser of a treatment apparatus for the treatment of a human or animal eye, comprising: controlling the laser using a control device of the treatment apparatus such that the laser emits pulsed laser pulses in a shot sequence in a preset pattern into the eye, wherein the individual laser pulses interact with a tissue of the eye for the treatment of the eye, wherein a space-filling curve is the preset pattern for the treatment of the tissue.

2. The method according to claim 1, wherein the space-filling curve is shaped in a self-avoiding manner.

3. The method according to claim 1, wherein the space-filling curve is a fractal.

4. The method according to claim 3, wherein the fractal is one of a Gosper curve, a Hilbert curve or a Peano curve.

5. The method according to claim 1, wherein the laser is controlled such that the laser pulses generate the space-filling curve in a continuous manner.

6. The method according to claim 1, wherein the laser is controlled such that the laser pulses generate the space-filling curve line by line or in a concentric or spiral manner.

7. The method according to claim 1, wherein the laser pulses are emitted into a cornea and/or a lens of the eye.

8. A control device, which is configured to perform a method according to claim 1.

9. A treatment apparatus with at least one ophthalmological laser for the treatment of a human or animal eye using photodisruption and/or photoablation and/or a laser induced refractive index change, and at least one control device according to claim 8.

10. The treatment apparatus according to claim 9, wherein the laser is formed to emit laser pulses in a wavelength range between 300 nm and 1400 nm, at a respective pulse duration between 1 fs and 1 ns, and a repetition frequency of greater than 10 kHz.

11. The treatment apparatus according to claim 9, wherein the laser is formed to emit laser pulses in a wavelength range between 150 nm and 250 nm, at a respective pulse duration between 1 fs and 100 ns, and a repetition frequency of greater than 100 Hz.

12. The treatment apparatus according to claim 9, wherein the control device comprises at least one storage device 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 focusing individual laser pulses in the eye; and the treatment device further includes at least one beam deflection device for beam guidance and/or beam shaping and/or beam deflection and/or beam focusing of a laser beam of the laser.

13. (canceled)

14. (canceled)

15. The treatment apparatus according to claim 10, wherein the laser is formed to emit laser pulses in a wavelength between 700 nm and 1200 nm, at a respective pulse duration between 10 fs and 10 ps, and a repetition frequency between 100 kHz and 100 MHz.

16. The treatment apparatus according to claim 11, wherein the laser is formed to emit laser pulses in a wavelength between 175 nm and 215 nm, at a respective pulse duration between 10 ps and 10 ns, and a repetition frequency between 400 Hz and 10 kHz.

17. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause a treatment apparatus, which includes at least one ophthalmological laser for the treatment of a human or animal eye by means of photodisruption and/or photoablation and/or a laser induced refractive index change and at least one control device, to execute a method comprising: controlling the at least one laser using the at least one control device of the treatment apparatus such that the laser emits pulsed laser pulses in a shot sequence in a preset pattern into the eye, wherein the individual laser pulses interact with a tissue of the eye for the treatment of the eye, and wherein a space-filling curve is the preset pattern for the treatment of the tissue.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0023] 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.

[0024] FIG. 1 depicts a schematically illustrated treatment apparatus according to an exemplary embodiment.

[0025] FIG. 2 depicts a section of a schematically illustrated treatment apparatus according to an exemplary embodiment.

[0026] In the figures, identical or functionally identical elements are provided with the same reference characters.

DETAILED DESCRIPTION

[0027] FIG. 1 shows a schematic representation of a treatment apparatus 10 with an ophthalmological laser 12 for the treatment of an eye 16, wherein a tissue 14, in particular a volume body 14, is removed from a human or animal cornea by means of photodisruption and/or photoablation in this embodiment. For example, the volume body 14 can be separated from a cornea of an eye 16 for correcting a visual disorder by the eye surgical laser 12. A predefined pattern for removing the volume body 14 can be provided by a control device 18, in particular in the form of control data, such that the laser 12 emits pulsed laser pulses into the cornea of the eye 16 in a pattern predefined by the control data, to form an anterior interface and a posterior interface, which together result in the volume body 14. Alternatively, the control device 18 can be a control device 18 external with respect to the treatment apparatus 10.

[0028] Furthermore, FIG. 1 shows that the laser beam 20 generated by the laser 12 can be deflected towards the cornea 16 by means of a beam deflection device 22, such as for example a rotation scanner, to separate the volume body 14. The beam deflection device 22 can also be controlled by the control device 18 to remove the volume body 14.

[0029] The illustrated laser 12 can preferably be a photodisruptive and/or photoablative laser, which is formed to emit laser pulses in a wavelength range between 300 nanometers and 1400 nanometers, preferably between 700 nanometers and 1200 nanometers, at a respective pulse duration between 1 femtosecond and 1 nanosecond, preferably between 10 femtoseconds and 10 picoseconds, and a repetition frequency of greater than 10 kilohertz, preferably between 100 kilohertz and 100 megahertz. Optionally, the control device 18 additionally 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.

[0030] One problem in the removal of the volume body 16 with conventional approaches is in that undesired diffraction errors can occur. In particular if concentric paths are used for the preset pattern, it can result in multifocal effects, which can impair a vision. Therefore, it is provided that a space-filling, preferably self-avoiding, simple and self-similar curve is used for the control of the laser 12. In particular fractals satisfy this characteristic and are particularly suitable to avoid a development of microlenses during the treatment.

[0031] In FIG. 2, it is schematically illustrated how the treatment apparatus 10 can remove the volume body 14, in particular a respective interface of the volume body 14, by means of a preset fractal pattern. Herein, the laser 12 irradiates pulsed laser pulses 20, which are irradiated into the eye 16 via the beam deflection device 22. Control data can be stored in the control device 18, which control the beam deflection device 22 such that the laser beam generates the fractal pattern. In this example, a Gosper curve can be generated in a posterior and in an anterior surface, whereby the lenticule 14 can be subsequently removed.

[0032] For generating the fractal, the fractal curve can be generated by the beam deflection device 22 in continuous manner, that means that the laser beam 20 can be guided along the path of the fractal curve. Alternatively, the control device can also scan the interface to be removed line by line, in spiral or concentric manner, wherein the laser 12 can preferably be configured such that the laser pulses of the laser beam 20 are only irradiated if the current position matches the curve of the fractal. This has the advantage that the space-filling curve can be faster generated since the beam deflection device 22 can be simpler controlled.

[0033] Here, the control of the laser 12 was described based on the example of an incision in the cornea for removing a volume body 14. The use of space-filling curves, in particular of a fractal, as a preset pattern, can also be applied in laser induced refractive index change, in which a lens of the eye can also be irradiated besides the cornea to obtain a refractive index change. In particular, cavitation bubbles are not generated in this URIC method, but one achieves a refractive index change by molecular changes in the tissue.

[0034] Overall, the examples show how a regularly arranged diffraction structure can be interrupted by the invention in that virtually irregular structures are scanned by fractal scan patterns. In incisions, such curves can be scanned to generate the incision surfaces without the above mentioned side effects. In LIRIC applications too, such curves can be scanned to still achieve the desired characteristics of an extensive index change or a Fresnel lens.