METHOD FOR PROVIDING CONTROL DATA OF AN EYE SURGICAL LASER OF A TREATMENT APPARATUS BASED ON A PATIENT-SPECIFIC PARAMETER SET; CONTROL DEVICE AS WELL AS TREATMENT APPARATUS

Abstract

A method for providing control data of an eye surgical laser of a treatment apparatus is disclosed for a treatment on a human or animal eye. The method optimizes a target conflict between low stress for a patient and efficacy of a laser. The method includes, as performed by a control device, determining a patient-specific parameter set, which relates to at least one physiological characteristic of the eye, determining at least one physical parameter for the eye surgical laser depending on the patient-specific parameter set, wherein the physical parameter relates to a physical characteristic of a laser beam of the laser, and providing control data for controlling the eye surgical laser, which includes the physical parameter.

Claims

1. A method for providing control data of an eye surgical laser of a treatment apparatus for a treatment on a human or animal eye, wherein the method comprises the following steps performed by a control device: determining a patient-specific parameter set, which relates to at least one physiological characteristic of the eye; determining at least one physical parameter for the eye surgical laser depending on the patient-specific parameter set, wherein the physical parameter relates to a physical characteristic of a laser beam of the laser; and providing control data for controlling the eye surgical laser, which includes the physical parameter.

2. The method according to claim 1, wherein the additional steps of: providing a patient-unspecific parameter set, which is based on a cross-section of a plurality of patients and includes at least one standard value for at least one physiological characteristic of the eye; and determining a deviation between the patient-unspecific parameter set and the patient-specific parameter set, wherein determining the at least one physical parameter is effected at least depending on the deviation.

3. The method according to claim 1, wherein determining the at least one physical parameter is effected based on a model of the eye, which is adapted to the patient based on the patient-specific parameter set starting from a basic model.

4. The method according to claim 3, wherein depending on a type of a planned treatment on the eye, a respectively different model for determining the at least one physical parameter is used.

5. The method according to claim 1, wherein a respective value for a wavelength and/or a pulse duration and/or a pulse energy is determined as the at least one physical parameter.

6. The method according to claim 5, wherein determining the at least one physical parameter is effected depending on an angle of incidence of the laser beam on a surface of the eye, wherein the pulse energy is greater when the angle of incidence is flatter.

7. The method according to claim 5, wherein a value with respect to a moisture content of the eye is determined as the at least one physiological characteristic of the eye, and wherein when a higher pulse energy is determined the moisture content of the eye represented by the value is greater.

8. The method according to claim 5, wherein the pulse energy is determined depending on a refraction to be corrected by the treatment, wherein in the treatment of myopia, when a smaller pulse energy is determined, the refraction to be corrected is greater, and/or in the treatment of hyperopia, when a greater pulse energy is determined, the refraction to be corrected is greater.

9. The method according to claim 5, wherein in case of an ablation, the pulse energy is predominantly patient-specifically adapted, and/or in case of a photodisruption, the pulse duration is predominantly patient-specifically adapted.

10. A control device, which is formed to perform a method according to claim 1.

11. A treatment apparatus with at least one eye surgical laser for performing a corneal correction on a cornea by a control device according to claim 10.

12. The treatment apparatus according to claim 11, 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.

13. The treatment apparatus according to claim 11, 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 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 laser.

14. A computer program including commands, which cause a treatment apparatus with at least one eye surgical laser for performing a corneal correction on a cornea by a control device to execute a method according to claim 1.

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

16. The treatment apparatus according to claim 11, wherein the laser is formed to emit laser pulses in a wavelength range between 700 nm and 1200 nm, at a respective pulse duration of between 10 fs and 10 ps, and a repetition frequency of between 100 kHz and 100 MHz.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0032] 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. There show:

[0033] FIG. 1 a schematic representation of a treatment apparatus according to the invention according to an exemplary embodiment; and

[0034] FIG. 2 a flow diagram of a method according to the invention according to an exemplary embodiment.

DETAILED DESCRIPTION

[0035] FIG. 1 shows a schematic representation of a treatment apparatus 10 with an eye surgical laser 12 for the removal of a tissue 14 of a human or animal eye 16 by means of photodisruption and/or photoablation. For example, the tissue 14 can represent a lenticule or also volume body, which can be separated from a cornea of the eye 16 for correcting a visual disorder by the eye surgical laser 12. A geometry of the tissue 14 to be removed, thus a tissue removal geometry 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 in a pattern predefined by the control data into the cornea of the eye 16 to remove the tissue 14. Alternatively, the control device 18 can be a control device 18 external with respect to the treatment apparatus 10.

[0036] Furthermore, FIG. 1 shows that the laser beam 19 generated by the laser 12 can be deflected towards the eye 16 by means of a beam deflection device 22, namely a beam deflection apparatus such as for example a rotation scanner, to remove the tissue 14. The beam deflection apparatus 22 can also be controlled by the control device 18 to remove the tissue 14.

[0037] Preferably, the illustrated laser 12 can 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. The position data and/or focusing data of the individual laser pulses, that is the tissue removal geometry 14, are ascertained based on the method described below.

[0038] FIG. 2 shows a flow diagram of an exemplary embodiment of a method for providing control data of the eye surgical laser 12 of the treatment apparatus 10. Therein, the control data of the eye surgical laser 12 of the treatment apparatus 10 is determined for a corneal correction depending on an externally determined correction value. Based on the control data, thus, the corneal correction can be performed. In other words, the eye surgical laser 12 and the treatment apparatus 10, respectively, perform the corresponding corneal correction determined depending on the correction value in a control according to the control data generated by means of the method.

[0039] Therein, the method exemplarily comprises the following steps performed by the control device 18: Step S1: Determining a patient-specific parameter set, which relates to at least one physiological characteristic of the eye 16, Step S2: Providing S2 a patient-unspecific parameter set, which is based on a cross-section of a plurality of patients and includes at least one standard value for the at least one physiological characteristic of the eye 16, and Step S3: Determining a deviation between the patient-unspecific parameter set and the patient-specific parameter set, Step S4: Determining at least one physical parameter for the eye surgical laser 12 depending on the patient-specific parameter set, wherein the physical parameter relates to a physical characteristic of a laser beam 19 of the laser 12, wherein determining the at least one physical parameter is effected at least depending on the deviation, and Step S5: Providing control data for controlling the eye surgical laser 12, which includes the physical parameter.

[0040] Determining the patient-specific parameter set can include determining one or multiple patient-specific parameters. The one or the multiple patient-specific parameters are presently determined by a determination apparatus 20. The determination apparatus 20 can be a part of the treatment apparatus 10 and/or a part of the control device 18. The one or the multiple patient-specific parameters each individually or collectively relate to one or multiple physiological characteristics of the eye 16. Exemplary physiological characteristics of the eye 16, which can be described by the patient-specific parameter set, are a reflectivity of a surface of the eye, a moisture content of the eye 16, a size and a diameter, respectively, or a radius of an already present or planned optical zone of the eye, a degree of myopia or hyperopia, an age of the patient, a sensitivity of a tissue of the eye or the cornea with respect to a laser pulse and/or the like.

[0041] For example, the determination apparatus 20 can comprise a measurement unit for measuring or estimating the moisture content of the eye 16. Alternatively, the moisture content of the eye 16 can be derived or estimated at least from the age of the patient. This can be effected based on a predetermined formula. For example, the age of the patient can be derived from a user input of a user, in particular a physician. The user input can be received by the determination apparatus 20 for example from a patient database or an input appliance. Calculations underlying hereto can for example be performed by a microprocessor, a digital signal processor (DSP), an FPGA or the like of the determination apparatus 20 and/or control unit 18.

[0042] Size and/or diameter and/or radius of the planned optical zone for the eye 16 can for example be derived from ablation data and/or photodisruption data. Based on the ablation data and/or photodisruption data, the refraction to be corrected by the treatment can additionally be determined. Similarly, it can be determined if the visual disorder to be corrected is myopia or hyperopia. The ablation data and photodisruption data, respectively, describe and quantify, respectively, a presently planned ablation and photodisruption, respectively, for correcting the refraction or the visual disorder (thus for example the myopia or hyperopia). The ablation data can for example be an ablation map. In the present example, it is provided that determining the at least one physical parameter is effected depending on an angle of incidence of the laser beam 19 on a surface of the eye 16. The angle of incidence of the laser beam 19 can be derived from the size and/or the diameter and/or the radius of the planned optical zone for the eye 16. Therein, a flatter angle of incidence usually results from a larger optical zone. Calculations underlying hereto can for example be performed by the microprocessor, the digital signal processor (DSP), the FPGA or the like of the determination apparatus 20 and/or control unit 18.

[0043] The patient-unspecific parameter set can include an average value for the at least one physiological characteristic of the eye for the plurality of patients as the standard value. For example, the patient-unspecific parameter set can be retrieved from a model database 22. Of course, the patient-unspecific parameter set can include a respective or multiple respective standard values for different or multiple physiological characteristics. Therein, the standard value can present or represent an average value, a median value, an accumulation value or any other value describing the plurality of patients on average. In other words, the at least one physiological characteristic of the eye in cross-section of the plurality of patients can be described by the standard value. In case of multiple standard values, which are part of the patient-unspecific parameter set, each of the standard values can relate to or describe a respective physiological characteristic of the eye in cross-section of the plurality of patients. Since the standard value or the standard values is/are related to a plurality of patients, the designation is effected as patient-unspecific. In contrast thereto, the patient-specific parameter set is specific to a respective patient.

[0044] In determining the deviation between the patient-unspecific parameter set and the patient-specific parameter set, it can be determined how far the patient-specific parameters deviate from the respective standard value for the same physiological characteristic of the eye. In this manner, the deviation can specify, how severely the at least one physiological characteristic of the eye coincides with the cross-section of the plurality of patients. Therein, the deviation can be represented by a single numerical value or by a matrix or the like.

[0045] The model database 22 can contain one or multiple biophysical models of an eye. Based on the patient-specific parameter set, the respective model can be adapted to the individual patient. In other words, the respective model can be parameterizable based on the parameters of the patient-specific parameter set. Thereby, a deviation between a standard basic model and the patient-specific parametrized model can be determined on the one hand. This deviation can be used for determining a patient-specific adaptation starting from the standard basic model alternatively or additionally to the above mentioned deviation between the patient-unspecific parameter set and the patient-specific parameter set. The standard basic model can for example be parameterized by the patient-unspecific parameter set. Alternatively, or additionally, the patient-specifically parametrized model can be used to simulate an influence of the physical parameter and of patient-specific adaptations of the physical parameter, respectively.

[0046] Therein, it is in particular provided that depending on a type of the planned treatment on the eye 16, a respectively different model is applied or used. In particular, a respectively different basic model is provided for different treatments on the eye 16. Depending on the planned treatment on the eye, a basic model specific to the respective treatment can be selected from multiple basic models and adapted to the patient corresponding to the above mentioned parameterization. The different models or different basic models for different types of the treatment can each consider different influencing factors, different patient-specific parameters and/or physiological characteristics of the eye. Thus, the model is adapted to the treatment respectively to be performed to a particular degree.

[0047] For example, the physical parameter can be determined starting from a standard value. For example, the standard value can be preset or get preset for the physical parameter. The patient-specific determination of the physical parameter depending on the deviation can then be effected such that the at least one physical parameter is derived from the standard value for the corresponding physical parameter depending on the deviation between the patient-unspecific parameter set and the patient-specific parameter set and/or the deviation between the standard model and the patient-specifically parameterized model.

[0048] Presently, a wavelength as well as a pulse duration and a pulse energy are determined as the respective physical parameter. In other words, the physical parameter can preset the wavelength for the laser beam 19. Alternatively, or additionally, the physical parameter can preset the pulse duration for the laser beam 19. Alternatively, or additionally, the physical parameter can preset the pulse energy for the laser beam 19.

[0049] Presently, the determination of the physical parameter, in particular of the pulse energy, is effected depending on the angle of incidence of the laser beam 19 on a surface of the eye 16. Therein, it can in particular be provided that the pulse energy is the greater, the flatter the angle of incidence is. Conversely, the pulse energy can be the smaller, the steeper the angle of incidence is. As described above, the angle of incidence of the laser beam 19 is derived based on the size of the optical zone to be generated by the treatment. In this manner, it can be taken into account that the angle of incidence becomes increasingly flatter with increasing size of the optical zone. In this manner, a correlation between the size of the optical zone and the pulse energy of the laser beam can arise. Therein, the pulse energy is advantageously the greater, the larger the optical zone is.

[0050] Presently, the determination of the physical parameter, in particular of the pulse energy, is effected depending on the moisture content of the eye 16. Therein, it is in particular provided that an all the higher pulse energy is determined, the greater the moisture content of the eye is. Alternatively, or additionally, the moisture content or the value can be derived from the age of the patient. This is based on the realization that the moisture content of the eye usually increases with increasing age of the patient. The moisture content of the eye can be derived based on the age or represented by the age statement. This in particular means that the pulse energy of the laser beam is selected the higher, the older the patient is.

[0051] Presently, the determination of the physical parameter, in particular of the pulse energy, is effected depending on the refraction to be corrected by the treatment. Therein, it can in particular be provided that in case of the treatment of myopia, an all the smaller pulse energy is determined, the greater the refraction to be corrected is. Alternatively, or additionally, it can be provided that in case of the treatment of hyperopia, an all the greater pulse energy is determined, the greater the refraction to be corrected is.

[0052] Overall, it is shown by the embodiment, how the treatment can be adapted to the patient in automated manner to a high degree. Thereby, a particularly high efficiency of the treatment can be particularly well associated with a stress for the patient as low as possible.

LIST OF REFERENCE CHARACTERS

[0053] 10 Treatment apparatus [0054] 12 laser [0055] 14 tissue [0056] 16 eye [0057] 17 beam deflection device [0058] 18 control device [0059] 19 laser beam [0060] 20 determination apparatus [0061] 22 model database [0062] S1 . . . S5 method steps