Method for providing control data for a laser of a treatment apparatus
An apparatus and method are disclosed for providing control data for a laser of a treatment apparatus for the correction of a cornea. The method includes determining a look-up table for preset corneal parameters by a corneal deformation model, wherein the cornea can be modeled in deformed and non-deformed states by the corneal deformation model. A value of at least one preset corneal parameter in the non-deformed state of the cornea is varied and an effect of this variation on values of the corneal parameters in the deformed state of the cornea is ascertained for determining the look-up table. The method further includes ascertaining a corneal value to be achieved from predetermined examination data, determining by the look-up table a deformation-corrected corneal value to be achieved for compensating for the deformation of the cornea, and providing control data, which uses the deformation-corrected corneal value for correcting the cornea.
1 . A method for providing control data for a laser of a treatment apparatus for a correction of a cornea of a human or animal eye, wherein the method comprises the following steps performed by a control device:
determining a look-up table for preset corneal parameters using a corneal deformation model for compensating for a deformation of the cornea, wherein the cornea can be modeled in a deformed state and a non-deformed state by the corneal deformation model, wherein a value of at least one preset corneal parameter in the non-deformed state of the cornea is varied and an effect of this variation on values of the corneal parameters in the deformed state of the cornea is ascertained for determining the look-up table;
ascertaining a corneal value to be achieved from predetermined examination data, which at least one of the preset corneal parameters is to take by a treatment with the treatment apparatus, and a preoperative value of the at least one preset and varied corneal parameter, which the cornea to be treated has in the non-deformed state before the treatment;
determining a deformation-corrected corneal value to be achieved for at least the one preset corneal parameter, which is required for generating the corneal value to be achieved considering the deformation of the cornea, depending on the look-up table and the preoperative value of the at least one preset and varied corneal parameter; and
providing control data for controlling the laser, which uses at least the deformation-corrected corneal value to be achieved of the at least one preset corneal parameter for correcting the cornea.
2 . The method according to claim 1 , wherein the corneal deformation model is based on the Euler-Bernoulli beam theory.
3 . The method according to claim 1 , wherein the value of the at least one preset corneal parameter is varied within a preset range of values for determining the look-up table, wherein the range of values comprises default values of the corneal parameter.
4 . The method according to claim 1 , wherein a fit function, in particular a second order polynomial, is adapted to the ascertained values of the respective corneal parameters for determining the look-up table.
5 . The method according to claim 1 , wherein the corneal parameters include a radius of curvature of an anterior corneal surface and/or an optical distance between the anterior corneal surface and a posterior corneal surface and/or a thickness of the cornea and/or a radial distance from a limbus to a center of the cornea and/or an optical distance between the anterior corneal surface and an anterior interface of a lenticule to be separated and/or a radius of the anterior interface of the lenticule to be separated and/or a transition zone and/or a thickness of the lenticule and/or a planned refractive power correction and/or a radius of curvature of a contact element and/or a relative thickness of the cornea and/or an incision angle of an incision cut.
6 . The method according to claim 1 , wherein a planned refractive power correction and/or a planned lenticule diameter are adapted by the look-up table.
7 . The method according to claim 1 , wherein a compensation value is provided from the deformed and non-deformed state of the cornea by the look-up table for each corneal parameter, wherein the respective corneal parameters are multiplied and/or added by means of the compensation value for determining the respective corneal values for compensating for the deformation of the cornea.
8 . The method according to claim 1 , wherein a deformation of the cornea, which is generated by a contact element, is compensated for by means of the look-up table, and/or wherein a deformation of the cornea, which is generated upon closing the cornea after removal of a lenticule from the cornea, is compensated for by means of the look-up table.
9 . A control device, which is configured to perform a method according to claim 1 .
10 . A treatment apparatus with at least one eye surgical laser for separation of a lenticule with predefined interfaces from a human or animal eye by cavitation bubbles and with at least one control device according to claim 9 .
11 . The treatment apparatus according to claim 10 , wherein the at least one eye surgical laser is suitable 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.
12 . The treatment apparatus according to claim 10 , 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 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 eye surgical laser.
13 . A non-transitory computer-readable medium, on which a computer program is stored, the computer program includes commands that cause the control device according to claim 9 to execute the method.