Method for providing control data for an ophthalmic laser of a treatment device, control device, treatment device, computer program and computer-readable medium

Abstract

The invention relates to a method for providing control data for an ophthalmic laser (12) of a treatment device (10), wherein the method comprises the following steps, carried out by a control device (18): specifying eye information (56) of an eye (14) to the control device (18); determining a target zone (46) between a Bowman membrane (36) of the eye (14) and an endothelium (42) of the eye (14); specifying an error value (58) for generating a laser pulse to the control device (18); and determining an effective target depth (64) for the laser (12) as a function of the determined target zone (46) and as a function of the specified error value (58). The invention further relates to a method for controlling a treatment device (10), a control device (12), a treatment device (10), a computer program, and a computer-readable medium.

Description

[0001] The invention relates to a method for providing control data for an ophthalmic laser of a treatment device according to the applicable patent claim 1. Furthermore, the invention relates to a control device, a treatment device, a computer program and a computer-readable medium.

[0002] Clouding and scarring within the cornea, also known as the cornea, which can result from inflammation, injury, or congenital diseases, impair vision. Clear vision is significantly impaired, particularly when these pathological and / or abnormally altered areas of the cornea lie in the eye's visual axis. Furthermore, other visual disorders, such as reduced visual acuity or corneal curvature, can also impair vision. Various state-of-the-art laser procedures using appropriate treatment devices are available for this purpose. These can detach a solid body from the cornea and thus improve vision for a patient.For example, photodisruptive and ablative procedures are known for this purpose, which create corresponding interfaces via laser pulses and can thus, for example, remove a volume body from the cornea, whereby the injured or diseased area can be changed in such a way that vision is improved again.

[0003] The object of the present invention is to provide a method, a control device, a treatment device, a computer program and a computer-readable medium by means of which a treatment device can be operated reliably.

[0004] This object is achieved by the method according to the invention, the devices according to the invention, the computer program according to the invention, and the computer-readable medium according to the invention. Advantageous embodiments with expedient refinements of the invention are specified in the respective subclaims, wherein advantageous embodiments of the method are to be regarded as advantageous embodiments of the treatment device, the control device, the computer program, and the computer-readable medium, and vice versa.

[0005] A first aspect of the invention relates to a method for providing control data for an ophthalmic laser of a treatment device, wherein the method comprises the following steps performed by the control device: Eye information of an eye is provided to the control device. A target zone between a Bowman's membrane of the eye and an endothelium of the eye is determined. An error value for generating a laser pulse is provided to the control device. An effective target depth for the laser is determined as a function of the determined target zone and as a function of the specified error value.

[0006] In particular, this has the advantage of allowing reliable determination of control data, which can then be imaged in the target zone, which primarily forms the stroma. This prevents, in particular, incisions made with the laser that are too shallow, which could, for example, damage the Bowman's membrane. Furthermore, incisions that are too deep, which could, for example, damage the eye's endothelium, can also be prevented.

[0007] In the prior art, the target depth of action is set manually by a corresponding practitioner. This can lead to corresponding injuries to the Bowman membrane or the endothelium during treatment. According to the invention, the target depth of action is now specified by the electronic computing device or treatment device. In particular, an error value, for example an error value of the treatment device, is taken into account so that only incisions located between the Bowman membrane and the endothelium can be reliably created. In particular, the so-called stroma, in which the treatment is to be performed, is located between the Bowman membrane and the endothelium.

[0008] Thus, the method according to the invention prevents the creation of incisions that are too deep or too high. This allows for reliable patient treatment based on the generated control data.

[0009] According to an advantageous embodiment, patient-specific ocular information is provided. For example, the patient can be examined accordingly in a preliminary examination, and, for example, the exact position of the Bowman membrane, the thickness of the stroma, and the exact position of the endothelium can be recorded accordingly. Based on this recorded data, the ocular information can then be reliably provided, allowing the control data for the treatment to be generated on a person-specific basis. This allows subsequent treatment to be carried out on a person-specific basis.

[0010] A further advantageous embodiment provides for generic eye information to be specified for a human eye and / or an animal eye. If, for example, no prior examination of a patient has been performed, generic eye information can be assumed. In particular, it can be assumed that, for example, the position of the Bowman membrane, the position of the endothelium, and the thickness of the stroma are generically specified accordingly. Thus, the procedure can be performed reliably even without a corresponding prior examination.

[0011] It is also advantageous if a treatment device-specific error value is specified. In particular, the standard deviation of the treatment device can be considered as an error value. For example, each treatment device has a type-specific error value. This can be determined using appropriate measurement methods. Depending on the treatment device-specific error value, the corresponding target depth or target zone can then be reliably determined.

[0012] A further advantageous embodiment provides for a type-specific error value to be specified for the treatment device. A type-specific error value is understood, in particular, to mean that a type of treatment device has a corresponding error value. In particular, a type-specific error value is thus generically specified. Thus, even without individual measurement of the treatment device, the error value can still be reliably specified, and a reliable generation of control data for the treatment can be realized.

[0013] In a further advantageous embodiment, a minimum effective target depth for the laser is determined as the cutting depth. In particular, this allows the minimum target zone for the laser pulses to be specified. This, in particular, prevents the Bowman membrane from being damaged. In particular, the minimum depth depends on the specific Bowman membrane. This prevents damage to the Bowman membrane.

[0014] It is also advantageous if control data is generated for creating a lenticule to be removed. In particular, the laser pulses can be generated in such a way that, for example, cavitation bubbles are generated based on photodisruption, which in turn create a lenticule in the cornea. The lenticule can then be removed from the eye via a corresponding incision. This provides control data for creating a lenticule.

[0015] A further advantageous embodiment provides that the control data are generated in such a way that an anterior boundary surface of the lenticule is created at the effective target depth. In particular, the posterior boundary surface can then also be created depending on the anterior boundary surface. In other words, the effective target depth then describes the anterior boundary surface of the lenticule. The anterior boundary surface is in particular a boundary surface facing away from the inner sides of the eye. In particular, the anterior boundary surface faces the Bowman membrane. The posterior boundary surface faces the endothelium. By determining the target zone for the anterior boundary surface, the Bowman membrane can be prevented from being damaged accordingly.

[0016] It is also advantageous if control data for preparing a corneal lamella is generated. A corneal lamella is, in particular, a treatment in which a corresponding flat is created, which is then removed from the eye to remove the corresponding corneal volume. In particular, the method can thus also be reliably used for creating the corneal lamella.

[0017] It has also proven advantageous to change the refractive index in the target zone at the target depth based on the laser pulses. In other words, the corresponding lenticule is not removed; instead, the refractive index is changed within the cornea. This procedure can now prevent, for example, the refractive index from being changed not in the stroma, but in the Bowman membrane or endothelium. Thus, reliable treatment can also be performed based on the change in the refractive index.

[0018] It has also proven advantageous to generate the control data in such a way that cross-linking of the cornea is achieved. This is particularly a so-called cross-linking procedure. Cross-linking of the cornea is a means of halting the progressive effects of keratoconus on the cornea. Cross-linking is a method for mechanically stabilizing tissues, particularly the stroma. This can prevent, for example, laser pulses from being transmitted to create cross-linking in the Bowman membrane or endothelium.

[0019] It is also advantageous if the effective target depth is determined based on three times the standard deviation of the error value and the Bowman membrane. In particular, the target zone can be determined at a distance of at least three times the error value from the Bowman membrane. This can be, for example, between 20 and 25 micrometers, particularly when viewed from the Bowman membrane toward the interior of the eye. This allows for reliable patient treatment.

[0020] A further advantageous embodiment provides that the effective target depth is determined as a function of nine times the standard deviation of the error value and the Bowman membrane. For example, nine times the standard deviation is a corresponding minimum value for treatment. In other words, it is specifically provided that the target zone is determined between three times the standard deviation and nine times the standard deviation. This reliably prevents injury to the Bowman membrane and the endothelium.

[0021] It has also proven beneficial to consider potential future treatment options. In particular, should future treatment also be necessary, the effective zone can be defined in such a way that future treatment is still possible in the stroma, allowing, for example, the removal of another lenticule in the future. In particular, the treatment can be performed at a corresponding minimum depth in the stroma, so that there will still be material available for removal in the future. This allows future treatment options to be considered.

[0022] It is also advantageous to consider previous treatments. If, for example, this is a second treatment, the target zone definition can be adjusted accordingly, for example, to maintain a suitable distance from the previously treated zone within the stroma.

[0023] It has also proven advantageous to issue a warning message when the target depth of action is exceeded. In particular, for example, the warning message can be issued if the target depth of action is determined to be above three times the standard deviation for the Bowman membrane and below nine times the standard deviation for the endothelium. This allows the operator of the treatment device to be reliably warned that they are outside the target depth of action, thus preventing corresponding patient injury.

[0024] A second aspect of the invention relates to a method for controlling a treatment device, wherein the method comprises carrying out the method steps of a method according to the first aspect and transmitting the provided control data to a respective ophthalmic surgical laser of the treatment device.

[0025] The control data may include a respective data set for positioning and / or focusing individual laser pulses in the cornea. Additionally or alternatively, the control data may include a respective data set for adjusting 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 respective laser.

[0026] The respective method may include at least one additional step that is executed precisely when a use case or application situation occurs that has not been explicitly described here. The step may, for example, include outputting an error message and / or a request for user feedback. Additionally or alternatively, provision may be made for setting a default setting and / or a predetermined initial state.

[0027] A third aspect of the invention relates to a control device which is designed to carry out the steps of at least one embodiment of one or both of the methods described above. For this purpose, the control device can have a computing unit for electronic data processing, such as a processor. The computing unit can comprise at least one microcontroller and / or at least one microprocessor. The computing unit can be embodied as an integrated circuit and / or microchip. Furthermore, the control device can comprise an (electronic) data memory or a memory unit. Program code which encodes the steps of the respective embodiment of the respective method can be stored on the data memory. The program code can comprise the control data for the respective laser.The program code can be executed by the computing unit, causing the control device to execute the respective embodiment. The control device can be embodied as a control chip or control unit. The control device can, for example, be comprised of a computer or computer network. It is understood that multiple control devices can also be provided, which can then, in turn, carry out the method.

[0028] A fourth aspect of the invention relates to a treatment device comprising at least one ophthalmic or ophthalmic laser and a control device configured to perform the steps of at least one embodiment of one or both of the previously described methods. The respective laser can be configured to at least partially separate a predefined corneal volume with predefined interfaces of a human or animal eye by means of optical disruption, in particular to at least partially separate it by means of photodisruption and / or to ablate corneal layers by means of (photo)ablation and / or to cause a laser-induced refractive index change in the cornea and / or the lens of the eye.The treatment device thus comprises at least one ophthalmic surgical laser for separating a corneal volume with predefined boundary surfaces of a human or animal eye by means of optical disruption, in particular by means of photodisruption and / or photoablation, and at least one control device according to the third aspect of this invention.

[0029] It has also proven advantageous to generate the control data for laser pulses in a wavelength range between 200 nm and 2 µm, in particular between 400 nm and 1450 nm, with a respective pulse duration between 1 fs and 1 ps, in particular between 10 fs and 100 fs, and a repetition frequency greater than 10 kHz, in particular between 1 MHz and 100 MHz. In particular, this allows the laser pulses to be generated below the photodisruption regime, resulting only in a change in the refractive index. This allows the procedure, and in particular the change in the refractive index, to be reliably performed without performing an invasive procedure in the cornea.

[0030] In an advantageous embodiment of the treatment device, the treatment device comprises a storage device for at least temporarily storing at least one control data set, wherein the control data set(s) comprise control data for individual laser pulses on or in the optical element and comprise 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. Said control data sets are typically generated based on a measured topography and / or pachymetry and / or morphology of the optical element to be treated, in particular the cornea or lens to be treated in the pathologically and / or abnormally altered region within the optical element.

[0031] A fifth aspect of the invention relates to a computer program comprising instructions which cause the treatment device according to the fourth aspect of the invention to carry out a method according to the first aspect of the invention and / or according to a method according to the second aspect of the invention.

[0032] A further aspect of the invention relates to a computer-readable medium (storage medium) on which the aforementioned computer program or its instructions are stored. To execute the computer program, a computer or a computer network can access the computer-readable medium and read its contents. The storage medium is designed, for example, as a data memory, in particular at least partially as a volatile or non-volatile data memory. A non-volatile data memory can be a flash memory and / or an SSD (solid state drive) and / or a hard disk. A volatile data memory can be a RAM (random access memory). The instructions can be present, for example, as source code of a programming language and / or as assembler and / or as binary code.

[0033] Additional features and advantages of the invention are described below with reference to the figure(s) in the form of advantageous exemplary embodiments. The features or combinations of features of the exemplary embodiments described below can be present in any combination with one another and / or with the features of the embodiments. This means that the features of the exemplary embodiments can supplement and / or replace the features of the embodiments, and vice versa. Thus, embodiments are also to be considered encompassed and disclosed by the invention that are not explicitly shown or explained in the figures, but which emerge and can be produced through separate combinations of features from the exemplary embodiments and / or embodiments.Thus, embodiments are also considered to be disclosed that do not have all the features of an originally formulated claim or that go beyond or deviate from the combinations of features set out in the claims' references. In this case, the following are shown: . Fig. 1 is a schematic block diagram according to an embodiment of a treatment device; Fig. 2 a schematic sectional view of an embodiment of an eye; and Fig. 3 a schematic flow diagram according to an embodiment of the method.

[0034] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0035] Fig. 1 shows a schematic representation of a laser device 10 with a laser 12 for, for example, the treatment of a patient, in particular for the treatment of an eye 14 of a patient, wherein the eye 14 is also referred to below as an optical element. The laser device 10 is thus designed as an ophthalmic surgical treatment device. It can be seen that, in addition to the laser 12, a control device 18 for the laser 12 is designed. This embodiment with a control device 18 is to be regarded purely as an example. It can be provided that the laser device 10 also has a plurality, in particular more than two, control devices 18.The control device 18 can, for example, emit pulsed laser pulses in a predefined pattern into the eye 14, for example, into a region 16. In this exemplary embodiment, the position of the region 16 is selected such that a pathological and / or abnormally altered region is enclosed within a stroma of the eye 14. The region 16 is thus a region 16 to be treated.

[0036] Furthermore, it can be seen that the laser beam 22 generated by the laser 12 is deflected toward the eye 14 by a beam deflection device 24, such as a scanner, in particular a so-called rotary scanner. The beam deflection device 24 is also controlled by the control device 18, for example, to generate irradiation lines. The beam deflection device 24 can, for example, have one or two mirrors designed to deflect the incident laser beam 22.

[0037] In the present embodiment, the laser 12 shown is a laser 12 that emits laser pulses in a wavelength range between 200 nm and 2 µm, in particular between 400 nm and 1450 nm, with a respective pulse duration between 1 fs and 1 ps, in particular between 10 fs and 100 fs, and a repetition frequency greater than 10 kHz, in particular between 1 MHz and 100 MHz. In particular, this allows the laser pulses to be generated below the photodisruption regime, which merely leads to a change in the refractive index. This allows the method, and in particular the change in the refractive index, to be reliably performed without performing an invasive procedure, for example, in a cornea.

[0038] The control device 18 also has a memory device 28 for at least temporarily storing at least one control data set, wherein the control data set(s) comprise control data for positioning and / or focusing individual laser pulses in or on the eye 14. 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 eye 14 and, for example, the pathological and / or abnormally altered region within the stroma of the eye 14.

[0039] Fig. Figure 2 shows a schematic sectional view according to an embodiment of an eye 14. In the present embodiment, the structure of a human eye 14 is shown in particular. In particular, the Fig. 2 a lipid layer 20, an aqueous layer 26, a mucin layer 30, epithelial cells 34, a Bowman membrane 36, the stroma 38, a Descemet membrane 40 and endothelial cells, which are also referred to as endothelium 42.

[0040] Furthermore, the Fig. 2 in the stroma 38, a lenticule 44, which is to be removed, for example, from the region 16 in order to be able to carry out a corresponding treatment on the eye 14. Furthermore, a target zone 46 is shown, which is formed between the Bowman membrane 36 and the endothelium 42. For this purpose, a first distance 50 is provided, in particular, between a minimum target zone value 48, in particular relative to the Bowman membrane 36, and a maximum target zone value 52 is specified to the endothelium 42 or to the Descemet membrane 40, wherein in this case, in particular, a second distance 54 is set between the Descemet membrane 40.

[0041] Fig. 3 shows a schematic flow diagram according to one embodiment of the method. In particular, the control data for the ophthalmic laser 22 of the treatment device 10 are provided accordingly. The method is carried out in particular by the control device 18. In a first step S1, eye information 56 of the eye 14 is specified to the control device 18. In a second step S2, the target zone 46 between the Bowman membrane 36 of the eye 14 and the endothelium 42 is determined. In a third step S3, an error value 58 for generating a laser pulse is specified to the control device 18. The effective target depth 48, 52 is determined in a fourth step S4 for the laser 12 as a function of the determined target zone 46 and as a function of the specified error value 58.

[0042] In particular, it can be provided that patient-specific eye information 56 is specified. Alternatively or additionally, generic eye information 56 for a human eye and / or an animal eye can also be specified.

[0043] Furthermore, it can be provided that a treatment device-specific error value 58 is specified and / or a type-specific error value 58 is specified for the treatment device 10.

[0044] Furthermore, it can be provided in particular that a minimum effective target depth 48 for the laser 12 is determined as the cutting depth.

[0045] Furthermore, it can be provided that control data are generated for generating a lenticule 44 to be removed. In this case, the control data can be generated in such a way that an anterior boundary surface 60 ( Fig. 2) of the lenticule 44. The anterior interface 60 is again particularly directed towards the Bowman membrane 36. A posterior interface 62 ( Fig. 2) is again facing the endothelium 42.

[0046] In particular, the method can generate control data for preparing a corneal lamella. Furthermore, the method can also be provided for influencing a refractive index in the target zone 56 based on the laser pulses. Furthermore, the method can also be performed for cross-linking the cornea.

[0047] In particular, it can further be provided that the effective target depth 48, 42 is determined as a function of three times the standard deviation of the error value 58 and the Bowman membrane 36. In this case, the first distance 50 can, in particular, correspond to three times the standard deviation. Furthermore, it can be provided that the effective target depth 48, 52 is determined as a function of nine times the standard deviation of the error value 58 and the Bowman membrane 36. In this case, the second distance 54 can, in particular, correspond to nine times the standard deviation.

[0048] In particular, this can ensure that, for example, potential future treatment can also be taken into account. According to the Fig. 2, for example, a further lenticule can be produced in the future below the lenticule 44 shown, since there is still sufficient space within the stroma 38 for a further lenticule.

[0049] Furthermore, historical treatments can also be taken into account, for example the distance of a lenticule 44 already produced in the past can be taken into account accordingly.

[0050] If, for example, the target depth 48, 52 is undershot, a corresponding warning message can be issued. In particular, an undershot can be considered if, for example, the target depth is too close to the Bowman membrane 36 or too close to the endothelium 42.

Claims

[1] Method for providing control data for an ophthalmic laser (12) of a treatment device (10), the method comprising the following steps carried out by a control device (18): - Presetting eye information (56) of an eye (14) to the control device (18); - determining a target zone (46) between a Bowman membrane (36) of the eye (14) and an endothelium (42) of the eye (14); - specifying an error value (58) for the generation of a laser pulse to the control device (18); and - Determining an effective target depth (64) for the laser (12) as a function of the determined target zone (46) and as a function of the predetermined error value (58). [2] Method according to claim 1, wherein patient-specific eye information (56) is specified. [3] Method according to one of the preceding claims, wherein generic eye information (56) is specified for a human eye (14) and / or an animal eye (14). [4] Method according to one of the preceding claims, wherein a treatment device-specific error value (58) is specified. [5] Method according to one of the preceding claims, wherein a type-specific error value (58) is specified for the treatment device (10). [6] Method according to one of the preceding claims, wherein a minimum effective target depth (64) for the laser (12) is determined as a cutting depth. [7] Method according to one of the preceding claims, wherein the control data are generated for generating a lenticule (44) to be removed. [8] Method according to claim 7, wherein the control data are generated such that an anterior boundary surface (60) of the lenticule (44) is generated at the effective target depth (64). [9] Method according to one of the preceding claims, wherein the control data are generated for preparing a corneal lamella. [10] Method according to one of the preceding claims, wherein the control data are generated such that in the effective target depth (64) a refractive index in the target zone (46) is changed on the basis of the laser pulses. [11] Method according to one of the preceding claims, wherein the control data are generated in such a way that cross-linking of the cornea is carried out. [12] Method according to one of the preceding claims, wherein the effective target depth (46) is determined as a function of a three-fold standard deviation of the error value (58) and the Bowman membrane (36). [13] Method according to one of the preceding claims, wherein the effective target depth (64) is determined as a function of a nine-fold standard deviation of the error value (58) and the Bowman membrane (36). [14] A method according to any one of the preceding claims, wherein potential future treatment is taken into account. [15] Method according to one of the preceding claims, wherein a historical treatment is taken into account. [16] Method according to one of the preceding claims, wherein a warning message is issued when the determined effective target depth (64) is undershot. [17] Method for controlling a treatment device (10), the method comprising the following steps: - the method steps of a method according to one of the preceding claims, and - transmitting the provided control data to a respective ophthalmic surgical laser (12) of the treatment device (10). [18] Control device (18) which is designed to carry out a respective method according to one of the preceding claims. [19] Treatment device (10) with at least one ophthalmic surgical laser (12) for the separation of a corneal volume with predefined boundary surfaces (60, 62) of a human or animal eye (14) by means of optical disruption, in particular by means of photodisruption and / or photoablation, and at least one control device (18) according to claim 18. [20] Computer program comprising instructions which cause the treatment device (10) according to one of claims 19 to carry out a method according to one of claims 1 to 16 and / or a method according to claim 17. [21] A computer-readable medium on which a computer program according to claim 20 is stored.

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