Customizable Defocus Corneal Reshaping Lens Design Method, Device, Equipment and Storage Medium Based on TFT Tear Film Design

Abstract

The present application discloses a design method, device, equipment and storage medium of a customizable defocus corneal reshaping lens based on TFT tear film design, which relates to the technical field of corneal reshaping lenses. The method includes: obtaining corneal shape parameters and target defocus parameters of a target object; constructing a corneal function model through a preset aspheric function according to the corneal shape parameters and the target defocus parameters; determining the construction point coordinates corresponding to each arc segment according to the corneal function model, and performing superposition adjustment on the construction point coordinates through a preset tear film layer thickness; solving the curvature radius of each arc segment according to the adjusted coordinates of each arc segment to obtain the design parameters of the corneal reshaping lens for the target object. Since the present application can adjust by superimposing the tear film layer thickness on the construction point coordinates of each arc segment, thereby realizing independent regulation of the sagittal height of each arc segment, which is beneficial to eliminating the arc segment parameter linkage effect in the traditional design, making the curvature adjustment of each arc segment not interfere with each other, and improving the flexibility of the corneal reshaping lens design.

Description

Technical Field

[0001] The present application relates to the technical field of orthokeratology lenses, and in particular to a design method, device, equipment and storage medium for orthokeratology lenses with customizable defocus based on TFT tear film design. Background Art

[0002] Orthokeratology lenses are optical correction devices that alter corneal morphology through inverse geometric design. Their inner surface utilizes a multi-segment structure, leveraging the tear layer's fluid pressure between the lens and cornea to temporarily flatten the central corneal curvature to correct myopia. This simultaneously creates myopic defocus in the periphery and inhibits axial length growth. Traditional design methods construct lens curves based on continuous aspheric equations, reshaping the cornea by adjusting the curvature radius of each segment. These methods rely on a static distribution model of tear layer thickness to control the fluid dynamics.

[0003] However, there is a problem of sag linkage in the arc segment design of traditional orthokeratology lenses: the parameters of each arc segment are highly coupled, and adjusting the curvature of a single arc segment will cause the overall sag linkage to change, thereby limiting the precise control of local defocus and affecting the flexibility of orthokeratology lens design. Summary of the Invention

[0004] The main purpose of this application is to provide a method, device, equipment and storage medium for designing corneal refractive therapy lenses with customizable defocus based on TFT tear film design, aiming to solve the technical problem of low flexibility in corneal refractive therapy lens design due to the existence of vector height linkage when designing the arc segment of corneal refractive therapy lenses in the existing method.

[0005] To achieve the above objectives, the present application proposes a method for designing orthokeratology lenses with customizable defocus based on TFT tear film design, the method comprising:

[0006] Obtaining corneal morphological parameters and target defocus parameters of the target object;

[0007] Constructing a corneal function model by presetting an aspheric function according to the corneal morphological parameters and the target defocus parameters;

[0008] Determine the coordinates of the construction points corresponding to each arc segment according to the corneal function model, and adjust the coordinates of the construction points by superimposing according to the preset tear layer thickness;

[0009] The curvature radius of each arc segment is solved according to the adjusted coordinates of each arc segment to obtain the orthokeratology lens design parameters of the target object.

[0010] In one embodiment, the step of constructing a corneal function model by using a preset aspheric function according to the corneal morphological parameters and the target defocus parameters includes:

[0011] Initialize the corneal function model based on the even aspheric formula, where the corneal function model includes the aspheric coefficient and polynomial coefficients to be solved;

[0012] Establish a constraint equation set according to the corneal morphological parameters and the target defocus parameters;

[0013] Solve the constraint equation set, and assign values to the aspheric coefficient and the polynomial coefficients in the corneal function model according to the solution results.

[0014] In one embodiment, the corneal morphological parameters include: corneal curvature, and the target defocus parameters include: the correspondence between the preset defocus position range and the target defocus amount. The expression of the corneal function model is:

[0015]

[0016] In the formula, R is the corneal curvature radius, k is the aspheric coefficient, and A4, A6, and A8 are the polynomial coefficients.

[0017] In one embodiment, the constraint equation set is:

[0018]

[0019] In the formula, is the aspheric coefficient calculation formula containing the parameter , is the base curve curvature, T is the target defocus amount, endshift is the gap amount corresponding to the base curve position, is the gap amount corresponding to the position within the preset defocus position range, is the gap amount corresponding to the position within the preset defocus position range.

[0020] In one embodiment, the step of determining the construction point coordinates corresponding to each arc segment according to the corneal function model includes:

[0021] Determine the base curve arc length, reverse curve arc length, positioning arc arc length, and peripheral arc arc length according to the corneal morphological parameters;

[0022] Based on the corneal function model, determine the construction point coordinates corresponding to the reverse curve, positioning arc, and peripheral arc respectively according to the base curve arc length, reverse curve arc length, positioning arc arc length, and peripheral arc arc length.

[0023] In one embodiment, the construction point coordinates include: starting point coordinates, control point coordinates, and ending point coordinates. The step of superimposing and adjusting the construction point coordinates by a preset tear film thickness includes:

[0024] Obtain tear film thickness design information, where the tear film thickness design information includes: the preset tear film thickness corresponding to the starting point, control point, and ending point respectively;

[0025] Superimpose and adjust the ordinate values of the starting point coordinates, the control point coordinates, and the ending point coordinates respectively according to each of the preset tear film thicknesses to obtain the adjusted starting point coordinates, adjusted control point coordinates, and adjusted ending point coordinates.

[0026] In one embodiment, the step of solving the curvature radius of each arc segment according to the adjusted arc segment coordinates and obtaining the orthokeratology lens design parameters of the target object includes:

[0027] Construct a system of linear equations including the adjusted starting point coordinates, adjusted control point coordinates, and adjusted ending point coordinates in a three-points-on-a-circle manner;

[0028] Solve the system of linear equations corresponding to the reverse curve, the positioning curve, and the peripheral curve respectively to obtain the arc segment expressions corresponding to the reverse curve, the positioning curve, and the peripheral curve respectively;

[0029] Determine the reverse curve curvature radius, the positioning curve curvature radius, and the peripheral curve curvature radius respectively according to each of the arc segment expressions, and combine the base curve curvature to obtain the orthokeratology lens design parameters of the target object, where the base curve curvature is determined in advance according to the corneal curvature in the corneal shape parameters.

[0030] In addition, to achieve the above object, the present application also proposes an orthokeratology lens design device, where the device includes:

[0031] A parameter collection module, configured to obtain the corneal shape parameters and target defocus parameters of a target object;

[0032] A model construction module, configured to construct a corneal function model through a preset aspheric function according to the corneal shape parameters and target defocus parameters;

[0033] A control design module, configured to determine the construction point coordinates corresponding to each arc segment according to the corneal function model, and superimpose and adjust the construction point coordinates by a preset tear film thickness;

[0034] A parameter output module, configured to solve the curvature radius of each arc segment according to the adjusted arc segment coordinates and obtain the orthokeratology lens design parameters of the target object.

[0035] In addition, to achieve the above object, the present application also provides a corneal reshaping lens design device, which includes: a memory, a processor, and a corneal reshaping lens design program stored on the memory and executable on the processor. The computer program is configured to implement the steps of the corneal reshaping lens design method with customizable defocus based on TFT tear film as described above.

[0036] In addition, to achieve the above object, the present application also provides a storage medium, which is a computer-readable storage medium. A corneal reshaping lens design program is stored on the storage medium. When the corneal reshaping lens design program is executed by a processor, it implements the steps of the corneal reshaping lens design method with customizable defocus based on TFT tear film as described above.

[0037] The present application discloses a corneal reshaping lens design method with customizable defocus based on TFT tear film. The method includes obtaining corneal shape parameters and target defocus parameters of a target object; constructing a corneal function model according to the corneal shape parameters and the target defocus parameters through a preset aspheric function; determining the coordinates of construction points corresponding to each arc segment according to the corneal function model, and adjusting the coordinates of the construction points by superimposing a preset tear film thickness; and solving the curvature radius of each arc segment according to the adjusted coordinates of each arc segment to obtain the corneal reshaping lens design parameters of the target object. Since the present application can adjust by superimposing the tear film thickness on the coordinates of construction points in each arc segment, independent control of the sagittal height of each arc segment can be achieved, which is beneficial to eliminating the linkage effect of arc segment parameters in traditional designs, making the curvature adjustment of each arc segment not interfere with each other, and thus improving the flexibility of corneal reshaping lens design. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0039] To more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the accompanying drawings required for describing the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 It is a schematic flowchart of the first embodiment of the corneal reshaping lens design method with customizable defocus based on TFT tear film of the present application;

[0041] Figure 2 It is a schematic flowchart of the second embodiment of the corneal reshaping lens design method with customizable defocus based on TFT tear film of the present application;

[0042] Figure 3This is a schematic diagram of adjusting the arc segment curvature radius;

[0043] Figure 4 This is a schematic diagram of the effect of orthokeratology lens preparation;

[0044] Figure 5 This is a structural diagram of the first embodiment of the orthokeratology lens design device of the present application;

[0045] Figure 6 This is a schematic diagram of the structure of the corneal refractive therapy lens design equipment for this application. DETAILED DESCRIPTION

[0046] It should be understood that the specific embodiments described herein are merely used to explain the technical solutions of the present application and are not intended to limit the present application.

[0047] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0048] The main solution of this embodiment is: obtaining the corneal morphological parameters and target defocus parameters of the target object; constructing a corneal function model through a preset aspheric function based on the corneal morphological parameters and target defocus parameters; determining the construction point coordinates corresponding to each arc segment based on the corneal function model, and superimposing and adjusting the construction point coordinates through a preset tear layer thickness; solving the curvature radius of each arc segment based on the adjusted arc segment coordinates to obtain the corneal refractive therapy lens design parameters of the target object.

[0049] Most existing orthokeratology lenses are divided into four arc zones: the central base curve (BC) zone (also known as the optical zone), followed by the reverse curve (RC), alignment curve (AC), and peripheral curve (PC) zones. The fundamental requirement for orthokeratology lens design is that lens sag equals corneal sag, where lens sag is equal to the sum of the sags of each segment. In a common vertically spaced stylus (VST) design, each segment is interconnected and together form the inner surface of the orthokeratology lens. The radius of curvature and eccentricity are design inputs. By manipulating these two parameters, the sag and shape of each segment can be altered. Therefore, for a given cornea, adjusting one segment often affects the overall lens sag, necessitating coordinated adjustments to the other segments to ensure consistency between the lens's total sag and the corneal sag, which in turn limits the flexibility of orthokeratology lens design.

[0050] In the solution of the present application, the TFT (Tear Film Treatment) tear film design method is adopted to optimize the inner surface parameters of the orthokeratology lens by presetting an ideal tear film storage form, ensuring a high degree of fit between the lens and the cornea. Specifically, based on a pre-constructed corneal function model, the ideal tear film shape under the lens is superimposed, and for each arc segment, the starting point, middle control point, and end point of the lens are obtained from three points on the model cornea and the corresponding tear film thickness. By solving the arc through the method of three points on the same circle, the shape of each arc segment on the inner surface of the orthokeratology lens can be obtained. The curvature radius of each arc segment is the output after shape construction, and each arc segment does not involve sagittal height linkage and can be adjusted independently, thereby improving the flexibility of the orthokeratology lens design.

[0051] It should be noted that the execution subject of the method in this embodiment can be a computing service device with data processing, network communication, and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc. In this embodiment, the orthokeratology lens design device (hereinafter referred to as the "design device") is taken as an example to illustrate this embodiment and the following embodiments.

[0052] Based on this, the embodiment of the present application provides a method for designing an orthokeratology lens with customizable defocus based on TFT tear film design, referring to Figure 1 , Figure 1 is a schematic flowchart of the first embodiment of the method for designing an orthokeratology lens with customizable defocus based on TFT tear film design in the present application. In this embodiment, the method includes: steps S10 to S40:

[0053] Step S10: Obtain the corneal shape parameters and target defocus parameters of the target object.

[0054] It should be noted that the target object can be a user who needs to wear an orthokeratology lens, such as a myopic patient, etc. The fitter can perform a pre-fitting operation on the user and obtain the parameters related to the shape and structure of the target object's cornea through corneal topography or OCT scanning, such as corneal curvature, corneal diameter, eccentricity, corneal vertex height, etc.

[0055] It should also be noted that the target defocus parameter can be the myopia control effect that the fitter hopes to achieve after orthokeratology shaping according to the aforementioned parameters related to the shape and structure of the cornea, for example: the target defocus amount expected to be achieved at the preset defocus position. The defocus amount refers to the distance between the position where the light is focused in front of or behind the retina and the retina, expressed in diopters (D). The size and distribution of the defocus amount directly affect the optical effect and myopia control effect of the orthokeratology lens.

[0056] Step S20: Construct a corneal function model according to the corneal shape parameters and target defocus parameters through a preset aspheric function.

[0057] It should be noted that when constructing the corneal function model, the optical zone can adopt an aspherical design. Thus, without changing the diameter of the optical zone, by adopting a gradient defocus customized design, the entrance pupil defocus amount can be fully increased, the myopia prevention and control effect can be effectively improved, and at the same time, the impact on visual quality can be reduced. Therefore, to specifically illustrate the construction process of the corneal function model, step S20 includes steps S201 to S203:

[0058] Step S201: Initialize the corneal function model based on the even aspherical formula. The corneal function model includes the aspherical coefficient to be solved and the polynomial coefficients.

[0059] It should be understood that the above preset aspherical function can be an even aspherical formula, and the even aspherical formula is as follows:

[0060]

[0061] In the formula, z is the height in the optical axis direction, c is the curvature, r is the radial coordinate, representing the distance from the optical axis to the surface, k is the conic coefficient, i.e., the aspherical coefficient, used to describe the basic shape of the aspherical surface. The first term is the general quadric surface equation, the second term is the quadratic paraboloid equation, and the subsequent terms are high-order terms.

[0062] Define the corneal function model according to the even aspherical formula, and the corneal function model can be expressed as follows:

[0063]

[0064] In the formula, R is the corneal curvature radius, which is the reciprocal of the corneal curvature, k is the aspherical coefficient, and A4, A6, and A8 are polynomial coefficients.

[0065] It should be understood that through high-order aspherical curvature adjustment, the aspherical design can form a smaller central flattened area without changing the base curve diameter and generate a reverse curve with double depth. This design not only improves the corneal reshaping efficiency but also increases the peripheral defocus area and defocus amount, strengthening the myopia control effect.

[0066] Step S202: Establish a constraint equation set according to the corneal shape parameters and the target defocus parameters.

[0067] It should be understood that a constraint equation set for solving the unknown aspherical coefficient k and polynomial coefficients A4, A6, and A8 in the aforementioned corneal function model can be constructed according to the correspondence between the corneal curvature and the preset defocus position range and the target defocus amount. The equation set can be expressed as follows:

[0068]

[0069] In the formula, contains the parameter The calculation formula of the aspheric coefficient is: is the base arc curvature, T is the target defocus amount, and endshift is the base arc The gap corresponding to the position, For the preset defocus position range The gap amount corresponding to the position, For the preset defocus position range The gap corresponding to the position. And .

[0070] It should be noted that the above parameters The calculation formula of the aspheric coefficient It can be expressed as:

[0071]

[0072] Where Fa is the derivative of the aspheric quadratic term, and the rate of change of the derivative slope (second-order derivative) can be used to analyze the aspheric curvature distribution to obtain the k value of the aspheric coefficient; 337.5 is the constant used to calculate the corneal curvature.

[0073] The above base curve curvature For a given value, the base curve curvature can be = Corneal curvature - target reduction - Jessen factor. The Jessen factor is the overpressure of the lens, generally 0.75D. The target reduction is predetermined by the fitter based on the fitting information (myopia degree) of the target subject.

[0074] It should also be noted that the gap refers to the thickness of the tear layer formed between the orthokeratology lens and the cornea. It is used to construct the ideal tear mold shape, and an initial value is usually set with reference to the shape of the normal cornea. The fitter can adjust the gap appropriately based on the tear shape of the initial lens.

[0075] The defocus range and target defocus amount can also be pre-set by the fitter based on the user's measured diopter. The fitter can freely combine different defocus positions and defocus amounts, for example, setting the defocus range to 3.0-6.2mm and the target defocus amount to 2-15D. Generally, users with a diopter exceeding 4D use a larger defocus position and defocus amount; users with a diopter within 4D use a smaller defocus position and smaller defocus amount.

[0076] Step S203: Solve the constraint equations, and assign values to the aspheric coefficients and the polynomial coefficients in the corneal function model according to the solution results.

[0077] It should be noted that when the base arc curvature K and the target defocus amount T are known, the base arc diameter , and are respectively substituted into the above constraint equations for simultaneous solution, so as to solve the aspherical coefficient k and the polynomial coefficients A4, A6, and A8, and further obtain the values, and then obtain the complete expression of the corneal function model . Among them, the corresponding width of the base arc diameter can be obtained by the fitter according to the corneal topographic map corresponding to the cornea of the target object in advance.

[0078] Step S30: Determine the coordinates of the construction points corresponding to each arc segment according to the corneal function model, and perform superposition adjustment on the coordinates of the construction points through a preset tear film thickness.

[0079] It should be noted that the corneal shape parameters of the target object may also include the arc lengths of each arc segment pre-divided by the fitter according to the cornea of the target object. Then, according to the arc lengths of each arc segment, the abscissa values of the construction points corresponding to each arc segment can be obtained. Substitute the abscissa values of each construction point into the aforementioned corneal function model, and the corresponding ordinate values can be obtained, and then the coordinates of each construction point can be obtained.

[0080] It should be understood that in order to obtain the function expression of each arc segment, it is necessary to determine at least the coordinates of three points that make up the arc segment. Usually, the starting point, midpoint, and end point corresponding to each arc segment can be selected as the construction points of the arc segment.

[0081] It should also be noted that since the core of the corneal reshaping lens depends on the shape of the tear film under the lens after wearing the lens, on the basis of this corneal function model, the thickness of the ideal tear film needs to be superimposed to determine the shape of each arc segment on the inner surface of the corneal reshaping lens. The preset tear film thickness can be the tear film thickness pre-designed by the fitter based on the corneal curvature and target defocus amount of the target object.

[0082] In a specific implementation, after obtaining the coordinates of the construction points corresponding to each arc segment according to the arc length of each arc segment, the tear film thickness corresponding to each arc segment can be superimposed on the coordinates of the construction points of each arc segment to obtain the adjusted coordinates of the construction points. The adjusted coordinates of the construction points can be used to solve the shape of the arc segment on the inner surface of the finally determined corneal reshaping lens.

[0083] Step S40: Solve the radius of curvature of each arc segment according to the adjusted coordinates of each arc segment to obtain the design parameters of the corneal reshaping lens for the target object.

[0084] It should be understood that since the construction points of each arc segment can include the starting point, midpoint, and end point, the radius of the circle to which each arc segment belongs can be solved by the three-point co-circle method, that is, the radius of curvature of each arc segment is obtained, and then it is output as the design parameters of the corneal reshaping lens for the target object.

[0085] In this embodiment, the corneal shape parameters and the target defocus parameters of the target object are obtained; according to the corneal shape parameters and the target defocus parameters, a corneal function model is constructed through a preset aspherical function; according to the corneal function model, the coordinates of the construction points corresponding to each arc segment are determined, and the coordinates of the construction points are superimposed and adjusted through a preset tear film thickness; the curvature radii of each arc segment are solved according to the adjusted coordinates of each arc segment, and the design parameters of the orthokeratology lens for the target object are obtained. Since this embodiment can adjust by superimposing the coordinates of the construction points of each arc segment with the tear film thickness, the independent regulation of the sagittal height of each arc segment can be realized, which is beneficial to eliminating the linkage effect of the arc segment parameters in the traditional design, making the curvature adjustment of each arc segment not interfere with each other, and further improving the flexibility of the orthokeratology lens design.

[0086] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar content as the above-mentioned embodiment 1 can be referred to the above introduction and will not be repeated hereinafter. On this basis, please refer to Figure 2 , Figure 2 which is a schematic flowchart of the second embodiment of the design method of the customizable defocus orthokeratology lens based on the TFT tear film design of the present application.

[0087] In this embodiment, in order to specifically illustrate how to obtain the function expressions of other arcs (reverse curve, alignment curve, and peripheral curve), step S30 specifically includes: steps S301 to S304:

[0088] Step S301: Determine the base curve arc length, reverse curve arc length, alignment curve arc length, and peripheral curve arc length according to the corneal shape parameters.

[0089] Step S302: Based on the corneal function model, determine the coordinates of the construction points corresponding to the reverse curve, alignment curve, and peripheral curve respectively according to the base curve arc length, reverse curve arc length, alignment curve arc length, and peripheral curve arc length.

[0090] It should be understood that since the corneal shape parameters of the target object may also include the arc lengths of each arc segment pre-divided by the fitter according to the target object's cornea: BC arc length, RC arc length, AC arc length, and PC arc length. Then, exemplarily, taking the position of the center point of the BC arc length as the origin of the x-axis coordinate, the x-axis coordinate values of the corresponding construction points can be obtained in turn by combining the RC arc length, AC arc length, and PC arc length.

[0091] It should also be noted that since the construction points include the starting point, midpoint (control point), and ending point, for a certain arc segment, the coordinates of the corresponding construction points can be , , . Among them, the y-axis coordinate values of each construction point can be calculated by substituting the x-axis coordinate values determined above into the corneal function model.

[0092] Step S303: obtaining tear layer thickness design information, wherein the tear layer thickness design information includes: preset tear layer thicknesses corresponding to the starting point, the control point, and the end point respectively.

[0093] It should be understood that the fitter can design the tear layer thickness corresponding to the starting point, control point, and end point of each arc segment based on the target patient's myopia and industry tear layer setting rules. For different corneal shapes and refractive powers, the same tear layer thickness can be superimposed on each arc segment. This can be reflected in the reverse arc area to stabilize the tear storage space capacity and improve the central positioning performance of the orthokeratology lens in the adaptation arc area.

[0094] Step S304: superimposing and adjusting the vertical coordinate values of the starting point coordinate, the control point coordinate, and the ending point coordinate according to the preset tear layer thicknesses to obtain adjusted starting point coordinates, adjusted control point coordinates, and adjusted ending point coordinates.

[0095] It is understandable that for a certain arc segment, the preset tear layer thickness corresponding to the starting point, the control point and the end point can be 、 、 Therefore, the adjusted starting point coordinates, control point coordinates, and end point coordinates can be 、 、( ).

[0096] In addition, in order to specifically explain how to obtain different shapes of arc output by adjusting the thickness of the tear layer, you can refer to Figure 3 The adjustment process of the curvature radius is explained. Figure 3 Schematic diagram of adjusting the arc segment curvature radius.

[0097] exist Figure 3 In the figure, the green line represents the curvature of the lens, the red line represents the model cornea, and the blue line represents the model volume adjusted based on the tear layer thickness.

[0098] Depend on Figure 3 It can be seen that the arc shape is constructed by superimposing the tear layer thickness on the model cornea determined by the corneal model function. The sagittal height of each arc segment is fixed by the starting point and the ending point, and the arc curvature radius is controlled by the control point, so that the arc output of different shapes can be obtained by adjusting the tear layer thickness.

[0099] Further, in order to specifically illustrate the process of solving the arc segment curvature radius, step S40 specifically includes: steps S401 to S403:

[0100] Step S401: Construct a system of linear equations that includes the adjusted starting point coordinates, the adjusted control point coordinates, and the adjusted ending point coordinates in a three - point - on - a - circle manner.

[0101] Step S402: Solve the systems of linear equations corresponding to the reverse arc, the positioning arc, and the peripheral arc respectively to obtain the arc segment expressions corresponding to the reverse arc, the positioning arc, and the peripheral arc respectively.

[0102] It should be noted that since the circular formula is , for a certain arc segment, the arc to be solved satisfies the system of linear equations:

[0103]

[0104]

[0105]

[0106] Solve this system of linear equations. It is easy to solve for the constants A, B, and C corresponding to this circular formula. Then the circular formula can be converted into the standard form of a circle, and further the radius of the circle where this arc segment is located, that is, the curvature radius of this arc segment, can be obtained.

[0107] In specific implementation, apply the above three - point - on - a - circle method to solve the reverse arc, the positioning arc, and the peripheral arc respectively, and then the standard form of the circle and the corresponding curvature radius can be obtained respectively.

[0108] Step S403: Determine the reverse arc curvature radius, the positioning arc curvature radius, and the peripheral arc curvature radius respectively according to each of the arc segment expressions, and combine with the base arc curvature to obtain the corneal reshaping lens design parameters of the target object.

[0109] It should be noted that since the curvature radius of the base arc can be directly calculated from the corneal curvature, that is, the curvature radii of the reverse arc, the positioning arc, and the peripheral arc solved by the above three - point - on - a - circle method. Then when finally outputting the corneal reshaping lens design parameters, for the convenience of subsequent preparation of the corneal reshaping lens, the corneal reshaping lens design parameters can include the aforementioned base arc curvature radius, reverse arc curvature radius, positioning arc curvature radius, and peripheral arc curvature radius, and can also include the thickness of the tear layer superimposed on the construction points in each arc segment.

[0110] Furthermore, based on these corneal reshaping lens design parameters, prepare the corneal reshaping lens, and the prepared corneal reshaping lens can be as Figure 4 shown, Figure 4 which is a schematic diagram of the preparation effect of the corneal reshaping lens.

[0111] From Figure 4It can be seen that the defocus type corneal reshaping lens has better squeeze film force, which can pull the lens towards the cornea to achieve better shaping. Moreover, compared with the "flat pan" defocus state of the spherical design, the aspherical corneal reshaping lens can form a continuous and complete peripheral defocus distribution in the shape of a "pointed bottom pan". This defocus state places the entire eye in a stronger myopic defocus environment, more effectively inhibiting the growth of the eye axis.

[0112] In this embodiment, by determining the arc lengths of each arc segment according to the corneal shape parameters and substituting them into the corneal function model to obtain the coordinates of the starting point, control point, and ending point of each arc segment, then adjusting the coordinates by superimposing the corresponding preset tear film thickness on the ordinate value, and finally solving for the reverse curve radius of curvature, positioning curve radius of curvature, and peripheral curve radius of curvature in a three-point co-circular manner based on the adjusted coordinates, and then outputting them together with the base curve radius of curvature as the corneal reshaping lens design parameters of the target object. Since the radius of curvature of each arc segment in this embodiment is the output quantity after shape construction and there is no sagittal height linkage for each arc segment, they can be adjusted independently. For different corneal curvatures and refractive powers, the same tear film thickness can also be superimposed on each arc segment. This can make the volume of the tear storage space more stable in the reverse curve area and improve the central positioning performance of the corneal reshaping lens in the fitting arc area, thereby obtaining a more ideal shaping effect and further enhancing the flexibility of the corneal reshaping lens design.

[0113] It should be noted that the above examples are only for understanding the present application and do not constitute a limitation to the corneal reshaping lens design method of customizable defocus based on TFT tear film of the present application. Any simple transformation in more forms based on this technical concept is within the protection scope of the present application.

[0114] In addition, the present application also provides a corneal reshaping lens design device. Refer to Figure 5 , Figure 5 which is the structural block diagram of the first embodiment of the corneal reshaping lens design device of the present application; as Figure 5 shown, the device includes:

[0115] A parameter collection module 501, configured to obtain the corneal shape parameters and target defocus parameters of the target object;

[0116] A model construction module 502, configured to construct a corneal function model according to the corneal shape parameters and target defocus parameters through a preset aspherical function;

[0117] A control design module 503, configured to determine the construction point coordinates corresponding to each arc segment according to the corneal function model and perform superposition adjustment on the construction point coordinates through a preset tear film thickness;

[0118] A parameter output module 504, configured to solve for the radius of curvature of each arc segment according to the adjusted coordinates of each arc segment to obtain the corneal reshaping lens design parameters of the target object.

[0119] Further, the model construction module 502 is further configured to initialize a corneal function model based on an even aspheric formula, where the corneal function model includes aspheric coefficients to be solved and polynomial coefficients; establish a constraint equation set according to the corneal shape parameters and the target defocus parameters; solve the constraint equation set, and assign values to the aspheric coefficients and the polynomial coefficients in the corneal function model according to the solution results.

[0120] Among them, the corneal shape parameters include corneal curvature, and the target defocus parameters include the correspondence between a preset defocus position range and a target defocus amount. The expression of the corneal function model is:

[0121]

[0122] In the formula, R is the corneal curvature radius, k is the aspheric coefficient, and A4, A6, and A8 are the polynomial coefficients.

[0123] The constraint equation set is:

[0124]

[0125] In the formula, is an aspheric coefficient calculation formula including parameters , is the base curve curvature, T is the target defocus amount, endshift is the gap amount corresponding to the base curve position, is the gap amount corresponding to the position within the preset defocus position range, is the gap amount corresponding to the position within the preset defocus position range.

[0126] Further, the control design module 503 is further configured to determine the base curve arc length, the reverse curve arc length, the positioning arc length, and the peripheral arc length according to the corneal shape parameters; based on the corneal function model, determine the construction point coordinates corresponding to the reverse curve, the positioning arc, and the peripheral arc respectively according to the base curve arc length, the reverse curve arc length, the positioning arc length, and the peripheral arc length.

[0127] Among them, the construction point coordinates include starting point coordinates, control point coordinates, and ending point coordinates.

[0128] Further, the control design module 503 is further configured to obtain tear film thickness design information, where the tear film thickness design information includes: preset tear film thicknesses corresponding to the starting point, the control point, and the ending point respectively; and adjust the ordinate values of the starting point coordinates, the control point coordinates, and the ending point coordinates by superimposing according to the respective preset tear film thicknesses, so as to obtain the adjusted starting point coordinates, the adjusted control point coordinates, and the adjusted ending point coordinates.

[0129] Further, the parameter output module 504 is further configured to construct a system of linear equations including the adjusted starting point coordinates, the adjusted control point coordinates, and the adjusted ending point coordinates in a three-points-on-a-circle manner; solve the systems of linear equations corresponding to the reverse curve, the positioning curve, and the peripheral curve respectively to obtain arc segment expressions corresponding to the reverse curve, the positioning curve, and the peripheral curve respectively; determine the curvature radii of the reverse curve, the positioning curve, and the peripheral curve respectively according to the respective arc segment expressions, and combine with the base curve curvature to obtain the corneal orthokeratology lens design parameters of the target object, where the base curve curvature is determined in advance according to the corneal curvature in the corneal shape parameters.

[0130] This embodiment can adjust by constructing point coordinates and superimposing the tear film thickness in sub-arc segments, so as to realize independent regulation of the sag heights of each arc segment, which is beneficial to eliminating the arc segment parameter linkage effect in the traditional design, making the curvature adjustment of each arc segment not interfere with each other, and further improving the flexibility of the corneal orthokeratology lens design.

[0131] In addition, the present application further provides a corneal orthokeratology lens design device, where the corneal orthokeratology lens design device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the corneal orthokeratology lens design method with customizable defocus based on TFT tear film design in the first embodiment above.

[0132] Next, refer to Figure 6 , Figure 6 which is a schematic structural diagram of the corneal orthokeratology lens design device of the present application. The corneal orthokeratology lens design device in the embodiments of the present application may include, but is not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistant), PADs (Portable Application Description: tablet computers), PMPs (Portable Media Player: portable multimedia players), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 6The shown orthokeratology lens design device is merely an example and should not impose any limitations on the functions and usage scope of the embodiments of this application.

[0133] As Figure 6 shown, the orthokeratology lens design device may include a processing device 1001 (such as a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM: Read Only Memory) 1002 or the program loaded from the storage device 1003 into the random access memory (RAM: Random Access Memory) 1004. In the RAM 1004, various programs and data required for the operation of the orthokeratology lens design device are also stored. The processing device 1001, the ROM 1002, and the RAM 1004 are connected to each other through a bus 1005. The input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the orthokeratology lens design device to communicate with other devices wirelessly or wiredly to exchange data. Although the orthokeratology lens design device with various systems is shown in the figure, it should be understood that it is not required to implement or have all the shown systems. More or fewer systems can be alternatively implemented or had.

[0134] In addition, this application also provides a computer-readable storage medium having computer-readable program instructions (i.e., computer programs) stored thereon, and the computer-readable program instructions are used to execute the orthokeratology lens design method with customizable defocus based on the TFT tear film in the above embodiments.

[0135] The computer-readable storage medium provided by this application can be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or components, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash memory, optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this embodiment, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, device, or component. The program code contained on the computer-readable storage medium can be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0136] It should be noted that in this document, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or system comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of additional elements in the process, method, article or system comprising that element.

[0137] The serial numbers of the above embodiments of the present invention are for description only and do not represent the superiority or inferiority of the embodiments. Moreover, they are only some embodiments of this application and do not limit the patent scope of this application. Any equivalent structural transformation made under the technical concept of this application using the content of the specification and drawings of this application, or any direct / indirect application in other related technical fields, is included in the patent protection scope of this application.

Claims

1. A design method for orthokeratology lenses with customizable defocus based on TFT tear film design, characterized in that, The method includes: Obtaining corneal shape parameters and target defocus parameters of a target object; Constructing a corneal function model according to the corneal shape parameters and the target defocus parameters through a preset aspheric function; Determining the construction point coordinates corresponding to each arc segment according to the corneal function model, and performing superposition adjustment on the construction point coordinates through a preset tear film thickness; Solving the curvature radius of each arc segment according to the adjusted arc segment coordinates to obtain the orthokeratology lens design parameters of the target object; Among them, the step of constructing a corneal function model according to the corneal shape parameters and the target defocus parameters through a preset aspheric function includes: Initializing the corneal function model based on an even aspheric formula, where the corneal function model includes aspheric coefficients and polynomial coefficients to be solved; Establishing a constraint equation set according to the corneal shape parameters and the target defocus parameters; Solving the constraint equation set, and assigning values to the aspheric coefficients and the polynomial coefficients in the corneal function model according to the solution results.

2. The method according to claim 1, wherein The corneal shape parameters include corneal curvature, and the target defocus parameters include the corresponding relationship between a preset defocus position range and a target defocus amount. The expression of the corneal function model is: In the formula, R is the corneal curvature radius, k is the aspheric coefficient, and A4, A6, and A8 are the polynomial coefficients.

3. The method according to claim 2, wherein The constraint equation set is: In the formula, is the calculation formula for the aspheric coefficient including , where is the curvature of the base arc, T is the target defocus amount, and endshift is the gap amount corresponding to the position of the base arc . is the gap amount corresponding to the position located within the preset defocus position range , is the gap amount corresponding to the position located within the preset defocus position range .​​ 4. The method according to claim 1, wherein The step of determining the construction point coordinates corresponding to each arc segment according to the corneal function model includes: Determining the base curve arc length, reverse curve arc length, alignment arc length, and peripheral arc length according to the corneal shape parameters; Based on the corneal function model, determining the construction point coordinates corresponding to the reverse curve, the alignment arc, and the peripheral arc respectively according to the base curve arc length, the reverse curve arc length, the alignment arc length, and the peripheral arc length.

5. The method according to claim 4, wherein The construction point coordinates include starting point coordinates, control point coordinates, and ending point coordinates. The step of performing superposition adjustment on the construction point coordinates through a preset tear film thickness includes: Obtaining tear film thickness design information, where the tear film thickness design information includes the preset tear film thickness corresponding to the starting point, the control point, and the ending point respectively; Performing superposition adjustment on the ordinate values of the starting point coordinates, the control point coordinates, and the ending point coordinates respectively according to each preset tear film thickness to obtain the adjusted starting point coordinates, the adjusted control point coordinates, and the adjusted ending point coordinates.

6. The method according to claim 5, wherein The step of solving the curvature radius of each arc segment according to the adjusted arc segment coordinates to obtain the orthokeratology lens design parameters of the target object includes: Constructing a linear equation set including the adjusted starting point coordinates, the adjusted control point coordinates, and the adjusted ending point coordinates in a three-points-on-a-circle manner; Respectively solving the linear equation sets corresponding to the reverse curve, the alignment arc, and the peripheral arc to obtain the arc segment expressions corresponding to the reverse curve, the alignment arc, and the peripheral arc respectively; Determine the reverse arc curvature radius, the positioning arc curvature radius, and the peripheral arc curvature radius respectively according to each of the arc segment expressions, and obtain the orthokeratology lens design parameters of the target object in combination with the base arc curvature, where the base arc curvature is determined in advance according to the corneal curvature in the corneal shape parameters.

7. A corneal reshaping lens design device, characterized in that, The device includes: A parameter collection module for obtaining the corneal shape parameters and the target defocus parameters of the target object; A model construction module for constructing a corneal function model through a preset aspheric function according to the corneal shape parameters and the target defocus parameters; A control design module for determining the construction point coordinates corresponding to each arc segment according to the corneal function model and performing superposition adjustment on the construction point coordinates through a preset tear film thickness; A parameter output module for solving the curvature radius of each arc segment according to the adjusted arc segment coordinates and obtaining the orthokeratology lens design parameters of the target object; The model construction module is further configured to initialize the corneal function model based on the even-order aspheric formula, where the corneal function model includes aspheric coefficients and polynomial coefficients to be solved; establish a constraint equation set according to the corneal shape parameters and the target defocus parameters; solve the constraint equation set, and assign values to the aspheric coefficients and the polynomial coefficients in the corneal function model according to the solution results.

8. A corneal reshaping lens design device, characterized in that, The device includes: a memory, a processor, and an orthokeratology lens design program stored on the memory and executable on the processor, where the orthokeratology lens design program is configured to implement the steps of the orthokeratology lens design method with customizable defocus based on TFT tear film design according to any one of claims 1 to 6.

9. A computer storage medium, characterized in that, An orthokeratology lens design program is stored on the computer storage medium, and when the orthokeratology lens design program is executed by the processor, the steps of the orthokeratology lens design method with customizable defocus based on TFT tear film design according to any one of claims 1 to 6 are implemented.

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