A design method for orthokeratology lenses with optimized positioning arc area

Abstract

The present invention discloses a method for designing corneal reshaping lenses with optimized positioning arc zone, and the above-mentioned design method comprises the following steps: obtaining a positioning arc zone function; establishing an edge warping zone solution equation to obtain an edge warping zone function connected with the positioning arc zone; solving a traversal iterative function established by a first relationship between the positioning arc zone function and the corneal function; correcting the positioning arc zone function and the edge warping zone function with the result of the function solution to obtain multiple function values; selecting function values ​​that meet set conditions to determine parameters in the positioning arc zone function and the edge warping zone function to obtain an optimized design of the positioning arc zone. The corneal reshaping lenses designed according to the method of the present invention can reduce the incarceration phenomenon while obtaining a stable wearing support effect.

Description

Technical Field

[0001] The present invention relates to the technical field of ophthalmic medical devices, and in particular to a rigid gas-permeable corneal reshaping lens with optimized positioning arc area and a design method thereof. Background Art

[0002] Orthokeratology lenses use the "inverted geometry" design principle, designing the inner surface of the entire lens that contacts the cornea into several interconnected arc segments. After wearing, the special shape of the inner surface of the lens causes an unevenly distributed layer of tears to be sandwiched between the lens and the outer surface of the cornea. The fluid mechanics of the tears pulls the epithelial cells in the center of the cornea toward the mid-periphery, exerting a certain pressure on the cornea below, causing the central curvature of the cornea to flatten, and the shape of the cornea tends to the shape of the optical zone on the inner surface of the orthokeratology lens. After removing the lens, the refractive state of the human eye changes, and the imaging point of the object moves closer to the retina, thereby achieving the effect of correcting myopia.

[0003] The orthokeratology lenses in the prior art are generally divided into several areas, such as Figure 2 As shown in the figure, the part used to contact the central area of ​​the cornea is relatively flat, which is the optical zone 11, used to flatten the corneal surface, and the reversal arc zone 12 is relatively steep, which is used to stabilize the flattening effect of the optical zone and ensure a certain amount of tear storage; the positioning arc zone 13 stabilizes the lens when the contact lens is worn, and the edge warping arc zone 14 adjacent to the positioning arc zone ensures the circulation of tears around the cornea and the orthokeratology lens.

[0004] The positioning arc area is the part of the orthokeratology lens that directly contacts the cornea. Its design parameters directly affect the wearing comfort and effect. If the contact area between the positioning arc area and the cornea is too close to the center of the eye axis, the edge warping area connecting the positioning arc area is too high relative to the cornea, and the orthokeratology lens is not stable when worn. At the same time, if the contact area between the positioning arc area and the cornea is too close to the edge warping area, the orthokeratology lens is only supported by a circle around the periphery, and the orthokeratology lens cannot be stably fixed, causing incarceration. Summary of the invention

[0005] The purpose of the present application is to provide a method for designing orthokeratology lenses with optimized positioning arc zones, so as to solve the defects in the above-mentioned prior art. Specifically, the design method described in this article includes obtaining a positioning arc zone function and an edge warping zone function connected to the positioning arc zone, and then solving a traversal iterative function established by a first relationship between the positioning arc zone function and the corneal function, correcting the positioning arc zone function and the edge warping zone function with the result of the function solution, obtaining multiple function values, and finally selecting the function values ​​that meet the set conditions to determine the parameters in the positioning arc zone function and the edge warping zone function, and obtaining the optimized design of the positioning arc zone. The design method described in this article is an optimization design method for the association between the positioning arc zone and the edge warping zone, so that the tangent segment can further reduce the incarceration in improving the wearing comfort.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions.

[0007] A method for designing orthokeratology lenses with optimized positioning arc zone, characterized in that the method comprises the following steps:

[0008] Get the positioning arc area function, including the tangent line function;

[0009] Establish the edge warping area solution equation to obtain the edge warping area function connected with the positioning arc area;

[0010] Solving the ergodic iterative function established by the first relationship between the positioning arc zone function and the cornea function;

[0011] Correcting the positioning arc area function and the edge warping area function with the result of the function solution to obtain multiple function values;

[0012] The function value satisfying the set conditions is selected to determine the parameters in the positioning arc area function and the edge warping area function, and the positioning arc area optimization design is obtained.

[0013] Furthermore, the method for obtaining the tangent line function is: selecting an initial tangent point coordinate, and establishing the tangent line function with the tangent slope corresponding to the corneal function under the initial tangent point coordinate.

[0014] Furthermore, the first relationship is the integrated area between the positioning arc zone function and the corneal function.

[0015] Furthermore, the positioning arc zone function, the edge warping zone function, and the cornea function are line functions, which are line functions of the inner surface circumference under the axial section passing through the central axis of the orthokeratology lens.

[0016] Furthermore, the equation solved for the edge warping area is a circular function.

[0017] The center of the circular function is located outside the outer surface of the contact lens.

[0018] The circular plane of the circular function is parallel to an axial section passing through the central axis of the orthokeratology lens.

[0019] Furthermore, before solving the ergodic iterative function, the step iterative value of the tangent line function is substituted into the edge warping area function, or compared with a set range to determine the edge warping area design and obtain a corrected value of the tangent line function.

[0020] Furthermore, the optimal function value is such that the integrated area is minimized.

[0021] Furthermore, the coordinates of the initial tangent point are preferably 1 / 10 to 1 / 2 of the straight line segment of the positioning arc zone, starting from the position close to the optical zone.

[0022] The present invention also discloses a method for designing orthokeratology lenses with optimized positioning arc area, characterized in that the method comprises the following steps:

[0023] S1: The initial equation for constructing a straight line function that cuts off at least a portion of the positioning arc area is:

[0024] Z(x)=K(xx 0 )+z 0 Formula (1);

[0025] Where K in formula (1) is the tangent slope of the positioning arc area, x 0 is the horizontal coordinate of the tangent point of the positioning arc area, z 0 is the ordinate of the tangent point of the positioning arc area. The tangent point of the positioning arc area is P(x 0 , z 0 ), x represents the horizontal coordinate of the point on the tangent line, and Z represents the vertical coordinate of the point on the tangent line;

[0026] S2: Obtaining the tangent line function: using the above tangent line equation to obtain the direct contact segment information after contact with the cornea, and obtaining the actual positioning tangent line slope of the positioning arc area, updating the slope in the initial positioning arc area equation obtained in step S1, and obtaining the end point coordinates of the positioning arc area;

[0027] S3: obtaining the inner surface function of the edge warping area; verifying the inner surface function of the edge warping area with the end point coordinates obtained in step S2, if appropriate, proceeding to step S4; if not appropriate, reselecting the tangent point position and proceeding to step S1;

[0028] S4: solving the ergodic iterative function established by the first relationship between the positioning arc zone function and the cornea function;

[0029] S5: Obtain the optimized design of the positioning arc area with the optimal function value.

[0030] Furthermore, the step S2 further comprises:

[0031] S21: Obtain the end point coordinates of the positioning arc area;

[0032] S22: obtaining an actual contact model with the corneal function based on the length of the direct contact segment of the positioning arc area, obtaining a corrected corneal function under the corneal wearing form at the current length, and performing step-by-step iterative correction to obtain a suitable contact portion length;

[0033] To obtain the correction parameter K′, and the corrected end point coordinate value and starting point coordinate value of the positioning arc area.

[0034] Furthermore, the step S3 further comprises:

[0035] S31: Determine the inner surface function of the edge warping area, including establishing a solution equation for the edge warping area:

[0036] (x) 2 +(zb) 2 =r 2 Formula (2);

[0037] The points on the inner surface curve of the edge warping area meet the design of the circular curve; wherein a, b, and r in formula (2) are the abscissa, ordinate, and radius of the initial value center of the edge warping area, respectively, x is the abscissa of the point on the inner surface curve of the edge warping area, and z is the ordinate of the point on the inner surface curve of the edge warping area;

[0038] K=-(x 2 -a) / (z 2 -b) Formula (3);

[0039] The slope between the coordinates of the connection point between the edge warping area and the positioning arc area and the center of the circle is orthogonal to the tangent slope K of the positioning arc area; wherein, x in formula (3) 2 、z 2 are the horizontal coordinate and vertical coordinate of the connection point between the edge warping area and the positioning arc area, and a and b are the horizontal coordinate and vertical coordinate of the initial value center of the edge warping area;

[0040] S32: Obtaining a substitution value of the edge warping area solution equation, and solving to obtain the inner surface function;

[0041] S33: Substitute the end point coordinate value of the positioning arc area corrected in step S22 into the inner surface equation of the edge warping area to verify the design of the positioning arc area and obtain the corrected value of the tangent line function.

[0042] Furthermore, the step S4 further comprises:

[0043] S41: The traversal iterative function is: establishing the positioning arc area function and the corneal curve function Zcor(x) i The integral area between , where i is the i-th iteration calculation;

[0044]

[0045] Among them, x in formula (4) 0 is the horizontal coordinate of the tangent point of the positioning arc area, z 0 is the ordinate of the tangent point of the positioning arc area, x is the abscissa of the point on the inner surface curve of the edge warping area, and z is the ordinate of the point on the inner surface curve of the edge warping area;

[0046] S42: Perform iterative calculation optimization to obtain the optimal value under the minimum area S.

[0047] Furthermore, the coordinates of the tangent point are preferably 1 / 10 to 1 / 2 of the straight line segment of the positioning arc zone, measured in terms of the length range close to the optical zone.

[0048] The present invention also discloses a corneal reshaping lens with optimized positioning arc zone, comprising an optical zone, a reverse arc zone, a positioning arc zone, and an edge warping zone connected in sequence from the center to the outside, characterized in that:

[0049] The positioning arc zone includes a tangent straight line segment that is in tangent contact with the cornea, and the tangent point is located at 1 / 10 to 1 / 2 of the straight line segment, starting from the position close to the optical zone. The optimization acquisition of the tangent straight line segment executes the above method.

[0050] Furthermore, the tangent point is preferably located at 1 / 7 to 1 / 3 of the tangent line segment, starting from the position close to the optical zone.

[0051] Furthermore, the contact range between the tangent point and the cornea is located at 1 / 5 to 1 / 4 of the straight line segment, starting from the position close to the optical zone.

[0052] The present invention also discloses an electronic device, comprising:

[0053] at least one processor; and

[0054] 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 perform the above method.

[0055] The present invention also discloses a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable the computer to execute the above method.

[0056] The present invention also discloses a computer program product, comprising a computer program, wherein the computer program implements the above method when executed by a processor.

[0057] Compared with the prior art, the positive effects of the present invention are as follows:

[0058] 1. The present invention first proposes a method based on the optimization design of the positioning arc zone. In the above method, the key tangent straight line segment of the positioning arc zone of the orthokeratology lens is mainly considered to carry out the design, and an optimization design method for the relationship between the positioning arc zone and the edge warping zone is designed, so that the tangent segment can further reduce the incarceration while improving the wearing comfort;

[0059] 2. According to the method of optimizing the positioning arc area implemented by the present invention, the key parts of the tangent straight line segments are modified and iterated during the design process, so that the calculation results in the above-mentioned optimization design process method are more accurate and close to the actual value of wearing;

[0060] 3. The present invention further utilizes the associated design of the positioning arc zone to propose a design of the edge warping zone curve. By establishing a solution equation, the associated parameters of the positioning arc zone are used to solve the problem, and the tear exchange model is used to establish a basis for iterative calculation and judgment, so that a more accurate design effect can be obtained by the associated design of the positioning arc zone and the edge warping zone. When the lens has good mobility, it can provide the cornea with more sufficient oxygen to protect the health of the cornea. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 A schematic diagram showing a flow chart of a design method for a rigid gas permeable orthokeratology lens with optimized positioning arc area;

[0062] Figure 2 is a schematic structural diagram of a corneal reshaping lens according to an example of an embodiment of the present invention;

[0063] Figure 3 is a schematic flow chart of step S1 of the method for designing orthokeratology lenses according to the present invention;

[0064] Figure 4 is a schematic flow chart of step S3 of the method for designing orthokeratology lenses according to the present invention;

[0065] Figure 5 is a schematic flow chart of step S4 in the method for designing orthokeratology lenses according to the present invention;

[0066] Figure 6 It is a flowchart diagram of computer execution of the design method of orthokeratology lenses according to the present invention.

[0067] exist Figure 2 In the figure, the meanings of the reference numerals are as follows:

[0068] 1- orthokeratology lens, 2- cornea, 10- inner surface, 20- outer surface, 11- optical zone, 12- reverse arc zone, 13- positioning arc zone, 14- edge warping zone, 131- tangent straight line segment. DETAILED DESCRIPTION

[0069] Unless otherwise defined, technical or scientific terms used in the present specification and claims shall have the common meanings understood by persons having ordinary skills in the technical field to which the present invention belongs.

[0070] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0071] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0072] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be connected, detachably connected, or integrally connected; it can be mechanically connected or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0073] The orthokeratology lens 1 involved in this embodiment can be applied to the surface of the eyeball. Specifically, the orthokeratology lens 1 can be applied to the front surface of the cornea 2. The change in the shape of the cornea 2 due to wearing the orthokeratology lens can be reversible. After a period of time after the orthokeratology lens is removed, the shape of the cornea 2 will return to its initial state over time. It can be designed as a night wear type or a day wear type according to the specific situation.

[0074] In this embodiment, when the orthokeratology lens 1 is worn, a tear space can be formed between the lens and the front surface of the cornea 2 so that the tear space stores a tear layer to form a tear lens for reshaping the cornea 2. In one embodiment, the orthokeratology lens 1 can reshape the cornea 2 through the fluid force generated by the tears contained in the tear space T, thereby achieving the effect of vision correction.

[0075] The orthokeratology lens 1 involved in this embodiment may have an inner surface 10 and an outer surface 20, and the outer surface 20 is opposite to the inner surface 10. In addition, when the orthokeratology lens 1 is worn, the inner surface 10 faces the front surface of the cornea 2. The inner surface 10 may be configured to change the shape of the cornea 2. Specifically, when the orthokeratology lens 1 is worn, for example, under the action of the fluid force generated by the tears contained in the tear space and the pressure generated by the inner surface 10, the distribution of epithelial cells on the front surface of the cornea 2 may change, thereby changing the shape of the front surface of the cornea 2, and the epithelial cells on the front surface of the cornea 2 may migrate from the central part of the cornea 2 to the mid-peripheral part of the cornea 2, so that the number of epithelial cell layers in the central part of the cornea 2 is reduced, the central part is thereby thinned, and the number of epithelial cell layers in the mid-peripheral part of the cornea 2 is increased, the mid-peripheral part is thereby thickened, etc. As a result, the orthokeratology lens 1 can reshape the shape of the front surface of the cornea 2.

[0076] This embodiment relates to a corneal reshaping lens, which is a corneal reshaping lens that reshapes the shape of the cornea.

[0077] In some examples, such as Figure 2 As shown in , the orthokeratology lens 1 can be designed for multiple zones, and the more common design is three zones or four zones. In the embodiment of the present invention, the design of the orthokeratology lens with four zones is taken as an example for explanation. The inner surface 10 of the orthokeratology lens 1 can have an optical zone 11, an inversion arc zone 12, a positioning arc zone 13, and an edge warping zone 14. In some examples, the optical zone 11, the inversion arc zone 12, the positioning arc zone 13, and the edge warping zone 14 can be connected in sequence from the center to the outside. The design of the contact lens is not necessarily strictly symmetrical around the eye, that is, the design of each arc zone is non-rotationally symmetrical. Therefore, it is possible to design orthokeratology lenses with regional anisotropy according to the characteristics of the cornea.

[0078] The concept of the present invention is mainly to solve the design of the positioning arc area 13 and the edge warping area 14. The positioning arc area 13 is in direct contact with the cornea, which is a key parameter affecting the effect of the orthokeratology lens and is directly related to the wearing comfort. The associated design of the edge warping area 14 affects the channel for tear exchange, and improving the circulation and oxygen permeability of tears can better protect the health of the cornea.

[0079] According to one embodiment of the present invention, Figure 1 As shown in , a design method for a rigid gas permeable orthokeratology lens with optimized positioning arc area is proposed, which specifically includes the following steps:

[0080] S1: Get the positioning arc function;

[0081] S2: Establishing the edge warping area solution equation to obtain the edge warping area function connected with the positioning arc area;

[0082] S3: solving the ergodic iterative function established by the first relationship between the positioning arc zone function and the cornea function;

[0083] S4: correcting the positioning arc area function and the edge warping area function according to the result of the function solution to obtain a plurality of function values;

[0084] S5: Selecting function values ​​that meet set conditions to determine parameters in the positioning arc area function and the edge warping area function, and obtaining an optimal design of the positioning arc area.

[0085] According to the design of the present invention, a design method for a positioning arc zone is mainly proposed to solve the problem of being able to design orthokeratology lenses based on actual measurements of corneal functions. On the first hand, the contact coordinate position of the tangent point between the positioning arc zone and the cornea can be obtained more accurately. On the second hand, the correlation design between the positioning arc zone and the edge warping zone can be obtained to obtain the optimized corneal height of the edge warping zone, thereby achieving a stable wearing support effect while reducing the incarceration phenomenon.

[0086] According to the present invention, a design algorithm can be established for orthokeratology lenses, and the above method can be executed on the corneal periphery to match the refined measurement function of the cornea to obtain the 3D design parameters of the orthokeratology lenses.

[0087] According to the positioning arc zone function in the present invention, it at least includes a tangent function segment, the tangent of which is in direct contact with the cornea and has a set slope. The extension of the tangent function segment on the cornea is associated with determining the height between the edge warping area and the cornea.

[0088] According to the edge warping zone solution equation in the present invention, it includes selecting a setting function of the edge warping zone, constructing a solution equation for the edge warping zone, and obtaining partial parameters of the edge warping zone by locating the tangent function segment parameters of the arc zone function, and substituting them into the solution.

[0089] After the positioning arc zone function and the edge warping zone function are established according to the present invention, the positioning arc zone function and the edge warping zone function are optimized and solved. According to the design method of the present invention, the relationship between the positioning arc zone function and the corneal function is constructed, preferably the relationship between the functions of the tangent segment is used to construct the first relationship. The above relationship can also be established with the positioning arc zone function and the corneal function of the complete segment. The selected area of ​​the corresponding relationship is different, and the calculation iteration method and the judgment method are different. In other embodiments, the second relationship between the edge warping zone function and the corneal function is established at the same time, and the optimization design of the positioning arc zone is determined together with the result obtained by the simulation of the first relationship.

[0090] S1: Construct the initial equation of the positioning arc area 13, where the function expression of the tangent function segment 131 is:

[0091] Z(x)=K(xx 0 )+z 0Formula (1);

[0092] Where K in formula (1) is the tangent slope of the tangent function segment of the positioning arc area, x 0 is the horizontal coordinate of the tangent point of the positioning arc area, z 0 is the ordinate of the tangent point of the positioning arc area. The initial position of the tangent point of the positioning arc area is P(x 0 , z 0 ), x represents the horizontal coordinate of the point on the tangent line, and Z represents the vertical coordinate of the point on the tangent line; the above-mentioned tangent slope and the initial position coordinates of the tangent point can be assigned initial values ​​in the iterative operation;

[0093] S2: Obtain the end point coordinates of the tangent function segment 131, thereby obtaining the starting point coordinates of the edge warping area 14;

[0094] Obtaining the contact part between the tangent function segment 131 of the positioning arc area and the cornea for modeling: obtaining the length of the direct contact part after contacting the cornea by using the above tangent function, and obtaining the action state of the positioning arc area after contacting the cornea;

[0095] Obtain the slope of the positioning tangent after the positioning arc area actually contacts the cornea and the angle after the actual interaction, update the slope of the positioning arc area tangent function obtained in step S1, and update the initial coordinates of the end point of the positioning arc area to obtain the starting point coordinates of the edge warping area 14;

[0096] In a specific implementation of this embodiment, the contact state between the tangent function segment and the cornea is further simulated, and the tangent function slope and the tangent point coordinate value are updated to obtain an update closer to the actual wearing state;

[0097] S3: Establishing a solution equation for the edge warping area 14, obtaining a function of the edge warping area 14 connected with the positioning arc area, obtaining a design of the inner surface of the edge warping area 14, and obtaining design parameters of the edge warping area;

[0098] S4: Establish a tear exchange channel model at the rear end of the contact lens cornea. Specifically, the area of ​​the tear exchange channel formed after the positioning arc area contacts the cornea is used as the first relationship between the positioning arc area and the cornea function to perform tear exchange channel area optimization and iterative calculations; to obtain specific parameter designs for the positioning arc area and the edge warping area;

[0099] Specifically, if Figure 3 As shown in , the specific implementation of step S1 includes:

[0100] S11: Determine that the function of the positioning arc area 13 is a tangent line function: is a straight line equation, Z(x)=K(x 0 )+z 0 ;

[0101] S12: Obtain the slope of the straight line equation. First, select the initial tangent point coordinates P (x 0 , z 0 ), the coordinate reference system is the coordinate system established for the overall structure of the orthokeratology lens, and the slope of the straight line equation K = Z is obtained by evaluating the first-order derivative slope of the corneal function at the initial tangent point coordinates. cor ′(x 0 );

[0102] The corneal function is the corneal function measured without wearing orthokeratology lenses;

[0103] S13: Generate the initial tangent line function of the positioning arc area 13: Z(x)=Z cor ′(x 0 )(xx 0 )+z 0 .

[0104] In this case, since the contact lens close to the cornea is in a straight line, the straight line design can better match the shape of the cornea, that is, it can better contact and fit with the cornea. Thus, the matching with the cornea is improved, which helps to evenly disperse the pressure on the cornea and improve the safety and comfort of wearing orthokeratology lenses.

[0105] In some examples, the inner surface of the positioning arc zone 14 may include different functions in a coordinate system along the center of the eyeball outward, for example, the first part close to the inversion arc zone 12 is a curve function, and the second part connected to the first part is the part in contact with the eyeball, which is a tangent straight line function.

[0106] S14: Simulate the change in the corneal tangent slope when the initial tangent straight line function of the designed positioning arc area 13 contacts the measured corneal function. The influencing factors of the orthokeratology lens in the wearing state are changing, such as the mutual contact under the action of the eyelids, and the tear exchange channel under the tear tension in the sleeping state, so that the contact force between the positioning arc area 13 and the cornea is relatively small at this time. In actual wearing, the orthokeratology lens has the opportunity to exchange tears due to the effect of blinking during use, thereby improving the oxygen exchange rate during wearing. In actual wearing, the contact between the contact lens and the cornea will not be an ideal tangent point contact, and there will be a certain degree of linear contact, so that the initial equation needs to consider the effect on the corneal surface and make further corrections to the wearing state. At this time, the actual straight line angle in the wearing state will further shift toward the central axis, and the tangent point in contact with the cornea will become a tangent of a certain length.

[0107] The correction of the initial tangent line function in the steps of the embodiment of the present invention includes the following steps:

[0108] S141: First correction, using the first step slope to increase the correction slope as the calculation of contact deformation correction for all orthokeratology lenses;

[0109] S142: second correction, determining the third step slope based on the set length of the tangent line segment to perform correction, the change of the set length will cause the change and improvement of the corneal contact point coordinates, so further correction is required;

[0110] S143: third correction, a partial area of ​​the entire orthokeratology lens is corrected with a second step slope smaller than the first step slope, which is the area corresponding to the three o'clock and nine o'clock positions of the orthokeratology lens;

[0111] According to the method implemented by the present invention, the specific implementation of step S2 includes:

[0112] S21: Obtaining the end point coordinates of the tangent line segment 131 of the positioning arc area 13, that is, the starting point coordinates of the edge warping area 14;

[0113] The length design of the contact portion of the positioning arc area 13 involves the formation of the tear exchange channel, the formation of the wearing state after contacting the cornea, and the adjustment of the tangent point formation. After determining the slope of the contact point (tangent point) of the positioning arc area 13, an initial length is determined, and the end point coordinate value E of the positioning arc area 13 can be obtained. 2 (x 2 , z 2 ), and the coordinate value E of the starting point of the straight line 1 (x 1 , z 1 );

[0114] S22: updating the starting point coordinates of the edge warping area 14 according to the correction step of step S14; obtaining the actual contact model with the corneal function by setting the length of the contact portion of the positioning arc area 13, and obtaining the corrected corneal function under the corneal wearing form at the current length;

[0115] To obtain the correction parameter K′, the corrected end point coordinate value E of the positioning arc area 13 2 (x 2 ′,z 2 ′), and the coordinate value E of the starting point of the straight line 1 (x 1 ′,z 1 ′). The correction steps performed multiple times and interspersed in the orthokeratology lens design process can improve the accuracy of orthokeratology lens design.

[0116] According to the method implemented by the present invention, Figure 4 As shown in, the specific implementation of step S3 includes:

[0117] S31: Determine the edge warping curve design equation of the inner surface area of ​​the edge warping area 14. In one embodiment of the present invention, establish the edge warping as a circular equation with the center of the circle at the outer side. On the one hand, the circular curvature can make the edge warping and the positioning arc area have a better transition, and better connect with the process. On the other hand, the arc-shaped edge warping curvature can facilitate tear exchange and improve wearing comfort. In establishing the circular equation, it is preferred to use the inner surface of the axial section through the central axis of the orthokeratology lens as a circular surface of the design curvature curve. In other embodiments, other circular surfaces with circular design curvature curves can be selected according to the specific conditions of the cornea.

[0118] Among them, the design equation of the edge warping area 14 is:

[0119] (x) 2 +(zb) 2 =r 2 Formula (2);

[0120] The points on the inner surface curve of the edge warping zone 14 satisfy the design of the circular curve; wherein a, b, and r in formula (2) are the horizontal coordinate, vertical coordinate, and radius of the initial value center of the edge warping zone, respectively, x is the horizontal coordinate of the point on the inner surface curve of the edge warping zone, and z is the vertical coordinate of the point on the inner surface curve of the edge warping zone.

[0121] K=-(x 2 -a) / (z 2 -b) Formula (3);

[0122] The connection point (x 2 , z 2 ) and the coordinates (a, b) of the center of the circle are orthogonal to the slope of the straight line segment of the contact portion; to meet the connection between the edge warping area and the positioning arc area 13. Among them, x in formula (3) 2 、z 2 are the horizontal and vertical coordinates of the connection point between the edge warping area and the positioning arc area, and a and b are the horizontal and vertical coordinates of the initial value center of the edge warping area.

[0123] S32: Obtain the substitution value for solving the equation of the edge warping area 14, where the initial point of the edge warping area 14 is E 2 (x 2 ′,z 2 ′), the end point coordinate of the edge warping area 14 is obtained by the height value of the edge warping area, and the edge warping height at the end point of the positioning arc area 13 is obtained as h. The height of the edge warping area is the height difference between the cornea and the edge of the lens, so it can be known that the end point of the edge warping area is S 2 (x 2 ′+Δx,z 2′-h); wherein Δx can be limited by the lateral coordinate of the edge warping design, for example, the end point value of the edge warping area cannot be too large, otherwise it will affect the comfort of wearing the contact lens. In this way, the edge warping equation is solved and iteratively calculated with the set value of the edge warping height as the initial value.

[0124] Construct an equation to solve the edge warping area, substitute the above coordinate point values ​​into the solution equation, and obtain the following solution equation group:

[0125] (x 2 -a) 2 +(z 2 -b) 2 =r 2

[0126] (x 2 ′+Δx-a) 2 +(z′ 2 -hb) 2 =r 2

[0127] 2(x 2 -a)+2K(z 2 -b)=0

[0128] By solving the above three equations, the three parameters (a, b, r) of the initial center and radius of the edge warping area 14 can be obtained to obtain the initial design equation of the edge warping area 14.

[0129] S33: Solving the inner surface equation of the edge warping area 14, using the corrected end point coordinate value E in step S22 2 (x 2 ′,z 2 ') Substitute the inner surface equation of the edge warping area 14 to obtain a conclusion on whether the inner surface equation is satisfied, or solve the deviation to correct the tangent line function;

[0130] First, it can be checked whether the connection between the inner surface equation of the edge warping area and the positioning arc area 13 is appropriate;

[0131] Secondly, the design of the tangent line segment of the positioning arc area 13, as well as the length and angle of the tangent line segment, are iteratively designed through further design of the edge warping area.

[0132] According to the method implemented by the present invention, Figure 5 As shown in , the specific implementation of step S4 includes:

[0133] S41: Establishing the tear communication channel model for the first area of ​​the tangent line segment of the contact lens corneal positioning arc area

[0134] The tear communication channel model is: establishing the integral area between the function of the positioning arc area 13 and the corneal function, where i is the i-th iteration calculation;

[0135]

[0136] Among them, x in formula (4) 0 is the horizontal coordinate of the tangent point of the positioning arc area, z 0 is the ordinate of the tangent point of the positioning arc area, x is the abscissa of the point on the inner surface curve of the edge warping area, and z is the ordinate of the point on the inner surface curve of the edge warping area;

[0137] S42: Perform iterative calculation optimization to obtain the optimal value under the minimum area S.

[0138] As a further preferred embodiment of the present invention, the corneal function involved in the iterative calculation in step S41 is the corneal function obtained by actual measurement; or is the corneal function corrected by wearing simulation;

[0139] As a further preferred embodiment of the present invention, in step S41, the tear exchange channel model includes the area integral value of the first segment connected to the contact portion (in the case of a curved segment that is not a straight segment, or a partial area integral value of the reverse arc zone) as the second area, and the tear area integral value of the edge area connected to the positioning arc zone 13 as the third area. The tear exchange channel established with the areas of the above three areas is used as a circulation model for tear exchange, and the optimization of 131 of the tangent straight line segment of the positioning arc zone is jointly performed.

[0140] In one example, the function of the optical zone may be Where R bc is the vertex radius of the set orthokeratology lens, e 1 is the eccentricity.

[0141] Get the relevant parameters of the cornea, vertex area radius, eccentricity, and construct the corneal function as follows:

[0142] R cor is the vertex curvature radius of the cornea, e 2 is the eccentricity of the cornea.

[0143] According to one embodiment of the present invention, taking the above function as an example, the algorithm execution process of the optimization design of the positioning arc area 13 in the computer program medium is as follows: Figure 6 As shown in:

[0144] Acquire corneal parameters to construct a corneal function, wherein the corneal parameters are vertex curvature radius and corneal eccentricity;

[0145] Select an initial position P(x) of the tangent point of the positioning arc area 13 0 , z 0 ), find the first-order derivative of the corneal function, and set K = Z cor ′(x 0 ), construct the straight line equation of the positioning arc area: Z(x)=K(xx 0 )+z 0 Since the shape of the cornea itself is a conical section curve, and the straight matching zone is matched with the cornea in a tangent state, different straight line slopes have different tangent points with the cornea. Selecting the most appropriate slope and tangent point of the positioning arc zone 13 becomes an important parameter in designing the positioning arc zone.

[0146] Constructing a solution equation for the edge warping area, and using the tangent slope of the positioning arc area 13 to participate in the solution of the edge warping area;

[0147] Compare with the set range to determine whether the edge warping is appropriate, compare the edge warping parameters obtained in step 3 with the predetermined parameters, if appropriate, proceed to the next step 5, if not appropriate, return to step 2 to further perform the correction of the positioning arc area, adjust the tangent point of the fitting arc area in step units, and then perform the corresponding steps in sequence;

[0148] According to the integral equation, the gap area between the fitting arc area and the cornea is obtained:

[0149]

[0150] Where R is the radius of curvature of the cornea, e is the eccentricity of the cornea, and x 1 is the coordinate value of the starting point of the adaptation area, x 2 is the coordinate value of the end point of the adaptation area, K is the updated slope at this time, x 0 is the updated tangent point coordinate value at this time, z 0 For the updated tangent point coordinate value at this time, calculate and obtain the current gap area value S i ; Compare the above value currently obtained with the gap area value S of the previous cycle i-1 Compare to obtain the minimum gap area value in the iterative calculation. If not, go to step 2 to calculate and obtain S i+1 The gap area value of , if yes, then the final tangent point position output is the optimal tangent point position.

[0151] The above cycle and solution process can be used to perform a global search through computer programming to find the optimal approximate tangent point position.

[0152] As a preferred embodiment of the present invention, the coordinate value of the positioning arc zone is obtained through the overall parameters of the contact lens, and the optimal solution value obtained after solving is: the tangent point position P of the positioning arc zone is located at 1 / 4 to 1 / 2 of the positioning arc zone (i.e., close to the center of the lens), assuming that the diameter of the optical zone 11 of the lens is OZ, the width of the inversion arc zone 12 is RC, and the width of the positioning arc zone 13 is AC, then the X coordinate value of point P is: OZ / 2+RC+AC*β, wherein 1 / 10<β<1 / 2.

[0153] Furthermore, the tangent point is preferably located at 1 / 7 to 1 / 3 of the tangent line segment, starting from the position close to the optical zone.

[0154] Furthermore, the contact range between the tangent point and the cornea is located at 1 / 5 to 1 / 4 of the straight line segment, starting from the position close to the optical zone.

[0155] Since the positioning arc area is an important support for ensuring the stability of the lens, the purpose of selecting (inner 1 / 10 to 1 / 2) here is to maintain the maximum stability of the lens while avoiding being too close to the reversal arc area to cause entrapment.

[0156] The present invention uses the establishment of a tear exchange channel model as a starting point to establish a method for solving the integral area of ​​the positioning arc area. The design is mainly based on the principle of oxygen exchange in the tear space and the angle from which the bubble reduction phenomenon under the lens can be minimized.

[0157] In fact, the sagittal height of the inner surface of the orthokeratology lens gradually decreases from the center of the central zone to the contact portion of the positioning arc zone 13, and a tear space for storing tears is formed between the inner surface and the eyeball. The positioning arc zone 13 includes an area that does not contact the cornea and an area that contacts the cornea through the contact portion, and the contact portion is a linear design and a fitting surface formed by a straight line that fits with the cornea.

[0158] In addition, in the scleral lens involved in one aspect of the present disclosure, the design of the slope of the straight line makes the gap between the inner surface and the cornea as small as possible. In this case, the tear space can be reduced, so that the tear stored in the tear space can be reduced, thereby reducing the lens deviation of the orthokeratology lens and the generation of bubbles under the lens.

[0159] In addition, in one aspect of the present disclosure, the blinking effect is further considered, and the region and the landing zone are non-rotationally symmetric. Thus, a corneal reshaping lens with regional specificity can be formed.

[0160] Iterations of different precisions and global searches are performed in the upper eyelid area and lower eyelid area where tear exchange is easy, as well as in the left and right quadrants where tear exchange is not easy to occur, so that the orthokeratology lenses can achieve better personalized wearing effects.

[0161] In addition, in the design method involved in another aspect of the present disclosure, optionally, the corneal function is obtained using optical coherence tomography technology. Thus, the corneal parameters of the eyeball can be accurately measured, but the corneal function modeled or the corneal function improved and corrected after combining the performance parameters of the user's wearing habits can also be used in the design scheme of the present invention.

[0162] In some examples, the width of the positioning arc area 13 may be 0.75 mm to 2 mm. For example, the width of the positioning arc area 13 may be 0.75 mm, 0.9 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm or 2 mm.

[0163] The present invention further discloses a corneal reshaping lens, and the optimization method of the positioning arc area thereof is obtained by executing the above method. In some examples, the slope may be 0.2 to 1.2.

[0164] The present invention also provides a storage medium storing a computer program executable by a processor, which, when executed on the processor, causes the processor to execute any of the steps of the above-mentioned general product traceability method for the industry. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0165] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0166] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0167] In the several embodiments provided by the present invention, it should be understood that the disclosed system can be implemented in other ways. For example, the system embodiments described above are only schematic, such as the division of the modules, which is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, indirect coupling or communication connection of systems or modules, which can be electrical or other forms.

[0168] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0169] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of software functional modules.

[0170] If the integrated module is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory, including several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0171] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without having to pay creative labor. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art based on the contents disclosed by the present invention without departing from the scope and spirit of the present invention are within the scope of the present invention.

Claims

1. A design method for orthokeratology lenses with optimized positioning arc area. It is characterized in that The method comprises the following steps: Get the positioning arc area function, including the tangent line function; Establishing an edge warping zone solution equation to obtain an edge warping zone function connected with the positioning arc zone; the edge warping zone solution equation includes selecting a setting function of the edge warping zone, constructing an edge warping zone solution equation, obtaining partial parameters of the edge warping zone by using the tangent function segment parameters of the positioning arc zone function, and substituting them into the solution; Solving the ergodic iterative function established by the first relationship between the positioning arc zone function and the cornea function; the first relationship is the integral area between the positioning arc zone function and the cornea function; Correcting the positioning arc area function and the edge warping area function with the result of the function solution to obtain multiple function values; The function value satisfying the set conditions is selected to determine the parameters in the positioning arc area function and the edge warping area function, and the positioning arc area optimization design is obtained.

2. The method for designing orthokeratology lenses with optimized positioning arc area according to claim 1, It is characterized in that The method for obtaining the tangent line function is: selecting an initial tangent point coordinate, and establishing the tangent line function with the tangent slope corresponding to the corneal function under the initial tangent point coordinate.

3. The method for designing orthokeratology lenses with optimized positioning arc area as claimed in claim 2, It is characterized in that The positioning arc zone function, the edge warping zone function, and the cornea function are line functions, which are line functions of the inner surface circumference under the axial section passing through the central axis of the orthokeratology lens.

4. The method for designing orthokeratology lenses with optimized positioning arc area according to claim 1, It is characterized in that The equation to be solved for the edge warping area is a circular function; The center of the circular function is located outside the outer surface of the contact lens; The circular plane of the circular function is parallel to an axial section passing through the central axis of the orthokeratology lens.

5. The method for designing orthokeratology lenses with optimized positioning arc zone as claimed in claim 1, It is characterized in that Before solving the traversal iterative function, the step iterative value of the tangent line function is substituted into the edge warping area function, or compared with a set range to determine the edge warping area design and obtain a corrected value of the tangent line function.

6. The method for designing orthokeratology lenses with optimized positioning arc zones as claimed in claim 2, It is characterized in that The coordinates of the initial tangent point are 1 / 10 to 1 / 2 of the straight line segment of the positioning arc zone, starting from the position close to the optical zone.

7. A design method for orthokeratology lenses with optimized positioning arc area. It is characterized in that The method comprises the following steps: S1: The initial equation for constructing a straight line function that cuts off at least a portion of the positioning arc area is: Z(x)=K(xx 0 )+z 0 Formula (1); Where K in formula (1) is the tangent slope of the positioning arc area, x 0 is the horizontal coordinate of the tangent point of the positioning arc area, z 0 is the ordinate of the tangent point of the positioning arc area. The tangent point of the positioning arc area is P(x 0 , z 0 ), x represents the horizontal coordinate of the point on the tangent line, and Z represents the vertical coordinate of the point on the tangent line; S2: Obtaining the tangent line function: using the above tangent line equation to obtain the direct contact segment information after contact with the cornea, and obtaining the actual positioning tangent line slope of the positioning arc area, updating the slope in the initial positioning arc area equation obtained in step S1, and obtaining the end point coordinates of the positioning arc area; S3: obtaining the inner surface function of the edge warping area; verifying the inner surface function of the edge warping area with the end point coordinates obtained in step S2, if appropriate, proceeding to step S4; if not appropriate, reselecting the tangent point position and proceeding to step S1; S4: solving the ergodic iterative function established by the first relationship between the positioning arc zone function and the cornea function; S5: Obtain the optimal design of the positioning arc area with the optimal function value; The step S2 further comprises: S21: Obtain the end point coordinates of the positioning arc area; S22: obtaining an actual contact model with the corneal function based on the length of the direct contact segment of the positioning arc area, obtaining a corrected corneal function under the corneal wearing form at the current length, and performing step-by-step iterative correction to obtain a suitable contact portion length; To obtain the correction parameter K′, and the corrected end point coordinate value and starting point coordinate value of the positioning arc area; The step S3 further comprises: S31: Determine the inner surface function of the edge warping area, including establishing a solution equation for the edge warping area: (x) 2 +(zb) 2 =r 2 Formula (2); The points on the inner surface curve of the edge warping area meet the design of the circular curve; wherein a, b, and r in formula (2) are the abscissa, ordinate, and radius of the initial value center of the edge warping area, respectively, x is the abscissa of the point on the inner surface curve of the edge warping area, and z is the ordinate of the point on the inner surface curve of the edge warping area; K=-(x 2 -a) / (z 2 -b) Formula (3); The slope between the coordinates of the connection point between the edge warping area and the positioning arc area and the center of the circle is orthogonal to the tangent slope K of the positioning arc area; wherein, x in formula (3) 2 、z 2 are the horizontal coordinate and vertical coordinate of the connection point between the edge warping area and the positioning arc area, and a and b are the horizontal coordinate and vertical coordinate of the initial value center of the edge warping area; S32: Obtaining a substitution value of the edge warping area solution equation, and solving to obtain the inner surface function; S33: Substituting the end point coordinate value of the positioning arc area corrected in step S22 into the inner surface equation of the edge warping area to check the design of the positioning arc area and obtain the corrected value of the tangent line function; The step S4 further comprises: S41: The traversal iterative function is: establishing the positioning arc area function and the corneal curve function Zcor(x) i The integral area between , where i is the i-th iteration calculation; Among them, x in formula (4) 0 is the horizontal coordinate of the tangent point of the positioning arc area, z 0 is the ordinate of the tangent point of the positioning arc area, x is the abscissa of the point on the inner surface curve of the edge warping area, and z is the ordinate of the point on the inner surface curve of the edge warping area; S42: Perform iterative calculation optimization to obtain the optimal value under the minimum area S.

8. A corneal reshaping lens with optimized positioning arc zone, comprising an optical zone (11), a reverse arc zone (12), a positioning arc zone (13), and an edge warping zone (14), which are connected in sequence from the center to the outside. It is characterized in that The positioning arc zone (13) includes a tangent straight line segment that is in tangent contact with the cornea, and the tangent point is located at 1 / 10 to 1 / 2 of the straight line segment, starting from the position close to the optical zone. The optimization acquisition of the tangent straight line segment is performed by the method described in any one of claims 1-7.

9. The orthokeratology lens with optimized positioning arc area as claimed in claim 8, It is characterized in that The tangent point is located at 1 / 7 to 1 / 3 of the tangent line segment, starting from the position close to the optical zone.

10. The orthokeratology lens with optimized positioning arc zone as claimed in claim 8, It is characterized in that The contact range between the tangent point and the cornea is located at 1 / 5 to 1 / 4 of the straight line segment, starting from the position close to the optical zone.

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