An automatic multi-arc segment circle arc fitting method and device applied to a corneal contact lens

Abstract

The application relates to the technical field of data analysis, in particular to an automatic multi-arc segment circular arc fitting method and device applied to a corneal contact lens. The method and device comprise the following steps: automatically segmenting multi-arc segments by using a multi-arc segment automatic segmentation algorithm; fitting a central arc segment first by using experience knowledge, and automatically segmenting first arc segment information by using data points and fitting errors of the first arc segment; iteratively searching different arc segments in sequence, and fitting the searched different arc segments, so that automatic segmentation and curvature radius measurement of different arc segments of the corneal contact lens are completed. The application fits the central arc segment first by using experience knowledge, automatically segments the first arc segment information by using data points and fitting errors of the first arc segment, iteratively searches different arc segments in sequence, and finally completes the automatic segmentation and the curvature radius measurement of different arc segments of the corneal contact lens, so that the measurement error caused by too small arc segment fitting is reduced.

Description

Technical Field

[0001] This invention relates to the field of data analysis technology, and more specifically, to an automatic multi-segment circular arc fitting method and apparatus for use with corneal contact lenses. Background Technology

[0002] Contact lenses (also known as corneal contact lenses) can be divided into two main categories based on their manufacturing materials: rigid gas permeable (RGP) contact lenses and soft contact lenses. They are widely used due to their advantages such as small size, light weight, and wide field of vision. Compared to eyeglasses, contact lenses come into direct contact with the cornea, making material safety and parameter reliability paramount. Morphologically, the cornea is not a sphere. The central area, approximately 3mm-4mm in diameter, known as the corneal cap, is considered spherical. Measuring parameters such as the radius of curvature typically involves measuring the power of this corneal cap. The cornea becomes flatter towards the periphery. Therefore, if the lens is designed with only one curvature, conforming solely to the central corneal curvature, a mismatch may occur at the periphery or limbus, potentially resulting in excessive tightness or pressure marks. Thus, a second, third, or even more curvatures are designed from the central area outwards.

[0003] The purpose of designing these arcs is to achieve a morphological match with the peripheral cornea, ensuring a proper fit. This improves comfort and also ensures proper tear circulation. It's important to note that at the intersections of the arcs, there's a raised area called the junction, a byproduct of the multi-arc design. If worn in the eye, it can put pressure on the cornea, causing a foreign body sensation. Therefore, manufacturers often treat the junction specially during lens design, such as grinding or polishing, to reduce discomfort during wear.

[0004] Measuring the geometric parameters of corneal contact lenses is crucial for ensuring their effectiveness and visual safety. This includes checking whether the radius of curvature of different segments meets the design values, typically using corneal topographers, profilometers, or OCT-based contact lens measurement devices. However, because the radius of curvature varies between different segments of the contact lens, and the range of the segments decreases towards the outer edges, measurement errors are significant, and it is difficult to distinguish between different segments.

[0005] In summary, the existing technology has the following technical problems:

[0006] 1. The parameters measured by profilometers and other measuring equipment are mostly compared with the design values ​​and the obtained profiles, and the curvature radius distribution of arc segments in different ranges is obtained by partitioning, which is difficult to automatically segment.

[0007] 2. In a corneal contact lens parameter measurement system based on SD - OCT, it is proposed to use polynomial curve fitting for arc segment differentiation measurement, but most data points deviate from the fitting curve in the fitting effect. Summary of the Invention

[0008] An embodiment of the present invention provides an automatic multi - arc circular arc fitting method and device for corneal contact lenses to at least solve the technical problem of poor fitting effect of existing multi - arc circular arc fitting.

[0009] According to an embodiment of the present invention, an automatic multi - arc circular arc fitting method for corneal contact lenses is provided, including the following steps:

[0010] S101: Automatically segment multi - arcs using a multi - segment arc automatic segmentation algorithm;

[0011] S102: First, fit the central arc segment using empirical knowledge, and automatically segment the first arc segment information using the fitting error between the data points and the first arc segment;

[0012] S103: Iteratively search for different arc segments in sequence, and fit the searched different arc segments to complete the automatic segmentation of different arc segments of the corneal contact lens and the measurement of the radius of curvature.

[0013] Furthermore, in step S101, the left and right arc segments are combined for circular fitting calculation, and the center range is constrained in the circular arc fitting algorithm, and the center parameters of different arc segments are constrained on the same straight line.

[0014] Furthermore, step S101 includes:

[0015] (1) According to the conventional design parameters, perform circular arc fitting on the area close to the symmetry axis with a diameter range of 5 mm to obtain the first - segment parameters , calculate the error of all sample points N according to the circular parameters:

[0016] (2) Calculate the fitting error threshold, the average error and standard deviation of points in the diameter range of 6 mm:

[0017] (3) According to the fitting error threshold find the point where the upper - segment arc ends and the point where the lower - segment arc starts, and perform circular arc fitting of the second segment with a step size of step1;

[0018] (4) According to the circular arc fitting parameters of the second segment arc, repeat step (2) for the remaining points. If the obtained value of meanE is large, it means that the step size of step1 is too large and the circular arc fitting error is large. Then update the search step size to step1 / 2 and reread step (2) until meanE < tol1, repeat step (3), update the end point of the second segment arc and start calculating the next segment arc;

[0019] (5) Repeat steps (2)-(4) until all data points are calculated.

[0020] Further, the range of the next arc points is: (-endPoint1-step, endPoint1-Btol) and (endPoint1 + Btol, endpoint1 + step), where Btol is the spacing point added to remove the connection between the first arc and the second arc.

[0021] Further, step S103 specifically includes:

[0022] (1) According to the conventional design parameters, perform circular arc fitting on the area near the symmetry axis with a diameter range of 5 mm to obtain the parameters of the first segment. , calculate the error of all sample points N according to the circle parameters:

[0023]

[0024] (2) Calculate the fitting error threshold, the average error and standard deviation of the points with a diameter range of 6 mm:

[0025]

[0026]

[0027]

[0028] (3) According to the fitting error threshold Find the end point of the upper arc and the start point of the lower arc, and perform circular arc fitting on the second segment with a step size of step1:

[0029]

[0030] (4) According to the circular arc fitting parameters of the second segment, repeat step (2) for the remaining points. If the obtained value of meanE is large, it means that the step size of step1 is too large and the circular arc fitting error is large. Then update the search step size with step1 / 2 and re-read step (2) until meanE < tol1, repeat step (3), update the end point of the second segment and start calculating the next segment;

[0031] (5) Repeat steps (2)-(4) until all data points are calculated.

[0032] Further, use the circle fitting algorithm to fit the short arc segments after segmentation.

[0033] Further, the circle fitting algorithm specifically includes:

[0034]

[0035] in Given an arc of n data points, let's consider one of them. These are the center position and the radius of the arc, respectively.

[0036] Given a circular arc, points A, B, and C are the leftmost, middle, and rightmost points of the arc, respectively. Initial circle fitting parameters are obtained by using these three points for initial arc fitting.

[0037]

[0038]

[0039] Solving the system of linear equations to obtain the initial solution of the circle center parameters The initial radius parameter is:

[0040]

[0041] Using an initial solution at the center of the circle combined with an iterative solution using a least-squares optimization algorithm, the objective function is: Minimum circle parameter ;

[0042] To eliminate the influence of data noise, the error at each point after fitting is calculated:

[0043]

[0044] If the point error meets the requirements, then remove these data points and re-optimize the circle parameters using the least squares algorithm:

[0045] .

[0046] According to another embodiment of the present invention, an automatic multi-segment circular arc fitting device for corneal contact lenses is provided, comprising:

[0047] Automatic segmentation unit, used to automatically segment multiple arc segments using a multi-arc automatic segmentation algorithm;

[0048] The fitting unit is used to first fit the central arc segment using empirical knowledge, and then automatically segment the first arc segment information using the fitting error between the data points and the first arc segment.

[0049] The iterative unit is used to iteratively search for different arc segments and fit the searched arc segments to complete the automatic segmentation of different arc segments of the corneal contact lens and the measurement of the radius of curvature.

[0050] A storage medium storing a program file capable of implementing any of the above-mentioned automatic multi-segment circular arc fitting methods for corneal contact lenses.

[0051] A processor for running a program, wherein the program executes any of the above-mentioned automatic multi-segment circular arc fitting methods for corneal contact lenses.

[0052] The automatic multi-segment circular arc fitting method and device for corneal contact lenses in this embodiment of the invention first fits the central arc segment using empirical knowledge, and then automatically segments the first arc segment information using the fitting error between the data points and the first arc segment. The method iteratively searches for different arc segments in turn, and finally completes the automatic segmentation of different arc segments of the corneal contact lens and the measurement of the radius of curvature, thereby reducing the measurement error caused by fitting arc segments that are too small. Attached Figure Description

[0053] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0054] Figure 1 This is a flowchart of the automatic multi-segment circular arc fitting method of the present invention applied to corneal contact lenses;

[0055] Figure 2 This is a flowchart of the circular arc fitting algorithm in this invention;

[0056] Figure 3 This is a flowchart of the automatic segmentation algorithm for multi-segment arcs in this invention;

[0057] Figure 4 This is a block diagram of the automatic multi-segment circular arc fitting device of the present invention applied to corneal contact lenses. Detailed Implementation

[0058] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0059] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0060] Example 1

[0061] According to an embodiment of the present invention, an automatic multi-segment circular arc fitting method for corneal contact lenses is provided, see [link to relevant documentation]. Figure 1 This includes the following steps:

[0062] S101: Automatic segmentation of multiple arc segments using a multi-segment arc automatic segmentation algorithm;

[0063] S102: First, fit the central arc segment using empirical knowledge, and then automatically segment the first arc segment information using the fitting error between the data points and the first arc segment.

[0064] S103: Iterate through different arc segments sequentially, and fit the different arc segments found to complete the automatic segmentation of different arc segments of the corneal contact lens and the measurement of the radius of curvature.

[0065] The automatic multi-segment circular arc fitting method for corneal contact lenses in this embodiment of the invention first fits the central arc segment using empirical knowledge, and then automatically segments the first arc segment information using the fitting error between the data points and the first arc segment. The method iteratively searches for different arc segments in turn, and finally completes the automatic segmentation of different arc segments of the corneal contact lens and the measurement of the radius of curvature, thereby reducing the measurement error caused by fitting arc segments that are too small.

[0066] Specifically, contact lenses are commonly used for vision correction in teenagers and for controlling keratoconus, and they come into direct contact with the cornea. Since the cornea is not a perfect sphere, and the periphery is flatter than the center, contact lenses are often designed as several segments of arcs with different radii of curvature to better fit the cornea and improve wearing comfort. For contact lenses and other samples composed of multiple arcs, where the diameter of each arc is small and there are no clear dividing points, this invention proposes an automatic arc segmentation algorithm for such contact lenses. Using empirical knowledge, the algorithm first fits the central arc segment, and then automatically segments the first arc segment using the fitting error between the data points and the first arc segment. This process iteratively searches for different arc segments, ultimately completing the automatic segmentation of different arc segments of the contact lens and the measurement of the radius of curvature.

[0067] This invention proposes an automated multi-segment circular arc fitting method for corneal contact lenses. Since the measured multi-segment samples are mostly axially symmetric, that is, the left and right arc segments are symmetrical, the measurement error caused by fitting the left and right arc segments together can be reduced by performing circular arc fitting on both the left and right arc segments together.

[0068] 1. Circular arc fitting algorithm

[0069] See Figure 2 Since the data points are limited, the range of arc segments they contain is small, and the data points contain noisy information, a circle fitting algorithm for short arc segments is proposed.

[0070] (1)

[0071] in Given an arc of n data points, let's consider one of them. These represent the center position and the radius of the arc, respectively.

[0072] For example, consider a circular arc. Points A, B, and C are the leftmost, middle, and rightmost points of the same arc. Initial arc fitting parameters are obtained by using these three points:

[0073]

[0074] (2)

[0075] Solving the system of linear equations to obtain the initial solution of the circle center parameters The initial radius parameter is:

[0076] (3)

[0077] Using an initial solution at the center of the circle combined with an iterative solution using a least-squares optimization algorithm, the objective function is: Minimum circle parameter .

[0078] To eliminate the influence of data noise, the error at each point after fitting is calculated:

[0079] (4)

[0080] If the point error satisfies the formula, then remove these data points and re-optimize the circle parameters using the least squares algorithm.

[0081] (5)

[0082] 2. Automatic segmentation algorithm for multi-segment arcs

[0083] See Figure 3 , since most of the samples are composed of symmetric arc segments, that is, the left and right circular arcs are different regions of the same arc, so the left and right arc segments can be merged for circle fitting calculation, and the center range constraint is performed on the circle fitting algorithm, and the center parameters of different arc segments are constrained on the same straight line.

[0084] The specific process is as follows:

[0085] (1) According to the conventional design parameters, perform circular arc fitting on the area within a 5-mm diameter range close to the symmetry axis to obtain the parameters of the first segment , calculate the error of all sample points N according to the circle parameters:

[0086] (6)

[0087] (2) Calculate the fitting error threshold, the average error and standard deviation of the points within a 6-mm diameter range:

[0088] (7)

[0089] (8)

[0090] (9)

[0091] (3) According to the fitting error threshold Find the point where the upper segment of the arc ends and the point where the lower segment of the arc starts, and perform circular arc fitting on the second segment with a step size of step1:

[0092] (10)

[0093] The range of points for the next segment of the arc is: (-endPoint1-step, endPoint1-Btol) and (endPoint1+Btol, endpoint1+step), where Btol is the interval point added to remove the connection between the first segment of the arc and the second segment of the arc.

[0094] (4) According to the circular arc fitting parameters of the second segment of the arc, repeat step (2) for the remaining points (removing the determined upper segment of the arc area (-endpoint1, endpoint1)). If the value of meanE obtained is large, it means that the step size of step1 is too large and the circular arc fitting error is large. Then update the search step size with step1 / 2 and reread step (2) until meanE < tol1, repeat step (3), update the end point of the second segment of the arc and start calculating the next segment of the arc.

[0095] (5) Repeat steps (2)-(4) until all data points are calculated.

[0096] The key points and areas to be protected in this invention are:

[0097] This invention proposes an automatic arc segmentation algorithm for corneal contact lens measurement. Based on the extracted two-dimensional contour of the corneal contact lens, arc fitting is performed to automatically identify different sections of the corneal contact lens and calculate the corresponding radius of curvature.

[0098] Compared with existing technologies, the present invention can automatically perform arc segmentation without requiring detailed design information, and can also perform measurements even when design data is missing.

[0099] Example 2

[0100] According to another embodiment of the present invention, an automatic multi-segment circular arc fitting device for corneal contact lenses is provided, see [link to documentation]. Figure 4 ,include:

[0101] Automatic segmentation unit 201 is used to automatically segment multiple arc segments using a multi-segment arc automatic segmentation algorithm;

[0102] The fitting unit 202 is used to first fit the central arc segment using empirical knowledge, and then automatically segment the first arc segment information using the fitting error between the data points and the first arc segment.

[0103] The iteration unit 203 is used to iteratively search for different arc segments and fit the different arc segments found to complete the automatic segmentation of different arc segments of the corneal contact lens and the measurement of the radius of curvature.

[0104] The automatic multi-segment circular arc fitting device for corneal contact lenses in this embodiment of the invention first fits the central arc segment using empirical knowledge, and then automatically segments the first arc segment information using the fitting error between the data points and the first arc segment. Iteratively searches for different arc segments in turn, and finally completes the automatic segmentation of different arc segments of the corneal contact lens and the measurement of the radius of curvature, thereby reducing the measurement error caused by fitting arc segments that are too small.

[0105] Specifically, contact lenses are commonly used for vision correction in teenagers and for controlling keratoconus, and they come into direct contact with the cornea. Since the cornea is not a perfect sphere, and the periphery is flatter than the center, contact lenses are often designed as several segments of arcs with different radii of curvature to better fit the cornea and improve wearing comfort. For contact lenses and other samples composed of multiple arcs, where the diameter of each arc is small and there are no clear dividing points, this invention proposes an automatic arc segmentation algorithm for such contact lenses. Using empirical knowledge, the algorithm first fits the central arc segment, and then automatically segments the first arc segment using the fitting error between the data points and the first arc segment. This process iteratively searches for different arc segments, ultimately completing the automatic segmentation of different arc segments of the contact lens and the measurement of the radius of curvature.

[0106] This invention proposes an automatic multi-segment circular arc fitting device for corneal contact lenses. Since the measured multi-segment samples are mostly axially symmetric, that is, the left and right arc segments are symmetrical, the measurement error caused by fitting the left and right arc segments together can be reduced by performing circular arc fitting on both the left and right arc segments together.

[0107] 1. Circular arc fitting algorithm

[0108] See Figure 2 Since the data points are limited, the range of arc segments they contain is small, and the data points contain noisy information, a circle fitting algorithm for short arc segments is proposed.

[0109] (1)

[0110] in Given an arc of n data points, let's consider one of them. These represent the center position and the radius of the arc, respectively.

[0111] For example, consider a circular arc. Points A, B, and C are the leftmost, middle, and rightmost points of the same arc. Initial arc fitting parameters are obtained by using these three points:

[0112]

[0113] (2)

[0114] Solving the system of linear equations to obtain the initial solution of the circle center parameters The initial radius parameter is:

[0115] (3)

[0116] Using an initial solution at the center of the circle combined with an iterative solution using a least-squares optimization algorithm, the objective function is: Minimum circle parameter .

[0117] To eliminate the influence of data noise, the error at each point after fitting is calculated:

[0118] (4)

[0119] If the point error satisfies the formula, then remove these data points and re-optimize the circle parameters using the least squares algorithm.

[0120] (5)

[0121] 2. Automatic segmentation algorithm for multi-segment arcs

[0122] See Figure 3 , since most of the samples are composed of symmetric arc segments, that is, the left and right circular arcs are different regions of the same arc segment, so the left and right arc segments can be combined for circular fitting calculation, and the center range constraint is carried out on the circular arc fitting algorithm, and the center parameters of different arc segments are constrained on the same straight line.

[0123] The specific process is as follows:

[0124] (1) According to the conventional design parameters, circular arc fitting is carried out on the area within the diameter range of 5 mm close to the symmetry axis to obtain the parameters of the first segment , calculate the error of all sample points N according to the circle parameters:

[0125] (6)

[0126] (2) Calculate the fitting error threshold, the average error and standard deviation of the points within the diameter range of 6 mm:

[0127] (7)

[0128] (8)

[0129] (9)

[0130] (3) According to the fitting error threshold Find the point where the upper segment arc ends and the point where the lower segment arc starts, and perform circular arc fitting of the second segment with a step size of step1:

[0131] (10)

[0132] The point range of the next segment arc is: (-endPoint1-step, endPoint1-Btol) and (endPoint1+Btol, endpoint1+step), where Btol is the interval point added to remove the connection between the first segment arc and the second segment arc.

[0133] (4) According to the circular arc fitting parameters of the second segment arc, repeat step (2) for the remaining points (removing the determined upper segment arc region (-endpoint1, endpoint1)). If the obtained value of meanE is large, it means that the step size of step1 is too large and the circular arc fitting error is large. Then update the search step size with step1 / 2 and reread step (2) until meanE<tol1, repeat step (3), update the end point of the second segment arc and start the calculation of the next segment arc.

[0134] (5) Repeat steps (2)-(4) until all data points are calculated.

[0135] The key points and areas to be protected in this invention are:

[0136] This invention proposes an automatic arc segmentation algorithm for corneal contact lens measurement. Based on the extracted two-dimensional contour of the corneal contact lens, arc fitting is performed to automatically identify different sections of the corneal contact lens and calculate the corresponding radius of curvature.

[0137] Compared with existing technologies, the present invention can automatically perform arc segmentation without requiring detailed design information, and can also perform measurements even when design data is missing.

[0138] Example 3

[0139] A storage medium storing a program file capable of implementing any of the above-mentioned automatic multi-segment circular arc fitting methods for corneal contact lenses.

[0140] Example 4

[0141] A processor for running a program, wherein the program executes any of the above-mentioned automatic multi-segment circular arc fitting methods for corneal contact lenses.

[0142] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0143] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0144] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The system embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of units or modules may be electrical or other forms.

[0145] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0146] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0147] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, 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. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0148] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An automated multi-segment circular arc fitting method for corneal contact lenses, characterized in that, It includes the following steps: S101: Automatically segment the multi-arc segments using the multi-segment arc automatic segmentation algorithm; S102: First, fit the central arc segment using empirical knowledge, and automatically segment the information of the first arc segment based on the fitting error between the data points and the first arc segment; S103: Iteratively search for different arc segments in sequence, and fit the different arc segments found to complete the automatic segmentation of different arc segments of the contact lens and the measurement of the radius of curvature; where: In step S101, the left and right arc segments are combined for circular fitting calculation, and the range of the center of the circle is constrained in the circular arc fitting algorithm, and the center parameters of different arc segments are constrained on the same straight line; The range of the next arc points is: (-endPoint1-step, endPoint1-Btol) and (endPoint1+Btol, endpoint1+step), where Btol is the interval point added to remove the connection between the first arc segment and the second arc segment; Step S101 specifically includes: (1) Based on conventional design parameters, perform circular arc fitting on the region with a diameter range of 5mm near the axis of symmetry to obtain the parameters of the first segment. Calculate the error for all sample points N based on the circle parameters: (2) Calculate the fitting error threshold, the average error and standard deviation of the points with a diameter range of 6mm: (3) Based on the fitting error threshold Find the end point of the upper arc and the beginning point of the lower arc, and fit the second arc with a step size of step1: (4) According to the circular arc fitting parameters of the second arc segment, repeat step (2) for the remaining points. If the obtained value of meanE is large, it means that the step size of step1 is too large and the circular arc fitting error is large. Then update the search step size with step1 / 2 and reread step (2) until meanE<tol1, repeat step (3), update the end point of the second arc segment and start the calculation of the next arc segment; (5) Repeat steps (2)-(4) until all data points are calculated.

2. The automatic multi-segment circular arc fitting method for corneal contact lenses according to claim 1, characterized in that, Use the circular fitting algorithm to fit the segmented short arc segments.

3. The automatic multi-segment circular arc fitting method for corneal contact lenses according to claim 2, characterized in that, The circular fitting algorithm specifically includes: in Given an arc of n data points, let's consider one of them. These represent the center position and the radius of the arc, respectively. For a circular arc, points A, B, and C are the leftmost, middle, and rightmost points of the same circular arc. Initial circular arc fitting is performed through these three points to obtain the initial circular fitting parameters: The R-factor elimination operation is performed on the fitted parameters of the circle to obtain: Solving the system of linear equations to obtain the initial solution of the circle center parameters The initial radius parameter is: Use the initial solution of the center of the circle combined with the least squares optimization algorithm to iteratively solve the objective function: Minimum circle parameter ; To exclude the influence of data noise, calculate the error of each point after fitting: ； If the point error meets the requirements, remove these data points and re-optimize the circle parameters using the least squares algorithm: 。 4. An automatic multi-segment circular arc fitting device for corneal contact lenses, utilizing the automatic multi-segment circular arc fitting method for corneal contact lenses as described in claim 1, characterized in that, It includes: An automatic segmentation unit for automatically segmenting multi-arc segments using the multi-segment arc automatic segmentation algorithm; [[ID=十八]]A fitting unit for first fitting the central arc segment using empirical knowledge and automatically segmenting the information of the first arc segment based on the fitting error between the data points and the first arc segment; An iterative unit for iteratively searching for different arc segments in sequence and fitting the different arc segments found to complete the automatic segmentation of different arc segments of the contact lens and the measurement of the radius of curvature.

5. A storage medium, characterized in that, The storage medium stores a program file that can implement the automatic multi-segment arc circular fitting method for contact lenses described in any one of claims 1 to 3.

6. A processor, characterized in that, The processor is used to run the program, and when the program runs, it executes the automatic multi-segment arc circular fitting method for contact lenses described in any one of claims 1 to 3.

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