Layered measurement method for polarization parameters of cornea anterior surface structure and related device

Abstract

The embodiment of the invention discloses a layered measurement method for polarization parameters of a cornea anterior surface structure and a related device, and the method comprises the steps: obtaining the polarization parameters of a cornea under the configuration parameters of each light cutting band, and the polarization parameters comprise a phase delay map and a fast axis direction map; the phase delay map is used for representing the change of a phase delay parameter along with the position, and the fast axis direction map is used for representing the change of a fast axis direction parameter along with the position; fusing the plurality of phase delay maps under the light-cut band configuration parameters based on a hierarchical weight fusion strategy to obtain a phase delay map dominated by the cornea anterior surface structure, and fusing the plurality of fast axis direction maps under the light-cut band configuration parameters based on a loop statistical strategy to obtain a phase delay map dominated by the cornea anterior surface structure. And obtaining a fast axis direction map dominated by the cornea anterior surface structure. The measurement result obtained by the embodiment of the invention can more truly reflect the collagen arrangement state of the cornea anterior elastic layer and the superficial layer matrix, and the reliability of the method in fine diagnosis is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of ophthalmic optical testing and slit-lamp imaging technology, and in particular to a method and related apparatus for layered measurement of polarization parameters of the anterior corneal surface structure. Background Technology

[0002] The corneal stroma is composed of multiple layers of collagen fiber lamellae with varying orientations, and the integrity of its microstructure directly determines the mechanical stability and optical transparency of the cornea. Polarization-based measurement techniques can non-invasively characterize the arrangement of collagen fibers by acquiring phase retardation and fast-axis orientation, which has significant clinical value in the early diagnosis of keratoconus, refractive surgery risk assessment, and corneal disease monitoring.

[0003] Traditional corneal polarization measurement systems typically employ full-aperture illumination, where the beam covers a large area of ​​the cornea for overall detection. However, because the corneal stroma is a complex anisotropic medium composed of multiple layers of collagen plates with different orientations, when a wide beam penetrates, scattered signals from different depths mix at the detector. This multilayer scattering effect means that the received polarization signal is actually an integral of information from each layer, rather than a true reflection of a single layer.

[0004] The direct consequence of this is a significant decrease in the interpretability of structural indicators: the calculated polarization delay and fast axis direction are often "average values" or "fuzzy values," making it difficult to distinguish whether the lesion occurs in the superficial or deep layers, and also unable to accurately quantify the structural abnormalities of specific lamellar layers. This "black box" measurement result limits its reliability in fine diagnosis, making it difficult for doctors to make accurate clinical decisions based on fuzzy macroscopic indicators. Summary of the Invention

[0005] This application provides a method and related apparatus for layered measurement of polarization parameters of the anterior corneal surface structure. The measurement results can more realistically reflect the collagen arrangement state of the anterior elastic layer and superficial stroma of the cornea, significantly improving its reliability in fine diagnosis.

[0006] The first aspect of this application provides a method for layered measurement of polarization parameters of the anterior corneal surface structure, the method comprising: The polarization parameters of the cornea under each cut-off band configuration parameter are obtained. The polarization parameters include a phase retardation map and a fast axis orientation map. The phase retardation map is used to characterize the change of the phase retardation parameter with position, and the fast axis orientation map is used to characterize the change of the fast axis orientation parameter with position. A phase retardation map dominated by the anterior corneal surface structure is obtained by fusing multiple phase retardation maps under the configuration parameters of the aforementioned shear bands based on a hierarchical weight fusion strategy. Similarly, a fast axis direction map dominated by the anterior corneal surface structure is obtained by fusing multiple fast axis direction maps under the configuration parameters of the aforementioned shear bands based on a circumferential statistical strategy.

[0007] Optionally, obtaining the polarization parameters of the cornea under each cut-off band configuration parameter includes: Obtain the configured light-cutting strip configuration parameter set, which includes multiple light-cutting strip configuration parameters; For each of the described light-cutting bands, a corresponding polarization state is generated based on the configured parameters. The polarization state is input to a metasurface polarization analyzer to obtain polarization measurement data output by the metasurface polarization analyzer; Solve for the Stokes parameters or Mueller matrix based on the polarization measurement data; By decomposing the Stokes parameters or Mueller matrix, a phase delay map and a fast axis orientation map of the cornea are obtained.

[0008] Optionally, the light-cutting band configuration parameters include the incident angle of light on the cornea, and the layered weighted fusion strategy is: , in, A phase delay map dominated by the anterior corneal surface structures. For the first Phase delay map under strip cut optical band configuration parameters. For phase delay parameters, For location, For the first Depth weights corresponding to the configuration parameters of the strip-cut light strip Configure an index for the cut light strip.

[0009] Optionally, the depth weights of the different cut-off band configuration parameters are determined according to a layered weighting function, which is: , in, For the first Depth weighting of the configuration parameters for strip-cut optical strips For equivalent depth, the equivalent depth refers to the first... The equivalent center position of the sensitivity of the strip-cut light band configuration parameters to corneal depth direction. For the first The attenuation factor corresponding to the configuration parameters of the strip-cut optical strip.

[0010] Optionally, the circumferential statistical strategy is as follows: , in, A fast-axis map dominated by the anterior corneal surface structures. For the first Map of the fast axis direction under the configuration parameters of the strip-cut light strip. For the fast axis direction parameter, For location, Configure an index for the cut light strip.

[0011] Optionally, the method further includes: The confidence level is calculated using double-angle circumferential statistics based on the π-periodicity of the fast axis direction map under the aforementioned tangent band configuration parameters. This confidence level measures the consistency of the fast axis direction under multiple tangent band configurations. The confidence level calculation formula is as follows: , in, For confidence level, The effective number of light strips to be configured. For the first Map of the fast axis direction under the configuration parameters of the strip-cut light strip. The imaginary unit is the direction of the fast axis. and Equivalently, after taking the complex exponential modulus, the confidence level range is [0,1], and the closer the value is to 1, the higher the consistency.

[0012] Optionally, the light-cutting band configuration parameters may also include: the physical width of the light-cutting band, the observation angle of the imaging system, and the exposure parameters.

[0013] A second aspect of this application provides a layered measurement device for polarization parameters of the anterior corneal surface structure, the device comprising: The information acquisition unit is used to acquire the polarization parameters of the cornea under each cut-off band configuration parameter. The polarization parameters include a phase retardation map and a fast axis orientation map. The phase retardation map is used to characterize the change of the phase retardation parameter with position, and the fast axis orientation map is used to characterize the change of the fast axis orientation parameter with position. The parameter measurement unit is used to fuse phase delay maps under multiple shear band configuration parameters based on a hierarchical weight fusion strategy to obtain a phase delay map dominated by the anterior corneal surface structure, and to fuse fast axis direction maps under multiple shear band configuration parameters based on a circumferential statistical strategy to obtain a fast axis direction map dominated by the anterior corneal surface structure.

[0014] A third aspect of this application provides an electronic device, including: a processor and a memory; The processor is connected to a memory, wherein the memory is used to store computer programs and the processor is used to invoke the computer programs to execute the methods as described in the first aspect of the embodiments of this application.

[0015] A fourth aspect of this application provides a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a processor, perform the method as described in the first aspect of this application.

[0016] This application abandons the traditional integral measurement mode under a single configuration, and constructs a rich information dimension by utilizing the differences in sensitivity of different configurations to different corneal depths. For the phase delay map, a hierarchical weighted fusion strategy is adopted, which can adaptively weight the response weight of the anterior surface layer according to each configuration parameter. This method effectively suppresses the interference of deep stromal scattering signals and purifies the phase delay information dominated by the anterior surface structure of the cornea from the mixed signal. Therefore, it can more realistically reflect the collagen arrangement state of the anterior elastic lamina and superficial stroma of the cornea, and significantly improve its reliability in fine diagnosis. For the fast axis direction, a vector parameter with periodicity and direction sensitivity, this invention does not simply follow the scalar averaging algorithm, but instead proposes an original circumferential statistical strategy. This strategy fully considers the circumferential characteristics of angle data and the distribution patterns under multiple configurations. It can robustly determine the fast axis direction dominated by the anterior corneal surface structure when there is local noise or directional ambiguity in the configuration data of multiple shear bands. It can effectively avoid the direction cancellation or false direction phenomenon caused by traditional linear averaging, and ensure the spatial continuity and physical accuracy of the generated fast axis direction map, providing a reliable basis for analyzing the microscopic orientation of collagen fibers. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a slit-cutting band polarization measurement system provided in one embodiment of this application is shown; Figure 2 A schematic flowchart of a method for layered measurement of polarization parameters of the anterior corneal surface structure provided in one embodiment of this application is shown. Figure 3 This invention provides a schematic diagram of a layered measurement device for polarization parameters of the anterior corneal surface structure according to an embodiment of the present application. Figure 4A schematic diagram of the structure of a computer device provided in one embodiment of this application is shown. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] Please refer to Figure 1 This diagram illustrates a slit-cutting band polarization measurement system according to an embodiment of this application. Wherein: The slit lamp body (100) provides stable mechanical support, an illumination channel, and an observation channel; the observation path (101) is used to collect corneal reflected light and direct it to subsequent analysis components.

[0021] The illumination path (110) is used to project a preset polarized illumination onto the corneal surface, and the scission band (111) is used to define the width, direction and incident geometry of the illumination beam, thereby forming different scission band configuration parameters.

[0022] An optional polarization state generator (PSG) (130) is used to switch the incident polarization state on the input side; an input state switch (131) is used to switch between multiple linear polarization states or other preset polarization states to facilitate subsequent polarization measurements.

[0023] A pluggable module (120) is set on the output side of the observation path (101) to complete polarization analysis and imaging; wherein, the metasurface polarization state analyzer (PSA) (121) is used to decompose the returned light into multiple polarization analysis channels, the imaging lens group (122) is used to image the light field corresponding to the analysis channel onto the camera (123), and the camera (123) is used to acquire images of each channel.

[0024] The eye (200) represents the object being measured, and the scattering / reflecting medium (210) represents the scattering, reflection, and birefringence modulation of incident polarized light by the anterior surface and superficial stroma of the cornea.

[0025] The data link (310) is used to transmit the image data and corresponding configuration parameters acquired by the camera (123) to the processing unit (300); the processing unit (300) is used to perform parameter acquisition control, Stokes parameter or Mueller matrix solving, phase delay and fast axis direction reconstruction, layer fusion, quality gating, report export and other processing.

[0026] When the system is working, the illumination path (110) emits tangential illumination to the cornea under given incident angle, tangential width, observation angle and exposure settings; the corneal modulated return light enters the pluggable module (120) through the observation path (101), polarization analysis is completed by the metasurface PSA (121), and multi-channel imaging is completed by the imaging lens group (122) and the camera (123); the processing unit (300) reconstructs and fuseds the data under multiple tangential configurations, thereby outputting a phase delay map and fast axis orientation map dominated by the anterior corneal surface structure.

[0027] Please refer to Figure 2 This document illustrates a flowchart of a method for layered measurement of polarization parameters of the anterior corneal surface structure according to an embodiment of this application. This method can be applied to computer devices, which refer to electronic devices capable of data computation and processing. The method may include the following steps: Step 201: Obtain the polarization parameters of the cornea under each cut-off band configuration parameter. The polarization parameters include a phase retardation map and a fast axis orientation map. The phase retardation map is used to characterize the change of the phase retardation parameter with position, and the fast axis orientation map is used to characterize the change of the fast axis orientation parameter with position.

[0028] Among these, the cut-off band configuration parameters are the core variables for achieving layered measurement of the anterior corneal surface structure. It is not a single physical quantity, but rather a set of controllable beam geometry and polarization state parameters. For example, the cut-off band configuration parameters include: the incident angle of light on the cornea, the physical width of the cut-off band, the observation angle of the imaging system, and the exposure parameters.

[0029] The incident angle of light on the cornea is the angle between the illumination optical axis and the corneal surface normal. The larger the incident angle, the longer the propagation path of light in the corneal tissue, which increases the probability of photon interaction with deep stromal collagen fibers, thereby introducing more deep signals.

[0030] The physical width of the cut-off band is the physical width of the slit beam projected onto the cornea. The narrow beam has excellent axial resolution, primarily exciting and collecting scattered light from the focal plane (anterior surface), while deep defocus signals are suppressed by spatial filtering. The wide beam has high luminous flux and a high signal-to-noise ratio, but loses depth resolution, receiving a mixed signal across the entire cornea.

[0031] In an imaging system, the observation angle is the angle between the camera's imaging optical axis and the corneal surface normal, typically forming an angle with the illumination optical axis. The observation angle determines the direction of scattered photons the camera can collect, thus determining the scattering collection efficiency. Changing the observation angle is equivalent to changing the vector direction of the probe light, thereby altering the sensitivity to collagen fibers with specific orientations.

[0032] Exposure parameters include the camera's integration time (shutter speed), gain, and ISO. The reflectivity and scattering intensity vary greatly across different regions of the cornea. Fixed exposure can lead to saturation in bright areas or excessive noise in low-light areas. The calculation of polarization parameters is extremely sensitive to the accuracy of light intensity measurements; a low signal-to-noise ratio can directly cause phase delay and drastic jumps in the fast axis direction.

[0033] Specifically, obtaining the polarization parameters of the cornea under each cut-off band configuration parameter includes: Obtain the configured light-cutting strip configuration parameter set, which includes multiple light-cutting strip configuration parameters; For each of the described light-cutting bands, a corresponding polarization state is generated based on the configured parameters. The polarization state is input to a metasurface polarization analyzer to obtain polarization measurement data output by the metasurface polarization analyzer; Solve for the Stokes parameters or Mueller matrix based on the polarization measurement data; By decomposing the Stokes parameters or Mueller matrix, a phase delay map and a fast axis orientation map of the cornea are obtained.

[0034] Exemplary light-cutting band configuration parameter set Includes configuration parameters for multiple beam cutting strips, and configuration parameters for each beam cutting strip. It can include a set of various parameters, such as the angle of incidence. Physical width Observation angle of the imaging system Exposure parameters .

[0035] For example, for different light-cutting band configuration parameters The system controls the light source or polarization state generator to produce specific incident polarized light. For example, when the cut band is narrow (light intensity is weak), a linear polarization state with higher transmittance may be selected; when it is necessary to detect fibers in a specific direction, the incident polarization angle may be rotated to match the expected fast axis.

[0036] For example, the metasurface polarization analyzer forms at least four polarization analysis channels within the same exposure window based on the input polarization state, such as light intensities at angles of 0°, 45°, 90°, and 135°. , , , The obtained polarization measurement data is used with the observation vector If we express this as an expression, then the relationship between the observation vector and the light intensity is: .

[0037] Among them, the Stokes vector It is a column vector consisting of four real numbers that can completely describe the intensity and polarization state of a beam of light (including fully polarized, partially polarized, and unpolarized light). For example, it can be represented as... , Total light intensity , For linearly polarized components, It represents the circular polarization component.

[0038] When the input is a single polarization state, the Stokes parameters are obtained by solving the polarization measurement data. For example, the relationship between the two is as follows: ,in, For system matrix or measurement matrix, This is the noise term.

[0039] At this point, it can also be based on the Stokes vector. Determine the degree of linear polarization and total polarization degree ,in, , .

[0040] Among them, the Mueller matrix It is a 4×4 real matrix that describes how the polarization state of light changes after passing through an optical element or medium (such as the cornea).

[0041] When the input is a multi-polarization state, the result obtained by solving the polarization measurement data is the Mueller matrix. For example, the relationship between the two is as follows: ,in, In the first incident polarization state and the Under each analytical state In position The scalar output signal (usually light intensity) measured at the point. This is the noise term. After multiple stacked measurements, it can be solved using a constrained / regular approach: , in, The estimated value of the Mueller matrix. This is a regularization term.

[0042] Among them, the phase retardation map is used to characterize the magnitude of phase retardation caused by birefringence at various locations of the cornea, and the fast axis direction map is used to characterize the change of the birefringence principal axis direction with position.

[0043] For example, for purely linear birefringence, Stokes parameter decomposition is used to determine the circular polarization components. Typically close to 0, the main information is concentrated on and Therefore, the direction of the fast axis determines the principal direction of birefringence, and the fast axis direction map can be represented as: .

[0044] Phase retardation reflects the strength of birefringence (proportional to corneal thickness and birefringence). It is determined by the "latitude" of the polarization state on the Poincaré sphere: , The polarization degree of the incident light.

[0045] For example, the Mueller matrix can be decomposed as follows: , For the depolarization matrix, Let be the delay matrix. Let be the dichroism matrix. The fast axis direction map can be represented as: , For matrix The first in Line number Column elements, This is a submatrix of size 3×3 that contains only birefringence information after purification.

[0046] , For matrix The traces.

[0047] Step 202: Based on the hierarchical weighted fusion strategy, the phase delay maps under multiple shear band configuration parameters are fused to obtain a phase delay map dominated by the anterior corneal surface structure, and based on the circumferential statistical strategy, the fast axis direction maps under multiple shear band configuration parameters are fused to obtain a fast axis direction map dominated by the anterior corneal surface structure.

[0048] The hierarchical weight fusion strategy is as follows: , in, A phase delay map dominated by the anterior corneal surface structures. For the first Phase delay map under strip cut optical band configuration parameters. For phase delay parameters, For location, For the first Depth weights corresponding to the configuration parameters of the strip-cut light strip Configure an index for the cut light strip.

[0049] The depth weights of the different cut-off band configuration parameters are determined according to a layered weighting function, which is: , in, For the first Depth weighting of the configuration parameters for strip-cut optical strips For equivalent depth, the equivalent depth refers to the first... The equivalent center position of the sensitivity of the strip-cut light band configuration parameters to corneal depth direction. For the first The attenuation factor corresponding to the configuration parameters of the strip-cut optical band. The equivalent depth can be determined based on the depth-sensitivity function, for example: , in, For depth variables, For the first The depth-sensitive function is configured according to the strip-cut light band, and the integration region is the depth interval corresponding to the target corneal layer. This depth-sensitive function can be calculated by an optical path model or measured from a calibrated sample.

[0050] Different cut-off band configurations (incident angle, bandwidth, viewing angle, exposure) contribute differently to different corneal depths. This is used to quantify this "preference for depth" into a scalar. The smaller the value, the more the configuration is biased towards surface-level information; A larger value indicates a greater bias towards deeper layers or overall mixed information. Therefore, the depth weighting function can increase the contribution of surface-sensitive configuration to the "precursor corneal structure dominance" result.

[0051] The circumferential statistical strategy is as follows: in, A fast-axis map dominated by the anterior corneal surface structures. For the first Map of the fast axis direction under the configuration parameters of the strip-cut light strip. For the fast axis direction parameter, This refers to a planar position.

[0052] Furthermore, the method also includes: The confidence level is calculated using double-angle circumferential statistics based on the π-periodicity of the fast axis direction map under the aforementioned tangent band configuration parameters. This confidence level measures the consistency of the fast axis direction under multiple tangent band configurations. The confidence level calculation formula is as follows: in, For confidence level, The effective number of light strips to be configured. For the first Map of the fast axis direction under the configuration parameters of the strip-cut light strip. The unit is the imaginary unit. The direction of the fast axis is equivalent to θ and θ+π. After taking the complex exponent modulus, the confidence level range is [0,1], and the closer the value is to 1, the higher the consistency.

[0053] As can be seen, this application abandons the traditional integral measurement mode under a single configuration and constructs a rich information dimension by utilizing the differences in sensitivity of different configurations to different corneal depths. For the phase delay map, a hierarchical weighted fusion strategy is adopted, which can adaptively weight the response weights of the anterior surface layer according to each configuration parameter. This method effectively suppresses the interference of deep stromal scattering signals and purifies the phase delay information dominated by the anterior corneal surface structure from the mixed signal. Therefore, it can more realistically reflect the collagen arrangement state of the anterior elastic lamina and superficial stroma of the cornea, significantly improving its reliability in fine diagnosis. For the fast axis direction, a vector parameter with periodicity and direction sensitivity, this invention does not simply follow the scalar averaging algorithm, but instead innovatively proposes a circumferential statistical strategy. This strategy fully considers the circumferential characteristics of angle data and the distribution patterns under multiple configurations. It can robustly determine the fast axis direction dominated by the anterior corneal surface structure when there is local noise or directional ambiguity in the configuration data of multiple shear bands. It can effectively avoid the direction cancellation or false direction phenomenon caused by traditional linear averaging, and ensure the spatial continuity and physical accuracy of the generated fast axis direction map, providing a reliable basis for analyzing the microscopic orientation of collagen fibers.

[0054] Furthermore, the method in this application also includes: The system outputs a report and an export package. The report includes layered results and full-aperture results. The layered results include a difference map or consistency index between the phase delay map and the fast axis orientation map obtained through layered fusion. The full-aperture results include a difference map or consistency index between the corresponding phase delay map and the fast axis orientation map obtained without layered selection or using full-aperture or full-configuration aggregation. The export package includes the cut-off band configuration parameters, quality gating reason codes, layered maps, and region-of-interest statistics. The layered maps include a phase delay map and a fast axis orientation map dominated by the anterior corneal surface structures.

[0055] Furthermore, before outputting the report and exporting the package, the method also includes: The system performs quality gating and records the corresponding quality gating reason code when the quality gating fails. The quality gating includes at least one of the following: cut-off band configuration parameter range gating, cut-off band alignment gating, and general quality gating. The cut-off band configuration parameter range gating is used to determine whether the incident angle, cut-off band physical width, observation angle, and exposure parameters are within a preset allowable range. The cut-off band alignment gating is used to determine whether the cut-off band center position offset, angle deviation, and width error are lower than a preset threshold. The general quality gating is used to determine whether the image sharpness, saturation ratio, motion blur, signal-to-noise ratio, effective coverage, and residual meet the requirements.

[0056] For example, for configuration out of range, the quality gating reason code could be RC_CFG_RANGE; for alignment offset too large, the quality gating reason code could be RC_ALIGN_OFFSET; for oversaturation, the quality gating reason code could be RC_SATURATION; and for insufficient signal-to-noise ratio, the quality gating reason code could be RC_LOW_SNR, etc.

[0057] Furthermore, the image sharpness is represented by average grayscale, the saturation ratio is represented by the proportion of saturated pixels, and the method further includes: When the average gray level is below the lower limit, the saturated pixel ratio is above the upper limit, or the signal-to-noise ratio is insufficient, the exposure time or camera gain is automatically adjusted.

[0058] Furthermore, the image sharpness is represented by the contrast of the cut-off edge, and the effective coverage or the solved residual is represented by the layer separation capability or bandwidth. The method further includes: When the contrast at the edge of the cut light strip is insufficient, the layer separation capability is poor, or the bandwidth causes interlayer aliasing, adjust the width of the cut light strip.

[0059] Furthermore, the method also includes: If the current angle configuration causes insufficient effective coverage, excessive residuals leading to alignment difficulties, excessive residuals, or insufficient effective coverage resulting in equivalent depth deviation from the target layer, then switch the angle configuration.

[0060] Figure 3 A schematic diagram of a layered measurement device for polarization parameters of the anterior corneal surface structure according to an embodiment of this application is shown. The device includes: The information acquisition unit 301 is used to acquire the polarization parameters of the cornea under each cut-off band configuration parameter. The polarization parameters include a phase retardation map and a fast axis orientation map. The phase retardation map is used to characterize the change of the phase retardation parameter with position, and the fast axis orientation map is used to characterize the change of the fast axis orientation parameter with position. The parameter measurement unit 302 is used to fuse phase delay maps under multiple shear band configuration parameters based on a hierarchical weight fusion strategy to obtain a phase delay map dominated by the anterior corneal surface structure, and to fuse fast axis direction maps under multiple shear band configuration parameters based on a circumferential statistical strategy to obtain a fast axis direction map dominated by the anterior corneal surface structure.

[0061] Figure 4 A schematic diagram of the structure of a computer device provided in one embodiment of this application is shown, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the function of the computer system of the method for layered measurement of polarization parameters of the anterior corneal surface structure in any of the above embodiments.

[0062] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a computer, causes the computer to perform the functions of a computer system for the method of layered measurement of polarization parameters of the anterior corneal surface structure in any of the above embodiments.

[0063] This application also provides a computer program product containing instructions that, when executed by a computer, cause the computer to perform the functions of the computer system of the method for layered measurement of polarization parameters of the anterior corneal surface structure in any of the above embodiments.

[0064] It is understood that the specific examples in this application are only intended to help those skilled in the art better understand the implementation methods of this application, and are not intended to limit the scope of the invention.

[0065] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not limit the implementation process of the embodiments of this application in any way.

[0066] It is understood that the various implementation methods described in this application can be implemented individually or in combination, and the implementation methods in this application are not limited in this respect.

[0067] Unless otherwise stated, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0068] It is understood that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0069] It is understood that the memory in the embodiments of this application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Specifically, non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM). It should be noted that the memory in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0070] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0071] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the aforementioned method implementations, and will not be repeated here.

[0072] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only 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 mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0073] 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 network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0074] In addition, the functional units in the various embodiments of this application 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.

[0075] If a function 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 this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. The 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 various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0076] The above are merely specific embodiments of this application, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A method for layered measurement of polarization parameters of the anterior corneal surface structure, characterized in that, The method includes: The polarization parameters of the cornea under each cut-off band configuration parameter are obtained. The polarization parameters include a phase retardation map and a fast axis orientation map. The phase retardation map is used to characterize the change of the phase retardation parameter with position, and the fast axis orientation map is used to characterize the change of the fast axis orientation parameter with position. A phase retardation map dominated by the anterior corneal surface structure is obtained by fusing multiple phase retardation maps under the configuration parameters of the aforementioned shear bands based on a hierarchical weight fusion strategy. Similarly, a fast axis direction map dominated by the anterior corneal surface structure is obtained by fusing multiple fast axis direction maps under the configuration parameters of the aforementioned shear bands based on a circumferential statistical strategy.

2. The method according to claim 1, characterized in that, The acquisition of the polarization parameters of the cornea under each cut-off band configuration parameter includes: Obtain the configured light-cutting strip configuration parameter set, which includes multiple light-cutting strip configuration parameters; For each of the described light-cutting bands, a corresponding polarization state is generated based on the configured parameters. The polarization state is input to a metasurface polarization analyzer to obtain polarization measurement data output by the metasurface polarization analyzer; Solve for the Stokes parameters or Mueller matrix based on the polarization measurement data; By decomposing the Stokes parameters or Mueller matrix, a phase delay map and a fast axis orientation map of the cornea are obtained.

3. The method according to claim 1, characterized in that, The light-cutting band configuration parameters include the incident angle of light on the cornea, and the layered weighted fusion strategy is as follows: ， in, A phase delay map dominated by the anterior corneal surface structures. For the first Phase delay map under strip cut optical band configuration parameters. For phase delay parameters, For location, For the first Depth weights corresponding to the configuration parameters of the strip-cut light strip Configure an index for the cut light strip.

4. The method according to claim 3, characterized in that, The depth weights of the different cut-off band configuration parameters are determined according to a layered weighting function, which is: ， in, For the first Depth weighting of the configuration parameters for strip-cut optical strips For equivalent depth, the equivalent depth refers to the first... The equivalent center position of the sensitivity of the strip-cut light band configuration parameters to corneal depth direction. For the first The attenuation factor corresponding to the configuration parameters of the strip-cut optical strip.

5. The method according to claim 1, characterized in that, The circumferential statistical strategy is as follows: ， in, A fast-axis map dominated by the anterior corneal surface structures. For the first Map of the fast axis direction under the configuration parameters of the strip-cut light strip. For the fast axis direction parameter, For location, Configure an index for the cut light strip.

6. The method according to claim 5, characterized in that, The method further includes: According to the fast axis direction map under the aforementioned shear band configuration parameters The confidence level is periodically calculated using double-angle circumferential statistics. This confidence level measures the consistency of the fast axis direction under multiple tangential band configurations. The confidence level calculation formula is as follows: ， in, For confidence level, The effective number of light strips to be configured. For the first Map of the fast axis direction under the configuration parameters of the strip-cut light strip. The imaginary unit is the direction of the fast axis. and Equivalently, after taking the complex exponential modulus, the confidence level range is [0,1], and the closer the value is to 1, the higher the consistency.

7. The method according to claim 2, characterized in that, The light-cutting band configuration parameters also include: the physical width of the light-cutting band, the observation angle of the imaging system, and the exposure parameters.

8. A device for layered measurement of polarization parameters of the anterior corneal surface structure, characterized in that, The device includes: The information acquisition unit is used to acquire the polarization parameters of the cornea under each cut-off band configuration parameter. The polarization parameters include a phase retardation map and a fast axis orientation map. The phase retardation map is used to characterize the change of the phase retardation parameter with position, and the fast axis orientation map is used to characterize the change of the fast axis orientation parameter with position. The parameter measurement unit is used to fuse phase delay maps under multiple shear band configuration parameters based on a hierarchical weight fusion strategy to obtain a phase delay map dominated by the anterior corneal surface structure, and to fuse fast axis direction maps under multiple shear band configuration parameters based on a circumferential statistical strategy to obtain a fast axis direction map dominated by the anterior corneal surface structure.

9. An electronic device, characterized in that, include: Processor and memory; The processor is connected to a memory, wherein the memory is used to store a computer program, and the processor is used to invoke the computer program to perform the method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, perform the method as described in any one of claims 1-7.

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