An anterior segment optical coherence tomography image measurement method and system

Abstract

The present application belongs to the technical field of anterior segment image measurement, in order to solve the problems of poor scanning adaptation and low signal-to-noise ratio existing in the prior art of anterior segment imaging, an anterior segment optical coherence tomography image measurement method and system are provided, the anterior segment is pre-scanned by collecting light beams along the optical axis direction of the anterior segment, the anterior segment tomography images collected along the optical axis direction are scanned, the theoretical boundary position of the anterior segment under the axial detection signal is determined by data fitting, the optical path difference of the anterior segment at different scanning positions is considered, the theoretical boundary position of the anterior segment under the axial detection signal is corrected, and the actual boundary curve of the anterior segment under the axial detection signal is obtained, the normal direction of the anterior segment surface along the actual boundary curve is scanned at equal intervals, the flattened anterior segment boundary is restored based on the anterior segment tomography images collected under the normal direction equal interval scanning, and high-quality anterior segment OCT imaging is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of anterior segment image measurement, and particularly relates to a method and system for measuring anterior segment optical coherence tomography images. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Optical coherence tomography (OCT) is a technique that uses weak interference signals to perform three-dimensional measurements of samples. The intensity of the OCT measurement signal is related to the angle of the incident light; when the incident light is perpendicular to the surface being measured, the backscattered beam is stronger, thus increasing the interference intensity between the sample and the reference arm spectrum. High-quality OCT imaging of the anterior segment can non-invasively quantify key structural parameters of the cornea, anterior chamber, angle, and lens. It is a core basis for glaucoma screening, assessment of angle closure risk, preoperative planning for ICL implantation, diagnosis of corneal lesions, cataract assessment, and postoperative follow-up after refractive surgery, providing objective imaging support for accurate diagnosis and treatment and surgical safety.

[0004] Existing detection methods all employ a fixed-point, large-field-of-view scanning method for single-frame imaging, and improve the signal-to-noise ratio (SNR) through multi-frame averaging. However, the curvature radius of the anterior segment of an individual can range from 7.0 to 9.5 mm, and its shape (spherical, aspherical, symmetrical) varies greatly. This directly affects the return interference signal of light in areas with weak reflective signals, such as the cornea, under fixed scanning methods, resulting in a significant decrease in the SNR at some locations, making it impossible to effectively observe the internal structure. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a method and system for measuring anterior segment optical coherence tomography images, thereby achieving high-quality imaging of anterior segment optical coherence tomography images.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for measuring anterior segment optical coherence tomography images, comprising:

[0008] The anterior segment is pre-scanned using a beam of light along the optical axis of the anterior segment to acquire tomographic images of the anterior segment;

[0009] For the anterior segment tomographic images acquired along the optical axis of the anterior segment, the theoretical boundary position of the anterior segment under axial detection signal is determined by data fitting.

[0010] Considering the optical path difference at different scanning positions of the anterior segment, the theoretical boundary position of the anterior segment under axial detection signal is corrected to obtain the actual boundary curve of the anterior segment under axial detection signal;

[0011] An isometric scan of the anterior segment surface along the normal direction of the actual boundary curve is performed to obtain an anterior segment tomographic image composed of axial detection signals from multiple acquisition positions.

[0012] Based on the anterior segment tomographic images acquired under equidistant scanning in the normal direction, the flattened anterior segment boundary is restored, achieving high-quality imaging of anterior segment optical coherence tomography images.

[0013] In a second aspect, the present invention provides an anterior segment optical coherence tomography image measurement system, comprising:

[0014] The pre-scanning module is configured to pre-scan the anterior segment using a collection beam along the optical axis of the anterior segment, and acquire tomographic images of the anterior segment.

[0015] The calculation module is configured to: determine the theoretical boundary position of the anterior segment under axial detection signal by means of data fitting for the tomographic scan image of the anterior segment acquired by scanning along the optical axis of the anterior segment;

[0016] The correction module is configured to: consider the optical path difference at different scanning positions of the anterior segment, correct the theoretical boundary position of the anterior segment under the axial detection signal, and obtain the actual boundary curve of the anterior segment under the axial detection signal;

[0017] The scanning module is configured to perform equidistant scanning of the anterior segment surface along the normal direction of the actual boundary curve, and acquire an anterior segment tomographic image composed of axial detection signals from multiple acquisition positions of the anterior segment.

[0018] The imaging module is configured to: restore the flattened anterior segment boundary based on the anterior segment tomographic images acquired under isometric scanning in the normal direction, thereby achieving high-quality imaging of the anterior segment optical coherence tomographic images.

[0019] Thirdly, the present invention provides an electronic device including a memory and a processor, and computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, perform the method described in the first aspect.

[0020] Fourthly, the present invention provides a computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in the first aspect.

[0021] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect.

[0022] The above one or more technical solutions have the following beneficial effects:

[0023] In this invention, a beam of light is used to pre-scan the anterior segment along the optical axis. Based on the anterior segment tomographic image, the theoretical boundary position of the anterior segment under the axial detection signal is determined by data fitting, and the theoretical boundary position is corrected based on the optical path difference. The surface of the anterior segment is scanned at equal intervals along the normal direction of the actual boundary curve, and the flattened anterior segment boundary is restored based on the anterior segment tomographic image acquired under the normal direction equal interval scan, thereby achieving high-quality imaging of the anterior segment optical coherence tomographic image.

[0024] In this invention, during the pre-scan, a single-line repeated scan is performed at the same location to obtain the precise contour of the anterior segment surface; multiple acquired tomographic scan images are registered and averaged to reduce the influence of noise on the boundary.

[0025] In this invention, at each acquisition location, a main acquisition point and multiple auxiliary acquisition points are designed for repeated acquisition. The axial detection signal at the acquisition location is then averaged in terms of time, space, and signal phase, thereby suppressing speckle noise and improving the signal-to-noise ratio.

[0026] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0028] Figure 1 This is a schematic diagram of the optical path of the anterior segment of the sample arm in Embodiment 1 of the present invention;

[0029] Figure 2 This is a schematic diagram of anterior segment OCT imaging in Embodiment 1 of the present invention;

[0030] Figure 3 This is a schematic diagram of A-Line signal acquisition in the anterior segment of the present invention, according to Embodiment 1.

[0031] Figure 4 This is a schematic diagram showing the relationship between the coordinates of the OCT system and the coordinates of the interferometric image in Embodiment 1 of the present invention;

[0032] Figure 5 This is a schematic diagram of the OCT system and acquisition location in Embodiment 1 of the present invention;

[0033] Figure 6This is a schematic diagram of the joint control path deviation compensation of the OCT system in Embodiment 1 of the present invention;

[0034] Figure 7 This is a schematic diagram of the anterior segment lens orientation during signal acquisition in Embodiment 1 of the present invention;

[0035] Figure 8 This is a schematic diagram of high-quality anterior segment B-scan image reconstruction in Embodiment 1 of the present invention. Detailed Implementation

[0036] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0038] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0039] Example 1

[0040] This embodiment discloses a method for measuring anterior segment optical coherence tomography images, including:

[0041] The anterior segment is pre-scanned using a beam of light along the optical axis of the anterior segment to acquire tomographic images of the anterior segment;

[0042] For the anterior segment tomographic images acquired along the optical axis of the anterior segment, the theoretical boundary position of the anterior segment under axial detection signal is determined by data fitting.

[0043] Considering the optical path difference at different scanning positions of the anterior segment, the theoretical boundary position of the anterior segment under axial detection signal is corrected to obtain the actual boundary curve of the anterior segment under axial detection signal;

[0044] An isometric scan of the anterior segment surface along the normal direction of the actual boundary curve is performed to obtain an anterior segment tomographic image composed of axial detection signals from multiple acquisition positions.

[0045] Based on the anterior segment tomographic images acquired under equidistant scanning in the normal direction, the flattened anterior segment boundary is restored, achieving high-quality imaging of anterior segment optical coherence tomography images.

[0046] This embodiment achieves parallel beam emission from the anterior segment optical axis by designing an anterior segment scanning system. Secondly, it performs a large field-of-view imaging of the anterior segment in one go, fits the acquired anterior segment boundary, and proposes an anterior segment interferometric signal acquisition method based on varying curvature. Finally, it achieves high signal-to-noise ratio imaging by designing an axial probe signal repetitive scanning protocol, and uses image reconstruction to correct the axial probe signal.

[0047] The following section uses the A-line signal as an axial detection signal as an example to provide a detailed description of the anterior segment optical coherence tomography image measurement method proposed in this embodiment:

[0048] Step 1: Design of the data acquisition system.

[0049] To ensure the acquired beam exits parallel to the optical axis of the anterior segment, the optical path of the acquisition system is designed as follows: Figure 1 As shown. Specifically, lens 1 and lens 2 form a 4f system, where the focal length of lens 1 is... The focal length of lens 2 is The incident light beam onto the sample arm is parallel, and after passing through the reflecting mirror, it forms a beam plane that scans vertically, such as... Figure 1 The different colors represent the scanning beams. The parallel beam passes through the 4f system and then through the anterior segment lens, whose focal length is... The emitted beam is focused into a scanning beam by the anterior segment lens, with the focusing position being the rear focal plane of the anterior segment lens. To ensure the scanning beam exits parallel to the optical axis of the anterior segment, the distance from the reflecting surface of the galvanometer to lens 1 in the optical path is... The distance between lens 1 and lens 2 is The distance between lens 2 and the anterior segment lens is The final scanned region length is shown in the following formula:

[0050] (1)

[0051] In the formula, The length of the scanned region. The angle between the scanning beam and the optical axis of the anterior segment.

[0052] Step 2: Data acquisition system calibration.

[0053] Initially, the optical axis of the device's anterior segment is parallel to the X-axis motion platform. At this point, the angle of the OCT rotation center is zero, and the two-dimensional motion platform is at the midpoint of its travel, i.e., the intersection of the bisectors of the X-axis and Y-axis travel midpoints. This position is the origin of the OCT system coordinates. Figure 5 As shown. The system is then initialized and calibrated: First, the parallel light from the 4f system is emitted along the optical axis of the anterior segment lens. The calibrating reflector is then placed a distance from the center of the anterior segment lens. The reference arm optical path is adjusted to -0.1 mm to prevent interference from zero-frequency noise and artifacts; then the optical path of the reference arm is adjusted to produce zero-frequency interference, at which point the optical path of the reference arm is equal to that of the sample arm.

[0054] Based on this, the system imaging depth is calculated. Complete the association between the OCT system coordinates and the pixel coordinates of the measured interferometric image, whereby... The calculation formula is as follows:

[0055] (2)

[0056] in, The system detects the center wavelength of the beam; The refractive index is 1, and the refractive index of air is 1. This represents the spectral sampling resolution.

[0057] Step 3: A-line data collection method.

[0058] First, the system from step 2 is used to perform large field-of-view imaging of the anterior segment, with the imaging range (i.e., the length of the scanning area) being [missing information]. Covering the cornea and both anterior chamber angles, such as Figure 2 As shown.

[0059] In OCT images of the anterior segment, there exists a weak reflection region. When the incident beam cannot be perpendicular to this region for detection, the interference signal intensity in this region is weak, resulting in a lack of detail in the reconstructed image and even the loss of some structures. This phenomenon is exacerbated in systems with low signal-to-noise ratios. Therefore, to achieve high signal-to-noise ratio measurements of anterior segment images, perpendicular light incidence is the most crucial step. To achieve perpendicular measurement of the surface under test, accurate extraction of the anterior segment boundary is required: First, to obtain the accurate contour of the anterior segment surface, a single-line repeated scan is performed at the same location. Each B-scan image contains 1000 A-Line signals, with an acquisition field of view of L. Multiple acquired B-scan images are registered and averaged to reduce the influence of noise on the boundary. Second, the peak values ​​of the 1000 A-Line signals are acquired, and the index of the first pixel representing the structural peak is selected. As the anterior corneal boundary point, 1000 anterior corneal boundary points were obtained sequentially, such as... Figure 3 As shown.

[0060] Based on this, the coordinates of the interferometric image are obtained. Further steps are needed to map these image coordinates to the OCT system coordinates, such as... Figure 4 As shown, the mapping relationship is as follows:

[0061] (3)

[0062] In the formula, i represents the i-th A-Line, and L is the field of view range for data acquisition. For the system imaging depth, The distance from the center of the anterior segment lens to the center of rotation. Let i be the peak pixel index of the i-th A-Line structure. This represents the x-coordinate of the i-th A-Line in the interferometric image at local pixel coordinates. This represents the ordinate of the i-th A-Line in the interferometric image at local pixel coordinates. Let x be the x-coordinate of the i-th A-Line anterior corneal boundary point in the OCT system coordinate system. Let be the ordinate of the i-th A-Line anterior corneal boundary point in the OCT system coordinate system. and This represents the horizontal and vertical coordinates of the current OCT system, which can be directly obtained from the position encoder and the OCT system coordinate origin.

[0063] Since the boundary of the anterior segment image is in the shape of a quadratic parabola, a quadratic function is used to suppress boundary outliers. The boundary points are obtained by the least squares method, as shown in the following formula.

[0064] (4)

[0065] In the formula, , and For the coefficients of a quadratic function, Let be the independent variable of the fitted function. This is the fitting function in the OCT system coordinate system.

[0066] The theoretical function expression is obtained through equation (4). However, this function ignores the effect of the difference in optical path length between the boundary beam and the central beam of the scanning region on the true morphology of the anterior segment, such as... Figure 1 As shown, the optical path difference between the two sides can be expressed as follows:

[0067] (5)

[0068] In the formula, The angle between the i-th A-Line beam and the optical axis of the anterior segment can be obtained by the galvanometer scanning voltage. For the additional optical path difference of the i-th A-Line beam; is the refractive index coefficient.

[0069] By substituting the optical path difference bias, the accurate surface morphology curve of the anterior segment can be finally obtained as follows:

[0070] (6)

[0071] In the formula, This means that the ordinate of the theoretical boundary position under the i-th A-Line in the OCT system coordinate system is obtained by equation (4). Let y be the ordinate of the actual anterior segment boundary position of the i-th A-Line in the OCT system coordinates.

[0072] Based on the ordinate and corresponding abscissa of the actual anterior segment boundary position of the A-Line in the OCT system coordinate system, the actual anterior segment boundary curve is further fitted using the least squares method. .

[0073] Based on the actual anterior segment boundary curve The entire imaging range L is divided into 1000 equally spaced boundary points along the X-axis. The outward normal direction of the actual anterior segment boundary at each boundary point is obtained, and points are equidistant along the outward normal direction. These are the collection locations. The process iterates through 1000 boundary points to determine all collection locations, forming the collection path. Each collection location can be represented by the following formula:

[0074] (7)

[0075] In the formula, The x-coordinate of the i-th acquisition position in the OCT system coordinate system. Let a and b be the ordinates of the actual anterior segment boundary point in the OCT system coordinates corresponding to the i-th acquisition position; a and b are the actual anterior segment boundary curves. The fitting coefficient; and The x and y coordinates of the i-th acquisition position in the OCT system coordinate system, which is to be reached by the center of the anterior segment lens; L represents the horizontal axis of the current OCT system, which can be obtained directly from the position encoder and the origin of the OCT system coordinates; L is the field of view range of the acquisition.

[0076] Because the distance from the overall rotation center of the equipment to the center of the anterior segment lens is Rotation will cause path deviations on the X and Y axes, such as... Figure 6 As shown in the figure, after correcting the path deviation, the control position and rotation angle of the actual OCT system during acquisition are as follows:

[0077] (8)

[0078] In the formula, It represents the angle between the inner normal direction of the actual anterior segment boundary point corresponding to the i-th acquisition position and the positive direction of the Y-axis, which is also the target value of the i-th control rotation of the OCT rotation system, and clockwise is positive; , Represents the x and y coordinates of the i-th acquisition position; , This represents the target values ​​of the horizontal and vertical coordinates of the i-th control point of the OCT system's two-dimensional motion platform. By acquiring the target values ​​of the horizontal and vertical coordinates and rotation at each acquisition position, a connection is established with the servo drive system, thereby achieving pulse quantity control of the motion distance and angle, and completing the precise positioning of the anterior segment lens center at each acquisition position.

[0079] Multiple exposures at each acquisition location reduce noise and increase the signal-to-noise ratio; the scanning method is designed as follows: Figure 7 As shown. At each acquisition position, repeated acquisitions were performed using adjacent A-Line acquisition points parallel to the optical axis of the anterior segment lens and along the rotation axis. The main acquisition point, indicated by the red circle, is located along the actual anterior segment boundary curve. The point where the normal direction intersects the entire acquisition path; the direction of the main acquisition point follows the actual anterior segment boundary curve. Corresponding to the normal direction of the boundary point, the two auxiliary acquisition points (the black circles) above and below are aligned with the main acquisition point and slightly shifted vertically in space. By controlling the galvanometer voltage to stabilize, signals are acquired from five acquisition points: two adjacent A-Line acquisition points before and after the i-th acquisition position, and the current acquisition point. By performing four repeated acquisitions at each acquisition point, the 20 A-Line signals at the i-th acquisition position are averaged in terms of time, space, and signal phase, thereby suppressing speckle noise and achieving high signal-to-noise ratio (SNR) A-Line acquisition at the i-th acquisition position. This process is repeated from the first acquisition position to the 1000th acquisition position, completing a total of 20,000 A-Line signal acquisitions and 1000 high SNR A-Line acquisitions.

[0080] Step 4: Image reconstruction.

[0081] Step 3 completes the acquisition of anterior segment signals. The acquired 1000 high signal-to-noise ratio (SNR) A-Line signals are then used for image reconstruction to obtain the original B-scan image. Because the acquisition path is always equidistant from the anterior segment boundary during the acquisition process, the anterior segment boundary is flattened after image reconstruction, requiring further processing to obtain a true high SNR B-scan image.

[0082] The reconstruction method is shown in the following formula:

[0083] (9)

[0084] In the formula, and Represents the column and row values ​​in the pixel coordinates of the original B-scan image, where i represents the high signal-to-noise ratio A-Line at the i-th acquisition position. and This represents the column and row values ​​of the reconstructed pixel coordinates. The height of the image is the number of pixel units in the linear array camera of the OCT imaging spectrometer.

[0085] Specifically, this means that the A-Line data collected in step 3 all follow the actual boundary curve of the anterior segment. The normal vector direction has an imaging angle, which is consistent with the rotation angle of the rotary table. like Figure 6 As shown. By using this angle In image reconstruction, the acquired images are rotated sequentially along the last row (where the zero-frequency position of the interferogram is located at the top of the first row), ultimately achieving high-quality imaging of the anterior segment OCT image, such as... Figure 8 As shown.

[0086] Example 2

[0087] The purpose of this embodiment is to provide an anterior segment optical coherence tomography image measurement system, including:

[0088] The pre-scanning module is configured to pre-scan the anterior segment using a collection beam along the optical axis of the anterior segment, and acquire tomographic images of the anterior segment.

[0089] The calculation module is configured to: determine the theoretical boundary position of the anterior segment under axial detection signal by means of data fitting for the tomographic scan image of the anterior segment acquired by scanning along the optical axis of the anterior segment;

[0090] The correction module is configured to: consider the optical path difference at different scanning positions of the anterior segment, correct the theoretical boundary position of the anterior segment under the axial detection signal, and obtain the actual boundary curve of the anterior segment under the axial detection signal;

[0091] The scanning module is configured to perform equidistant scanning of the anterior segment surface along the normal direction of the actual boundary curve, and acquire an anterior segment tomographic image composed of axial detection signals from multiple acquisition positions of the anterior segment.

[0092] The imaging module is configured to: restore the flattened anterior segment boundary based on the anterior segment tomographic images acquired under isometric scanning in the normal direction, thereby achieving high-quality imaging of the anterior segment optical coherence tomographic images.

[0093] In further embodiments, the following is also provided:

[0094] An electronic device includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor. When executed by the processor, the computer instructions perform the method described in Embodiment 1. For brevity, further details are omitted here.

[0095] It should be understood that in this embodiment, the processor can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0096] Memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of memory may also include non-volatile random access memory. For example, memory may also store information about the device type.

[0097] A computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in Embodiment 1.

[0098] The method in Embodiment 1 can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor. The software modules can reside in readily available storage media in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. 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. To avoid repetition, a detailed description is not provided here.

[0099] A computer program product includes a computer program that, when executed by a processor, implements the method described in Embodiment 1.

[0100] The present invention also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, which execute in a device on a target real or virtual processor to perform the processes / methods described above. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or divided among program modules as needed. The machine-executable instructions for the program modules can execute within a local or distributed device. In a distributed device, the program modules can reside in both local and remote storage media.

[0101] The computer program code used to implement the methods of the present invention may be written in one or more programming languages. This computer program code may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the computer or other programmable data processing device, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a computer, partially on a computer, as a stand-alone software package, partially on a computer and partially on a remote computer, or entirely on a remote computer or server.

[0102] In the context of this invention, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, and the like. Examples of signals may include electrical, optical, radio, sound, or other forms of propagation signals, such as carrier waves, infrared signals, etc.

[0103] Those skilled in the art will recognize that the units and algorithm steps described in conjunction with the embodiments 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.

[0104] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for measuring anterior segment optical coherence tomography images, characterized in that, include: The anterior segment is pre-scanned using a beam of light along the optical axis of the anterior segment to acquire tomographic images of the anterior segment; For the anterior segment tomographic images acquired along the optical axis of the anterior segment, the theoretical boundary position of the anterior segment under axial detection signal is determined by data fitting. Considering the optical path difference at different scanning positions of the anterior segment, the theoretical boundary position of the anterior segment under axial detection signal is corrected to obtain the actual boundary curve of the anterior segment under axial detection signal, as follows: The additional optical path difference of the axial probe beam relative to the optical axis of the anterior segment at different scanning positions is determined based on the angle between the axial probe beam at different scanning positions and the optical axis of the anterior segment, as well as the focal length of the beam refraction lens. The theoretical boundary position of the anterior segment of the lower segment under the axial detection signal is corrected based on the additional optical path difference to obtain the actual boundary curve of the anterior segment of the lower segment under the axial detection signal; Based on the actual boundary curve of the anterior segment, the entire imaging range is divided into multiple equally spaced boundary points; the outward normal direction of the actual anterior segment boundary at each boundary point is obtained, and the acquisition position is determined along the outward normal direction at a distance equal to the focal length of the anterior segment lens; all boundary points are traversed to determine all acquisition positions, forming an acquisition path; An isometric scan of the anterior segment surface along the normal direction of the actual boundary curve is performed to obtain an anterior segment tomographic image composed of axial detection signals from multiple acquisition positions. Based on the anterior segment tomographic images acquired under equidistant scanning in the normal direction, the flattened anterior segment boundary is restored, achieving high-quality imaging of anterior segment optical coherence tomography images.

2. The method for measuring anterior segment optical coherence tomography images as described in claim 1, characterized in that, A pre-scan of the anterior segment is performed using a beam of light along the optical axis of the anterior segment to acquire tomographic images of the anterior segment. Specifically: Multiple anterior segment tomographic images were obtained by repeatedly scanning the anterior segment with a beam of light along the optical axis of the anterior segment. Multiple anterior segment tomographic images were registered and averaged to obtain the final anterior segment tomographic image under parallel optical axis scanning.

3. A method for measuring anterior segment optical coherence tomography images as described in claim 1 or 2, characterized in that, Peak values ​​of the axial detection signals contained in the anterior segment tomographic images acquired along the optical axis are extracted, and the index of the first pixel representing the structural peak of the axial detection signal is selected as the anterior corneal boundary point.

4. The method for measuring anterior segment optical coherence tomography images as described in claim 1, characterized in that, Based on the coordinate mapping relationship between the pixel coordinate system of the anterior segment tomographic image acquired along the optical axis and the OCT system coordinate system, the coordinates of the anterior corneal boundary point corresponding to each axial detection signal in the OCT system are calculated. Based on the coordinates of the anterior corneal boundary point corresponding to each axial detection signal in the OCT system, the theoretical boundary position of the anterior segment under the axial detection signal is determined by the least squares method.

5. The method for measuring anterior segment optical coherence tomography images as described in claim 1, characterized in that, When performing equidistant scanning of the anterior segment along the normal direction, multiple acquisitions are performed at each acquisition position. The axial detection signals acquired at each acquisition position are averaged in time, space, and signal phase to obtain the high signal-to-noise ratio axial detection signal for the corresponding acquisition position.

6. The method for measuring anterior segment optical coherence tomography images as described in claim 5, characterized in that, Repeated data collection was performed at each collection location, specifically as follows: The point where the normal direction along the actual anterior segment boundary curve intersects with the entire acquisition path is taken as the main acquisition point. Multiple auxiliary acquisition points are set up after the spatial position is translated and the direction is consistent with that of the main acquisition point. Repeated acquisition is performed at the main acquisition point and the auxiliary acquisition points respectively. The direction of the main acquisition point is along the normal direction of the boundary point corresponding to the actual anterior segment boundary curve.

7. The method for measuring anterior segment optical coherence tomography images as described in claim 1, characterized in that, By incorporating the imaging angles of different acquisition positions into the image reconstruction, the acquired images are rotated sequentially along the last row position by the acquisition angle, thereby achieving high-quality imaging of anterior segment optical coherence tomography images.

8. A method for measuring anterior segment optical coherence tomography images as described in claim 1 or 7, characterized in that, The anterior segment tomographic images acquired under equidistant scanning along the normal direction are reconstructed, specifically as follows: in, and The column and row values ​​in the pixel coordinates of the original scanned image formed by the high signal-to-noise ratio axial detection signal; i represents the high signal-to-noise ratio axial detection signal at the i-th acquisition position; and This represents the column and row values ​​of the reconstructed pixel coordinates; The number of pixel units in the linear array camera of the spectrometer used for optical coherence tomography; This represents the imaging angle at the i-th acquisition position; The x-coordinate of the i-th A-Line anterior corneal boundary point in the acquisition system coordinates; This is the actual anterior segment boundary curve.

9. The method for measuring anterior segment optical coherence tomography images as described in claim 4, characterized in that, The system imaging depth is calculated by probing the center wavelength of the probe beam, the air refractive index, and the spectral sampling resolution; based on the system imaging depth, the pixel coordinates of the anterior segment tomographic images scanned along the optical axis are mapped to the OCT system coordinates.

10. A system for measuring anterior segment optical coherence tomography images, characterized in that, include: The pre-scanning module is configured to pre-scan the anterior segment using a collection beam along the optical axis of the anterior segment, and acquire tomographic images of the anterior segment. The calculation module is configured to: determine the theoretical boundary position of the anterior segment under axial detection signal by means of data fitting for the tomographic scan image of the anterior segment acquired by scanning along the optical axis of the anterior segment; The correction module is configured to: consider the optical path difference at different scanning positions of the anterior segment, correct the theoretical boundary position of the anterior segment under axial detection signal, and obtain the actual boundary curve of the anterior segment under axial detection signal; specifically: The additional optical path difference of the axial probe beam relative to the optical axis of the anterior segment at different scanning positions is determined based on the angle between the axial probe beam at different scanning positions and the optical axis of the anterior segment, as well as the focal length of the beam refraction lens. The theoretical boundary position of the anterior segment of the lower segment under the axial detection signal is corrected based on the additional optical path difference to obtain the actual boundary curve of the anterior segment of the lower segment under the axial detection signal; The scanning module is configured to: divide the entire imaging range into multiple equally spaced boundary points based on the actual boundary curve of the anterior segment; obtain the outward normal direction of the actual anterior segment boundary at each boundary point; determine the acquisition position along the outward normal direction at a distance equidistant from the focal length of the anterior segment lens; and traverse all boundary points to determine all acquisition positions, forming an acquisition path. An isometric scan of the anterior segment surface along the normal direction of the actual boundary curve is performed to obtain an anterior segment tomographic image composed of axial detection signals from multiple acquisition positions. The imaging module is configured to: restore the flattened anterior segment boundary based on the anterior segment tomographic images acquired under isometric scanning in the normal direction, thereby achieving high-quality imaging of the anterior segment optical coherence tomographic images.

11. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, perform the method according to any one of claims 1-9.

12. A computer-readable storage medium, characterized in that, Used to store computer instructions, which, when executed by a processor, perform the method described in any one of claims 1-9.

13. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, implements the method described in any one of claims 1-9.

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