Personalized eyeball model establishing method suitable for finite element simulation

Abstract

The invention provides a personalized eyeball model establishment method suitable for finite element simulation, and relates to the technical field of finite element simulation, and the method specifically comprises the steps: importing an eye OCT image into three-dimensional modeling software, and obtaining structural information; an ellipse is drawn based on the information, the long axis is the length of the equatorial part of the eyeball, and the short axis is twice the distance from the equatorial part to the posterior pole; a quarter of the upper right portion of the cut ellipse is reserved, and the cut ellipse is offset outwards by 1 mm to form an equatorial posterior sclera outline; drawing an eye axis straight line and a cornea thickness straight line, zooming and moving the OCT image to enable the OCT image to coincide with the cornea thickness straight line; drawing a cornea contour and a trabecular mesh contour according to the OCT image, and forming sclera vein sinus after biasing; and symmetrically drawing to obtain a complete section, and rotating by 360 degrees to generate a three-dimensional eyeball model. The method is based on common ophthalmic examination data, is easy to obtain, has high accuracy, can significantly improve the authenticity and precision of the model, and improves the prediction accuracy of ophthalmic diagnosis and treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of finite element simulation, and in particular to a method for establishing a personalized eyeball model suitable for finite element simulation. Background Art

[0002] With the development of computer technology and simulation technology, finite element analysis (FEA) has become an important tool in the fields of engineering and biomedicine. Especially in ophthalmic research, the establishment of a personalized eyeball model is of great significance for understanding the mechanical properties of the eyeball, planning surgery, and evaluating surgical results.

[0003] Traditional eyeball models are often designed using standardized data, which makes it difficult to adapt to the complex problems caused by individual differences. Therefore, how to effectively establish a personalized eyeball model has become one of the research hotspots.

[0004] Existing technologies mostly rely on the finite element method to build eye models. Although this method can provide high accuracy, there is still room for improvement in personalization. Researchers are beginning to explore how to combine patients' physiological data and use high-throughput computing power to create personalized eye models to better predict the development of ophthalmic diseases, surgical risks, and treatment effects.

[0005] Therefore, developing a personalized eye model establishment method suitable for finite element simulation can effectively improve the accuracy of ophthalmic treatment and the treatment effect of patients, which will have important application value and social significance. Summary of the invention

[0006] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a method for establishing a personalized eyeball model suitable for finite element simulation, which can greatly improve the authenticity and accuracy of the model, thereby improving the predictive accuracy in ophthalmic diagnosis and treatment.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A method for establishing a personalized eyeball model suitable for finite element simulation, comprising:

[0009] Importing the eye OCT image into a three-dimensional modeling software to obtain structural information of the eye OCT image;

[0010] Based on the structural information, an ellipse is drawn with the coordinate origin in the three-dimensional modeling software; the length of the major axis of the ellipse is the length of the equator of the eyeball; the length of the minor axis of the ellipse is twice the distance from the equator of the eyeball to the posterior pole;

[0011] Crop the ellipse using the x- and y-axes to keep the top right quarter of the ellipse;

[0012] The quarter ellipse is offset 1 mm outward to obtain another quarter ellipse, which forms the contour of the posterior sclera at the equator.

[0013] Starting from the posterior pole, draw the first straight line along the negative direction of the x-axis; the length of the first straight line is the axial length; the end point of the axial straight line is the most anterior end of the cornea;

[0014] Starting from the front end of the cornea, draw a second straight line along the x-axis direction; the length of the second straight line is the corneal thickness;

[0015] Scaling the eye OCT image so that the thickness of the front end of the cornea in the eye OCT image is equal to the length of the second straight line, and moving the eye OCT image to a preset position so that the front end of the eye OCT image coincides with the corneal thickness straight line;

[0016] Draw an arc according to the corneal contour in the eye OCT image;

[0017] Use an arc to connect the sclera and cornea; the arc is tangent to the front end of the sclera;

[0018] Draw line segments according to the contour of the trabecular meshwork in the ocular OCT image;

[0019] The trabecular meshwork contour line segment was offset outward by 0.02 mm, and the offset line segment was used as the scleral canal contour to obtain the half contour of the sagittal plane of the eyeball;

[0020] Draw one-half of the contour of the sagittal plane of the eyeball symmetrically along the x-axis to obtain a complete cross section; the complete cross section is used for two-dimensional axisymmetric finite element analysis;

[0021] One-half of the contour of the sagittal plane of the eyeball is rotated 360° around the x-axis to obtain a three-dimensional eyeball model; the three-dimensional eyeball model is used for 3D finite element analysis.

[0022] Preferably, the structural information includes: the geometric shape of the eyeball, the contours of the cornea and sclera, the scleral canal, the structure of the trabecular meshwork and the relative position of the internal structure of the eyeball.

[0023] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0024] The concept of the present invention comes from the continuous demand for personalized eyeball modeling by clinical ophthalmologists, especially the high requirements for details in the diagnosis and treatment process. This method fully takes into account the complex structural characteristics of the eyeball and models it in a parametric way, so that each person's eyeball can be personalized according to its specific shape. The method of the present invention is parameterized based on common clinical ophthalmic examination data, which is easy to obtain and has high accuracy. By introducing details such as the shape of the trabecular meshwork, unequal corneal thickness, and non-standard arc of the sclera, the authenticity and accuracy of the model can be greatly improved, thereby improving the prediction accuracy in ophthalmic diagnosis and treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A flow chart of a method provided by an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of a quarter ellipse provided in an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of scaling the OCT to a suitable size provided by an embodiment of the present invention;

[0029] Figure 4 A schematic diagram of depicting corneal contour provided by an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of connecting the cornea and sclera provided in an embodiment of the present invention;

[0031] Figure 6 A schematic diagram of drawing the trabecular meshwork and Schlemm's canal provided in an embodiment of the present invention;

[0032] Figure 7 A two-dimensional cross-sectional schematic diagram provided for an embodiment of the present invention;

[0033] Figure 8 A schematic diagram of a three-dimensional model provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The purpose of the present invention is to provide a method for establishing a personalized eyeball model suitable for finite element simulation, which can greatly improve the authenticity and accuracy of the model, thereby improving the predictive accuracy in ophthalmic diagnosis and treatment.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Figure 1 A flow chart of a method provided by an embodiment of the present invention, such as Figure 1 As shown, the present invention provides a method for establishing a personalized eyeball model suitable for finite element simulation, comprising:

[0038] Step 100: Importing the eye OCT image into a three-dimensional modeling software to obtain structural information of the eye OCT image;

[0039] Step 200: Based on the structural information, draw an ellipse with the coordinate origin in the three-dimensional modeling software; the length of the major axis of the ellipse is the length of the equator of the eyeball; the length of the minor axis of the ellipse is twice the distance from the equator of the eyeball to the posterior pole;

[0040] Step 300: crop the ellipse using the x-axis and y-axis to retain the upper right quarter of the ellipse;

[0041] Step 400: offset the quarter ellipse outward by 1 mm to obtain another quarter ellipse to form the equatorial posterior scleral contour;

[0042] Step 500: Starting from the posterior pole, draw a first straight line along the negative direction of the x-axis; the length of the first straight line is the axial length of the eye; the endpoint of the axial straight line is the front end of the cornea; illustratively, the length of this straight line is the axial length, that is, the distance from the cornea to the posterior pole of the eyeball.

[0043] Step 600: Starting from the front end of the cornea, draw a second straight line along the x-axis direction; the length of the second straight line is the corneal thickness;

[0044] Step 700: scaling the eye OCT image so that the thickness of the front end of the cornea in the eye OCT image is equal to the length of the second straight line, and moving the eye OCT image to a preset position so that the front end of the eye OCT image coincides with the corneal thickness straight line;

[0045] Step 800: Draw an arc according to the corneal contour in the eye OCT image;

[0046] Step 900: Use an arc to connect the sclera and cornea; the arc is tangent to the front end of the sclera;

[0047] Step 1000: drawing line segments according to the contour of the trabecular meshwork in the eye OCT image;

[0048] Step 1100: offset the trabecular meshwork contour line segment outward by 0.02 mm, and use the offset line segment as the scleral canal contour to obtain a half contour of the sagittal plane of the eyeball;

[0049] Step 1200: Draw the half contour of the sagittal plane of the eyeball symmetrically along the x-axis to obtain a complete cross section; the complete cross section is used for two-dimensional axisymmetric finite element analysis;

[0050] Step 1300: Rotate the half contour of the sagittal plane of the eyeball 360° around the x-axis to obtain a three-dimensional eyeball model; the three-dimensional eyeball model is used for 3D finite element analysis.

[0051] As an optional implementation mode, the implementation process of this embodiment is as follows:

[0052] Step 1: Import the optical coherence tomography (OCT) image of the eye into the 3D modeling software.

[0053] Step 2: Draw an ellipse with the coordinate origin as the center. The major and minor axes of the ellipse are 23.324mm and 22.168mm.

[0054] Step 3: Use the x-axis and y-axis to crop the ellipse, leaving only the upper right quarter of the ellipse.

[0055] Step 4: Take the quarter ellipse drawn in step 3 and offset it 1mm outward to obtain another quarter ellipse to form the equatorial posterior scleral contour, see Figure 2 .

[0056] Step 5: Starting from the posterior pole, draw a straight line along the negative direction of the x-axis. The length of the straight line is 27.168 mm. The end point of the axial line is the front end of the cornea.

[0057] Step 6: Starting from the front end of the cornea, draw a straight line along the x-axis with a length of 0.576 mm.

[0058] Step 7: Scale the eye OCT image so that the thickness of the corneal front end of the OCT image is equal to the length of the straight line drawn in step 6, and move the eye OCT image to a suitable position so that the front end of the eye OCT image coincides with the corneal thickness straight line, see Figure 3 .

[0059] Step 8: Draw an arc according to the corneal contour in the eye OCT image, see Figure 4 .

[0060] Step 9: Use an arc to connect the sclera and cornea. The arc should be tangent to the sclera end. Figure 5 . Demonstratively, after this step, the preliminary half-contour of the sagittal plane of the eyeball has been formed.

[0061] Step 10: Draw a line segment according to the contour of the trabecular meshwork in the ocular OCT image.

[0062] Step 11: Offset the trabecular meshwork contour line segment outward by 0.02 mm as the Schlemm canal contour, see Figure 6 .

[0063] Step 12: The half-surface of the sagittal plane of the eyeball has been completed. It is symmetrical along the x-axis to obtain a complete cross section, which can be used for two-dimensional axisymmetric finite element analysis. Figure 7 .

[0064] Step 13: Rotate the half of the eyeball's sagittal plane contour 360° around the x-axis to obtain a three-dimensional eyeball model suitable for 3D finite element analysis, see Figure 8 .

[0065] The beneficial effects of the present invention are as follows:

[0066] (1) Personalized modeling: The present invention can model according to the shape of each person's eyeball, solving the problem in the prior art that the "standardized model" cannot adapt to individual differences.

[0067] (2) Convenient parameter acquisition: The present invention can conveniently obtain the parameters required for eyeball modeling through routine clinical ophthalmological examination, avoiding expensive equipment and complex image data acquisition process.

[0068] (3) Higher modeling accuracy: By introducing details such as the shape of the trabecular meshwork, unequal corneal thickness, and non-standard arc of the sclera, the present invention makes the model more realistic and can accurately reflect the complex structure of the eyeball, thereby improving the diagnosis and treatment effect. It has significant advantages in the fields of glaucoma, corneal transplantation, and refractive surgery.

[0069] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0070] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for establishing a personalized eyeball model suitable for finite element simulation, characterized in that: include: Importing the eye OCT image into a three-dimensional modeling software to obtain structural information of the eye OCT image; Based on the structural information, an ellipse is drawn with the coordinate origin in the three-dimensional modeling software; the length of the major axis of the ellipse is the length of the equatorial part of the eyeball; The length of the minor axis of the ellipse is twice the distance from the equator to the posterior pole of the eyeball; Crop the ellipse using the x- and y-axes to keep the top right quarter of the ellipse; The quarter ellipse is offset 1 mm outward to obtain another quarter ellipse, which forms the contour of the posterior sclera at the equator. Starting from the posterior pole, draw the first straight line along the negative direction of the x-axis; the length of the first straight line is the axial length; the end point of the axial straight line is the most anterior end of the cornea; Starting from the front end of the cornea, draw a second straight line along the x-axis direction; the length of the second straight line is the corneal thickness; Scaling the eye OCT image so that the thickness of the front end of the cornea in the eye OCT image is equal to the length of the second straight line, and moving the eye OCT image to a preset position so that the front end of the eye OCT image coincides with the corneal thickness straight line; Draw an arc according to the corneal contour in the eye OCT image; Use an arc to connect the sclera to the cornea; The arc is tangent to the anterior end of the sclera; Draw line segments according to the contour of the trabecular meshwork in the ocular OCT image; The trabecular meshwork contour line segment was offset outward by 0.02 mm, and the offset line segment was used as the scleral canal contour to obtain the half contour of the sagittal plane of the eyeball; Draw one-half of the contour of the sagittal plane of the eyeball symmetrically along the x-axis to obtain a complete cross section; the complete cross section is used for two-dimensional axisymmetric finite element analysis; One-half of the contour of the sagittal plane of the eyeball is rotated 360° around the x-axis to obtain a three-dimensional eyeball model; the three-dimensional eyeball model is used for 3D finite element analysis.

2. The method for establishing a personalized eyeball model suitable for finite element simulation according to claim 1, characterized in that: The structural information includes: the geometric shape of the eyeball, the contours of the cornea and sclera, the scleral canal, the structure of the trabecular meshwork and the relative positions of the internal structures of the eyeball.

Images