Rapid secondary adjustment system, method and equipment for optical axis center

Abstract

The invention belongs to the field of laser processing, and discloses a visual axis center rapid secondary adjustment system, method and equipment. The system comprises a data input module; a data generation module; the data processing module comprises a surface type equation construction module which is used for constructing a cutting track surface type equation of each cutting step of the micro lens according to the shape parameters of the micro lens; the coordinate transformation module is used for rotating and changing the analytic expression of each cutting surface; the two-dimensional cutting parameter generation module is used for calculating a three-dimensional analytic expression of each cutting step and an intersection line contour of a cutting plane as a two-dimensional cutting track analytic expression; the light emitting range constraint module is used for obtaining light emitting information on each cutting track; and the control signal compiling module is used for compiling the cutting signal. The data processing module of the system carries out resolution, sampling and constraint through the curved surface expression of the microlens and the contour expression of the microlens on the cutting plane, compensates the off-axis motion of the eyeball, and improves the precision and effect of automatic alignment of the center of the visual axis.

Description

Technical Field

[0001] This invention belongs to the field of laser processing, and more specifically, relates to a system, method and device for rapid secondary adjustment of the visual axis center. Background Technology

[0002] Before some femtosecond laser systems can process pre-set microlenses within the cornea, manual alignment of the contact lens with the cornea using negative pressure is required, along with aligning the laser's optical axis with the visual axis. Traditional manual alignment methods have significant limitations in positioning accuracy; if the laser's optical axis and visual axis fail to align precisely, the operator must repeatedly adjust. This process not only results in low alignment accuracy but also exacerbates corneal inflammation due to prolonged operation time, ultimately affecting the final processing quality.

[0003] Currently, commonly used methods for aligning the optical axis with machining centers mainly rely on manual alignment of the negative pressure ring using methods such as coaxial camera imaging. However, the equipment itself lacks the technical capability to automatically compensate for positional deviations—especially the angular deviations between the optical axis and the optical axis caused by curved negative pressure rings. Therefore, developing a device capable of automatically aligning the optical axis and the optical axis is a significant and urgent practical need. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a rapid secondary adjustment system, method, and device for the visual axis center. The data processing module in this system re-solves, samples, and constrains the surface expression of the microlens and its contour expression on the cutting plane to compensate for the off-axis movement of the eyeball, thereby improving the accuracy and effectiveness of automatic alignment of the visual axis center. This solves the technical problem of insufficient accuracy and efficiency in aligning the optical axis with the visual axis center in existing technologies.

[0005] To achieve the objective of this invention, in a first aspect, a method for rapid secondary adjustment of the visual axis center is provided, characterized by comprising the following steps: S1: Obtain microlens fabrication parameters and corneal topography; S2: Generate the microlens processing parameters into microlens shape parameters, and calculate the deflection angle of the visual axis relative to the processing center based on the corneal topography; S3: Based on the shape characteristics of the upper surface, lower surface, side cut, and small incision of the microlens, construct the cutting trajectory surface equation of the upper surface, lower surface, side cut, and small incision of the microlens according to the shape parameters of the microlens. S4: Rotate the analytical expressions of the upper surface, lower surface, lateral cut, and small incision of the microlens around the center of the corneal sphere along the x-axis, y-axis, and z-axis to obtain the three-dimensional analytical expressions of the upper surface, lower surface, lateral cut, and small incision of the microlens after rotation; wherein, the two axes perpendicular to each other of the elliptical trajectory of the lower surface of the microlens are the x-axis and y-axis, and the direction perpendicular to the x-axis and y-axis is the z-axis; S6: Construct several cutting planes parallel to the XOY plane with different z-axis positions, calculate the three-dimensional analytical expressions of the upper surface, lower surface, side cut, and small incision of the microlens and the intersection contours of the cutting planes, and use these intersection contours as the two-dimensional cutting trajectory analytical expressions of the upper surface, lower surface, side cut, and small incision of the microlens. S7: By controlling the cutting trajectory of the upper surface, lower surface, side cut, and small cut of the microlens through geometric constraints, the light output information on each cutting trajectory is obtained; S8: Combine the cutting parameters of the upper surface, lower surface, side cut, and small incision of the microlens obtained in step S6 with the light-emitting point information obtained in step S7 to compile a cutting signal.

[0006] In a second aspect of the invention, a rapid secondary adjustment system for the visual axis center is provided, comprising: The data input module is used to acquire microlens processing parameters and corneal topography. The data generation module is used to generate microlens shape parameters from the microlens processing parameters, and to calculate the deflection angle of the visual axis relative to the processing center based on the corneal topography. The data processing module includes: a surface equation construction module, used to construct the surface equations of the cutting trajectories of the microlens's upper surface, lower surface, lateral cut, and small incision based on the shape characteristics of the microlens's upper surface, lower surface, lateral cut, and small incision; a coordinate transformation module, used to rotate the analytical expressions of the cutting surfaces of the microlens's upper surface, lower surface, lateral cut, and small incision around the center of the corneal sphere, along the x-axis, y-axis, and z-axis, to obtain the rotated three-dimensional analytical expressions of the microlens's upper surface, lower surface, lateral cut, and small incision; and a two-dimensional cutting parameter generation module, used to construct several cutting planes parallel to the XOY plane with unequal z-axis positions, and calculate the surface equations of the microlens's upper surface, lower surface, lateral cut, and small incision respectively. The three-dimensional analytical expressions of the cut and small incisions and the intersection contours of the cutting planes are used as the two-dimensional analytical expressions of the cutting trajectories of the upper surface, lower surface, side cut, and small incisions of the microlens. The light emission range constraint module is used to control the cutting trajectories of the upper surface, lower surface, side cut, and small incisions of the microlens through geometric constraints to obtain the light emission information on each cutting trajectory. The control signal compilation module is used to compile the cutting parameters of the upper surface, lower surface, side cut, and small incisions of the microlens obtained in the two-dimensional cutting parameter generation module into the light emission point information obtained in the light emission range constraint module and compile them into a cutting signal. Here, the two mutually perpendicular axes of the elliptical trajectory of the lower surface of the microlens are denoted as the x-axis and y-axis, and the direction perpendicular to the x-axis and y-axis is denoted as the z-axis.

[0007] Preferably, the system further includes: a microscopic imaging module and / or a data pre-storage module, connected to the data input module; the microscopic imaging module is used to capture corneal topography, and the data pre-storage module is used to store pre-input microlens processing parameters and corneal topography.

[0008] Preferably, the microlens shape parameters include the upper surface shape parameters, lower surface shape parameters, side-cut shape parameters, and small-cut shape parameters of the microlens; the surface equation construction module constructs the analytical expression of the upper surface of the microlens based on the spherical equation for the upper surface shape parameters, constructs the analytical expression of the lower surface of the microlens based on the ellipsoidal equation for the lower surface shape parameters, and constructs the analytical expression of each conical surface in the side-cut and small-cut of the microlens based on the conical equation for the side-cut and small-cut shape parameters, respectively.

[0009] Preferably, the surface shape equation construction module constructs the analytical expression of the upper surface of the microlens based on the spherical equation by substituting the spherical curvature radius of the upper surface of the microlens into the standard spherical equation to construct the analytical expression of the shape of the upper surface; The surface shape equation construction module constructs an analytical expression for the lower surface of the microlens based on the ellipsoid equation using the shape parameters of the lower surface of the microlens. This includes: determining the radius of curvature and asphericity of the XOZ section and the radius of curvature and asphericity of the YOZ section of the lower surface of the microlens, and restricting their proportional relationship to ensure that the lower surface of the microlens is an ellipsoid; then substituting the radius of curvature and asphericity of the XOZ section and the YOZ section of the lower surface of the microlens, and their relationship, into the quadratic surface equation to obtain the analytical expression for the shape of the lower surface. The surface equation construction module constructs analytical expressions for each conical surface in the microlens based on the conical surface equation, including substituting the slope of the generatrix of the conical surface corresponding to the microlens' side cut and small cut into the conical surface analytical equation to obtain the analytical expression for each conical surface in the side cut and small cut.

[0010] Preferably, the three-dimensional analytical expressions of the upper surface, lower surface, side cut, and small incision of the rotated microlens obtained by the coordinate transformation module are represented by a rotation matrix or quaternion calculated using Euler angles.

[0011] Preferably, in the two-dimensional cutting parameter generation module, the three-dimensional analytical expressions of the upper surface, lower surface, side cut, and small incision of the microlens and the intersection contours of the cutting plane are calculated respectively. These intersection contours are then used as the two-dimensional cutting trajectory analytical expressions of the upper surface, lower surface, side cut, and small incision of the microlens. This includes: calculating the two-dimensional cutting trajectory analytical expression of the intersection contour of the upper surface as a circle based on the spherical surface of the upper surface of the microlens and the cutting plane; substituting the z-coordinate of the cutting plane into the equation of the ellipsoid of the lower surface of the microlens to calculate the two-dimensional cutting trajectory analytical expression of the intersection contour of the lower surface as an ellipse; and substituting the z-coordinate of the cutting plane into the equations of the conical surfaces of the side cut and the small incision of the microlens respectively to calculate the two-dimensional cutting trajectory analytical expressions of the intersection contour of the side cut as an ellipse and the intersection contour of the small incision as an ellipse.

[0012] Preferably, in the light emission range constraint module, the light emission point of the two-dimensional cutting trajectory on the upper surface is constrained on the intersecting circular contour of the upper surface sphere and the cutting plane, and located above the bottom surface of the upper surface; the light emission point of the two-dimensional cutting trajectory on the lower surface is constrained above the bottom surface of the lower surface, and located within the first segment of the laterally cut conical surface; the light emission point of the two-dimensional cutting trajectory on the first segment of the laterally cut conical surface is constrained between the bottom and top surfaces of the conical surface; the light emission point of the two-dimensional cutting trajectory on the second segment of the laterally cut conical surface is constrained between the bottom and top surfaces of the conical surface; the light emission point of the two-dimensional cutting trajectory on the small cut is constrained between the bottom and top surfaces of the conical surface corresponding to the small cut; wherein the top surface of the first segment of the laterally cut conical surface coincides with the bottom surface of the second segment of the laterally cut conical surface.

[0013] In a third aspect of the present invention, a device for rapid secondary adjustment of visual axis center is provided, comprising: a rapid secondary adjustment system for visual axis center as described in any of the preceding claims and a cutting module; the cutting module includes a control module, an execution module, an optical module and a three-dimensional scanning module; The control module is used to convert the cutting signal generated by the rapid secondary adjustment system of the visual axis center into a signal that drives the movement of the three-dimensional scanning module and a digital pulse signal that drives the execution module, and to adjust the signal that drives the movement of the three-dimensional scanning module and the digital pulse signal that drives the execution module to achieve cutting in multiple areas within the cutting trajectory of the upper surface, lower surface, side cut, and small incision of the microlens; The execution module is connected to the control module and is used to output a femtosecond laser according to the digital pulse signal output by the control module to perform microlens cutting after adjustment by the visual axis center rapid secondary adjustment system. The three-dimensional scanning module is connected to the control module and the execution module, and is used to control the femtosecond laser focus output by the execution module to move freely in three-dimensional space according to the signal output by the control module. The optical module is connected to the execution module and is used to focus the femtosecond laser beam emitted by the execution module onto the cornea to be processed.

[0014] In a fourth aspect of the invention, a device for rapid secondary adjustment of the visual axis center is provided, comprising: a storage medium and a processor; the storage medium being used to store instructions; and the processor being used to operate according to the instructions to execute the rapid secondary adjustment method of the visual axis center as described in any of the preceding claims.

[0015] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages: The proposed system for rapid secondary adjustment of the visual axis center in this invention compensates for the off-axis movement of the eyeball by resolving, sampling, and constraining the surface expression of the laser-processed microlens and its contour expression on the cutting plane. This improves the accuracy and effectiveness of automatic alignment of the visual axis center, reduces corneal inflammation, and enhances the processing quality of the microlens.

[0016] This invention avoids the repetition of scanning data by resolving the contour expression of the cutting plane. At the same time, it constrains the set positional relationship of the light-emitting points on the cutting plane, avoiding repeated traversal of the data, which greatly improves the data generation speed. Furthermore, by directly solving the expression, the data accuracy is closer to the design value before adjustment, thereby improving the efficiency of automatic alignment of the view axis center. Compared with the existing secondary adjustment method of machining center, it is faster. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the rapid secondary adjustment system for the visual axis center shown in this invention.

[0018] Figure 2 This is a schematic diagram of the microlens shape parameters of the method shown in this invention.

[0019] Figure 3 This is a schematic diagram illustrating the method of the present invention in locating the light-emitting point on the upper surface of a microlens.

[0020] Figure 4 This is a schematic diagram illustrating the method of the present invention in locating the lower surface of the microlens and the first side-cut light spot.

[0021] Figure 5 This is a schematic diagram illustrating the method of the present invention in finding the light-emitting point of the side cut and small incision.

[0022] Figure 6 The method shown in this invention adjusts the shape of the microlens before and after.

[0023] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-Visual axis, 2-Optical axis, 3-Central thickness of microlens, 4-Cutting trajectory of each step, 5-Target corneal vertex, 6-Upper surface, 6a-Radius of curvature of upper surface spherical surface, 6b-Radius of cutting range of upper surface, 6c-Intersecting circular profile of upper surface spherical surface and cutting plane, 6d-Bottom of upper surface, 7-Lower surface, 7a-Center of lower surface ellipsoid, 7b-Radius of lower surface optical zone or radius of the circular directrix of the cone intersecting the lower surface in the lateral biconical surface, 7c-Cutting thickness of lower surface, 7d-Distance from the center of lower surface ellipsoid to the bottom of lower surface cutting, 7e-Bottom of lower surface, 7f-Ellipsoid of lower surface, 7h-Axis of rotational symmetry, 7k-Center of light-emitting region, 7l-A parallel plane parallel to the bottom of lower surface 7e through the light-emitting region, 7m-Parallel plane 8 - The cross-sectional circle obtained by the intersection of surface 7l and the first conical surface 8d; 8 - Lateral section; 8a - The radius of the circular directrix of the conical surface intersecting the upper surface in the lateral double conical surface; 8b - The slope of the generatrix of the conical surface intersecting the lower surface in the lateral double conical surface; 8c - The slope of the generatrix of the conical surface intersecting the upper surface in the lateral double conical surface; 8d - The conical surface intersecting the lower surface (i.e., the first conical surface); 8e - The conical surface intersecting the upper surface (i.e., the second conical surface); 8g - The bottom surface of the conical surface; 8h - The top surface of the conical surface; 8i - The radius of the top surface of the conical surface; 9 - The small incision; 9a - The slope of the generatrix of the small incision; 9b - The depth of the incision; 9c - The radius of the top surface of the small incision conical surface; 9d - A point on the conical surface; 9f - The angle between the perpendicular line and the x-axis of the coordinate system of the small incision conical surface; 10 - The spherical surface of the target cornea; 11 - The microlens. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0025] This invention provides a rapid secondary adjustment system, method, and device for the visual axis center. By resolving, sampling, and constraining the surface expression of the laser-processed microlens and its contour expression on the cutting plane, the three-dimensional spatial position and orientation of the microlens to be processed are matched with the visual axis, thereby achieving rapid alignment between the processed microlens and the visual axis center.

[0026] To achieve the above objectives, according to one aspect of the present invention, a rapid secondary adjustment system for the visual axis center is provided, such as... Figure 1 As shown, it includes the following modules: The data input module is used to acquire microlens processing parameters and corneal topography.

[0027] The microlens fabrication parameters are obtained either by receiving manually input data from the user or by retrieving them from pre-stored microlens fabrication parameters. These microlens fabrication parameters, combined with... Figures 2-6 This includes parameters used to determine the shape of the microlens, such as the microlens' corrected refractive power, corrected astigmatism, optical zone radius, central thickness of the microlens, cutting radius of the microlens' upper surface, and the slope and depth of the small incision. The rapid secondary adjustment system for the visual axis center is used for rapid alignment of the processing center in femtosecond LASIK surgery. The microlens fabrication process involves cutting the upper surface, lower surface, lateral incision, and small incision of the microlens, and the definitions of the upper surface, lower surface, lateral incision, and small incision satisfy the definitions of each cutting step in the rapid alignment technique for the processing center in femtosecond LASIK surgery.

[0028] Corneal topography is acquired by receiving corneal topography images captured by a microscope camera or retrieving them from a pre-stored corneal topography database. The corneal topography contains corneal watermark information, pupil shape and position information, iris shape and position information, and other data used to calculate the deflection angle of the visual axis relative to the processing optical axis of the device.

[0029] Preferably, the system further includes a microscopic imaging module connected to the data input module, used to capture corneal topography of the visual axis to be processed and to record and monitor the processing. For example, when the corneal topography is acquired by receiving corneal topography images from a microscope camera, the microscopic imaging module is a corneal topography instrument that captures the corneal topography. And / or the system includes a data pre-storage module connected to the data input module, used to store pre-acquired microlens processing parameters and corneal topography data.

[0030] The data generation module is used to generate microlens shape parameters from microlens processing parameters, and to calculate the deflection angle of the visual axis relative to the processing center based on the corneal topography.

[0031] Microlens shape parameters include the shape parameters of the upper surface, lower surface, side cut, and small incision of the microlens. Specifically, this is combined with... Figure 2As shown, the surface includes: The upper surface 6 is typically spherical, determined by the shape of the contact lens to which it will connect with the cornea during processing and the operator's experience. Its parameters include the upper surface spherical curvature radius 6a and the upper surface cutting radius 6b. The lower surface 7 is typically an ellipsoid, with parameters including the lengths of the three semi-axes of the ellipsoid along the x, y, and z axes, the lower surface cutting thickness 7c, the lower surface optical zone radius 7b, and the distance 7d from the center 7a of the lower surface ellipsoid to the bottom of the lower surface cutting. The lengths of the three semi-axes of the ellipsoid along the x, y, and z axes are calculated using the Munnerlyn formula from the microlens processing parameters of refractive power, astigmatism, corneal curvature radius, and contact lens curvature radius. The lateral cut 8 is typically a biconical surface, determined by the lower surface normal direction and the operator's experience. Its parameters include the radii 7b and 8a of the two circular directrixes of the lateral cut biconical surface and the slopes 8b and 8c of the two generatrices. The small incision 9 is typically a single conical surface, and its parameters include the radius 6b of the circular guideline of the small incision (usually equal to the cutting radius of the upper surface), determined by the normal direction of the upper surface and the operator's experience, the slope 9a of the generatrix of the small incision, and the incision depth 9b. The microlens shape parameters also include the central thickness 3 of the microlens.

[0032] The deflection angle is the deflection angle data of the line of sight 1 relative to the processing optical axis 2 of the equipment, including the angle α of the line of sight around the x-axis, the angle β of the line of sight around the y-axis, and the deflection angle γ around the z-axis, which is used to compensate for the deflection angle within 2°.

[0033] The data processing module includes: a surface equation construction module, used to construct the surface equation of the cutting trajectory for each cutting step based on the shape characteristics of the microlens' upper surface, lower surface, lateral cut, and small incision; a coordinate transformation module, used to rotate the analytical expressions of each cutting surface around the center of the corneal upper surface sphere, along the x-axis, y-axis, and z-axis, to obtain the rotated analytical expressions of each cutting step; a two-dimensional cutting parameter generation module, used to construct several cutting planes parallel to the XOY plane with unequal z-axis positions for each cutting step of the microlens, calculate the intersection contours of the three-dimensional analytical expressions of each cutting step and the cutting planes, and use these intersection contours as the two-dimensional cutting trajectory analytical expressions of each cutting step; a light emission point constraint module, used to control the cutting trajectory of each step through geometric constraints, and obtain the light emission information on each cutting trajectory; and a control signal compilation module, used to compile the cutting parameters of each cutting step obtained in the two-dimensional cutting parameter generation module and the light emission point information obtained in the light emission range constraint module into a cutting signal. Here, the two axes perpendicular to each other on the elliptical trajectory of the lower surface of the microlens are the x-axis and y-axis, and the direction perpendicular to the x-axis and y-axis is the z-axis.

[0034] The surface equation construction module is used to construct the surface equations for the scanning trajectories of the upper surface, lower surface, side cut, and small incision of the microlens. Preferably, the surface equation construction module constructs the analytical expression for the upper surface of the microlens based on the spherical equation, the analytical expression for the lower surface of the microlens based on the ellipsoidal equation, and the analytical expressions for each conical surface in the side cut and small incision based on the conical equation, respectively. Specifically: In this invention, the surface shape equation construction module constructs an analytical expression for the shape of the upper surface by substituting the radius of curvature of the upper surface of the microlens into the standard spherical equation; it determines the radius of curvature and asphericity of the XOZ section and the YOZ section of the lower surface of the microlens, and restricts their proportional relationship to ensure that the lower surface of the microlens is an ellipsoid; then it substitutes the radius of curvature and asphericity of the XOZ section and the YOZ section of the lower surface of the microlens, and their relationship, into the quadratic surface equation to obtain an analytical expression for the shape of the lower surface; and it substitutes the slopes of the generatrices of the conical surfaces corresponding to the lateral cut and the small cut of the microlens into the analytical equation of the conical surface to obtain the analytical expression for each conical surface in the lateral cut and the small cut.

[0035] It should be noted that the two mutually perpendicular axes of the elliptical trajectory on the lower surface of the microlens are the x-axis and y-axis, respectively, and the direction perpendicular to the x-axis and y-axis is the z-axis. The x-axis can be either the major or minor axis of the ellipse, and the corresponding y-axis is another axis on the XOY plane perpendicular to the x-axis. In the surface equation construction module, based on the interchangeable definitions of the x-axis and y-axis, the XOZ section and the YOZ section can also be interchanged.

[0036] The specific execution steps for the surface equation construction module are as follows: First, determine the radius of curvature of the upper spherical surface and constrain its proportional relationship to ensure that the lower surface is a standard sphere. Then, determine the radius of curvature of the XOZ section of the lower surface. Rx asphericity Qx radius of curvature of the YOZ section Ry asphericity Qy And restrict their proportional relationship to ensure that the lower surface is an ellipsoid.

[0037] The upper surface 6 is usually a sphere with a radius of curvature of 20 mm.

[0038] The lower surface 7 is typically the radius of curvature of a given XOZ section. Rx asphericity Qx radius of curvature of the YOZ section Ry asphericity Qy The hyperquadratic surface.

[0039] in Rx , Ry The ratio, Qx+1 , Qy+1 The ratio must be equal to the same proportionality coefficient to ensure that the lower surface is a standard ellipsoid.

[0040] Then, the cutting trajectory surface equations for each cutting step are used to construct the analytical equations for each cutting surface.

[0041] (1) For the upper surface: Substitute the radius of curvature of the upper spherical surface into the standard spherical equation to construct the analytical expression of the shape of the upper surface. The upper surface 6 is a sphere, and its analytical equation is as follows: .

[0042] in Rh Let be the radius of curvature of the upper spherical surface, which can be expressed in matrix form as: .

[0043] (2) For the lower surface: the radius of curvature of the XOZ section of the lower surface. Rx Asphericity Qx radius of curvature of the YOZ section Ry asphericity Qy Substituting its relationship into the Biconic equation (i.e., through...) ), and then use of By shifting the z-axis by a distance c, we can obtain the analytical expression for the shape of the lower surface ellipsoid.

[0044] The analytical expression for the shape of the lower surface ellipsoid can be written in the standard equation form of the ellipsoid as follows: ; Represented in matrix form as follows: .

[0045] (3) For lateral cuts and small cuts: The analytical expression for each conical surface is obtained based on the shape parameters of the lateral cuts and small cuts. Both lateral cut 8 and small cut 9 are composed of conical surfaces, and the analytical equation of each segment of the conical surface is as follows: ; in k Let be the slope of the generatrix of the cone.

[0046] The above equations can be expressed in matrix form: .

[0047] The coordinate transformation module is used to rotate the analytical expressions of each cutting surface around the center of the sphere on the upper surface of the cornea, and change the coordinates along the x-axis, y-axis, and z-axis by the deflection angles, to obtain the analytical expressions of each cutting step after rotation.

[0048] Given that the deflection angle of the view axis about the x-axis is α, about the y-axis is β, and about the z-axis is γ, the analytical expressions for each cutting step after the rotation transformation can be represented by rotation matrices or quaternions calculated using Euler angles. The specific rotation matrices calculated using Euler angles for the rotation transformation are as follows: Rotation matrix about the x-axis. Rotation matrix around the y-axis Rotation matrix about the z-axis .

[0049] (1) The upper surface 6 is a sphere, and its analytical expression after rotation around the center of the sphere is the same as before rotation.

[0050] (2) The lower surface 7 is an ellipsoid, and the rotation matrix is ​​centered at the center of the ellipsoid 7a. Furthermore, it is easy to determine the principal direction of the ellipsoid after rotation. Let S be the direction vectors of the principal directions after rotation. Multiplying the rotation matrix or quaternion with the characteristic matrix of the standard ellipsoid yields the characteristic matrix S of the rotated ellipsoid.

[0051] Therefore, the analytical expression of the rotated ellipsoid is as follows: ; (3) Both the lateral cut 8 and the small cut 9 are composed of conical surfaces. For each of the conical surfaces that make up them, a rotation matrix is ​​formed about the x, y, and z axes with rotation angles α, β, and γ around the vertex of the conical surface. Multiplying the rotation matrix or quaternion with the characteristic matrix of the cone surface yields the characteristic matrix of each cone surface after rotation. The analytical expression for the cone surface is:

[0052] in k Let be the slope of the generatrix of the cone. Rot Let be the rotation matrix of the cone.

[0053] The 2D cutting parameter generation module is used to construct several cutting planes parallel to the XOY plane with different z-axis positions for each cutting step of the microlens. It calculates the 3D analytical expression for each cutting step and the intersection profile of the cutting planes, using these intersection profiles as the 2D cutting trajectory analytical expression. Specifically: based on the intersection profile of the upper spherical surface of the microlens and the cutting plane, a 2D cutting trajectory analytical expression with a circular intersection profile is obtained; based on the intersection profile of the upper spherical surface of the microlens and the cutting plane, a 2D cutting trajectory analytical expression with a circular intersection profile is obtained; substituting the z-coordinate of the cutting plane into the equation of the lower ellipsoidal surface of the microlens, a 2D cutting trajectory analytical expression with an elliptical intersection profile is obtained; substituting the z-coordinate of the cutting plane into the equations of the lateral cut and the small incision cone surface of the microlens, respectively, a 2D cutting trajectory analytical expression with an elliptical intersection profile is obtained for the lateral cut and the small incision, respectively.

[0054] The specific execution steps of the preferred method for generating 2D cutting parameters are as follows: (1) The upper surface 6 is a sphere, and the outline of its intersection with the cutting plane is a circle, with the center of the circle passing through the z-axis.

[0055] (2) The lower surface 7 is an ellipsoid, and the outline of its intersection with the cutting plane is a general ellipse.

[0056] Intersecting the transformed ellipsoid equation with the cutting plane yields the equation of the ellipse for the cutting trajectory on a single cutting plane: ; in These are the three principal directions of the rotated ellipsoid. a , b , c These are the semi-axis lengths of the ellipsoid along its principal directions; z i The z-coordinate of the cutting plane; S is the characteristic matrix of the ellipsoid.

[0057] We can calculate the major axis of the elliptical cutting trajectory of the lower surface using the elliptical trajectory equation. short axis Rotation angle 1. Coordinates of the center of the ellipse [ , ].

[0058] Finally, we can obtain the two-dimensional elliptical trajectory expressions on the different cutting planes of each cutting step that make up the microlens.

[0059] (3) Both the side cut 8 and the small cut 9 are composed of conical surfaces, and the outline of their intersection with the cutting plane is a general ellipse.

[0060] Intersecting the equation of the cone surface after rotational transformation with the cutting plane yields the equation of the ellipse of the cutting trajectory on a single cutting plane: ; in Rot For rotation matrix, k Let be the slope of the generatrix of the cone. z i The z-coordinate of the cutting plane, This is the characteristic matrix of the cone surface.

[0061] Using the elliptical trajectory equation, we can calculate the major axis of the elliptical cutting trajectory for side cuts or small cuts. short axis Rotation angle 1. Coordinates of the center of the ellipse [ , ].

[0062] Finally, we can obtain the two-dimensional elliptical trajectory expressions on the different cutting planes of the various cutting steps that make up the microlens. The light emission point constraint module is used to control the cutting trajectory 4 of each step through geometric constraints, and obtain the light emission information on each cutting trajectory, including the light emission point and the light emission range. (1) For the upper surface, such as Figure 3 As shown, the light-emitting point must satisfy the following conditions: it is located on the intersecting circular contour 6c of the upper surface 6 sphere and the cutting plane, and is above the bottom surface 6d of the upper surface.

[0063] (2) For the lower surface, such as Figure 4 As shown, the light-emitting point must meet the following requirements: it must be located above the bottom surface 7e of the lower surface and within the first conical surface 8d of the lateral section 8.

[0064] (3) For the first segment of the laterally cut cone, the light-emitting point must meet the following requirements: 1. It is located between the bottom surface 8g and the top surface 8h of the cone, where the radius of the bottom surface is 7b (i.e., the radius of the optical area of ​​the lower surface or the radius of the circular guideline of the cone intersecting the lower surface in the laterally cut double cone), and the radius of the top surface is 8a (i.e., the radius of the circular guideline of the cone intersecting the upper surface in the laterally cut double cone); 2. It intersects with the light-emitting range of the lower surface.

[0065] (4) For the second conical section of the lateral section, as follows Figure 5 As shown, the light-emitting point must be located between the bottom surface 8g and the top surface 8h of the cone. The top surface of the first laterally cut cone and the bottom surface of the second laterally cut cone coincide, forming a double cone.

[0066] (5) For small incisions, such as Figure 5As shown, the light-emitting point must satisfy the following conditions: 1. It is located between the bottom surface 8g and the top surface 8h of the cone; 2. A perpendicular line is drawn from a point 9d on the cone to the axis of rotational symmetry 7h, and the angle 9f between this perpendicular line and the x-axis of the small-cut cone's own coordinate system is within the range of the small-cut angle.

[0067] The control signal compilation module is used to compile the cutting parameters of the cutting trajectory calculated in step S4 and the light emission point information obtained in step S5 into cutting signals.

[0068] The cutting parameters of the cutting trajectory in each step include the major axis of the current cutting trajectory. a short axis b ,angle θ The center point coordinates are [x0, y0], and the location of the light-emitting point is [x0, y0]. st Location of the light-off point ed The angular coordinates of each scanned data point in the polar coordinate system According to the formula: ; Or the major axis of the current cutting trajectory short axis ,angle The center point coordinates are [x0, y0], and the location of the light-emitting point is [x0, y0]. st Location of the light-off point ed The angular coordinates of each scanned data point in the polar coordinate system According to the formula: .

[0069] For example, the code is compiled into actual cutting signals. The cutting signals for the X and Y axes are analog voltage signals, while the laser control signals, Z-axis stepper motor commutation and drive signals are digital pulse signals.

[0070] According to another aspect of the present invention, a method for rapid secondary adjustment of the visual axis center is provided, the method comprising the following steps: S1: Obtain microlens fabrication parameters and corneal topography; S2: Generate microlens processing parameters into microlens shape parameters, and calculate the deflection angle of the visual axis relative to the processing center based on the corneal topography; S3: Construct the cutting trajectory surface equation for each cutting step based on the shape characteristics of the upper surface, lower surface, side cut, and small incision of the microlens. S4: Rotate the analytical expressions of each cutting surface around the center of the corneal sphere along the x-axis, y-axis and z-axis to obtain the rotated analytical expressions of each cutting step; wherein, the two axes perpendicular to each other of the elliptical trajectory of the lower surface of the microlens are the x-axis and y-axis, and the direction perpendicular to the x-axis and y-axis is the z-axis; S5: For each cutting step of the microlens, construct several cutting planes parallel to the XOY plane with different z-axis positions, calculate the three-dimensional analytical expression of each cutting step and the intersection profile of the cutting plane, and use these intersection profiles as the two-dimensional cutting trajectory analytical expression of each cutting step. S5: Control the cutting trajectory of each step through geometric constraints to obtain the light output information on each cutting trajectory; S6: Combine the cutting parameters obtained in step S4 with the light-emitting point information obtained in step S5 to compile a cutting signal.

[0071] In this invention, the rapid secondary adjustment system for the visual axis center is applied to the rapid alignment of the processing center during femtosecond LASIK surgery. All steps of the rapid secondary adjustment method for the visual axis center are implemented by a computer or similar device, and its preferred scheme is consistent with the preferred scheme executed by each module in the aforementioned rapid secondary adjustment system for the visual axis center, and will not be repeated here.

[0072] The automatic alignment device for the visual axis center provided in the third aspect of this application includes the aforementioned rapid secondary adjustment system for the visual axis center and a cutting module; the cutting module includes a control module, an execution module, an optical module, and a three-dimensional scanning module; The control module is used to convert the cutting signal generated by the rapid secondary adjustment system of the vision axis center into a signal that drives the movement of the three-dimensional scanning module and a digital pulse signal that drives the execution module, as well as to adjust the signal that drives the movement of the three-dimensional scanning module and the digital pulse signal that drives the execution module, so as to realize the cutting of multiple regions within a single-circle cutting trajectory, so as to achieve the purpose of constraining the shape and posture of the processed microlens; The execution module, connected to the control module, outputs a femtosecond laser based on the digital pulse signal from the control module to perform adjusted microlens cutting. Examples include a femtosecond laser or an excimer laser. The 3D scanning module, connected to the control module and the execution module, is used to control the femtosecond laser focus output by the execution module to move freely in 3D space according to the signal output by the control module. An optical module, connected to the execution module, is used to focus the femtosecond laser beam emitted by the execution module onto the cornea to be processed. Preferably, the three-dimensional scanning module includes a remote focusing module, a galvanometer scanning module, and a relay module. The remote focusing module works by moving a single lens using a stepper motor, adjusting the distance between the single lenses to change the focusing position of the objective lens along the optical axis, thus achieving depth scanning. The galvanometer scanning module works by deflecting the x-direction and y-direction scanning galvanometers to move the focusing position of the objective lens in the x and y directions perpendicular to the optical axis. The relay module ensures that the beam can still enter the objective lens during scanning by the galvanometer scanning module. To balance cutting speed and accuracy, the x-axis and y-axis controlled by the galvanometer scanning module are fast axes, while the z-axis controlled by the remote focusing module is a slow axis. This allows the module to achieve rapid scanning within the cutting plane parallel to the XOY plane (reaching a scanning speed of 250 m / s on the x and y axes at a 5μm processing point spacing and a 500 kHz laser fundamental frequency); movement along the z-axis is slower (typically 0.1 mm / s). For example, the cutting signal includes digital pulse signals to drive the remote focusing module, a laser focus position signal to control the galvanometer scanning module, and a digital pulse signal to enable laser output. The femtosecond laser focus position signal is further converted into an analog voltage signal by the DAC system of the control module in the cutting module, used to drive the x-axis and y-axis scanning galvanometers.

[0073] The fourth aspect of this application provides a rapid secondary adjustment device for the visual axis center, comprising: a storage medium and a processor; the storage medium is used to store instructions; the processor is used to operate according to the instructions to execute the method steps performed by the adjustment module in any of the above-described rapid secondary adjustment systems for the visual axis center.

[0074] Figure 6 The automatic alignment method for the visual axis center shown in this invention adjusts the shape of the microlens 11 before and after; wherein Figure 6 (a) and (c) are the top and side views of the microlens 11 before adjustment, respectively, and (b) and (d) are the top and side views of the microlens after adjustment, respectively. The red markers represent the laser optical axis 2 and its intercept point on the target corneal spherical surface 10, and the blue markers represent the visual axis 1 and its intercept point on the target corneal spherical surface 10. This shows that the solution of this application can achieve the goal of matching the microlens with the visual axis direction by adjusting the microlens posture, and the adjustment time only needs to be completed within a few seconds.

[0075] In summary, this invention proposes a rapid secondary adjustment system and device for the visual axis center. By resolving, sampling, and constraining the expression of the microlens surface formed by laser processing and its contour expression on the cutting plane, it compensates for the off-axis movement of the eyeball, improving the accuracy and effectiveness of automatic alignment of the visual axis center. Furthermore, this design enhances comfort during the alignment process while avoiding damage to the eyeball. Through the application of this invention, it is expected to bring substantial improvements to applications such as altering corneal optical properties, removing corneal hyperplasia, and optimizing corneal mechanical properties, thereby improving application effectiveness and reducing discomfort during operation.

[0076] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0077] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of protection of this invention and its equivalents, this invention also intends to include these modifications and variations. The above-described embodiments are merely preferred embodiments given to fully illustrate this invention, and their scope of protection is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this invention are all within the scope of protection of this invention.

Claims

1. A method for rapid secondary adjustment of the visual axis center, characterized in that, Includes the following steps: S1: Obtain microlens fabrication parameters and corneal topography; S2: Generate the microlens processing parameters into microlens shape parameters, and calculate the deflection angle of the visual axis relative to the processing center based on the corneal topography; S3: Based on the shape characteristics of the upper surface, lower surface, side cut, and small incision of the microlens, construct the cutting trajectory surface equation of the upper surface, lower surface, side cut, and small incision of the microlens according to the shape parameters of the microlens. S4: Rotate the analytical expressions of the upper surface, lower surface, lateral cut, and small incision of the microlens around the center of the corneal sphere along the x-axis, y-axis, and z-axis to obtain the three-dimensional analytical expressions of the upper surface, lower surface, lateral cut, and small incision of the microlens after rotation; wherein, the two axes perpendicular to each other of the elliptical trajectory of the lower surface of the microlens are the x-axis and y-axis, and the direction perpendicular to the x-axis and y-axis is the z-axis; S6: Construct several cutting planes parallel to the XOY plane with different z-axis positions, calculate the three-dimensional analytical expressions of the upper surface, lower surface, side cut, and small incision of the microlens and the intersection contours of the cutting planes, and use these intersection contours as the two-dimensional cutting trajectory analytical expressions of the upper surface, lower surface, side cut, and small incision of the microlens. S7: By controlling the cutting trajectory of the upper surface, lower surface, side cut, and small cut of the microlens through geometric constraints, the light output information on each cutting trajectory is obtained; S8: Combine the cutting parameters of the upper surface, lower surface, side cut, and small incision of the microlens obtained in step S6 with the light-emitting point information obtained in step S7 to compile a cutting signal.

2. A rapid secondary adjustment system for the visual axis center, characterized in that, include: The data input module is used to acquire microlens processing parameters and corneal topography. The data generation module is used to generate microlens shape parameters from the microlens processing parameters, and to calculate the deflection angle of the visual axis relative to the processing center based on the corneal topography. The data processing module includes: a surface equation construction module, used to construct the surface equations of the cutting trajectories of the microlens's upper surface, lower surface, lateral cut, and small incision based on the shape characteristics of the microlens's upper surface, lower surface, lateral cut, and incision; a coordinate transformation module, used to rotate the analytical expressions of the cutting surfaces of the microlens's upper surface, lower surface, lateral cut, and small incision around the center of the corneal sphere, along the x-axis, y-axis, and z-axis, to obtain the rotated three-dimensional analytical expressions of the microlens's upper surface, lower surface, lateral cut, and small incision; and a two-dimensional cutting parameter generation module, used to construct several cutting planes parallel to the XOY plane with unequal z-axis positions, and calculate the upper surface, lower surface, lateral cut, and small incision of the microlens respectively. The system generates a 3D analytical expression for the small incision and the intersection contour of the cutting plane, and uses these intersection contours as the 2D analytical expressions for the cutting trajectories of the upper surface, lower surface, side cut, and small incision of the microlens. A light emission range constraint module controls the cutting trajectories of the upper surface, lower surface, side cut, and small incision of the microlens through geometric constraints, obtaining light emission information on each cutting trajectory. A control signal compilation module compiles the cutting parameters of the upper surface, lower surface, side cut, and small incision of the microlens obtained in the 2D cutting parameter generation module with the light emission point information obtained in the light emission range constraint module into a cutting signal. Here, the two mutually perpendicular axes of the elliptical trajectory of the lower surface of the microlens are denoted as the x-axis and y-axis, and the direction perpendicular to the x-axis and y-axis is denoted as the z-axis.

3. The rapid secondary adjustment system for the visual axis center according to claim 2, characterized in that, The system further includes: a microscopic imaging module and / or a data pre-storage module, connected to the data input module; the microscopic imaging module is used to capture corneal topography, and the data pre-storage module is used to store pre-input microlens processing parameters and corneal topography.

4. The rapid secondary adjustment system for the visual axis center according to claim 2, characterized in that, The microlens shape parameters include the upper surface shape parameters, lower surface shape parameters, lateral cut shape parameters, and small incision shape parameters of the microlens; the surface equation construction module constructs the analytical expression of the upper surface of the microlens based on the spherical equation based on the upper surface shape parameters of the microlens, constructs the analytical expression of the lower surface of the microlens based on the ellipsoidal equation based on the lower surface shape parameters of the microlens, and constructs the analytical expression of each conical surface in the lateral cut and small incision of the microlens based on the conical equation, respectively.

5. The rapid secondary adjustment system for the visual axis center according to claim 4, characterized in that, The surface shape equation construction module constructs the analytical expression of the upper surface of the microlens based on the spherical equation by substituting the spherical curvature radius of the upper surface of the microlens into the standard spherical equation to obtain the analytical expression of the upper surface shape. The surface shape equation construction module constructs an analytical expression for the lower surface of the microlens based on the ellipsoid equation using the shape parameters of the lower surface of the microlens. This includes: determining the radius of curvature and asphericity of the XOZ section and the radius of curvature and asphericity of the YOZ section of the lower surface of the microlens, and restricting their proportional relationship to ensure that the lower surface of the microlens is an ellipsoid; then substituting the radius of curvature and asphericity of the XOZ section and the YOZ section of the lower surface of the microlens, and their relationship, into the quadratic surface equation to obtain the analytical expression for the shape of the lower surface. The surface equation construction module constructs analytical expressions for each conical surface in the microlens based on the conical surface equation, including substituting the slope of the generatrix of the conical surface corresponding to the microlens' side cut and small cut into the conical surface analytical equation to obtain the analytical expression for each conical surface in the side cut and small cut.

6. The rapid secondary adjustment system for the visual axis center according to claim 2, characterized in that, The three-dimensional analytical expressions of the upper surface, lower surface, side cut, and small incision of the rotated microlens obtained by the coordinate transformation module are represented by rotation matrices or quaternions calculated using Euler angles.

7. The rapid secondary adjustment system for the visual axis center according to claim 2, characterized in that, In the two-dimensional cutting parameter generation module, the three-dimensional analytical expressions of the upper surface, lower surface, side cut, and small incision of the microlens and the intersection contours of the cutting plane are calculated respectively. These intersection contours are used as the two-dimensional cutting trajectory analytical expressions of the upper surface, lower surface, side cut, and small incision of the microlens. This includes: calculating the two-dimensional cutting trajectory analytical expression of the intersection contour of the upper surface as a circle based on the spherical surface of the upper surface of the microlens and the cutting plane; substituting the z-coordinate of the cutting plane into the equation of the ellipsoid of the lower surface of the microlens to calculate the two-dimensional cutting trajectory analytical expression of the intersection contour of the lower surface as an ellipse; and substituting the z-coordinate of the cutting plane into the equations of the conical surfaces of the side cut and small incision of the microlens respectively to calculate the two-dimensional cutting trajectory analytical expressions of the intersection contour of the side cut as an ellipse and the intersection contour of the small incision as an ellipse.

8. The rapid secondary adjustment system for the visual axis center according to claim 2, characterized in that, In the light emission range constraint module, the light emission point of the two-dimensional cutting trajectory on the upper surface is constrained on the intersecting circular contour of the upper surface sphere and the cutting plane, and is located above the bottom surface of the upper surface; the light emission point of the two-dimensional cutting trajectory on the lower surface is constrained above the bottom surface of the lower surface, and is located within the first segment of the laterally cut conical surface; the light emission point of the two-dimensional cutting trajectory on the first segment of the laterally cut conical surface is constrained between the bottom surface and the top surface of the conical surface of the first segment of the laterally cut conical surface; the light emission point of the two-dimensional cutting trajectory on the second segment of the laterally cut conical surface is constrained between the bottom surface and the top surface of the conical surface of the second segment of the laterally cut conical surface; the light emission point of the two-dimensional cutting trajectory on the small cut is constrained between the bottom surface and the top surface of the conical surface corresponding to the small cut; wherein the top surface of the first segment of the laterally cut conical surface coincides with the bottom surface of the second segment of the laterally cut conical surface.

9. A device for rapid secondary adjustment of the visual axis center, characterized in that, include: The rapid secondary adjustment system and cutting module for the visual axis center as described in any one of claims 2-8; The cutting module includes a control module, an execution module, an optical module, and a three-dimensional scanning module; The control module is used to convert the cutting signal generated by the rapid secondary adjustment system of the visual axis center into a signal that drives the movement of the three-dimensional scanning module and a digital pulse signal that drives the execution module, and to adjust the signal that drives the movement of the three-dimensional scanning module and the digital pulse signal that drives the execution module to achieve cutting in multiple areas within the cutting trajectory of the upper surface, lower surface, side cut, and small incision of the microlens; The execution module is connected to the control module and is used to output a femtosecond laser according to the digital pulse signal output by the control module to perform microlens cutting after adjustment by the visual axis center rapid secondary adjustment system. The three-dimensional scanning module is connected to the control module and the execution module, and is used to control the femtosecond laser focus output by the execution module to move freely in three-dimensional space according to the signal output by the control module. The optical module is connected to the execution module and is used to focus the femtosecond laser beam emitted by the execution module onto the cornea to be processed.

10. A device for rapid secondary adjustment of the visual axis center, characterized in that, include: Storage media and processor; The storage medium is used to store instructions; the processor is used to operate according to the instructions to execute the rapid secondary adjustment method for the visual axis center as described in claim 1.

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