Cornea reflecting spot calculation method and device, electronic equipment and storage medium

Abstract

The invention provides a cornea light reflection point calculation method and device, electronic equipment and a storage medium, and the method comprises the steps: projecting incident light rays emitted by three circles of concentric LED lamp systems onto a cornea, and enabling the reflected light rays of the cornea to form an image of a reflection point on camera equipment; the circle center of the LED lamp system is the position of the optical axis; determining the radius of a circle passing through the two reflection points on the tangent plane based on the image of the reflection points; determining projection light path diagrams of the two LED lamps based on the circle radius, and determining offset data of an optical axis and a visual axis based on the projection light path diagrams; determining a deviation value of the optical axis and the visual axis in a plane based on the deviation data of the optical axis and the visual axis; and determining the position of a cornea reflecting spot based on the deviation value of the optical axis and the visual axis in the plane. According to the invention, the front segment equipment can be better aligned with the eye axis and the equipment optical axis during measurement, so that more accurate measurement data can be obtained, the position of a cornea light reflecting spot can be obtained without adopting an additional light source, the equipment cost is reduced, and the usability of the equipment is improved.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to a method, apparatus, electronic device, and storage medium for calculating corneal light-reflecting points. Background Technology

[0002] Currently, when taking pictures with anterior segment devices, it is necessary to align the optical axis of the device with the visual axis to ensure the accuracy of corneal morphology measurement, improve data repeatability, and guarantee the precision of the final measurement data.

[0003] There are two main types of alignment methods: one is optical, where a light is shone onto the corneal surface under fixation to create a reflective point, which is the location of the corneal light-reflecting point. This method requires additional optical equipment and may also affect the BSCAN (luminance scan) image capture process. The other method uses image recognition to determine the alignment of the optical axis and visual axis. This method is generally accomplished using a frontal camera image. However, different equipment manufacturers use different methods to perform this process. Some manufacturers capture a frontal image of the cornea with a frontal camera and calculate the distance between the pupil center and the optical axis center to determine if the equipment meets the capture requirements. Other manufacturers simultaneously display horizontal and vertical BSCAN images during capture, calculate the highest point in the BSCAN image, and check if it is within a set range to determine if the capture requirements have been met.

[0004] In summary, among the two types of alignment methods mentioned above, optical methods require additional optical equipment, resulting in higher costs; while image recognition methods do not provide sufficiently accurate measurement data, and the equipment is less user-friendly. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method, apparatus, electronic device and storage medium for calculating corneal light-reflecting points, so as to obtain more accurate measurement data, obtain the position of corneal light-reflecting points without the need for an additional light source, reduce equipment costs and increase the ease of use of the equipment.

[0006] In a first aspect, embodiments of the present invention provide a method for calculating corneal light reflection points. The method includes: projecting incident light emitted from a three-circle concentric LED light system onto the cornea, and the reflected light from the cornea forming an image of a reflection point on a camera device; wherein the center of the LED light system is the position of the optical axis; determining the radius of the circle passing through two reflection points on the cross-section based on the image of the reflection point; determining the projection light path diagram of the two LED lights based on the circle radius; determining the offset data between the optical axis and the visual axis based on the projection light path diagram; determining the offset value between the optical axis and the visual axis in the plane based on the offset data between the optical axis and the visual axis; and determining the position of the corneal light reflection point based on the offset value between the optical axis and the visual axis in the plane.

[0007] In an optional embodiment of this application, the LED light system includes: three concentric circles, each concentric circle having a plurality of LED lights arranged thereon; the plurality of LED lights in each concentric circle are symmetrically distributed with respect to the center of the circle, and the plurality of LED lights in each concentric circle are arranged at equal angles; the plurality of LED lights arranged in the inner and outer circles have the same azimuth angle, and the plurality of LED lights arranged in the middle circle are arranged in an alternating pattern with the plurality of LED lights arranged in the inner and outer circles.

[0008] In an optional embodiment of this application, the step of determining the radius of the circle passing through two reflection points on the cross surface based on the image of the reflection points includes: dividing the LED light system into multiple LED light groups; wherein each LED light group includes: two LED lights, and the line connecting the two LED lights in each LED light group passes through the center of the LED light system; determining the reflection points of the two LED lights in the target LED light group from the image of the reflection points; and determining the radius of the circle passing through the reflection points of the two LED lights in the target LED light group on the cross surface based on the image of the reflection points.

[0009] In an optional embodiment of this application, the step of determining the radius of the circle passing through the reflection points of the two LEDs included in the target LED group on the cross-section based on the image of the reflection points includes: determining a first LED from the two LEDs included in the target LED group; determining the estimated position of the reflection point of the first LED based on the image of the reflection points; determining the estimated value of the radius of the circle passing through the reflection points of the two LEDs included in the target LED group on the cross-section based on the estimated position of the reflection point of the first LED; determining the actual position of the reflection point of the first LED; determining whether to update the estimated value of the radius of the circle based on the actual position of the reflection point of the first LED; if yes, updating the estimated value of the radius of the circle based on the actual position of the reflection point of the first LED, and re-determining the actual position of the reflection point of the first LED; if no, using the estimated value of the radius of the circle as the final value of the radius of the circle.

[0010] In an optional embodiment of this application, the step of determining the offset data between the optical axis and the visual axis based on the projection optical path diagram includes: determining the offset data between the optical axis and the visual axis and the positions of the two LEDs based on the projection optical path diagram; determining the error between the calculated positions of the two LEDs; if the error between the calculated positions of the two LEDs is greater than a preset threshold, re-determining the radius of the circle passing through the two reflection points on the cross-section based on the image of the reflection points.

[0011] In an optional embodiment of this application, the step of determining the offset value of the optical axis and the visual axis in the plane based on the offset data of the optical axis and the visual axis includes: taking every two symmetrical and mutually perpendicular LED groups as a pair of LED groups; rotating the line connecting the projection points of the LEDs in each pair of LED groups to a specified angle, calculating the offset data of the optical axis and the visual axis after rotation as the offset data of each pair of LED groups; and taking the average value of the offset data of each pair of LED groups as the offset value of the optical axis and the visual axis in the plane.

[0012] In an optional embodiment of this application, the step of determining the position of the corneal photoreflection point based on the offset value of the optical axis and the visual axis in the plane includes: superimposing the offset value of the optical axis and the visual axis in the plane onto the coordinates of the optical axis to obtain the position of the corneal photoreflection point.

[0013] Secondly, embodiments of the present invention also provide a corneal light-reflection point calculation device, the device comprising: an image module for reflecting points, used to project incident light emitted from a three-circle concentric LED light system onto the cornea, wherein the reflected light from the cornea forms an image of the reflection point on a camera device; wherein the center of the LED light system is the position of the optical axis; a circle radius estimation module, used to determine the circle radius passing through two reflection points on a cross-section based on the image of the reflection points; an offset data estimation module, used to determine the projection light path diagram of the two LED lights based on the circle radius, and to determine the offset data between the optical axis and the visual axis based on the projection light path diagram; a plane offset value calculation module, used to determine the offset value between the optical axis and the visual axis in the plane based on the offset data between the optical axis and the visual axis; and a corneal light-reflection point position determination module, used to determine the position of the corneal light-reflection point based on the offset value between the optical axis and the visual axis in the plane.

[0014] Thirdly, embodiments of the present invention also provide an electronic device, including a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the above-described corneal photometric calculation method.

[0015] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer-executable instructions. When the computer-executable instructions are invoked and executed by a processor, the computer-executable instructions cause the processor to implement the above-described corneal photoreflection point calculation method.

[0016] The embodiments of the present invention bring the following beneficial effects: This invention provides a method, apparatus, electronic device, and storage medium for calculating corneal light reflection points. The method involves projecting incident light from a three-ring concentric LED light system onto the cornea, and the reflected light from the cornea forming an image of the reflection point on a camera device. The center of the LED light system is the position of the optical axis. The radius of the circle passing through two reflection points on the cross-section is determined based on the image of the reflection point. The projection light path diagram of the two LED lights is determined based on the circle radius, and the offset data between the optical axis and the visual axis is determined based on the projection light path diagram. The offset value between the optical axis and the visual axis in the plane is determined based on the offset data between the optical axis and the visual axis. The position of the corneal light reflection point is determined based on the offset value between the optical axis and the visual axis in the plane. In this method, the position of the corneal light reflection point can be calculated using an algorithm, allowing the anterior segment device to better align the eye axis and the device's optical axis during measurement, thereby obtaining more accurate measurement data. The position of the corneal light reflection point can be obtained without the need for an additional light source, reducing equipment costs and increasing ease of use.

[0017] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0018] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A flowchart of a method for calculating corneal light-reflecting points provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of an LED lamp system arrangement provided in an embodiment of the present invention; Figure 3 A schematic diagram of a reflective point on the cornea illuminated by an LED light system, provided in an embodiment of the present invention; Figure 4 A schematic diagram illustrating the grouping of LED lamp reflection points according to an embodiment of the present invention; Figure 5 A schematic diagram illustrating a circle radius estimation method provided in an embodiment of the present invention; Figure 6 A schematic diagram illustrating an offset value estimation method provided in an embodiment of the present invention; Figure 7 A schematic diagram of a corneal reflective dot image provided in an embodiment of the present invention; Figure 8 A schematic diagram of another corneal reflective dot image provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of a corneal light-reflection point calculation device provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Currently, there are two main types of alignment methods: one is optical, where a light is shone onto the corneal surface under fixed vision to create a reflective point, which is the location of the corneal light-reflecting point. This method requires additional optical equipment and may also affect the BSCAN (luminance scan) image capture process. The other method uses image recognition to determine the alignment of the optical axis and visual axis. This method is generally accomplished using a frontal camera image. However, different equipment manufacturers use different methods to perform this process. Some manufacturers capture a frontal image of the cornea with a frontal camera and calculate the distance between the pupil center and the optical axis center to determine if the equipment meets the capture requirements. Other manufacturers simultaneously display horizontal and vertical BSCAN images during capture, calculate the highest point in the BSCAN image, and check if it is within a set range to determine if the capture requirements have been met.

[0023] In summary, among the two types of alignment methods mentioned above, optical methods require additional optical equipment, resulting in higher costs; while image recognition methods do not provide sufficiently accurate measurement data, and the equipment is less user-friendly.

[0024] A corneal topometer is a device for measuring the radius of curvature of the anterior surface of the cornea. Its principle is based on geometric optics related to reflected and refracted light, achieving the measurement purpose by measuring the corneal reflection points and reflected light rays. Iolmaster (an optical biometric instrument using non-contact technology) is based on the principle of corneal reflection imaging. It projects six hexagonally arranged point light sources onto the anterior surface of the cornea. The corneal reflection image is then imaged on a sensor. The corneal reflection image is processed to determine the distance between two point light sources located on the diagonals of the regular hexagon, and thus the radius of curvature is calculated.

[0025] Based on this, the corneal light-reflection point calculation method, apparatus, electronic device, and storage medium provided in this embodiment of the invention specifically provide a corneal light-reflection point calculation method based on a telecentric optical path. This method employs a point light source arrangement similar to that of a corneal topometer, projecting three concentric rings of LEDs onto the cornea. According to the imaging principle of the telecentric optical path, the position of the corneal light-reflection point is calculated using the reflection points of the LEDs, and the offset between the visual axis and the optical axis is calculated.

[0026] To facilitate understanding of this embodiment, a method for calculating corneal light-reflecting points disclosed in this embodiment of the invention will first be described in detail.

[0027] Example 1: This invention provides a method for calculating corneal light reflex points, see [link to relevant documentation]. Figure 1 The flowchart shown illustrates a method for calculating corneal light reflex points, which includes the following steps: Step S102: The incident light emitted by the three concentric LED light system is projected onto the cornea, and the reflected light from the cornea forms an image of the reflection point on the camera device; wherein, the center of the LED light system is the position of the optical axis.

[0028] In this embodiment, the incident light emitted by the three concentric LED light system can be projected onto the cornea. Based on the principle of telecentric imaging, the offset between the visual axis and the optical axis, and the position of the corneal light-reflecting point, can be calculated using the reflection points of the LED lights. Generally, the position of the device's optical axis is known, and the physical coordinates of the corneal light-reflecting point can be calculated based on the offset value.

[0029] In some embodiments, the LED lighting system includes: three concentric circles, each concentric circle having a plurality of LEDs arranged thereon; the plurality of LEDs in each concentric circle are symmetrically distributed with respect to the center of the circle, and the plurality of LEDs in each concentric circle are arranged at equal angles; the plurality of LEDs arranged in the inner and outer circles have the same azimuth angle, and the plurality of LEDs arranged in the middle circle are arranged in an alternating pattern with the plurality of LEDs arranged in the inner and outer circles.

[0030] This embodiment uses an example where each concentric circle has 8 LEDs arranged in a row, and will not be described again hereafter. The three concentric LED light system can form 24 corneal reflective points when projected onto the cornea.

[0031] See Figure 2 The diagram shows an arrangement of LED lights, consisting of three concentric rings of eight LEDs arranged at equal angles, for a total of 24 lights. The outer and inner rings of LEDs are at the same angular position, differing only in distance. The middle ring of LEDs is staggered from the other two rings. The three rings of LEDs are evenly distributed around the optical axis, with the center of the optical axis being its location.

[0032] The LED light system illuminates reflective points on the cornea, and the reflected light forms an image of these reflective points on the camera device. (See also...) Figure 3 The diagram shows a reflective point on the cornea illuminated by an LED light system.

[0033] Step S104: Determine the radius of the circle passing through the two reflection points on the cross-section based on the image of the reflection points.

[0034] In some embodiments, the LED lighting system can be divided into multiple LED groups; wherein each LED group includes: 2 LEDs, the line connecting the 2 LEDs in each LED group passes through the center of the LED lighting system; the reflection point of the 2 LEDs in the target LED group is determined from the image of the reflection point; the radius of the circle passing through the reflection point of the 2 LEDs in the target LED group is determined based on the image of the reflection point.

[0035] In this embodiment, each ring of LEDs can be divided into 4 groups, with 2 LEDs in each group positioned on a diameter line passing through the center of the circle. See also Figure 4 This is a schematic diagram of the grouping of LED light reflection points. LEDs labeled 1 and 2 form one group, LEDs labeled 3 and 4 form another group, and so on.

[0036] The optical design in this embodiment employs a telecentric optical path. A characteristic of a telecentric optical path is that only light rays parallel to the optical axis can be captured by the sensor, thus forming the final reflection point image. From this, we can deduce the optical path of the light emitted by the LED lamp after reflection from the cornea to the sensor for imaging.

[0037] The light emitted by the LED lamp is projected onto the corneal surface and, after reflection, emits reflected rays parallel to the optical axis. According to the principle of light reflection, the angle of incidence and the angle of reflection are equal, so the normal to the corneal surface is the angle bisector of the incident and reflected rays. The physical distance between two LED lamps in the same group is fixed.

[0038] If the optical axis coincides with the visual axis without any offset, the distances from the reflection points of the two LEDs to the corneal light-reflecting points are equal. However, when there is an offset between the optical axis and the visual axis, these two values ​​are no longer equal. On the side where the optical axis is offset, the distance from the reflection point of one LED to the visual axis is greater than the distance from the reflection point of the other LED. However, the sum of the two distances, that is, the distance between the two reflection points, is close to that when there is no offset. Based on this, the radius of the circle passing through the reflection points of the two LEDs on the current cross-section can be estimated. Further investigation reveals that, after obtaining this radius, if the positions of the reflection points of the two LEDs on the corneal surface are known, the actual physical positions of the LEDs can be calculated backwards based on the geometry of the optical path. By comparing the calculated physical positions with the actual physical positions, the offset between the optical axis and the visual axis can be calculated through an iterative method.

[0039] In some embodiments, the first LED can be determined from the two LEDs included in the target LED group; Based on the image of the reflection point, determine the estimated position of the reflection point of the first LED; based on the estimated position of the reflection point of the first LED, determine the estimated value of the radius of the circle passing through the reflection points of the two LEDs included in the target LED group on the cross surface; determine the actual position of the reflection point of the first LED; based on the actual position of the reflection point of the first LED, determine whether to update the estimated value of the circle radius; if yes, update the estimated value of the circle radius based on the actual position of the reflection point of the first LED, and redetermine the actual position of the reflection point of the first LED; if no, use the estimated value of the circle radius as the final value of the circle radius.

[0040] Based on the foregoing, the first step in estimating the optical axis offset is to calculate the radius of the circle at the reflection points of the two LEDs on this cross-section. (See also...) Figure 5 The diagram illustrates a method for estimating the radius of a circle. Assuming the position of the first LED is A, and the reflection point on the corneal surface is B, according to the principle of telecentric light, the reflected ray BC is a ray parallel to the optical axis. Simultaneously, the normal to the circular surface is the direction of the radius.

[0041] First, estimate the radius of the circle. Figure 5 The first LED is located at point A, point B is the reflection point on the circle, and point C is the direction of the reflected ray. The distance from point B to the central axis is t, and the distance from point A to the central axis is T. Since BC is parallel to the central axis, the value of ∠ABC can be calculated as follows: Where AC = Tt, and BC is the working distance of the equipment, which is a known condition. Since BC is parallel to the central axis OD, ∠BOD = ∠ABC / 2. Radius OB = t / sin(∠BOD).

[0042] After obtaining the initial value of the radius, a traversal method can be used to sequentially query the actual position of point B, starting from the 0° angle. For example... Figure 5 As shown, for a point B' on the circle, the direction of the radius from the center O to this point is the direction of the normal. If point B' is the reflection point, then OB' is the angle bisector of ∠AB'C. The point found based on this condition is the actual reflection point. The reflection point B'' is obtained by iterating through the circle once. Because the value of the radius OB is an estimate, it is necessary to compare the distance from B'' to the central axis OD with the value of t. If they are not close, the radius value needs to be updated, and the search repeated until the distance from the reflection point B'' to the central axis is close to the actual value of t. At this point, the radius of the circle is the best estimate, i.e., the final value.

[0043] Step S106: Determine the projection light path diagram of the two LEDs based on the circle radius, and determine the offset data between the optical axis and the visual axis based on the projection light path diagram.

[0044] After calculating the radius of the circle, the projected light path diagrams of the two LEDs can be obtained, and the offset data between the optical axis and the visual axis can be determined based on the projected light path diagrams.

[0045] In some embodiments, the offset data between the optical axis and the visual axis, and the positions of the two LEDs can be determined based on the projected optical path diagram; the error between the calculated positions of the two LEDs can be determined; if the error between the calculated positions of the two LEDs is greater than a preset threshold, the radius of the circle passing through the two reflection points on the cross surface can be re-determined based on the image of the reflection points.

[0046] See also Figure 6 The diagram shows a method for estimating offset values. Figure 6 In the diagram, A and C represent the physical positions of two LEDs, and the distance between them remains constant. If there is a misalignment between the optical axis and the visual axis, the misalignment of the two LEDs occurs simultaneously, and the sum of their misalignment values ​​is 0. Figure 6 In this diagram, t1 and t2 are the distances from the two reflection points to the viewing axis, and the offset between the optical axis and the viewing axis is x. Thus, the physical positions of the two LEDs are T+x and Tx, respectively, denoted as T1 and T2. T1 is the length of AD, and T2 is the length of CD.

[0047] Where the normal angle α1 = asin(t1 / r) and the incident angle is 2×α1, T1 can be calculated using the following formula: T1 = (r×(1-cos(α1))+wd)×tan(2α1)+t1. Similarly, α2 = asin(t2 / r) and the incident angle is 2×α2, T2 = (r×(1-cos(α2))+wd)×tan(2α2)+t1.

[0048] Because the circle radius value still has errors in the above method, the calculated T1 and T2 values ​​will generally have errors exceeding 0.01 mm. This embodiment can use an iterative method to examine the difference between T1+T2 and 2T, iterate the value of the circle radius r, and repeatedly calculate the values ​​of T1 and T2 until the difference between T1+T2 and 2T meets the requirements.

[0049] Step S108: Determine the offset values ​​of the optical axis and the visual axis in the plane based on the offset data of the optical axis and the visual axis.

[0050] The aforementioned steps estimate the offset value in one direction. In this embodiment, the offset in the plane can be further calculated.

[0051] In some embodiments, every two symmetrical and mutually perpendicular LED light groups can be regarded as a pair of LED light groups; the line connecting the projection points of the LEDs of each pair of LED light groups is rotated to a specified angle, and the offset data between the optical axis and the viewing axis after rotation is calculated as the offset data of each pair of LED light groups; the average value of the offset data of each pair of LED light groups is taken as the offset value between the optical axis and the viewing axis in the plane.

[0052] On a plane, the offset between the visual axis and the optical axis is in two directions. The camera device has a total of 24 LEDs in 3 rings, and there are also 24 reflective points on the cornea, which can be divided into 12 pairs. Simultaneously, the lines connecting two pairs of LEDs in each ring are perpendicular to each other. This results in 6 groups of mutually perpendicular LEDs. Except for the group in the middle ring, which is arranged at 0° and 90° angles, the LEDs in the other groups have a certain tilt angle.

[0053] The line connecting the two LEDs forms an angle with the horizontal, so the offset cannot be calculated directly using the method described above. The method here is to rotate the line connecting the projection points to 0° (or 90°) and then use the method above for calculation. After calculation, rotate the offset position back to the original diagonal line. The projection points of a group of mutually perpendicular LEDs yield two offset point coordinates. Draw perpendicular lines from these two coordinate points to the original diagonal line, and calculate the intersection of the two perpendicular lines; this intersection gives the plane offset value. The projection points of 6 groups of LEDs yield 6 offset values; calculate the average of these offset values.

[0054] Step S110: Determine the position of the corneal photoreflection point based on the offset value between the optical axis and the visual axis in the plane.

[0055] In this embodiment, after determining the offset between the optical axis and the visual axis in the plane, the position of the corneal light-reflecting point can be further determined.

[0056] In some embodiments, the offset values ​​of the optical axis and visual axis in the plane can be superimposed on the coordinates of the optical axis to obtain the position of the corneal photoreflection point.

[0057] See Figure 7A schematic diagram of a corneal reflective dot image is shown. Figure 8 A schematic diagram of another corneal reflective dot image is shown. Figure 7 and Figure 8 The image shows the location of the corneal light-reflecting point estimated based on the location of the LED light's reflection point. Figure 8 Compared to Figure 7 More white dots are shown near the center.

[0058] like Figure 7 As shown, the reflective points of the three LED rings on the cornea are distributed around the pupil. Image processing methods were used to obtain the coordinates of these 24 points in the image, and then the physical coordinate values ​​were obtained through object-image transformation. The physical coordinate values ​​of the six sets of LED reflective points were substituted into the algorithm above to calculate six offset values, and their average was calculated to obtain the final offset value. The offset value was then superimposed onto the optical axis coordinates of the camera device to obtain the final corneal reflective point position. Figure 8 As shown, the white dot in the center of the pupil is the calculated position of the corneal light-reflecting point.

[0059] This invention provides a method for calculating corneal light reflection points. Incident light emitted from a three-ring concentric LED light system is projected onto the cornea, and reflected light from the cornea forms an image of reflection points on a camera device. The center of the LED light system is the position of the optical axis. The radius of the circle passing through two reflection points on the cross-section is determined based on the image of the reflection points. The projection light path diagram of the two LED lights is determined based on the circle radius, and the offset data between the optical axis and the visual axis is determined based on the projection light path diagram. The offset value between the optical axis and the visual axis in the plane is determined based on the offset data between the optical axis and the visual axis in the plane. The position of the corneal light reflection point is determined based on the offset value between the optical axis and the visual axis in the plane. In this method, the position of the corneal light reflection point can be calculated using an algorithm, allowing the anterior segment device to better align the eye axis and the device's optical axis during measurement, thereby obtaining more accurate measurement data. The position of the corneal light reflection point can be obtained without the need for an additional light source, reducing equipment costs and increasing ease of use.

[0060] This invention primarily provides a method for estimating the radius of a circle and a method for estimating the offset between the visual axis and the optical axis of the device. Based on the imaging principle of the telecentric optical path, the deviation between the visual axis and the optical axis of the anterior segment measurement device is calculated using the distribution data of the reflection points of the LED light on the corneal surface, thereby obtaining the position of the corneal light-reflecting point. This enables the anterior segment device to obtain more accurate measurement data during measurement.

[0061] Example 2: Corresponding to the above method embodiments, this invention provides a corneal light-reflection point calculation device, see [link to previous document]. Figure 9 The diagram shown illustrates the structure of a corneal photometric calculation device, which includes: The image module 91 of the reflection point is used to project the incident light emitted by the three concentric LED light system onto the cornea, and the reflected light from the cornea forms an image of the reflection point on the camera device; wherein, the center of the LED light system is the position of the optical axis; The circle radius estimation module 92 is used to determine the circle radius passing through two reflection points on the cross surface based on the image of the reflection points; Offset data estimation module 93 is used to determine the projected light path diagram of two LEDs based on the circle radius, and to determine the offset data between the optical axis and the viewing axis based on the projected light path diagram; The offset value calculation module 94 in the plane is used to determine the offset value of the optical axis and the viewing axis in the plane based on the offset data of the optical axis and the viewing axis; The corneal photoreflection point location determination module 95 is used to determine the corneal photoreflection point location based on the offset value between the optical axis and the visual axis in the plane.

[0062] This invention provides a corneal photoreflection point calculation device. Incident light emitted from a three-circle concentric LED light system is projected onto the cornea, and reflected light from the cornea forms an image of the reflection point on a camera device. The center of the LED light system is the position of the optical axis. Based on the image of the reflection point, the radius of the circle passing through two reflection points on the cross-section is determined. Based on the circle radius, the projection light path diagram of the two LED lights is determined, and based on the projection light path diagram, the offset data between the optical axis and the visual axis is determined. Based on the offset data between the optical axis and the visual axis, the offset value of the optical axis and the visual axis in the plane is determined. Based on the offset value of the optical axis and the visual axis in the plane, the position of the corneal photoreflection point is determined. In this method, the position of the corneal photoreflection point can be calculated using an algorithm, allowing the anterior segment device to better align the eye axis and the device's optical axis during measurement, thereby obtaining more accurate measurement data. The position of the corneal photoreflection point can be obtained without the need for an additional light source, reducing equipment costs and increasing ease of use.

[0063] The aforementioned LED lighting system includes: three concentric circles, each with multiple LEDs arranged in it; the multiple LEDs in each concentric circle are symmetrically distributed with respect to the center of the circle, and the multiple LEDs in each concentric circle are arranged at equal angles; the multiple LEDs arranged in the inner and outer circles have the same azimuth angle, and the multiple LEDs arranged in the middle circle are arranged in an alternating pattern with the multiple LEDs arranged in the inner and outer circles.

[0064] The aforementioned circle radius estimation module is used to divide the LED light system into multiple LED light groups; wherein each LED light group includes: 2 LED lights, and the line connecting the 2 LED lights in each LED light group passes through the center of the LED light system; the reflection point of the 2 LED lights in the target LED light group is determined from the image of the reflection point; and the circle radius passing through the reflection point of the 2 LED lights in the target LED light group is determined on the cross-section based on the image of the reflection point.

[0065] The aforementioned circle radius estimation module is used to determine the first LED from the two LEDs included in the target LED light group; determine the estimated position of the reflection point of the first LED based on the image of the reflection point; determine the estimated value of the circle radius passing through the reflection points of the two LEDs included in the target LED light group on the cross surface based on the estimated position of the reflection point of the first LED; determine the actual position of the reflection point of the first LED; determine whether to update the estimated value of the circle radius based on the actual position of the reflection point of the first LED; if yes, update the estimated value of the circle radius based on the actual position of the reflection point of the first LED and redetermine the actual position of the reflection point of the first LED; if no, use the estimated value of the circle radius as the final value of the circle radius.

[0066] The aforementioned offset data estimation module is used to determine the offset data between the optical axis and the visual axis, and the positions of the two LEDs based on the projected optical path diagram; determine the error between the calculated positions of the two LEDs; if the error between the calculated positions of the two LEDs is greater than a preset threshold, re-determine the radius of the circle passing through the two reflection points on the cross-section based on the image of the reflection points.

[0067] The offset value calculation module in the aforementioned plane is used to treat every two symmetrical and mutually perpendicular LED light groups as a pair of LED light groups; rotate the line connecting the projection points of the LEDs in each pair of LED light groups to a specified angle, calculate the offset data between the optical axis and the viewing axis after rotation as the offset data of each pair of LED light groups; and use the average value of the offset data of each pair of LED light groups as the offset value between the optical axis and the viewing axis in the plane.

[0068] The aforementioned corneal photoreflection point location determination module is used to superimpose the offset values ​​of the optical axis and visual axis in the plane onto the coordinates of the optical axis to obtain the corneal photoreflection point location.

[0069] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the corneal light-reflection point calculation device described above can be referred to the corresponding process in the embodiments of the aforementioned corneal light-reflection point calculation method, and will not be repeated here.

[0070] Example 3: This invention also provides an electronic device for running the above-described corneal light-reflection point calculation method; see [link to previous document]. Figure 10 The diagram shows the structure of an electronic device, which includes a memory 100 and a processor 101. The memory 100 is used to store one or more computer instructions, which are executed by the processor 101 to implement the corneal photoreflection point calculation method described above.

[0071] Furthermore, Figure 10The electronic device shown also includes a bus 102 and a communication interface 103, with the processor 101, the communication interface 103 and the memory 100 connected via the bus 102.

[0072] The memory 100 may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 103 (which can be wired or wireless), such as the Internet, wide area network, local area network, metropolitan area network, etc. The bus 102 may be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 10 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0073] Processor 101 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 101 or by instructions in software form. Processor 101 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a readily available storage medium 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 100, and processor 101 reads information from memory 100 and, in conjunction with its hardware, completes the steps of the method described in the foregoing embodiments.

[0074] This invention also provides a computer-readable storage medium storing computer-executable instructions. When these computer-executable instructions are called and executed by a processor, they cause the processor to implement the above-described corneal photometric point calculation method. For specific implementation details, please refer to the method embodiments, which will not be repeated here.

[0075] The computer program products of the corneal light-reflection point calculation method, apparatus and electronic device provided in the embodiments of the present invention include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods in the preceding method embodiments. For specific implementation, please refer to the method embodiments, which will not be repeated here.

[0076] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and / or device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0077] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0078] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0079] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0080] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method of calculating corneal reflection point, characterized in that, The method comprises: projecting incident light rays emitted by a three concentric circle LED light system onto a cornea, reflected light rays of the cornea forming an image of reflection points on a camera device; wherein the center of the LED light system is the position of the optical axis; determining a circle radius passing through two reflection points on a tangent plane based on the image of the reflection points; determining a projection light path diagram of two LED lights based on the circle radius, and determining offset data of the optical axis and the visual axis based on the projection light path diagram; determining an offset value of the optical axis and the visual axis in a plane based on the offset data of the optical axis and the visual axis; determining a corneal photoreflector position based on the offset value of the optical axis and the visual axis in the plane.

2. The method of claim 1, wherein, The LED light system comprises: three concentric circles, each of which is arranged with a plurality of LED lights; The plurality of LED lights of each concentric circle are symmetrically distributed relative to the center, and the plurality of LED lights of each concentric circle are equiangularly arranged; The plurality of LED lights arranged in the inner and outer circles have the same azimuth angle, and the plurality of LED lights arranged in the middle circle are cross arranged with the plurality of LED lights arranged in the inner and outer circles.

3. The method of claim 1, wherein, The step of determining a circle radius passing through two reflection points on a tangent plane based on the image of the reflection points comprises: dividing the LED light system into a plurality of LED light groups; wherein each LED light group comprises: two LED lights, and the connecting line of the two LED lights included in each LED light group passes through the center of the LED light system; determining the reflection points of the two LED lights included in the target LED light group from the image of the reflection points; determining a circle radius passing through the reflection points of the two LED lights included in the target LED light group on a tangent plane based on the image of the reflection points.

4. The method of claim 3, wherein, The step of determining a circle radius passing through the reflection points of the two LED lights included in the target LED light group on a tangent plane based on the image of the reflection points comprises: determining a first LED light from the two LED lights included in the target LED light group; determining an estimated position of the reflection point of the first LED light based on the image of the reflection points; determining an estimated value of the circle radius passing through the reflection points of the two LED lights included in the target LED light group on a tangent plane based on the estimated position of the reflection point of the first LED light; determining an actual position of the reflection point of the first LED light; determining whether to update the estimated value of the circle radius based on the actual position of the reflection point of the first LED light; if yes, updating the estimated value of the circle radius based on the actual position of the reflection point of the first LED light, and redetermining the actual position of the reflection point of the first LED light; if no, taking the estimated value of the circle radius as a final value of the circle radius.

5. The method of claim 1, wherein, The step of determining offset data of the optical axis and the visual axis based on the projection light path diagram comprises: determining offset data of the optical axis and the visual axis based on the projection light path diagram, and positions of the two LED lights; determining an error between the calculated positions of the two LED lights; if the error between the calculated positions of the two LED lights is greater than a preset threshold, redetermining a circle radius passing through two reflection points on a tangent plane based on the image of the reflection points.

6. The method of claim 3, wherein, The step of determining the offset value of the optical axis and the visual axis in the plane based on the offset data of the optical axis and the visual axis comprises: Each 2 symmetrically perpendicular LED lamp groups are taken as a pair of LED lamp groups; The connecting line of the projection points of the LED lamps of each pair of LED lamp groups is rotated to a specified angle, and the offset data of the rotated optical axis and the visual axis are calculated as the offset data of each pair of LED lamp groups; The average value of the offset data of each pair of LED lamp groups is taken as the offset value of the optical axis and the visual axis in the plane.

7. The method of claim 1, wherein, The step of determining the corneal reflection point position based on the offset value of the optical axis and the visual axis in the plane comprises: The offset value of the optical axis and the visual axis in the plane is superimposed on the coordinates of the optical axis to obtain the corneal reflection point position.

8. A corneal reflection point calculation apparatus characterized by comprising: The device comprises: An image module of the reflection point is configured to project incident light emitted by a three-circle concentric LED lamp system onto a cornea, and the reflected light of the cornea forms an image of the reflection point on a camera device; wherein the center of the LED lamp system is the position of the optical axis; A circle radius estimation module is configured to determine the circle radius of the section passing through two reflection points based on the image of the reflection point; An offset data estimation module is configured to determine the projection light path diagram of two LED lamps based on the circle radius, and determine the offset data of the optical axis and the visual axis based on the projection light path diagram; An offset value calculation module in the plane is configured to determine the offset value of the optical axis and the visual axis in the plane based on the offset data of the optical axis and the visual axis; A corneal reflection point position determination module is configured to determine the corneal reflection point position based on the offset value of the optical axis and the visual axis in the plane.

9. An electronic device, comprising: The computer readable storage medium stores computer executable instructions, and the computer executable instructions, when called and executed by the processor, cause the processor to implement the corneal reflection point calculation method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer executable instructions, and the computer executable instructions, when called and executed by the processor, cause the processor to implement the corneal reflection point calculation method of any one of claims 1 to 7.

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