OCT scanning method

Abstract

The invention relates to an OCT scanning method. The method comprises the steps that after an OCT scans an examined eye based on a plurality of scanning lines in an Nth scanning line group, the OCT is controlled to scan the examined eye based on a target scanning line, so that a B-scan image corresponding to the target scanning line is obtained; determining a scanning correction amount according to the obtained B-scan image; and before scanning the examined eye based on the current scanning line in the (N + M) th scanning line group, correcting the first scanning center of the OCT according to the scanning correction amount. By adopting the method, the accuracy of human eyeball tracking can be effectively improved.

Description

Technical Field

[0001] This application relates to the technical field of OCT, and particularly to an OCT scanning method. Background Art

[0002] Optical Coherence Tomography (OCT) is a three-dimensional tomography technology. The OCT images obtained by scanning the human eye can accurately determine the location of eye diseases.

[0003] In the prior art, generally, the movement state of the human eye is located and tracked based on a pupil camera or a fundus image to guide the OCT to track and scan the human eye to obtain OCT images.

[0004] However, due to certain limitations in the resolution and imaging clarity of the images obtained based on the pupil camera or fundus imaging, the accuracy of tracking the human eye is relatively poor. Summary of the Invention

[0005] Based on this, in view of the above technical problems, it is necessary to provide an OCT scanning method, which can effectively improve the accuracy of tracking the human eye by OCT, and further improve the image quality of the obtained OCT images.

[0006] In a first aspect, this application provides an OCT scanning method, including:

[0007] After the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, control the OCT to scan the eye to be examined based on a target scan line to obtain a B-scan image corresponding to the target scan line; determine a scan correction amount according to the obtained B-scan image; before scanning the eye to be examined based on the current scan line in the (N + M)th scan line group, correct the first scan center of the OCT according to the scan correction amount.

[0008] In one embodiment, the target scan line includes a first target scan line and a second target scan line. The second target scan line is the last scan line among the multiple scan lines in the Nth scan line group. The first target scan line passes through the first scan center and is perpendicular to the second target scan line. The obtaining of the B-scan image corresponding to the target scan line includes:

[0009] Obtain a B-scan image corresponding to the second target scan line, and control the OCT to scan the eye to be examined based on the first target scan line to obtain a B-scan image corresponding to the first target scan line.

[0010] In one embodiment, the target scan lines include a first target scan line and a second target scan line. Both the first target scan line and the second target scan line pass through the first scan center, and the first target scan line and the second target scan line are perpendicular to each other. Obtaining the B-scan image corresponding to the target scan lines includes: controlling the OCT to scan the eye to be examined based on the first target scan line and the second target scan line, so as to obtain the B-scan images corresponding to the first target scan line and the second target scan line.

[0011] In one embodiment, determining the scan correction amount according to the obtained B-scan image includes: respectively determining a first offset amount and a second offset amount according to the B-scan image. The B-scan image includes a first B-scan image corresponding to the first target scan line and a second B-scan image corresponding to the second target scan line; wherein, the first offset amount is the offset amount determined according to the first B-scan image, and the first offset amount is used to represent the distance between the corneal vertex and the current first scan center in the direction of the first target scan line, and the second offset amount is the offset amount determined according to the second B-scan image, and the second offset amount is used to represent the distance between the corneal vertex and the current first scan center in the direction of the second target scan line; determining the scan correction amount according to the first offset amount and the second offset amount.

[0012] In one embodiment, respectively determining the first offset amount and the second offset amount according to the B-scan image includes: determining the corneal vertex position in the B-scan image and determining the midline position in the B-scan image; determining the first offset amount and the second offset amount according to the corneal vertex position and the midline position in the B-scan image.

[0013] In one embodiment, determining the corneal vertex position in the B-scan image includes: obtaining the signal intensity map of a plurality of A-scan images corresponding to the B-scan image; determining a target A-scan image from the plurality of A-scan images according to the signal intensity map, and the target A-scan image is the A-scan image with the smallest depth position of the maximum signal intensity among the plurality of A-scan images; determining the position of the target A-scan image in the first B-scan image as the corneal vertex position in the first B-scan image.

[0014] In one embodiment, determining the corneal vertex position in the B-scan image includes: determining the corneal position based on a layering algorithm; performing a fitting process on the corneal surface based on a fitting algorithm to obtain the corneal surface fitting line; determining the vertex of the corneal surface fitting line as the corneal vertex position.

[0015] In one embodiment, determining the scan correction amount according to the first offset and the second offset includes: determining the distance by which the eye to be examined deviates from the first scan center and the angle between the direction of the eye to be examined and the first target scan line according to the first offset and the second offset; and determining the scan correction amount according to the distance and the angle.

[0016] In one embodiment, the scan correction amount includes a first-direction scan correction amount and a second-direction scan correction amount. Correcting the first scan center of the OCT according to the scan correction amount includes: correcting the first scan center of the OCT in the first direction according to the first-direction scan correction amount; and correcting the first scan center of the OCT in the second direction according to the second-direction scan correction amount.

[0017] In one embodiment, before correcting the first scan center of the OCT according to the scan correction amount, the method further includes: if scanning the eye to be examined is for scanning the anterior segment of the eye to be examined, determining the corneal apex of the eye to be examined as the first scan center of the OCT; if scanning the eye to be examined is for scanning the posterior segment of the eye to be examined, determining the first scan center of the OCT according to the macula and / or optic disc of the eye to be examined, or determining the first scan center of the OCT according to the lowest point in the RPE layer of the eye to be examined.

[0018] In a second aspect, the present application further provides an OCT scanning device, including:

[0019] An acquisition module, configured to, after the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, control the OCT to scan the eye to be examined based on a target scan line, so as to acquire a B-scan image corresponding to the target scan line;

[0020] A determination module, configured to determine a scan correction amount according to the acquired B-scan image;

[0021] An execution module, configured to, before scanning the eye to be examined based on the current scan line in the (N + M)th scan line group, correct the first scan center of the OCT according to the scan correction amount.

[0022] In one embodiment, the target scan lines include a first target scan line and a second target scan line. The second target scan line is the last scan line among multiple scan lines in the Nth scan line group. The first target scan line passes through the first scan center and is perpendicular to the second target scan line. The acquisition module is specifically configured to acquire a B-scan image corresponding to the second target scan line, and control the OCT to scan the eye to be examined based on the first target scan line, so as to acquire a B-scan image corresponding to the first target scan line.

[0023] In one embodiment, the target scan lines include a first target scan line and a second target scan line. Both the first target scan line and the second target scan line pass through the first scan center, and the first target scan line and the second target scan line are perpendicular to each other. The acquisition module is specifically configured to control the OCT to scan the eye to be examined based on the first target scan line and the second target scan line, so as to acquire B-scan images corresponding to the first target scan line and the second target scan line.

[0024] In one embodiment, the determination module is specifically configured to respectively determine a first offset and a second offset according to the B-scan image. The B-scan image includes a first B-scan image corresponding to the first target scan line and a second B-scan image corresponding to the second target scan line. Wherein, the first offset is the offset determined according to the first B-scan image, and the first offset is used to represent the distance between the corneal apex and the current first scan center in the direction of the first target scan line. The second offset is the offset determined according to the second B-scan image, and the second offset is used to represent the distance between the corneal apex and the current first scan center in the direction of the second target scan line. The scan correction amount is determined according to the first offset and the second offset.

[0025] In one embodiment, the determination module is specifically configured to determine the corneal apex position in the B-scan image and determine the midline position in the B-scan image. The first offset and the second offset are determined according to the corneal apex position and the midline position of the B-scan image.

[0026] In one embodiment, the determination module is specifically configured to acquire a signal intensity map of multiple A-scan images corresponding to the B-scan image. A target A-scan image is determined from the multiple A-scan images according to the signal intensity map. The target A-scan image is the A-scan image with the smallest depth position of the maximum signal intensity among the multiple A-scan images. The position of the target A-scan image in the first B-scan image is determined as the corneal apex position in the first B-scan image.

[0027] In one embodiment, the determining module is specifically configured to determine the corneal position based on a hierarchical algorithm; perform a fitting process on the corneal surface based on a fitting algorithm to obtain a fitting line of the corneal surface; and determine the vertex of the fitting line of the corneal surface as the corneal vertex position.

[0028] In one embodiment, the determining module is specifically configured to determine the distance by which the eye to be examined deviates from the first scanning center and the angle between the direction of the eye to be examined and the first target scanning line according to the first offset and the second offset; and determine the scanning correction amount according to the distance and the angle.

[0029] In one embodiment, the scanning correction amount includes a first-direction scanning correction amount and a second-direction scanning correction amount. The execution module is specifically configured to perform a correction process on the first scanning center of the OCT in the first direction according to the first-direction scanning correction amount; and perform a correction process on the first scanning center of the OCT in the second direction according to the second-direction scanning correction amount.

[0030] In one embodiment, the execution module is further configured to, if the scanning of the eye to be examined is for scanning the anterior segment of the eye to be examined, determine the corneal vertex of the eye to be examined as the first scanning center of the OCT; if the scanning of the eye to be examined is for scanning the posterior segment of the eye to be examined, determine the first scanning center of the OCT according to the macula and / or optic disc of the eye to be examined, or determine the first scanning center of the OCT according to the lowest point in the RPE layer of the eye to be examined.

[0031] In a third aspect, the present application further provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the method described in any one of the first aspects above is implemented.

[0032] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method described in any one of the first aspects above is implemented.

[0033] In a fifth aspect, the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, the method described in any one of the first aspects above is implemented.

[0034] In the above OCT scanning method, after the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, the OCT is controlled to scan the eye to be examined based on the target scan line to obtain the B-scan image corresponding to the target scan line; the scanning correction amount is determined according to the obtained B-scan image; before the eye to be examined is scanned based on the current scan line in the (N+M)th scan line group, the first scanning center of the OCT is corrected according to the scanning correction amount. In the OCT scanning method provided by this application, after the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, the OCT is controlled to scan the eye to be examined based on the target scan line, so as to determine the scanning correction amount according to the B-scan image corresponding to the target scan line, and the scanning center of the OCT is corrected based on the scanning correction amount to realize tracking scanning of the human eyeball. Since the scanning correction amount is determined based on the B-scan image, and the resolution and imaging clarity of the OCT are both superior to those of the pupil camera, therefore, guiding the OCT to track the human eyeball based on the B-scan image of the OCT can effectively improve the accuracy of tracking the human eyeball. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 It is a schematic flowchart of the OCT scanning method in an embodiment;

[0037] Figure 2 It is a schematic flowchart of the method for determining the scanning correction amount according to the obtained B-scan image in an embodiment;

[0038] Figure 3 It is a schematic flowchart of the method for respectively determining the first offset and the second offset according to the B-scan image in an embodiment;

[0039] Figure 4 It is a schematic flowchart of the method for determining the corneal vertex position in the B-scan image in an embodiment;

[0040] Figure 5 It is a schematic flowchart of the method for determining the corneal vertex position in the B-scan image in an embodiment;

[0041] Figure 6Flow chart of a method for determining a scan correction amount according to the first offset and the second offset in an embodiment;

[0042] Figure 7 Flow chart of a method for correcting a first scan center of an OCT according to the scan correction amount in an embodiment;

[0043] Figure 8 Schematic diagram for determining a scan correction amount in an embodiment;

[0044] Figure 9 Flow chart of an OCT scanning method in another embodiment;

[0045] Figure 10 Flow chart of an OCT scanning method in another embodiment;

[0046] Figure 11 Structural block diagram of an OCT scanning device in an embodiment;

[0047] Figure 12 Internal structure diagram of a computer device in an embodiment;

[0048] Figure 13 Schematic diagram of the position of an A-scan image and the signal intensity diagram of the A-scan image in an embodiment;

[0049] Figure 14 Signal intensity diagram of an A-scan image in an embodiment;

[0050] Figure 15 Schematic diagram of a B-scan image in an embodiment. Detailed implementation manners

[0051] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application 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 only used to explain the present application and are not used to limit the present application.

[0052] Optical Coherence Tomography (OCT) is a three-dimensional tomography technology. The anterior segment OCT image obtained by scanning the human eye can accurately determine the location of corneal lesions.

[0053] In the prior art, generally, a pupil camera is used to achieve positioning and tracking of the movement state of the human eye, so as to guide the OCT to perform tracking scanning on the human eye to obtain an anterior segment OCT image.

[0054] However, due to certain limitations in the resolution and imaging clarity of the pupil camera, the accuracy of tracking the human eye by OCT guided by the pupil camera is poor.

[0055] In view of this, the present application provides an OCT scanning method, which can effectively improve the accuracy of tracking the human eye by OCT.

[0056] The OCT scanning method provided by the embodiment of the present application may have an execution subject which is a computer device, and the computer device may be a server.

[0057] In one embodiment, as Figure 1 shown, an OCT scanning method is provided, and the method includes the following steps:

[0058] Step 101: After the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, control the OCT to scan the eye to be examined based on the target scan line to obtain the B-scan image corresponding to the target scan line.

[0059] Optionally, the multiple scans in the scan line group may be preset by a technician according to actual needs. For example, the multiple scan lines may be multiple scan lines in the x direction, multiple scan lines in the y direction, or multiple scan lines having an angle with the y direction or multiple scan lines having an angle with the x direction.

[0060] Optionally, the B-scan image is also a two-dimensional cross-sectional image, which is generated by the OCT beam scanning across the eye to be examined horizontally.

[0061] Optionally, the target scan line may include one scan line or multiple scan lines.

[0062] In a possible implementation manner, assuming that three scan line groups are set for the eye to be examined, namely the first scan line group, the second scan line group, and the third scan line group, the Nth scan line group may be any one of the three scan line groups. Taking the first scan line group as an example, after the OCT scans the eye to be examined based on the multiple scan lines in the first scan line group, control the OCT to scan the eye to be examined based on the target scan line to obtain the B-scan image corresponding to the target scan line, and then the OCT will continue to scan the eye to be examined based on the multiple scan lines in the next scan line group. That is, the scanning process of the OCT is to scan one scan line group first, then scan the target scan line, and keep looping until the last scan line group is scanned.

[0063] Step 102: Determine the scanning correction amount according to the obtained B-scan image.

[0064] Optionally, the correction amount can be used to correct the scanning center of the OCT. Before the OCT scans the eye to be examined based on multiple scan line groups, a target position can be determined in the eye to be examined first. This target position is the scanning center of the OCT. During the process of scanning the eye to be examined based on the first scan line group, eye movement may occur in the eye to be examined, causing the scanning center to no longer correspond to the target position. Therefore, before scanning the eye to be examined based on the second scan line group, it is necessary to correct the scanning center based on the offset between the scanning center and the target position so that the scanning center corresponds to the target position.

[0065] In a possible implementation manner, the offset between the above-mentioned scanning center and the target position can be determined first based on the B-scan image corresponding to the target scan line, and then the scan correction amount can be determined based on the offset.

[0066] Step 103: Before scanning the eye to be examined based on the current scan line in the (N + M)-th scan line group, correct the first scanning center of the OCT according to the scan correction amount.

[0067] Optionally, both N and M are natural numbers.

[0068] Optionally, the first scanning center is also the scanning center described above.

[0069] In a possible implementation manner, assume that there are three scan line groups set for the eye to be examined, namely the first scan line group, the second scan line group, and the third scan line group. Taking the N-th scan line group as the first scan line group as an example, as described above, during the process of scanning the eye to be examined based on the first scan line group, eye movement may occur in the eye to be examined, causing the first scanning center not to be at the target position. Therefore, before scanning the eye to be examined based on the second scan line group, the scan correction amount can be determined first according to the B-scan image corresponding to the target scan line, and the first scanning center of the OCT can be corrected according to the scan correction amount. After the correction process, then control the OCT to scan the eye to be examined based on multiple scan lines of the second scan line group, that is, after the OCT scans the eye to be examined based on the target scan line, pause the scan first until the scan correction amount is determined based on the target scan line and the first scanning center is corrected based on the target correction amount, and then start to execute the step of scanning the next scan line group.

[0070] In another possible implementation, assume that there are three scanning line groups set for the eye to be examined, namely the first scanning line group, the second scanning line group, and the third scanning line group. Taking the Nth scanning line group as the first scanning line group as an example, as described above, during the process of scanning the eye to be examined based on the first scanning line group, eye movement may occur in the eye to be examined, causing the first scanning center not to be at the target position. Therefore, the scanning correction amount can be determined according to the B-scan image corresponding to the target scanning line. During the process of determining the scanning correction amount, the OCT can continuously execute the scanning process based on the second scanning line group. Assume that during the process of the OCT executing the scanning process based on the third scanning line in the second scanning line group, the scanning correction amount is determined. Then, the first scanning center of the OCT is corrected based on the scanning correction amount. After the correction process, the OCT is then controlled to scan the eye to be examined based on the third scanning line of the second scanning line group. That is, after the OCT scans the eye to be examined based on the target scanning line, the scanning is not paused. After the scanning correction amount is determined based on the target scanning line, the first scanning center is corrected based on the target correction amount.

[0071] For the above OCT scanning method, after the OCT scans the eye to be examined based on multiple scanning lines in the Nth scanning line group, the OCT is controlled to scan the eye to be examined based on the target scanning line to obtain the B-scan image corresponding to the target scanning line; the scanning correction amount is determined according to the obtained B-scan image; before the OCT scans the eye to be examined based on the current scanning line in the (N + M)th scanning line group, the first scanning center of the OCT is corrected according to the scanning correction amount. The OCT scanning method provided in this application controls the OCT to scan the eye to be examined based on the target scanning line after the OCT scans the eye to be examined based on multiple scanning lines in the Nth scanning line group, so as to determine the scanning correction amount according to the B-scan image corresponding to the target scanning line, and correct the scanning center of the OCT based on the scanning correction amount to achieve tracking scanning of the human eyeball. Since the scanning correction amount is determined based on the B-scan image, and the resolution and imaging clarity of the OCT are both superior to those of the pupil camera, therefore, guiding the OCT to track the human eyeball based on the B-scan image of the OCT can effectively improve the accuracy of tracking the human eyeball.

[0072] In an optional embodiment of the present application, before correcting the first scanning center of the OCT according to the scanning correction amount, the method further includes the following steps: If the examination of the eye to be examined is a scan of the anterior segment of the eye to be examined, the corneal apex of the eye to be examined is determined as the first scanning center of the OCT; if the examination of the eye to be examined is a scan of the posterior segment of the eye to be examined, the first scanning center of the OCT is determined according to the macula and / or optic disc of the eye to be examined, or the first scanning center of the OCT is determined according to the lowest point in the RPE layer of the eye to be examined.

[0073] In a possible implementation manner, if it is controlled that the OCT scans the anterior segment of the eye to be examined based on multiple scanning lines in a scanning line group, the corneal apex of the eye to be examined can be determined as the first scanning center of the OCT. The anterior segment of the eye to be examined at least includes the pupil, cornea, and iris structure.

[0074] It should be noted that in the embodiment of the present application, the anterior segment of the eye to be examined is scanned, and the corneal apex of the eye to be examined is determined as the first scanning center of the OCT.

[0075] In another possible implementation manner, if it is controlled that the OCT scans the posterior segment of the eye to be examined based on multiple scanning lines in a scanning line group, the posterior segment of the eye to be examined at least includes the retinal structure. Any point on the macula area or optic disc area of the eye to be examined can be determined as the first scanning center of the OCT. Preferably, the center of the macula can be selected as the first scanning center or the center of the optic disc can be selected as the first scanning center. Alternatively, the first scanning center of the OCT is determined according to the macula area and optic disc area of the eye to be examined. Preferably, a point can be determined on the straight line where the center of the macula and the center of the optic disc are located as the first scanning center.

[0076] In another possible implementation manner, if it is controlled that the OCT scans the posterior segment of the eye to be examined based on multiple scanning lines in a scanning line group, the B-scan image of the eye to be examined can be obtained first, and then the signal intensity map of multiple A-scan images corresponding to the B-scan image can be obtained; the target A-scan image is determined from multiple A-scan images according to the multiple signal intensity maps. The target A-scan image is the A-scan image with the largest depth position of the minimum signal intensity among multiple A-scan images, and the position of the target A-scan image in the B-scan image is determined as the position of the lowest point in the retinal pigment epithelium (RPE) layer in the first B-scan image, and the position of the lowest point in the RPE layer is determined as the first scanning center.

[0077] In another possible implementation, the position of the RPE layer can also be determined based on a hierarchical algorithm, and then the RPE layer can be fitted based on a fitting algorithm to obtain a fitted line of the RPE layer. The lowest point of the fitted line of the RPE layer is determined as the lowest point in the RPE layer, and the lowest point in the RPE layer is determined as the first scanning center.

[0078] It should be noted that if the lowest point in the RPE layer of the eye to be examined is determined as the first scanning center of the OCT, the method for determining the correction amount of the first scanning center during the scanning process is the same as the method for determining the correction amount when the corneal vertex is determined as the first scanning center, and the process of correcting the first scanning center according to the correction amount is also the same, which will not be elaborated in the following text.

[0079] In one embodiment, the target scanning line includes a first target scanning line and a second target scanning line. The second target scanning line is the last scanning line among multiple scanning lines in the Nth scanning line group. The first target scanning line passes through the first scanning center and is perpendicular to the second target scanning line. Obtaining the B-scan image corresponding to the target scanning line includes: obtaining the B-scan image corresponding to the second target scanning line, and controlling the OCT to scan the eye to be examined based on the first target scanning line to obtain the B-scan image corresponding to the first target scanning line.

[0080] In a possible implementation, taking the Nth scanning line group as the first scanning line group as an example, the last scanning line in the first scanning line group can be determined as the second target scanning line, and the B-scan image corresponding to the second target scanning line is obtained. Then, the first target scanning line is determined according to the second target scanning line. The first target scanning line is a scanning line that passes through the first scanning center and is perpendicular to the second target scanning line, and the OCT is controlled to scan the eye to be examined based on the first target scanning line to obtain the B-scan image corresponding to the first target scanning line.

[0081] In an alternative embodiment of the present application, if the target scanning line includes a first target scanning line and a second target scanning line, the second target scanning line is the last scanning line among multiple scanning lines in the Nth scanning line group, and it is determined that the first target scanning line passes through the first scanning center, then the first target scanning line can be determined according to the first scanning center, the second target scanning line, and a preset angle. The preset angle is the angle between the second target scanning line and the first target scanning line, and the preset angle can be set by those skilled in the art according to actual needs.

[0082] In one embodiment, the target scan lines include a first target scan line and a second target scan line. Both the first target scan line and the second target scan line pass through the first scan center, and the first target scan line and the second target scan line are perpendicular to each other. Obtaining the B-scan image corresponding to the target scan lines includes: controlling the OCT to scan the eye to be examined based on the first target scan line and the second target scan line, so as to obtain the B-scan images corresponding to the first target scan line and the second target scan line.

[0083] In a possible implementation manner, after the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, the first target scan line can be determined first based on the first scan center. The first target scan line is a scan line passing through the first scan center. Then, the second target scan line is determined according to the first target scan line. The second target scan line is a scan line passing through the first scan center and perpendicular to the first target scan line. And control the OCT to scan the eye to be examined based on the first target scan line and the second target scan line, so as to obtain the B-scan images corresponding to the first target scan line and the second target scan line.

[0084] In one embodiment, as Figure 2 shown, determining the scan correction amount according to the obtained B-scan image includes the following steps:

[0085] Step 201: Determine a first offset and a second offset respectively according to the B-scan image. The B-scan image includes a first B-scan image corresponding to the first target scan line and a second B-scan image corresponding to the second target scan line.

[0086] Wherein, the first offset is the offset determined according to the first B-scan image, and the first offset is used to represent the distance between the corneal vertex and the current first scan center in the direction of the first target scan line. The second offset is the offset determined according to the second B-scan image, and the second offset is used to represent the distance between the corneal vertex and the current first scan center in the direction of the second target scan line.

[0087] In a possible implementation manner, the corneal vertex position can be determined in the B-scan image corresponding to the first target scan line, and the distance between the corneal vertex position and the current first scan center is the first offset. And the corneal vertex position is determined in the B-scan image corresponding to the second scan line, and the distance between the corneal vertex position and the current first scan center is the second offset.

[0088] Step 202: Determine the scan correction amount according to the first offset and the second offset.

[0089] In a possible implementation manner, the scanning correction amount can be determined based on algorithm processing using the first offset and the second offset.

[0090] In one embodiment, as Figure 3 shown, determining the first offset and the second offset respectively according to the B-scan image includes the following steps:

[0091] Step 301: Determine the corneal vertex position in the B-scan image and determine the midline position of the B-scan image.

[0092] Step 302: Determine the first offset and the second offset according to the corneal vertex position and the midline position of the B-scan image.

[0093] In a possible implementation manner, assuming that the B-scan image corresponding to the first target scan line is the first B-scan image, the first corneal vertex position can be determined based on the first B-scan image, then the midline position of the first B-scan image is determined, and the first offset is determined according to the first corneal vertex position and the midline position. Assuming that the B-scan image corresponding to the second target scan line is the second B-scan image, the second corneal vertex position can be determined based on the second B-scan image, then the midline position of the second B-scan image is determined, and the second offset is determined according to the second corneal vertex position and the midline position.

[0094] In one embodiment, as Figure 4 shown, determining the corneal vertex position in the B-scan image includes the following steps:

[0095] Step 401: Obtain the signal intensity maps of multiple A-scan images corresponding to the B-scan image.

[0096] Step 402: Determine the target A-scan image from the multiple A-scan images according to the signal intensity map.

[0097] Wherein, the target A-scan image is the A-scan image with the smallest depth position of the maximum signal intensity among the multiple A-scan images;

[0098] Step 403: Determine the position of the target A-scan image in the first B-scan image as the corneal vertex position in the first B-scan image.

[0099] In a possible implementation manner, the positions of multiple A-scan images can be determined first in the B-scan image, as Figure 13 shown, Figure 13Five positions of A-scan images were determined from the B-scan image, and five signal intensity maps corresponding to the five A-scan images were obtained. Based on the five signal intensity maps, an A-scan image was determined from the five A-scan images. Specifically, the depth position of the maximum signal intensity in each signal intensity map can be first determined, as shown in Figure 14 shown, Figure 14 where Zo in

[0100] is the depth position of the maximum signal intensity. Then, the A-scan image with the smallest depth position is selected as the target A-scan image, and the position of the target A-scan image in the first B-scan image is determined as the corneal vertex position in the first B-scan image. Figure 5 In one embodiment, as shown in

[0101] determining the corneal vertex position in the B-scan image includes the following steps:

[0102] Step 501, determining the corneal position based on a hierarchical algorithm;

[0103] In one possible implementation, the anterior corneal surface position or the posterior corneal surface position can be determined based on a hierarchical algorithm of deep learning.

[0104] In another possible implementation, the anterior corneal surface position or the posterior corneal surface position can also be determined based on a hierarchical algorithm of the shortest path.

[0105] Step 502, performing a fitting process on the corneal surface based on a fitting algorithm to obtain the corneal surface fitting line; Figure 15 shown, Figure 15 where the A1 line in

[0106] is the anterior corneal surface fitting line. In another possible implementation, the posterior corneal surface can be fitted based on a fitting algorithm to obtain the posterior corneal surface fitting line.

[0107] Step 503, determining the vertex of the corneal surface fitting line as the corneal vertex position.

[0108] In one possible implementation, if the anterior corneal surface fitting line is a parabola, the vertex of the fitting line can be determined as the corneal vertex position.

[0109] In another possible implementation, if the posterior corneal surface fitting line is a parabola, the vertex of the fitting line can be determined as the corneal vertex position.

[0110] In one embodiment, as Figure 6 shown, determining the scan correction amount according to the first offset and the second offset includes the following steps:

[0111] Step 601: Determine the distance by which the eye to be examined deviates from the first scan center and the angle between the direction of the eye to be examined and the first target scan line according to the first offset and the second offset.

[0112] In a possible implementation manner, as Figure 8 shown, X' is the first target scan line, Y' is the second target scan line, the first offset is I0, the second offset is I1, the angle between the first target scan line and the x-axis is alpha, the angle between the direction of the eye to be examined and the first target scan line is theta, and the distance by which the eye to be examined deviates from the first scan center is R. Then I0 = R×cos(theta), I1 = R×sin(theta). By combining these, R = sqrt(I0×I0 + I1×I1).

[0113] Step 602: Determine the scan correction amount according to the distance and the angle.

[0114] Optionally, the scan correction amount includes a first-direction scan correction amount and a second-direction scan correction amount.

[0115] In a possible implementation manner, the first-direction scan correction amount is also the x-axis scan correction amount, and the x-axis scan correction amount is R×cos(alpha + theta). The second-direction scan correction amount is also the y-axis scan correction amount, and the y-axis scan correction amount is R×sin(alpha + theta).

[0116] In one embodiment, as Figure 7 shown, the scan correction amount includes a first-direction scan correction amount and a second-direction scan correction amount. Correcting the first scan center of the OCT according to the scan correction amount includes the following steps:

[0117] Step 701: Correct the first scan center of the OCT in the first direction according to the first-direction scan correction amount;

[0118] Step 702: Correct the first scan center of the OCT in the second direction according to the second-direction scan correction amount.

[0119] In a possible implementation manner, the scanning center of the OCT is corrected in the x direction according to the x-axis scanning correction amount, and the scanning center of the OCT is corrected in the y direction according to the y-axis scanning correction amount. Specifically, the position of the first scanning center may include the x-axis coordinate position and the y-axis coordinate position. The x-axis coordinate position is corrected according to the x-axis correction amount to obtain the target x-axis coordinate position after the correction process, that is, the x-axis correction amount is superimposed on the x-axis coordinate position to obtain the target x-axis coordinate position. The y-axis coordinate position is corrected according to the y-axis correction amount to obtain the target y-axis coordinate position after the correction process, that is, the y-axis correction amount is superimposed on the y-axis coordinate position to obtain the target y-axis coordinate position.

[0120] In an alternative embodiment of the present application, the method further includes: before scanning the eye to be examined based on the current scan line in the (N + M)-th scan line group, correcting the position of the scanning galvanometer of the OCT according to the scan correction amount.

[0121] In a possible implementation manner, the scanning position is controlled by the control system of the OCT, such as the central controller, by controlling the positions of the scanning galvanometer in the x-direction scan and the scanning galvanometer in the y-direction scan. Therefore, it is also necessary to correct the position of the scanning galvanometer of the OCT. Specifically, the x-axis scanning correction amount and the y-axis correction amount are respectively superimposed on the preset scanning positions of the corresponding galvanometers, and the scanning galvanometer is controlled based on the obtained actual scanning positions.

[0122] In an embodiment, as Figure 9 shown, another OCT scanning method is provided. The target scan lines of the OCT scanning method include a first target scan line and a second target scan line. The second target scan line is the last scan line among the multiple scan lines in the N-th scan line group. The first target scan line passes through the first scanning center and is perpendicular to the second target scan line. The method includes the following steps:

[0123] Step 901: After the OCT scans the eye to be examined based on the multiple scan lines in the N-th scan line group, obtain the B-scan image corresponding to the second target scan line, and control the OCT to scan the eye to be examined based on the first target scan line to obtain the B-scan image corresponding to the first target scan line;

[0124] Step 902: Obtain the signal intensity maps of multiple A-scan images corresponding to the B-scan image; determine the target A-scan image from the multiple A-scan images according to the signal intensity maps, where the target A-scan image is the A-scan image with the smallest depth position of the maximum signal intensity among the multiple A-scan images; determine the position of the target A-scan image in the first B-scan image as the corneal vertex position in the first B-scan image; or, determine the corneal position based on a layering algorithm; perform a fitting process on the corneal surface based on a fitting algorithm to obtain the corneal surface fitting line; determine the vertex of the corneal surface fitting line as the corneal vertex position.

[0125] Step 903: Determine the line position in the B-scan image, and determine the first offset and the second offset according to the corneal vertex position and the line position in the B-scan image. The B-scan image includes a first B-scan image corresponding to the first target scan line and a second B-scan image corresponding to the second target scan line; wherein, the first offset is the offset determined according to the first B-scan image, and the first offset is used to represent the distance between the corneal vertex and the current first scan center in the direction of the first target scan line, and the second offset is the offset determined according to the second B-scan image, and the second offset is used to represent the distance between the corneal vertex and the current first scan center in the direction of the second target scan line.

[0126] Step 904: Determine the distance by which the eye to be examined deviates from the first scan center and the angle between the direction of the eye to be examined and the first target scan line according to the first offset and the second offset; determine the scan correction amount according to the distance and the angle, where the scan correction amount includes a first-direction scan correction amount and a second-direction scan correction amount.

[0127] Step 905: Before scanning the eye to be examined based on the current scan line in the (N + M)-th scan line group, perform a correction process on the first scan center of the OCT in the first direction according to the first-direction scan correction amount; perform a correction process on the first scan center of the OCT in the second direction according to the second-direction scan correction amount.

[0128] In one embodiment, as Figure 10 shown, another OCT scanning method is provided. The OCT scanning method includes a first target scan line and a second target scan line. Both the first target scan line and the second target scan line pass through the first scan center, and the first target scan line and the second target scan line are perpendicular to each other. The method includes the following steps:

[0129] Step 1001: After the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, control the OCT to scan the eye to be examined based on the first target scan line and the second target scan line, so as to obtain B-scan images corresponding to the first target scan line and the second target scan line.

[0130] Step 1002: Obtain the signal intensity map of multiple A-scan images corresponding to the B-scan image; determine the target A-scan image from the multiple A-scan images according to the signal intensity map, where the target A-scan image is the A-scan image with the smallest depth position of the maximum signal intensity among the multiple A-scan images; determine the position of the target A-scan image in the first B-scan image as the corneal vertex position in the first B-scan image; or, determine the corneal position based on a layering algorithm; perform a fitting process on the corneal surface based on a fitting algorithm to obtain the corneal surface fitting line; determine the vertex of the corneal surface fitting line as the corneal vertex position.

[0131] Step 1003: Determine the line position in the B-scan image, and determine the first offset and the second offset according to the corneal vertex position and the line position in the B-scan image. The B-scan image includes a first B-scan image corresponding to the first target scan line and a second B-scan image corresponding to the second target scan line; wherein, the first offset is the offset determined according to the first B-scan image, and the first offset is used to represent the distance between the corneal vertex and the current first scan center in the direction of the first target scan line, and the second offset is the offset determined according to the second B-scan image, and the second offset is used to represent the distance between the corneal vertex and the current first scan center in the direction of the second target scan line.

[0132] Step 1004: Determine the distance by which the eye to be examined deviates from the first scan center and the angle between the direction of the eye to be examined and the first target scan line according to the first offset and the second offset; determine the scan correction amount according to the distance and the angle, and the scan correction amount includes a first-direction scan correction amount and a second-direction scan correction amount.

[0133] Step 1005: Before scanning the eye to be examined based on the current scan line in the (N + M)th scan line group, perform a correction process on the first scan center of the OCT in the first direction according to the first-direction scan correction amount; perform a correction process on the first scan center of the OCT in the second direction according to the second-direction scan correction amount.

[0134] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are sequentially shown according to the indications of the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0135] Based on the same inventive concept, an embodiment of the present application further provides an OCT scanning device for implementing the above-mentioned OCT scanning method. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the OCT scanning device provided below can refer to the limitations on the OCT scanning method in the above text, and will not be repeated here.

[0136] In an exemplary embodiment, as Figure 11 shown, an OCT scanning device 1100 is provided, including: an acquisition module 1101, a determination module 1102, and an execution module 1103, where:

[0137] The acquisition module 1101 is configured to, after the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, control the OCT to scan the eye to be examined based on a target scan line, so as to obtain a B-scan image corresponding to the target scan line;

[0138] The determination module 1102 is configured to determine a scan correction amount according to the obtained B-scan image;

[0139] The execution module 1103 is configured to correct the first scan center of the OCT according to the scan correction amount before scanning the eye to be examined based on the current scan line in the (N + M)th scan line group.

[0140] In an embodiment, the target scan line includes a first target scan line and a second target scan line. The second target scan line is the last scan line among the multiple scan lines in the Nth scan line group. The first target scan line passes through the first scan center and is perpendicular to the second target scan line. The acquisition module 1101 is specifically configured to obtain a B-scan image corresponding to the second target scan line, and control the OCT to scan the eye to be examined based on the first target scan line, so as to obtain a B-scan image corresponding to the first target scan line.

[0141] In one embodiment, the target scan lines include a first target scan line and a second target scan line. Both the first target scan line and the second target scan line pass through the first scan center, and the first target scan line and the second target scan line are perpendicular to each other. The acquisition module 1101 is specifically configured to control the OCT to scan the eye to be examined based on the first target scan line and the second target scan line, so as to acquire B-scan images corresponding to the first target scan line and the second target scan line.

[0142] In one embodiment, the determination module 1102 is specifically configured to respectively determine a first offset and a second offset according to the B-scan images. The B-scan images include a first B-scan image corresponding to the first target scan line and a second B-scan image corresponding to the second target scan line. Wherein, the first offset is the offset determined according to the first B-scan image, and the first offset is used to represent the distance between the corneal apex and the current first scan center in the direction of the first target scan line. The second offset is the offset determined according to the second B-scan image, and the second offset is used to represent the distance between the corneal apex and the current first scan center in the direction of the second target scan line. The scan correction amount is determined according to the first offset and the second offset.

[0143] In one embodiment, the determination module 1102 is specifically configured to determine the corneal apex position in the B-scan image and determine the midline position in the B-scan image. The first offset and the second offset are determined according to the corneal apex position and the midline position of the B-scan image.

[0144] In one embodiment, the determination module 1102 is specifically configured to obtain a signal intensity map of a plurality of A-scan images corresponding to the B-scan image. A target A-scan image is determined from the plurality of A-scan images according to the signal intensity map. The target A-scan image is the A-scan image with the smallest depth position of the maximum signal intensity among the plurality of A-scan images. The position of the target A-scan image in the first B-scan image is determined as the corneal apex position in the first B-scan image.

[0145] In one embodiment, the determination module 1102 is specifically configured to determine the corneal position based on a layering algorithm. The corneal surface is fitted based on a fitting algorithm to obtain a fitted line of the corneal surface. The vertex of the fitted line of the corneal surface is determined as the corneal apex position.

[0146] In one embodiment, the determining module 1102 is specifically configured to determine the distance by which the eye to be examined deviates from the first scanning center and the angle between the direction of the eye to be examined and the first target scanning line according to the first offset and the second offset; and determine the scanning correction amount according to the distance and the angle.

[0147] In one embodiment, the scanning correction amount includes a first-direction scanning correction amount and a second-direction scanning correction amount. The execution module 1103 is specifically configured to perform correction processing on the first scanning center of the OCT in the first direction according to the first-direction scanning correction amount; and perform correction processing on the first scanning center of the OCT in the second direction according to the second-direction scanning correction amount.

[0148] In one embodiment, the execution module 1103 is further configured to, if the scanning of the eye to be examined is for scanning the anterior segment of the eye to be examined, determine the corneal apex of the eye to be examined as the first scanning center of the OCT; if the scanning of the eye to be examined is for scanning the posterior segment of the eye to be examined, determine the first scanning center of the OCT according to the macula and / or optic disc of the eye to be examined, or determine the first scanning center of the OCT according to the lowest point in the RPE layer of the eye to be examined.

[0149] Each module in the above OCT scanning device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or be independent of it, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above respective modules.

[0150] In an exemplary embodiment, a computer device is provided. The computer device can be a server, and its internal structure diagram can be as Figure 12 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used for the processor to exchange information with external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. The computer program, when executed by the processor, implements an OCT scanning method.

[0151] Those skilled in the art can understand that Figure 12 The structure shown in Figure 12 is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0152] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps described in any one of the above embodiments are implemented.

[0153] In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps described in any one of the above embodiments are implemented.

[0154] In an embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the steps described in any one of the above embodiments are implemented.

[0155] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0156] The above-described embodiments only represent several implementation manners of this application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

Claims

1. An OCT scanning method, characterized in that, The method includes: After the OCT scans the eye to be examined based on multiple scan lines in the Nth scan line group, controlling the OCT to scan the eye to be examined based on the target scan line to obtain a B-scan image corresponding to the target scan line; Determining a scan correction amount according to the obtained B-scan image; Before scanning the eye to be examined based on the current scan line in the (N + M)th scan line group, correcting the first scan center of the OCT according to the scan correction amount.

2. The method according to claim 1, characterized in that, The target scan line includes a first target scan line and a second target scan line. The second target scan line is the last scan line among the multiple scan lines in the Nth scan line group. The first target scan line passes through the first scan center and is perpendicular to the second target scan line. Obtaining the B-scan image corresponding to the target scan line includes: Obtaining a B-scan image corresponding to the second target scan line, and controlling the OCT to scan the eye to be examined based on the first target scan line to obtain a B-scan image corresponding to the first target scan line.

3. The method according to claim 1, characterized in that, The target scan line includes a first target scan line and a second target scan line. Both the first target scan line and the second target scan line pass through the first scan center, and the first target scan line and the second target scan line are perpendicular to each other. Obtaining the B-scan image corresponding to the target scan line includes: Controlling the OCT to scan the eye to be examined based on the first target scan line and the second target scan line to obtain B-scan images corresponding to the first target scan line and the second target scan line.

4. The method according to claim 2 or 3, characterized in that, The determining the scan correction amount according to the obtained B-scan image includes: Respectively determining a first offset amount and a second offset amount according to the B-scan image. The B-scan image includes a first B-scan image corresponding to the first target scan line and a second B-scan image corresponding to the second target scan line; Wherein, the first offset amount is the offset amount determined according to the first B-scan image, and the first offset amount is used to represent the distance between the corneal apex and the current first scan center in the direction of the first target scan line. The second offset amount is the offset amount determined according to the second B-scan image, and the second offset amount is used to represent the distance between the corneal apex and the current first scan center in the direction of the second target scan line; Determining the scan correction amount according to the first offset amount and the second offset amount.

5. The method according to claim 4, wherein The respectively determining the first offset amount and the second offset amount according to the B-scan image includes: Determining the corneal apex position in the B-scan image, and determining the line position in the B-scan image; Determining the first offset amount and the second offset amount according to the corneal apex position and the line position in the B-scan image.

6. The method according to claim 5, characterized in that, The determining the corneal apex position in the B-scan image includes: Obtain the signal intensity map of multiple A-scan images corresponding to the B-scan image; Determine a target A-scan image from the multiple A-scan images according to the signal intensity map, where the target A-scan image is the A-scan image with the smallest depth position of the maximum signal intensity among the multiple A-scan images; Determine the position of the target A-scan image in the first B-scan image as the corneal vertex position in the first B-scan image.

7. The method according to claim 5, wherein The determining the corneal vertex position in the B-scan image includes: Determine the corneal position based on a hierarchical algorithm; Perform a fitting process on the corneal surface based on a fitting algorithm to obtain the corneal surface fitting line; Determine the vertex of the corneal surface fitting line as the corneal vertex position.

8. The method according to claim 4, wherein The determining the scan correction amount according to the first offset and the second offset includes: Determine the distance by which the eye to be examined deviates from the first scan center and the angle between the direction of the eye to be examined and the first target scan line according to the first offset and the second offset; Determine the scan correction amount according to the distance and the angle.

9. The method according to claim 1, wherein The scan correction amount includes a first-direction scan correction amount and a second-direction scan correction amount. The correcting the first scan center of the OCT according to the scan correction amount includes: Correct the first scan center of the OCT in the first direction according to the first-direction scan correction amount; Correct the first scan center of the OCT in the second direction according to the second-direction scan correction amount.

10. The method according to claim 1, characterized in that, Before the correcting the first scan center of the OCT according to the scan correction amount, the method further includes: If the scanning of the eye to be examined is for the anterior segment of the eye to be examined, then determine the corneal vertex of the eye to be examined as the first scan center of the OCT; If the scanning of the eye to be examined is for the posterior segment of the eye to be examined, then determine the first scan center of the OCT according to the macula and / or optic disc of the eye to be examined, or determine the first scan center of the OCT according to the lowest point in the RPE layer of the eye to be examined.

Images