A method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus

Abstract

The invention discloses a method for adaptively filling laser spots in fundus mesoplasma lesion areas, and specifically relates to the technical field of mesoplasma lasers. A laser spot filling rule is designed to provide a basis for the detailed design of a laser spot adaptive filling algorithm. The laser spot filling rule includes a spot uniform distribution rule, a restricted area spot avoidance rule, and a spot optimization filling rule. The spot optimization filling rule: according to the initial lesion area of ​​the patient, the laser spot is filled according to the spot uniform distribution rule and the restricted area spot avoidance rule; the lesion area is then rotated around a selected axis according to a set angle to obtain a rotated lesion area, and the laser spot is filled again according to the uniform distribution rule; the final spot center, that is, the spot position, is obtained by reverse rotation and spot avoidance rule; the laser spot adaptive filling method is specifically designed according to the laser spot filling rule, including a rectangular frame positioning module, a spot center calculation module, a lesion area rotation module, and a restricted area spot removal module.

Description

Technical Field

[0001] The invention relates to the technical field of mesoplasm laser technology, and in particular to a method for adaptively filling laser spots in a mesoplasm lesion area of ​​a fundus. Background Art

[0002] At present, clinical laser surgery equipment is mainly divided into navigation laser equipment and traditional laser-micropulse laser equipment. In terms of laser spot filling, the above-mentioned equipment provides single-point arrangement and multi-point arrangement functions, requiring ophthalmologists to select the appropriate arrangement mode according to the patient's fundus lesion morphology, size and other characteristics, and manually complete the preoperative laser spot arrangement planning task.

[0003] In ophthalmic surgery, traditional laser-micropulse laser equipment requires ophthalmologists to observe the patient's fundus image in real time and then operate the laser to emit the laser, which puts a lot of pressure on the operation. However, navigation laser equipment does not require the doctor to stare at the device lens throughout the operation. It has a high level of automation and flexible operation, and is widely used in the treatment of ophthalmic diseases. At present, fundus images can be obtained through scanning laser ophthalmoscopes, and the image can be used to assist in the navigation of laser equipment to plan the laser spot in the treatment area of ​​macular edema; fundus angiography images or fundus OCT images can also be used to assist in the filling of laser spots, and navigation laser equipment can be used to treat the mid-sclera. The above methods all achieve effective treatment of fundus-related diseases through navigation laser equipment, but the above methods completely rely on the auxiliary tools provided by the equipment when filling the laser spot in the mid-sclera lesion area, and cannot perform adaptive filling of the spot.

[0004] At present, there is still a blank in the research on the adaptive filling technology of laser spot in the fundus mid-plasma lesion area. Although the existing fundus laser equipment provides single-point and multi-point layout modes, ophthalmologists are still required to select the appropriate mode based on the morphology, size and other characteristics of the mid-plasma lesions, and manually complete the layout of the laser spot based on clinical experience. The background algorithm cannot independently infer the boundary changes of the mid-plasma lesion area, the vascular distribution of the mid-plasma lesion area, the location of the non-mid-plasma lesion area, and the macular forbidden area, and cannot achieve adaptive filling of the laser spot.

[0005] In addition, the boundary of the mesothelioma lesion is irregular and varies from person to person. The efficiency of planning the spot in the mesothelioma lesion area by using the multi-point arrangement mode is relatively high, but the laser spot will be planned to the non-mesothelioma lesion area near the boundary of the lesion area. Usually, ophthalmologists will use the erase function to remove the spot in the non-mesothelioma lesion area, and use the single-point mode to fine-tune the spot layout near the lesion boundary to prevent laser damage to normal fundus tissue; however, when the mesothelioma lesion area is large, more areas need to be manually fine-tuned by the doctor, and the single-point mode is inefficient and not accurate; the distribution of fundus blood vessels is criss-crossed and extremely irregular. In order to prevent the occurrence of metabolic imbalance of normal fundus tissue caused by laser damage to the thick blood vessels of the fundus, the doctor must avoid the thick blood vessel area of ​​the fundus during the manual arrangement of the laser spot. This process requires careful inspection by the doctor and consumes time and energy. At the same time, the multi-point arrangement modes of the spot of the existing equipment, such as matrix and arc, are only auxiliary for the rapid arrangement of the spot, and do not consider the optimization and filling of the laser spot. Summary of the invention

[0006] In the laser planning stage of the mid-plasma lesion area, when the mid-plasma lesion area is large, the efficiency and accuracy of using the single-point mode are low; the laser layout needs to manually avoid the thick blood vessel area of ​​the fundus, the macular no-shooting area and other locations, which is time-consuming and labor-intensive; and the multi-point arrangement mode of the light spot of the existing equipment does not take into account the optimized filling of the laser spot.

[0007] To solve the above problems, a method for adaptive filling of laser spot in the mid-plasma lesion area of ​​the fundus was proposed, which can effectively avoid the laser forbidden areas such as thick blood vessels in the lesion area, non-lesion area, macula area, etc., and realize adaptive filling of laser spot.

[0008] In order to achieve the above-mentioned object, the present invention provides the following technical solutions: a method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus, designing laser spot filling rules, and providing a basis for the detailed design of the laser spot adaptive filling algorithm, the laser spot filling rules including spot uniform distribution rules, restricted area spot avoidance rules, and spot optimization filling rules;

[0009] Spot optimization filling rule: according to the initial lesion area of ​​the patient, fill the laser spot according to the spot uniform distribution rule and the forbidden area spot avoidance rule; then rotate the lesion area around the selected axis at the set angle to obtain the rotated lesion area, and fill the laser spot again according to the uniform distribution rule; obtain the final spot center, that is, the spot position, through reverse rotation and spot avoidance rule;

[0010] According to the laser spot filling rules, the laser spot adaptive filling method is specifically designed, including a rectangular frame positioning module, a spot center calculation module, a lesion area rotation module, and a restricted area spot removal module; the method automatically completes the feasibility judgment of laser spot arrangement according to the lesion boundary position, the position of the thick blood vessels in the mid-plasma lesion area, and the position of the macular area, and realizes the adaptive filling goal of the laser spot in the mid-plasma lesion area;

[0011] According to the spot optimization filling rule, the corresponding laser spot adaptive filling algorithm is designed. The specific design steps are as follows:

[0012] S1. Input IR image, mark the thick blood vessel segment, macular forbidden area and the boundary of mid-plasma lesion area;

[0013] S2, lesion area rotation module, used for rotation center calculation, rotation angle setting, rotation matrix calculation and lesion area rotation, wherein the forward rotation angle is calculated according to the provided formula, the reverse rotation angle is the negative number of the forward rotation angle, and the forward and reverse rotation angles are substituted into the rotation matrix calculation formula to obtain the forward and reverse rotation matrices respectively;

[0014] S3, rectangular frame positioning module, used for lesion centroid positioning and rectangular frame boundary positioning;

[0015] S4, a light spot center calculation module, used to calculate the light spot center inside the rectangular frame and the light spot center at the border of the rectangular frame;

[0016] S5, restricted area spot removal module, used for spot removal in non-lesion area, thick blood vessel area and macular area.

[0017] Preferably, the light spots are evenly distributed in a rule: different arrangement templates are obtained by setting different light spot spacing distances, thereby achieving different laser spot filling results; and the light spot spacings in the horizontal and vertical directions are set to the same distance.

[0018] Preferably, the restricted area spot avoidance rule is: setting an external rectangular frame of the mid-plasma lesion area, and dividing the area into the lesion area, the non-lesion area, the thick blood vessel segment in the mid-plasma lesion area, and the macular area; then, performing preliminary filling of the laser spot according to the spot uniform distribution rule; using Boolean operations to determine whether the laser spot intersects with the above-mentioned area, removing the intersection area, and obtaining the filling result.

[0019] Preferably, the spot optimization filling rule is: according to the patient's initial lesion area, the laser spot is filled according to the uniform distribution rule and the spot avoidance rule; the lesion area is then rotated around the selected axis at a set angle to obtain the rotated lesion area, and the laser spot is filled again according to the uniform distribution rule; the final spot center, i.e., the spot position, is obtained through reverse rotation and spot avoidance rule.

[0020] During the filling process, different laser spot arrangement results are obtained by setting multiple rotation angles, based on the ratio of the total area of ​​the laser spot in the lesion area to the area of ​​the lesion area. The specific formula is as follows:

[0021] P r =N p ×S ap / S L ;

[0022] Among them, P r Indicates ratio; N p Indicates the number of laser spots arranged in the lesion area; S ap Represents the area of ​​a single laser spot; S L is the area of ​​the mid-plasma lesion.

[0023] Preferably, in S2, the rotation center is calculated as:

[0024]

[0025] Rotation angle setting:

[0026]

[0027] Rotation matrix calculation:

[0028]

[0029] Rotation of the lesion area:

[0030]

[0031] Among them, W m and H m Respectively represent the width and height of the IR image; R x and R y Respectively represent the horizontal and vertical coordinates of the rotation center of the lesion area; M R represents the rotation matrix; θ R is the rotation angle; R N is the maximum total number of rotations, and its value is specified by the operator before the algorithm is executed; r n is the number of times the current rotation is performed; (i, j) is the coordinate of the point to be rotated; (i', j') is the coordinate of the point after rotation.

[0032] Preferably, in S3, the lesion centroid is located:

[0033] The morphology of the mid-plasma lesions in different patients is quite different. The mid-plasma lesion area is an irregular shape. Therefore, the centroid position of the mid-plasma lesion area is determined according to the following method of locating the centroid of an irregular geometric plane:

[0034]

[0035] in, and Respectively represent the abscissa and ordinate of the centroid of the mid-plasma lesion area; S A Indicates mid-cytoplasmic lesion area; x l and l S A The horizontal and vertical coordinates of any point in the.

[0036] Rectangular frame boundary positioning:

[0037]

[0038] Among them, I IR represents the IR image of the patient, whose size is W m ×H m , (i, j) is the coordinate of the pixel in the image; L up and L up_X are the candidate value and final value of the upper boundary of the rectangular box; L down and L down_X are the candidate value and final value of the lower boundary of the rectangular box respectively; L left and L left_Y are the candidate value and final value of the left boundary of the rectangular box; L right and L right_Y They are the candidate value and final value of the right boundary of the rectangular box respectively.

[0039] Preferably, in S4, a corresponding algorithm is designed according to the uniform distribution rule, and uniform filling of the light spot is achieved by calculating the center position of the light spot, wherein the calculation process of the light spot center at the boundary of the rectangular frame and the light spot center inside the rectangular frame is as follows:

[0040] Center of the light spot inside the rectangular frame:

[0041]

[0042] The center of the light spot at the border of the rectangular frame:

[0043]

[0044] Among them, (X c ,Y c )and Respectively represent the current spot center coordinates and the previous spot center coordinates; n x and n y It is the label variable in the program loop process; R L and D S They represent the spot radius variable and the spot spacing variable respectively.

[0045] Preferably, in S5, a specific design of a restricted area spot removal algorithm is performed according to the laser spot avoidance rule, and the process is expressed as follows:

[0046] Spot removal in non-lesion areas:

[0047]

[0048]

[0049]

[0050]

[0051] in, and Respectively represent the rotation angle θ R The binary image of the lesion in the plasma and the initial filling image of the corresponding spot at that time; a1, a2, a3, and a4 represent marker variables, which have different values ​​and are used for Boolean operations; Express and The calculation result after the addition operation is performed; I plate Represents the laser spot template, whose size is N s ×N s ; N g Indicates the total number of initial fills of the light spot, (X c (g),Y c (g)) is the center coordinate of the g-th light spot; I P (g) indicates I plate and The dot product of the pixels at the corresponding position in ; 1{·} is the indicator function, which outputs 1 when the internal condition is met; and Respectively represent the statistical values ​​under the corresponding conditions; (X c_new (g),Y c_new (g)) represents the center coordinate of the gth spot among the remaining spots after removing the spots in the non-mesoplasmic lesion area;

[0052] Spot removal in thick blood vessel area:

[0053]

[0054] in, and Respectively represent the rotation angle θ R The binary image of blood vessels and the image based on (X c_new (g),Y c_new (g)) The spot filling image of the mid-plasma lesion area; Express and The calculation result after the addition operation; N g0 It represents the total number of remaining spots after removing the spots in the non-mesoplasmic lesion area, (X c_new (g0),Y c_new (g0)) is the center coordinate of the g0th spot in the mid-plasma lesion area; P0 (g0) represents I plate and The dot product of the pixels at corresponding positions in ; and Respectively represent the statistical values ​​under the corresponding conditions; It represents the center coordinate of the g0th spot among the remaining spots after removing the intravascular spots in the mid-plasma lesion area;

[0055] Macular spot removal:

[0056]

[0057]

[0058] in, and Respectively represent the rotation angle θ R The binary image of the macular area and the The spot filling image of the mid-plasma lesion area; Express and The calculation result after the addition operation; N g1 It indicates the total number of remaining spots after removing the intravascular spots in the mid-plasma lesion area. is the center coordinate of the g1th spot in the mid-plasma lesion area; I P1 (g1) indicates I plate and The dot product of the pixels at corresponding positions in ; and Respectively represent the statistical values ​​under the corresponding conditions; It represents the center coordinate of the g1th spot among the remaining spots after removing the spot in the macular area of ​​the lesion.

[0059] The present invention has the following advantages:

[0060] The method of the present invention is specifically designed according to the laser spot filling rule, including a rectangular frame positioning module, a spot center calculation module, a lesion area rotation module, and a forbidden area spot removal module; the method automatically completes the feasibility judgment of laser spot arrangement according to the lesion boundary position, the thick blood vessel position in the mid-plasma lesion area, and the macular area position, and realizes the adaptive filling target of the laser spot in the mid-plasma lesion area. Compared with the prior art, the method solves the problem of low efficiency and low accuracy in the single-point mode in the laser planning link of the mid-plasma lesion area when the mid-plasma lesion area is large; it avoids the need to manually avoid the thick blood vessel area of ​​the fundus, the macular forbidden area and other positions in the laser arrangement, which wastes time and energy; and the realization of the multi-point arrangement mode of the spot does not consider the optimized filling of the laser spot. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 A schematic diagram of the laser spot arrangement provided by the present invention;

[0062] Figure 2 This is a diagram of the architecture of the laser spot adaptive filling technology solution provided by the present invention;

[0063] Figure 3 The laser spot arrangement template diagrams with three different spacings provided by the present invention;

[0064] Figure 4 A schematic diagram of laser spot avoidance in the restricted area provided by the present invention;

[0065] Figure 5 A schematic diagram of laser spot optimization filling provided by the present invention;

[0066] Figure 6 A flow chart of the adaptive filling of laser spots in the mid-plasma lesion area provided by the present invention;

[0067] Figure 7 A schematic diagram of the rectangular frame positioning of the lesion provided by the present invention;

[0068] Figure 8 The light spot filling results based on different samples provided by the present invention;

[0069] Fig. 9 The present invention provides different R and R L The spot filling result. DETAILED DESCRIPTION

[0070] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] like Figure 1-7 As shown, this embodiment provides a method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus, designs laser spot filling rules, and provides a basis for the detailed design of the laser spot adaptive filling algorithm. The laser spot filling rules include spot uniform distribution rules, restricted area spot avoidance rules, and spot optimization filling rules.

[0072] Spot optimization filling rule: according to the initial lesion area of ​​the patient, fill the laser spot according to the spot uniform distribution rule and the forbidden area spot avoidance rule; then rotate the lesion area around the selected axis at the set angle to obtain the rotated lesion area, and fill the laser spot again according to the uniform distribution rule; obtain the final spot center, that is, the spot position, through reverse rotation and spot avoidance rule;

[0073] According to the laser spot filling rules, the laser spot adaptive filling method is specifically designed, including a rectangular frame positioning module, a spot center calculation module, a lesion area rotation module, and a restricted area spot removal module; the method automatically completes the feasibility judgment of laser spot arrangement according to the lesion boundary position, the position of the thick blood vessels in the mid-plasma lesion area, and the position of the macular area, and realizes the adaptive filling goal of the laser spot in the mid-plasma lesion area;

[0074] According to the spot optimization filling rule, the corresponding laser spot adaptive filling algorithm is designed. The specific design steps are as follows:

[0075] S1. Input IR image, mark the thick blood vessel segment, macular forbidden area and the boundary of mid-plasma lesion area;

[0076] S2, lesion area rotation module, used for rotation center calculation, rotation angle setting, rotation matrix calculation and lesion area rotation, wherein the forward rotation angle is calculated according to the provided formula, the reverse rotation angle is the negative number of the forward rotation angle, and the forward and reverse rotation angles are substituted into the rotation matrix calculation formula to obtain the forward and reverse rotation matrices respectively;

[0077] S3, rectangular frame positioning module, used for lesion centroid positioning and rectangular frame boundary positioning;

[0078] S4, a light spot center calculation module, used to calculate the light spot center inside the rectangular frame and the light spot center at the border of the rectangular frame;

[0079] S5, restricted area spot removal module, used for spot removal in non-lesion area, thick blood vessel area and macular area.

[0080] Uniform distribution rule of light spots: by setting different light spot spacing distances, different arrangement templates are obtained, thereby achieving different laser spot filling results; the light spot spacing in the horizontal and vertical directions is set to the same distance.

[0081] The rules for avoiding the restricted area light spot are as follows: a rectangular frame is set outside the mid-plasma lesion area, and the lesion area, non-lesion area, thick blood vessel segment in the mid-plasma lesion area, and macular area are divided; then, the laser spot is preliminarily filled according to the spot uniform distribution rule; Boolean operations are used to determine whether the laser spot intersects with the above-mentioned areas, and the intersection area is removed to obtain the filling result.

[0082] Spot optimization filling rule: fill the laser spot according to the patient's initial lesion area according to the uniform distribution rule and the spot avoidance rule; then rotate the lesion area around the selected axis at a set angle to obtain the rotated lesion area, and fill the laser spot again according to the uniform distribution rule; obtain the final spot center, i.e. the spot position, through reverse rotation and spot avoidance rule.

[0083] During the filling process, different laser spot arrangement results are obtained by setting multiple rotation angles, based on the ratio of the total area of ​​the laser spot in the lesion area to the area of ​​the lesion area. The specific formula is as follows:

[0084] Among them, P r Indicates ratio; N p Indicates the number of laser spots arranged in the lesion area; S ap Represents the area of ​​a single laser spot; S L is the area of ​​the mid-plasma lesion.

[0085] In S2, the rotation center is calculated:

[0086]

[0087] Rotation angle setting:

[0088]

[0089] Rotation matrix calculation:

[0090]

[0091] Rotation of the lesion area:

[0092]

[0093] Among them, W m and H mRespectively represent the width and height of the IR image; R x and R y Respectively represent the horizontal and vertical coordinates of the rotation center of the lesion area; M R represents the rotation matrix; θ R is the rotation angle; R N is the maximum total number of rotations, and its value is specified by the operator before the algorithm is executed; r n is the number of times the current rotation is performed; (i, j) is the coordinate of the point to be rotated; (i', j') is the coordinate of the point after rotation.

[0094] In S3, the centroid of the lesion is located:

[0095] The morphology of the mid-plasma lesions in different patients is quite different. The mid-plasma lesion area is an irregular shape. Therefore, the centroid position of the mid-plasma lesion area is determined according to the following method of locating the centroid of an irregular geometric plane:

[0096]

[0097] in, and Respectively represent the abscissa and ordinate of the centroid of the mid-plasma lesion area; S A Indicates mid-cytoplasmic lesion area; x l and l S A The horizontal and vertical coordinates of any point in the.

[0098] Rectangular frame boundary positioning:

[0099]

[0100] Among them, I IR represents the IR image of the patient, whose size is W m ×H m , (i, j) is the coordinate of the pixel in the image; L up and L up_X are the candidate value and final value of the upper boundary of the rectangular box; L down and L down_X are the candidate value and final value of the lower boundary of the rectangular box respectively; L left and L left_Y are the candidate value and final value of the left boundary of the rectangular box; L right and L right_Y They are the candidate value and final value of the right boundary of the rectangular box respectively.

[0101] In S4, a corresponding algorithm is designed according to the uniform distribution rule, and uniform filling of the light spot is achieved by calculating the center position of the light spot. The calculation process of the light spot center at the boundary of the rectangular frame and the light spot center inside the rectangular frame is as follows:

[0102] Center of the light spot inside the rectangular frame:

[0103]

[0104] The center of the light spot at the border of the rectangular frame:

[0105]

[0106] Among them, (X c ,Y c )and Respectively represent the current spot center coordinates and the previous spot center coordinates; n x and n y It is the label variable in the program loop process; R L and D S They represent the spot radius variable and the spot spacing variable respectively.

[0107] In S5, the specific design of the restricted area spot removal algorithm is performed according to the laser spot avoidance rule. The process is shown as follows:

[0108] Spot removal in non-lesion areas:

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] in, and Respectively represent the rotation angle θ R The binary image of the lesion in the plasma and the initial filling image of the corresponding spot at that time; a1, a2, a3, and a4 represent marker variables, which have different values ​​and are used for Boolean operations; Express and The calculation result after the addition operation is performed; I plate Represents the laser spot template, whose size is N s ×N s ; N g Indicates the total number of initial fills of the light spot, (X c (g),Y c (g)) is the center coordinate of the g-th light spot; IP (g) indicates I plate and The dot product of the pixels at the corresponding position in ; 1{·} is the indicator function, which outputs 1 when the internal condition is met; and Respectively represent the statistical values ​​under the corresponding conditions; (X c_new (g),Y c_new (g)) represents the center coordinate of the gth spot among the remaining spots after removing the spots in the non-mesoplasmic lesion area;

[0116] Spot removal in thick blood vessel area:

[0117]

[0118] in, and Respectively represent the rotation angle θ R The binary image of blood vessels and the image based on (X c_new (g),Y c_new ( g)) The spot filling image of the mid-plasma lesion area; Express and The calculation result after the addition operation; N g0 It represents the total number of remaining spots after removing the spots in the non-mesoplasmic lesion area, (X c_new (g0),Y c_new (g0)) is the center coordinate of the g0th spot in the mid-plasma lesion area; P0 (g0) represents I plate and The dot product of the pixels at corresponding positions in ; and Respectively represent the statistical values ​​under the corresponding conditions; It represents the center coordinate of the g0th spot among the remaining spots after removing the intravascular spots in the mid-plasma lesion area;

[0119] Macular spot removal:

[0120]

[0121]

[0122] in, and Respectively represent the rotation angle θ R The binary image of the macular area and the The spot filling image of the mid-plasma lesion area; Express and The calculation result after the addition operation; Ng1 It indicates the total number of remaining spots after removing the intravascular spots in the mid-plasma lesion area. is the center coordinate of the g1th spot in the mid-plasma lesion area; I P1 (g1) indicates I plate and The dot product of the pixels at corresponding positions in ; and Respectively represent the statistical values ​​under the corresponding conditions; It represents the center coordinate of the g1th spot among the remaining spots after removing the spot in the macular area of ​​the lesion.

[0123] This embodiment adopts different parameter settings, and the adaptive filling method can achieve various laser spot filling effects, and can quickly realize the design of multiple spot filling schemes for different mesoplasm lesion areas or the same mesoplasm lesion area, while improving the efficiency of spot filling, and also providing multiple references for doctors to formulate optimized spot filling schemes. S , rotation angle θ R , spot radius R L , spot spacing D S Achieve a variety of spot filling effects. The following are the spot filling results based on different samples and different rotation angles θ R and spot radius R L The yellow circular spot is the laser spot, the cyan circular part is the forbidden area of ​​the macula, the rest of the cyan part is the thick blood vessel area, and the red curve is the boundary of the mid-secular lesion area.

[0124] (1) Spot filling results based on different samples

[0125] The spot radius R L and spot spacing D S Set them to 5 and 7 respectively, and select θ R Three filling schemes with values ​​of 0°, 160°, and 320° are used as examples. Figure 8 As shown in the figure. From the summary, the proposed algorithm can complete the spot filling target on different samples, and the performance is relatively consistent. It avoids the forbidden area in the middle plasma lesion area well, which shows that the proposed algorithm can effectively achieve the laser spot filling task in different middle plasma lesion areas. It can automatically complete the feasibility judgment of spot arrangement according to the morphological characteristics such as the boundary change and size of the lesion, and combine the position information of the thick blood vessel area and the forbidden area of ​​the macula in the middle plasma lesion area, and adaptively fill the spot. In addition, by comparing P r The value is known, based on the same θ R P of different samples of values r There are some differences between the values. The same sample has different R Pr There are also differences in the values, indicating that the spot filling schemes for the mid-plasma lesion area of ​​different patients may be inconsistent due to the differences in the mid-plasma lesion area, and there are also multiple options for the spot filling schemes for the mid-plasma lesion area of ​​the same patient.

[0126] (2) Based on different θ R and R L The spot filling result

[0127] The spot spacing D S Set to 4 pixels, and then, by setting different θ R Value and R L The corresponding spot filling solution is obtained. Fig. 9 As shown. At a fixed θ R Under the condition of different R L The spot filling results corresponding to the values ​​are obviously different. On the one hand, the P of each filling scheme is r There are obvious differences in the values. Within the range of the spot radius setting, P r The value increases with R L On the other hand, under different spot radius conditions, the spot distribution in each spot filling scheme is somewhat different, for example, the spot distribution near the same blood vessel area and the macular forbidden area is not consistent; setting the same R L When the value is different, R The spot filling results corresponding to the value are also different. The above observations show that when the spot spacing D is fixed S Under the premise of setting different θ R Value and R L The value has a certain degree of influence on the spot filling effect of the proposed algorithm. In practical applications, by setting different parameter combinations, doctors can obtain different filling schemes, and then make the final scheme selection based on the actual situation.

[0128] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus, characterized by: Design laser spot filling rules to provide a basis for the detailed design of the laser spot adaptive filling algorithm. The laser spot filling rules include spot uniform distribution rules, restricted area spot avoidance rules, and spot optimization filling rules. Uniform distribution rule of light spots: by setting different light spot spacing distances, different layout templates are obtained, thereby achieving different laser spot filling results; the light spot spacing in the horizontal and vertical directions is set to the same distance; Avoidance rules for restricted area spots: set a rectangular frame around the mesoplasma lesion area and divide it into lesion area, non-lesion area, thick blood vessel segment in the mesoplasma lesion area, and macular area; then, perform preliminary filling of laser spots according to the spot uniform distribution rule; use Boolean operations to determine whether the laser spot intersects with the above areas, remove the intersection area, and obtain the filling result; Spot optimization filling rule: according to the initial lesion area of ​​the patient, fill the laser spot according to the spot uniform distribution rule and the forbidden area spot avoidance rule; then rotate the lesion area around the selected axis at the set angle to obtain the rotated lesion area, and fill the laser spot again according to the uniform distribution rule; obtain the final spot center, that is, the spot position, through reverse rotation and spot avoidance rule; According to the laser spot filling rules, the laser spot adaptive filling method is specifically designed, including a rectangular frame positioning module, a spot center calculation module, a lesion area rotation module, and a restricted area spot removal module; the method automatically completes the feasibility judgment of laser spot arrangement according to the lesion boundary position, the position of the thick blood vessels in the mid-plasma lesion area, and the position of the macular area, and realizes the adaptive filling goal of the laser spot in the mid-plasma lesion area; According to the spot optimization filling rule, the corresponding laser spot adaptive filling algorithm is designed. The specific design steps are as follows: S1. Input IR image, mark the thick blood vessel segment, macular forbidden area and the boundary of mid-plasma lesion area; S2, lesion area rotation module, used for rotation center calculation, rotation angle setting, rotation matrix calculation and lesion area rotation, wherein the forward rotation angle is calculated according to the provided formula, the reverse rotation angle is the negative number of the forward rotation angle, and the forward and reverse rotation angles are substituted into the rotation matrix calculation formula to obtain the forward and reverse rotation matrices respectively; S3, rectangular frame positioning module, used for lesion centroid positioning and rectangular frame boundary positioning; S4, a light spot center calculation module, used to calculate the light spot center inside the rectangular frame and the light spot center at the border of the rectangular frame; S5, restricted area spot removal module, used for spot removal in non-lesion area, thick blood vessel area and macular area.

2. The method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus according to claim 1, characterized in that: During the filling process, different laser spot arrangement results are obtained by setting multiple rotation angles, based on the ratio of the total area of ​​the laser spot in the lesion area to the area of ​​the lesion area. The specific formula is as follows: P r =N p ×S ap / S L ; Among them, P r Indicates ratio; N p Indicates the number of laser spots arranged in the lesion area; S ap Represents the area of ​​a single laser spot; S L is the area of ​​the mid-plasma lesion.

3. The method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus according to claim 1, characterized in that: In S2, the rotation center is calculated: Rotation angle setting: Rotation matrix calculation: Rotation of the lesion area: Among them, W m and H m Respectively represent the width and height of the IR image; R x and R y Respectively represent the horizontal and vertical coordinates of the rotation center of the lesion area; M R represents the rotation matrix; θ R is the rotation angle; R N is the maximum total number of rotations, and its value is specified by the operator before the algorithm is executed; r n is the number of times the current rotation is performed; (i, j) is the coordinate of the point to be rotated; (i', j') is the coordinate of the point after rotation.

4. The method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus according to claim 1, characterized in that: In S3, the centroid of the lesion is located: The centroid location method of irregular geometric plane is used to determine the centroid position of the mid-plasma lesion area: in, and Respectively represent the abscissa and ordinate of the centroid of the mid-plasma lesion area; S A Indicates mid-cytoplasmic lesion area; x l and l S A The horizontal and vertical coordinates of any point in the Rectangular frame boundary positioning: Among them, I IR represents the IR image of the patient, whose size is W m ×H m , (i, j) is the coordinate of the pixel in the image; L up and L up_X are the candidate value and final value of the upper boundary of the rectangular box; L down and L down_X are the candidate value and final value of the lower boundary of the rectangular box respectively; L left and L left_Y are the candidate value and final value of the left boundary of the rectangular box; L right and L right_Y They are the candidate value and final value of the right boundary of the rectangular box respectively.

5. The method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus according to claim 1, characterized in that: In S4, a corresponding algorithm is designed according to the uniform distribution rule, and uniform filling of the light spot is achieved by calculating the center position of the light spot. The calculation process of the light spot center at the boundary of the rectangular frame and the light spot center inside the rectangular frame is as follows: Center of the light spot inside the rectangular frame: The center of the light spot at the border of the rectangular frame: Among them, (X c ,Y c ) and (X c nx-1 ,Y c nx-1 ) represent the current spot center coordinates and the previous spot center coordinates respectively; n x and n y It is the label variable in the program loop process; R L and D S They represent the spot radius variable and the spot spacing variable respectively.

6. The method for adaptively filling laser spots in the mid-plasma lesion area of ​​the fundus according to claim 1, characterized in that: In S5, the restricted area spot removal algorithm is specifically designed according to the laser spot avoidance rule. The process is shown as follows: Spot removal in non-lesion areas: in, and Respectively represent the rotation angle θ R The binary image of the lesion in the plasma and the initial filling image of the corresponding spot at that time; a1, a2, a3, and a4 represent marker variables, which have different values ​​and are used for Boolean operations; Express and The calculation result after the addition operation is performed; I plate Represents the laser spot template, whose size is N s ×N s ; N g Indicates the total number of initial fills of the light spot, (X c (g),Y c (g)) is the center coordinate of the g-th light spot; I P (g) indicates I plate and The dot product of the pixels at corresponding positions in ; and Respectively represent the statistical values ​​under the corresponding conditions; (X c_new (g),Y c_new (g)) represents the center coordinate of the gth spot among the remaining spots after removing the spots in the non-mesoplasmic lesion area; Spot removal in thick blood vessel area: in, and Respectively represent the rotation angle θ R The binary image of blood vessels and the image based on (X c_new (g),Y c_new (g)) The spot filling image of the mid-plasma lesion area; Express and The calculation result after the addition operation; N g0 It represents the total number of remaining spots after removing the spots in the non-mesoplasmic lesion area, (X c_new (g0),Y c_new (g0)) is the center coordinate of the g0th spot in the mid-plasma lesion area; P0 (g0) represents I plate and The dot product of the pixels at corresponding positions in ; and Respectively represent the statistical values ​​under the corresponding conditions; It represents the center coordinate of the g0th spot among the remaining spots after removing the intravascular spots in the mid-plasma lesion area; Macular spot removal: in, and Respectively represent the rotation angle θ R The binary image of the macular area and the The spot filling image of the mid-plasma lesion area; Express and The calculation result after the addition operation; N g1 It indicates the total number of remaining spots after removing the intravascular spots in the mid-plasma lesion area. is the center coordinate of the g1th spot in the mid-plasma lesion area; I P1 (g1) indicates I plate and The dot product of the pixels at corresponding positions in ; and Respectively represent the statistical values ​​under the corresponding conditions; It represents the center coordinate of the g1th spot among the remaining spots after removing the spot in the macular area of ​​the lesion.

Images