A system and method for calculating femoral head alpha angle, offset and control point

Abstract

The present invention relates to the technical field of medical image processing, and provides a system for calculating the alpha angle, offset and control points of the femoral head, comprising: an image preprocessing module, for acquiring an input image to be calculated, performing image preprocessing on the input image, and obtaining an operation image; a control point calculation module, for calculating auxiliary points and auxiliary straight lines on the operation image, and calculating control points based on the obtained auxiliary points and auxiliary straight lines; a parameter calculation module, for calculating the alpha angle and offset parameters based on the calculated control points. The above technical scheme can realize the automatic calculation of the alpha angle, offset parameters, control points and other parameters required for preoperative planning, and provides a method for automatically calculating pre-parameters for preoperative planning. At the same time, there is no need to rely too much on manpower, and there is no need to collect a large number of labeled samples for neural network training.

Description

Technical Field

[0001] The present invention relates to the technical field of medical image processing, and in particular to a system and method for calculating femoral head alpha angle, offset and control points. Background Art

[0002] In image-guided minimally invasive hip arthroscopy, after the binary image of the femur is obtained after the femur and acetabulum are separated, the long axis of the femur is calculated as needed, and the femoral head (including the center and radius of the femoral head) is identified, so as to perform preoperative planning. Before performing preoperative planning, an important step is to calculate some parameters that have a necessary relationship with it, such as the alpha angle, offset, and control points. Among them, the alpha angle is an indicator of the sphericity of the femoral head when judging femoroacetabular impingement syndrome. The sphericity of the femoral head and the eccentricity of the femoral head and neck can be evaluated based on the alpha angle. The offset is the eccentricity of the femur. The eccentricity is specifically the vertical distance from the center of rotation of the femoral head to the long axis of the femur.

[0003] There are two common methods for calculating the alpha angle, offset, and control points. One is to have the doctor manually specify points and measure the relevant parameters based on the manually specified points; the other is to use the neural network method, where the doctor pre-marks the feature points, trains a model to identify the feature points, and then uses the model to identify the feature points to calculate the relevant parameters.

[0004] However, the problem with the above approach is that it takes a lot of effort and time to achieve relatively good results. For example, manual labeling by doctors relies too much on manpower, while the method of training neural networks requires collecting labels and considering the distribution of samples, which takes a long development cycle. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a system and method for calculating the alpha angle, offset and control point of the femoral head, which has the characteristics of automating parameter calculation and saving manpower and development time.

[0006] The above-mentioned object of the present invention is achieved through the following technical solutions:

[0007] A system for calculating femoral head alpha angle, offset and control points, comprising:

[0008] A memory, which stores the acquired input image of the femoral head alpha angle, offset parameter and control point to be calculated, the preprocessed operation image, and the calculated control point, alpha angle and offset parameter;

[0009] An image acquisition device, used for acquiring the input image of the femoral head alpha angle, the offset parameter and the control point to be calculated before image-guided hip arthroscopy minimally invasive surgery;

[0010] A processor is used to calculate parameters including the alpha angle, the offset parameter and the control point for preoperative planning before performing the preoperative planning of the image-guided hip arthroscopy minimally invasive surgery, so as to perform planning including calculating the long axis of the femur and identifying the femoral head according to the calculated parameters during preoperative planning, and calculate the control point, the alpha angle and the offset parameter through the following modules:

[0011] An image preprocessing module, used for acquiring the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery with parameters to be calculated, and performing image preprocessing on the input image to obtain the operation image;

[0012] A control point calculation module, used to calculate auxiliary points and auxiliary straight lines on the operation image, and calculate control points based on the obtained auxiliary points and auxiliary straight lines;

[0013] A parameter calculation module is used to calculate the alpha angle and the offset parameter according to the calculated control points.

[0014] Furthermore, in the image preprocessing module, the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery with parameters to be calculated is obtained, and image preprocessing is performed on the input image to obtain the operation image, specifically:

[0015] The input image for preoperative planning of image-guided hip arthroscopy minimally invasive surgery for which parameters are to be calculated is binarized, and the binarization is performed using a combination of hole filling and closing operations, wherein the hole filling is to fill holes in the original input image to preliminarily eliminate holes in the original input image, and the closing operation is to further eliminate holes in the original input image, specifically including:

[0016] A preset threshold is set according to the image characteristics of the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery, and the input image is binarized according to the preset threshold to divide the input image into a target area including a femur and an acetabulum, and a background area excluding the femur and the acetabulum;

[0017] Scanning the input image after the binarization process pixel by pixel to find holes that do not belong to the target area, and for each hole, using a dilation kernel to perform a dilation operation on the hole, and then performing a logical OR operation on the dilated image and the original input image to obtain a filled image, wherein the dilation kernel is a structural element used in morphological image processing and is used to perform a dilation operation;

[0018] A closing operation is performed on the filled image, wherein the closing operation includes an erosion operation and a dilation operation, wherein the erosion operation is performed on the filled image to remove the small target area or noise in the filled image, and the erosion operation is performed using structural elements of different shapes and sizes according to the characteristics and needs of the image, and the dilation operation is performed on the eroded image to restore the eroded target area in the image, and finally the operation image is obtained.

[0019] Furthermore, in the control point calculation module, the auxiliary points and the auxiliary straight lines are calculated on the operation image, specifically:

[0020] The straight line where the long axis of the femur is located is used as the auxiliary straight line, and a point on the auxiliary straight line where the long axis of the femoral neck exceeds the radius of the femoral head circle by a preset specified distance specified by the user is obtained as the auxiliary point;

[0021] Wherein, taking the straight line where the long axis of the femur is located as the auxiliary straight line specifically includes:

[0022] Using edge detection algorithms including Sobel and Canny to perform edge detection on the operation image to find the rough outline of the femur;

[0023] Based on edge detection, an algorithm including a contour detection function in the OpenCV image processing library is used to find the contour of the femur in the operation image;

[0024] Using an ellipse fitting algorithm to fit the ellipse shape of the femur, extracting the long axis parameters of the femur including the center point coordinates, the long axis length, the short axis length and the rotation angle from the fitted ellipse;

[0025] The long axis parameters are used to draw a straight line where the long axis of the femur is located, and the drawn straight line is superimposed on the original operation image to obtain the auxiliary straight line.

[0026] Furthermore, in the control point calculation module, a point at which the long axis of the femoral neck specified by the user exceeds the radius of the femoral head circle by a preset specified distance is obtained on the auxiliary straight line as the auxiliary point, specifically:

[0027] Obtain any two different endpoints on the long axis of the femur and calculate the straight line equation of the long axis of the femur;

[0028] On the straight line equation, according to the preset specified distance that the long axis of the femoral neck exceeds the radius of the femoral head circle, the basic principle of collinearity of the straight line equation is used to solve it and obtain the auxiliary point.

[0029] Furthermore, in the control point calculation module, the control point is calculated according to the obtained auxiliary point and the auxiliary straight line, specifically:

[0030] A straight line perpendicular to the auxiliary straight line is made through the auxiliary point, with the direction pointing to the image origin as the positive direction, and the intersection of the positive direction of the straight line and the edge of the femur is obtained as a fourth control point, wherein the fourth control point is a point in the positive direction of the straight line, the pixel value of the fourth control point is 255, and the pixel value of the next point of the fourth control point is 0;

[0031] Draw a straight line perpendicular to the auxiliary straight line through the center of the femoral head, with the direction pointing to the image origin as the positive direction, and obtain the intersection of the positive direction of the straight line and the edge of the femur as the first control point, wherein the first control point is a point in the positive direction of the straight line, the pixel value of the first control point is 255, and the pixel value of the next point of the fourth control point is 0;

[0032] Find a point from the first control point in the direction of the femoral neck as the second control point, and the second control point satisfies that the second control point is on the circumference of the femoral head circle, and the pixel values ​​within the range of 5 pixels with the second control point as the center are all 255;

[0033] The user sets a standard ALPHA angle, and the intersection of another side of the standard ALPHA angle on the same side as the first control point except the long axis of the femur and the circumference of the femoral head circle is obtained as the third control point.

[0034] Furthermore, in the parameter calculation module, the alpha angle is calculated as follows:

[0035] Taking the center of the femoral head circle as the vertex, calculate the angle between the line connecting the second control point and the vertex and the long axis of the femur as the alpha angle.

[0036] Further, in the parameter calculation module, the offset parameter is calculated, specifically:

[0037] The offset parameter is obtained by subtracting the vertical distance from the second control point to the long axis of the femur from the radius of the femoral head circle.

[0038] A method for calculating the femoral head alpha angle, offset and control point using the system for calculating the femoral head alpha angle, offset and control point as described above, comprising:

[0039] S1: obtaining an input image to be calculated, performing image preprocessing on the input image, and obtaining an operation image;

[0040] S2: Calculating auxiliary points and auxiliary straight lines on the operation image, and calculating control points based on the obtained auxiliary points and auxiliary straight lines;

[0041] S3: Calculate the alpha angle and offset parameters according to the calculated control points.

[0042] A computer device comprises a memory and one or more processors, wherein the memory stores computer codes, and when the computer codes are executed by the one or more processors, the one or more processors execute the above method.

[0043] A computer-readable storage medium stores computer codes. When the computer codes are executed, the above method is executed.

[0044] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0045] (1) A system for calculating the alpha angle, offset and control points of the femoral head is provided, comprising: a memory for storing an input image of the femoral head alpha angle, offset parameters and control points to be calculated, the preprocessed operation image, and the calculated control points, the alpha angle and the offset parameters; an image acquisition device for acquiring the input image of the femoral head alpha angle, offset parameters and control points to be calculated before image-guided hip arthroscopy minimally invasive surgery; a processor for calculating the alpha angle, offset parameters and control points used for preoperative planning before performing preoperative planning of the image-guided hip arthroscopy minimally invasive surgery. and the parameters including the control points, so that during preoperative planning, planning including calculating the long axis of the femur and identifying the femoral head is performed according to the calculated parameters, and the control points, the alpha angle and the offset parameters are calculated by the following modules: an image preprocessing module, which is used to obtain the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery with the parameters to be calculated, and perform image preprocessing on the input image to obtain the operation image; a control point calculation module, which is used to calculate auxiliary points and auxiliary straight lines on the operation image, and calculate control points based on the obtained auxiliary points and auxiliary straight lines; a parameter calculation module, which is used to calculate the alpha angle and the offset parameters based on the calculated control points. The above technical solution can realize the automatic calculation of the parameters required for preoperative planning, such as the alpha angle, offset parameters and control points, and provides a solution for automatically calculating the pre-parameters for preoperative planning.

[0046] (2) The solution provided by the present invention does not need to rely too much on manpower, and does not need to collect a large number of labeled samples for neural network training. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of the processor execution in the system for calculating the femoral head alpha angle, offset and control point of the present invention;

[0048] Figure 2 A schematic diagram of calculating auxiliary points in the system for calculating the femoral head alpha angle, offset and control point of the present invention;

[0049] Figure 3 A schematic diagram of the result of calculating auxiliary points by the system for calculating the femoral head alpha angle, offset and control point of the present invention;

[0050] Figure 4 A schematic diagram of the result of calculating the fourth control point in the system for calculating the femoral head alpha angle, offset and control point of the present invention;

[0051] Figure 5 A schematic diagram of the result of calculating the first control point in the system for calculating the femoral head alpha angle, offset and control point of the present invention;

[0052] Figure 6 A schematic diagram of the result of calculating the second control point and the alpha angle in the system for calculating the femoral head alpha angle, offset and control point of the present invention;

[0053] Figure 7 A schematic diagram of the result of calculating the third control point in the system for calculating the femoral head alpha angle, offset and control point of the present invention;

[0054] Figure 8 A schematic diagram of the results of calculating offset parameters in the system for calculating the femoral head alpha angle, offset and control point of the present invention;

[0055] Fig. 9 The present invention is an overall flow chart of the method for calculating the femoral head alpha angle, offset and control points. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0058] First embodiment

[0059] like Figure 1As shown, this embodiment provides a system for calculating the alpha angle, offset and control points of the femoral head. After obtaining the input image, binarization preprocessing is performed, wherein the binarization can be performed by the user in combination with hole filling and closing operations to obtain an operation image for operation; on the basis of the operation image, auxiliary points and auxiliary lines are calculated according to known input quantities such as the ALPHA angle set by the user, and control point parameters are calculated according to the obtained auxiliary points; alpha angle and offset parameters are calculated according to the calculated control points and known quantities such as the long axis of the femur.

[0060] The system for calculating the femoral head alpha angle, offset and control point implemented in this embodiment specifically includes:

[0061] A memory, which stores the acquired input image of the femoral head alpha angle, offset parameter and control point to be calculated, the preprocessed operation image, and the calculated control point, alpha angle and offset parameter;

[0062] An image acquisition device, used for acquiring the input image of the femoral head alpha angle, the offset parameter and the control point to be calculated before image-guided hip arthroscopy minimally invasive surgery;

[0063] A processor is used to calculate parameters including the alpha angle, the offset parameter and the control point for preoperative planning before performing the preoperative planning of the image-guided hip arthroscopy minimally invasive surgery, so as to perform planning including calculating the long axis of the femur and identifying the femoral head according to the calculated parameters during preoperative planning, and calculate the control point, the alpha angle and the offset parameter through the following modules:

[0064] The image preprocessing module is used to obtain the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery with the parameters to be calculated, and perform image preprocessing on the input image to obtain the operation image, specifically:

[0065] The input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery to be calculated is binarized, and the binarization is performed by a morphological filling method that combines hole filling and closing operations to provide stability for the subsequent calculation of auxiliary points and control points. The hole filling is to fill the holes in the original input image to preliminarily eliminate the holes in the original input image, and the closing operation is used to further eliminate the holes in the original input image. In this embodiment, the size of the kernel of the closing operation is selected by the user, and the default is 25, which specifically includes:

[0066] A preset threshold is set according to the image characteristics of the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery, and the input image is binarized according to the preset threshold to divide the input image into a target area including a femur and an acetabulum, and a background area excluding the femur and the acetabulum;

[0067] Scanning the input image after the binarization process pixel by pixel to find holes that do not belong to the target area, and for each hole, using a dilation kernel to perform a dilation operation on the hole, and then performing a logical OR operation on the dilated image and the original input image to obtain a filled image, wherein the dilation kernel is a structural element used in morphological image processing and is used to perform a dilation operation;

[0068] A closing operation is performed on the filled image, wherein the closing operation includes an erosion operation and a dilation operation, wherein the erosion operation is performed on the filled image to remove the small target area or noise in the filled image, and the erosion operation is performed using structural elements of different shapes and sizes according to the characteristics and needs of the image, and the dilation operation is performed on the eroded image to restore the eroded target area in the image, and finally the operation image is obtained.

[0069] It should be noted that binarization of the input image and binarization by a morphological filling method combining hole filling and closing operations are not the only processing methods for the input image in the present invention. Any method that can clearly separate the femur from the image background can be applied to the present invention.

[0070] The control point calculation module is used to calculate auxiliary points and auxiliary straight lines on the operation image, and calculate control points according to the obtained auxiliary points and auxiliary straight lines.

[0071] (1) Calculating the auxiliary points and the auxiliary straight lines on the operation image

[0072] like Figure 2 As shown, the straight line where the long axis of the femur is located is used as the auxiliary straight line, and a point where the long axis of the femoral neck exceeds the radius of the femoral head circle by a preset specified distance specified by the user is obtained on the auxiliary straight line as the auxiliary point (the obtained auxiliary point is as shown in FIG. Figure 3 shown).

[0073] Wherein, taking the straight line where the long axis of the femur is located as the auxiliary straight line specifically includes:

[0074] Using edge detection algorithms including Sobel and Canny to perform edge detection on the operation image to find the rough outline of the femur;

[0075] Based on edge detection, an algorithm including a contour detection function in the OpenCV image processing library is used to find the contour of the femur in the operation image;

[0076] Using an ellipse fitting algorithm to fit the ellipse shape of the femur, extracting the long axis parameters of the femur including the center point coordinates, the long axis length, the short axis length and the rotation angle from the fitted ellipse;

[0077] The long axis parameters are used to draw a straight line where the long axis of the femur is located, and the drawn straight line is superimposed on the original operation image to obtain the auxiliary straight line.

[0078] Among them, a point specified by the user on the auxiliary straight line where the long axis of the femoral neck exceeds the radius of the femoral head by a preset specified distance is obtained as the auxiliary point, specifically: any two different endpoints on the long axis of the femur (preferably one of the endpoints and the center of the femoral head) are obtained, and the straight line equation of the long axis of the femur (also known as the slope of the straight line) is calculated; on the straight line equation, according to the set long axis of the femoral neck exceeds the radius of the femoral head by a preset specified distance, the basic principle of collinearity of the straight line equation is used to solve the problem, and the auxiliary point pt5_hat is obtained.

[0079] (2) Calculating the control point based on the obtained auxiliary point and the auxiliary straight line

[0080] Calculate four control points respectively. The first control point is the control point with 90 degrees to the alpha angle. The second control point is the control point that constitutes the alpha angle. The third control point is the control point that constitutes the set standard alpha angle. The fourth control point is the point corresponding to the upper edge of the femoral neck where the long axis of the femoral neck exceeds the specified distance of the femoral head circle radius. The following are the specific calculation steps for the four control points:

[0081] like Figure 4 As shown, a straight line perpendicular to the auxiliary straight line is made through the auxiliary point pt5_hat, with the direction pointing to the image origin as the positive direction, and the intersection of the positive direction of the straight line and the edge of the femur is obtained as the fourth control point ctr_pt4_before, wherein the fourth control point is a point in the positive direction of the straight line, the pixel value of the fourth control point is 255, and the pixel value of the next point of the fourth control point is 0;

[0082] like Figure 5As shown, a straight line perpendicular to the auxiliary straight line is made through the center of the femoral head, with the direction pointing to the origin of the image as the positive direction, and the intersection of the positive direction of the straight line and the edge of the femur is obtained as the first control point ctr_pt1_before, wherein the first control point is a point in the positive direction of the straight line, the pixel value of the first control point is 255, and the pixel value of the next point of the fourth control point is 0;

[0083] like Figure 6 As shown, a point is found from the first control point in the direction of the femoral neck as the second control point ctr_pt2_before, and the second control point satisfies that the second control point is on the circumference of the femoral head circle, and at the same time, the pixel values ​​within the range of 5 pixels with the second control point as the center are all 255;

[0084] like Figure 7 As shown, the user sets the standard ALPHA angle, and obtains the intersection of the other side of the standard ALPHA angle on the same side as the first control point except the long axis of the femur and the circumference of the femoral head circle as the third control point ctr_pt3_before. Another way to obtain the third control point is to reversely deduce the third point constituting the ALPHA angle based on the known center of the femoral head on the long axis of the femur and the other endpoint, and the standard ALPHA angle set by the user. This point is not unique. By setting the constraint condition to be on the same side as the first control point, a unique solution is obtained, that is, the third control point is calculated.

[0085] The parameter calculation module is used to calculate the alpha angle and offset parameters according to the calculated control points.

[0086] (1) Calculate the alpha angle

[0087] Combination Figure 6 , taking the center of the femoral head circle as the vertex, calculating the angle between the line connecting the second control point and the vertex and the long axis of the femur as the alpha angle.

[0088] Or the alpha angle is calculated by using the cosine theorem with the center of the femoral head circle as the vertex, an end point on the long axis of the femur and the second control point, that is:

[0089] a 2 =b 2 +c 2 -2·b·c·cosA

[0090] Among them, a is the distance between an endpoint on the long axis of the femur and the second control point, b and c are the distances from the vertex to an endpoint on the long axis of the femur and the second control point, and the obtained A is the alpha angle.

[0091] (2) Calculate the offset parameter

[0092] like Figure 8 As shown, the radius of the femoral head circle minus the vertical distance from the second control point to the long axis of the femur is used as the offset parameter.

[0093] Second embodiment

[0094] like Fig. 9 As shown, this embodiment provides a method for calculating the femoral head alpha angle, offset and control point using the system for calculating the femoral head alpha angle, offset and control point in the first embodiment, including:

[0095] S1: obtaining an input image to be calculated, performing image preprocessing on the input image, and obtaining an operation image;

[0096] S2: Calculating auxiliary points and auxiliary straight lines on the operation image, and calculating control points based on the obtained auxiliary points and auxiliary straight lines;

[0097] S3: Calculate the alpha angle and offset parameters according to the calculated control points.

[0098] A computer-readable storage medium stores a computer code. When the computer code is executed, the above method is executed. A person skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium. The storage medium can include: a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc.

[0099] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

[0100] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A system for calculating femoral head alpha angle, offset and control point, characterized in that: include: A memory, which stores the acquired input image of the femoral head alpha angle, offset parameter and control point to be calculated, the preprocessed operation image, and the calculated control point, alpha angle and offset parameter; An image acquisition device, used for acquiring the input image of the femoral head alpha angle, the offset parameter and the control point to be calculated before image-guided hip arthroscopy minimally invasive surgery; A processor is used to calculate parameters including the alpha angle, the offset parameter and the control point for preoperative planning before performing the preoperative planning of the image-guided hip arthroscopy minimally invasive surgery, so as to perform planning including calculating the long axis of the femur and identifying the femoral head according to the calculated parameters during preoperative planning, and calculate the control point, the alpha angle and the offset parameter through the following modules: An image preprocessing module, used for acquiring the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery with parameters to be calculated, and performing image preprocessing on the input image to obtain the operation image; A control point calculation module is used to calculate auxiliary points and auxiliary straight lines on the operation image, take the straight line where the long axis of the femur is located as the auxiliary straight line, obtain a point on the auxiliary straight line where the long axis of the femoral neck exceeds the radius of the femoral head circle by a preset specified distance, as the auxiliary point, and calculate the control point based on the obtained auxiliary point and the auxiliary straight line; A parameter calculation module is used to calculate the alpha angle and the offset parameter according to the calculated control points.

2. The system for calculating femoral head alpha angle, offset and control point according to claim 1, characterized in that: In the image preprocessing module, the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery with parameters to be calculated is obtained, and image preprocessing is performed on the input image to obtain the operation image, specifically: The input image for preoperative planning of image-guided hip arthroscopy minimally invasive surgery for which parameters are to be calculated is binarized, and the binarization is performed using a combination of hole filling and closing operations, wherein the hole filling is to fill holes in the original input image to preliminarily eliminate holes in the original input image, and the closing operation is to further eliminate holes in the original input image, specifically including: A preset threshold is set according to the image characteristics of the input image for preoperative planning of the image-guided hip arthroscopy minimally invasive surgery, and the input image is binarized according to the preset threshold to divide the input image into a target area including a femur and an acetabulum, and a background area excluding the femur and the acetabulum; Scanning the input image after the binarization process pixel by pixel to find holes that do not belong to the target area, and for each hole, using a dilation kernel to perform a dilation operation on the hole, and then performing a logical OR operation on the dilated image and the original input image to obtain a filled image, wherein the dilation kernel is a structural element used in morphological image processing and is used to perform a dilation operation; A closing operation is performed on the filled image, wherein the closing operation includes an erosion operation and a dilation operation, wherein the erosion operation is performed on the filled image to remove the small target area or noise in the filled image, and the erosion operation is performed using structural elements of different shapes and sizes according to the characteristics and needs of the image, and the dilation operation is performed on the eroded image to restore the eroded target area in the image, and finally the operation image is obtained.

3. The system for calculating femoral head alpha angle, offset and control point according to claim 1, characterized in that: In the control point calculation module, the auxiliary points and the auxiliary straight lines are calculated on the operation image, specifically: The straight line where the long axis of the femur is located is used as the auxiliary straight line, specifically including: Using edge detection algorithms including Sobel and Canny to perform edge detection on the operation image to find the rough outline of the femur; Based on edge detection, an algorithm including a contour detection function in the OpenCV image processing library is used to find the contour of the femur in the operation image; Using an ellipse fitting algorithm to fit the ellipse shape of the femur, extracting the long axis parameters of the femur including the center point coordinates, the long axis length, the short axis length and the rotation angle from the fitted ellipse; The long axis parameters are used to draw a straight line where the long axis of the femur is located, and the drawn straight line is superimposed on the original operation image to obtain the auxiliary straight line.

4. The system for calculating femoral head alpha angle, offset and control point according to claim 3, characterized in that: In the control point calculation module, a point at which the long axis of the femoral neck exceeds the radius of the femoral head circle by a preset specified distance specified by the user is obtained on the auxiliary straight line as the auxiliary point, specifically: Obtain any two different endpoints on the long axis of the femur and calculate the straight line equation of the long axis of the femur; On the straight line equation, according to the preset specified distance that the long axis of the femoral neck exceeds the radius of the femoral head circle, the basic principle of collinearity of the straight line equation is used to solve it and obtain the auxiliary point.

5. The system for calculating femoral head alpha angle, offset and control point according to claim 3, characterized in that: In the control point calculation module, the control point is calculated according to the obtained auxiliary point and the auxiliary straight line, specifically: A straight line perpendicular to the auxiliary straight line is made through the auxiliary point, with the direction pointing to the image origin as the positive direction, and the intersection of the positive direction of the straight line and the edge of the femur is obtained as a fourth control point, wherein the fourth control point is a point in the positive direction of the straight line, the pixel value of the fourth control point is 255, and the pixel value of the next point of the fourth control point is 0; Draw a straight line perpendicular to the auxiliary straight line through the center of the femoral head, with the direction pointing to the image origin as the positive direction, and obtain the intersection of the positive direction of the straight line and the edge of the femur as the first control point, wherein the first control point is a point in the positive direction of the straight line, the pixel value of the first control point is 255, and the pixel value of the next point of the fourth control point is 0; Find a point from the first control point in the direction of the femoral neck as the second control point, and the second control point satisfies that the second control point is on the circumference of the femoral head circle, and the pixel values ​​within the range of 5 pixels with the second control point as the center are all 255; The user sets a standard ALPHA angle, and the intersection of another side of the standard ALPHA angle on the same side as the first control point except the long axis of the femur and the circumference of the femoral head circle is obtained as the third control point.

6. The system for calculating femoral head alpha angle, offset and control point according to claim 5, characterized in that: In the parameter calculation module, the alpha angle is calculated as follows: Taking the center of the femoral head circle as the vertex, calculate the angle between the line connecting the second control point and the vertex and the long axis of the femur as the alpha angle.

7. The system for calculating femoral head alpha angle, offset and control point according to claim 5, characterized in that: In the parameter calculation module, the offset parameter is calculated, specifically: The offset parameter is obtained by subtracting the vertical distance from the second control point to the long axis of the femur from the radius of the femoral head circle.

8. A method for calculating the femoral head alpha angle, offset and control point using the system for calculating the femoral head alpha angle, offset and control point as described in any one of claims 1 to 7, characterized in that: include: S1: obtaining an input image to be calculated, performing image preprocessing on the input image, and obtaining an operation image; S2: Calculating auxiliary points and auxiliary straight lines on the operation image, and calculating control points based on the obtained auxiliary points and auxiliary straight lines; S3: Calculate the alpha angle and offset parameters according to the calculated control points.

9. A computer device comprising a memory and one or more processors, wherein the memory stores computer codes, and when the computer codes are executed by the one or more processors, the one or more processors execute the method according to any one of claims 8. 10 . A computer-readable storage medium storing a computer code, wherein when the computer code is executed, the method according to claim 8 is executed.

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