Spinal surgery screw placement path planning method and device and computer program product

Abstract

The embodiment of the invention is suitable for the technical field of computer-aided medical treatment, and provides a spinal surgery screw placement path planning method and device and a computer program product, and the method comprises the steps: obtaining a spinal image, and determining a spinal central axis based on the spinal image; determining a nail placement stop point according to the central axis of the spine; based on the screw placement stop points, a screw placement point candidate set is determined, and the screw placement point candidate set comprises a plurality of candidate screw placement points located on the spine transverse process; a candidate screw placement path formed by any candidate screw placement entry point and the screw placement stop point is determined; respectively calculating the distance from each bone surface edge point of the spine bone surface to each candidate screw placement path, and determining a screw placement point from the plurality of candidate screw placement points according to the distances; and planning a nail placement path based on the nail placement entry point and the nail placement stop point. By applying the method, the screw placement path of the spinal surgery can be automatically planned, and the accuracy and efficiency of screw placement path planning are improved.

Description

Technical Field

[0001] The embodiments of the present application belong to the field of computer-assisted medical technology, and in particular, relate to a spinal surgery nail placement path planning method, device and computer program product. Background Art

[0002] In spinal surgery, inserting screws into the corresponding segments or positions of the spine is one of the more common surgical operations. At present, the insertion of screws in spinal surgery requires doctors to evaluate the anatomical structure and pathological conditions of the spine through imaging examinations such as X-rays, computed tomography (CT) or magnetic resonance imaging (MRI) to determine the best position and angle for inserting the screws. For example, doctors can use CT images to plan the path of the inserted screws, determine the position, angle and depth of the inserted screws, and thus develop a detailed surgical plan. However, this method of using CT images for screw placement path planning requires the doctor to manually adjust the screw placement path in combination with the CT images, which is not only complicated and time-consuming to operate, but also easily affected by the doctor's subjective factors, leading to problems such as poor screw placement. Summary of the invention

[0003] In view of this, the embodiments of the present application provide a spinal surgery nail placement path planning method, device and computer program product, which are used to automatically plan the nail placement path of spinal surgery and improve the accuracy and efficiency of nail placement path planning.

[0004] A first aspect of an embodiment of the present application provides a spinal surgery nail placement path planning method, comprising: Acquire a spinal column image and determine a spinal column central axis based on the spinal column image; Determine the screw placement stop point according to the spinal axis; Based on the screw placement stop point, determining a set of candidate screw placement points, wherein the set of candidate screw placement points includes a plurality of candidate screw placement points located on the transverse processes of the spine; Respectively determine a candidate nail placement path formed by any of the candidate nail placement entry points and the nail placement end points; Calculating the distance from each edge point of the spinal bone surface to each of the candidate nail placement paths respectively, and determining a nail placement point from a plurality of the candidate nail placement points according to the distance; Based on the screw insertion point and the screw stop point, a screw insertion path is planned.

[0005] Optionally, acquiring a spinal column image and determining a spinal column central axis based on the spinal column image comprises: Acquiring a spinal column image and performing mirror processing on the spinal column image to generate a mirror image; Identifying a plurality of feature point pairs that match the spine image and the mirror image; The central axis of the spine is determined according to the plurality of feature point pairs.

[0006] Optionally, determining the spinal axis according to the plurality of feature point pairs comprises: Converting the plurality of feature point pairs into feature description points on the spinal image respectively, and calculating the angle between the straight line formed by each feature description point pair and the X-axis of the image coordinate system and the midpoint coordinates of each straight line; Determine the upper end point and the lower end point of the spine centerline according to the angle and the midpoint coordinates; The spinal column center axis is obtained by connecting the upper end point and the lower end point.

[0007] Optionally, determining the screw placement stop point according to the spine midline includes: Determine a vertebral reference point on the central axis of the spine, and determine the vertebral width based on the vertebral reference point; The screw placement stop point is determined by a preset ratio of the vertebral reference point offset from the vertebral width, and a line connecting the screw placement stop point and the vertebral reference point is perpendicular to the central axis of the spine.

[0008] Optionally, determining the vertebral width according to the vertebral reference point comprises: A straight line is drawn through the vertebral body reference point and is perpendicular to the central axis of the spine and intersects the spine bone surfaces on both sides; The vertebral width was calculated by calculating the distance between the intersection points on the spinal bone surfaces on both sides.

[0009] Optionally, the determining a set of candidate nail placement entry points based on the nail placement end point includes: Determine the range of inclination angles of the screws to be inserted; According to the screw placement stop point and the screw inclination angle range, multiple candidate screw placement points on the transverse process of the spine are determined.

[0010] Optionally, determining a nail insertion point from a plurality of candidate nail insertion points according to the distance includes: For any of the bone surface edge points, determining the minimum distance from the bone surface edge point to each of the candidate nail placement paths; The candidate screw insertion point corresponding to the maximum value among the minimum distances of the plurality of bone surface edge points is determined as the screw insertion point.

[0011] Optionally, planning a nail placement path based on the nail placement entry point and the nail placement end point includes: Connecting the screw insertion point and the screw stop point to obtain a first screw insertion path; The first nail placement path is offset along the first direction and the second direction respectively to obtain multiple second nail placement paths. The first nail placement path and the multiple second nail placement paths constitute a planned nail placement path. The first nail placement path and each of the second nail placement paths have the same nail placement angle, and any of the second nail placement paths does not intersect with any of the bone surface edge points.

[0012] A second aspect of the embodiment of the present application provides a spinal surgery nail placement path planning device, comprising: A spine centerline determination module, used for acquiring a spine image and determining a spine centerline based on the spine image; A screw placement stop point determination module, used to determine the screw placement stop point according to the spinal central axis; A screw insertion point candidate set determination module, used to determine a screw insertion point candidate set based on the screw insertion stop point, wherein the screw insertion point candidate set includes a plurality of candidate screw insertion points located on the transverse processes of the spine; A candidate nail placement path determination module, used to respectively determine a candidate nail placement path formed by any of the candidate nail placement entry points and the nail placement end points; A screw insertion point determination module is used to respectively calculate the distance from each bone surface edge point of the spinal bone surface to each of the candidate screw insertion paths, and determine a screw insertion point from a plurality of the candidate screw insertion points according to the distance; The nail placement path planning module is used to plan the nail placement path based on the nail placement entry point and the nail placement end point.

[0013] A third aspect of an embodiment of the present application provides a computer device, which may be a computer-assisted medical device or a medical robot for implementing spinal surgery nail placement path planning. The computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the computer device implements the method described in the first aspect above.

[0014] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a computer, the method described in the first aspect above is implemented.

[0015] A fifth aspect of the embodiments of the present application provides a computer program product, including a computer program, which, when executed, enables the method described in the first aspect to be executed.

[0016] Compared with the prior art, the embodiments of the present application have the following beneficial effects: In the embodiment of the present application, the computer device can determine the central axis of the spine on the spine image through image processing based on the acquired patient's spine image, and first determine the screw stop point based on the central axis of the spine. Then, the computer device can determine multiple candidate screw entry points on the transverse process of the spine based on the determined screw stop point to form a candidate screw entry point set. The computer device can determine the candidate screw path formed by any candidate screw entry point and the screw stop point, and by respectively calculating the distance from each bone surface edge point of the spinal bone surface to each candidate screw path, determine the best screw entry point from these candidate screw entry points in the candidate screw entry point set, so as to plan a safe screw path based on the screw entry point and the screw stop point. The embodiment of the present application can automatically plan the screw path of spinal surgery by processing the spinal image, improve the accuracy and efficiency of the screw path planning, reduce the labor of the doctor to manually plan the screw path, and avoid the problem of inaccurate screw path planning due to the doctor's subjective factors. Based on the automatically planned screw placement path, the medical robot or surgical robot can safely and accurately perform screw placement operations, ensuring the accuracy of screw placement and helping to improve the success rate of spinal surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a schematic diagram of a spinal surgery nail placement path planning method provided in an embodiment of the present application; Figure 2 It is an algorithm flow chart of a spinal surgery nail placement path planning method provided in an embodiment of the present application; Figure 3 is a schematic diagram of a spinal surgery nail placement path provided in an embodiment of the present application; Figure 4 It is a schematic diagram of an algorithm flow for outputting a final nail placement path in a spinal surgery nail placement path planning method provided in an embodiment of the present application; Figure 5 is a schematic diagram of a spinal surgery nail placement path planning device provided in an embodiment of the present application; Figure 6 It is a schematic diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] In the following description, specific details such as specific system structures, technologies, etc. are proposed for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from hindering the description of the present application.

[0020] The technical solution of the present application is described below through specific embodiments.

[0021] Reference Figure 1 , shows a schematic diagram of a spinal surgery nail placement path planning method provided in an embodiment of the present application, which may specifically include the following steps: S101, acquiring a spinal column image and determining a spinal column central axis based on the spinal column image.

[0022] It should be noted that the method can be applied to a computer device, which can be a computer-assisted medical device or a medical robot that can implement spinal surgery nail placement path planning. That is, the computer device can implement automatic planning of spinal surgery nail placement paths by executing the various steps of the method provided in the embodiment of the present application. The embodiment of the present application does not limit the type of computer device.

[0023] In an embodiment of the present application, a computer device can plan a nail placement path based on the patient's spinal image and other imaging examination results. The above-mentioned spinal image can be a CT image, that is, a CT image of the spinal part or segment where the patient needs to undergo surgery, and the CT image can be a CT image of the cross section of the spine. Specifically, before planning the nail placement path, CT images of the corresponding parts or segments of the patient's spine can be taken, and these CT images can be processed into slice images of the cross section of the spine. When the computer device is planning the nail placement path, it can obtain and process the cross-sectional CT slice images of the patient's surgical part or segment, so as to plan the nail placement path during the operation. Unless otherwise specified, the concepts such as spinal images mentioned in the embodiments of the present application refer to CT slice images of the cross section of the spine.

[0024] When the computer equipment plans the screw placement path based on the spinal CT image, it can first determine the central axis of the patient's spine based on the CT image and locate the position of the spine, thereby ensuring that the end point of the screw placement is accurately determined in the automatic path planning. The end point indicates the end position that the screw can reach when the screw is placed.

[0025] In an embodiment of the present application, after acquiring the spinal image, the computer device can mirror the spinal image to generate a mirror image. For example, the computer device can generate a new mirror image by mirroring the original image left and right. Then, the computer device can identify multiple feature point pairs that match the original spinal image and the newly generated mirror image, thereby determining the spinal axis based on the identified multiple feature point pairs. Exemplarily, the computer device can perform feature matching on the original image and the mirrored image, determine the position of each pair of matching feature points on the original image and the mirror image, and thereby determine the spinal axis on the original image based on each matched feature point pair.

[0026] Specifically, when determining the spine centerline according to a plurality of feature point pairs, the computer device can convert the plurality of feature point pairs into feature description points on the original spine image, and calculate the angle between the straight line formed by each feature description point pair and the image coordinate system X-axis and the midpoint coordinates of each straight line. Exemplarily, each matched feature point pair can be described using information such as subscripts, so as to be processed into a feature description point on the original spine image. The straight line obtained by connecting each pair of feature description points can be used to calculate the angle between the straight line obtained by connecting each pair of feature description points and the image coordinate system X-axis, and the image coordinate system can be the coordinate system corresponding to the original spine image, so the above angle represents the angle between the straight line obtained by connecting each pair of feature description points and the X-axis of its coordinate system on the original spine image. In addition, based on the image coordinate system, the coordinates of the midpoint of the straight line obtained by connecting each pair of feature description points can also be determined. On this basis, the computer device can determine the upper end point and the lower end point of the spine centerline according to the determined angle and the midpoint coordinates, and by connecting the upper end point and the lower end point, the straight line or line segment representing the spine centerline on the original spine image can be obtained.

[0027] In a possible implementation of the embodiment of the present application, after acquiring the spinal image, the computer device may also pre-process the spinal image to remove stains and noise on the image, so that the image details are more prominent, and help the computer device to better analyze the image in the subsequent processing flow. The computer device may pre-process the spinal image by means of binarization and image morphological operations, which are not limited in the embodiment of the present application.

[0028] Therefore, when the embodiment of the present application uses the spinal image to generate a mirror image and determine the spinal central axis, the preprocessed spinal image may be mirrored, and the spinal central axis in the preprocessed spinal image may be determined in combination with the mirror image.

[0029] S102, determining the screw placement stop point according to the central axis of the spine.

[0030] After determining the central axis of the spine on the spine image, the computer device can determine the stop point of screw placement according to the central axis, that is, the screw placement stop point. Generally, the screw placement stop point can be determined to be located on one side of the central axis of the spine based on the actual surgical site.

[0031] In a possible implementation of an embodiment of the present application, in order to determine the screw placement stop point, the computer device may first determine a vertebral reference point on the central axis of the spine, and the vertebral reference point may be determined at different proportions of the central axis according to different surgical sites. Exemplarily, for lumbar surgery, the vertebral reference point may be located at a vertebral position on the central axis that is approximately 80% of the vertebral length. The above proportions may be determined based on the actual screw placement direction. For example, a vertebral position that is approximately 80% of the vertebral length may represent that along the screw placement direction, the position where the screw may be placed may be from the starting point of the screw placement to the bottom of the spinal bone surface, and the length on the central axis of the spine is approximately 80% of the vertebral body.

[0032] Then, the vertebral width can be determined based on the vertebral reference point. The vertebral width represents the distance between two intersection points formed by extending left and right and intersecting with the bone surfaces on both sides based on the vertebral reference point.

[0033] Specifically, after determining the vertebral reference point, a straight line perpendicular to the central axis of the spine can be drawn through the vertebral reference point and made to intersect with the spinal bone surfaces on both sides. The vertebral width can be calculated by calculating the distance between the intersection points on the spinal bone surfaces on both sides.

[0034] The computer device can determine the screw placement stop point by a preset ratio of the vertebral reference point offset to the vertebral width, and the preset ratio can be 1 / 5. For example, after determining the vertebral reference point and calculating the vertebral width as L, the computer device can offset the vertebral reference point by a distance of L / 5 to the side where the screw placement position is located, and use the position point determined after the offset as the screw placement stop point. The line connecting the screw placement stop point and the vertebral reference point is perpendicular to the central axis of the spine.

[0035] S103: Determine a set of candidate screw insertion points based on the screw insertion stop points, wherein the set of candidate screw insertion points includes a plurality of candidate screw insertion points located on the transverse processes of the spine.

[0036] After determining the nail placement end point, the computer device can further determine the nail placement entry point, so as to plan a corresponding designated path according to the nail placement entry point and the nail placement end point.

[0037] In the embodiment of the present application, based on the determined screw insertion stop point, the computer device can first determine a screw insertion point candidate set, and the screw insertion point candidate set can include multiple candidate screw insertion points located on the transverse process of the spine. In this way, the computer device can determine the best screw insertion point from the multiple candidate screw insertion points after processing.

[0038] In the embodiment of the present application, the candidate screw insertion point may be located on the transverse process of the spine. The computer device may determine multiple candidate screw insertion points on the transverse process of the spine according to the inclination angle range of the screw to be inserted, forming a candidate screw insertion point set.

[0039] Different parts or segments of the spine require different inclination angles of screws to be inserted. For example, for the lumbar segment, the inclination angle of the screw during insertion is often between 10-15 degrees. Therefore, by determining the inclination angle range of the screw to be inserted, multiple candidate screw insertion points on the transverse process of the spine can be determined based on the screw insertion stop point and the screw inclination angle range. The above processing procedure is a process of finding a screw insertion angle or path on the transverse process of the spine that meets the screw inclination angle requirement when the screw insertion stop point and the screw inclination angle are determined. Since the screw inclination angle is within a certain angle range, the number of candidate screw insertion points determined on the transverse process of the spine includes multiple.

[0040] S104: Determine a candidate nail placement path formed by any of the candidate nail placement entry points and the nail placement end points.

[0041] In an embodiment of the present application, the candidate nail placement path may be formed by connecting each candidate nail placement entry point to a nail placement end point. Since the number of candidate nail placement entry points includes multiple, the number of candidate nail placement paths formed by the connection also includes multiple. Each candidate nail placement path has a corresponding nail placement direction, which is the direction from the candidate nail placement entry point to the nail placement end point.

[0042] S105, respectively calculating the distance from each bone surface edge point of the spinal bone surface to each of the candidate nail placement paths, and determining a nail placement point from a plurality of the candidate nail placement points according to the distance.

[0043] In the embodiment of the present application, the computer device can determine an optimal nail placement path from the determined multiple candidate nail placement paths, and the candidate nail placement points on the optimal nail placement path are the optimal nail placement points. This process can be determined by calculating the distances between each bone surface edge point on the spinal bone surface and each candidate nail placement path, and by comparing the sizes of multiple distances.

[0044] Specifically, the computer device can extract the spinal bone surface edge by processing the spinal image, that is, determine the various bone surface edge points representing the spinal bone surface on the spinal image. Then, the computer device can determine the minimum distance from the bone surface edge point to each candidate nail placement path for any bone surface edge point. That is, the computer device can traverse each bone surface edge point and calculate the minimum distance from the point to each candidate nail placement path for each bone surface edge point. Therefore, for each bone surface edge point, the computer device can obtain a minimum distance value respectively, and the minimum distance value is the minimum value of the distance from the corresponding bone surface edge point to each candidate nail placement path. In this way, a minimum distance set can be obtained. The computer device can compare the minimum distance values ​​of multiple bone surface edge points again, that is, determine the maximum value from the above-mentioned minimum distance set, and determine the candidate nail insertion point corresponding to the maximum value as the nail insertion point. In this way, the candidate nail insertion point corresponding to the maximum value of the minimum distances of multiple bone surface edge points will be determined as the nail insertion point, and the nail insertion point is also the best nail insertion point corresponding to the best nail placement path.

[0045] S106: planning a nail placement path based on the nail placement entry point and the nail placement end point.

[0046] In the embodiment of the present application, after the nail insertion point and the nail insertion stop point are determined, the corresponding nail insertion direction and angle are determined. The first nail insertion path can be obtained by connecting the nail insertion point and the nail insertion stop point, and the first nail insertion path can be regarded as the optimal planned path. In the surgical operation, the actual nail insertion path is allowed to have a certain offset compared to the optimal first nail insertion path, so the first nail insertion path can be offset in the first direction and the second direction respectively to obtain multiple second nail insertion paths, and the first nail insertion path has the same nail insertion angle as each second nail insertion path. The above-mentioned first direction and second direction can be left and right directions, that is, the computer device can keep the nail insertion angle unchanged, offset the first nail insertion path to the left and right directions, and obtain multiple second nail insertion paths. When offsetting, the computer device can move with a step size of one pixel. At the same time, when the computer device moves the first nail insertion path to obtain the second nail insertion path, it can also calculate whether each second nail insertion path intersects with the bone surface edge point of the spinal bone surface, and obtain all second nail insertion paths that meet the non-intersecting condition. If the second nail placement path intersects with the edge point of the bone surface when moving in a certain direction, the computer device can stop moving in that direction to ensure that any second nail placement path does not intersect with any bone surface edge point. The multiple second nail placement paths obtained through the above movement and the first nail placement path constitute the planned nail placement path, and the area formed by the nail placement path is the safe area for nail placement. In the actual operation, a medical robot or a surgical robot can be used to place nails on the above nail placement path to improve the efficiency and accuracy of nail placement.

[0047] In an embodiment of the present application, the computer device can determine the central axis of the spine on the spine image through image processing based on the acquired patient's spine image, and first determine the screw stop point based on the central axis of the spine. Then, the computer device can determine multiple candidate screw entry points on the transverse process of the spine based on the determined screw stop point to form a candidate screw entry point set. The computer device can determine the candidate screw path formed by any candidate screw entry point and the screw stop point, and by respectively calculating the distance from each bone surface edge point of the spinal bone surface to each candidate screw path, determine the best screw entry point from these candidate screw entry points in the candidate screw entry point set, so as to plan a safe screw path based on the screw entry point and the screw stop point. The embodiment of the present application can automatically plan the screw path of spinal surgery by processing the spinal image, improve the accuracy and efficiency of the screw path planning, reduce the labor of the doctor to manually plan the screw path, and avoid the problem of inaccurate screw path planning due to the doctor's subjective factors. Based on the automatically planned screw placement path, the medical robot or surgical robot can safely and accurately perform screw placement operations, ensuring the accuracy of screw placement and helping to improve the success rate of spinal surgery.

[0048] It should be noted that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0049] For ease of understanding, the spinal surgery nail placement path planning method provided in an embodiment of the present application is introduced below in conjunction with a complete example.

[0050] like Figure 2 FIG. 1 is an algorithm flow chart of a spinal surgery nail placement path planning method provided in an embodiment of the present application. Figure 2 The complete process of nail placement path planning using this algorithm is shown. Figure 2 In the process shown, the computer device may start by acquiring a spinal CT image and extracting the spinal axis and spinal edge by processing the CT image. Figure 2 As shown, based on the extracted spinal axis, the computer device can solve the screw insertion point by calculating the screw insertion depth. Combined with the screw inclination angle range, the computer device can further solve the screw insertion point candidate set B to obtain multiple candidate screw insertion paths S. On the other hand, Figure 2As shown, the bone surface edge point set M can be determined based on the extracted spinal edge. Combining the candidate nail placement path S and the bone surface edge point set M, the computer device can process to obtain the optimal nail placement path and the nail placement safety area. The above-mentioned optimal nail placement path is the first nail placement path in the aforementioned embodiment, and the nail placement safety area is the area where the nail placement path composed of the first nail placement path and multiple second nail placement paths in the aforementioned embodiment is located.

[0051] Specifically, combined Figure 3 Schematic diagram of the spinal surgery nail placement path shown, application Figure 2 The algorithm flow shown in the figure may include the following steps, Step 1 to Step 5, for nail placement path planning: Step 1: First, read the cross-sectional CT image of the spine and perform image preprocessing, including binarization and morphological operations. Then, mirror the image left and right to generate a new mirror image. Perform feature matching between the original image and the mirror image to find the position of each matching feature point, and then find the central axis of the spine.

[0052] Among them, image preprocessing can be achieved by converting the data format and color space of the imported CT image, removing noise using a Gaussian blur algorithm, and obtaining a processed image by performing background segmentation and morphological operations on the image binarization.

[0053] The computer device can mirror the processed image to generate another mirror image (copy image), match the feature points with the original image, obtain the position of the corresponding points, and convert them into feature description points on the original image. By calculating the angle and midpoint coordinates between each pair of matching feature description points and the X-axis of the image coordinate system, after converting to polar coordinates, the upper and lower endpoints of the spinal axis of the CT image can be finally calculated.

[0054] Step 2: Take the vertebral position where 80% of the vertebral length through the central axis of the spine is located, marked as point A. The straight line through point A and perpendicular to the central axis of the spine is the straight line at which the screws on both sides should reach the minimum depth. Find the intersection of this straight line and the edge of the vertebra, and the vertebral width at the straight line is L. The offset distance between the screw insertion stop and point A is L / 5.

[0055] Combination Figure 3 , which is a schematic diagram of a spinal surgery nail placement path provided by an embodiment of the present application. Figure 3The line c shown in part (a) is the determined central axis of the spine. By marking the vertebral position located at about 80% of the vertebral length on the central axis, point A is obtained as the vertebral reference point introduced in the above method embodiment. The vertebral reference point A can be used as a reference to extend to the left and right and intersect with the bone surfaces on both sides to form intersection points P and Q. The distance between the two intersection points P and Q is the vertebral width L. Therefore, the vertebral reference point A is also the intersection of the central axis c of the spine and the straight line PQ. Figure 3 As shown in part (a) of FIG. 1 , the vertebral body reference point A is offset to the left by a distance of L / 5, and the position point E determined after the offset is used as the screw stop point. That is, point E is located on the straight line PQ and the distance between point E and point A is L / 5.

[0056] Step 3: According to the position of the insertion point and the range of the screw inclination angle, the set B of screw entry points on the transverse process of the spine is obtained, that is, the candidate set of screw entry points.

[0057] Specifically, for the lumbar segment, the screw inclination angle is usually 10-15 degrees, and the screw insertion point candidate set B that satisfies the screw insertion can be calculated in combination with the position of the screw stop point. The screw insertion point candidate set B includes multiple candidate screw insertion points located on the transverse process of the spine.

[0058] Step 4: Extract the bone edge points of the CT image and record them as set M. Take a point B0 from set B and calculate the direction of insertion at this time as S with the end point of the screw. Take a point M0 from M, traverse the entire set M, remove the path that intersects with the bone edge and make the minimum distance from M0 to S as large as possible. Figure 3 As shown in part (b) of , it satisfies: dst= .

[0059] The computer device can use the contour search algorithm to obtain the bone surface edge of the spine from the preprocessed CT image, and can remove interfering contours by sorting and filtering the contours, thereby completing the extraction of bone surface edge pixels.

[0060] Then, by determining a candidate screw placement path formed by any candidate screw placement point and the screw placement stop point in the set B, the distance from each bone surface edge point in the spinal bone surface edge set M to each candidate screw placement path can be calculated, so that the screw placement point can be determined from multiple candidate screw placement points based on the distance.

[0061] Step 5: When dst is the maximum, record the inclination angle at this time. The nail placement angle at this time is the optimal nail placement angle, and the path at this time is the optimal nail placement path, that is, the first nail placement path in the above embodiment. By using the current entry point position and nail placement angle, the currently planned first nail placement path is shifted to the left and right by a step of one pixel, and all paths that do not intersect with the set M, that is, the second nail placement path, can be obtained. If there is an intersection, stop moving, and the set formed is the final output nail placement path, that is, the planned safe nail placement path.

[0062] Specifically, see Figure 4 FIG. 1 is a schematic diagram of an algorithm flow for outputting a final nail placement path in a spinal surgery nail placement path planning method provided in an embodiment of the present application. Figure 4 In the algorithm flow shown, in the process of moving the first nailing path, for the input path S[i], the nailing point B[i], and the bone surface edge point M[j], it is necessary to determine whether M[j] intersects with S[i]. If the two intersect, i=i+1 can be set to determine whether i at this time is less than the number iMax of candidate nailing points contained in set B. If i<iMax, it means that the candidate nailing points in set B have not been traversed, and traversal can continue. If the candidate nailing points in set B have been traversed, the corresponding maximum distance maxdst, nailing angle fitangle, and corresponding nailing point point and other information can be output.

[0063] like Figure 4 As shown, if M[j] and S[i] do not intersect, the computer device can solve the minimum distance dst from M[j] to S[i], and determine whether the minimum distance dst solved at this time is greater than the maximum distance maxdst. If dst>maxdst, the maximum distance can be updated so that maxdst=dst, and the current nail placement angle fitangle and the corresponding nail placement point point= B[i] are recorded.

[0064] If the minimum distance dst solved at this time is less than or equal to the maximum distance maxdst, you can continue to traverse the next bone surface edge point, set j=j+1, and determine whether j at this time is less than the number jMax of bone surface edge points contained in the set M. If j<jMax, it means that the bone surface edge points in the set M have not been traversed, and you can continue to traverse.

[0065] according to Figure 4 After the process shown traverses the candidate screw insertion points in set B and the bone surface edge points in set M, the final screw placement path safety area can be obtained.

[0066] Reference Figure 5, shows a schematic diagram of a spinal surgery nail placement path planning device provided by an embodiment of the present application, which may specifically include a spinal central axis determination module 501, a nail placement stop point determination module 502, a nail placement entry point candidate set determination module 503, a candidate nail placement path determination module 504, a nail placement entry point determination module 505 and a nail placement path planning module 506, wherein: A spine centerline determination module 501 is used to obtain a spine image and determine the spine centerline based on the spine image; The screw placement end point determination module 502 is used to determine the screw placement end point according to the spinal axis; A screw insertion point candidate set determination module 503 is used to determine a screw insertion point candidate set based on the screw insertion stop point, wherein the screw insertion point candidate set includes a plurality of candidate screw insertion points located on the transverse processes of the spine; A candidate nail placement path determination module 504 is used to determine a candidate nail placement path formed by any of the candidate nail placement entry points and the nail placement end points; The screw insertion point determination module 505 is used to respectively calculate the distance from each bone surface edge point of the spinal bone surface to each of the candidate screw insertion paths, and determine the screw insertion point from a plurality of the candidate screw insertion points according to the distance; The nail placement path planning module 506 is used to plan the nail placement path based on the nail placement entry point and the nail placement end point.

[0067] In the embodiment of the present application, the spine central axis determination module 501 can be specifically used for: Acquiring a spinal column image and performing mirror processing on the spinal column image to generate a mirror image; Identifying a plurality of feature point pairs that match the spine image and the mirror image; The central axis of the spine is determined according to the plurality of feature point pairs.

[0068] In a possible implementation of the embodiment of the present application, the spine central axis determination module 501 may also be used to: Converting the plurality of feature point pairs into feature description points on the spinal image respectively, and calculating the angle between the straight line formed by each feature description point pair and the X-axis of the image coordinate system and the midpoint coordinates of each straight line; Determine the upper end point and the lower end point of the spine centerline according to the angle and the midpoint coordinates; The spinal column center axis is obtained by connecting the upper end point and the lower end point.

[0069] In the embodiment of the present application, the nail placement stop point determination module 502 can be specifically used for: Determine a vertebral reference point on the central axis of the spine, and determine the vertebral width based on the vertebral reference point; The screw placement stop point is determined by a preset ratio of the vertebral reference point offset from the vertebral width, and a line connecting the screw placement stop point and the vertebral reference point is perpendicular to the central axis of the spine.

[0070] In a possible implementation of the embodiment of the present application, the nail placement stop point determination module 502 may also be used to: A straight line is drawn through the vertebral body reference point and is perpendicular to the central axis of the spine and intersects the spine bone surfaces on both sides; The vertebral width was calculated by calculating the distance between the intersection points on the spinal bone surfaces on both sides.

[0071] In the embodiment of the present application, the pin insertion point candidate set determination module 503 may be specifically used to: Determine the range of inclination angles of the screws to be inserted; According to the screw placement stop point and the screw inclination angle range, multiple candidate screw placement points on the transverse process of the spine are determined.

[0072] In the embodiment of the present application, the nail insertion point determination module 505 can be specifically used to: For any of the bone surface edge points, determining the minimum distance from the bone surface edge point to each of the candidate nail placement paths; The candidate screw insertion point corresponding to the maximum value among the minimum distances of the plurality of bone surface edge points is determined as the screw insertion point.

[0073] In the embodiment of the present application, the nail placement path planning module 506 can be specifically used for: Connecting the screw insertion point and the screw stop point to obtain a first screw insertion path; The first nail placement path is offset along the first direction and the second direction respectively to obtain multiple second nail placement paths. The first nail placement path and the multiple second nail placement paths constitute a planned nail placement path. The first nail placement path and each of the second nail placement paths have the same nail placement angle, and any of the second nail placement paths does not intersect with any of the bone surface edge points.

[0074] The present application also provides a spinal surgery nail placement path planning device, which can be the computer device, medical robot or surgical robot mentioned in the above embodiments. The device can be used to implement the steps in the above method embodiments.

[0075] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiment part.

[0076] Reference Figure 6 , shows a schematic diagram of a computer device provided by an embodiment of the present application. Figure 6As shown, the computer device 600 in the embodiment of the present application includes: a processor 610, a memory 620, and a computer program 621 stored in the memory 620 and executable on the processor 610. When the processor 610 executes the computer program 621, the steps in each embodiment of the above spinal surgery nail placement path planning method are implemented, such as Figure 1 Alternatively, when the processor 610 executes the computer program 621, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 5 Functions of modules 501 to 506 are shown.

[0077] Exemplarily, the computer program 621 can be divided into one or more modules / units, and the one or more modules / units are stored in the memory 620 and executed by the processor 610 to complete the present application. The one or more modules / units can be a series of computer program instruction segments that can complete specific functions, and the instruction segments can be used to describe the execution process of the computer program 621 in the computer device 600. For example, the computer program 621 can be divided into a spinal axis determination module, a screw stop point determination module, a screw entry point candidate set determination module, a candidate screw path determination module, a screw entry point determination module, and a screw path planning module. The specific functions of each module are as follows: A spine centerline determination module, used for acquiring a spine image and determining a spine centerline based on the spine image; A screw placement stop point determination module, used to determine the screw placement stop point according to the spinal central axis; A screw insertion point candidate set determination module, used to determine a screw insertion point candidate set based on the screw insertion stop point, wherein the screw insertion point candidate set includes a plurality of candidate screw insertion points located on the transverse processes of the spine; A candidate nail placement path determination module, used to respectively determine a candidate nail placement path formed by any of the candidate nail placement entry points and the nail placement end points; A screw insertion point determination module is used to respectively calculate the distance from each bone surface edge point of the spinal bone surface to each of the candidate screw insertion paths, and determine a screw insertion point from a plurality of the candidate screw insertion points according to the distance; The nail placement path planning module is used to plan the nail placement path based on the nail placement entry point and the nail placement end point.

[0078] The computer device 600 may be a device capable of implementing each step in the above-mentioned method embodiments, such as a medical robot, a surgical robot, etc. The computer device 600 may include, but is not limited to, a processor 610 and a memory 620. Those skilled in the art will appreciate that Figure 6This is only an example of the computer device 600 and does not constitute a limitation of the computer device 600. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device 600 may also include input and output devices, network access devices, buses, etc.

[0079] The processor 610 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0080] The memory 620 may be an internal storage unit of the computer device 600, such as a hard disk or memory of the computer device 600. The memory 620 may also be an external storage device of the computer device 600, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device 600. Further, the memory 620 may also include both an internal storage unit of the computer device 600 and an external storage device. The memory 620 is used to store the computer program 621 and other programs and data required by the computer device 600. The memory 620 may also be used to temporarily store data that has been output or is to be output.

[0081] An embodiment of the present application further discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the methods described in the above embodiments are implemented.

[0082] The embodiments of the present application further disclose a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a computer, the methods described in the above embodiments are implemented.

[0083] The embodiments of the present application further disclose a computer program product, including a computer program. When the computer program is run on a computer, the computer is enabled to execute the methods described in the aforementioned embodiments.

[0084] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application is described in detail with reference to the above-mentioned embodiments, a person skilled in the art should understand that the technical solutions described in the above-mentioned embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A spinal surgery nail placement path planning method, characterized in that: include: Acquire a spinal column image and determine a spinal column central axis based on the spinal column image; Determine the screw placement stop point according to the spinal axis; Based on the screw placement stop point, determining a set of candidate screw placement points, wherein the set of candidate screw placement points includes a plurality of candidate screw placement points located on the transverse processes of the spine; Respectively determine a candidate nail placement path formed by any of the candidate nail placement entry points and the nail placement end points; Calculating the distance from each edge point of the spinal bone surface to each of the candidate nail placement paths respectively, and determining a nail placement point from a plurality of the candidate nail placement points according to the distance; Based on the screw insertion point and the screw stop point, a screw insertion path is planned.

2. The method according to claim 1, characterized in that The step of acquiring a spinal column image and determining a spinal column central axis based on the spinal column image comprises: Acquiring a spinal column image and performing mirror processing on the spinal column image to generate a mirror image; Identifying a plurality of feature point pairs that match the spine image and the mirror image; The central axis of the spine is determined according to the plurality of feature point pairs.

3. The method according to claim 2, characterized in that Determining the spine centerline according to the plurality of feature point pairs comprises: Converting the plurality of feature point pairs into feature description points on the spinal image respectively, and calculating the angle between the straight line formed by each feature description point pair and the X-axis of the image coordinate system and the midpoint coordinates of each straight line; Determine the upper end point and the lower end point of the spine centerline according to the angle and the midpoint coordinates; The spinal column center axis is obtained by connecting the upper end point and the lower end point.

4. The method according to any one of claims 1 to 3, characterized in that: The method of determining the screw placement stop point according to the spine central axis includes: Determine a vertebral reference point on the central axis of the spine, and determine the vertebral width based on the vertebral reference point; The screw placement stop point is determined by a preset ratio of the vertebral reference point offset from the vertebral width, and a line connecting the screw placement stop point and the vertebral reference point is perpendicular to the central axis of the spine.

5. The method according to claim 4, characterized in that Determining the vertebral width according to the vertebral reference point includes: A straight line is drawn through the vertebral body reference point and is perpendicular to the central axis of the spine and intersects the spine bone surfaces on both sides; The vertebral width was calculated by calculating the distance between the intersection points on the spinal bone surfaces on both sides.

6. The method according to any one of claims 1 to 3 or 5, characterized in that: The step of determining a set of candidate nail insertion points based on the nail insertion stop point includes: Determine the inclination range of the screw to be inserted; According to the screw placement stop point and the screw inclination angle range, multiple candidate screw placement points on the transverse process of the spine are determined.

7. The method according to claim 6, characterized in that The step of determining a nail placement point from a plurality of candidate nail placement points according to the distance comprises: For any of the bone surface edge points, determining the minimum distance from the bone surface edge point to each of the candidate nail placement paths; The candidate screw insertion point corresponding to the maximum value among the minimum distances of the plurality of bone surface edge points is determined as the screw insertion point.

8. The method according to any one of claims 1 to 3 or 5 or 7, characterized in that: The planning of the nail placement path based on the nail placement entry point and the nail placement end point includes: Connecting the screw insertion point and the screw stop point to obtain a first screw insertion path; The first nail placement path is offset along the first direction and the second direction respectively to obtain multiple second nail placement paths. The first nail placement path and the multiple second nail placement paths constitute a planned nail placement path. The first nail placement path and each of the second nail placement paths have the same nail placement angle, and any of the second nail placement paths does not intersect with any of the bone surface edge points.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the computer device is caused to implement the method according to any one of claims 1 to 8.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed, the method according to any one of claims 1 to 8 is executed.

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