Spinal Surgery Screw Placement Path Planning Method, Device, and Computer Program Product

Abstract

Embodiments of the present application are applicable to the field of computer-aided medical technology, and provide a method, a device, and a computer program product for planning a screw placement path for spinal surgery. The method includes: obtaining a spinal image and determining the central axis of the spine based on the spinal image; determining a screw placement end point according to the central axis of the spine; determining a candidate set of screw placement entry points based on the screw placement end point, where the candidate set of screw placement entry points includes a plurality of candidate screw placement entry points located on the transverse processes of the spine; respectively determining candidate screw placement paths formed by any one of the candidate screw placement entry points and the screw placement end point; respectively calculating the distances from each bone surface edge point of the spinal bone surface to each of the candidate screw placement paths, and determining a screw placement entry point from the plurality of candidate screw placement entry points according to the distances; and planning a screw placement path based on the screw placement entry point and the screw placement end point. By applying the above method, the screw placement path for spinal surgery can be automatically planned, and the accuracy and efficiency of screw placement path planning can be improved.

Description

Technical Field

[0001] The embodiments of the present application belong to the field of computer-aided medical technology, and particularly relate to a method, device, and computer program product for planning the screw insertion path in spinal surgery. Background Art

[0002] In spinal surgery, inserting screws into corresponding segments or positions of the spine is one of the relatively common surgical operations. Currently, when inserting screws in spinal surgery, doctors need to evaluate the anatomical structure and pathological conditions of the spine through imaging examinations such as X-ray, computed tomography (CT), or magnetic resonance imaging (MRI) to determine the optimal position and angle for inserting the screws. Exemplarily, doctors can use CT images to plan the path for inserting the screws, determine the position, angle, and depth of the inserted screws, etc., so as to formulate a detailed surgical plan. However, this method of using CT images to plan the screw insertion path requires doctors to manually adjust the screw insertion path in combination with CT images, which is not only complex and time-consuming, but also easily affected by doctors' subjective factors, resulting in problems such as poor screw insertion. Summary of the Invention

[0003] In view of this, the embodiments of the present application provide a method, device, and computer program product for planning the screw insertion path in spinal surgery to automatically plan the screw insertion path in spinal surgery and improve the accuracy and efficiency of screw insertion path planning.

[0004] The first aspect of the embodiments of the present application provides a method for planning the screw insertion path in spinal surgery, including:

[0005] Obtain a spinal image and determine the spinal central axis based on the spinal image;

[0006] Determine the screw insertion end point according to the spinal central axis;

[0007] Based on the screw insertion end point, determine a set of candidate screw insertion points, where the set of candidate screw insertion points includes multiple candidate screw insertion points located on the transverse process of the spine;

[0008] Respectively determine the candidate screw insertion paths formed by any one of the candidate screw insertion points and the screw insertion end point;

[0009] Respectively calculate the distances 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 the multiple candidate screw insertion points according to the distances;

[0010] Based on the screw insertion point and the screw insertion end point, plan the screw insertion path.

[0011] Optionally, the obtaining of the spinal image and determining the central axis of the spine based on the spinal image includes:

[0012] Obtain a spinal image and perform a mirror image process on the spinal image to generate a mirror image;

[0013] Identify multiple pairs of matching feature points on the spinal image and the mirror image;

[0014] Determine the central axis of the spine according to the multiple pairs of feature points.

[0015] Optionally, the determining of the central axis of the spine according to the multiple pairs of feature points includes:

[0016] Convert the multiple pairs of feature points into feature description points on the spinal image respectively, and calculate the angle between the straight line formed by each pair of feature description points and the X-axis of the image coordinate system and the midpoint coordinates of each straight line;

[0017] Determine the upper endpoint and the lower endpoint of the central axis of the spine according to the angle and the midpoint coordinates;

[0018] Obtain the central axis of the spine by connecting the upper endpoint and the lower endpoint.

[0019] Optionally, the determining of the screw insertion stop point according to the central axis of the spine includes:

[0020] Determine the vertebral body reference point on the central axis of the spine, and determine the vertebral width according to the vertebral body reference point;

[0021] Determine the screw insertion stop point by offsetting a preset ratio of the vertebral width from the vertebral body reference point, and the connection line between the screw insertion stop point and the vertebral body reference point is perpendicular to the central axis of the spine.

[0022] Optionally, the determining of the vertebral width according to the vertebral body reference point includes:

[0023] Draw a straight line perpendicular to the central axis of the spine through the vertebral body reference point and intersect with the spinal bone surfaces on both sides;

[0024] Calculate the distance between the intersection points on the spinal bone surfaces on both sides to obtain the vertebral width.

[0025] Optionally, the determining of the candidate set of screw insertion points based on the screw insertion stop point includes:

[0026] Determine the range of the inner inclination angle of the screw to be inserted;

[0027] Determine multiple candidate screw insertion points on the transverse process of the spine according to the screw insertion stop point and the range of the inner inclination angle of the screw.

[0028] Optionally, determining the nail insertion point from multiple candidate nail insertion points according to the distance includes:

[0029] For any one of the bone surface edge points, determining the minimum distance from the bone surface edge point to each of the candidate nail insertion paths;

[0030] Determining the candidate nail insertion point corresponding to the maximum value among the minimum distances of multiple bone surface edge points as the nail insertion point.

[0031] Optionally, planning the nail insertion path based on the nail insertion point and the nail stop point includes:

[0032] Connecting the nail insertion point and the nail stop point to obtain a first nail insertion path;

[0033] Offsetting the first nail insertion path along a first direction and a second direction respectively to obtain a plurality of second nail insertion paths, the first nail insertion path and the plurality of second nail insertion paths constituting the planned nail insertion path, the nail insertion angles of the first nail insertion path and each of the second nail insertion paths being the same, and any one of the second nail insertion paths not intersecting any of the bone surface edge points.

[0034] A second aspect of the embodiments of the present application provides a spinal surgery nail insertion path planning device, including:

[0035] A spinal column central axis determination module, configured to obtain a spinal column image and determine the central axis of the spinal column based on the spinal column image;

[0036] A nail stop point determination module, configured to determine a nail stop point according to the central axis of the spinal column;

[0037] A nail insertion point candidate set determination module, configured to determine a nail insertion point candidate set based on the nail stop point, the nail insertion point candidate set including a plurality of candidate nail insertion points located on the transverse process of the spinal column;

[0038] A candidate nail insertion path determination module, configured to respectively determine a candidate nail insertion path formed by any one of the candidate nail insertion points and the nail stop point;

[0039] A nail insertion point determination module, configured to respectively calculate the distance from each bone surface edge point of the spinal column bone surface to each of the candidate nail insertion paths, and determine a nail insertion point from multiple candidate nail insertion points according to the distance;

[0040] A nail insertion path planning module, configured to plan a nail insertion path based on the nail insertion point and the nail stop point.

[0041] A third aspect of the embodiments of the present application provides a computer device, which may be a computer-aided medical device or a medical robot for implementing the spinal surgery screw 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.

[0042] A fourth aspect of the embodiments 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.

[0043] A fifth aspect of the embodiments of the present application provides a computer program product, including a computer program. When the computer program runs, the method described in the first aspect above is executed.

[0044] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0045] In the embodiments of the present application, based on the acquired spinal image of the patient, the computer device can determine the spinal central axis on the spinal image through image processing, and first determine the screw placement end point according to the spinal central axis. Then, based on the determined screw placement end point, the computer device can determine a plurality of candidate screw placement entry points on the spinal transverse process to form a candidate set of screw placement entry points. The computer device can determine the candidate screw placement path formed by any candidate screw placement entry point and the screw placement end point, and by calculating the distances from each bone surface edge point of the spinal bone surface to each candidate screw placement path respectively, determine the best screw placement entry point from these candidate screw placement entry points in the candidate set of screw placement entry points, so as to plan a safe screw placement path based on the screw placement entry point and the screw placement end point. Through the processing of the spinal image, the embodiments of the present application can automatically plan the screw placement path for spinal surgery, improve the accuracy and efficiency of screw placement path planning, reduce the labor of doctors in manually planning the screw placement path, and avoid the problem of inaccurate screw placement path planning caused by subjective factors of doctors. Based on the automatically planned screw placement path, a medical robot or a surgical robot can perform the screw insertion operation safely and accurately, ensuring the accuracy of screw placement and helping to improve the success rate of spinal surgery. Description of the Drawings

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 It is a schematic diagram of a method for planning a screw insertion path in spinal surgery provided by an embodiment of the present application;

[0048] Figure 2 It is a flowchart of an algorithm for a method for planning a screw insertion path in spinal surgery provided by an embodiment of the present application;

[0049] Figure 3 It is a schematic diagram of a screw insertion path in spinal surgery provided by an embodiment of the present application;

[0050] Figure 4 It is a schematic flowchart of an algorithm for outputting the final screw insertion path in a method for planning a screw insertion path in spinal surgery provided by an embodiment of the present application;

[0051] Figure 5 It is a schematic diagram of a device for planning a screw insertion path in spinal surgery provided by an embodiment of the present application;

[0052] Figure 6 It is a schematic diagram of a computer device provided by an embodiment of the present application. Detailed implementation manners

[0053] In the following description, specific details such as specific system architectures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand 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 avoid unnecessary details from interfering with the description of the present application.

[0054] The technical solutions of the present application will be described below through specific embodiments.

[0055] Referring to Figure 1 , a schematic diagram of a method for planning a screw insertion path in spinal surgery provided by an embodiment of the present application is shown, which may specifically include the following steps:

[0056] S101. Obtain a spinal image and determine the spinal central axis based on the spinal image.

[0057] It should be noted that this method can be applied to a computer device, which can be a computer-aided medical device or a medical robot capable of realizing the planning of the screw insertion path in spinal surgery. That is, the computer device can automatically plan the screw insertion path in spinal surgery by executing each step of the method provided by the embodiment of the present application. The embodiment of the present application does not limit the type of the computer device.

[0058] In the embodiments of the present application, a computer device may plan a screw insertion path based on imaging examination results such as a patient's spinal image. The above-mentioned spinal image may be a CT image, that is, a CT image of the spinal part or segment where the patient needs to undergo surgery, and this CT image may be a CT image of the spinal cross-section. Specifically, before planning the screw insertion path, CT images of the corresponding part or segment of the patient's spine can be taken, and these CT images can be processed into slice images of the spinal cross-section. When the computer device plans the screw insertion path, it can obtain the cross-sectional CT slice images of the patient's surgical part or segment and process them to plan the screw insertion path during the surgery. Unless otherwise specified, concepts such as spinal images mentioned in the embodiments of the present application all refer to CT slice images of the spinal cross-section.

[0059] When the computer device plans the screw insertion path based on the spinal CT image, it can first determine the central axis of the patient's spine according to the CT image, locate the position of the spine, so as to ensure the accurate determination of the stop point of the screw insertion in the automatic path planning. This stop point represents the end position that the screw can reach when the screw is inserted.

[0060] In the embodiments of the present application, after obtaining the spinal image, the computer device may perform mirror processing on the spinal image to generate a mirror image. For example, the computer device may generate a new mirror image by performing left-right mirror processing on the original image. Then, the computer device may identify multiple pairs of matching feature points on the original spinal image and the newly generated mirror image, and thus determine the spinal central axis according to the identified multiple pairs of feature points. Exemplarily, the computer device may perform feature matching on the original image and the image after mirror processing, determine the positions of each pair of matching feature points on the original image and the mirror image, and thus determine the spinal central axis on the original image according to each pair of matching feature points.

[0061] Specifically, when determining the spinal midline according to multiple pairs of feature points, the computer device can convert multiple pairs of feature points into feature description points on the original spinal image respectively, and calculate the angle between the straight line formed by each pair of feature description points and the X-axis of the image coordinate system, as well as the midpoint coordinates of each straight line. Exemplarily, each matched pair of feature points can be described using information such as subscripts, and thus be processed into feature description points on the original spinal image. The straight line connecting each pair of feature description points can be used to calculate the angle with the X-axis of the image coordinate system, and this image coordinate system can be the coordinate system corresponding to the original spinal image. Therefore, the above-mentioned angle represents the angle between the straight line connecting each pair of feature description points and the X-axis of its coordinate system on the original spinal image. In addition, based on this image coordinate system, the coordinates of the midpoint of the straight line connecting each pair of feature description points can also be determined. On this basis, the computer device can determine the upper endpoint and the lower endpoint of the spinal midline according to the determined angle and midpoint coordinates, and by connecting the upper endpoint and the lower endpoint, a straight line or line segment representing the spinal midline on the original spinal image can be obtained.

[0062] In a possible implementation manner of the embodiment of the present application, after obtaining the spinal image, the computer device can also preprocess the spinal image to remove stains and noises on the image, making the image details more prominent, and helping the computer device to better analyze the image in the subsequent processing flow. The computer device's preprocessing of the spinal image can include means such as binaryzation processing and image morphological operations, and the embodiment of the present application does not limit this.

[0063] Therefore, when generating a mirror image of the spinal image and determining the spinal midline in the embodiment of the present application, it can be to perform mirror processing on the preprocessed spinal image, so as to determine the spinal midline in the preprocessed spinal image in combination with the mirror image.

[0064] S102. Determine the screw insertion stop point according to the spinal midline.

[0065] After determining the spinal midline on the spinal image, the computer device can determine the stop point of screw insertion according to this midline, that is, the screw insertion stop point. Generally, the screw insertion stop point can be determined on a certain side of the spinal midline based on the actual surgical site.

[0066] In a possible implementation of the embodiment of the present application, in order to determine the screw insertion stop point, the computer device can first determine a vertebral body reference point on the spinal axis, and the vertebral body reference point can be determined at different proportional positions on the axis according to different surgical sites. Exemplarily, for lumbar spine surgery, the vertebral body reference point can be located at the vertebral body position about 80% of the vertebral body length on the spinal axis. The above ratio can be determined according to the actual screw insertion direction. For example, the vertebral body position about 80% of the vertebral body length can indicate that along the screw insertion direction, the position where the screw can be inserted can be from the starting point of the screw insertion to the bottom direction of the spinal bone surface, and the length on the spinal axis is about 80% of the vertebral body.

[0067] Then, based on the vertebral body reference point, the vertebral width can be determined, and the vertebral width represents the distance between two intersection points formed by extending left and right from the vertebral body reference point and intersecting with the bone surfaces on both sides.

[0068] Specifically, after determining the vertebral body reference point, a straight line perpendicular to the spinal axis can be drawn through the vertebral body reference point and intersect with the spinal bone surfaces on both sides. By calculating the distance between the intersection points on the spinal bone surfaces on both sides, the vertebral width can be calculated.

[0069] The computer device can determine the screw insertion stop point by offsetting the vertebral width by a preset ratio from the vertebral body reference point, and the above preset ratio can be 1 / 5. Exemplarily, after determining the vertebral body reference point and calculating the vertebral width as L, the computer device can offset the distance of L / 5 from the vertebral body reference point to this side according to which side of the spine the screw insertion position is specifically located, and use the determined position point after offset as the screw insertion stop point. The connection line between the screw insertion stop point and the vertebral body reference point is perpendicular to the spinal axis.

[0070] S103. Based on the screw insertion stop point, determine a set of candidate screw insertion points, and the set of candidate screw insertion points includes multiple candidate screw insertion points located on the spinal transverse process.

[0071] After determining the screw insertion stop point, the computer device can further determine the screw insertion point, so as to plan a corresponding specified path according to the screw insertion point and the screw insertion stop point.

[0072] In the embodiment of the present application, based on the determined screw insertion stop point, the computer device can first determine a set of candidate screw insertion points, and the set of candidate screw insertion points can include multiple candidate screw insertion points located on the spinal transverse process. In this way, the computer device can determine the best screw insertion point from multiple candidate screw insertion points through processing.

[0073] In the embodiment of the present application, the candidate screw insertion points can be located on the spinal transverse process. The computer device can determine multiple candidate screw insertion points on the spinal transverse process according to the range of the inner inclination angle of the screw to be inserted, and form a set of candidate screw insertion points.

[0074] For different spinal regions or segments, the inward inclination angles of the screws to be implanted are different. For example, for the lumbar spine segment, the inward inclination angle during screw implantation often ranges between 10 and 15 degrees. Therefore, by determining the range of the inward inclination angle of the screw to be implanted, and based on the screw insertion stop point and the range of the inward inclination angle of the screw, multiple candidate screw insertion points on the spinal transverse process can be determined. The above processing procedure is a process of finding a screw insertion angle or path on the spinal transverse process that meets the requirements of the inward inclination angle of the screw under the condition of determining the screw insertion stop point and the inward inclination angle of the screw. Since the inward inclination angle of the screw is within a certain angle range, the number of candidate screw insertion points determined on the spinal transverse process includes multiple.

[0075] S104. Respectively determine the candidate screw insertion paths formed by any one of the candidate screw insertion points and the screw insertion stop point.

[0076] In the embodiment of the present application, the candidate screw insertion path can be formed by connecting each candidate screw insertion point to the screw insertion stop point respectively. Since the number of candidate screw insertion points includes multiple, the number of candidate screw insertion paths formed by connection also includes multiple. Each candidate screw insertion path has a corresponding screw insertion direction, and this screw insertion direction is also the direction pointing from the candidate screw insertion point to the screw insertion stop point.

[0077] S105. Respectively calculate the distances from each bone surface edge point on the spinal bone surface to each of the candidate screw insertion paths, and determine the screw insertion point from the multiple candidate screw insertion points according to the distances.

[0078] In the embodiment of the present application, the computer device can determine an optimal screw insertion path from the determined multiple candidate screw insertion paths, and the candidate screw insertion point on this optimal screw insertion path is the optimal screw insertion point. This process can be determined by calculating the distances from each bone surface edge point on the spinal bone surface to each candidate screw insertion path and comparing the magnitudes of the multiple distances.

[0079] Specifically, the computer device can process the spinal image to extract the edge of the spinal bone surface, that is, determine each bone surface edge point representing the spinal bone surface on the spinal image. Then, for any bone surface edge point, the computer device can determine the minimum distance from this bone surface edge point to each candidate screw insertion path. That is, the computer device can traverse each bone surface edge point and calculate the minimum distance from this point to each candidate screw insertion path respectively for each bone surface edge point. Therefore, for each bone surface edge point, the computer device can obtain a minimum distance value respectively, and this minimum distance value is the minimum value among the distances from the corresponding bone surface edge point to each candidate screw insertion path. In this way, a set of minimum distance values 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 set of minimum distance values, and determine the candidate screw insertion point corresponding to this maximum value as the screw insertion point. In this way, the candidate screw insertion point corresponding to the maximum value among the minimum distances of multiple bone surface edge points will be determined as the screw insertion point, and this screw insertion point is also the best screw insertion point corresponding to the best screw insertion path.

[0080] S106. Plan the screw insertion path based on the screw insertion point and the screw stopping point.

[0081] In the embodiment of the present application, after determining the screw insertion point and the screw stopping point, the corresponding screw insertion direction and angle are determined. The first screw insertion path can be obtained by connecting the screw insertion point and the screw stopping point, and this first screw insertion path can be regarded as the best planned path. During the surgical operation, it is allowed that the actual screw insertion path has a certain deviation compared with the best first screw insertion path. Therefore, the first screw insertion path can be offset along the first direction and the second direction respectively to obtain multiple second screw insertion paths, and the screw insertion angles of the first screw insertion path and each second screw insertion path are the same. The above first direction and second direction can be the left - right direction, that is, the computer device can keep the screw insertion angle unchanged and offset the first screw insertion path in the left - right direction to obtain multiple second screw insertion paths. When offsetting, the computer device can move in steps of one pixel. At the same time, when the computer device moves the first screw insertion path to obtain the second screw insertion path, it can also calculate whether each second screw insertion path intersects with the bone surface edge points of the spinal bone surface, and obtain all second screw insertion paths that meet the non - intersection condition. If the second screw insertion path intersects with the bone surface edge point when moving in a certain direction, the computer device can stop the movement in this direction to ensure that any second screw insertion path does not intersect with any bone surface edge point. The multiple second screw insertion paths obtained through the above movement and the first screw insertion path constitute the planned screw insertion path, and the area composed of this screw insertion path is the safe area for screw insertion. During the actual surgical process, a medical robot or a surgical robot can be used to insert screws on the above screw insertion path to improve the screw insertion efficiency and accuracy.

[0082] In the embodiments of the present application, based on the acquired spinal images of a patient, a computer device can determine the central axis of the spine on the spinal images through image processing, and first determine the screw placement stop point according to the central axis of the spine. Then, based on the determined screw placement stop point, the computer device can determine a plurality of candidate screw insertion points on the transverse process of the spine to form a candidate set of screw insertion points. The computer device can determine the candidate screw placement paths formed by any candidate screw insertion point and the screw placement stop point, and by calculating the distances from each bone surface edge point of the spinal bone surface to each candidate screw placement path respectively, determine the optimal screw insertion point from these candidate screw insertion points in the candidate set of screw insertion points, so as to plan a safe screw placement path based on the screw insertion point and the screw placement stop point. Through the processing of spinal images, the embodiments of the present application can automatically plan the screw placement path for spinal surgery, improve the accuracy and efficiency of screw placement path planning, reduce the labor of doctors in manually planning the screw placement path, and avoid the problem of inaccurate screw placement path planning caused by subjective factors of doctors. Based on the automatically planned screw placement path, a medical robot or a surgical robot can perform the screw insertion operation safely and accurately, ensuring the accuracy of screw placement and helping to improve the success rate of spinal surgery.

[0083] It should be noted that the magnitudes of the sequence numbers of the above steps in the embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0084] For the sake of easy understanding, the following introduces the screw placement path planning method for spinal surgery provided by the embodiments of the present application in combination with a complete example.

[0085] As Figure 2 shown, it is the algorithm flowchart of a screw placement path planning method for spinal surgery provided by the embodiments of the present application, Figure 2 showing the complete process of using this algorithm for screw placement path planning. According to the Figure 2 shown process, the computer device can start from acquiring spinal CT images, and through processing the CT images, extract the central axis of the spine and the spinal edge. As Figure 2 shown, based on the extracted central axis of the spine, the computer device can solve the screw placement stop point by calculating the depth of screw insertion. Combining the screw internal inclination angle range, the computer device can further solve the candidate set B of screw insertion points and obtain a plurality of candidate screw placement paths S. On the other hand, as Figure 2As shown, based on the extracted spine edge, the bone surface edge point set M can be determined. By combining the candidate screw placement path S and the bone surface edge point set M, the computer device can process to obtain the optimal screw placement path and the screw placement safety area. The above-mentioned optimal screw placement path is the first screw placement path in the foregoing embodiment, and the screw placement safety area is the area where the screw placement path composed of the first screw placement path and multiple second screw placement paths is located in the foregoing embodiment.

[0086] Specifically, with reference to Figure 3 the schematic diagram of the screw placement path for spinal surgery shown, applying Figure 2 the algorithm flow shown for screw placement path planning may include the following steps Step1 to Step5:

[0087] Step1: First, read the spinal cross-sectional CT image and perform preprocessing of the image, including binarization, morphological operations, etc.; then perform left-right mirror processing on the image to generate a new mirror image, perform feature matching on the original image and the mirror image, find the position corresponding to each matched feature point, and then find the central axis of the spine.

[0088] Among them, for image preprocessing, after converting the data format and color space of the imported CT image, the Gaussian blur algorithm etc. can be used to remove noise, and after background segmentation and morphological operations on the image binarization, the processed image can be obtained.

[0089] The computer device can perform mirroring on the processed image to generate another mirror (duplicate image), perform feature point matching with the original image, obtain the position of the corresponding points, and convert them into feature description points on the original image. By finding the angle and midpoint coordinates of each pair of matched feature description point pairs with the X-axis of the image coordinate system, and after converting to polar coordinate form, the upper and lower endpoints of the central axis of the spine in the CT image can be finally obtained.

[0090] Step2: By taking the vertebral position at 80% of the vertebral body length passing through the central axis of the spine, denoted as point A, the straight line perpendicular to the central axis of the spine passing through point A is the straight line where the depth position that the screws on both sides should at least reach is located. Find the intersection points of this straight line and the vertebral edge, obtain the vertebral width L at the location of the straight line, and the offset distance between the screw insertion stop point and point A is L / 5.

[0091] With reference to Figure 3 the schematic diagram of the screw placement path for spinal surgery provided by the embodiment of the present application shown. In Figure 3The line c shown in part (a) therein is the determined spinal mid-axis line. By marking at the vertebral body position about 80% of the vertebral body length on the mid-axis line to obtain point A as the vertebral body reference point introduced in the foregoing method embodiment, with this vertebral body reference point A as the reference, extend to the left and right respectively 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 body reference point A is also the intersection point of the spinal mid-axis line c and the straight line PQ. As Figure 3 As shown in part (a) therein, offset a distance of L / 5 from the vertebral body reference point A to the left, and use the determined position point E after offset as the screw placement stop point. That is, point E is on the straight line PQ and the distance between point E and point A is L / 5.

[0092] Step3: Obtain the set B of screw entry point positions on the spinal transverse process according to the stop point position and the screw inner inclination angle range, that is, the candidate set of screw entry points.

[0093] Specifically, for the lumbar spine segment, the inner inclination angle of the screw is usually 10-15 degrees. Combining with the position of the screw stop point, the candidate set B of screw entry points that meet the screw placement requirements can be calculated. The candidate set B of screw entry points includes multiple candidate screw entry points located on the spinal transverse process.

[0094] Step4: By extracting the bone surface edge points of the CT image, denoted as set M, take a point B in set B 0 , and find the placement direction S at this time with the screw placement stop point. Take a point M from M 0 , traverse the entire set M, remove the paths that intersect with the bone surface edge and at the same time make the minimum distance from M 0 to S the largest. Combining with Figure 3 as shown in part (b) therein, that is, satisfy:

[0095] dst= .

[0096] Among them, the computer device can use the contour search algorithm for the preprocessed CT image to obtain the bone surface edge of the spine. By steps such as sorting and filtering the contours, the interfering contours can be removed, thus completing the extraction of the bone surface edge pixels.

[0097] Then, by determining the candidate screw placement paths formed by any candidate screw entry point in set B and the screw placement stop point, the distance from each bone surface edge point in the spine bone surface edge set M to each candidate screw placement path can be calculated, so that the screw entry point can be determined from multiple candidate screw entry points according to this distance.

[0098] Step 5: Record the camber angle at this time when dst is the largest. The nail insertion angle at this time is the optimal nail insertion angle, and the path at this time is the optimal nail insertion path, that is, the first nail insertion path in the foregoing embodiment. By the current entry point position and nail insertion angle, the first nail insertion path planned currently is offset in the left and right directions by a step size of one pixel, and all paths that do not intersect with set M can be obtained, that is, the second nail insertion path. If an intersection occurs, stop moving, and the set formed is the finally output nail insertion path, that is, the safe nail insertion path obtained by planning.

[0099] Specifically, referring to Figure 4 shown, it is a schematic algorithm flowchart for outputting the finally nail insertion path in a spinal surgery nail insertion path planning method provided by an embodiment of the present application. According to the Figure 4 shown algorithm flowchart, during the process of moving the first nail insertion path, for the input path S[i], nail insertion entry point B[i], and bone surface edge point M[j], it is necessary to determine whether M[j] intersects with S[i]. If the two intersect, i can be set to i + 1, and it is judged whether the current i is less than the number iMax of candidate nail insertion entry points included in set B. If i < iMax, it means that the candidate nail insertion entry points in set B have not been traversed completely, and traversal can continue. If the candidate nail insertion entry points in set B have been traversed completely, corresponding information such as the maximum distance value maxdst, nail insertion angle fitangle, and corresponding nail insertion entry point point can be output.

[0100] As Figure 4 shown, if M[j] does not intersect with S[i], the computer device can solve the minimum distance dst from M[j] to S[i], and judge whether the solved minimum distance dst at this time is greater than the maximum distance value maxdst. If dst > maxdst, the maximum distance value can be updated so that maxdst = dst, and the nail insertion angle fitangle and the corresponding nail insertion entry point point = B[i] at this time are recorded.

[0101] If the solved minimum distance dst at this time is less than or equal to the maximum distance value maxdst, the next bone surface edge point can be traversed continuously, j is set to j + 1, and it is judged whether the current j is less than the number jMax of bone surface edge points included in set M. If j < jMax, it means that the bone surface edge points in set M have not been traversed completely, and traversal can continue.

[0102] According to the Figure 4 shown process, after traversing the candidate nail insertion entry points in set B and the bone surface edge points in set M, the finally nail insertion path safety region can be obtained.

[0103] Referring to Figure 5, showing 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 mid - axis determination module 501, a nail - placement end - 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, where:

[0104] The spinal mid - axis determination module 501 is used to obtain a spinal image and determine the spinal mid - axis based on the spinal image;

[0105] The nail - placement end - point determination module 502 is used to determine the nail - placement end - point according to the spinal mid - axis;

[0106] The nail - placement entry - point candidate set determination module 503 is used to determine a nail - placement entry - point candidate set based on the nail - placement end - point, and the nail - placement entry - point candidate set includes a plurality of candidate nail - placement entry - points located on the spinal transverse process;

[0107] The candidate nail - placement path determination module 504 is used to determine candidate nail - placement paths formed by any one of the candidate nail - placement entry - points and the nail - placement end - point respectively;

[0108] The nail - placement entry - point determination module 505 is used to calculate the distances from each bone - surface edge point of the spinal bone surface to each of the candidate nail - placement paths respectively, and determine the nail - placement entry - point from the plurality of candidate nail - placement entry - points according to the distances;

[0109] 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.

[0110] In an embodiment of the present application, the spinal mid - axis determination module 501 may specifically be used for:

[0111] Obtain a spinal image and perform a mirror - image processing on the spinal image to generate a mirror - image;

[0112] Identify a plurality of pairs of matching feature points on the spinal image and the mirror - image;

[0113] Determine the spinal mid - axis according to the plurality of pairs of feature points.

[0114] In a possible implementation manner of an embodiment of the present application, the spinal mid - axis determination module 501 may also be used for:

[0115] Convert the plurality of pairs of feature points into feature description points on the spinal image respectively, and calculate the angles between the lines formed by each pair of feature description points and the X - axis of the image coordinate system and the mid - point coordinates of each of the lines;

[0116] Determine the upper - end point and the lower - end point of the spinal mid - axis according to the angles and the mid - point coordinates;

[0117] The spinal axis is obtained by connecting the upper endpoint and the lower endpoint.

[0118] In an embodiment of the present application, the screw placement stop point determination module 502 may specifically be configured to:

[0119] Determine a vertebral body reference point on the spinal axis, and determine the width of the vertebra according to the vertebral body reference point;

[0120] Determine the screw placement stop point by offsetting the vertebral body reference point by a preset ratio of the width of the vertebra, and the line connecting the screw placement stop point and the vertebral body reference point is perpendicular to the spinal axis.

[0121] In a possible implementation manner of the embodiment of the present application, the screw placement stop point determination module 502 may further be configured to:

[0122] Draw a straight line perpendicular to the spinal axis through the vertebral body reference point and intersect with the spinal bone surfaces on both sides;

[0123] Calculate the distance between the intersection points on the spinal bone surfaces on both sides to obtain the width of the vertebra.

[0124] In an embodiment of the present application, the screw placement entry point candidate set determination module 503 may specifically be configured to:

[0125] Determine the range of the included angle of the screw to be implanted;

[0126] According to the screw placement stop point and the range of the included angle of the screw, determine a plurality of candidate screw placement entry points on the transverse process of the spine.

[0127] In an embodiment of the present application, the screw placement entry point determination module 505 may specifically be configured to:

[0128] For any one of the bone surface edge points, determine the minimum distance from the bone surface edge point to each of the candidate screw placement paths;

[0129] Determine the candidate screw placement entry point corresponding to the maximum value among the minimum distances of the plurality of bone surface edge points as the screw placement entry point.

[0130] In an embodiment of the present application, the screw placement path planning module 506 may specifically be configured to:

[0131] Connect the screw placement entry point and the screw placement stop point to obtain a first screw placement path;

[0132] Offset the first screw placement path in the first direction and the second direction respectively to obtain a plurality of second screw placement paths. The first screw placement path and the plurality of second screw placement paths constitute the planned screw placement path. The first screw placement path and each of the second screw placement paths have the same screw placement angle, and any one of the second screw placement paths does not intersect with any one of the bone surface edge points.

[0133] The embodiments of the present application further provide a spinal surgery nail - insertion path planning device, which may be a computer device, a medical robot, a surgical robot, etc. mentioned in the foregoing embodiments. By applying this device, each step in the foregoing method embodiments can be implemented.

[0134] For the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For related parts, refer to the description in the method embodiment section.

[0135] Refer to Figure 6 , which shows a schematic diagram of a computer device provided by an embodiment of the present application. As Figure 6 shown, the computer device 600 in the embodiments 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 - mentioned spinal surgery nail - insertion path planning method are implemented, such as Figure 1 the steps S101 to S106 shown. Or, when the processor 610 executes the computer program 621, the functions of each module / unit in the above - mentioned device embodiments are implemented, such as Figure 5 the functions of the modules 501 to 506 shown.

[0136] Exemplarily, the computer program 621 can be divided into one or more modules / units. 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 capable of performing specific functions, and these 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 mid - axis determination module, a nail - insertion stop - point determination module, a nail - insertion starting - point candidate set determination module, a candidate nail - insertion path determination module, a nail - insertion starting - point determination module, and a nail - insertion path planning module. The specific functions of each module are as follows:

[0137] The spinal mid - axis determination module is used to obtain a spinal image and determine the spinal mid - axis based on the spinal image;

[0138] The nail - insertion stop - point determination module is used to determine the nail - insertion stop - point according to the spinal mid - axis;

[0139] The nail - insertion starting - point candidate set determination module is used to determine a nail - insertion starting - point candidate set based on the nail - insertion stop - point. The nail - insertion starting - point candidate set includes a plurality of candidate nail - insertion starting - points located on the spinal transverse processes;

[0140] A candidate screw insertion path determination module, configured to respectively determine candidate screw insertion paths formed by any one of the candidate screw insertion points and the screw insertion stop points;

[0141] A screw insertion point determination module, configured to respectively calculate the distances 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 multiple candidate screw insertion points according to the distances;

[0142] A screw insertion path planning module, configured to plan a screw insertion path based on the screw insertion point and the screw insertion stop point.

[0143] The computer device 600 may be a device capable of implementing each step in the foregoing various method embodiments, such as a medical robot, a surgical robot, and the like. The computer device 600 may include, but is not limited to, a processor 610 and a memory 620. Those skilled in the art can understand that Figure 6 This is only an example of the computer device 600, and does not constitute a limitation on the computer device 600. It may include more or fewer components than shown in the figure, or combine certain components, or different components. For example, the computer device 600 may further include input / output devices, network access devices, a bus, etc.

[0144] The processor 610 may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or the processor may also be any conventional processor, etc.

[0145] The memory 620 may be an internal storage unit of the computer device 600, such as the 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 the internal storage unit of the computer device 600 and the 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 the data that has been output or is to be output.

[0146] An embodiment of the present application also 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 foregoing various embodiments are implemented.

[0147] An embodiment of the present application also discloses 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 foregoing various embodiments are implemented.

[0148] An embodiment of the present application also discloses a computer program product, including a computer program. When the computer program runs on a computer, the computer is caused to execute the methods described in the foregoing various embodiments.

[0149] 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 has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; 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 various embodiments of the present application, and should all 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 bone surface edge point of the spinal bone surface to each of the candidate nail placement paths; For any of the bone surface edge points, determine the minimum distance from the bone surface edge point to each of the candidate nail placement paths, and determine the candidate nail placement point corresponding to the maximum value of the minimum distances of the plurality of bone surface edge points as the nail placement point, and the nail placement point is the optimal nail placement point corresponding to the optimal nail placement path; Connecting the screw insertion point and the screw insertion stop point to obtain a first screw insertion path, wherein the first screw insertion path is an optimal screw insertion path; Keeping the nail placement angle unchanged, the first nail placement path is offset along the first direction and the second direction with a step size of one pixel 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.

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 point pairs 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. 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 6.

8. 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 6 is executed.

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