Pedicle screw fixation planning system and method

Abstract

To provide a system and method for planning pedicle screw fixation based on an image of a C-arm.SOLUTION: The disclosure relates to a system and method for planning pedicle screw fixation, and more particularly to a system and method for planning the length, insertion path, etc. of a pedicle screw based on an image of a C-arm 10. The system for planning pedicle screw fixation according to the disclosure includes: a C-arm configured to capture a spinal image of a patient; a guider 50 configured to guide a probe to be inserted toward the entry point according to the insertion positions; and a screw determiner 60 configured to determine a length condition of the pedicle screw. According to the disclosure, a C-arm image is used instead of a CT image that has conventionally been used in planning, thereby reducing radiation exposure to a patient and simplifying a surgical procedure.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a system and method for planning fixation of a pedicle screw, and more particularly to a system and method for planning the length, insertion path, etc. of a pedicle screw based on a C-arm image. [Background technology]

[0002] Pedicle screws are used to fixate the spine by being inserted into the vertebral body through the pedicle. Pedicle screw fixation planning is a procedure in which the surgeon determines the appropriate length, diameter, etc. of the pedicle screw depending on the patient and the surgical site, and makes a prior plan for the insertion path of the pedicle screw.

[0003] For the surgeon to carry out planning, an axial view of the spine is most advantageous, as shown in Figure 1. Since the C-arm device cannot provide an axial view of the spine, a computed tomography (CT) is performed before surgery to provide the surgeon with an axial view, enabling him or her to carry out planning before surgery.

[0004] Even though planning is done based on CT images, mobile C-arm X-ray devices are mainly used during actual surgery, so a registration process between the CT images and the C-arm 2D images must be performed in advance to verify in real time whether the surgery is being performed as planned before the surgery and to navigate the surgical tools as planned. Also, if the patient moves or the C-arm device is moved, registration must be performed again.

[0005] As described above, although planning based on CT images has the advantage of being able to utilize axial cross-sectional images, it also has the disadvantage that CT imaging is harmful to the human body due to long-term exposure to radiation, and that it requires coordination with 2D C-arm images.

[0006] On the other hand, C-arm images cannot provide axial cross-sectional images of the spine, and AP (Anterior-Posterior) and LL (Lateral-Lateral) images do not show all the parts of the spine necessary for planning, making them unsuitable for planning.

[0007] Therefore, there is no practice of planning based on C-arm images. However, because the C-arm is an instrument used during surgery, planning based on C-arm images offers many advantages, such as eliminating the need to match 3D CT images with 2D images and providing the flexibility to change the surgical plan as needed even during surgery. Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, the present invention has been devised to solve the above-mentioned conventional problems, and aims to provide a planning system and method capable of planning pedicle screw fixation based on C-arm images. [Means for solving the problem]

[0009] The above object can be achieved by a pedicle screw fixation planning system according to one embodiment of the present invention, comprising: a C-arm for capturing images of the patient's spine; an insertion path providing unit for providing an entry point and an insertion end point of the pedicle screw on the C-arm image; a matching unit for calculating the spatial coordinates of the entry point and the insertion end point based on a reference coordinate system; a guide device for determining an insertion posture of the pedicle screw based on the spatial coordinates of the entry point and the insertion end point and for guiding the insertion of the probe toward the entry point according to the insertion posture; and a screw determination unit for obtaining the coordinates of a start point where the probe comes into contact with the bone as the probe is inserted, and calculating the distance between the coordinates of the insertion end point and the coordinates of the start point to determine the length condition of the pedicle screw.

[0010] Here, the entry point can be determined at any point on a line connecting the insertion endpoint and the center of the pedicle on an AP (Anterior-Posterior) image, and the entry point can be determined at any point on a line extending from the insertion endpoint parallel to the horizontal line of the vertebral body on an LL (Lateral-Lateral) image.

[0011] The system further includes an optical tracking device that tracks the position of the probe to which an optical marker is attached, the alignment unit determines a pixel on the image of the C-arm to which the position of the probe is aligned, and the insertion path providing unit can display a projection image of the probe at the aligned pixel.

[0012] The insertion path providing unit may include a user interface that allows a practitioner to select the entry point and the insertion endpoint on an image of the C-arm.

[0013] The above object can also be achieved by a pedicle screw fixation planning method according to another aspect of the present invention, comprising the steps of: A step of acquiring a C-arm image of a patient's spine via a C-arm; B step of determining an entry point and an insertion end point of a pedicle screw using the C-arm image; C step of calculating spatial coordinates of the entry point and the insertion end point based on a reference coordinate system; D step of determining an insertion posture of the pedicle screw based on the spatial coordinates of the entry point and the insertion end point and guiding the insertion of the probe toward the entry point according to the insertion posture; E step of acquiring, based on the reference coordinate system, a coordinate of a start point where the probe comes into contact with the bone as it is inserted; and F step of calculating a distance between the coordinate of the insertion end point and the coordinate of the start point to determine a length condition of the pedicle screw.

[0014] Here, in step B, the entry point can be determined at any point on a line connecting the insertion endpoint and the center of the pedicle on an AP (Anterior-Posterior) image, or the entry point can be determined at any point on a line extending from the insertion endpoint parallel to the horizontal line of the vertebral body on an LL (Lateral-Lateral) image.

[0015] Then, in step B, the practitioner can select the entry point and the insertion endpoint on the image of the C-arm via a user interface. Effect of the Invention

[0016] The present invention uses C-arm images instead of the existing CT images used for planning, thereby reducing the patient's radiation exposure and simplifying the surgical procedure.

[0017] According to the present invention, the surgical plan based on the C-arm image can be corrected and adjusted during surgery, image alignment can be omitted, and the accuracy of reviewing the progress of surgery and navigation of surgical instruments can be improved. In addition, the screw guide posture used in the planning process can be continuously used in the operation, and the surgical procedure can be performed quickly. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 shows an axial view of the spinal structures. [Diagram 2] FIG. 1 is a schematic block diagram of a pedicle screw fixation planning system according to an embodiment of the present invention. [Diagram 3] 1 is a flowchart of a pedicle screw fixation planning method according to an embodiment of the present invention. [Figure 4a] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 4b] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 5a] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 5b] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 6] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 7a] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 7b] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 8] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 9] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 10a] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. [Figure 10b] FIG. 1 is a schematic diagram for explaining the fixation planning process of a pedicle screw according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0020] FIG. 2 is a schematic block diagram of a pedicle screw fixation planning system according to an embodiment of the present invention.

[0021] Referring to FIG. 2, a pedicle screw fixation planning system according to an embodiment of the present invention includes a C-arm 10, an insertion path providing unit 20, an optical tracking device 30, an alignment unit 40, a guide device 50, and a screw determination unit 60.

[0022] The C-arm 10 is for taking an image of the patient's spine, and takes an X-ray image of the C-arm via an X-ray source and a detector provided at both ends of a C-shaped frame.

[0023] The insertion path providing unit 20 is for providing an entry point and an insertion end point of the pedicle screw corresponding to the C-arm image. Here, the insertion end point means a position of the end of the screw when the pedicle screw is inserted and fixed in the vertebral body, and the entry point means a position selected so that the insertion path of the pedicle screw can be determined based on a relative positional relationship with the insertion end point.

[0024] Information on the entry point and insertion endpoint can be provided by a clinical decision support system (CDSS) that automatically generates recommended position information based on C-arm images. The CDSS can be built based on deep learning of C-arm images, and AI or medical XAI based on various deep learning algorithms such as MLP and CNN can be used.

[0025] Alternatively, the information regarding the entry point and insertion endpoint can be determined by the practitioner specifying the entry point and insertion endpoint on the C-arm image directly via the UI. The practitioner, having the expertise, may be able to select the entry point and insertion endpoint via the UI without the aid of a medical decision support system.

[0026] Alternatively, information regarding entry points and insertion endpoints may be provided in a variety of ways, such as based on standardized statistical criteria for the patient and surgical site, and adjusted directly by the practitioner's expertise.

[0027] The optical tracking device 30 recognizes fiducial markers (not shown) within the surgical space and provides a reference coordinate system for transformation of the positions of various instruments and tools having optical markers thereon to the reference of the reference coordinate system.

[0028] The matching unit 40 is for calculating the spatial coordinates of the entry point and the insertion end point based on the reference coordinate system, that is, for calculating the spatial coordinates of the positions inside the spine corresponding to the entry point and the insertion end point on the C-arm image.

[0029] Specifically, the matching unit 40 can determine the mutual intersection position and calculate the spatial coordinates by back projecting along the X-ray path from the same entry point (or insertion end point) on the AP image and the LL image based on the spatial coordinates of the X-ray source and detector of the C-arm when capturing each of the AP image and the LL image of the C-arm. Here, the spatial coordinates of the X-ray source and detector of the C-arm can be calculated by attaching optical markers to the X-ray source and the detector. However, the surface of the detector and the image of the C-arm must be on the same plane.

[0030] If it is difficult to identify the positions of the X-ray source and detector, alignment can be performed using the method disclosed in Patent Application No. 2019-0028592, "C-arm based medical imaging system and method for aligning 2D images with 3D space," filed by the applicant with the Korean Intellectual Property Office on March 13, 2019. Briefly, the spatial coordinates can be calculated by warping the AP image of the detector surface onto a third plane, back-projecting pixels from the newly generated image into space, and finding the intersection points from multiple images.

[0031] 2 again, the guide device 50 determines the insertion posture of the pedicle screw based on the spatial coordinates of the entry point and the insertion end point, and guides the insertion of the probe toward the entry point. The guide device 50 can be implemented in an automatic or semi-automatic device or a medical robot. In the case of a known medical robot, when only the position coordinates are given, it can automatically move to a position for inserting the screw using the optical tracking device 30 as a medium, and control the posture of the end effector (not shown) and the guide jig so that the probe can be inserted according to the insertion posture.

[0032] The screw determination unit 60 acquires the coordinates of the starting point where the probe touches the bone as the probe is inserted. Here, the insertion depth of the end of the probe can be calculated based on an optical marker attached to the probe or an end effector (not shown) that transmits the insertion force of the probe according to the probe insertion mechanism.

[0033] The screw determination unit 60 calculates the distance between the coordinates of the insertion end point and the coordinates of the starting point to determine the length condition of the pedicle screw. Here, the starting point and the insertion end point represent the total length of the pedicle screw inserted into the spine, and therefore the length condition of the pedicle screw can be determined as the length from the starting point to the insertion end point or a length longer than that by a predetermined length.

[0034] FIG. 3 is a flowchart showing a method for planning fixation of a pedicle screw according to an embodiment of the present invention, and FIGS. 4a to 10b are schematic diagrams for explaining the process of planning fixation of a pedicle screw according to an embodiment of the present invention.

[0035] 3 to 10b, the operation of the pedicle screw fixation planning system according to the embodiment of the present invention shown in FIG. 2 will be described.

[0036] First, an AP image and an LL image of a patient's spine are obtained using the C-arm 10 (S1). Since the capturing of AP and LL images using the C-arm 10 is a technique well known to those skilled in the art, detailed description will be omitted for the sake of simplicity and clarity. Figures 4a and 4b show AP and LL images for explaining a planning process according to an embodiment of the present invention.

[0037] The C-arm 10 provides the captured AP and LL images to the insertion path providing unit 20, and the insertion path providing unit 20 provides an insertion path for the pedicle screw or probe by determining the entry point and insertion end point of the pedicle screw from the AP and LL images (S2).

[0038] 5a and 5b show examples in which an entry point and an insertion end point are displayed on an AP image and an LL image, respectively, according to an embodiment of the present invention.

[0039] 5a, the left ellipse (hereinafter, the first ellipse) ecl1 indicates the insertion end point EP, and the right ellipse (hereinafter, the second ellipse) ecl2 indicates and displays the entry point MP. In other words, the reason for the representation by the ellipse is to represent the point where the pedicle screw is inserted in the oblique direction in the shooting direction of the AP image and the diameter of the pedicle screw, and the first ellipse ecl1 indicates the terminal surface of the pedicle screw, and the center point of the ellipse can be represented by the insertion end point EP and the entry point MP.

[0040] Referring to Figure 5b, the right ellipse (hereinafter, the third ellipse) ecl3 indicates an insertion end point EP, and the left ellipse (hereinafter, the fourth ellipse) ecl4 indicates an entry point MP. The entry point MP and the insertion end point EP shown in Figures 5a and 5b are located in a position where they are linked to each other.

[0041] Referring to FIG. 6, the AP and LL images are taken of the patient's spine in a vertical direction. Therefore, any point P APimg For example, if the entry point is extended in the opposite direction to the X-ray irradiation direction, the source S AP A line leading to an arbitrary point P on the AP image can be obtained, and a line intersecting with the area overlapping with the X-ray irradiation direction when the LL image is taken can be obtained. By projecting this line onto the LL image, the first line L1 can be obtained. APimg , for example, the entry point P on the LL image corresponding to the entry point LLimg is one of the pixels on the first line L1. Therefore, when the position of the entry point on the AP image is changed, the position of the first line L1 is changed, and the position of the entry point on the LL image is modified together.

[0042] The insertion path providing unit 20 displays an AP image and provides an entry point P APimg After the first line L1 corresponding to the selected point is displayed on the LL image, the practitioner selects the entry point P LLimg By selecting "Enter", it is possible to input the entry point MP in the AP image and the LL image. Also, as described above, in addition to the entry point MP, the insertion endpoint EP can be displayed by using a method of recommending and displaying the entry point MP based on a medical decision support system that assists the practitioner.

[0043] In this manner, the pixel coordinate matching between the AP and LL images described via Figures 5a, 5b and 6 can be applied to all pixels on the AP and LL images.

[0044] 7a and 7b are schematic diagrams for explaining a process in which the position of an insertion endpoint is determined on an AP image.

[0045] 7a, a line SL displayed in the longitudinal direction represents the spinous process of the spine, and a circle C displayed to the right of the spinous process SL represents the position of the pedicle. The insertion end point EP on the AP image is selected to be located between the circle C indicating the pedicle and the spinous process SL, and the position of the insertion end point EP and the shape of the ellipse are determined by selecting an ellipse ecl1 centered on the insertion end point EP to be located between the circle C and the spinous process SL.

[0046] 7b, an entry point MP can be selected on a second line L2 connecting the first ellipse ecl1 and the center point of a circle C indicating a pedicle. The two points where the long axis of the first ellipse ecl1, which passes through the insertion end point EP and is perpendicular to the second line L2, meet the first ellipse ecl1 are called EP1 and EP2, respectively, and the two points where the long axis of the second ellipse ecl2, which passes through the entry point MP and is perpendicular to the second line L2, meet the second ellipse ecl2 are called MP1 and MP2, respectively. Then, a line T1 connecting EP1 and MP1 and a line T2 connecting EP2 and MP2 can be obtained.

[0047] Two points (EP1, EP2) obtained from the AP image AP and two points (EP1, EP2) obtained from the LL image in a corresponding manner. LL The two points EP that intersect with each other when projected back along the X-ray path are 1_3d ,EP 2_3d The two points EP 1_3d ,EP 2_3d By determining the distance between the pedicle screws, the diameter of the pedicle screws can be calculated.

[0048] When the insertion end point EP is moved, the shape of the first ellipse ecl1 is changed, and in conjunction with this, the shape of the second ellipse ecl2 is also changed.

[0049] FIG. 8 is a schematic diagram for explaining the process of determining the third ellipse ecl3 corresponding to the insertion end point and the fourth ellipse ecl4 corresponding to the entry point on the LL image.

[0050] The process of selecting an insertion end point and an entry point on the LL image in association with the insertion end point and entry point selected on the AP image has been described above. Similarly, the size of the third ellipse ecl3 and the size of the fourth ellipse ecl4 shown in Fig. 8 can be determined by the pixel matching method of the first ellipse and the second ellipse of the AP image (the method described with reference to Fig. 6). Therefore, when the shape of one of the first to fourth ellipses is changed due to the movement of the center point or the change of the diameter, the shape of the remaining three ellipses is also changed in association with it.

[0051] In the LL image, the lines corresponding to T1 and T2 can be determined in the same way as in the AP image. In the LL image, the second line L2 passing through the insertion end point EP and the entry point MP is positioned parallel to the horizontal line VB displayed on the image of the vertebra body.

[0052] 3 again, in the next step, the matching unit 40 calculates the spatial coordinates of the entry point MP and the insertion end point EP based on the reference coordinate system (S3). Here, the reference coordinate system is set by the optical tracking device 30 recognizing the reference optical markers installed in the medical space.

[0053] As shown in Figure 9, the intersection P of the third line L3 and the fourth line L4, which project the entry point MP (or insertion endpoint) displayed on the mutually perpendicular AP image and LL image in the opposite direction to the X-ray irradiation direction, can be determined in spatial coordinates aligned with the entry point MP.

[0054] However, in order to convert spatial coordinates using the method shown in Fig. 9, position information of the detector plane where the source position and the image are connected when capturing the AP image and the LL image is required. If the position of the detector plane cannot be known, as disclosed in the applicant's aforementioned Patent Application No. 2019-0028592, a warping algorithm is applied to a plane on the X-ray irradiation path where the spatial position can be known to generate an image, and the generated image can be replaced with the AP image or LL image disclosed in Fig. 9.

[0055] The guide device 50 determines the insertion posture of the pedicle screw based on the spatial coordinates of the entry point and the insertion end point, and accordingly guides the insertion of the probe toward the entry point (S4).

[0056] In a medical robot, the spatial coordinates of the entry point and the insertion end point are provided, and the medical robot moves to an appropriate position and positions a probe gripper that guides the insertion direction of the probe according to the insertion posture. The technology of a medical robot moving according to given coordinates and setting the direction of a probe gripper attached to an end effector toward an insertion path connecting the entry point and the insertion end point is a well-known technology in this technical field, so a detailed description is omitted in this specification. Also, even if it is not a medical robot, a well-known bridge-type surgical instrument guide device 50 and the like can be controlled in a similar manner.

[0057] As the probe is inserted, the screw determination unit 60 acquires the coordinates of a point (hereinafter, starting point) SP where the end of the probe starts to contact the bone (S5).

[0058] 10a and 10b are AP and LL images showing the state in which the probe pr has been inserted and is touching the starting point.

[0059] The position SP of the tip of the inserted probe pr varies depending on the insertion depth of the probe, but can be calculated in spatial coordinates using optical markers attached to the probe or the guide device 50. The spatial coordinates of the tip of the probe are aligned with the positions on the AP image and the LL image along the X-ray irradiation direction as shown in Fig. 9, and can be tracked in real time as shown in Figs. 10a and 10b.

[0060] The screw determination unit 60 determines the length of the pedicle screw by calculating the distance between the coordinates of the start point SP and the insertion end point EP based on the coordinates of the two points (S6). The length of the pedicle screw can be selected to be equal to the distance in 3D space between the coordinates of the start point and the insertion end point, or to be longer than this by a predetermined amount.

[0061] As described above, the present invention not only allows the length of the screw to be determined by inserting the probe based on the C-arm image, but also allows the guide set for the probe insertion to be used to insert the pedicle screw, thereby enabling the surgery to be performed quickly and more accurately.

[0062] Although the embodiments of the present invention have been described above, those skilled in the art will understand that the embodiments of the present invention may be modified or substituted without departing from the technical spirit of the present invention. Therefore, the scope of protection of the present invention should be understood to cover the technical spirit described in the claims and its equivalents. [Explanation of symbols]

[0063] 10: C-arm 20: Insertion path providing section 30: Optical tracking device 40: Matching section 50: Guide device 60: Screw decision section

[0064] The inventions described in the original claims of the original application are set forth below. [1] In the pedicle screw fixation planning system, A C-arm that takes images of the patient's spine, An insertion path providing unit that provides an entry point and an insertion end point of the pedicle screw on a C-arm image; A matching unit that calculates spatial coordinates of the entry point and the insertion end point based on a reference coordinate system; A guide device for determining an insertion posture of the pedicle screw based on the spatial coordinates of the entry point and the insertion end point, and guiding the insertion of a probe toward the entry point according to the insertion posture; A pedicle screw fixation planning system, comprising a screw determination unit that acquires the coordinates of the starting point where the probe comes into contact with the bone as the probe is inserted, calculates the distance between the coordinates of the insertion end point and the coordinates of the starting point, and determines the length conditions of the pedicle screw. [2] The fixation planning system for pedicle screws described in [1] is characterized in that the entry point is determined at any point on a line connecting the insertion endpoint and the center of the pedicle on an AP (Anterior-Posterior) image. [3] The fixation planning system for pedicle screws described in [1] is characterized in that the entry point is determined at any point on a line extending from the insertion endpoint parallel to the horizontal line of the vertebral body on the LL (Lateral-Lateral) image. [4] an optical tracking device for tracking the position of the probe having an optical marker attached thereto; The alignment unit determines a pixel on the image of the C-arm to which the position of the probe is aligned; The fixation planning system for pedicle screws described in [1] is characterized in that the insertion path providing unit displays a projection image of the probe in the aligned pixels. [5] The pedicle screw fixation planning system according to any one of claims [1] to [4], characterized in that the insertion path providing unit includes a user interface that allows the surgeon to select the entry point and the insertion endpoint on the C-arm image. [6] In a method for planning fixation of a pedicle screw, A step of acquiring a C-arm image of the patient's spine via a C-arm; Step B: determining an entry point and an insertion end point of the pedicle screw on the C-arm image; A step C of calculating spatial coordinates of the entry point and the insertion end point based on a reference coordinate system; D step of determining an insertion posture of the pedicle screw based on the spatial coordinates of the entry point and the insertion end point, and guiding the insertion of a probe toward the entry point according to the insertion posture; An E step of acquiring coordinates of a starting point where the probe touches a bone as the probe is inserted based on the reference coordinate system; A method for planning fixation of a pedicle screw, comprising: a step F of calculating the distance between the coordinates of the insertion end point and the coordinates of the starting point to determine the length condition of the pedicle screw. [7] The fixation planning method for pedicle screws described in [6], characterized in that in step B, the entry point is determined at any point on a line connecting the insertion endpoint and the center of the pedicle on an AP (Anterior-Posterior) image. [8] The method for pedicle screw fixation planning described in [6], characterized in that in step B, the entry point is determined at any point on a line extending from the insertion endpoint parallel to the horizontal line of the vertebral body on the LL (Lateral-Lateral) image. [9] The method for planning fixation of a pedicle screw described in any one of [6] to [8], characterized in that in step B, the surgeon selects the entry point and the insertion endpoint on the C-arm image via a user interface.

Claims

1. In the pedicle screw fixation planning system, a C-arm for taking images of the patient's spine; An insertion path providing unit that provides an entry point and an insertion end point of a pedicle screw on an AP (Anterior-Posterior) 2D image and an LL (Lateral-Lateral) 2D image acquired through the C-arm; A matching unit that calculates spatial coordinates of the entry point and the insertion end point based on a reference coordinate system; A guide device for determining an insertion posture of the pedicle screw based on the spatial coordinates of the entry point and the insertion end point, and guiding the insertion of a probe toward the entry point according to the insertion posture; an optical tracking device for tracking the position of the probe having an optical marker attached thereto; a screw determination unit that acquires coordinates of a start point where the end of the probe contacts a bone based on the position of the probe tracked by the optical tracking device, calculates a distance between the coordinates of the insertion end point and the coordinates of the start point, and determines a length condition of a pedicle screw; The position of the tip of the probe calculated in spatial coordinates via the optical marker is matched to the position on the 2D image of the AP and the 2D image of the LL and tracked in real time; A pedicle screw fixation planning system, characterized in that the screw determination unit acquires the coordinates of the end of the probe when the end of the probe touches the bone as the coordinates of the starting point.

2. The alignment unit determines pixels on the AP 2D image and the LL 2D image to which the position of the probe is aligned; The fixation planning system for a pedicle screw according to claim 1 , wherein the insertion path providing unit displays a projection image of the probe in the aligned pixels.

3. The fixation planning system for a pedicle screw according to any one of claims 1 to 2, characterized in that the insertion path providing unit includes a user interface that allows a surgeon to select the entry point and the insertion end point on the AP 2D image and the LL 2D image.

Images