Cutting path planning device and method for surgical robot

Abstract

The present invention relates to a surgical robot cutting path planning device and method. The method includes the steps of: determining the position and orientation of an implant to be attached to the bone based on a 3D model of the bone to be operated on; determining the cutting surface of the bone that needs to be cut; determining a cutting start position where the surgical robot will start cutting on the cutting surface and an approach direction of the surgical robot; setting a maximum area within which the cutting path of the surgical robot can be defined based on the cutting start position and approach direction; generating a deformed 3D model that virtually reflects the cut state of the cutting surface; and generating a cutting path of the surgical robot starting from the cutting start position within the maximum area based on the deformed 3D model. This allows for the automatic generation of a cutting path customized for each patient, taking into account the diversity of the patient's bones, thereby further improving surgical outcomes.

Description

[Technical Field]

[0001] The present invention relates to a cutting path planning device and method for a surgical robot, and more particularly to a device and method for planning a cutting path for a bone to be cut by a surgical robot in order to attach an implant during artificial joint replacement surgery using a surgical robot. [Background technology]

[0002] Robotic surgery can be broadly divided into passive, semi-active, and active robotic surgery. Manual robotic surgery is a method in which the surgeon directly operates the robot throughout the entire surgical process, while semi-active robotic surgery involves the surgeon using a robot to perform procedures such as cutting, with the robot using haptic feedback to restrict the surgeon's surgical tool movements to a predetermined path. Active robotic surgery, on the other hand, is a method in which the robot automatically performs surgery according to a planned cutting path without the surgeon's intervention.

[0003] As mentioned above, during active robotic surgery, the robot actively cuts bone, so it is important to plan a cutting path that is suitable for the implant to be installed.

[0004] According to conventional technology, a library of cutting paths defined according to the shape and size of the implant is prepared in advance, and once the planner determines the shape and size of the implant to be attached to the bone of the surgical target, the planner selects and uses the cutting path corresponding to the implant shape and size from the library. However, such library-based cutting paths do not take into account the diversity of bone shapes for each patient, and therefore have limitations in providing customized surgery for each patient.

[0005] In addition, in order to prevent damage to soft tissue, a cutting path is typically generated for an area slightly smaller than the shape of the implant, leaving a predetermined cutting margin. This results in a significant amount of residual bone remaining uncut. The surgeon must then manually cut and finalize the residual bone, which not only causes inconvenience but also slows down the surgical procedure. The cutting margin for minimizing the residual bone varies depending on the specific position of the implant, and conventional library-based cutting paths are difficult to set while taking into account all possible minimum cutting margins for various implant positions, resulting in the problem of a large amount of residual bone remaining. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been devised to solve the problems of the conventional technology as described above, and has an object to provide a cutting path planning device and method for a surgical robot that can generate a cutting path customized for each patient, taking into account the diversity of bones according to the patient, and can minimize the residual bone area. [Means for solving the problem]

[0007] The above-mentioned object can be achieved by a method for planning a cutting path for a surgical robot, according to one aspect of the present invention, comprising the steps of: determining the position and posture of an implant to be attached to the bone of the surgical target based on a 3D model of the bone of the surgical target; determining a cutting surface of the bone of the surgical target that needs to be cut to attach the implant; determining a cutting start position where a surgical robot will start cutting on the cutting surface and an approach direction of the surgical robot at the cutting start position; setting a maximum area in which a cutting path by the surgical robot can be defined based on the cutting start position and the approach direction; generating a deformed 3D model that virtually reflects the cut state of the cutting surface; and generating a cutting path for the surgical robot starting from the cutting start position within the range of the maximum area based on the deformed 3D model.

[0008] At this time, the method may further include a step of setting a safety area for protecting the surrounding tissue of the bone to be operated on, and the cutting path may be generated so that cutting is not performed in the safety area.

[0009] Meanwhile, the cutting start position of the surgical robot is determined as one or more for the cutting surface based on preset skin incision information for cutting the cutting surface and the position of the safety area, and the maximum area and the cutting path can be determined individually corresponding to each cutting start position.

[0010] Furthermore, the cutting path can be generated individually for each cutting surface depending on the number of cutting surfaces to be cut for the installation of the implant.

[0011] The method may further include a step of setting a free cutting area in which the surgical robot can cut freely based on the position of the tissue surrounding the bone of the surgical target and preset skin incision information.

[0012] On the other hand, the step of generating a cutting path for the surgical robot may include the steps of identifying the boundary of the outer contour of the cutting surface in the deformed 3D model, applying a predetermined offset from the boundary of the outer contour to set a cutting margin area that is excluded from cutting, determining a cutting path generation area for generating the cutting path based on the maximum area and the cutting margin area, and generating the cutting path with the cutting path generation area as a boundary.

[0013] The method further includes a step of determining whether cutting of all areas within the cutting path generation area is possible with the surgical robot in a predetermined range of postures, and if cutting of all areas within the cutting path generation area is not possible with the predetermined range of postures, the step of generating the cutting path can generate the cutting path so that after cutting a portion of the area within the cutting path generation area, the surgical robot returns to the cutting start position, and then re-enters after changing the posture of the surgical robot to complete the cutting.

[0014] In addition, the cutting start position of the surgical robot is determined as one or more for the cutting surface based on the preset skin incision information for cutting the cutting surface and the position of the safety area, and the cutting path generation area can be generated in multiple areas corresponding to the multiple cutting start positions, respectively.

[0015] The step of generating a cutting path for the surgical robot may include determining a return position for the surgical robot to return to the cutting start position after cutting.

[0016] In addition, the cutting path may be determined in consideration of the type of cutting tool of the surgical robot and the cutting characteristics of the cutting tool.

[0017] Furthermore, the step of determining the position and orientation of the implant can be determined based on a user input via a user interface unit.

[0018] The above object can also be achieved by a surgical robot cutting path planning device for planning a cutting path of a surgical robot according to another aspect of the present invention, which includes a processor, wherein the processor is configured to: determine, based on a 3D model of the bone of the surgical target, the position and orientation of an implant to be attached to the bone of the surgical target; determine a cutting surface of the bone of the surgical target that needs to be cut to attach the implant; determine, with respect to the cutting surface, a cutting start position where the surgical robot will begin cutting and an approach direction of the surgical robot at the cutting start position; set a maximum area in which a cutting path by the surgical robot can be defined, based on the cutting start position and the approach direction; generate a deformed 3D model that virtually reflects the cut state of the cutting surface; and generate, based on the deformed 3D model, a cutting path of the surgical robot starting from the cutting start position within the range of the maximum area. [Effects of the Invention]

[0019] As described above, according to the present invention, it is possible to further improve surgical effectiveness by automatically generating a cutting path customized for each patient, taking into account the diversity of bones that each patient has.

[0020] Furthermore, the present invention can simplify the surgical process and effectively prevent delays in surgery by generating a cutting path that can minimize the residual bone area remaining after cutting by the surgical robot. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a configuration diagram showing a schematic configuration of a joint replacement robotic surgery system including a cutting path planning device according to an embodiment of the present invention. [Figure 2] 1 is a block diagram showing a detailed configuration of a cutting path planning device according to an embodiment of the present invention. [Figure 3] 1 is a flowchart showing a cutting path planning method for a surgical robot of the cutting path planning device according to an embodiment of the present invention. [Figure 4] FIG. 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention sets a safety area and a free cutting area. [Figure 5] FIG. 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention sets a safety area and a free cutting area. [Figure 6] FIG. 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention sets a maximum area. [Figure 7] FIG. 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention sets a maximum area. [Figure 8] 1 is a flowchart showing a method in which a cutting path planning device according to an embodiment of the present invention generates a cutting path for a surgical robot. [Figure 9] 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention sets the boundary of the outer contour of the cutting surface and the cutting margin area. FIG. [Figure 10] FIG. 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention sets a cutting path generation area. [Figure 11] FIG. 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention sets a cutting path generation area. [Figure 12] FIG. 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention generates a cutting path based on a cutting path generation area. [Figure 13] FIG. 10 is a reference diagram for explaining that the cutting path planning device according to the embodiment of the present invention generates a cutting path based on a cutting path generation area. [Figure 14] 10A and 10B are reference diagrams for explaining the process of coordinate conversion of a cutting path planned via the cutting path planning device according to the embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, in the following description and the accompanying drawings, detailed descriptions of known functions or configurations that may obscure the gist of the present invention will be omitted. It should be noted that the same components are denoted by the same reference numerals throughout the drawings whenever possible.

[0023] The cutting path planning device for a surgical robot according to the present invention plans a cutting path for a bone to be cut by a surgical robot in order to install an implant during artificial joint replacement. The artificial joint replacement procedures described in this specification include total knee replacement, partial knee replacement, and hip replacement. The following description will use total knee replacement as an example of artificial joint replacement.

[0024] FIG. 1 is a diagram showing a schematic configuration of a joint replacement robotic surgery system 1 including a cutting path planning device for a surgical robot according to an embodiment of the present invention.

[0025] Referring to Figure 1, a joint replacement robotic surgery system 1 placed within a surgical site includes bone markers BM1 and BM2 fixed to the bones B1 and B2 of the surgical target, a surgical robot 100, a tracking device 200, and a cutting path planning device 300 (hereinafter referred to as the "cutting path planning device") for the surgical robot.

[0026] The surgical bones B1 and B2 refer to the bones that will be the target of robotic surgery, and the femur B1 and tibia B2 are shown as examples in Figure 1. Bone markers BM1 and BM2 are fixedly attached to the femur B1 and tibia B2, respectively, to serve as references when tracking the positions of the femur B1 and tibia B2 during surgery.

[0027] The surgical robot 100 is a robot for performing surgery for joint replacement and is composed of a robot base 101 and a robot arm 103. Various surgical tools 103a, including a burr, for performing bone cutting and the like can be coupled to the end effector at the end of the robot arm 103. In addition, various sensors can be attached to the surgical robot 100 to sense status information of the surgical robot 100, such as the load applied to the coupled surgical tools and the robot's operating speed. A robot marker RM, which serves as a reference when tracking the position of the surgical robot 100 during surgery, is fixed to the base 101 of the surgical robot 100.

[0028] For reference, the bone markers BM1 and BM2 and the robot marker RM may be passive or active optical markers. The optical marker may include a plurality of branch-like bar members branching in different directions from a center point, with a ball marker formed at the end of each bar. This is only one example of the shape of the optical marker, and it goes without saying that various other known shapes may be used.

[0029] The tracking device 200 tracks the positions and postures of bone markers BM1 and BM2 fixed to bones B1 and B2 of the surgical target and robot marker RM fixed to the surgical robot 100, and may be implemented as an optical tracking system. For reference, the optical tracking system is a device that can track the position and posture in a three-dimensional space in real time by tracking the markers using two infrared cameras and converting the distance using triangulation. The tracking principle of such an optical tracking system is well known, so a detailed description will be omitted for the sake of brevity.

[0030] The cutting path planning device 300 plans a cutting path for the surgical robot 100 on the bones B1 and B2 of the surgical target, which need to be cut to attach an implant to the bones B1 and B2 during joint replacement surgery. The cutting path planning can be performed before the robotic surgery or can be performed according to changes in the plan during the surgery. The cutting path includes information on the positions to which the surgical robot 100 should move when performing cutting and the posture of the surgical robot 100 at those positions. The cutting path can be generated as the relative position and posture of the surgical robot 100 during the cutting process based on the coordinate system of the implant.

[0031] The cutting path planning device 300 may be implemented by including a computer (processor) that plans a cutting path, a display that displays the planned cutting path, and a memory that stores generated cutting path information. For reference, in FIG. 1, the cutting path planning device 300 is illustrated as being implemented as a separate device that is physically separated from the surgical robot 100, but in some cases, the processor and memory of the cutting path planning device 300 may be provided within the surgical robot 100, and the display may be provided together with the tracking device 200 by being connected to it, and various information may be transmitted and received via a communication module.

[0032] 2 is a block diagram showing a detailed configuration of a cutting path planning device 300 according to an embodiment of the present invention. Referring to FIG. 2, the cutting path planning device 300 according to the embodiment of the present invention includes a user interface unit 310, a display unit 320, a memory unit 330, and a processor 340.

[0033] The user interface unit 310 is a module for receiving various inputs from the user in the process of planning the cutting path of the surgical robot 100, and can be realized with various input devices such as a mouse, keyboard, keypad, button, pendant, etc.

[0034] The display unit 320 displays various information including images, graphics, text, etc. on a screen and may be implemented as a liquid crystal display (LCD) panel, a light emitting diode (LED) panel, an organic light emitting diode (OLED) panel, etc. Alternatively, the user interface unit 310 and the display unit 320 may be integrated into a single device, such as a touch screen. The display unit 320 displays various GUIs and planning results provided in the process of planning the position and posture of the implant and the process of planning the cutting path of the surgical robot 100, including an implant model, 2D images and 3D models of the bone to be operated on, and the cutting path of the surgical robot 100.

[0035] The memory unit 330 is implemented with memory devices such as RAM, flash memory, and EPROM, and can store various operating systems (OS), middleware, platforms, and various applications of the cutting path planning device 300, as well as program codes, processed image signals, audio signals, and various data. The memory unit 330 also stores CT images and MRI images of the patient taken before surgery, an implant library storing attribute information of implants such as type, shape, length, and size, information about cutting tools including the type, cutting depth, cutting width, and other cutting tool characteristics of the cutting tools attached to the robot arm of the surgical robot 100, and various reference information used in the process of planning the cutting path of the surgical robot 100.

[0036] The processor 340 executes the program code stored inside the device and executes the cutting path planning procedure for the surgical robot 100 based on the user input entered through the user interface unit 310 and various stored reference information.

[0037] Hereinafter, a method for planning a cutting path for a surgical robot using the cutting path planning device 300 will be described with reference to FIG.

[0038] FIG. 3 is a flowchart showing a cutting path planning method for a surgical robot by the cutting path planning device 300 according to the embodiment of the present invention.

[0039] 3, processor 340 determines the position and orientation of the implant to be attached to the bone of the surgical target based on a 3D model of the bone of the surgical target (S10). Here, the 3D model of the bone of the surgical target is a three-dimensionally reconstructed model of the bone of the surgical target based on medical images of the bone of the surgical target acquired before surgery, such as CT images, MRI images, etc. The 3D model of the bone of the surgical target serves as the basis for planning the cutting path of the surgical robot.

[0040] The position and orientation of the implant can be determined based on a user input via the user interface unit 310. When a user selects an implant to be attached to a bone to be surgically treated from the implant library, the processor 340 generates a virtual model of the selected implant and displays it superimposed on the 3D bone model. An appropriate implant attachment position and orientation, such as an attachment angle, can be determined according to a user input that moves the virtual model of the implant on the 3D bone model via the user interface unit 310.

[0041] Meanwhile, as described above, the determination of the position and orientation of the implant may be performed automatically according to a predetermined implant installation standard, without relying entirely on user input. For example, the processor 340 may be embodied to identify the positions, shapes, sizes, etc. of predetermined landmarks in the 3D bone model, and determine the type of implant and the appropriate position and orientation of the implant according to information on the implant installation standard corresponding to the identified result.

[0042] After the implant planning procedure for determining the position and orientation of the implant is completed, the cutting surface of the surgical target bone is determined according to the planning results (S20). The cutting surface is the surface of the surgical target bone that needs to be cut for implant installation, and the criteria for determining the cutting surface may be preset and saved in accordance with the characteristics of the implant, such as the type, shape, and size of the implant. In this case, one or more cutting surfaces may be determined, and not only flat surfaces but also free-form surfaces customized for each patient may be used. The determination of the cutting surfaces may include determining the position, number, shape, and cutting order of the cutting surfaces.

[0043] Next, the processor 340 sets a safe area and a free cutting area for each cutting surface (S30). For reference, the safe area and the free cutting area may be set based on the coordinate system of the implant, which serves as a reference area when generating a cutting path, as described below. In addition, since the safe area and the free cutting area are associated with the position where the implant is attached, position information of the safe area and the free cutting area may be set in advance as information accompanying information about the shape of the implant. As a result, when an implant to be attached to the bone of the surgical target is selected in the implant planning procedure, the safe area and the free cutting area can be automatically set corresponding to the selected implant.

[0044] The safety zone is an area where soft tissues such as ligaments, blood vessels, muscles, and skin are present around and must not be violated when performing cutting by the surgical robot 100. To protect the tissues around the bone to be operated on, the safety zone is excluded from the cutting path generation area so that cutting is not performed in the safety zone when generating the cutting path.

[0045] When setting a safety area based on the implant coordinate system, the safety area can be set by user input via the user interface unit 310, or by receiving input of position information of soft tissues such as ligaments, blood vessels, and muscles, and skin incision information such as the position and incision length of the skin to be incised during robotic surgery, or can be automatically set by the processor 340 based on pre-stored information.

[0046] On the other hand, the free cutting area is an area where there is no surrounding soft tissue, where the skin is incised during robotic surgery, and there is no need to worry about damaging surrounding tissue during cutting, and where the surgical robot 100 can perform cutting freely. As will be described later, a cutting path is generated so that a predetermined cutting margin area remains to prevent damage to soft tissue such as the skin, but in the free cutting area, it is not necessary to leave a cutting margin area.

[0047] Like the safety area, the free cutting area can be set by user input via the user interface unit 310, or can be automatically set by the processor 340 based on the position information of the surrounding soft tissue and skin incision information.

[0048] Meanwhile, when the cutting path is planned during robotic surgery, the user can directly specify the free cutting area using a probe whose position can be tracked by the tracking device 200. Also, the image of the affected area captured by the camera included in the tracking device 200 or a separate camera can be processed to recognize the skin incision area, and the free cutting area can be set based on the recognized area.

[0049] 4 and 5 are reference diagrams for explaining that the cutting path planning device 300 according to the embodiment of the present invention sets a safety area and a free cutting area. s and free cutting area R f 10A and 10B show a first example and a second example in which the following are set:

[0050] Referring to Figures 4 and 5, the safety region R s and free cutting area Rf can be set for each cutting surface, and one or more can be set on one cutting surface. On the other hand, in the case of areas with the same attribute, they can be set overlapping each other. For example, in Figure 4, two adjacent free cutting areas R f _1, R f You can see that some areas of _2 are overlapping each other.

[0051] In the next step, the processor 340 determines the incision start position where the surgical robot 100 starts cutting the bone of the surgical target for each cutting surface, and the approach direction and posture of the surgical robot at the cutting start position (S40).

[0052] Based on skin incision information when performing cutting, such as the skin incision position and incision length, which is preset or input by the user, as well as the positions of the safety area and free cutting area, the surgical robot 100 can determine one or more cutting start positions for one cutting surface.

[0053] The criteria for determining the cutting start position, approach direction, and posture of the surgical robot 100 may be determined by user input via the user interface unit 310 or may be based on preset criteria corresponding to the cutting surface. That is, the positions, directions, and postures at which the surgical robot 100 can safely approach, as well as the optimal number of such positions, directions, and postures, may be predetermined according to the type of cutting surface, the position, area, shape, and angle of the cutting surface, skin incision information, etc. For example, when the surgical robot 100's range of motion, such as the cutting surface area, cutting surface shape, skin incision information, and the surgical robot 100's posture change angle range, is comprehensively considered, if it is difficult to cut the entire area in one approach, multiple cutting start positions may be determined.

[0054] Meanwhile, when the cutting path is planned during the robotic surgery, a position designated by the user can be set as the cutting start position using a probe whose position can be tracked by the tracking device 200. In addition, an image of the affected area captured by a camera included in the tracking device 200 or a separate camera can be processed to identify a position where there is no risk of soft tissue damage or collision with bones when the surgical robot 100 enters, and the identified position can be determined as the cutting start position.

[0055] Next, the processor 340 sets a maximum area in which a cutting path can be defined by the surgical robot 100 (S50). The maximum area is also generated individually for each cutting surface. The maximum area indicates the maximum limit range in which a cutting path can be generated, and is applied as a criterion for limiting the generation range of the cutting path, so that a cutting path that exceeds the maximum area will not be generated later when the cutting path is generated.

[0056] Such a maximum area can be set individually for each cutting start position based on the cutting start position set in the previous step and the approach direction and posture of the surgical robot, and the maximum area can be determined taking into consideration the characteristics of the bone of the surgical target, such as the size and shape of the bone, and the characteristics of the implant, such as the size and shape of the implant.

[0057] 6 and 7 are reference diagrams for explaining how the cutting path planning device 300 according to an embodiment of the present invention sets a maximum area, and show a first example and a second example in which a maximum area is set, respectively.

[0058] Referring to Figures 6 and 7, the maximum area MP can be defined in the form of a plane extending from the cutting start position Ps, taking into account the approach direction and posture of the surgical robot 100, and the maximum area MP can be determined in various shapes based on the distance between the bone to be operated on and the cutting start position Ps, the approach direction and posture of the surgical robot 100, the characteristics of the bone to be operated on and the implant, etc.

[0059] The maximum area MP is formed to be larger than the size of the implant and the bone to be operated on. In addition, a plurality of maximum areas MP can be set corresponding to each cutting start position Ps, and the plurality of maximum areas MP can have overlapping areas.

[0060] 7, when two cutting start positions Ps_1 and Ps_2 and the approach directions ed_1 and ed_2 and postures corresponding to the cutting start positions Ps_1 and Ps_2 are determined for one cutting surface, a first maximum area MP_1 corresponding to the first cutting start position Ps_1 and a second maximum area MP_2 corresponding to the second cutting start position Ps_2 are generated. In this case, as shown in FIG. 7, the first maximum area MP_1 and the second maximum area MP_2 may have a partially overlapping area.

[0061] For reference, the flowchart in Figure 3 discloses that the maximum area is generated after the safety area and free cutting area are generated, but it goes without saying that this is not limited to the above order, and the steps of generating the safety area and free cutting area can also be performed after the maximum area is generated.

[0062] Next, processor 340 generates a deformed 3D model virtually reflecting the state of the cutting surfaces after cutting (S60). The deformed 3D model is a 3D model that has not actually been cut by surgical robot 100, but is generated by predicting the state of each cutting surface after cutting based on a 3D model of the bone of the surgical target in its pre-cutting state. The deformed 3D model can be generated by predicting the state of each cutting surface after cutting based on the characteristics of the implant attached to the bone of the surgical target, such as the position and posture of the implant, the shape and size of the implant, and the cutting characteristics of the cutting tool that performs the cutting, such as the depth and width of a single cut.

[0063] The deformed 3D models are generated corresponding to the number of cutting surfaces, taking into account the cutting order planned for one or more cutting surfaces. If there is a cutting surface that has already been cut before the cutting of the cutting surface in accordance with the cutting order, a deformed 3D model is created in which the cutting surface is cut in addition to the state in which the other surfaces have already been cut. Therefore, for the first cutting surface to be cut for the first time, an initial deformed 3D model is generated that virtually reflects the cutting state of the first cutting surface based on the initial 3D model of the bone to be operated on. If the deformed 3D model does not correspond to the first cutting surface, a deformed 3D model is sequentially generated that reflects the cutting surface that was cut first according to the cutting order, i.e., that further reflects the cutting state of the corresponding cutting surface based on the deformed 3D model generated immediately before.

[0064] Next, the processor 340 generates a cutting path for the surgical robot 100 starting from the cutting start position within the maximum area based on the deformed 3D model (S70). The cutting path is generated individually for each cutting surface depending on the number of cutting surfaces to be cut for implant installation, and can be defined in various ways, such as a straight line, a curve, or a combination thereof. The cutting path can include not only the movement path of the surgical robot 100 but also information on the posture of the surgical robot 100 along the path.

[0065] Fig. 8 is a flowchart showing a method for generating a cutting path for the surgical robot 100 by the cutting path planning device 300 according to an embodiment of the present invention, and Figs. 9 to 13 are reference diagrams for explaining a process for generating a cutting path for the surgical robot 100 by the cutting path planning device 300 according to an embodiment of the present invention. Hereinafter, the detailed process of step S70 in Fig. 3 will be described with reference to Figs. 8 to 13.

[0066] First, the processor 340 identifies the boundary OL of the outer contour of the cutting surface in the deformed 3D model (S710). In order to generate a cutting path for each cutting surface, the processor 340 can identify the boundary OL of the outer contour of the cutting surface by recognizing the outermost edge of the bone to be operated on on the cutting surface in the deformed 3D model corresponding to the cutting surface.

[0067] Next, the processor 340 sets a cutting margin area ML by applying a predetermined offset from the boundary OL of the outer contour of the cutting surface (S720). Referring to Fig. 9, the cutting margin area ML may be set as an area that is excluded from cutting to protect soft tissue, and is a region that is a predetermined distance inside the bone to be operated on from the boundary OL of the outer contour. The magnitude of the offset into the bone may be a preset value, and may be set to different values ​​depending on the type of cutting tool.

[0068] Next, the processor 340 calculates the boundary OL and cutting margin area ML of the outer contour of the cutting surface, and the safety area R set in the previous step. s and free cutting area R f Based on this, a cutting path generation area CR for generating a cutting path is determined (S730). The cutting path generation area CR essentially means the range in which the cutting path is generated, and the cutting path is generated so that all cutting within the cutting path generation area CR is performed.

[0069] Figures 10 and 11 are reference diagrams for explaining how the cutting path planning device 300 according to an embodiment of the present invention sets a cutting path generation area, and respectively show a first example and a second example of the cutting path generation area CR set by the cutting path planning device 300.

[0070] 10 and 11, the cutting path generation area CR is determined so as to satisfy the following conditions: The cutting path generation area CR includes the cutting start position Ps as a vertex, is defined within the maximum area MP, and is a safety area R s On the other hand, the cutting path generation area CR is generated so as not to exceed the boundary of the cutting margin area ML where the cutting margin area ML does not overlap with the safety area Rs, and the free cutting area R f In this case, the cutting path generation region CR can be generated so as to include the boundary of the bone outer shell without being limited by the cutting margin region ML.

[0071] Meanwhile, as shown in Fig. 11, cutting path generation areas CR_1 and CR_2 can be generated individually corresponding to the cutting start positions Ps_1 and Ps_2. In this case, taking into consideration that the cutting path generation areas CR_1 and CR_2 overlap with each other, the cutting path generation areas CR_1 and CR_2 can be generated or modified by the user so as to minimize the overlapping areas. This is to prevent repeated generation of cutting paths for areas where the cutting path generation areas overlap with each other.

[0072] Once the cutting path generation area CR is generated in this manner, the processor 340 generates a cutting path for the surgical robot 100 using the cutting path generation area CR as a boundary (S740). The cutting path is generated to start from the cutting start position, and may include a return position for the surgical robot 100 to return to the cutting start position after cutting.

[0073] Figures 12 and 13 are reference diagrams for explaining that the cutting path planning device 300 according to an embodiment of the present invention generates a cutting path based on a cutting path generation area, and show a first example and a second example of the cutting path CutP generated by the cutting path planning device 300, respectively.

[0074] 12 and 13, it can be seen that the cutting path CutP is generated so that cutting is performed on all of the interior areas of the cutting path generation area CR. The cutting path CutP starts from the cutting start position Ps and is generated reflecting the approach direction and posture of the surgical robot 100. In addition, the path intervals can be varied in consideration of the type of cutting tool used for cutting and the characteristics of the cutting tool such as the cutting depth and cutting width per cut.

[0075] Meanwhile, the processor 340 may determine whether the surgical robot 100 can cut all areas within the cutting path generation region CR in a predetermined range of postures, taking into account the characteristics of the surgical robot 100 and the characteristics of the cutting tool, such as the posture change range and operating range of the robot arm of the surgical robot 100. If the surgical robot 100 is unable to cut all areas within the cutting path generation region CR in the same posture or with a predetermined range of posture changes, a cutting path CutP may be generated such that the surgical robot 100 cuts some areas within the cutting path generation region CR, returns to the cutting start position Ps, and then re-enters after the posture of the surgical robot 100 to complete the cutting. Figure 12 shows an example in which the cutting path CutP is generated such that the surgical robot 100 first returns from p1 to the cutting start position Ps during cutting, then re-enters from the cutting start position Ps to p2, continues cutting the uncut areas, and finally returns from point p3 to the cutting start position Ps after the cutting is completed.

[0076] Meanwhile, Figure 13 shows an example in which cutting paths CutP_1 and CutP_2 are generated individually corresponding to a plurality of cutting path generation areas CR_1 and CR_2. When cutting paths are generated by dividing the cutting areas for one cutting surface in this manner, the cutting order for each divided cutting area can also be determined. Referring to Figure 13, an example is shown in which a first cutting path CutP_1 is generated, which starts from a first cutting start position Ps_1 and makes a primary return at p11 after cutting is completed for a portion of the first cutting path generation area CR_1, and then the surgical robot 100 moves to a second cutting start position Ps_2, completes cutting for the second cutting path generation area CR_2, and a second cutting path CutP_2 is generated, which makes a final return at p22.

[0077] In this case, as shown in Fig. 13, for part or all of the overlapping area where the first cutting path generation area CR_1 and the second cutting path generation area CR_2 overlap, the surgical robot 100 can generate a cutting path so as not to repeat the process too much. Since cutting is performed in the overlapping area via a cutting path that already corresponds to one cutting path generation area, unnecessary movement of the surgical robot 100 can be prevented by generating a cutting path so that cutting begins in an area where cutting has not yet been performed.

[0078] 12 and 13 show an example in which a cutting path is generated by combining linear paths, but as described above, the shape of the cutting path can be defined in various ways, such as a straight line, a curve, or a combination thereof. For example, if the skin incision area is narrow and it is difficult to cut the entire area that needs to be cut with a linear movement in the left and right direction as shown in FIGS. 12 and 13, an arc-shaped cutting path that rotates left and right around a specific position as a center point can be generated.

[0079] For reference, although an example of planning a cutting path for one cutting surface is shown in FIGS. 4 to 13, cutting paths can be similarly planned for other cutting surfaces in the same manner.

[0080] The cutting path planning for the surgical robot described above can be performed in the pre-surgery planning stage before surgery or in the plan change stage during surgery. For reference, when the cutting path planning is performed in the plan change stage during surgery, the cutting paths for all cutting surfaces can be planned together and then cutting can be performed, or the cutting path generation for each cutting surface and the cutting for that cutting surface can be performed in parallel.

[0081] As described above, the cutting path of the surgical robot 100 is planned based on the coordinate system of the implant, and the surgical robot 100 operates based on the coordinate system of the surgical robot, so a process of aligning these coordinate systems must be performed.

[0082] FIG. 14 is a reference diagram for explaining a coordinate transformation process of a cutting path for utilizing the cutting path planned in the embodiment of the present invention in a robotic surgery.

[0083] As described above, in a robotic surgery system 1 including a robot marker RM attached to a robot, a bone marker BM attached to a bone, and a tracking device 200 that tracks the positions and postures of these markers RM and BM, the transformation matrix for coordinate transformation between the implant coordinate system and the robot coordinate system can be calculated via the following equation:

[0084]

number

[0085] where:

number

number

number

number

number

number

[0086] Since it is well known to calculate a transformation matrix for coordinate transformation between the above-mentioned different coordinate systems during robotic surgery, a detailed description thereof will be omitted for the sake of brevity.

[0087] Based on the transformation matrix between the coordinate systems calculated as described above, the processor 340 can check whether the planned cutting path of the surgical robot 100 is included in the operable area set based on the coordinate system of the surgical robot. The operable area is an area that the surgical robot 100 can approach and where there is no risk of a singularity occurring during operation, and can be preset to various three-dimensional shapes such as a sphere, a rectangular parallelepiped, or a cube, taking into account the position and posture of the surgical robot 100 and the kinematic range of the surgical robot 100.

[0088] If the cutting path defined based on the implant coordinate system is not included in the operable area, the processor 340 can provide a notification via the display unit 320 and provide guidance on the adjustment direction in which the position and posture of the surgical robot 100, the position of the patient, etc. should be adjusted so that the cutting path is included in the operable area.

[0089] As described above, the cutting path planning device 300 and method according to the present invention can further improve surgical outcomes by automatically generating a cutting path customized for each patient, taking into account the bone diversity of each patient. Furthermore, by generating a cutting path that minimizes the residual bone area remaining after cutting by the surgical robot, the surgical process can be simplified and delays in surgery can be effectively prevented.

[0090] Although the above description has been given with all components constituting the embodiments of the present invention combined as a single unit or operating in combination, the present invention is not necessarily limited to such an embodiment. That is, within the scope of the present invention, all components may be selectively combined with one or more other components and operate. Furthermore, all components may be embodied as individual pieces of hardware, or may be embodied as a computer program having program modules that selectively combine some or all of the components to perform some or all of the combined functions in one or more pieces of hardware. Codes and code segments constituting such a computer program would be easily construed by those skilled in the art. Such a computer program may be stored in a computer-readable medium and read and executed by a computer to implement an embodiment of the present invention. Examples of computer program storage media include magnetic recording media, optical recording media, etc.

[0091] In addition, unless otherwise specified, the terms "comprise," "constitute," or "have," as used above, mean that the relevant element can be present, and should be interpreted as including other elements without excluding other elements. All terms, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs, unless otherwise defined. Commonly used terms, such as dictionary-defined terms, should be interpreted to be consistent with the contextual meaning of the relevant art, and should not be interpreted as having an ideal or overly formal meaning unless clearly defined in the present invention.

[0092] The above description merely exemplifies the technical concept of the present invention, and various modifications and variations may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are for illustrative purposes only and do not limit the technical concept of the present invention. The scope of the present invention should be interpreted by the following claims, and all technical concepts within the scope of the claims should be interpreted as being within the scope of the present invention.

Claims

1. A method for planning a cutting path for a surgical robot, in which each step is performed by a cutting path planning device for a surgical robot, determining the position and orientation of an implant to be attached to the bone of the surgical target based on a 3D model of the bone of the surgical target; determining a cutting surface of the bone to be surgically treated that needs to be cut for installation of the implant; determining a cutting start position where a surgical robot starts cutting on the cutting surface and an approach direction of the surgical robot at the cutting start position; setting a maximum area in which a cutting path by the surgical robot can be defined based on the cutting start position and the approach direction; generating a deformed 3D model that virtually reflects the cut state of the cutting surface; A method for planning a cutting path for a surgical robot, comprising: a step of generating a cutting path for the surgical robot starting from the cutting start position within the maximum area based on the deformed 3D model.

2. The method further includes a step of setting a safety zone for protecting surrounding tissues of the bone to be operated on; The method for planning a cutting path for a surgical robot according to claim 1 , wherein the cutting path is generated so that cutting is not performed in the safety area.

3. One or more cutting start positions of the surgical robot are determined for the cutting surface based on preset skin incision information for cutting the cutting surface and the position of the safety area; 3. The method for planning a cutting path for a surgical robot according to claim 2, wherein the maximum area and the cutting path are determined individually corresponding to each cutting start position.

4. 2. The method for planning a cutting path for a surgical robot according to claim 1, wherein the cutting path is generated individually for each cutting surface depending on the number of cutting surfaces to be cut for installing the implant.

5. 2. The method for planning a cutting path for a surgical robot according to claim 1, further comprising a step of setting a free cutting area in which the surgical robot can cut freely based on the position of the surrounding tissue of the bone of the surgical target and preset skin incision information.

6. The step of generating a cutting path for the surgical robot includes: identifying a boundary of the cutting surface contour in the deformed 3D model; applying a predetermined offset from the boundary of the outer contour to set a cutting margin area that is excluded from cutting; determining a cutting path generation area in which the cutting path is generated based on the maximum area and the cutting margin area; The method for planning a cutting path for a surgical robot according to claim 1, further comprising: generating the cutting path using the cutting path generation area as a boundary.

7. The method further includes a step of determining whether cutting of all areas within the cutting path generation area is possible with a predetermined range of postures of the surgical robot; The method for planning a cutting path for a surgical robot, as described in claim 6, characterized in that the step of generating the cutting path generates the cutting path so that, if it is not possible to cut all of the areas within the cutting path generation area with the specified range of posture, the cutting path is cut in a portion of the area within the cutting path generation area, then returns to the cutting start position, and re-enters after changing the posture of the surgical robot to complete the cutting.

8. One or more cutting start positions of the surgical robot are determined for the cutting surface based on preset skin incision information for cutting the cutting surface and the position of the safety area; 7. The method for planning a cutting path for a surgical robot according to claim 6, wherein a plurality of cutting path generation areas are generated corresponding to a plurality of cutting start positions, respectively.

9. 2. The method for planning a cutting path for a surgical robot according to claim 1, wherein the step of generating a cutting path for the surgical robot includes determining a return position for the surgical robot to return to the cutting start position after cutting.

10. 2. The method for planning a cutting path for a surgical robot according to claim 1, wherein the cutting path is determined taking into consideration the type of cutting tool of the surgical robot and the cutting characteristics of the cutting tool.

11. The step of determining the position and orientation of the implant comprises:

2. The method for planning a cutting path for a surgical robot according to claim 1, wherein the path is determined based on a user input via a user interface unit.

12. 1. A surgical robot cutting path planning device for planning a cutting path of a surgical robot, comprising: a processor; The processor: determining the position and orientation of an implant to be attached to the bone of the surgical target based on a 3D model of the bone of the surgical target; determining a cutting surface of the bone of the surgical target that needs to be cut for installation of the implant; determining a cutting start position where the surgical robot starts cutting on the cutting surface and an approach direction of the surgical robot at the cutting start position; Based on the cutting start position and the approach direction, a maximum area in which a cutting path by the surgical robot can be defined is set; generating a deformed 3D model that virtually reflects the cut state of the cutting surface; A surgical robot cutting path planning device configured to generate a cutting path for the surgical robot starting from the cutting start position within the maximum area based on the deformed 3D model.

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