Surgical robot cutting path planning apparatus and method thereof

Abstract

The invention relates to equipment for planning a cutting path of a surgical robot and a method thereof. The method for planning the cutting path of the surgical robot comprises the steps that the position and posture of an implant to be installed in a surgical target bone are determined according to a three-dimensional model of the surgical target bone; determining a cutting surface of a surgical target bone needing to be cut for mounting the implant; determining a cutting starting position where the surgical robot starts to cut the cutting surface and an entrance direction of the surgical robot at the cutting starting position; according to the cutting starting position and the entrance direction, setting a maximum area in which a cutting path of the surgical robot can be defined; generating a corrected three-dimensional model, wherein the corrected three-dimensional model reflects the virtual cutting state of the cutting surface; and according to the corrected three-dimensional model, a cutting path of the surgical robot starting from the cutting starting position is created within the range of the maximum area. Accordingly, the cutting path suitable for the patient is automatically created by considering the diversity of the patient's bones, thereby improving the surgical effect.

Description

Technical Field

[0001] The present disclosure relates to a device and method for planning a cutting path of a surgical robot, and more particularly to a device for planning a cutting path of a surgical robot for cutting a surgical target bone so as to install an implant when performing an artificial joint replacement surgery using the surgical robot. Background Art

[0002] Robotic surgery is broadly classified into passive robotic surgery, semi-active robotic surgery, and active robotic surgery. Passive robotic surgery refers to a method where the surgeon personally controls the robot throughout the entire surgical procedure. Semi-active robotic surgery refers to a method where the surgeon uses the robot to perform procedures such as cutting, and during these procedures, the surgeon's movement of the surgical tool is restricted to a predetermined path by the robot based on tactile feedback. Active robotic surgery refers to a method where the robot automatically performs the surgery according to a planned cutting path without the surgeon's intervention.

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

[0004] In the related art, a library that defines cutting paths according to the shape or size of an implant is prepared in advance. When a planner determines the shape and size of an implant to be installed in a surgical target bone, a cutting path corresponding to the determined implant shape and size is selected from the library and used. However, this library-based cutting path does not take into account the diversity of bone shapes of each patient, and therefore has limitations in providing surgery suitable for the patient.

[0005] In addition, the cutting path is usually created for an area slightly smaller than the implant, leaving a predetermined cutting margin to prevent damage to soft tissue, so a considerable portion of the residual bone region remains uncut. This residual bone area is not only inconvenient, but also delays the operation because the surgeon needs to perform additional cutting and final trimming himself. The cutting margin used to minimize the residual bone area varies depending on the specific location of the implant, but traditional library-based cutting paths have difficulty considering all situations of the minimum cutting margin according to the different locations of the implant, so there is still a problem of a large amount of residual bone area. Summary of the invention

[0006] Technical issues

[0007] The present disclosure aims to solve the above problems. One aspect of the present disclosure is to provide an apparatus and method for planning a cutting path of a surgical robot, which can create a cutting path suitable for the patient while considering the diversity of the patient's bones and minimize the residual bone area.

[0008] Technical Solution

[0009] Aspects of the present disclosure can be achieved through a method for planning a cutting path of a surgical robot, the method comprising: determining the position and posture of an implant to be installed in the surgical target bone based on a three-dimensional (3D) model of the surgical target bone; determining the cutting surface of the surgical target bone that needs to be cut to install the implant; determining a cutting start position at which the surgical robot starts cutting the cutting surface, and an entry direction of the surgical robot at the cutting start position; according to the cutting start position and the entry direction, setting a maximum area in which the cutting path of the surgical robot is defined; generating a corrected three-dimensional model reflecting a virtual cutting state of the cutting surface; and according to the corrected three-dimensional model, creating a cutting path for the surgical robot starting from the cutting start position within the range of the maximum area.

[0010] In this case, the method may further include: setting a safety zone to protect tissue surrounding the surgical target bone, wherein the cutting path is created so as not to perform cutting within the safety zone.

[0011] In addition, one or more cutting starting positions of the surgical robot can be determined for the cutting surface based on the preset skin incision information and the position of the safety area for cutting the cutting surface; and the maximum area and cutting path can be determined separately corresponding to each cutting starting position.

[0012] Furthermore, a cutting path can be created separately for each cutting surface, depending on the number of cutting surfaces that need to be cut to install the implant.

[0013] In addition, the method may further include: setting a free cutting area where the surgical robot can freely perform cutting according to the position of tissue around the surgical target bone and preset skin incision information.

[0014] In addition, creating a cutting path for a surgical robot may include: identifying an outer boundary of a cutting surface in a modified three-dimensional model; setting a cutting margin area that is excluded from cutting by applying a predetermined offset from the outer boundary; determining a cutting path creation area for creating a cutting path based on a maximum area and a cutting margin area; and creating a cutting path using the cutting path creation area as a boundary.

[0015] In addition, the method may further include: determining whether the surgical robot can perform cutting on all areas within the cutting path creation area within a predetermined posture range, wherein creating a cutting path includes: once cutting is not performed on all areas within the cutting path creation area within the predetermined posture range, creating a cutting path so that the surgical robot can cut some areas within the cutting path creation area, and then returning to the cutting starting position, and completing the cutting by changing the posture and re-entering the cutting starting position.

[0016] Furthermore, one or more cutting starting positions of the surgical robot can be determined for the cutting surface based on the preset skin incision information and the position of the safety area for cutting the cutting surface; and multiple cutting path creation areas can be determined corresponding to the multiple cutting starting positions.

[0017] In addition, creating a cutting path for the surgical robot may also include: determining a return position for the surgical robot to return to the cutting start position after cutting.

[0018] Furthermore, the cutting path may be determined by considering the type of the cutting tool of the surgical robot and the cutting characteristics of the cutting tool.

[0019] Furthermore, determining the position and posture of the implant may include determining the position and posture of the implant according to a user input performed through a user interface unit.

[0020] Aspects of the present disclosure can be implemented by a surgical robot cutting path planning device, which is used to plan the cutting path of the surgical robot. The device includes a processor, which is configured to: determine the position and posture of an implant to be installed in the surgical target bone based on a three-dimensional model of the surgical target bone; determine the cutting surface of the surgical target bone that needs to be cut to install the implant; determine a cutting start position at which the surgical robot starts cutting the cutting surface, and an entry direction of the surgical robot at the cutting start position; according to the cutting start position and the entry direction, set a maximum area in which the cutting path of the surgical robot is defined; generate a corrected three-dimensional model reflecting the virtual cutting state of the cutting surface; and according to the corrected three-dimensional model, create a cutting path for the surgical robot starting from the cutting start position within the range of the maximum area.

[0021] Beneficial Effects

[0022] As described above, according to the present disclosure, a cutting path suitable for the patient is automatically created by taking into account the diversity of the patient's bones, thereby improving the surgical effect.

[0023] Furthermore, according to the present disclosure, a cutting path is created to minimize the residual bone area remaining after cutting by the surgical robot, thereby simplifying the surgical procedure and effectively preventing surgical delays. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a diagram showing a schematic configuration of a joint replacement robotic surgery system including a cutting path planning apparatus according to an embodiment of the present disclosure.

[0025] Figure 2 is a block diagram showing a detailed configuration of a cutting path planning device according to an embodiment of the present disclosure.

[0026] Figure 3 is a flowchart illustrating a surgical robot cutting path planning method of a cutting path planning device according to an embodiment of the present disclosure.

[0027] Figure 4 and Figure 5 It is a reference view used to illustrate setting of a safety area and a free cutting area by a cutting path planning device according to an embodiment of the present disclosure.

[0028] Figure 6 and Figure 7 It is a reference view used to illustrate setting the maximum area of ​​the cutting path planning device according to an embodiment of the present disclosure.

[0029] Figure 8 is a flowchart showing how a cutting path planning device according to an embodiment of the present disclosure creates a cutting path for a surgical robot.

[0030] Fig. 9 It is a reference view used to illustrate the outer boundary of the cutting surface and the cutting margin area set by the cutting path planning device according to an embodiment of the present disclosure.

[0031] Fig.10 and Fig.11 It is a reference view used to illustrate setting of a cutting path creation area by a cutting path planning device according to an embodiment of the present disclosure.

[0032] Fig.12 and 13 2 is a reference view for explaining that a cutting path planning device according to an embodiment of the present disclosure creates a cutting path based on a cutting path creation area.

[0033] Fig.14 2 is a reference view for explaining a coordinate transformation process of a cutting path planned by a cutting path planning device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] Specific embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, a detailed description of known functions or configurations may obscure the key points of the disclosure in the following description and the accompanying drawings and will therefore be omitted. In addition, it should be noted that throughout the accompanying drawings, the same numbers refer to the same elements and the same elements are represented by the same drawing reference numerals.

[0035] The surgical robot cutting path planning device according to the present disclosure plans the cutting path of the surgical target bone to be cut by the surgical robot when installing an implant in an artificial joint replacement surgery. The artificial joint replacement surgery described in this specification includes total knee replacement surgery, partial knee replacement surgery and hip replacement surgery. The following will take the total knee replacement surgery in the artificial joint replacement surgery as an example for explanation.

[0036] Figure 1 is an illustration of a schematic configuration of a joint replacement robotic surgery system 1 according to an embodiment of the present disclosure, the joint replacement robotic surgery system 1 including a surgical robot cutting path planning device.

[0037] Reference Figure 1 The joint replacement robotic surgical system 1 placed at the surgical site includes bone markers BM1 and BM2 fixed on the surgical target bones B1 and B2, a surgical robot 100, a tracking device 200 and a surgical robot cutting path planning device 300 (hereinafter referred to as "cutting path planning device").

[0038] The surgical target bones B1 and B2 refer to the bones that are the targets of robotic surgery. Figure 1 Taking the femur B1 and tibia B2 as an example, bone markers BM1 and BM2 are fixedly mounted on the femur B1 and tibia B2, respectively, and are used as references for tracking the positions of the femur B1 and tibia B2 during surgery.

[0039] The surgical robot 100 refers to a robot that performs joint replacement surgery. The surgical robot 100 includes a robot base 101 and a robot arm 103. Various surgical tools 103a (including files for cutting bones, etc.) can be attached to the end effector, that is, the end of the robot arm 103. In addition, the surgical robot 100 can be equipped with various sensors that can sense the status information of the surgical robot 100, such as the load applied to the attached surgical tools and the operating speed of the robot. The robot marker RM is fixed to the base 101 of the surgical robot 100 and is used as a reference for tracking the position of the surgical robot 100 during surgery.

[0040] For reference, passive or active optical markers may be used as bone markers BM1 and BM2 and robot marker RM. The optical marker includes a plurality of bar members, the shapes of which are similar to branches forked in different directions relative to a center point, and the ends of each bar member may form a spherical marker. This is only an example of the shape of the optical marker. The optical marker may also be implemented in various other known shapes.

[0041] The tracking device 200 is used to track the position and posture of the bone markers BM1 and BM2 fixed on the surgical target bones B1 and B2 and the robot marker RM fixed on the surgical robot 100, and can be implemented as an optical tracking system (OTS). For reference, the optical tracking system refers to a system that can track the markers through two infrared cameras and convert the distance through triangulation to track the position and posture in three-dimensional space in real time. The tracking principle of this optical tracking system is well known and will not be described in detail for the sake of simplicity.

[0042] The cutting path planning device 300 plans the cutting path of the surgical robot 100 for the surgical target bones B1 and B2 that need to be cut, so as to install implants in the surgical target bones B1 and B2 during joint replacement surgery. The planning of the cutting path can be performed before the robotic surgery, or it can be performed according to the changes in the plan during the operation. The cutting path includes information about the position to which the surgical robot 100 needs to move when performing the cutting, and information about the posture of the surgical robot 100 at the corresponding position. The cutting path can be created as a relative position of the surgical robot 100 based on the implant coordinate system and the posture of the surgical robot 100 during the cutting process.

[0043] The cutting path planning device 300 may be implemented as a computer (processor) that plans a cutting path, a display that displays the planned cutting path, and a memory that stores information about the created cutting path. For reference, Figure 1 The cutting path planning device 300 is shown to be implemented as a separate device physically separated from the surgical robot 100, but in some cases, the processor and memory of the cutting path planning device 300 can be set in the surgical robot 100, and the display and tracking device 200 can be installed and connected together so that they can exchange various information through the communication module.

[0044] Figure 2 is a block diagram showing a detailed configuration of a cutting path planning device 300 according to an embodiment of the present disclosure. Figure 2 According to an embodiment of the present disclosure, the cutting path planning device 300 includes a user interface unit 310 , a display unit 320 , a storage unit 330 and a processor 340 .

[0045] The user interface unit 310 refers to a module for receiving various inputs from a user during the cutting path planning process of the surgical robot 100, and may be implemented by various input devices, such as a mouse, a keyboard, a keypad, buttons, and a pendant.

[0046] The display unit 320 is used to display various information on its screen, including images, graphics, text, etc., and can be implemented as a liquid crystal display (LCD) panel, a light emitting diode (LED) panel, an organic light emitting diode (OLED) panel, etc. In addition, the user input unit 310 and the display unit 320 can be integrated together and implemented as a single device, such as a touch screen. The display unit 320 displays various graphical user interfaces (GUIs) and planning outputs provided in the process of planning the position and posture of the implant and in the process of planning the cutting path of the surgical robot 100, including implant models, two-dimensional images and three-dimensional models of surgical target bones, cutting paths of the surgical robot 100, etc.

[0047] The storage unit 330 is implemented as a storage device, such as a random access memory (RAM), a flash memory, an erasable programmable read-only memory (EPROM), etc., and can be configured to store various operating systems (OS), middleware, platforms and various applications of the cutting path planning device 300, as well as store program codes, processed image signals, audio signals and various data. In addition, the storage unit 330 is configured to store computer tomography (CT) and magnetic resonance imaging (MRI) images of the patient taken before surgery, an implant library containing implant attribute information such as implant type / shape / length / size, information related to the cutting tool installed on the robot arm of the surgical robot 100 (including the type of cutting tool and cutting characteristics such as cutting depth and cutting width), and various reference information used in the cutting path planning process of the surgical robot 100.

[0048] The processor 340 executes program codes stored in the device to perform a cutting path planning procedure of the surgical robot 100 according to user input from the user interface unit 310 and various stored reference information.

[0049] The following will refer to Figure 3 The surgical robot cutting path planning method performed by the cutting path planning device 300 is described.

[0050] Figure 3 is a flowchart illustrating a surgical robot cutting path planning method of the cutting path planning device 300 according to an embodiment of the present disclosure.

[0051] Reference Figure 3, the processor 340 determines the position and posture of the implant to be installed in the surgical target bone according to the three-dimensional model of the surgical target bone (S10). The three-dimensional model of the surgical target bone refers to a model in which the surgical target bone is three-dimensionally reconstructed according to a medical image (such as a CT image or an MRI image) of the surgical target bone taken before the operation. The three-dimensional model of the surgical target bone is the basis for planning the cutting path of the surgical robot.

[0052] The position and posture of the implant can be determined according to the user input performed through the user interface unit 310. When the user selects an implant to be installed in the surgical target bone from the implant library, the processor 340 creates a virtual model of the selected implant and superimposes and displays the virtual model on the three-dimensional bone model so that the appropriate installation position and posture of the implant, such as the installation angle, can be determined according to the user input, wherein the user input is used to move the virtual model of the implant on the three-dimensional bone model through the user interface unit 310.

[0053] In addition, as described above, the position and posture of the implant can be automatically determined according to the preset implant installation standard without having to rely entirely on user input. For example, the processor 340 can identify the position of a predetermined landmark in the three-dimensional bone model and the shape, size, etc. of the corresponding landmark, and can determine the type of implant and the appropriate position and posture of the implant according to the implant installation standard information corresponding to the recognition result.

[0054] When the implant planning program for determining the installation position and posture of the implant is completed, the cutting surface of the surgical target bone is determined according to the above planning results (S20). The cutting surface refers to the surface of the surgical target bone that needs to be cut when the implant is installed, and the standards for determining the cutting surface can be preset and stored corresponding to the implant characteristics such as the type, shape and size of the implant. In this case, a single or multiple cutting surfaces can be determined. The cutting surface can be cut not only into a plane, but also into a curved shape to meet the needs of the patient. The determination of the cutting surface may include determining the position of the cutting surface, the number of cutting surfaces, the shape of the cutting surface, and the cutting order of the cutting surface.

[0055] Next, the processor 340 sets a safety area and a free cutting area for each cutting surface (S30). For reference, the safety area and the free cutting area refer to areas used as a reference when creating a cutting path, and can be set according to an implant coordinate system (described later). In addition, the safety area and the free cutting area are related to the position where the implant is to be installed, so the position information of the safety area and the free cutting area can be set in advance and used as additional information of the implant shape information. Therefore, when an implant to be installed in the surgical target bone is selected in the implant planning program, the safety area and the free cutting area can be automatically set corresponding to the selected implant.

[0056] The safety area refers to an area around which soft tissues such as ligaments, blood vessels, muscles and skin exist and should not be invaded when the surgical robot 100 performs cutting. In order to protect the tissues around the surgical target bone, when creating the cutting path, the safety area is excluded from the cutting path creation area so that cutting cannot be performed in the safety area.

[0057] When setting the safety area according to the implant coordinate system, the safety area can be set according to the user input through the user interface unit 310, or it can be automatically set by the processor 340 according to the following information or according to pre-stored information: information input about the position of soft tissues such as ligaments, blood vessels and muscles, and skin incision information such as the position and length of the skin to be incised in robotic surgery.

[0058] The free cutting area refers to an area that allows the surgical robot 100 to cut freely without worrying about damage to surrounding tissues. After the skin is cut, there is no soft tissue around the free cutting area, so during robotic surgery, there is no need to worry about damaging surrounding tissues when cutting bones in the free cutting area. As described below, in order to prevent damage to soft tissues such as skin, a predetermined cutting margin area is reserved when creating a cutting path, but a cutting margin area does not need to be reserved in the free cutting area.

[0059] Similar to the safety area, the free cutting area may be set according to user input via the user interface unit 310, or may be automatically set by the processor 340 according to the position information of the soft tissue and the skin incision information.

[0060] When planning a cutting path during robotic surgery, the user can personally specify a free cutting area using a probe, wherein the tracking device 200 can track the position of the probe. In addition, an image of the affected area taken by a separate camera or a camera included in the tracking device 200 can be processed to identify a skin incision area, and the free cutting area can be set according to the identified skin incision area.

[0061] Figure 4 and Figure 5 are reference views for explaining how the cutting path planning device 300 sets a safety area and a free cutting area according to an embodiment of the present disclosure. These reference views are views showing how the safety area R is set for a cutting surface. s and free cutting area R f The first example and the second example.

[0062] Reference Figure 4 and Figure 5 , you can set a safe area R for each cutting surface sand free cutting area R f , and can set single or multiple regions on a cutting surface. At the same time, regions with the same attributes can be set to overlap each other. For example, Figure 4 Showing two adjacent free cut areas R f _1 and R f _2 are set to partially overlap each other.

[0063] Next, the processor 340 determines a cutting start position at which the surgical robot 100 starts cutting the surgical target bone for each cutting plane, and an entry direction and posture of the surgical robot at the cutting start position ( S40 ).

[0064] Based on the skin incision information during the cutting process (such as the skin incision position and the incision length) and based on the positions of the safety area and the free cutting area, one or more cutting starting positions of the surgical robot 100 relative to one or more cutting surfaces can be determined, wherein the skin incision information can be preset or can be input by the user.

[0065] The criteria for determining the cutting starting position and entry direction / posture of the surgical robot 100 may be determined based on user input through the user interface unit 310, or may be determined based on preset criteria corresponding to the cutting surface. In other words, the position and direction / posture that the surgical robot 100 can safely enter and its optimal number may be preset corresponding to the type of cutting surface, the position, area, shape and angle of the cutting surface, skin incision information, etc. For example, taking into account the area of ​​the cutting surface, the shape of the cutting surface, the skin incision information, and the range of motion of the surgical robot 100 (such as the range of angles of posture change of the surgical robot 100), if it is difficult to enter once and cut all areas, multiple cutting starting positions may be set.

[0066] When planning a cutting path during robotic surgery, a user-specified position may be used as a cutting start position by using a probe, wherein the position of the probe may be tracked by the tracking device 200. In addition, images of the affected area captured by a separate camera or a camera included in the tracking device 200 may be processed to identify a position where the surgical robot 100 can enter without causing damage to soft tissue or collision with bones, etc., and the identified position may be set as the cutting start position.

[0067] Next, the processor 340 sets a maximum area within which the cutting path of the surgical robot 100 can be defined (S50). The maximum area is also generated separately for each cutting surface. The maximum area refers to the maximum limit range in which a cutting path can be created, and is used as a standard for limiting the creation range of the cutting path so that a cutting path exceeding the maximum area cannot be created when a cutting path is created in the future.

[0068] The maximum area can be set separately for each cutting start position according to the entry direction / posture of the surgical robot and the cutting start position set in the previous step. The maximum area can be determined by considering the characteristics of the surgical target bone (such as the size and shape of the surgical target bone) and the characteristics of the implant (such as the size and shape of the implant).

[0069] Figure 6 and Figure 7 1 and 2 are reference views for explaining setting of a maximum area by the cutting path planning apparatus 300 according to an embodiment of the present disclosure, and these reference views respectively show a first example and a second example of setting the maximum area.

[0070] Reference Figure 6 and Figure 7 , the maximum area MP may be defined in the form of a plane extending from the cutting start position Ps, taking into account the entry direction / posture of the surgical robot 100. The maximum area MP may be determined in various shapes according to the distance between the surgical target bone and the cutting start position Ps, the entry direction / posture of the surgical robot 100, the characteristics of the surgical target bone and the implant, and the like.

[0071] The size of the maximum area MP is larger than the size of the implant and the surgical target bone. Further, corresponding to the cutting start position Ps, a plurality of maximum areas MP may be set, and the plurality of maximum areas MP may have overlapping areas.

[0072] Reference Figure 7 , when two cutting starting positions Ps_1 and Ps_2 and the entry directions ed_1 and ed_2 / postures corresponding to the cutting starting positions Ps_1 and Ps_2 are determined for a cutting surface, a first maximum area MP_1 corresponding to the first cutting starting position Ps_1 and a second maximum area MP_2 corresponding to the second cutting starting position Ps_2 can be generated respectively. In this case, Figure 7 As shown, the first maximum area MP_1 and the second maximum area MP_2 may have some overlapping areas.

[0073] For reference, Figure 3 The flowchart discloses that the maximum area is generated after the safe area and the free cutting area are generated, but is not limited to this order. Of course, the safe area and the free cutting area can also be generated after the maximum area is generated.

[0074] Next, the processor 340 generates a revised three-dimensional model, in which the state in which the cutting surface has been virtually cut is reflected in the revised three-dimensional model (S60). The revised three-dimensional model refers to a three-dimensional model generated by predicting the state of each cutting surface after cutting based on the three-dimensional model of the surgical target bone before cutting, although the surgical target bone is not actually cut by the surgical robot 100. The revised three-dimensional model can be generated by predicting the virtual cutting state of each cutting surface, wherein the prediction is based on the characteristics of the implant to be installed in the surgical target bone (such as the position and posture of the implant, the shape and size of the implant) and the cutting characteristics of the cutting tool used to perform the cutting (such as the depth and cutting width of a single cut).

[0075] Taking into account the planned cutting order of one or more cutting surfaces, revised three-dimensional models corresponding to the number of cutting surfaces can be generated respectively. Taking into account the cutting order, when another cutting surface has been cut before cutting the current cutting surface, a revised three-dimensional model can be generated, wherein the cutting state of the current cutting surface includes the cut state of the other cutting surface. Therefore, for the first cutting surface to be cut first, a first revised three-dimensional model will be generated, in which the virtual cutting state of the first cutting surface is reflected according to the initial three-dimensional model of the surgical target bone. In the case where the revised three-dimensional model does not correspond to the first cutting surface, each revised three-dimensional model is generated in sequence, wherein in the revised three-dimensional model, the virtual cutting state of the current cutting surface is additionally reflected based on the revised three-dimensional model that has cumulatively reflected the cutting surfaces previously cut in the cutting order, that is, based on the revised three-dimensional model that has been generated immediately before.

[0076] Next, the processor 340 creates a cutting path of the surgical robot 100 starting from the cutting start position within the range of the maximum area according to the corrected three-dimensional model (S70). A cutting path can be created separately for each cutting surface corresponding to the number of cutting surfaces to be cut when installing the implant, and the cutting path can be variously defined as a straight line, a curve, or a combination thereof. The cutting path can include not only the motion path of the surgical robot 100, but also the posture information of the surgical robot 100 on the path.

[0077] Figure 8 is a flowchart showing how the cutting path planning apparatus 300 creates a cutting path for the surgical robot 100 according to an embodiment of the present disclosure. Figures 9 to 13 is a reference view for explaining the cutting path planning device 300 according to the embodiment of the present disclosure to create a cutting path for the surgical robot 100. Figures 8 to 13 describe Figure 3 Detailed operation of step S70 in FIG.

[0078] First, the processor 340 identifies the outer boundary OL of the cutting surface in the modified three-dimensional model (S710). The processor 340 can identify the outer boundary OL of the cutting surface by identifying the outermost edge of the surgical target bone on the cutting surface in the modified three-dimensional model corresponding to the cutting surface, so as to create a cutting path for each cutting surface.

[0079] Next, the processor 340 sets the cutting margin area ML by applying a predetermined offset starting from the outer boundary OL of the cutting surface (S720). Fig. 9 The cutting margin area ML refers to an area excluded from cutting to protect soft tissue, and can be set to be an area located inside the surgical target bone and a predetermined distance from the outer boundary OL. A preset value can be applied to the offset size of the intrabone position, and the preset value can be set to change according to the type of cutting tool.

[0080] Next, the processor 340 determines the security region R set in the previous step. s and free cutting area R f As well as the outer boundary OL of the cutting surface and the cutting margin area ML, a cutting path creation area CR for creating a cutting path is determined (S730). The cutting path creation area CR refers to the range in which the cutting path is actually generated, and the cutting path is generated so that all cutting is performed within the cutting path creation area CR.

[0081] Fig.10 and Fig.11 1 and 2 are reference views for explaining the setting of the cutting path creation area by the cutting path planning device 300 according to an embodiment of the present disclosure, and these reference views are respectively a first example and a second example of the cutting path creation area CR set by the cutting path planning device 300.

[0082] Reference Fig.10 and Fig.11 , the cutting path creation area CR is determined to satisfy the following conditions. The cutting path creation area CR includes the cutting start position Ps as a vertex, the cutting path creation area CR is defined within the maximum area MP, and the cutting path creation area CR is determined not to invade the safety area Rs. In addition, the cutting path creation area CR is basically created where the cutting margin area ML does not overlap with the safety area Rs without passing through the boundary of the cutting margin area ML, but the cutting path creation area CR can be created to include the outer boundary of the bone without being restricted by the cutting margin area ML in the free cutting area Rf.

[0083] In addition, if Fig.11As shown, the cutting path creation areas CR_1 and CR_2 may be generated separately corresponding to the cutting start positions Ps_1 and Ps_2, respectively. In this case, considering that a plurality of cutting path creation areas CR_1 and CR_2 overlap each other, the cutting path creation areas CR_1 and CR_2 may be generated to minimize the overlapping area, or the cutting path creation areas CR_1 and CR_2 may be modified by the user. This is to prevent the cutting path from being repeatedly created for the overlapping area of ​​the cutting path creation areas.

[0084] When the cutting path creation area CR is generated, the processor 340 creates a cutting path for the surgical robot 100 with the cutting path creation area CR as a boundary (S740). The generation of the cutting path can start from the cutting start position, and the cutting path can include a return position of the surgical robot 100 to return to the cutting start position after cutting.

[0085] Fig.12 and Fig.13 These are reference views for illustrating that the cutting path planning device 300 according to an embodiment of the present disclosure creates a cutting path based on a cutting path creation area, and these reference views are respectively a first example and a second example of a cutting path CutP created by the cutting path planning device 300.

[0086] Reference Fig.12 and Fig.13 , a cutting path CutP is created so as to cut all areas within the cutting path creation area CR. The cutting path CutP starts from the cutting start position Ps and is created to reflect the entry direction / posture of the surgical robot 100. In addition, the path interval, etc. may vary according to the type of cutting tool used for cutting and the characteristics of the cutting tool (such as the depth of one cut, the cutting width, etc.).

[0087] The processor 340 may determine whether the surgical robot 100 is able to perform cutting on all areas within the cutting path creation area CR within a predetermined posture range by considering the characteristics of the surgical robot 100 (e.g., the posture change range and the motion range of the robot arm of the surgical robot 100) and the characteristics of the cutting tool. If the surgical robot 100 cannot perform cutting on all areas within the cutting path creation area CR with one posture or posture change within the predetermined range, a cutting path CutP may be created so that the surgical robot 100 can cut certain areas within the cutting path creation area CR, then return to the cutting start position Ps, and complete the cutting by changing the posture and entering the cutting start position again. Fig.12The following example is shown, that is, creating a cutting path CutP so that the surgical robot 100 can perform cutting, return to the cutting starting position Ps from p1, re-enter p2 from the cutting starting position Ps, perform subsequent cutting on the area that has not been cut, and finally return to the cutting starting position Ps from p3 after completing the cutting.

[0088] Fig.13 The following example is shown, that is, corresponding to the multiple cutting path creation areas CR_1 and CR_2, the cutting paths CutP_1 and CutP_2 are created separately. In this way, when a cutting surface is divided into cutting areas to create cutting paths, the cutting order of the divided cutting areas can also be determined together. Fig.13 The following example is shown, that is, creating a first cutting path CutP_1, starting from the first cutting starting position Ps_1, completing the cutting of a portion of the first cutting path creation area CR_1, and initially returning to p11, and then creating a second cutting path CutP_2, moving the surgical robot 100 to the second cutting starting position Ps_2, completing the cutting of the second cutting path creation area CR_2, and finally returning to p22.

[0089] In this case, if Fig.13 As shown, the cutting path is created so that the surgical robot 100 does not repeatedly pass through part or all of the overlapping area between the first cutting path creation area CR_1 and the second cutting path creation area CR_2. In order to prevent the surgical robot 100 from moving unnecessarily after the overlapping area has been cut by the cutting path corresponding to one of the cutting path creation areas, the cutting path can be created so that cutting can be started from a portion that has not yet been cut.

[0090] Although Fig.12 and Fig.13 An example of creating a cutting path based on a combination of straight line paths is shown, but the shape of the cutting path can be variously defined in the form of a straight line, a curve, or a combination thereof as described above. For example, when the skin incision area is very narrow so that a straight line movement in the left and right directions is difficult to cut, Fig.12 and Fig.13 When the entire area shown needs to be cut, the cutting path can be created in the form of a left-right motion arc rotating around a specific location.

[0091] For reference, Figures 4 to 13 Planning of the cutting path for one cutting plane is shown, but the cutting path can be planned even for other cutting planes in the same way.

[0092] The above-mentioned planning of the cutting path of the surgical robot can be performed in the preoperative planning step before the operation, or in the planning change step during the operation. For reference, when the planning of the cutting path is performed in the planning change step during the operation, the cutting paths of all cutting surfaces can be planned at one time and then the cutting can be performed, or a cutting path can be created for each cutting surface and the cutting of the corresponding cutting surface can be performed at the same time.

[0093] As described above, the cutting path of the surgical robot 100 is planned based on the implant coordinate system, and the surgical robot 100 is operated based on the surgical robot coordinate system, so these coordinate systems need to go through a matching process.

[0094] Fig.14 is a reference view used to illustrate the coordinate transformation process of the cutting path according to an embodiment of the present disclosure so as to use the planned cutting path for robotic surgery.

[0095] As described above, in a robotic surgical system 1 including a robot marker RM mounted on a robot, a bone marker BM mounted on a bone, and a tracking device 200 for tracking the positions and postures of these markers RM and BM, the following formula 1 can be used to derive a transformation matrix for coordinate transformation between an implant coordinate system and a robot coordinate system.

[0096]

[0097] here, is the transformation matrix between the robot coordinate system and the implant coordinate system, is the transformation matrix between the robot coordinate system and the coordinate system of the robot marker RM, is the transformation matrix between the coordinate system of the tracking device 200 and the coordinate system of the robot marker RM, is the transformation matrix between the coordinate system of the tracking device 200 and the coordinate system of the bone marker BM, is the transformation matrix between the coordinate system of the bone marker BM and the coordinate system of the bone B, It is the transformation matrix between the coordinate system of bone B and the coordinate system of the implant.

[0098] Since how to derive the transformation matrix for coordinate transformation between heterogeneous coordinate systems during robotic surgery is well known, a detailed description thereof will be omitted for the sake of brevity.

[0099] The processor 340 can check whether the planned cutting path of the surgical robot 100 belongs to the surgical area set on the surgical robot coordinate system according to the coordinate system transformation matrix calculated as above. The surgical area refers to an area that the surgical robot 100 can enter without worrying about the occurrence of strange phenomena during the operation, and by considering the position and posture of the surgical robot 100 and the kinematic range of the surgical robot 100, the surgical area can be preset to various three-dimensional shapes such as a sphere, a rectangular parallelepiped, a cube, etc.

[0100] When the cutting path defined based on the implant coordinate system does not belong to the surgical area, the processor 340 can issue a notification through the display unit 320 and guide the adjustment direction, etc., to adjust the position and posture of the surgical robot 100 and the position of the patient, etc., so that the cutting path can belong to the surgical area.

[0101] As described above, by adopting the cutting path planning device 300 and method thereof according to the present disclosure, a cutting path suitable for the patient can be automatically created by considering the diversity of the bones of each patient, thereby improving the surgical effect, and the cutting path is created to minimize the residual bone area remaining after the surgical robot cuts, thereby simplifying the surgical process and effectively preventing surgical delays.

[0102] Although all the elements of the embodiment of the present disclosure are combined together as one element or operated as a combination, the present disclosure is not limited to this embodiment. In other words, as long as it belongs to the scope of the present disclosure, one or more elements of all the elements can be selectively combined and operated. In addition, all the elements can be implemented by independent hardware respectively, or some or all of the elements can be selectively combined to be implemented as a computer program, and the computer program has a program module, and the program module can execute the functions of some or all combinations from one or more hardware. The code and code segments constituting the computer program are easily derived by those skilled in the art. Such a computer program is stored in a computer-readable medium, and is read and executed by a computer, thereby realizing the embodiment of the present disclosure. The storage medium of the computer program may include a magnetic recording medium, an optical recording medium, etc.

[0103] In addition, the terms "including", "configuration" and / or "having" indicate the presence of the components, unless there is an obviously different meaning in the present disclosure, but do not exclude their presence, and should be interpreted as further including other components. Unless otherwise defined, all terms (including technical or scientific terms) used in this document have the same meanings as commonly understood by those skilled in the art related to the present disclosure. General terms defined in dictionaries should be interpreted as having a meaning consistent with the relevant technical context, and will not be interpreted as having an idealistic or overly formalistic meaning unless clearly defined in the present disclosure.

[0104] The foregoing description is merely an example of the technical ideas of the present disclosure, and a person with ordinary knowledge of the technology involved in the present disclosure can make various modifications and changes without departing from the basic characteristics of the present disclosure. Therefore, the embodiments of the present disclosure are not intended to limit but to describe the technical ideas of the present disclosure, and the scope of the technical ideas of the present disclosure is not limited by these embodiments. The scope of the present disclosure should be interpreted according to the attached claims, and all technical ideas within the equivalent scope should be interpreted as falling within the scope of the present disclosure.

Claims

1. A method for planning a cutting path of a surgical robot, the method being performed by a surgical robot cutting path planning device, the method include: Determining the position and posture of an implant to be installed in the surgical target bone according to the three-dimensional model of the surgical target bone; Determining a cutting surface of the surgical target bone that needs to be cut to install the implant; Determining a cutting start position at which the surgical robot starts cutting the cutting surface, and an entrance direction of the surgical robot at the cutting start position; According to the cutting start position and the entry direction, setting a maximum area in which the cutting path of the surgical robot can be defined; generating a modified three-dimensional model, wherein the modified three-dimensional model reflects the virtual cutting state of the cutting surface; as well as The cutting path of the surgical robot starting from the cutting start position is created within the range of the maximum area according to the corrected three-dimensional model.

2. The method according to claim 1, further comprising setting a safety zone to protect tissue around the surgical target bone, The cutting path is created such that no cutting is performed within the safety area.

3. The method according to claim 2, in, determining one or more cutting starting positions of the surgical robot for the cutting surface according to the preset skin incision information for the cutting of the cutting surface and the position of the safety area, and Corresponding to each cutting start position, the maximum area and the cutting path are determined individually.

4. The method according to claim 1, in, According to the number of the cutting surfaces that need to be cut to install the implant, the cutting path is created separately for each cutting surface.

5. The method according to claim 1, further comprising: include: According to the position of the tissue around the surgical target bone and the preset skin incision information, a free cutting area where the surgical robot can freely perform cutting is set.

6. The method according to claim 1, in, The step of creating the cutting path of the surgical robot comprises: identifying an outer boundary of the cutting surface in the modified three-dimensional model; setting a cutting margin area excluded from the cutting by applying a predetermined offset from the outer boundary; Determining a cutting path creation area for creating the cutting path according to the maximum area and the cutting margin area; and The cutting path is created with the cutting path creation area as a boundary.

7. The method according to claim 6, further comprising determining whether the surgical robot can perform cutting on all areas within the cutting path creation area within a predetermined posture range, in, The creation of the cutting path includes: once cutting is not performed on all areas within the cutting path creation area within the predetermined posture range, the cutting path is created to enable the surgical robot to cut some areas within the cutting path creation area, and then return to the cutting starting position, and complete the cutting by changing the posture and entering the cutting starting position again.

8. The method according to claim 6, in, Determining one or more cutting starting positions of the surgical robot for the cutting surface according to preset skin incision information for cutting the cutting surface and the position of the safety area; as well as Corresponding to the multiple cutting start positions, multiple cutting path creation areas are determined respectively.

9. The method according to claim 1, in, The creating the cutting path of the surgical robot includes: determining a return position of the surgical robot to return to the cutting start position after the cutting.

10. The method according to claim 1, in, The cutting path is determined according to the type of the cutting tool of the surgical robot and the cutting characteristics of the cutting tool.

11. The method according to claim 1, in, Determining the position and posture of the implant comprises: The position and the posture of the implant are determined based on a user input via a user interface unit.

12. A surgical robot cutting path planning device, used for planning a cutting path of a surgical robot, the device comprising a processor, The processor is configured to: Determining the position and posture of an implant to be installed in the surgical target bone according to the three-dimensional model of the surgical target bone; Determining a cutting surface of the surgical target bone that needs to be cut to install the implant; Determining a cutting start position at which the surgical robot starts cutting the cutting surface, and an entrance direction of the surgical robot at the cutting start position; According to the cutting start position and the entry direction, setting a maximum area in which the cutting path of the surgical robot can be defined; generating a modified three-dimensional model, wherein the modified three-dimensional model reflects the virtual cutting state of the cutting surface; as well as The cutting path of the surgical robot starting from the cutting start position is created within the range of the maximum area according to the corrected three-dimensional model.

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