Navigation system, jig, and program

Abstract

A navigation system is provided with: an acquisition unit that acquires information on the position and orientation of a first sensor detected on the basis of a signal from the first sensor, and information on the target mounting position and target mounting orientation of the first sensor with respect to the position and orientation of a second sensor detected on the basis of a signal from the second sensor, and a first sensor inserted into the mounting portion of the first jig in a first orientation predetermined with respect to the first jig, the first jig having a surface of a shape corresponding to the surface of the first bone, and a second sensor inserted into the mounting portion of the second jig in a second orientation predetermined with respect to the second jig, the second clamp is provided with a surface corresponding to the surface of the second bone in shape; a derivation unit that derives a first relative position and a first relative orientation of the first sensor on the basis of the target mounting position and the target mounting orientation and the position and orientation of the first sensor; an information generation unit that generates an image of a three-dimensional coordinate axis indicating the target mounting position and the target mounting orientation, and an image of a three-dimensional coordinate axis indicating the first relative position and the first relative orientation; and a display unit that displays an image of the three-dimensional coordinate axis.

Description

Technical Field

[0001] The invention relates to a navigation system, a fixture and a program. Background Art

[0002] With the advancement of image processing technology, preoperative planning (3D simulation) before surgery has become popular. In addition, for example, in orthognathic surgery, the operator sometimes separates the maxilla (Le Fort I type fracture fragment) from the skull. The operator accurately moves the maxilla to the target relative position relative to the skull position and fixes the maxilla to the skull again at the target relative position.

[0003] In the preoperative planning of such orthognathic surgery, the patient's skull model and maxillary model are moved and rotated on the screen of the display unit of the planning device (information processing device), and the planner (doctor) studies the target relative position of the maxillary bone with respect to the actual skull position so that the patient can obtain a good bite and a beautiful appearance.

[0004] Navigation surgery is a method of reflecting the results of the relative position of the target planned before surgery in the actual surgery. In optical navigation surgery, the position of the surgical instrument is detected in real time by measuring the distance using infrared rays reflected by a reflector attached to the surgical instrument.

[0005] In addition, research is underway to apply magnetic (EM: Electromagnetic) navigation surgery to sinus surgery and catheter therapy, etc. In magnetic navigation surgery, the position of a surgical instrument (non-magnetic body) is detected in real time by a magnetic tracking system based on the output of a magnetic sensor mounted on the surgical instrument (non-magnetic body) (see Non-Patent Document 1).

[0006] Patent Document 1 discloses a surgical system that performs optical navigation or magnetic navigation in craniomaxillofacial surgery. Patent Document 2 discloses an optical maxillary alignment system that uses a dental brace-type target and a camera.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: U.S. Patent Application Publication No. 2017 / 0000505

[0010] Patent Document 2: U.S. Patent Application Publication No. 2009 / 0220122

[0011] Non-patent literature

[0012] Non-patent document 1: “Magnetic three-dimensional measurement system AURORA”, [online], August 2, 2022, Advanced Systems Co., Ltd., [retrieved on August 2, 2022], Internet <URL: http: / / www.asco.jp / 02aurora.htm> Summary of the invention

[0013] Problems to be solved by the invention

[0014] However, Patent Document 1 discloses a position detection reference module having a complex shape as a detection reference module used in a magnetic navigation system. This leads to a problem in that the position detection reference module having a complex shape may become an obstacle during surgery. In addition, the position detection reference module having a shape exposed to the outside detects a position away from the actual bone position as the position of the bone. Therefore, even if the bone is accurately moved to the position guided by the navigation system, since the position is not the accurate target position, there is a problem that the operator cannot align the position of the bone with the accurate target position.

[0015] Furthermore, in Patent Document 1, a position detection reference module for detecting the position of a bone fragment to be moved is mounted on a cutting guide for separating the jaw from the skull. When such a cutting guide is used, there is a problem that the alignment of the maxilla and the mandible is very time-consuming, and there are often no obvious marks on the bones for alignment, so it is difficult to visually set the sensor at the target installation position determined in the preoperative planning. Therefore, it is not recommended to mount the position detection reference module on the cutting guide.

[0016] In Patent Document 2, a braces-type dentition splint (braces) is used to align the maxillary bone. In such an alignment operation, it is preferred that the maxillary bone and the mandibular bone are integrated. However, in order to enable distance measurement with a camera, the shape of the target having four light sources for alignment is exposed to the outside from the dentition splint, like the position detection reference module of Patent Document 1. Therefore, not only does the target become an obstacle to the operation, but also because the target is far from the dentition position, it is sometimes impossible to accurately align the bones with each other. In addition, since the target is exposed to the outside from the dentition splint, the position of the target serving as the alignment origin is sometimes offset, making it difficult to accurately align the bones with each other.

[0017] In addition, in Patent Document 2, sometimes the surgeon and the caregiver gather around the patient's head. In such a case, in an optical navigation surgery using a reflector exposed to the outside of the dental splint as in Patent Document 2, optical shielding may occur due to the surgeon or the like. That is, the infrared rays reflected by the reflector mounted on the surgical instrument may be shielded by the surgeon or the like. In the case of optical shielding, the infrared rays cannot be used for distance measurement, and therefore the position of the surgical instrument cannot be detected. For example, when a reflector is mounted on the bones of a patient undergoing surgery, such a situation may also occur.

[0018] In contrast, in the magnetic navigation surgery described in non-patent document 1, the position of the surgical instrument or bone is detected based on the output of a small magnetic sensor mounted on the surgical instrument or bone. Therefore, in the magnetic navigation surgery, optical occlusion does not occur. For these reasons, the application of magnetic navigation surgery using a small magnetic sensor to the field of oral surgery has been studied.

[0019] However, even if the magnetic navigation surgery described in Non-Patent Document 1 is applied to orthognathic surgery, if the alignment is performed according to the installation position of the magnetic sensor installed on the bone, the position of the maxillary bone and the position of the skull will deviate due to the lack of marks on the bone, as in Patent Document 1. This will cause a problem that it is difficult to assist the surgeon to accurately move and rotate the bone so that the bone is in the target relative position and target relative posture predetermined in the preoperative planning.

[0020] Thus, there is no mark on the bones of the patient who is to undergo orthognathic surgery to indicate the position where the reflector and the magnetic sensor are installed by screws. Therefore, there is a problem that the operator cannot visually grasp the exact position (target installation position) where the sensor should be installed on the patient's bones. Furthermore, in the navigation that presents the target relative position to the operator in numerical form as in Patent Document 1, there is a problem that the operator cannot intuitively grasp whether the bones are accurately moved and rotated so that the relative position and relative posture of the bones become the target relative position and target relative posture.

[0021] In view of the above situation, the object of the present invention is to provide a navigation system, a fixture and a program that can assist the surgeon to accurately move and rotate bones so that the relative position and relative posture of the bones become the target relative position and target relative posture.

[0022] Solutions for solving problems

[0023] One embodiment of the present invention relates to a navigation system, comprising: an acquisition unit, which acquires information on the position and posture of the first sensor detected based on a signal of a first sensor, and information on a target installation position and a target installation posture of the first sensor relative to the position and posture of the second sensor detected based on a signal of a second sensor, wherein the first sensor is inserted into the installation portion of the first fixture in a first orientation predetermined relative to the first fixture, the first fixture has a surface having a shape corresponding to the surface of a first bone, and the second sensor is inserted into the installation portion of the second fixture in a second orientation predetermined relative to the second fixture, the second fixture has a surface having a shape corresponding to the surface of a second bone; a derivation unit, which derives a first relative position and a first relative posture of the first sensor relative to the target installation position and the target installation posture based on the target installation position and the target installation posture and the position and posture of the first sensor; an information generation unit, which generates an image of three-dimensional coordinate axes representing the target installation position and the target installation posture and an image of three-dimensional coordinate axes representing the first relative position and the first relative posture; and a display unit, which displays an image of the three-dimensional coordinate axes representing the target installation position and the target installation posture and an image of the three-dimensional coordinate axes representing the first relative position and the first relative posture.

[0024] One embodiment of the present invention relates to a navigation system comprising: an acquisition unit, which acquires information on the position and posture of a first bone detected based on a signal of a first sensor and information on the position and posture of a second bone detected based on a signal of a second sensor, wherein the first sensor is inserted into the mounting portion of the first fixture in a first orientation predetermined relative to the first fixture, the first fixture has a surface with a shape corresponding to the surface of the first bone, and the second sensor is inserted into the mounting portion of the second fixture in a second orientation predetermined relative to the second fixture, the second fixture has a surface with a shape corresponding to the surface of the second bone; and a derivation unit, which, based on the information on the position and posture of the first bone and the information on the position and posture of the second bone The present invention relates to a device for deriving a target relative position and a target relative posture of the second bone relative to the position and posture of the first bone based on information of the relative position of the second bone, and deriving a target relative position and a target relative posture of the second bone relative to the position and posture of the first bone based on a predetermined amount of movement relative to an initial value of the relative position and a predetermined amount of rotation relative to an initial value of the relative posture; an information generating unit, which generates an image of three-dimensional coordinate axes representing the target relative position and the target relative posture and an image of three-dimensional coordinate axes representing the relative position and the relative posture; and a display unit, which displays the image of the three-dimensional coordinate axes representing the target relative position and the target relative posture and an image of the three-dimensional coordinate axes representing the relative position and the relative posture.

[0025] One aspect of the present invention relates to a jig having: a mounting portion into which a sensor is inserted in a predetermined orientation; and a surface having a shape corresponding to a surface of a bone to be joined.

[0026] One embodiment of the present invention relates to a program for causing a computer to perform the following steps: obtaining information on the position and posture of the first sensor detected based on a signal of the first sensor and information on a target installation position and a target installation posture of the first sensor relative to the position and posture of the second sensor detected based on a signal of the second sensor, wherein the first sensor is inserted into the installation portion of the first fixture in a first orientation predetermined relative to the first fixture, the first fixture having a surface having a shape corresponding to the surface of the first bone, and the second sensor is inserted into the installation portion of the second fixture in a second orientation predetermined relative to the second fixture, the second fixture having a surface having a shape corresponding to the surface of the second bone; deriving a first relative position and a first relative posture of the first sensor relative to the target installation position and the target installation posture based on the target installation position and the target installation posture and the position and posture of the first sensor; generating an image of three-dimensional coordinate axes representing the target installation position and the target installation posture and an image of three-dimensional coordinate axes representing the first relative position and the first relative posture; and displaying an image of three-dimensional coordinate axes representing the target installation position and the target installation posture and an image of three-dimensional coordinate axes representing the first relative position and the first relative posture.

[0027] One embodiment of the present invention relates to a program for causing a computer to perform the following steps: obtaining information on the position and posture of a first bone detected based on a signal of a first sensor and information on the position and posture of a second bone detected based on a signal of a second sensor, wherein the first sensor is inserted into the mounting portion of the first fixture in a first orientation predetermined relative to the first fixture, the first fixture having a surface having a shape corresponding to the surface of the first bone, and the second sensor is inserted into the mounting portion of the second fixture in a second orientation predetermined relative to the second fixture, the second fixture having a surface having a shape corresponding to the surface of the second bone; deriving a relative position and relative posture of the second bone relative to the position of the first bone based on the information on the position and posture of the first bone and the information on the position and posture of the second bone, and deriving a target relative position and target relative posture of the second bone relative to the position and posture of the first bone based on a predetermined amount of movement relative to an initial value of the relative position and a predetermined amount of rotation relative to an initial value of the relative posture; generating an image of three-dimensional coordinate axes representing the target relative position and the target relative posture and an image of three-dimensional coordinate axes representing the relative position and the relative posture; and displaying an image of three-dimensional coordinate axes representing the target relative position and the target relative posture and an image of three-dimensional coordinate axes representing the relative position and the relative posture.

[0028] Effects of the Invention

[0029] According to the present invention, it is possible to assist the operator in accurately moving and rotating the bones so that the relative position and relative posture of the bones become the target relative position and target relative posture. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a diagram showing a configuration example of a navigation system in the first embodiment.

[0031] Figure 2 It is a figure which shows the skull model and the maxillary bone model in the first embodiment.

[0032] Figure 3 It is a diagram showing an example of the position and posture of the maxillary bone model before and after the movement in the first embodiment.

[0033] Figure 4 It is a diagram showing an example of determining the translation parameter and the rotation parameter (rotation matrix) in the first embodiment.

[0034] Figure 5 It is a diagram showing an example of specifying the mounting position of the magnetic sensor in the first embodiment.

[0035] Figure 6It is a figure which shows an example of the clamp which is joined to the skull in the first embodiment.

[0036] Figure 7 This is a diagram showing an example of a jig that engages with the dentition of the maxillary bone in the first embodiment.

[0037] Figure 8 It is a diagram showing an example of a navigation image indicating an installation position in the first embodiment.

[0038] Fig. 9 It is a diagram showing an example of a navigation image indicating an installation position in the first embodiment.

[0039] Fig.10 It is a diagram showing an example of mounting the magnetic sensor in the first embodiment.

[0040] Fig.11 This is a diagram showing an example of a navigation image showing the position of a skeleton and the like in the first embodiment.

[0041] Fig.12 This is a diagram showing an example of a navigation image showing the position of a skeleton and the like in the first embodiment.

[0042] Fig.13 This is a flowchart showing a first operation example of the navigation device in the first embodiment.

[0043] Fig.14 This is a flowchart showing a second operation example of the navigation device in the first embodiment.

[0044] Fig.15 It is a diagram showing a first example of specifying the mounting positions of the magnetic sensors in the second embodiment.

[0045] Fig.16 It is a diagram showing an example of bone cutting in the second embodiment.

[0046] Fig.17 This is a diagram showing an example of the attachment position of each magnetic sensor after bone section in the second embodiment. DETAILED DESCRIPTION

[0047] Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0048] (First Embodiment)

[0049] Figure 1: is a diagram showing a structural example of a navigation system 1 (surgical assistance system) in the first embodiment. The navigation system 1 is a system for navigating the relative position and relative posture of a navigation sensor with respect to a target installation position and a target installation posture predetermined on the patient's skeleton. Thus, the operator (doctor) can accurately install the sensor (clamp) on the patient's skeleton so that the posture of the sensor becomes the target installation posture at the target installation position predetermined on the patient's skeleton. The target installation position and the target installation posture are predetermined by the planner (doctor) in preoperative planning (three-dimensional simulation performed before surgery).

[0050] The sensor installed on the patient's bone can be a light source or reflector used in optical navigation surgery, or a magnetic sensor used in magnetic navigation surgery. Since no optical occlusion occurs, a magnetic sensor is more preferred. Below, as an example, the operator installs the magnetic sensor on the patient's bone.

[0051] In addition, the navigation system 1 is a system for navigating the relative position and relative posture of the patient's bones relative to a predetermined target relative position and target relative posture. Thus, the surgeon can make the relative position and relative posture of the second bone relative to the position and posture of the first bone become the predetermined target relative position and target relative posture. The target relative position and target relative posture are predetermined by the planner in preoperative planning.

[0052] The navigation system 1 includes a planning device 2, a storage device 3, a communication line 4, a detection device 5, and a navigation device 6. The clamp 210 (first clamp) and the magnetic sensor 301-1 (first sensor) correspond to the patient's bone 101 (first bone). In addition, the clamp 220 (second clamp) and the magnetic sensor 301-2 (second sensor) correspond to the patient's bone 102 (second bone).

[0053] In an embodiment of the present invention, the fixture 220 is preferably a dental brace (dental splint). The magnetic sensor 301-2 is mounted on the bone 102 using the fixture 220. Since the joint surface of the fixture 220 is manufactured in a manner suitable for the shape of the dentition, the operator can accurately set the magnetic sensor 301-2 at the target installation position determined on the bone. In an embodiment of the present invention, the position of the fixture 220 that can accurately set the sensor at the target installation position determined on the bone is set as the origin, and the target relative position and the target relative posture are determined relative to the origin, so that the operator can align the position of the bone to the accurate position. In addition, as long as the magnetic sensor 301-2 can be accurately set at the target installation position determined on the bone, the fixture 220 may not be a dental brace.

[0054] In addition, the planning device 2 only needs to be included in the navigation system 1 during preoperative planning, and may not be included in the navigation system 1 during surgery.

[0055] The planning device 2 (preoperative planning device) includes a movement processing unit 21, a rotation processing unit 22, a display unit 23, and a conversion unit 24. The movement processing unit 21 and the rotation processing unit 22 may be integrated (movement rotation processing unit). The detection device 5 includes a magnetic field generating unit 51, an acquisition unit 52, a detection unit 53, and a communication unit 54. The navigation device 6 includes a communication unit 61, a storage unit 62, an acquisition unit 63, a derivation unit 64, an information generating unit 65, and a display unit 66.

[0056] Some or all of the functional units of the planning device 2 and the navigation device 6 are implemented as software by a processor such as a CPU (Central Processing Unit) executing a program stored in a storage unit having a non-volatile recording medium (non-temporary recording medium). In addition, some of the functional units of the detection device 5 are implemented as software by a processor executing a program stored in a storage unit having a non-volatile recording medium (non-temporary recording medium).

[0057] The program may also be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a removable medium such as a floppy disk, a magneto-optical disk, a ROM (Read Only Memory), a CD-ROM (Compact Disc Read Only Memory), a hard disk built into a computer system, a non-temporary recording medium such as a storage device such as a solid state drive (SSD).

[0058] Part or all of the functional units of the planning device 2 and the navigation device 6 may be implemented, for example, using hardware including an electronic circuit (electronic circuit or circuitry: electronic circuit or electronic system) using LSI (Large Scale Integrated circuit: large scale integrated circuit), ASIC (Application Specific Integrated Circuit: application specific integrated circuit), PLD (Programmable Logic Device: programmable logic device) or FPGA (Field Programmable Gate Array: field programmable gate array). In addition, part of the functional units of the detection device 5 may also be implemented, for example, using hardware including an electronic circuit using LSI, ASIC, PLD or FPGA.

[0059] Bone 101 and bone 102 are bones of the patient, respectively. Hereinafter, as an example, bone 101 (first bone) is the skull (facial bone) of the patient. In addition, as an example, bone 102 (second bone) is the maxilla (LeFort I type fracture block) separated from bone 101.

[0060] <Determination of the Target Relative Position and Target Relative Posture of the Skeleton 102 Before Surgery>

[0061] Before surgery, a planner (not shown) performs preoperative planning using the planning device 2. For example, in preoperative planning performed before orthognathic surgery (Le Fort I osteotomy), a skull model (a three-dimensional model of the skeleton 101) is created in the memory of the planning device 2 based on data acquired by performing a CT (computed tomography) scan on the patient.

[0062] Based on the skull model, an image of the skull model is displayed on the screen of the display unit 23. In addition, the maxillary model (three-dimensional model of the skeleton 102) is separated from the skull model on the screen. Thus, each image of the separated maxillary model and the skull model is displayed on the screen of the display unit 23. According to the operation performed by the planner (for example, mouse operation), the relative position (movement amount) and relative posture (rotation amount) of the maxillary model relative to the skull model are studied, so as to obtain a good bite and a beautiful appearance for the patient.

[0063] Here, the movement processing unit 21 moves the maxillary bone model on the screen according to the operation performed by the planner. The planner determines the movement amount (X-axis component amount, Y-axis component amount, Z-axis component amount) relative to the initial value of the position of the maxillary bone model by confirming the movement amount of the maxillary bone model on the screen. Thus, the planner can determine the movement amount relative to the initial value of the actual position of the skeleton 102. The movement processing unit 21 records the information of the movement amount determined by the planner in the storage device 3.

[0064] The rotation processing unit 22 may also rotate the three-dimensional model of the maxillary model on the screen according to the operation performed by the planner. The planner determines the rotation amount relative to the initial value of the position of the maxillary model by confirming the rotation amount (roll axis component amount, pitch axis component amount, yaw axis component amount) of the maxillary model on the screen. Thus, the planner can determine the rotation amount relative to the initial value of the actual position of the skeleton 102. The rotation processing unit 22 records the information of the rotation amount determined by the planner in the storage device 3.

[0065] <Decide the location of the sensor to be attached to the bone using a clamp before surgery>

[0066] In preoperative planning, the planner specifies the target installation position of the magnetic sensor 301-1 (jig 210) in the bone 101 to the conversion unit 24. When the bone 101 is a skull, the target installation position is, for example, a position determined at the lateral edge of the piriform aperture of the skull.

[0067] The planner specifies the target installation position of the magnetic sensor 301-1 on the screen of the display unit 23 while the maxillary bone model is not separated from the cranial bone model. The planner may also specify the target installation position of the magnetic sensor 301-1 on the screen of the display unit 23 while the maxillary bone model is separated from the cranial bone model.

[0068] The planner joins the model of the fixture 220 (braces) to the dentition of the maxillary model on the screen of the display unit 23, and the maxillary model is moved and rotated to the target relative position and target relative posture relative to the skull model. The planner specifies the target installation position of the magnetic sensor 301-1 (fixture 210) in the skull model on the screen, for example, by operating the mouse. Thereby, the planner can input the target installation position of the magnetic sensor 301-1 in the actual skeleton 101 into the conversion unit 24. In an embodiment of the present invention, the target installation position of the magnetic sensor 301-1 is represented by taking the specified position of the fixture 220 joined to the dentition of the maxillary model as the origin.

[0069] The conversion unit 24 converts the first position (first two-dimensional position information) specified by the planner on the surface of the skull model into three-dimensional position information using the screen (two-dimensional) of the display unit 23. The three-dimensional position information is equivalent to the target installation position of the magnetic sensor 301-1 (fixture 210) in the actual skeleton 101. The conversion unit 24 records the three-dimensional position information of the target installation position of the magnetic sensor 301-1 in the storage device 3.

[0070] In addition, the conversion unit 24 may also convert the second position (second two-dimensional position information) specified by the planner on the surface of the maxillary bone model into three-dimensional position information using the screen (two-dimensional) of the display unit 23. The three-dimensional position information is equivalent to the target installation position of the magnetic sensor 301-2 (fixture 220) in the actual bone 102. The conversion unit 24 records the three-dimensional position information of the target installation position of the magnetic sensor 301-2 in the storage device 3.

[0071] The fixture 210 and the fixture 220 are made by a three-dimensional printer (3D printer) before the operation. In addition, the conversion unit 24 can also determine the direction (target installation posture) of the cylindrical installation portion of the fixture 210 according to the direction of the fixture 210 installed in the target installation position in the skull model.

[0072] The storage device 3 stores in advance the information of the shape of the three-dimensional model of the skull model and the information of the shape of the three-dimensional model of the maxillary model. The data format of the three-dimensional model of the skull model and the maxillary model is, for example, DICOM (Digital Imaging and Communications in Medicine). Here, for example, the data format of the three-dimensional model of the dentition is STL (Stereolithography). The storage device 3 stores the information of the movement amount (movement parameter) and the information of the rotation amount (rotation parameter) according to the control signal sent from the planning device 2.

[0073] <Overview of Navigation of Sensor Installation Position During Surgery>

[0074] The detection device 5 generates a magnetic field region in a real space within a predetermined range including the patient's head and each magnetic sensor 301. The detection device 5 detects (tracks) the position and posture of each magnetic sensor 301 in real time based on the output (signal) of each magnetic sensor 301 in the generated magnetic field region.

[0075] The operator attaches the magnetic sensor 301 - 1 to the attachment portion of the jig 210 . The operator also attaches the magnetic sensor 301 - 2 to the attachment portion of the jig 220 .

[0076] The navigation device 6 takes the position of the magnetic sensor 301-2 inserted into the clamp 220 as the origin, and prompts (guides) the operator in real time with the specified first information for navigating the position and posture of the magnetic sensor 301-1, so that the operator moves and rotates the clamp 210 and the magnetic sensor 301-1 until the position and posture of the magnetic sensor 301-1 are consistent with the target installation position and target installation posture of the magnetic sensor 301-1 predetermined on the patient's bone 101.

[0077] There are many cases where the clamps are installed on the lateral edge of the piriform aperture and the mandible, but there are no obvious marks on the lateral edge of the piriform aperture and the mandible. Therefore, it has been difficult to visually set each clamp on the lateral edge of the piriform aperture and the mandible as planned before surgery. In an embodiment of the present invention, the position of the mounting portion 221 provided on the clamp 220 is set as the origin, and the clamp 220 can accurately install the magnetic sensor 301-2 at the position (origin) determined on the mandible. Thereby, the accurate installation position of the clamp 210 at the lateral edge of the piriform aperture can be prompted (guided) to the operator.

[0078] The first information may include, for example, an image of a three-dimensional model (skull model) of the skeleton 101 whose shape has been measured in advance, an image of a three-dimensional model (maxillary model) of the skeleton 102 whose shape has been measured in advance, an image of a three-dimensional coordinate axis representing the relative position and relative posture of each magnetic sensor 301 (each fixture), and an image of a three-dimensional coordinate axis representing the target installation position and the target installation posture. Figure 8 and Fig. 9 Describe the details of the first information.

[0079] By presenting such first information to the operator in real time, the navigation system 1 assists the operator in accurately installing the jig 210 (magnetic sensor 301 - 1 ) so that the relative posture of the magnetic sensor 301 - 1 becomes a target installation posture at a predetermined target installation position on the skeleton 101 .

[0080] <Details of navigation of the installation position of the sensor during surgery>

[0081] The clamp 210 is a clamp for fixing the magnetic sensor 301-1 to the bone 101. The clamp 210 is temporarily fixed to the bone 101 by the operator. The clamp 220 is a clamp for fixing the magnetic sensor 301-2 to the bone 102. The clamp 220 is temporarily fixed to the dentition of the bone 102 by the operator.

[0082] The magnetic sensor 301-1 is arranged near the bone 101 using the jig 210. The vicinity of the bone refers to, for example, a range of about 0.1 mm to about 10 mm from the bone. In an embodiment of the present invention, the magnetic sensor 301-1 is inserted into a hole of the mounting portion 211 provided in the jig 210. The magnetic sensor 301-1 is arranged near the bone 101, so that the bone 101 can be accurately aligned.

[0083] The magnetic sensor 301 is a sensor for detecting magnetism. The magnetic sensor 301 detects magnetism at the position of the sensor in the magnetic field generated by the magnetic field generating unit 51 at a predetermined period (e.g., 40 Hz) using a magnetic detection device such as a coil. The magnetic sensor 301 outputs an electrical signal corresponding to the detected magnetism to the acquiring unit 52.

[0084] The magnetic sensor 301-1 is temporarily mounted at a predetermined target mounting position on the surface of the bone 101 (skull) using the jig 210. That is, the magnetic sensor 301-1 is temporarily mounted at a predetermined target mounting position on the surface of the bone 101 by being inserted into the mounting portion of the jig 210 temporarily fixed to the bone 101. Therefore, the position and posture detected based on the output (signal) of the magnetic sensor 301-1 mounted on the bone 101 represent the position and posture of the bone 101.

[0085] The magnetic sensor 301-2 is temporarily mounted at a target mounting position predetermined on the surface of the bone 102 using the jig 220 engaged with the dentition of the bone 102. The magnetic sensor 301-2 is mounted near the bone 102 using the jig 220 by inserting the magnetic sensor 301-2 into a hole of the mounting portion 221 provided in the jig 220, just as the magnetic sensor 301-1 is inserted into a hole of the mounting portion 211 provided in the jig 210. That is, the magnetic sensor 301-2 is temporarily mounted at a target mounting position predetermined on the surface of the bone 102 by being inserted into the mounting portion of the jig 220 temporarily fixed to the dentition of the bone 102. Therefore, the position and posture detected based on the output of the magnetic sensor 301-2 mounted on the bone 102 represent the position and posture of the bone 102.

[0086] The magnetic field generating unit 51 generates a magnetic field region in an actual space within a specified range including the skeleton 101, the skeleton 102, and each magnetic sensor 301 (for example, an actual space within a range including the patient's head). The acquiring unit 52 acquires the output of the magnetic sensor 301 (an electrical signal corresponding to magnetism). The detecting unit 53 detects the position and posture of the magnetic sensor 301 at a specified period (for example, 40 Hz) based on the output of the magnetic sensor 301. The degree of freedom of the detected position is 3 degrees of freedom (X-axis, Y-axis, Z-axis). In addition, the degree of freedom of the detected posture (inclination) is 3 degrees of freedom (roll axis, pitch axis, yaw axis). The communication unit 54 sends information on the position and posture (a total of 6 degrees of freedom) of the magnetic sensor 301 to the communication unit 61 at a specified period (for example, 40 Hz).

[0087] The communication unit 61 obtains information on the shape of the three-dimensional model of the skeleton 101 and information on the shape of the three-dimensional model of the skeleton 102 from the storage device 3. The communication unit 61 obtains information on the target installation position of the magnetic sensor 301-1 (clamp 210) from the storage device 3. The communication unit 61 may also obtain information on the target installation posture of the magnetic sensor 301-1 (clamp 210) from the storage device 3. The communication unit 61 obtains information on the position and posture of each magnetic sensor 301 from the communication unit 54 at a predetermined period.

[0088] The storage unit 62 stores information on the target installation position of the magnetic sensor 301-1 (clamp 210). The storage unit 62 stores information on the target installation posture of the magnetic sensor 301-1 (clamp 210). The storage unit 62 (buffer memory) temporarily stores time series information on the position and posture of each magnetic sensor 301. The storage unit 62 temporarily stores time series information on the position and posture of the skeleton 101 and time series information on the position and posture of the skeleton 102. The storage unit 62 may also pre-store a computer program executed by the export unit 64 and the information generation unit 65.

[0089] The acquisition unit 63 acquires information on the shape of the skeleton 101 and information on the shape of the skeleton 102 from the storage device 3. The acquisition unit 63 acquires information on the target installation position and target installation posture of the magnetic sensor 301-1 from the communication unit 61 or the storage unit 62. Information on the position and posture of the magnetic sensor 301-1 (clamp 210) and information on the position and posture of the magnetic sensor 301-2 (clamp 220) are acquired from the communication unit 61 or the storage unit 62 at a predetermined period.

[0090] The deriving unit 64 derives the target installation position and the target installation posture predetermined on the surface of the bone 101 (skull) in real time, taking the position of the magnetic sensor 301-2 mounted on the fixture 220 engaged with the teeth as the origin, based on the information of the target installation position and the target installation posture specified by the planner. The deriving unit 64 derives the relative position and the relative posture of the magnetic sensor 301-1 (fixture 210) with respect to the target installation position and the target installation posture in real time based on the information of the position and posture of the magnetic sensor 301-1 obtained.

[0091] The information generation unit 65 generates navigation images at a predetermined frame rate (e.g., 40 fps) using a predetermined image processing engine (3D computer graphics rendering engine). The navigation images include, for example, images representing the appearance (shape) of bones generated during preoperative planning, predetermined text information, and images of 3D coordinate axes.

[0092] The information generating unit 65 generates an image representing the appearance of the skeleton 101 corresponding to the position and posture of the skeleton 101 (image of the skull model) and an image representing the appearance of the skeleton 102 corresponding to the relative position and relative posture of the skeleton 102 (image of the maxillary model).

[0093] When each magnetic sensor 301 (each clamp) is installed on each bone during surgery, the information generation unit 65 generates an image of a three-dimensional coordinate axis representing the current position and posture of each magnetic sensor 301 (each clamp). In addition, the information generation unit 65 generates an image of a three-dimensional coordinate axis representing the target installation position and target installation posture of the magnetic sensor 301-1.

[0094] The display unit 66 displays the navigation image generated by the information generating unit 65 at a predetermined frame rate (e.g., 40 fps). For example, the display unit 66 displays an image of three-dimensional coordinate axes indicating the current position and posture of the magnetic sensor 301-1 (clamp 210) and an image of three-dimensional coordinate axes indicating the target installation position and target installation posture of the magnetic sensor 301-1 (clamp 210).

[0095] The operator connects the clamp 220 in which the magnetic sensor 301-2 is inserted to the teeth of the patient's skeleton 102. In addition, the operator accurately installs the clamp 210 in which the magnetic sensor 301-1 is inserted to the target installation position predetermined on the patient's skeleton 101 using a screw (metal screw) or the like while confirming the navigation image. Here, the operator accurately installs the magnetic sensor 301-1 to the skeleton 101 while confirming the navigation image so that the relative posture of the magnetic sensor 301-1 with respect to the posture of the magnetic sensor 301-2 becomes the target installation posture.

[0096] <Overview of Navigation of Relative Movement and Rotation of Bones During Surgery>

[0097] The operator separates the bone 102 (maxilla) from the bone 101 (skull). Here, the operator may separate the bone 102 (maxilla) from the bone 101 (skull) after temporarily removing the clamp from the bone.

[0098] The detection device 5 generates a magnetic field region in a real space within a predetermined range including the patient's head and each magnetic sensor 301. The detection device 5 detects (tracks) the position and posture of each magnetic sensor 301 in real time based on the output (signal) of each magnetic sensor 301 in the generated magnetic field region.

[0099] The navigation device 6 prompts (guides) the operator in real time with the specified second information for navigating the movement and rotation of the bone 102 performed by the operator, so that the operator moves and rotates the bone 102 until the relative position and relative posture of the bone 102 relative to the position and posture of the bone 101 are consistent with the target relative position and target relative posture.

[0100] The prescribed second information includes, for example, an image of a three-dimensional model (skull model) of the skeleton 101 whose shape has been measured in advance, an image of a three-dimensional model (maxillary model) of the skeleton 102 whose shape has been measured in advance, an image of a three-dimensional coordinate axis representing the position and posture of the skeleton 101, an image of a three-dimensional coordinate axis representing the relative position and relative posture of the skeleton 102 relative to the position and posture of the skeleton 101, and an image of a three-dimensional coordinate axis representing the target relative position and target relative posture of the skeleton 102. Fig.11 and Fig.12 Describe the details of the second information.

[0101] By presenting such second information to the operator in real time, the navigation system 1 assists the operator in accurately moving and rotating (tilting) the bone 102 so that the position and posture of the bone 102 become the target relative position and target relative posture.

[0102] <Details of navigation of bone movement and rotation during surgery>

[0103] The communication unit 61 obtains information on the shape of the three-dimensional model (skull model) of the skeleton 101 and information on the shape of the three-dimensional model (maxilla model) of the skeleton 102 from the storage device 3. The communication unit 61 obtains information on a predetermined amount of movement and information on a predetermined amount of rotation from the storage device 3. The communication unit 61 obtains information on the position and posture of the skeleton 101 and information on the position and posture of the skeleton 102 from the communication unit 54 at a predetermined period.

[0104] The storage unit 62 stores information on a predetermined amount of movement and information on a predetermined amount of rotation. The storage unit 62 (buffer memory) temporarily stores time series information on the position and posture of the skeleton 101 and time series information on the position and posture of the skeleton 102. The storage unit 62 may also store in advance a computer program executed by the export unit 64 and the information generation unit 65.

[0105] The acquisition unit 63 acquires information on the shape of the three-dimensional model (skull model) of the skeleton 101 and information on the shape of the three-dimensional model (maxillary model) of the skeleton 102 from the storage device 3. The acquisition unit 63 acquires information on a predetermined amount of movement and information on a predetermined amount of rotation from the communication unit 61 or the storage unit 62. The acquisition unit 63 acquires information on the position and posture of the magnetic sensor 301-1 (clamp 210) and information on the position and posture of the magnetic sensor 301-2 (clamp 220) from the communication unit 61 or the storage unit 62 at a predetermined period.

[0106] When the magnetic sensor 301-1 (clamp 210) is mounted on the skeleton 101, the acquisition unit 63 acquires information on the position and posture of the magnetic sensor 301-1 from the communication unit 61 or the storage unit 62 at a predetermined period as information on the position and posture of the skeleton 101. Similarly, when the magnetic sensor 301-2 (clamp 220) is mounted on the skeleton 102, the acquisition unit 63 acquires information on the position and posture of the magnetic sensor 301-2 from the communication unit 61 or the storage unit 62 at a predetermined period as information on the position and posture of the skeleton 102.

[0107] The derivation unit 64 derives the relative position and relative posture of the magnetic sensor 301-2 relative to the position and posture of the magnetic sensor 301-1 in real time based on the information of the position and posture of the magnetic sensor 301-1 and the information of the position and posture of the magnetic sensor 301-2. In other words, the derivation unit 64 derives the relative position and relative posture of the skeleton 102 relative to the position and posture of the skeleton 101 in real time based on the information of the position and posture of the skeleton 101 and the information of the position and posture of the skeleton 102.

[0108] The derivation unit 64 derives the target relative position and target relative posture of the skeleton 102 relative to the position and posture of the skeleton 101 in real time based on the predetermined movement and rotation amounts of the initial values ​​of the relative position and relative posture of the skeleton 102 in the preoperative planning and the relative position and relative posture of the skeleton 102. Here, the position and posture in which the relative position and relative posture of the skeleton 102 are moved and rotated by the predetermined movement and rotation amounts are the target relative position and target relative posture of the skeleton 102.

[0109] The information generation unit 65 generates a navigation image at a predetermined frame rate using a predetermined image processing engine. The navigation image includes, for example, an image representing the appearance (shape) of bones generated in preoperative planning, predetermined text information, and an image of three-dimensional coordinate axes.

[0110] The information generation unit 65 generates an image representing the appearance of the skeleton 101 corresponding to the position and posture of the skeleton 101 (an image of the skull model) and an image representing the appearance of the skeleton 102 corresponding to the relative position and relative posture of the skeleton 102 (an image of the maxillary bone model). For example, when the skeleton 101 to which the magnetic sensor 301-1 is mounted is in a horizontal position, the information generation unit 65 generates an image representing the horizontal appearance of the skeleton 101 (an image of the skull model in a horizontal position). For example, when the skeleton 102 to which the magnetic sensor 301-2 is mounted moves, the information generation unit 65 causes the image representing the appearance of the skeleton 102 to move on the screen according to the movement of the skeleton 102.

[0111] The information generating unit 65 generates, for example, an image of three-dimensional coordinate axes representing the target relative position and target relative posture of the skeleton 102 based on the target relative position and target relative posture of the skeleton 102 relative to the position and posture of the skeleton 101. For example, when the skeleton 101 on which the magnetic sensor 301-1 is mounted is in a horizontal position, the target relative position and target relative posture of the skeleton 102 are also in a horizontal position, and therefore the information generating unit 65 generates an image of three-dimensional coordinate axes representing the target relative position and target relative posture of the skeleton 102 in a horizontal direction.

[0112] The information generation unit 65 generates, for example, an image of a three-dimensional coordinate axis representing the relative position and relative posture of the skeleton 102 based on the relative position and relative posture of the skeleton 102 relative to the position and posture of the skeleton 101. In addition, the information generation unit 65 may also generate an image of a line connecting the relative position of the skeleton 102 and the target relative position. For example, when the skeleton 102 to which the magnetic sensor 301-2 is attached moves, the information generation unit 65 causes the image of the three-dimensional coordinate axis representing the relative position and relative posture of the skeleton 102 to move on the screen according to the movement of the skeleton 102.

[0113] The display unit 66 displays the navigation image generated by the information generating unit 65 at a predetermined frame rate (eg, 40 fps).

[0114] Next, preoperative planning before surgery will be described in more detail.

[0115] Figure 2 1 is a diagram showing a skull model 111 and a maxillary bone model 112 in the first embodiment. The skull model 111 corresponds to the skeleton 101 in the real space. The maxillary bone model 112 corresponds to the skeleton 102 in the real space.

[0116] The information (DICOM data) of the shapes of the skull model 111 and the maxillary model 112 is obtained, for example, as a result of a CT scan of the patient's head before surgery. In addition, data (STL data) obtained as a result of an optical digital scan of the patient's dentition before surgery can also be used as dentition data of the maxillary model 112.

[0117] Figure 3 1 is a diagram showing an example of the position and posture of the maxillary bone model 112 before and after the movement in the first embodiment. In preoperative planning, the movement processing unit 21 moves the maxillary bone model 112 on the screen from the initial value of the position of the maxillary bone model 112 according to the mouse operation performed by the planner (doctor), etc. The rotation processing unit 22 rotates the maxillary bone model 112 on the screen from the initial value of the posture of the maxillary bone model 112 according to the mouse operation performed by the planner, etc. Figure 3 The left-hand figure shows the position (initial value) and posture (initial value) of the skull model 111 before movement and rotation. Figure 3 The figure on the right side shown shows the position and posture of the skull model 111 after the movement and rotation.

[0118] Figure 4 : is a diagram showing an example of determining movement parameters and rotation parameters (rotation matrix) in the first embodiment. In preoperative planning, the planner determines the relative position and relative posture of the bone 102 after surgery by moving and rotating the maxillary bone model 112 on the screen from the initial values ​​of the position and posture of the maxillary bone model 112. At least one of the movement processing unit 21 and the rotation processing unit 22 uses a prescribed algorithm for alignment to determine at least one of the movement amount and the rotation amount. The prescribed algorithm for alignment is, for example, an ICP (Iterative Closest Point) algorithm. The movement processing unit 21 records the information of the determined movement amount (movement parameter) in the storage device 3. The rotation processing unit 22 records the information of the determined rotation amount (rotation parameter) in the storage device 3.

[0119] Next, the designation of the attachment position of the magnetic sensor (jig) before surgery will be described.

[0120] Figure 5 2 is a diagram showing an example of specifying the installation position (target installation position) of the magnetic sensor 301 in the first embodiment. Figure 5 , the left side of the figure shows the installation position of the magnetic sensor 301 before the maxillary bone model 112 is separated from the skull model 111 on the screen. Figure 5 On the right side of the screen, the installation position of the magnetic sensor 301 is shown when the maxillary bone model 112 is separated from the skull model 111 and then the maxillary bone model 112 and the skull model 111 are reconnected.

[0121] exist Figure 5 middle, Figure 1 The illustrated fixture 220 is clamped between the teeth of the maxillary model 112 and the teeth of the mandibular model 113, and is engaged with both. The installation position 10 represents the installation position of the magnetic sensor 301-2 (fixture 220) installed on the actual skeleton 102. The installation position 11 represents the target installation position of the magnetic sensor 301-1 installed on the actual skeleton 101. The installation position 11 is represented with the installation position 10 as the origin.

[0122] In preoperative planning, the planner specifies the installation position 10 as the installation position (origin) of the magnetic sensor 301-2 on the bone 102 by marking a mark on the dentition surface of the maxillary bone model 112, for example, by operating the mouse. The installation position (origin) of the magnetic sensor 301-2 is the position of the installation portion of the magnetic sensor 301-2 in the fixture 220. In addition, the planner determines the installation position 11 as the installation position (target installation position) of the magnetic sensor 301-1 on the bone 101, for example, by marking a mark on the surface of the skull model 111 (the rim of the pyriform aperture of the skull).

[0123] like Figure 5 As shown on the left side of , the planner specifies, for example, on the screen the installation position 10 and the installation position 11 in a state where the maxillary bone model 112 is not separated from the skull model 111.

[0124] like Figure 5 As shown on the right side of , the planner can also designate, for example, the installation position 10 and the installation position 11 in the state where the maxillary model 112 is separated from the skull model 111 and then the maxillary model 112 and the skull model 111 are reconnected on the screen. Here, the conversion unit 24 can also specify the state where the maxillary model 112 and the skull model 111 are reconnected ( Figure 5 The installation position 11 under the right side of the upper jaw model 112 is corrected to a state where the maxillary bone model 112 is not separated from the skull model 111 ( Figure 5 Thus, even if the operator specifies the installation position 11 in the state where the maxillary bone model 112 and the skull model 111 are rejoined in the preoperative planning, the operator can accurately install the magnetic sensor 301-1 (clamp 210) at the installation position 11 before separating the bone 102 from the bone 101.

[0125] Next, the preparation of the jig (jig shaping) before surgery will be described.

[0126] Figure 6 1 is a diagram showing an example of a fixture engaged with a skull (skeleton 101) in the first embodiment. The fixture 210 is manufactured using a CAD / CAM (computer-aided design / computer-aided manufacturing) method. That is, the design data of the shape of the fixture 210 is designed based on the DICOM data of the skull model 111. In addition, the fixture 210 is manufactured based on the design data of the shape of the fixture 210 (e.g., STL data), for example, by a three-dimensional printer (3D printer).

[0127] The material of the jig 210 is a non-magnetic body, such as resin. The jig 210 has one or more mounting parts 211 for mounting the magnetic sensor 301-1 and a joining surface having a shape corresponding to the surface shape of the bone 101 (the rim of the pyriform aperture of the skull) to be joined.

[0128] The shape of the mounting portion 211 is, for example, cylindrical. The front end portion (magnetic detection device) of the magnetic sensor 301-1 can be inserted into the mounting portion 211. By inserting the magnetic sensor 301-1 into the mounting portion 211, the magnetic sensor 301-1 is set near the bone 101, so that the position of the magnetic sensor 301-1 accurately represents the position of the bone 101. As a result, the relative position of the bone 102 can be matched with the target relative position with high accuracy.

[0129] When the jig 210 with the magnetic sensor 301-1 inserted therein is mounted on the bone 101, the orientation of each mounting portion is designed based on the target mounting posture of the jig 210 so that the orientation of the magnetic sensor 301-1 inserted into the mounting portion 211 (relative to the first orientation predetermined for the jig 210) is the same as the orientation of the magnetic sensor 301-2 inserted into the mounting portion 221 of the jig 220 (relative to the second orientation predetermined for the jig 220). In addition, the shape of the joint surface of the jig 210 is designed to match the surface shape of the bone 101 at the target mounting position of the jig 210.

[0130] Figure 7: This is a diagram showing an example of a fixture 220 (tooth brace) (dentition splint) engaged with the dentition of the maxillary bone (skeleton 102) in the first embodiment. In orthognathic surgery, the patient's dentition is corrected before the surgery so that the patient's teeth are optimally arranged after the surgery. In order to accurately engage the fixture 220 with the corrected dentition, the fixture 220 is a CAD / CAM splint (computer-aided design / computer-aided manufacturing sprint) formed with a joining surface having a shape corresponding to the surface shape of the dentition. That is, the design data of the shape of the fixture 220 is designed based on the STL data of the maxillary bone model 112. In addition, the fixture 220 is manufactured based on the design data of the shape of the fixture 220, for example, by a three-dimensional printer. The fixture 220 engages with the patient's dentition and is therefore accurately fixed to the patient's maxillary bone (skeleton 102).

[0131] The material of the fixture 220 is a non-magnetic body, such as resin. The fixture 220 has one or more mounting portions 221 for mounting the magnetic sensor 301-2 and a joint surface 222 whose shape corresponds to the surface shape of the bone 102 (dentition of the maxillary bone). The shape of the mounting portion 221 is, for example, cylindrical. The front end portion (magnetic detection device) of the magnetic sensor 301-2 can be inserted into the mounting portion 221. By inserting the magnetic sensor 301-2 into the mounting portion 221, the magnetic sensor 301-2 is arranged near the bone 102, so that the position of the magnetic sensor 301-2 represents the position of the bone 102 with high accuracy.

[0132] As an example, the position of the mounting portion 221-1 among the mounting portion 221-1, the mounting portion 221-2, and the mounting portion 221-3 is a position passing through the midline of the patient or near it when the engagement surface 222 engages with the dentition of the bone 102. The magnetic sensor 301-2 can be mounted on any one of the mounting portion 221-1, the mounting portion 221-2, and the mounting portion 221-3.

[0133] The dental brace-type fixture 220 is coupled to the bone 102 and the mandible (not shown), so that the bone 102 and the mandible (not shown) become one. That is, the position of the patient's mandible follows the position of the bone 102 (maxilla) moved by the operator. The maxilla and mandible do not deviate during the movement, so navigation can be performed more easily.

[0134] Next, the navigation of the installation position of the magnetic sensor 301 (jig) during surgery will be described in more detail.

[0135] Figure 81 is a diagram showing an example of a navigation image indicating an installation position in the first embodiment. During surgery, the display unit 66 displays a navigation image indicating the relative position and relative posture of the magnetic sensor 301-1 with respect to the target installation position and target installation posture of the magnetic sensor 301-1 (clamp 210) in real time at a predetermined frame rate. Figure 8 An example of a navigation image at the first moment in surgery is shown.

[0136] Figure 8 The illustrated navigation images include an image of the skull model 111, an image of the maxillary model 112, a fixture image 213, a fixture image 223, a coordinate axis image 14 configured at the installation position 10, a coordinate axis image 15 configured at the installation position 11, a coordinate axis image 16, a connection image 17 and a display area 18.

[0137] The jig image 213 is an image of a three-dimensional model of the jig 210. The jig image 223 is an image of a three-dimensional model of the jig 220. The mounting position 10 is the mounting position (origin) of the magnetic sensor 301-2. The mounting position 11 is the target mounting position of the magnetic sensor 301-1 (jig 210).

[0138] The coordinate axis image 14 is represented by three mutually orthogonal line segments (X axis, Y axis, and Z axis). The origin of the coordinate axis image 14 represents the position (mounting position 10) of the magnetic sensor 301-2 mounted on the fixture 220. The posture of the coordinate axis image 14 represents the posture of the magnetic sensor 301-2 mounted on the mounting portion 221 of the fixture 220.

[0139] The coordinate axis image 15 is represented by three mutually orthogonal line segments (X axis, Y axis, and Z axis). The origin of the coordinate axis image 15 represents the target mounting position (mounting position 11) of the magnetic sensor 301-1. The posture of the coordinate axis image 15 represents the target mounting posture of the magnetic sensor 301-1.

[0140] The coordinate axis image 16 is represented by three mutually orthogonal line segments (X axis, Y axis and Z axis). The origin of the coordinate axis image 16 represents the relative position of the magnetic sensor 301-1 mounted on the fixture 210 relative to the mounting position 11 (target mounting position). The posture of the coordinate axis image 16 represents the posture of the magnetic sensor 301-1 mounted on the mounting portion 211 of the fixture 210.

[0141] The connection line image 17 is a line connecting the target mounting position and the relative position of the magnetic sensor 301-1. The length of the connection line image 17 represents the difference (distance) between the relative position of the target mounting position and the magnetic sensor 301-1.

[0142] The color of the X axis of the coordinate axis image 14, the color of the X axis of the coordinate axis image 15, and the color of the X axis of the coordinate axis image 16 are the same color (for example, red). The color of the Y axis of the coordinate axis image 14, the color of the Y axis of the coordinate axis image 15, and the color of the Y axis of the coordinate axis image 16 are the same color (for example, blue). The color of the Z axis of the coordinate axis image 14, the color of the Z axis of the coordinate axis image 15, and the color of the Z axis of the coordinate axis image 16 are the same color (for example, green). In addition, the color of the line image 17 connecting the origin (target installation position) of the coordinate axis image 15 and the origin (the relative position of the magnetic sensor 301-1 at the current moment) of the coordinate axis image 16 is, for example, purple.

[0143] The display area 18 is an area for displaying at least one of numerical information and text information. The numerical information displayed in the display area 18 indicates the difference between the target installation position and the relative position of the magnetic sensor 301-1. In addition, the text information displayed in the display area 18 indicates the moving direction to reduce the difference between the relative position of the target installation position and the magnetic sensor 301-1.

[0144] The operator attaches the magnetic sensor 301-1 to the attachment portion 211 of the clamp 210. In addition, the operator attaches the magnetic sensor 301-2 to the attachment portion 221-1 of the clamp 220. The operator engages the clamp 220 with the bone 102. While checking the navigation image displayed in real time on the display unit 66, the operator moves and rotates the actual clamp 210 so that the coordinate axis image 15 and the coordinate axis image 16 overlap on the screen of the display unit 66.

[0145] Fig. 9 It is a diagram showing an example of a navigation image indicating an installation position in the first embodiment. Fig. 9 An example of a navigation image at a second time later than the first time is shown. At the second time, as a result of the operator moving and rotating the clamp 210, the coordinate axis image 15 and the coordinate axis image 16 are roughly overlapped. In this case, the relative position of the clamp 210 is roughly consistent with the target installation position. In addition, the relative posture of the clamp 210 is roughly consistent with the target installation posture.

[0146] Fig.10 FIG. 1 is a diagram showing an example of mounting the magnetic sensor 301 in the first embodiment. Fig.10 In the embodiment, the clamp 210 is temporarily fixed to the bone 101 using a small screw or the like while the joint surface 212 of the clamp 210 is engaged with the bone 101 (rim of the pyriform aperture of the skull). In addition, the clamp 220 is temporarily fixed to the bone 102 while the joint surface 222 of the clamp 220 is engaged with the dentition of the bone 102.

[0147] Here, the orientation (prescribed orientation) of the mounting portion 211 in the jig 210 in the state of being engaged with the skeleton 101 is the same as the orientation (prescribed orientation) of each mounting portion 221 in the jig 220 in the state of being engaged with the skeleton 102. Thus, the calibration of the orientation of each magnetic sensor 301 (the initial value of the posture of each skeleton) can be omitted.

[0148] Next, navigation of the position of bones during surgery will be described in more detail.

[0149] Fig.11 1 is a diagram showing an example of a navigation image showing the relative position of bones in the first embodiment. The display unit 66 displays the navigation image generated by the information generation unit 65 at a predetermined frame rate (e.g., 40 fps). In the navigation image, the shape of the bone 101 is represented by an image of a cranial model 111. In addition, the shape of the bone 102 is represented by an image of a maxillary model 112.

[0150] Fig.11 The illustrated navigation image includes an image of the cranial model 111, an image of the maxillary model 112, a display area 401, a coordinate axis image 402, a coordinate axis image 403, and a connection image 404. The display area 401 is an area that displays at least one of numerical information and text information. The numerical information displayed in the display area 401 indicates the difference between the target relative position of the skeleton 102 and the relative position of the skeleton 102. In addition, the text information displayed in the display area 401 indicates the moving direction that reduces the difference between the target relative position of the skeleton 102 and the relative position of the skeleton 102.

[0151] The coordinate axis image 402 is represented by three mutually orthogonal line segments (X axis, Y axis, and Z axis). The origin of the coordinate axis image 402 represents the target relative position of the skeleton 102. The posture of the coordinate axis image 402 represents the target relative posture of the skeleton 102.

[0152] The coordinate axis image 403 is represented by three mutually orthogonal line segments (X axis, Y axis, and Z axis). The origin of the coordinate axis image 403 represents the relative position of the skeleton 102 relative to the target relative position of the skeleton 102. The posture of the coordinate axis image 403 represents the relative posture of the skeleton 102.

[0153] The numerical information indicating the difference is, for example, a numerical value indicating the distance in millimeters. The text information indicating the moving direction is, for example, a character string such as "Left" and "Down". The operator can also move the skeleton 102 in the moving direction indicated by the text information while confirming the navigation image to reduce the value of the numerical information. In addition, the distance (proximity) from the target relative position to the relative position and the text information "Proximity" can also be displayed. In addition, the numerical information indicating the difference can also be the difference between the posture of the coordinate axis image 402 and the posture of the coordinate axis image 403 (the consistency rate of each axis). The consistency between the posture of the coordinate axis image 402 and the posture of the coordinate axis image 403 indicates that the target relative posture of the skeleton 102 is consistent with the relative posture of the skeleton 102.

[0154] The color of the X-axis of the coordinate axis image 402 is the same color as the color of the X-axis of the coordinate axis image 403 (for example, red). The color of the Y-axis of the coordinate axis image 402 is the same color as the color of the Y-axis of the coordinate axis image 403 (for example, blue). The color of the Z-axis of the coordinate axis image 402 is the same color as the color of the Z-axis of the coordinate axis image 403 (for example, green). In addition, the color of the line image 404 connecting the origin of the coordinate axis image 402 (the target relative position) and the origin of the coordinate axis image 403 (the relative position of the bone 102 at the current moment) is, for example, purple. The length of the line image 404 represents the difference (distance) between the target relative position and the relative position of the bone 102 (maxillary bone model 112).

[0155] Fig.12 1 is a diagram showing an example of a navigation image showing the position of a bone, etc. in the first embodiment. During surgery, the operator moves and rotates the bone 102 so that the coordinate axis image 402 and the coordinate axis image 403 overlap while checking the navigation image displayed in real time on the display unit 66 at a predetermined frame rate.

[0156] Fig.12 The left figure (a part of the navigation image) shown shows the position and posture of the skeleton 101 (skull model 111) and the position and posture of the skeleton 102 (maxillary bone model 112) at the third moment during the operation. Fig.12 The right side diagram (part of the navigation image) shows the position and posture of the skeleton 101 (skull model 111) and the position and posture of the skeleton 102 (maxilla model 112) at a fourth time later than the third time. Fig.12In the right figure shown, as a result of the operator moving and rotating the bone 102, the coordinate axis image 402 roughly overlaps the coordinate axis image 403. In this case, the relative position and relative posture of the bone 102 relative to the position and posture of the bone 101 are close to the target relative position and target relative posture predetermined in the preoperative planning.

[0157] The orientation of the mounting portion 211 of the clamp 210 mounted at the target mounting position of the bone 101 is the same as the orientation of the mounting portion 221 of the clamp 220 mounted on the bone 102 rejoined with the bone 101. In this case, the posture of the magnetic sensor 301-2 inserted into the mounting portion 221 becomes the same posture (inclination) as the posture of the magnetic sensor 301-1 inserted into the mounting portion 211. Thus, the relative positional relationship between the coordinate axis image 402 and the coordinate axis image 403 is displayed in an intuitive and easy-to-understand manner, so that navigation surgery becomes extremely easy.

[0158] In addition, since the coordinate axis image 402 and the coordinate axis image 403 are respectively represented by three-dimensional coordinate axes, the operator can intuitively determine whether the relative position and relative posture of the bone 102 are accurately consistent with the target relative position and target relative posture by confirming the consistency of the coordinate axis image 402 and the coordinate axis image 403 in the navigation image. In addition, the patient can obtain a good occlusion and a beautiful appearance.

[0159] Hereinafter, the relative position of the first sensor relative to the target installation position of the first sensor (magnetic sensor 301-1) is referred to as the “first relative position”. Hereinafter, the relative posture of the first sensor relative to the target installation posture of the first sensor (magnetic sensor 301-1) is referred to as the “first relative posture”.

[0160] Next, an example of the operation of the navigation device 6 when the magnetic sensor is attached to the bone during surgery will be described.

[0161] Fig.13 1 is a flowchart showing a first operation example (operation example when a magnetic sensor is mounted on a skeleton) of the navigation device 6 in the first embodiment. The acquisition unit 63 acquires information on a target installation position and a target installation posture of the magnetic sensor 301-1 relative to the position and posture of the magnetic sensor 301-2 from the planning device 2 or the storage device 3 (step S101). The acquisition unit 63 acquires information on the position and posture of the magnetic sensor 301-1 detected based on the signal of the magnetic sensor 301-1 from the detection device 5 (step S102).

[0162] The derivation unit 64 derives the first relative position and the first relative posture of the magnetic sensor 301 - 1 based on the target mounting position and the target mounting posture of the magnetic sensor 301 - 1 and the position and the posture of the magnetic sensor 301 - 1 (step S103 ).

[0163] The information generation unit 65 generates an image of a three-dimensional coordinate axis representing the target installation position and the target installation posture of the magnetic sensor 301-1 (coordinate axis image 15). The information generation unit 65 generates an image of a three-dimensional coordinate axis representing the first relative position and the first relative posture of the magnetic sensor 301-1 (coordinate axis image 16). The information generation unit 65 may also generate an image of the fixture image 213, an image of the skull model 111, and an image of the maxillary model 112 (step S104). The display unit 66 displays the coordinate axis image 15 and the coordinate axis image 16. The display unit 66 may also display the fixture image 213, an image of the skull model 111, and an image of the maxillary model 112 (step S105).

[0164] The information generation unit 65 determines whether to end the navigation operation. For example, when the operation is completed, the information generation unit 65 determines that the navigation operation is ended (step S106). If it is determined that the navigation operation is to be continued (step S106: No), the information generation unit 65 returns the process to step S103. If it is determined that the navigation operation is to be ended (step S106: Yes), the information generation unit 65 ends the navigation operation.

[0165] Next, an example of the operation of the navigation device 6 when the bones relatively move and rotate during surgery will be described.

[0166] Fig.14 2 is a flowchart showing a second operation example (operation example when the skeleton moves and rotates relative to each other) of the navigation device 6 in the first embodiment. The acquisition unit 63 acquires information on the shape of the skeleton 101 (first skeleton) and the shape of the skeleton 102 (second skeleton) from the communication unit 61 or the storage unit 62 (step S201). The acquisition unit 63 acquires information on the predetermined amount of movement and rotation relative to the skeleton 102 from the communication unit 61 or the storage unit 62 (step S202).

[0167] During the operation, after the magnetic sensor 301 is mounted on the bone, the communication unit 61 and the storage unit 62 obtain information on the position and posture of the bone 101 from the communication unit 54 at a predetermined cycle. The acquisition unit 63 obtains information on the position and posture of the bone 101 from the communication unit 61 or the storage unit 62 at a predetermined cycle (step S203). The communication unit 61 obtains information on the position and posture of the bone 102 from the communication unit 54 at a predetermined cycle. The acquisition unit 63 obtains information on the position and posture of the bone 102 from the communication unit 61 or the storage unit 62 at a predetermined cycle (step S204).

[0168] The derivation unit 64 derives the relative position and relative posture of the skeleton 102 relative to the position and posture of the skeleton 101 based on the information of the position and posture of the skeleton 101 and the information of the position and posture of the skeleton 102 (step S205). The derivation unit 64 derives the target relative position and target relative posture of the skeleton 102 relative to the position and posture of the skeleton 101 based on the predetermined movement amount and rotation amount relative to the initial value of the relative position and relative posture of the skeleton 102 and the relative position and relative posture of the skeleton 102 (step S206).

[0169] The information generating unit 65 generates prescribed information including a coordinate axis image 402 (an image of a three-dimensional coordinate axis) indicating the target relative position and target relative posture of the skeleton 102 relative to the skeleton 101, based on the target relative position and target relative posture of the skeleton 102. The display unit 66 displays in real time an image of the skull model 111 indicating the appearance of the skeleton 101 corresponding to the position and posture of the skeleton 101 and the prescribed information of the coordinate axis image 402 (step S207).

[0170] The information generating unit 65 generates prescribed information including a coordinate axis image 403 (an image of a three-dimensional coordinate axis) indicating the relative position and relative posture of the skeleton 102 based on the relative position and relative posture of the skeleton 102 relative to the skeleton 101. The display unit 66 displays in real time an image of the maxillary bone model 112 indicating the appearance of the skeleton 102 corresponding to the relative position and relative posture of the skeleton 102 and the prescribed information of the coordinate axis image 403 (step S208).

[0171] The information generation unit 65 determines whether to end the navigation operation. For example, when the operation is completed, the information generation unit 65 determines that the navigation operation is to be ended (step S209). If it is determined that the navigation operation is to be continued (step S209: No), the information generation unit 65 returns the process to step S203. If it is determined that the navigation operation is to be ended (step S209: Yes), the information generation unit 65 ends the navigation operation.

[0172] As described above, the detection unit 53 detects the position and posture of the magnetic sensor 301-1 based on the signal of the magnetic sensor 301-1 (first sensor), and the magnetic sensor 301-1 is inserted into the mounting portion 211 in a first orientation predetermined relative to the clamp 210 having the engaging surface 212, and the engaging surface 212 has a surface with a shape corresponding to the surface of the bone 101 (for example, the skull). In addition, the detection unit 53 detects the position and posture of the magnetic sensor 301-2 based on the signal of the magnetic sensor 301-2 (second sensor), and the magnetic sensor 301-2 is inserted into the mounting portion 221 in a second orientation predetermined relative to the clamp 220 having the engaging surface 222, and the engaging surface 222 has a surface with a shape corresponding to the surface of the bone 102 (for example, the maxilla).

[0173] The acquisition unit 63 acquires information on the position and posture of the magnetic sensor 301-1 detected based on the signal of the magnetic sensor 301-1 from the detection device 5. The acquisition unit 63 acquires information on the target installation position and target installation posture of the magnetic sensor 301-1 relative to the position and posture of the magnetic sensor 301-2 from the planning device 2 or the storage device 3.

[0174] The derivation unit 64 derives the first relative position and the first relative posture based on the target installation position and the target installation posture and the position and posture of the magnetic sensor 301-1. The information generation unit 65 generates an image of the three-dimensional coordinate axis (coordinate axis image 15) representing the target installation position and the target installation posture of the magnetic sensor 301-1. The information generation unit 65 generates an image of the three-dimensional coordinate axis (coordinate axis image 16) representing the first relative position and the first relative posture of the magnetic sensor 301-1. Figure 8 and Fig. 9 As illustrated, the display unit 66 displays the coordinate axis image 15 and the coordinate axis image 16 .

[0175] In this way, the operator can accurately install the magnetic sensor 301-1 in the target installation posture at the target installation position in the actual bone 101 while observing the coordinate axis image 15 and the coordinate axis image 16 indicating the target installation position and the target installation posture of the magnetic sensor 301-1 in the skull model 111. This can assist the operator in accurately moving and rotating the bone 102 so that the relative position and the relative posture of the bone 102 become the target relative position and the target relative posture.

[0176] The information generating unit 65 may also generate numerical information indicating the difference between the target installation position and the first relative position. Figure 8 and Fig. 9 As shown in the example, the display unit 66 may also display numerical information. The information generating unit 65 may also generate text information indicating the moving direction for reducing the difference between the target installation position and the first relative position. Figure 8 and Fig. 9 As shown, the display unit 66 may also display text information. The information generating unit 65 may also generate an image of a line connecting the target installation position and the first relative position. Figure 8 and Fig. 9 As illustrated, the display unit 66 may also display the connection image 17 .

[0177] Hereinafter, the relative position of the second skeleton (skeleton 102) with respect to the position of the first skeleton (skeleton 101) is referred to as a “second relative position.” Hereinafter, the relative posture of the second skeleton with respect to the posture of the first skeleton is referred to as a “second relative posture.”

[0178] The acquisition unit 63 acquires information about the position and posture of the bone 101 detected based on the signal of the magnetic sensor 301-1 installed on the bone 101 (e.g., the skull) from the detection device 5. The acquisition unit 63 acquires information about the position and posture of the bone 102 detected based on the signal of the magnetic sensor 301-2 installed on the bone 102 (e.g., the maxilla) from the detection device 5.

[0179] The derivation unit 64 derives a second relative position and a second relative posture of the skeleton 102 relative to the position of the skeleton 101 based on the information on the position and posture of the skeleton 101 and the information on the position and posture of the skeleton 102. The derivation unit 64 derives a target relative position and a target relative posture of the skeleton 102 relative to the position and posture of the skeleton 101 based on a predetermined amount of movement relative to an initial value of the second relative position and a predetermined amount of rotation relative to an initial value of the second relative posture.

[0180] The information generation unit 65 generates an image of a three-dimensional coordinate axis representing the target relative position and the target relative posture (coordinate axis image 402). The information generation unit 65 generates an image of a three-dimensional coordinate axis representing the second relative position and the second relative posture (coordinate axis image 403). Fig.11 and Fig.12 As illustrated, the display unit 66 displays a coordinate axis image 402 and a coordinate axis image 403 .

[0181] Thus, the movement status and rotation status of the skeleton 102 are shown to the operator, so that the operator can be assisted in accurately moving and rotating the skeleton 102 to achieve a predetermined target relative position and target relative posture.

[0182] (Second Embodiment)

[0183] In the second embodiment, a magnetic sensor (clamp) is also attached to the proximal mandibular fracture fragment separated from the mandibular bone, which is different from the first embodiment. In the second embodiment, the differences from the first embodiment will be mainly described.

[0184] <Before surgery>

[0185] Fig.15 1 is a diagram showing a first example of specifying the installation position of each magnetic sensor 301 in the second embodiment. The installation position of the magnetic sensor 301 before the maxillary model 112 is separated from the cranial model 111 is shown on the screen of the display unit 23. The mandibular model 113 is a three-dimensional model of the mandibular bone of the patient.

[0186] exist Fig.15 In preoperative planning, Figure 1The illustrated fixture 220 is clamped between the dentition of the maxillary model 112 and the dentition of the mandibular model 113, and is engaged with both. The installation position 10 represents the installation position of the magnetic sensor 301-2 (fixture 220) installed on the actual bone 102. The installation position 11 represents the target installation position of the magnetic sensor 301-1 installed on the actual bone 101. The installation position 12 and the installation position 13 represent the target installation positions of each magnetic sensor 301 installed on the actual mandible. With the installation position 10 as the origin, the installation position 11, the installation position 12, and the installation position 13 are represented.

[0187] <During surgery>

[0188] Fig.16 This is a diagram showing an example of cutting of the bone 103 (mandibular bone) in the second embodiment. During the operation, the operator temporarily removes each magnetic sensor 301 from each bone. The operator separates the bone 102 from the bone 101 and cuts the bone 103.

[0189] Fig.17 This is a diagram showing an example of the attachment position of each magnetic sensor 301 after the bone 103 is cut in the second embodiment. Fig.17 The installation position of the magnetic sensor 301 is shown in a state where the bone 102 is separated from the bone 101 and the bone 102 and the bone 101 are rejoined.

[0190] exist Fig.17 In the figure, the bone 103 (mandible) is cut into the bone 103-1, the bone 103-2 (proximal mandibular fracture fragment) and the bone 103-3 (proximal mandibular fracture fragment). In the maxillary model 112 and the mandibular model 113-1, the installation position 10 of the first magnetic sensor 301-1 is determined by the planner. In the skull model 111, the installation position 11 of the second magnetic sensor 301-2 is determined by the planner. In the mandibular model 113-2, the installation position 12 of the third magnetic sensor 301-3 is determined by the planner. In the mandibular model 113-3, the installation position 13 of the fourth magnetic sensor 301-4 is determined by the planner. With the installation position 10 as the origin, the installation position 11, the installation position 12 and the installation position 13 are represented.

[0191] Therefore, for example, for the proximal mandibular fracture fragment of the bone 103, it is also possible to assist the surgeon to accurately move and rotate the bone 103 so that the relative position and relative posture of the bone 103 become the target relative position and target relative posture.

[0192] The second embodiment is suitable for surgery to align multiple bones (for example, surgery to reconstruct artificial bones for patients who have lost bones due to osteonecrosis of the jaw caused by cancer, etc.).

[0193] As mentioned above, although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to the embodiment and includes designs and the like within the scope that does not depart from the gist of the present invention.

[0194] For example, the number of sensors is not limited to a specific number. For example, by performing navigation using three or more sensors, the operator can align the relative position and relative posture of the bones with higher accuracy.

[0195] In addition, the navigation surgery in each embodiment is not limited to surgery in a specific field as long as it is a surgery that requires accurate matching of the relative positions and relative postures of each bone. For example, the navigation surgery can be a navigation surgery in orthognathic surgery between the maxilla and the mandible. Here, a jig (braces) for the maxilla and a jig (braces) for the mandible can also be made separately. Sensors can also be installed on each jig.

[0196] Industrial Applicability

[0197] The present invention can be applied to a surgery assisting system.

[0198] Description of Reference Numerals

[0199] 1: Navigation system

[0200] 2: Planning device

[0201] 3: Storage device

[0202] 4: Communication lines

[0203] 5: Detection device

[0204] 6: Navigation device

[0205] 10: Installation location

[0206] 11: Installation location

[0207] 12: Installation location

[0208] 13: Installation location

[0209] 14: Coordinate axis image

[0210] 15: Coordinate axis image

[0211] 16: Coordinate axis image

[0212] 17: Connecting images

[0213] 18: Display area

[0214] 21: Mobile Processing Department

[0215] 22: Rotation processing unit

[0216] 23: Display unit

[0217] 51: Magnetic field generation unit

[0218] 52: Get Department

[0219] 53: Inspection Department

[0220] 54: Ministry of Communications

[0221] 61: Ministry of Communications

[0222] 62: Storage

[0223] 63: Acquisition Department

[0224] 64: Export

[0225] 65: Information Generation Department

[0226] 66: Display unit

[0227] 101: Bones

[0228] 102: Skeleton

[0229] 103: Skeleton

[0230] 111: Skull Model

[0231] 112: Maxillary model

[0232] 113: Mandibular model

[0233] 210: Fixture

[0234] 211: Installation Department

[0235] 212: Joint surface

[0236] 213: Fixture Image

[0237] 220: Fixture

[0238] 221: Installation Department

[0239] 222: Joint surface

[0240] 223: Fixture Image

[0241] 301: Magnetic sensor

[0242] 401: Display area

[0243] 402: Axis Image

[0244] 403: Axis Image

[0245] 404: Connection image.

Claims

1. A navigation system comprising: an acquisition unit that acquires information on the position and posture of the first sensor detected based on a signal of the first sensor and information on a target installation position and a target installation posture of the first sensor relative to the position and posture of the second sensor detected based on a signal of the second sensor, wherein The first sensor is inserted into the mounting portion of the first fixture in a first orientation predetermined relative to the first fixture, the first fixture having a surface having a shape corresponding to the surface of the first bone, and the second sensor is inserted into the mounting portion of the second fixture in a second orientation predetermined relative to the second fixture, the second fixture having a surface having a shape corresponding to the surface of the second bone; a deriving unit configured to derive a first relative position and a first relative posture of the first sensor relative to the target installation position and the target installation posture based on the target installation position and the target installation posture and the position and posture of the first sensor; an information generating unit configured to generate an image of three-dimensional coordinate axes representing the target installation position and the target installation posture and an image of three-dimensional coordinate axes representing the first relative position and the first relative posture; as well as A display unit displays an image of three-dimensional coordinate axes indicating the target installation position and the target installation posture and an image of three-dimensional coordinate axes indicating the first relative position and the first relative posture.

2. The navigation system according to claim 1, wherein: The second fixture is a dentition splint.

3. The navigation system according to claim 1, wherein: The information generating unit generates numerical information indicating a difference between the target mounting position and the first relative position. The display unit further displays the numerical information.

4. The navigation system according to claim 1, wherein: The information generating unit generates text information indicating a moving direction for reducing a difference between the target mounting position and the first relative position. The display unit further displays the text information.

5. The navigation system according to claim 1, wherein: The information generating unit generates an image of a line connecting the target mounting position and the first relative position, The display unit further displays an image of the connection line.

6. The navigation system according to claim 1, wherein: The sensor is a magnetic sensor.

7. The navigation system according to claim 1, wherein: The first bone is a skull. The second bone is the maxilla.

8. The navigation system according to claim 1, wherein: The acquisition unit acquires information on the position and posture of the first bone detected based on a signal of the first sensor installed on the first bone and information on the position and posture of the second bone detected based on a signal of the second sensor installed on the second bone, The derivation unit derives a second relative position and a second relative posture of the second bone relative to the position of the first bone based on information about the position and posture of the first bone and information about the position and posture of the second bone, and derives a target relative position and a target relative posture of the second bone relative to the position and posture of the first bone based on a predetermined amount of movement relative to an initial value of the second relative position and a predetermined amount of rotation relative to an initial value of the second relative posture. The information generating unit generates an image of three-dimensional coordinate axes representing the target relative position and the target relative posture and an image of three-dimensional coordinate axes representing the second relative position and the second relative posture, The display unit displays an image of three-dimensional coordinate axes indicating the target relative position and the target relative posture, and an image of three-dimensional coordinate axes indicating the second relative position and the second relative posture.

9. A navigation system comprising: an acquisition unit, which acquires information on the position and posture of a first skeleton detected based on a signal of the first sensor and information on the position and posture of a second skeleton detected based on a signal of the second sensor, wherein: The first sensor is inserted into the mounting portion of the first fixture in a first orientation predetermined relative to the first fixture, the first fixture having a surface having a shape corresponding to the surface of the first bone, and the second sensor is inserted into the mounting portion of the second fixture in a second orientation predetermined relative to the second fixture, the second fixture having a surface having a shape corresponding to the surface of the second bone; a deriving unit that derives a relative position and a relative posture of the second bone relative to the position of the first bone based on information about the position and posture of the first bone and information about the position and posture of the second bone, and derives a target relative position and a target relative posture of the second bone relative to the position and posture of the first bone based on a predetermined amount of movement relative to an initial value of the relative position and a predetermined amount of rotation relative to an initial value of the relative posture; an information generating unit configured to generate an image of three-dimensional coordinate axes representing the target relative position and the target relative posture and an image of three-dimensional coordinate axes representing the relative position and the relative posture; as well as A display unit displays an image of three-dimensional coordinate axes indicating the target relative position and the target relative posture and an image of three-dimensional coordinate axes indicating the relative position and the relative posture.

10. A clamp, comprising: A mounting portion for inserting the sensor in a predetermined orientation; and A face whose shape corresponds to the surface of the bones to be joined.

11. The clamp according to claim 10, wherein: The first fixture comprises: a first mounting portion for inserting the first sensor in a first orientation predetermined relative to the first fixture; and a first surface having a shape corresponding to a surface of the first bone, The second fixture comprises: a second mounting portion for inserting the second sensor in a second orientation predetermined relative to the second fixture; and a second surface having a shape corresponding to the surface of the second bone, The orientation of the first mounting portion of the first sensor inserted into the first fixture in the state of being engaged with the first bone is the same as the orientation of the second mounting portion of the second sensor inserted into the second fixture in the state of being engaged with the second bone.

12. A program for causing a computer to execute the following steps: Acquiring information on the position and posture of the first sensor detected based on a signal of the first sensor and information on a target installation position and a target installation posture of the first sensor relative to the position and posture of the second sensor detected based on a signal of the second sensor, wherein: The first sensor is inserted into the mounting portion of the first fixture in a first orientation predetermined relative to the first fixture, the first fixture having a surface having a shape corresponding to the surface of the first bone, and the second sensor is inserted into the mounting portion of the second fixture in a second orientation predetermined relative to the second fixture, the second fixture having a surface having a shape corresponding to the surface of the second bone; deriving a first relative position and a first relative posture of the first sensor relative to the target installation position and the target installation posture based on the target installation position and the target installation posture and the position and posture of the first sensor; generating an image of three-dimensional coordinate axes representing the target installation position and the target installation posture and an image of three-dimensional coordinate axes representing the first relative position and the first relative posture; as well as An image of three-dimensional coordinate axes indicating the target installation position and the target installation posture and an image of three-dimensional coordinate axes indicating the first relative position and the first relative posture are displayed.

13. A program for causing a computer to execute the following steps: Acquire information about the position and posture of a first skeleton detected based on a signal of a first sensor and information about the position and posture of a second skeleton detected based on a signal of a second sensor, wherein: The first sensor is inserted into the mounting portion of the first fixture in a first orientation predetermined relative to the first fixture, the first fixture having a surface having a shape corresponding to the surface of the first bone, and the second sensor is inserted into the mounting portion of the second fixture in a second orientation predetermined relative to the second fixture, the second fixture having a surface having a shape corresponding to the surface of the second bone; Based on the information of the position and posture of the first skeleton and the information of the position and posture of the second skeleton, derive the relative position and relative posture of the second skeleton relative to the position of the first skeleton, and based on a predetermined amount of movement relative to an initial value of the relative position and a predetermined amount of rotation relative to an initial value of the relative posture, derive a target relative position and a target relative posture of the second skeleton relative to the position and posture of the first skeleton; generating an image of three-dimensional coordinate axes representing the target relative position and the target relative posture and an image of three-dimensional coordinate axes representing the relative position and the relative posture; as well as An image of three-dimensional coordinate axes indicating the target relative position and the target relative posture and an image of three-dimensional coordinate axes indicating the relative position and the relative posture are displayed.

Images