Intramedullary nail navigation system and navigation method thereof

Abstract

The present invention relates to an intramedullary nail navigation system comprising: an intramedullary nail having a distal locking hole and a proximal locking hole, each locking hole having a locking hole central axis extending in a longitudinal direction thereof; a guide for a drilling tool comprising a guide central axis extending in a longitudinal direction thereof; the electromagnetic tracking device comprises a sensing device and a tracking control unit; the sensing device is configured to track the relative posture of the drilling tool and the intramedullary nail; the tracking control unit can obtain the relative posture from the sensing device; the display device at least can display the relative posture information and instrument information related to the operation instrument; and a computing device configured to automatically determine an operation intention of a user according to the relative posture to determine whether the operation to be performed is a drill hole for implanting a locking nail or a drill hole for implanting a blocking nail. The invention also relates to a method for executing navigation by using the navigation system.

Description

Technical Field

[0001] This invention relates to navigation systems and methods for orthopedic surgery, particularly intramedullary nail implantation surgery. Background Technology

[0002] An intramedullary nail is a commonly used internal fixation device in orthopedic surgery, primarily for treating long bone fractures. It is inserted into the medullary cavity to tightly connect the two ends of the fracture, providing stable support to the bone and thus promoting fracture healing.

[0003] In intramedullary nailing surgery, in order to fix the intramedullary nail to the bones at both ends of the fracture, the intramedullary nail needs to be accurately positioned so that the surgeon knows the position of the intramedullary nail in the patient's body and the precise location of the locking hole of the intramedullary nail, so that a hole can be drilled at the location of the locking hole and the locking nail can be screwed in for fixation.

[0004] Because the locking hole is not visible after the intramedullary nail is inserted into the medullary cavity, three common methods are used to align the locking nail with the locking hole: C-arm fluoroscopy guidance, mechanical guidance, and computer-aided guidance. C-arm fluoroscopy guidance exposes the patient to a certain dose of radiation, while mechanical guidance can lead to difficulties in distal locking due to deformation of the intramedullary nail during insertion. Computer-aided guidance significantly reduces radiation exposure and avoids the effects of intramedullary nail deformation.

[0005] Furthermore, intramedullary nail navigation involves different drill sleeves and intramedullary nail sizes. A common method is for the user to specify the sleeve and nail to be used via a graphical interface. This method requires user interaction, is not only cumbersome but also prone to errors.

[0006] Currently, there is still a need for an improved navigation system to accurately guide doctors in implanting intramedullary nails while significantly reducing radiation exposure to patients under C-arm fluoroscopy. Summary of the Invention

[0007] One object of the present invention is to solve at least one aspect of the aforementioned problems and defects existing in the prior art.

[0008] According to one aspect of the present invention, an intramedullary nail navigation system is provided, comprising: an intramedullary nail having a distal locking hole and a proximal locking hole, each locking hole having a locking hole central axis extending in its longitudinal direction; a guide for a drill bit, the guide including a guide central axis extending in its longitudinal direction; an electromagnetic tracking device including a sensing device configured to track the relative attitude of the drill bit and the intramedullary nail and a tracking control unit capable of acquiring the relative attitude from the sensing device; a display device capable of displaying at least the relative attitude information and instrument information related to the operation of the instrument; and a computing device configured to automatically determine the user's operating intention based on the relative attitude to determine whether the operation to be performed is drilling for implanting a locking nail or drilling for implanting a blocking nail, wherein, if the operation to be performed is drilling for implanting a locking nail, the intramedullary nail navigation system performs navigation for aiming the locking nail drilling operation; and if the operation to be performed is drilling for implanting a blocking nail, the intramedullary nail navigation system performs navigation for aiming the blocking nail drilling operation.

[0009] Optionally, the relative attitude includes the angle between the center axis of the locking hole and the center axis of the guide and / or the volume ratio of the portion of the guide that falls into a predefined three-dimensional space relative to the volume of the guide.

[0010] Optionally, the included angle is the projection angle formed by the projections of the drill bit's central axis and the locking hole's central axis onto a plane that includes or is parallel to the locking hole's central axis. The computing device is further configured to determine whether the included angle is within a predetermined range, wherein if the included angle is ≥ 45 degrees and ≤ 135 degrees, the computing device determines that the operation to be performed is drilling for inserting a stop pin; if the included angle is less than 45 degrees or greater than 135 degrees, the computing device determines that the operation to be performed is drilling for inserting a locking pin.

[0011] Optionally, the predefined three-dimensional space includes a first space adjacent to and surrounding the distal locking hole, a second space adjacent to and surrounding the proximal locking hole, and a third space adjacent to but not surrounding the locking hole, wherein the first, second, and third spaces do not overlap, and the computing device is further configured to determine whether the volume ratio of the portion of the guide falling into the first, second, or third space relative to the guide is within a predetermined range, wherein if the volume ratio of the guide falling into the first space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for inserting a locking pin in the distal locking hole; if the volume ratio of the guide falling into the second space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for inserting a locking pin in the proximal locking hole; and if the volume ratio of the guide falling into the third space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for inserting a blocking pin.

[0012] Optionally, the relative attitude also includes the distance between the center axis of the locking hole and the center axis of the guide, and the computing device is further configured to: compare the distance between the center axis of the guide and the center axis of the locking hole of each locking hole before confirming whether the included angle and / or the volume ratio is within a predetermined range, to determine whether the operation to be performed is for the distal locking hole or the proximal locking hole.

[0013] Optionally, the computing device is further configured to: in navigation for aiming a locking nail hole, determine whether the drill bit can enter the range of the locking hole to be aimed based on the relative attitude, thereby determining whether the drill bit is aligned with the locking hole to be aimed; and in navigation for aiming a blocking nail hole, determine whether the drill bit is aimed at the outside of the intramedullary nail based on the relative attitude.

[0014] Optionally, the tracking control unit is configured to create a 3D model of the drill string and a 3D model of the intramedullary nail, the 3D model of the intramedullary nail including a 3D model of the locking hole, and the computing device is further configured to determine, by means of the 3D model of the drill string and the 3D model of the locking hole, whether the drill string is aligned with the locking hole to be aimed, and to send a command to the display device to display the aligned or misaligned state.

[0015] Optionally, the computing device is further configured to determine that the drill bit is aligned with the lock hole to be targeted when the computing device calculates that the cut profile obtained by the intersection of the tangent plane of the drill bit 3D model and the locking hole 3D model (i.e., the plane where the end face of the locking hole is located) is within the range of the end face profile of the locking hole 3D model.

[0016] Optionally, the computing device is further configured to calculate the distance between the outer periphery of the drill bit used for the stop nail drilling and the outer periphery of the adjacent intramedullary nail, and to determine whether the distance is less than a predetermined threshold and send an instruction to the display device to perform a corresponding display, wherein the predetermined threshold is a distance value of 1 mm, and if the distance is less than the predetermined threshold, the computing device confirms the target drilling location where the stop nail can be implanted.

[0017] Optionally, the display device is configured to display, in response to instructions from the computing device, a locking pin drilling aiming operation or a blocking pin drilling aiming operation, to indicate whether the drill bit is misaligned or aligned with the locking hole to be aimed, or to indicate whether the drill bit is aimed at the outside of the intramedullary nail.

[0018] Optionally, the sensing device includes at least one electromagnetic sensor disposed within the intramedullary nail and at least one magnetic field generator disposed in the guide for the drill bit.

[0019] Optionally, the intramedullary nail navigation system also includes a connection line for connecting to an electromagnetic sensor. The electromagnetic sensor is connected to an interface control unit via the connection line. The connection line includes a connection line interface and a storage chip disposed in the connection line interface. Instrument information related to the type and specifications of the intramedullary nail can be written into and stored in the storage chip. Thus, when the interface control unit is connected to the tracking control unit, the tracking control unit can automatically read the current instrument information and send it to the computing device for display on the display device.

[0020] According to another aspect of the present invention, a method for performing navigation using the aforementioned intramedullary nail navigation system is provided, the method comprising: a) A tracking step, in which the relative attitude of the drill string and the intramedullary nail is tracked using the sensing device of the electromagnetic tracking device, and a 3D model of the drill string and a 3D model of the intramedullary nail are established using the tracking control unit of the electromagnetic tracking device, wherein the 3D model of the intramedullary nail includes a 3D model of the locking hole; and b) The step of automatically determining the operation intention, wherein a computing device determines, based on the relative posture, whether the operation to be performed is drilling for inserting a locking pin or drilling for inserting a blocking pin. Specifically, when the operation to be performed is drilling for implanting a locking screw, the intramedullary nail navigation system performs navigation for aiming the locking screw drilling operation; when the operation to be performed is drilling for implanting a blocking screw, the intramedullary nail navigation system performs navigation for aiming the blocking screw drilling operation.

[0021] Optionally, the relative posture includes the angle between the center axis of the locking hole and the center axis of the guide and / or the volume ratio of the portion of the guide falling into a predefined three-dimensional space relative to the volume of the guide, and the step of automatically determining the operating intention includes confirming whether the angle and / or the volume ratio are within a predetermined range.

[0022] Optionally, the included angle is the projection angle formed by the projection of the drill bit center axis and the locking hole center axis onto a plane that includes or is parallel to the locking hole center axis. When the included angle is ≥ 45 degrees and ≤ 135 degrees, the computing device determines that the operation to be performed is drilling for inserting a stop pin; when the included angle is less than 45 degrees or greater than 135 degrees, the computing device determines that the operation to be performed is drilling for inserting a locking pin. Additionally or alternatively, the predefined three-dimensional space includes a first space adjacent to and surrounding the distal locking hole, a second space adjacent to and surrounding the proximal locking hole, and a third space adjacent to but not surrounding the locking hole, wherein the first, second, and third spaces do not overlap. When the volume ratio of the guide falling into the first space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for inserting a locking pin in the distal locking hole; when the volume ratio of the guide falling into the second space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for inserting a locking pin in the proximal locking hole; when the volume ratio of the guide falling into the third space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for inserting a blocking pin.

[0023] Optionally, the relative attitude also includes the distance between the center axis of the locking hole and the center axis of the guide, and the computing device is further configured to: compare the distance between the center axis of the guide and the center axis of the locking hole of each locking hole before confirming whether the included angle and / or the volume ratio is within a predetermined range, to determine whether the operation to be performed is for the distal locking hole or the proximal locking hole.

[0024] Optionally, the method is further used to aim the drill bit at the locking hole of the intramedullary nail during locking nail drilling navigation in the intramedullary nail navigation system, and the method further includes the following steps: c) A determination step, in which a computing device determines, based on the relative attitude, whether the drill bit can enter the range of the target locking hole as it travels along its axial direction; and d) Display step: In the display step, the locking pin drilling aiming operation is displayed using a display device to show whether the drill bit and the locking hole to be aimed are in a misaligned or aligned state. In the determination step, the computing device uses the 3D model of the drill bit and the 3D model of the locking hole to determine whether the drill bit is aligned with the locking hole to be aimed, and sends a command to the display device to display the aligned or unaligned state.

[0025] Optionally, the method further includes obtaining a first spatial transformation from the drill string 3D model to the intramedullary nail 3D model, and obtaining a second spatial transformation from the intramedullary nail 3D model to the drill string 3D model.

[0026] Optionally, the method further includes: obtaining the transformation of the drill bit 3D model to the proximal tangent plane of the locking hole and the transformation of the drill bit 3D model to the distal tangent plane of the locking hole relative to the position and orientation of the proximal tangent plane (the plane where the proximal end face of the locking hole is located) and the distal tangent plane (the plane where the distal end face of the locking hole is located) of the locking hole relative to the intramedullary nail 3D model, and the transformation of the drill bit 3D model to the distal tangent plane of the locking hole based on the first spatial transformation and the second spatial transformation.

[0027] Optionally, the method further includes: Obtain the spatial transformation from the near and far tangent planes of the locking hole to the 3D model of the drill string; The 3D model of the drill bit is extended to obtain a virtual drill bit extension model outline, which intersects with the near-side tangent plane and the far-side tangent plane of the locking hole, respectively, and generates a near-side intersection outline and a far-side intersection outline. Obtain the corresponding spatial transformations of the proximal and distal intersecting contour lines to the proximal and distal tangent planes of the locking hole; and Determine whether the proximal intersecting contour lines and the distal intersecting contour lines are respectively located within the proximal end face contour and the distal end face contour of the locking hole.

[0028] Optionally, the method further includes operating the intramedullary nail navigation system to aim the stopper nail at the outer side of the intramedullary nail during stopper nail drilling navigation. The determination step further includes using a computing device to calculate the distance between the outer periphery of the drill bit used for stopper nail drilling and the outer periphery of the adjacent intramedullary nail. The computing device is also used to determine whether the distance is less than a predetermined threshold, where the predetermined threshold is a distance value of 1 mm. If the distance is less than the predetermined threshold, the computing device confirms the target drilling location for stopper nail implantation and sends a command to a display device for corresponding display. The display step further includes using the display device to display the stopper nail drilling aiming operation in response to the command.

[0029] This invention realizes a simple and easy-to-use intramedullary nail navigation system and method based on electromagnetic tracking technology. By fixing a magnetic field generator inside the drill guide (sleeve), handheld sleeve tracking can be achieved. Furthermore, the intramedullary nail navigation system according to this invention can automatically determine the user's operating intention, store and automatically retrieve instrument information, and determine the relative position of the drill and the intramedullary nail without parameters, thereby achieving seamless integration of accuracy verification, borehole navigation, and stop nail navigation workflows. Attached Figure Description

[0030] The invention will now be described in detail with reference to the accompanying drawings, which are non-limiting embodiments. The drawings are merely illustrative and not necessarily drawn to scale. Furthermore, they show only those parts necessary to illustrate the invention, while other parts may be omitted or simply mentioned. That is, the invention may include other parts besides those shown in the drawings. In the figures, similar elements or parts are indicated by the same reference numerals, wherein... Figure 1 A portion of an existing intramedullary nail is shown in a schematic perspective view, including a locking hole; Figure 2 A schematic diagram of an intramedullary nail navigation system according to an embodiment of the present invention is shown. Figure 3a and Figure 3b The invention schematically illustrates the concept and method for automatically determining user intent in an intramedullary nail navigation system according to an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the locking nail drilling aiming operation performed using an intramedullary nail navigation system according to an embodiment of the present invention; Figure 5 It schematically shows that in Figure 4 The diagram shows the misaligned and aligned states during the locking pin drilling aiming operation. Figure 6 This is a schematic diagram illustrating the blocking nail drilling aiming operation performed using an intramedullary nail navigation system according to an embodiment of the present invention; Figure 7 It schematically shows that in Figure 6 The diagram shows the unsuitable and suitable insertion positions during the drilling and aiming operation of the stop pin. Figure 8 This diagram schematically illustrates how an intramedullary nail navigation system, according to an embodiment of the present invention, makes decisions during the navigation of a locking nail drilling process. Detailed Implementation

[0031] The following description, with reference to the accompanying drawings, describes an intramedullary nail navigation system according to an embodiment of the present invention and a method for performing navigation using the system. In the following description, numerous specific details are set forth to enable those skilled in the art to gain a more complete understanding of the invention. However, it will be apparent to those skilled in the art that implementation of the invention may not include some of these specific details. Furthermore, it should be understood that the invention is not limited to the specific embodiments described. Rather, the invention can be conceived to be practiced with any combination of the following features and elements, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are illustrative only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.

[0032] Intramedullary nail navigation typically includes drilling navigation and stop screw navigation. Drilling navigation guides the drill bit (e.g., a drill) to drill a hole in the bone along the locking hole axis to insert the locking screw and prevent the intramedullary nail from moving within the medullary cavity. Stop screw navigation guides the stop screw to be inserted along the outer edge of the intramedullary nail at an angle to the locking hole axis to prevent the intramedullary nail from moving along the locking hole axis. The underlying logic for drilling navigation and stop screw navigation differs. For example, to determine whether the drill bit can pass smoothly through the locking hole (i.e., whether the drill bit is aligned with the locking hole), the parameter-free determination method proposed in this disclosure (see below) can be used, or the distance and angle between the drill bit axis and the locking hole axis can be used. When inserting the stop screw, the distance between the drill bit's central axis and the edge of the intramedullary nail is required. Due to the different logic, the navigation system needs to know what operation the user (or operator, such as a physician) is currently performing in order to determine whether to perform locking screw drilling navigation or stop screw drilling navigation. The existing method involves users specifying the operation to be performed through buttons on a graphical interface.

[0033] This disclosure aims to automatically determine the user's operational intent and automatically switch the judgment logic without interaction, thereby improving the usability of the navigation system. To achieve automatic intent determination, the operating area around the intramedullary nail can be divided into a blocking nail area and a drilling area. Figure 1 An intramedullary nail is schematically shown with two locking holes, one distal locking hole 10 and the other proximal locking hole 12. Each locking hole involves both locking screw drilling and blocking screw drilling; therefore, to achieve automatic user intent determination, the different locking holes must first be distinguished. See also Figure 3a It can be accessed through the middle dividing line between the two locking holes 10 and 12 ( Figure 3a The vertical lines in the diagram are used to distinguish different locking holes. Additionally, see... Figure 3bThe two operating areas, locking pin drilling and blocking pin drilling, can be distinguished by the angle α between the drill bit axis and the locking hole axis. Figure 3a The front of the locking hole is shown. Figure 3b The side of the locking hole is shown. Figure 3b In the side view, if the angle α between the drill string axis and the locking hole axis is between 45 degrees and 135 degrees (e.g., Figure 3b If the middle triangular area is shown, it indicates that the user is about to perform a blocking pin drilling operation; otherwise, it indicates a locking pin drilling operation (at which point the drill axis direction may be in the middle of the triangle area). Figure 3b (in the triangular regions on both sides).

[0034] The following is a detailed explanation with reference to the accompanying drawings.

[0035] Figure 1 A portion of an existing intramedullary nail is schematically shown. The intramedullary nail 1 may have two locking holes 10, 12, for example, a smaller distal locking hole 10 with a diameter of, for example, about 4.6 mm; and a larger proximal locking hole 12 with a diameter of, for example, about 5.3 mm.

[0036] Intramedullary nail navigation technology aims to precisely guide the implantation of intramedullary nails, including locking screw drilling navigation and blocking screw drilling navigation. Locking screw drilling navigation is used to aim the drill at the locking hole of the intramedullary nail, while blocking screw drilling navigation is used to confirm the appropriate implantation position of the blocking screw.

[0037] Navigating a locking pin drill hole requires determining the spatial relationship between the drill bit and the locking hole, and informing the user whether the drill bit is aligned with the locking hole. To determine this relationship, threshold values ​​for angle and distance can be preset. For example, if both the distance and angle between the drill bit's center axis and the locking hole's center axis are less than a certain threshold, alignment is considered achieved. This method typically requires a graphical interface to provide input, allowing users to set different threshold values.

[0038] This disclosure proposes a method for intuitively determining the spatial positional relationship between a drill bit and a locking hole. Specifically, this method determines the spatial positional relationship between the 3D model of the locking hole and the 3D model of the drill bit based on their geometric relationship. That is, it determines whether the two are aligned based on the spatial positional relationship between the near and far tangent planes of the drill bit along its axial direction and the near and far end faces of the locking hole. This method does not require setting any parameters, maximizes the operable space, and is simple to implement.

[0039] Figure 2 A schematic overall diagram of an intramedullary nail navigation system according to an embodiment of the present invention is shown. Figure 2In the illustrated embodiment, the intramedullary nail navigation system 100 uses the sensing device 110 of the electromagnetic tracking device to track the relative attitude of the drill string and the intramedullary nail 1, and uses the tracking control unit 120 of the electromagnetic tracking device to establish a 3D model of the drill string (replaced by a 3D model of the guide) and a 3D model of the intramedullary nail and calculate the spatial positional relationship between them. For this purpose, an electromagnetic sensor 30a and a magnetic field generator 30b can be implanted in the intramedullary nail 1 and the guide 20 for the drill string, respectively. The electromagnetic sensor 30a is placed into the intramedullary nail 1 using a probe 16. The guide 20 can be in the form of a sleeve, which can be fitted onto the outside of the drill string.

[0040] exist Figure 2 In the diagram, dashed lines with arrows represent a series of spatial transformations during the conversion from the guide 3D model to the intramedullary nail 3D model, while solid lines without arrows represent the connections between the electromagnetic sensor 30a, the magnetic field generator 30b, the interface control unit 140, the tracking control unit 120, and the computing device 130. The spatial transformation between the guide 3D model and the magnetic field generator 30b is completed through a pre-shipment calibration process. A display device (not shown) can display the relative attitude information of the drill string (or guide) and the intramedullary nail, as well as instrument information related to the operating instruments.

[0041] In addition, a connecting cable is provided for the electromagnetic sensor 30a, which is connected to the interface control unit 140 via the connecting cable. The connecting cable includes a connecting cable interface and a storage chip disposed in the connecting cable interface. Instrument information related to the type and specifications of the intramedullary nail can be written to and stored in the storage chip. Sleeve information is stored in the computer 130.

[0042] The computing device 130 can be configured to automatically determine the user's operational intention based on the relative posture, to determine whether the operation to be performed is drilling for implanting a locking screw or drilling for implanting a blocking screw. If the operation to be performed is drilling for implanting a locking screw, the intramedullary nail navigation system performs navigation for aiming the locking screw drill; if the operation to be performed is drilling for implanting a blocking screw, the intramedullary nail navigation system performs navigation for aiming the blocking screw drill.

[0043] To this end, the computing device 130 can also be configured to confirm whether the included angle α between the center axis of the locking hole and the center axis of the guide is within a predetermined range. If the included angle α is within the predetermined range, the computing device 130 determines whether the operation to be performed is drilling for inserting a stop pin or drilling for inserting a locking pin.

[0044] The aforementioned included angle α can be the projection angle formed by the projections of the drill bit's central axis and the locking hole's central axis onto a plane containing or parallel to the locking hole's central axis. When the included angle α is ≥ 45 degrees and ≤ 135 degrees, the computing device determines that the operation to be performed is drilling for inserting a stop pin. When the included angle α is less than 45 degrees or greater than 135 degrees, the computing device determines that the operation to be performed is drilling for inserting a locking pin. Other predetermined ranges are conceivable, as long as they are suitable for inserting a locking pin or a stop pin.

[0045] To enable automatic determination of user intent, the aforementioned relative posture may alternatively or additionally include the relative position of the guide 20 relative to a predefined three-dimensional space. For example, a three-dimensional space may be predefined around the proximal locking hole 12, slightly larger than the proximal locking hole 12 to surround it. If a portion of the guide 20 (represented by a 3D model of the guide) greater than or equal to 1 / 2 (or a larger proportion, such as 3 / 5) of its total volume falls into this space, it is determined that the user intends to drill a hole to insert a locking pin into the proximal locking hole 12.

[0046] Similarly, another three-dimensional space can be predefined around the distal locking hole 10, slightly larger than the distal locking hole 10 to surround it, and not overlapping with the predefined three-dimensional space for the proximal locking hole 12 described above. If a portion of the guide 20 with a volume ratio greater than or equal to, for example, 1 / 2 (or a larger proportion, such as 3 / 5) falls into this space, it is determined that the user intends to drill a hole to insert a locking pin into the distal locking hole 10.

[0047] Furthermore, another three-dimensional space can be predefined near the proximal locking hole 12 and / or the distal locking hole 10. For example, a corresponding three-dimensional space can be predefined between the proximal locking hole 12 and the distal locking hole 10, which does not coincide with any of the predefined three-dimensional spaces surrounding the locking holes 10 and 12 described above. If a portion of the guide 20 with a volume ratio greater than or equal to, for example, 1 / 2 (or a larger proportion, such as 3 / 5) falls into this space, it can be determined that the user intends to drill a hole for implanting a stop pin.

[0048] The aforementioned relative posture may also include the distance between the central axis of the locking hole and the central axis of the guide. Before confirming whether the aforementioned included angle α and / or the proportion of the guide portion falling into the predefined three-dimensional space to the total volume of the guide (hereinafter referred to as "proportion" or "volume ratio") are within a predetermined range, the computing device 130 may also compare the distance between the central axis of the guide 20 and the central axes of each locking hole 10, 12 to determine whether the operation to be performed is for the distal locking hole 10 or the proximal locking hole 12. For example, if the guide 20 is closer to the distal locking hole 10, it is determined that the operation to be performed is for that distal locking hole.

[0049] Electromagnetic sensor 30a can be connected to tracking control unit 120 via interface control unit 140. Magnetic field generator 30b is also connected to tracking control unit 120. Spatial transformations from the guide 3D model to the magnetic field generator 30b within the guide 20 and from the intramedullary nail 3D model to the electromagnetic sensor 30a within the intramedullary nail 1 are obtained through calibration. The spatial transformation from electromagnetic sensor 30a to magnetic field generator 30b is provided by an electromagnetic tracking device. This will be described in detail below.

[0050] The intramedullary nail navigation system 100 of the present invention can be configured to aim the drill bit at the distal locking hole 10 or the proximal locking hole 12 of the intramedullary nail 1 during locking nail drilling navigation of the intramedullary nail navigation system. Figure 4 The diagram illustrates how to perform a locking nail drilling aiming operation using an intramedullary nail navigation system 100 according to an embodiment of the present invention.

[0051] As previously mentioned, in order to track the relative orientation of the drill string and locking holes 10, 12, a guide 20 for the drill string can be used within the intramedullary nail 1 (see [link to documentation]). Figure 2 An electromagnetic sensor 30a and a magnetic field generator 30b are respectively installed inside the drill string. The guide 20 is in the form of a sleeve. Since the magnetic field generator cannot be directly installed in the drill string, it can be installed in the guide 20, which is arranged coaxially with the drill string. In one example, the magnetic field generator used is the Planar FG10-11 magnetic field generator from NDI (Northern Digital Inc.). After encapsulating the magnetic field generator 30b and the guide 20 (i.e., the sleeve), a handheld, trackable sleeve can be made.

[0052] The relative orientation of the locking holes 10 and 12 of the intramedullary nail 1 with the electromagnetic sensor 30a in the intramedullary nail 1 is obtained through factory calibration. Thus, with the help of the electromagnetic sensor 30a and the magnetic field generator 30b, the relative orientation of the drill bit with the locking holes 10 and 12 can be tracked in real time.

[0053] The aiming method proposed in this invention does not rely on a specific tracking method. In this embodiment, an electromagnetic tracking method is used, namely, a magnetic field generator and an electromagnetic sensor are implanted in the drill guide 20 and the intramedullary nail 1, respectively, to track their relative attitude. The method proposed in this invention is also applicable to other tracking methods, such as fixing the electromagnetic sensor in the guide 20 and arranging a separate magnetic field generator outside the guide 20 to track the relative attitude of the guide 20 (and thus the drill) and the intramedullary nail 1, or using an optical tracking method, etc.

[0054] The intramedullary nail navigation system 100 according to an embodiment of the present invention may further include a computing device 130 (see Figure 2The computing device 130 is used to determine, based on the relative attitude, whether the drill bit can enter the range of the lock hole 10 or 12 to be aimed at along its axial direction, thereby determining whether the drill bit is aligned with the lock hole 10 or 12 to be aimed at. The term "alignment" as used herein should be interpreted broadly within the technical field; that is, "alignment" does not mean strict geometric and mathematical alignment, but rather refers to overall suitability for drilling operations, for example, in the case of aiming at a lock hole, meaning that the drill bit can pass smoothly through the lock hole.

[0055] Figure 5 It schematically shows that in Figure 4 The diagram shows the misaligned and aligned states during the locking pin drilling aiming operation.

[0056] Therefore, the intramedullary nail navigation system 100 according to an embodiment of the present invention may further include a display device (not shown). The display device can be used to display the locking nail drilling aiming operation to show whether the drill bit is misaligned or aligned with the locking hole 10 or 12 to be aimed. The display device may be a computer monitor.

[0057] When the alignment of the drill bit with the locking hole changes, the characteristics of the drill bit's projection, such as its color, can be changed accordingly. For example, when the drill bit moves to aim / align with the locking hole, the projection color can be changed from red to green; when the drill bit moves away from the locking hole, the color can be changed from green to red. A similar setting can be used when performing drill bit aiming operations to insert stop pins. As for what constitutes "aiming" and what constitutes "deviation," different determination methods can be used for locking pin drilling operations and stop pin drilling operations, respectively.

[0058] The tracking control unit 120 can create a 3D model 20' of the drill bit and a 3D model 1' of the intramedullary nail, wherein the 3D model of the intramedullary nail includes a 3D model 10' of the locking hole. If the computing device 130 calculates that the cut profile obtained by the intersection of the plane (tangent plane) containing the end face of the drill bit 3D model and the locking hole 3D model is within the range of the end face profile of the locking hole 3D model, it can be determined that the drill bit is aligned with the locking hole to be targeted. The drill bit can then travel along the current axial direction, perform drilling operations, and smoothly enter the corresponding locking hole 10 or 12.

[0059] When the computing device 130 determines that the drill bit is aligned with the lock hole to be aimed, the computing device 130 sends a command to the display device to display the alignment status.

[0060] If the computing device 130 calculates that the cut profile obtained by the intersection of the plane (cutting plane) where the end face of the drill bit 3D model and the locking hole 3D model are located at least partially exceeds the range of the end face profile of the locking hole 3D model, the computing device 130 determines that the drill bit and the locking hole to be aimed are not aligned, and sends a command to the display device to display the misalignment state.

[0061] The display on the display device regarding the aiming operation of the locking pin drilling can include a first identifier and a second identifier different from the first identifier.

[0062] like Figure 5 As shown, the first indicator can be a red circle to indicate a misaligned state, and the second indicator can be a green circle to indicate an aligned state. Therefore, when the drill bit deviates from the locking hole, the drill bit model on the screen displays red; when the drill bit is aligned with the locking hole, the drill bit model displays green. Since only the color of the drill bit model changes during aiming rather than suddenly introducing new information, the doctor's attention can remain focused on the drill bit model, making the aiming operation undisturbed.

[0063] The intramedullary nail navigation system 100 according to an embodiment of the present invention can also be configured to aim the stop nail at the outer side of the intramedullary nail when the intramedullary nail navigation system performs stop nail drilling navigation. Figure 6 The diagram illustrates the use of the intramedullary nail navigation system 100 to perform a blocking nail drilling aiming operation.

[0064] The blocking nail will be inserted along the outside of the intramedullary nail 1 to prevent the intramedullary nail 1 from moving along the axial direction of the locking holes 10, 12.

[0065] Therefore, such as Figure 6 As shown, the computing device 130 can also calculate the distance between the outer periphery of the drill bit (and therefore the outer periphery of the stop pin) and the outer periphery of the adjacent intramedullary nail, and the computing device 130 can also determine whether the distance is less than a predetermined threshold. If the distance is less than the predetermined threshold, the computing device 130 confirms the target drilling position for stop pin implantation and sends a command to the display device for corresponding display. The display device can also display the stop pin drilling aiming operation in response to the command. Alternatively, the distance can be defined as the distance between the central axis of the drill bit (and therefore the central axis of the stop pin) and the central axis of the intramedullary nail, and an appropriate threshold can be set for it.

[0066] Figure 7 It schematically shows that in Figure 6 The diagram illustrates unsuitable and suitable insertion positions during the drilling and aiming operation of the stop pin. For example... Figure 7As shown, the display device's display of the blocking nail drilling aiming operation may include a third indicator. If the distance is less than a predetermined threshold, the third indicator is displayed as a green circular pattern, indicating that the current position of the blocking nail is suitable for implantation; otherwise, it is displayed as a red circular pattern.

[0067] When the aforementioned distance refers to the distance between the outer periphery of the drill bit and the outer periphery of the adjacent intramedullary nail, a predetermined threshold of approximately 1 mm can be defined. That is, when the distance between the outer periphery of the drill bit and the outer periphery of the adjacent intramedullary nail is less than or equal to 1 mm, a third indicator (green circular pattern) can be displayed; otherwise, a red circular pattern is displayed. There are two cases in this case: one is the distance between the outer periphery of the drill bit (see...) Figure 6 14' in the middle) is far from the peripheral outline of the intramedullary nail (see 14' in the middle) Figure 6 (1') 1 mm, the drill bit can drill without contact with the intramedullary nail. Another case is the outer circumferential profile of the drill bit (see...) Figure 6 The 14” in the middle is located within the outer contour of the intramedullary nail, with a 1 mm overlap / intersection between the two, allowing the drill bit to rub against the intramedullary nail when drilling. Both of these scenarios are feasible.

[0068] Figure 8 This illustration schematically shows how an intramedullary nail navigation system 100, according to an embodiment of the present invention, makes decisions during the navigation of a locking nail drill hole. For example... Figure 8 As shown, the extended model of the drill bit intersects the near and far tangent planes of the locking hole (the planes where the near and far end faces are located). If the near and far cut profiles are completely within the locking hole cut, then the drill bit is completely within the locking hole.

[0069] Specifically, the 3D model of the drill bit is extended by 100 mm. If the cut contours of the extended 3D model of the drill bit and the near and far tangential planes of the locking hole are within the end face contour of the locking hole, then the drill bit is completely located within the locking hole. The extension line of the drill bit is used here because during navigation, before the drill bit has actually entered the locking hole, it is necessary to determine whether the drill bit can successfully enter the locking hole along the current aiming direction.

[0070] The navigation method using the intramedullary nail navigation system 100 according to an embodiment of the present invention includes the following steps: a) Tracking step, in which the relative attitude of the drill string and the intramedullary nail 1 is tracked using the sensing device 110 of the electromagnetic tracking device, and a 3D model 20' of the drill string is established using the tracking control unit 120 of the electromagnetic tracking device (see...). Figure 8 ) and intramedullary nail 3D model 1' (see Figure 6 The intramedullary nail 3D model includes locking hole 3D models 10' and 12' (see...). Figure 6 , Figure 8 );and b) The step of automatically determining the operation intention, wherein the computing device 130 determines whether the operation to be performed is drilling for inserting a locking pin or drilling for inserting a blocking pin.

[0071] When the operation to be performed is drilling for implanting a locking screw, the intramedullary nail navigation system 100 performs navigation for aiming the locking screw drilling operation; when the operation to be performed is drilling for implanting a blocking screw, the intramedullary nail navigation system 100 performs navigation for aiming the blocking screw drilling operation.

[0072] The aforementioned step of automatically determining the operation intention may include confirming whether the included angle α and / or volume ratio are within a predetermined range. If either the included angle α or the volume ratio is within the corresponding predetermined range, the computing device 130 determines that the operation to be performed is drilling for implanting a stop pin or implanting a corresponding locking pin.

[0073] The included angle α is the projection angle formed by the projections of the drill bit's central axis and the locking hole's central axis onto a plane that includes or is parallel to the locking hole's central axis. When the included angle α is ≥ 45 degrees and ≤ 135 degrees, the calculation device determines that the operation to be performed is drilling for inserting a stop pin; when the included angle α is less than 45 degrees or greater than 135 degrees, the calculation device determines that the operation to be performed is drilling for inserting a locking pin.

[0074] The aforementioned relative orientation may also include the distance between the center axis of the locking hole and the center axis of the guide. The computing device 130 may compare the distance between the axis of the guide 20 and the axis of each locking hole before confirming whether the included angle α and / or volume ratio are within a predetermined range to determine whether the operation to be performed is for the distal locking hole 10 or the proximal locking hole 12.

[0075] The navigation method according to an embodiment of the present invention is further used to aim the drill bit (guide 20) at the distal locking hole 10 or the proximal locking hole 12 of the intramedullary nail 1 during locking nail drilling navigation in the intramedullary nail navigation system. To this end, the navigation method according to an embodiment of the present invention may further include the following steps: c) A determination step, in which the computing device 130 determines, based on the relative attitude, whether the drill bit can enter the range of the target locking hole 10 or 12 as it travels along its axial direction; and d) Display step, in which the display device displays the aiming operation of the locking pin drilling, so as to show that the drill bit and the locking hole to be aimed are in a misaligned state or an aligned state.

[0076] In the determination step, the computing device 130 can determine whether the drill bit is aligned with the locking hole to be aimed by means of the drill bit 3D model 20' and the intramedullary nail 3D model 1', and send a command to the display device to display the aligned or unaligned state.

[0077] The method may further include: obtaining a first spatial transformation from the drill string 3D model 20' to the intramedullary nail 3D model 1', and obtaining a second spatial transformation from the intramedullary nail 3D model 1' to the drill string 3D model 20'.

[0078] The method may further include: obtaining the transformation of the drill bit 3D model to the proximal tangent plane of the locking hole and the transformation of the drill bit 3D model to the distal tangent plane of the locking hole relative to the position and orientation of the proximal tangent plane (the plane where the proximal end face of the locking hole is located) and the distal tangent plane of the locking hole relative to the intramedullary nail 3D model, and obtaining the transformation of the drill bit 3D model to the proximal tangent plane of the locking hole and the transformation of the drill bit 3D model to the distal tangent plane of the locking hole based on the position and orientation of the proximal tangent plane (the plane where the proximal end face of the locking hole is located) and the distal tangent plane of the locking hole relative to the position and orientation of the proximal tangent plane of the locking hole and the distal tangent plane of the locking hole based on the first spatial transformation and the second spatial transformation.

[0079] In this paper, "proximal" refers to the side closer to the user / operator, and "distal" refers to the side farther from the user / operator. In descriptions related to the decision-making steps, "tangential plane" refers to a virtual plane in the 3D model.

[0080] Furthermore, the method may also include: obtaining spatial transformations of the proximal and distal tangent planes of the locking hole to the 3D model of the drill string; extending the 3D model of the drill string to obtain virtual extended model contours of the drill string, the virtual extended model contours of the drill string intersecting the proximal and distal tangent planes of the locking hole respectively, and generating proximal intersecting contour lines and distal intersecting contour lines (also known as "proximal cuts and distal cuts"); obtaining corresponding spatial transformations of the proximal and distal intersecting contour lines to the proximal and distal tangent planes of the locking hole; and determining whether the proximal and distal intersecting contour lines are respectively located within the proximal end face contour and the distal end face contour of the locking hole.

[0081] The navigation method according to an embodiment of the present invention can also be performed by operating the intramedullary nail navigation system 100 to aim the stop nail at the outer side of the intramedullary nail 1 during stop nail drilling navigation in the intramedullary nail navigation system. For this purpose, the determination step may further include using a computing device to calculate the distance between the outer periphery of the drill bit used for stop nail drilling and the outer periphery of the adjacent intramedullary nail, and the computing device 130 is further configured to determine whether the distance is less than a predetermined threshold. The predetermined threshold may be a distance value of 1 mm. If the distance is less than the predetermined threshold, the computing device 130 confirms the target drilling position available for stop nail implantation and sends a command to a display device, and the display device displays the stop nail drilling aiming operation in accordance with the command.

[0082] The method for determining the spatial position of the drill bit and locking hole proposed in this invention can maximize the user's operating space.

[0083] Although the preceding examples illustrated how to determine alignment by establishing relevant models and performing spatial transformations, it is also conceivable that the alignment of the drill bit with the locking hole could be determined by the positional relationship between the central axis of the intramedullary nail's locking hole and the central axis of the drill bit (e.g., the distance and angle between the two central axes).

[0084] Those skilled in the art will understand that the embodiments described above are exemplary and can be improved upon. The structures described in the various embodiments can be freely combined without causing any conflict in structure or principle.

[0085] After a detailed description of the preferred embodiments of the present invention, those skilled in the art will clearly understand that various changes and modifications can be made without departing from the scope and spirit of the appended claims, and that the present invention is not limited to the embodiments described in the specification.

Claims

1. An intramedullary nail navigation system (100), comprising: An intramedullary nail (1) having a distal locking hole (10) and a proximal locking hole (12), each locking hole having a locking hole central axis extending in its longitudinal direction; A guide (20) for a drill bit, the guide including a guide center axis extending in its longitudinal direction; An electromagnetic tracking device (110) includes a sensing device configured to track the relative attitude of the drill bit and the intramedullary nail, and a tracking control unit (120) capable of acquiring the relative attitude from the sensing device. The display device is capable of displaying at least the relative posture information and the instrument information related to the operation of the instrument; A computing device configured to automatically determine the user's operational intention based on the relative posture, to determine whether the operation to be performed is drilling for inserting a locking pin or drilling for inserting a blocking pin. In the case where the operation to be performed is drilling for implanting a locking nail, the intramedullary nail navigation system performs navigation for aiming the locking nail drilling operation; When the operation to be performed is drilling for the implantation of a stop nail, the intramedullary nail navigation system performs navigation for aiming the stop nail drilling operation.

2. The intramedullary nail navigation system according to claim 1, wherein, The relative attitude includes at least one of the following: The angle (α) between the center axis of the locking hole and the center axis of the guide. The ratio of the portion of the guide that falls into a predefined three-dimensional space to the volume of the guide.

3. The intramedullary nail navigation system according to claim 2, wherein, The included angle (α) is the projection angle formed by the projections of the drill bit's central axis and the locking hole's central axis onto a plane that includes or is parallel to the locking hole's central axis. The computing device is also configured to confirm whether the included angle (α) is within a predetermined range, wherein, When the included angle is ≥ 45 degrees and ≤ 135 degrees, the computing device determines that the operation to be performed is drilling for implanting a stop nail; When the included angle is less than 45 degrees or greater than 135 degrees, the computing device determines that the operation to be performed is drilling for implanting a locking pin.

4. The intramedullary nail navigation system according to claim 2, wherein, The predefined three-dimensional space includes a first space adjacent to and surrounding the distal locking hole (10), a second space adjacent to and surrounding the proximal locking hole (12), and a third space adjacent to but not surrounding the locking holes (10; 12), wherein the first space, the second space, and the third space do not overlap with each other, and The computing device is also configured to confirm whether the volume ratio of the portion of the guide that falls into the first space, the second space, or the third space relative to the volume of the guide is within a predetermined range, wherein, When the volume ratio of the guide falling into the first space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for inserting a locking pin into the distal locking hole. When the volume ratio of the guide falling into the second space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for inserting a locking pin into the proximal locking hole; If the volume ratio of the guide falling into the third space is ≥ 1 / 2, the computing device determines that the operation to be performed is drilling for implanting the stop pin.

5. The intramedullary nail navigation system according to claim 3 or 4, wherein, The relative attitude also includes the distance between the center axis of the locking hole and the center axis of the guide, and The computing device is also configured to compare the distance between the guide center axis and the locking hole center axis of each locking hole before confirming whether the included angle (α) and / or the volume ratio is within a predetermined range, in order to determine whether the operation to be performed is for the distal locking hole (10) or the proximal locking hole (12).

6. The intramedullary nail navigation system according to claim 1, wherein, The computing device is also configured to: In navigation for aiming at locking pin drill holes, the computing device determines whether the drill bit can enter the locking hole (10) to be aimed at by traveling along its axial direction based on the relative attitude. Within the range of 12), the drill bit is determined to be within the target locking hole (10); 12) Is it aligned? as well as In navigation for aiming operations of blocking nail drilling, the computing device determines whether the drill is aimed at the outside of the intramedullary nail based on the relative attitude.

7. The intramedullary nail navigation system according to claim 6, wherein, The tracking control unit (120) is configured to create a 3D model of the drill string (20') and a 3D model of the intramedullary nail (1'), the intramedullary nail 3D model including a 3D model of the locking hole (10'), and The computing device is also configured to determine, by means of the 3D model of the drill bit and the 3D model of the locking hole, whether the drill bit is aligned with the locking hole to be aimed, and to send a command to the display device to display the aligned or unaligned state.

8. The intramedullary nail navigation system according to claim 7, wherein, The computing device is also configured such that when the computing device calculates that the cut profile obtained by the intersection of the tangent plane of the drill bit 3D model and the locking hole 3D model is within the range of the end face profile of the locking hole 3D model, the computing device determines that the drill bit is aligned with the locking hole to be aimed.

9. The intramedullary nail navigation system according to claim 6, wherein, The computing device is also configured to calculate the distance between the outer periphery of the drill bit used for blocking nail drilling and the outer periphery of the adjacent intramedullary nail, and to determine whether the distance is less than a predetermined threshold and send a command to the display device for corresponding display, wherein the predetermined threshold is a distance value of 1 mm. If the distance is less than the predetermined threshold, the computing device identifies the target drilling location where the stop pin can be inserted.

10. The intramedullary nail navigation system according to claim 1, wherein, The display device is configured to display, in response to instructions from the computing device, a locking pin drilling aiming operation or a blocking pin drilling aiming operation, to indicate whether the drill bit is misaligned or aligned with the locking hole to be aimed, or to indicate whether the drill bit is aimed at the outside of the intramedullary nail.

11. The intramedullary nail navigation system according to any one of claims 1 to 9, wherein, The sensing device includes at least one electromagnetic sensor (30a) disposed within the intramedullary nail and at least one magnetic field generator (30b) disposed in the guide (20) for the drill bit.

12. The intramedullary nail navigation system according to claim 10, wherein, It is also provided with a connection line for connecting to an electromagnetic sensor (30a). The electromagnetic sensor (30a) is connected to an interface control unit (140) via the connection line. The connection line includes a connection line interface and a storage chip disposed in the connection line interface. Instrument information related to the type and specifications of the intramedullary nail can be written into and stored in the storage chip. Thus, when the interface control unit is connected to the tracking control unit (120), the tracking control unit can automatically read the current instrument information and send it to the computing device (130) for display on the display device.

13. A method for performing navigation using an intramedullary nail navigation system (100) according to any one of claims 1 to 12, the method comprising: a) Tracking step, in which the relative attitude of the drill bit and the intramedullary nail is tracked by the sensing device (110) of the electromagnetic tracking device, and the tracking control unit (120) of the electromagnetic tracking device is used to establish a 3D model (20') of the drill bit and a 3D model (1') of the intramedullary nail, wherein the 3D model of the intramedullary nail includes a 3D model of the locking hole (10', 12'). and b) The step of automatically determining the operation intention, wherein a computing device determines, based on the relative posture, whether the operation to be performed is drilling for inserting a locking pin or drilling for inserting a blocking pin. In the case where the operation to be performed is drilling for implanting a locking nail, the intramedullary nail navigation system performs navigation for aiming the locking nail drilling operation; When the operation to be performed is drilling for the implantation of a stop nail, the intramedullary nail navigation system performs navigation for aiming the stop nail drilling operation.

14. The method according to claim 13, wherein, The relative attitude includes at least one of the following: the angle (α) between the central axis of the locking hole and the central axis of the guide; the ratio of the volume of the portion of the guide falling into a predefined three-dimensional space to the volume of the guide. The step of automatically determining the operational intent includes confirming whether the included angle (α) and / or the volume ratio are within a predetermined range.

15. The method according to claim 14, wherein, The included angle (α) is the projection angle formed by the projection of the drill bit center axis and the locking hole center axis in a plane that includes or is parallel to the locking hole center axis. When the included angle is ≥ 45 degrees and ≤ 135 degrees, the computing device determines that the operation to be performed is drilling for implanting a stop pin. When the included angle is less than 45 degrees or greater than 135 degrees, the computing device determines that the operation to be performed is drilling a hole for inserting a locking pin. The predefined three-dimensional space includes a first space established adjacent to and surrounding the distal locking hole (10), a second space established adjacent to and surrounding the proximal locking hole (12), and a space adjacent to the locking hole (10); 12) However, a third space is established that does not surround the locking hole, wherein the first space, the second space, and the third space do not overlap with each other. When the volume ratio of the guide falling into the first space is ≥1 / 2, the computing device determines that the operation to be performed is drilling for inserting a locking pin in the distal locking hole; when the volume ratio of the guide falling into the second space is ≥1 / 2, the computing device determines that the operation to be performed is drilling for inserting a locking pin in the proximal locking hole; when the volume ratio of the guide falling into the third space is ≥1 / 2, the computing device determines that the operation to be performed is drilling for inserting a blocking pin.

16. The method of claim 14, wherein, The relative attitude also includes the distance between the center axis of the locking hole and the center axis of the guide, and The computing device is also configured to compare the distance between the guide center axis and the locking hole center axis of each locking hole before confirming whether the included angle (α) and / or the volume ratio is within a predetermined range, in order to determine whether the operation to be performed is for the distal locking hole (10) or the proximal locking hole (12).

17. The method according to any one of claims 13 to 16, wherein, The method is also used to aim the drill bit at the locking holes (10, 12) of the intramedullary nail (1) during locking nail drilling navigation in the intramedullary nail navigation system, and the method further includes the following steps: c) A determination step, in which a computing device (130) determines, based on the relative attitude, whether the drill bit can enter the range of the target locking hole (10; 12) by traveling along its axial direction; and d) Display step: In the display step, the locking pin drilling aiming operation is displayed using a display device to show whether the drill bit and the locking hole to be aimed are in a misaligned or aligned state. In the determination step, the computing device uses the 3D model of the drill bit and the 3D model of the locking hole to determine whether the drill bit is aligned with the locking hole to be aimed, and sends a command to the display device to display the aligned or unaligned state.

18. The method of claim 17, further comprising: Obtain the first spatial transformation from the drill string 3D model (20') to the intramedullary nail 3D model (1'), and obtain the second spatial transformation from the intramedullary nail 3D model (1') to the drill string 3D model (20').

19. The method of claim 18, further comprising: Based on the position and orientation of the proximal and distal tangential planes of the locking hole relative to the intramedullary nail 3D model, and based on the first spatial transformation and the second spatial transformation, the proximal tangential plane transformation from the drill bit 3D model to the locking hole and the distal tangential plane transformation from the drill bit 3D model to the locking hole are obtained.

20. The method of claim 19, further comprising: Obtain the spatial transformation from the near and far tangent planes of the locking hole to the 3D model of the drill string; The 3D model of the drill bit is extended to obtain a virtual drill bit extension model outline, which intersects with the near-side tangent plane and the far-side tangent plane of the locking hole, respectively, and generates a near-side intersection outline and a far-side intersection outline. Obtain the corresponding spatial transformations of the proximal and distal intersecting contour lines to the proximal and distal tangent planes of the locking hole; and Determine whether the proximal intersecting contour lines and the distal intersecting contour lines are respectively located within the proximal end face contour and the distal end face contour of the locking hole.

21. The method according to any one of claims 13 to 16, wherein, The method further includes operating the intramedullary nail navigation system to aim the blocking nail at the outer side of the intramedullary nail during blocking nail drilling navigation. The determination step further includes using a computing device to calculate the distance between the outer periphery of the drill bit used for drilling the blocking nail and the outer periphery of the adjacent intramedullary nail. The computing device is also used to determine whether the distance is less than a predetermined threshold, wherein the predetermined threshold is a distance value of 1 mm. Specifically, if the distance is less than the predetermined threshold, a computing device confirms the target drilling location suitable for inserting the stop pin and sends a command to the display device for corresponding display. The display step also includes displaying the aiming operation of the stop nail drilling using a display device in accordance with the instruction.

Images