Bone holder for cheekbone fracture reduction and robot-assisted cheekbone fracture reduction method

Abstract

The invention relates to the technical field of medical instruments, in particular to a bone holder for cheekbone fracture reduction and a robot-assisted cheekbone fracture reduction method. The bone holder for reduction of the fracture of the cheekbone provided by the invention comprises a fixed end which is provided with at least one fixing hole and is used for being rigidly connected with a bone block through a fixing piece; one end of the connecting rod is fixedly connected with the fixed end, and the other end of the connecting rod is provided with a connecting structure used for being detachably connected with the tail end of the mechanical arm; and the plurality of registration points are distributed on the surfaces of the fixed end and the connecting rod and are used for performing intraoperative registration through a registration tool. According to the bone holder, the application scene is widened, a stable and reliable connection mode is provided, and the foundation of high-precision registration is laid.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a bone holder for zygomatic bone fracture reduction and a robot-assisted method for zygomatic bone fracture reduction. Background Technology

[0002] Robot-assisted surgery has been widely used in orthopedics, neurosurgery, and other fields, demonstrating significant advantages in improving surgical precision and reducing surgeon fatigue. In maxillofacial surgery, especially in procedures involving complex bone repositioning such as zygomatic fracture reduction and orthognathic surgery, extremely high precision in the spatial positioning of bone fragments is required. Existing technologies have explored the application of robotic systems in these types of surgeries.

[0003] Currently, publicly available end effector bone-holding tools for maxillofacial surgical robots mainly suffer from the following problems: First, their application scenarios are limited. For example, the end effector used in orthognathic surgery is usually a "fork" structure that connects to the patient's occlusal plate. This structure is designed specifically for Le fort I maxillary surgery and cannot be adapted to facial bones such as the zygomatic bone that do not involve the dentition, making it difficult to build a universal bone block positioning system. Second, the fixation methods are limited. The aforementioned "fork" type tool relies on a complete and stable dentition, making it unsuitable for patients with loose, missing, or edentulous teeth. Furthermore, it usually requires personalized fabrication before surgery, resulting in a long cycle and high cost. Third, the registration accuracy depends on anatomical landmarks. Existing methods often use anatomical landmarks near the bone block for non-invasive registration during surgery. However, the repeatability of anatomical landmarks is poor, and they are easily interfered with by soft tissue, leading to insufficient registration accuracy and stability, making it difficult to meet the high-precision autonomous positioning requirements of robots.

[0004] Therefore, there is an urgent need for a bone holder that can adapt to bone blocks in non-dental areas such as the cheekbone, provide stable rigid connections, and achieve high-precision intraoperative registration, so as to support the robotic system to achieve precise and autonomous bone block repositioning operations in a wider range of maxillofacial surgeries. Summary of the Invention

[0005] The purpose of this invention is to provide a bone holder for zygomatic fracture reduction and a robot-assisted method for zygomatic fracture reduction, so as to solve the technical problems of limited application scenarios, uncommon fixation methods and insufficient registration accuracy of existing bone holders.

[0006] In a first aspect, the present invention provides a bone holder for reducing a zygomatic bone fracture, comprising: The fixed end has at least one fixing hole for rigid connection with the bone block via a fixing element; A connecting rod, one end of which is fixedly connected to the fixed end, and the other end is provided with a connecting structure for detachable connection to the end of the robotic arm; Multiple registration points are distributed on the surfaces of the fixed end and the connecting rod for intraoperative registration using a registration tool.

[0007] In an optional embodiment, the middle section of the connecting rod is provided with a rectangular expansion area, and the rectangular expansion area is provided with columnar protrusions; The two sides of the rectangular extension area are inclined toward the columnar protrusion, so that the bone holder forms a multi-layered structure with different heights; The registration points are provided on both the rectangular extension area and the columnar protrusion.

[0008] In an optional embodiment, the angle between the fixed end and the connecting rod is 110°±10°, and the angle between the connecting structure at the end of the connecting rod and the connecting rod is 130°±10°.

[0009] In an optional implementation, the registration point is a hemispherical depression whose diameter matches the hemispherical structure at the end of the registration probe.

[0010] In an optional embodiment, the width of the fixed end is 1.3-1.6 cm; The length of the fixed end is 0.9cm-1.1cm.

[0011] In an optional embodiment, the fixing end is provided with three fixing holes, the diameter of which is 1.8-2.2mm, for fixing to the zygomatic bone block with titanium screws.

[0012] Secondly, the present invention provides a method for robot-assisted reduction of a zygomatic bone fracture, performed as described in any of the foregoing embodiments, comprising the following steps: Positioning markers were installed on the patient's head to complete the registration of the patient's coordinate system with the navigation system; Markers are installed at the end of the robotic arm to complete the registration of the robotic arm's coordinate system with the navigation system; The bone holder is attached to the target bone block using a fixation device; The registration probe was used to collect the registration points on the bone holder, and the bone holder and bone block were bound together as a composite. Perform osteotomy; Connect the composite to the end effector of the robotic arm; The robotic arm is controlled to move the bone block to a preset position and fix it in place.

[0013] In an optional implementation, the end of the registration probe is hemispherical, matching the registration point of the hemispherical recess on the bone holder, and the three-dimensional coordinates of the registration point are acquired through contact.

[0014] In an optional embodiment, the fixation element is a titanium nail, which rigidly connects the bone holder to the bone block through a fixation hole on the fixation end.

[0015] In an optional implementation, the navigation system employs a visible light-based active stereo vision camera, which can display real-time information about the patient, instruments, and environment in the surgical scene.

[0016] Compared with the prior art, the technical advantages of the bone holder and robot-assisted method for zygomatic bone fracture reduction provided by the present invention are as follows: The bone holder for zygomatic bone fracture reduction provided by the present invention includes: a fixed end having at least one fixed hole for rigid connection with the bone block via a fixation element; a connecting rod having one end fixedly connected to the fixed end and the other end having a connecting structure for detachable connection with the end of a robotic arm; and multiple registration points distributed on the surfaces of the fixed end and the connecting rod for intraoperative registration using a registration tool.

[0017] Compared with existing technologies, it has the following advantages: 1. Expanded application scenarios: By setting a fixed end with a fixing hole, the bone holder can be rigidly connected to bone blocks in non-dental areas such as the zygomatic bone through fixing components (such as titanium screws), eliminating the dependence on the integrity of the patient's dentition. It can adapt to bone blocks of different positions and shapes in various maxillofacial surgical procedures, providing a hardware foundation for realizing a universal bone block positioning system.

[0018] 2. It provides a stable and reliable connection method: the rigid connection between the fixed end and the bone block is more stable than the method that relies on dentition occlusion or soft tissue fixation. It can withstand the force and torque during the operation of the robotic arm, ensuring the position controllability of the bone block during the movement process, while avoiding the cumbersome process and cost of making a personalized occlusal plate before surgery.

[0019] 3. It laid the foundation for high-precision registration: By directly setting multiple dedicated registration points on the surface of the bone holder, a stable, repeatable, and spatially well-distributed set of external feature points was provided for intraoperative registration. This replaced the registration method that relied on volatile anatomical landmarks, fundamentally creating conditions for improving the registration accuracy of the bone block-bone holder complex and providing a reliable spatial reference for subsequent high-precision autonomous robot positioning.

[0020] The robot-assisted reduction method for zygomatic bone fracture provided by the present invention uses the bone holder for zygomatic bone fracture reduction as described above. Therefore, the technical advantages and effects achieved include those of the bone holder for zygomatic bone fracture reduction, which will not be elaborated here.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a frontal schematic diagram of the bone holder provided in an embodiment of the present invention; Figure 2 This is a side view of the bone holder provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the bone holder structure provided in an embodiment of the present invention; Figure 4 A flowchart of a robot-assisted zygomatic bone fracture reduction method provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the bone holder registration provided in an embodiment of the present invention; Figure 6 A schematic diagram illustrating the shape and structure of the robotic arm end effector and its connection method with the bone holder, provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of a robot-assisted zygomatic bone fracture reduction experiment using a bone holder on a zygomatic bone reduction model, as provided in an embodiment of the present invention.

[0024] Icons: 1-Bone holder; 2-Fixed end; 3-Fixed hole; 4-Connecting rod; 5-Connecting structure; 6-Regulation point; 7-Rectangular extension area; 8-Columnar protrusion; 9-Curved surface marker; 10-Connector. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0029] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0030] The specific structure is as follows: Figures 1 to 7 As shown.

[0031] This embodiment provides a bone holder 1 for zygomatic bone fracture reduction. The bone holder 1 is made entirely of medical-grade materials that can withstand high-temperature and high-pressure sterilization, such as medical-grade aluminum alloy or medical-grade stainless steel that meets biocompatibility requirements. The bone holder 1 includes a fixing end 2, a connecting rod 4, and multiple registration points 6. The fixing end 2 is a plate-like structure for direct connection with the bone fragment. Its dimensions are optimized for the surface anatomy of maxillofacial bone fragments such as the zygomatic bone, with a length L of approximately 1.0 cm (adjustable within the range of 0.9-1.1 cm) and a width W of approximately 1.5 cm (adjustable within the range of 1.3-1.6 cm). This size design can minimize obstruction of the surgical field and avoid interference with the placement of subsequent internal fixation devices such as bone plates while ensuring sufficient fixation strength and stability. At least one fixing hole 3 is provided on the fixing end 2. As a preferred solution that provides optimal connection rigidity and stability, the fixing end 2 has three fixing holes 3 with a diameter of 2 mm (adjustable within the range of 1.8-2.2 mm), which are distributed in a triangular pattern. These three fixation holes 3 are used to insert medical titanium screws, thereby firmly fixing the bone holder 1 to the surface of the zygomatic bone block in a three-point rigid support manner. This rigid connection method provides extremely strong connection stability and is flexible in terms of installation position. During the operation, the thicker and stronger areas of bone can be selected for fixation according to the shape of the bone block and the bone quality, effectively avoiding areas with thin bone.

[0032] The connecting rod 4 is a one-piece rod-shaped structure. One end is fixedly connected to the fixed end 2, and the included angle α between them is designed to be 110° (with a manufacturing and adjustment tolerance of ±10° allowed). The other end of the connecting rod 4 is provided with a connecting structure 5, which in this embodiment is a connecting block, used to form a quick-release detachable connection with the end effector of the robotic arm (such as a connector 10 with curved surface markings 9) through a T-screw. The included angle β between the end portion of the connecting rod 4 (i.e., the section where the connecting structure 5 is located) and the main body of the connecting rod 4 is designed to be 130° (with a manufacturing and adjustment tolerance of ±10° allowed). These two specific angles are the result of optimization after ergonomic analysis and clinical surgical simulation (considering the patient's supine position, surgical approach, and robotic arm workspace). This design ensures that during the operation, the bone holder 1 connected to the robotic arm and the robotic arm body have sufficient operating space when moving, effectively avoiding interference or collision with the patient's body, which is a key design to ensure smooth surgical procedures and patient safety.

[0033] The multiple registration points 6 are dedicated feature points distributed on the surface of the bone holder 1 for intraoperative spatial positioning. To obtain a highly unique point cloud set in space to ensure registration accuracy, the bone holder 1 is designed in three dimensions. Specifically, a rectangular extension area 7 is provided in the middle section of the connecting rod 4, and a columnar protrusion 8 is further provided on the rectangular extension area 7. The two sides of the rectangular extension area 7 are inclined towards the columnar protrusion 8, which creates significant height differences in the four regions of the bone holder 1: the fixed end 2, other parts of the connecting rod 4, the rectangular extension area 7, and the columnar protrusion 8, forming a structure with clear three-dimensional features. The registration points 6 are distributed on the surface of these regions at different heights.

[0034] In a preferred embodiment, the registration point 6 is a machined hemispherical recess with a diameter of approximately 2 mm. This shape design is intended to form a precise "ball-and-socket" match with the hemispherical end of the matching registration tool—the probe. This contact method is stable, repeatable, and minimizes measurement errors caused by probe slippage, making it an effective means of achieving high-precision contact registration. In actual operation, the doctor uses the probe to stably contact each hemispherical recess sequentially, allowing the navigation system to acquire accurate three-dimensional coordinates.

[0035] It is understandable that the specific form and detection method of registration point 6 are not limited to this. For example, in an alternative, registration point 6 could also be a cylindrical protrusion protruding from the surface of the bone holder 1, with a highly reflective coating at its top. In this case, the matching registration tool can use a non-contact probe with laser scanning or optical scanning capabilities to obtain coordinates by scanning these reflective marks. Similarly, the three-dimensional structure of the connecting rod 4 can also take other forms, as long as it enables the registration points 6 to be non-coplanarly distributed in space, enhancing the uniqueness of the point cloud set.

[0036] The method for robot-assisted reduction of zygomatic bone fracture using the bone holder 1 in this embodiment includes the following steps: installing positioning markers on the patient's head to complete the registration of the patient's coordinate system with the navigation system; installing markers at the end of the robotic arm to complete the registration of the robotic arm's coordinate system with the navigation system; mounting the bone holder 1 onto the target bone block using a fixing device; using a registration probe to collect the registration points 6 on the bone holder 1, binding the bone holder 1 and the bone block into a composite; performing osteotomy; connecting the composite to the end of the robotic arm; and controlling the robotic arm to move the bone block to a preset position and fix it.

[0037] The registration probe has a hemispherical tip that matches the registration point 6 in the hemispherical recess on the bone holder 1, acquiring the three-dimensional coordinates of the registration point 6 through contact. The fixation element is a titanium screw, which rigidly connects the bone holder 1 to the bone block through the fixation hole 3 on the fixation end 2. The navigation system uses a visible light-based active stereo vision camera, capable of displaying real-time information about the patient, instruments, and environment in the surgical scene.

[0038] Specifically, S1: System Registration. A reference frame is installed above the patient's head, and markers are attached to the end effector of the robotic arm. The visible light-based active stereo vision navigation system is activated, sequentially registering the patient's coordinate system, robotic arm coordinate system, and navigation system coordinate system to establish a unified coordinate mapping relationship. This system can display real-time information about the patient, instruments, and environment in the surgical scene, enhancing surgical safety.

[0039] S2: Install bone holder 1. Select a suitable position on the target zygomatic bone block and use titanium screws to securely install bone holder 1 through the fixing hole 3 of the fixing end 2.

[0040] S3: Composite Registration. A probe is used to contact each registration point 6 on the bone holder 1. The navigation system collects point cloud data and uses an algorithm (such as the ICP algorithm) to precisely match it with the virtual point cloud in the preoperative 3D model, completing the "registration" of the bone holder 1. Since the bone holder 1 is rigidly connected to the bone block, the two are now bound together as a "bone block-bone holder 1 composite".

[0041] S4: Osteotomy and Robotic Repositioning. After osteotomy, the connecting structure 5 of the bone holder 1 is quickly connected to the end effector of the robotic arm. As an autonomous surgical robot, the robotic arm automatically and precisely moves and positions the composite to the preset anatomical location according to the pre-planned path.

[0042] S5: Final Fixation and Removal. After fixing the bone block at the target location, remove the bone holder 1.

[0043] The technical advantages of this embodiment are as follows: a universal and rigid connection with the bone block is achieved through the fixed end 2 and titanium screws; a safe surgical space is ensured through the specific angle design of the connecting rod 4; and stable, high-precision spatial features are provided for the navigation system through dedicated registration points 6 distributed on the three-dimensional structure. These features work together to ultimately support the robot system in achieving sub-millimeter-level bone block positioning accuracy.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bone holder for reducing a zygomatic bone fracture, characterized in that, include: The fixed end (2) is provided with at least one fixed hole (3) for rigid connection with the bone block by means of a fastener; The connecting rod (4) has one end fixedly connected to the fixed end (2) and the other end is provided with a connecting structure (5) for detachable connection with the end of the robotic arm; Multiple registration points (6) are distributed on the surfaces of the fixed end (2) and the connecting rod (4) for intraoperative registration using a registration tool.

2. The bone holder for zygomatic bone fracture reduction according to claim 1, characterized in that, The middle section of the connecting rod (4) is provided with a rectangular expansion area (7), and the rectangular expansion area (7) is provided with a columnar protrusion (8). The rectangular extension area (7) is inclined on both sides toward the columnar protrusion (8) so that the bone holder (1) forms a multi-layered structure with different heights; The registration point (6) is provided on both the rectangular extension area (7) and the columnar protrusion (8).

3. The bone holder for zygomatic bone fracture reduction according to claim 1, characterized in that, The angle between the fixed end (2) and the connecting rod (4) is 110°±10°, and the angle between the connecting structure (5) at the end of the connecting rod (4) and the connecting rod (4) is 130°±10°.

4. The bone holder for zygomatic bone fracture reduction according to claim 1, characterized in that, The registration point (6) is a hemispherical depression whose diameter matches the hemispherical structure at the end of the registration probe.

5. The bone holder for zygomatic bone fracture reduction according to claim 1, characterized in that, The width of the fixed end (2) is 1.3-1.6cm; The length of the fixed end (2) is 0.9cm-1.1cm.

6. The bone holder for zygomatic bone fracture reduction according to claim 1, characterized in that, The fixed end (2) is provided with three fixed holes (3), the diameter of which is 1.8-2.2 mm, for fixing to the zygomatic bone block by means of titanium nails.

7. A method for robot-assisted reduction of zygomatic bone fracture, characterized in that, The procedure is performed using a bone holder for zygomatic fracture reduction as described in any one of claims 1 to 6, including the following steps: Positioning markers were installed on the patient's head to complete the registration of the patient's coordinate system with the navigation system; Markers are installed at the end of the robotic arm to complete the registration of the robotic arm's coordinate system with the navigation system; The bone holder (1) is installed on the target bone block using a fixation device; The registration point (6) on the bone holder (1) was collected using a registration probe, and the bone holder (1) was bound to the bone block as a composite. Perform osteotomy; Connect the composite to the end effector of the robotic arm; The robotic arm is controlled to move the bone block to a preset position and fix it in place.

8. The method for robot-assisted reduction of zygomatic bone fracture according to claim 7, characterized in that, The end of the registration probe is hemispherical and matches the registration point (6) of the hemispherical depression on the bone holder (1). The three-dimensional coordinates of the registration point (6) are acquired by contact.

9. The method for robot-assisted reduction of zygomatic bone fracture according to claim 7, characterized in that, The fixation element is a titanium nail, and the bone holder (1) is rigidly connected to the bone block through the fixation hole (3) on the fixation end (2).

10. The method for robot-assisted reduction of zygomatic bone fracture according to claim 7, characterized in that, The navigation system uses an active stereo vision camera based on visible light, which can display patient, instrument and environmental information in the surgical scene in real time.

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