Affected side pelvis holding device of pelvic fracture reduction robot

Abstract

The invention relates to an affected-side pelvic holding device of a pelvic fracture reduction robot. The affected-side pelvic holding device comprises a reduction force detection unit and an affected-side screw holding branched chain. The reset force detection unit is connected with the tail end of the robot through a six-dimensional force sensor, and vector parameters of reset force are monitored and fed back in real time. The three groups of affected side screw holding branched chains are distributed in an equilateral triangle shape, and the influence of screw deformation on reset precision is remarkably reduced through space coupling constraint among the branched chains. The affected side screw holding branch chain comprises a lockable universal spherical hinge assembly, a telescopic rod assembly and a rotary adjusting assembly, and has multiple degrees of freedom; the tail ends of the three branched chains can be quickly positioned and connected to screws on the affected side to cooperatively hold the pelvis on the affected side, and a rigid connection structure is formed after the three branched chains are locked; through the arrangement, the effects of real-time feedback of reset force, compact structure, high rigidity, large holding force and the like can be achieved, the device can adapt to any posture of an affected-side screw, the flexibility is high, operation is convenient and fast, and the safety and efficiency of affected-side pelvis holding operation are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an affected-side pelvic gripping device of a pelvic fracture reduction robot. Background Art

[0002] Pelvic fractures are common and serious clinical traumas, usually caused by high-energy injuries (such as traffic accidents and falls from heights). Due to the complex anatomical structure of the pelvis and its proximity to important blood vessels, nerves, and organs, the accuracy of its reduction directly affects the patient's postoperative functional recovery and the incidence of complications. Traditional open reduction surgery relies on the surgeon's experience and manual operation, and has problems such as large trauma, low reduction accuracy, and frequent intraoperative radiation exposure. These defects not only prolong the operation time, but may also lead to poor postoperative recovery and increase the risk of complications.

[0003] In recent years, orthopedic surgical robotics has been increasingly applied to pelvic fracture reduction. Through robotic arm-assisted positioning and motion control, these technologies have significantly improved the repeatability of reduction path planning. Chinese invention patent publication CN118634034A discloses a three-axis parallel reduction mechanism for closed pelvic fracture reduction, specifically a parallel reduction robot. Through the specific configuration of its components, it achieves a compact structure, high precision, high load capacity, high flexibility, and a large workspace. Its center of motion is a virtual point in space, and its position can be adjusted according to the patient and fracture type, making it easy to operate. However, since the ipsilateral screw gripping device is intended to increase the degree of freedom (by achieving three-dimensional spatial movement through a three-axis motion device), the ipsilateral gripping device only needs to move within the plane defined by the gripping rod. However, this configuration requires further improvement in terms of high-load gripping, degree of freedom configuration, and spatial adaptability. Specifically, for this type of robot, gripping and stabilizing the ipsilateral pelvis remains one of the core challenges of robot-assisted reduction systems. While existing ipsilateral pelvic gripping devices can provide high-load gripping, their degree of freedom configuration and spatial adaptability are insufficient. The fragments of pelvic fractures often present asymmetric postures, and existing single-axis adjustment or limited freedom gripping ends make it difficult to achieve adaptive locking after multi-angle screw implantation. This leads to time-consuming repeated adjustments during surgery and may cause structural instability due to mechanical coupling. At the same time, during the dynamic reduction process, the lack of real-time feedback and adaptive adjustment capabilities of multi-dimensional mechanics makes it difficult to maintain a stable gripping force. In addition, the existing gripping devices are bulky, which limits the flexibility of intraoperative operations, affects the clarity of the surgical field and the planning of multi-angle reduction paths. At the same time, the lack of soft tissue protection mechanisms increases the risk of vascular and nerve damage, making it difficult to meet the needs of minimally invasive surgery.

[0004] Therefore, there is an urgent need to design a new ipsilateral pelvic gripping device with high rigidity, strong adaptability and real-time reset force feedback. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of existing technologies by providing an ipsilateral pelvic gripping device for a pelvic fracture reduction robot. This device enhances the stability and safety of robot-assisted reduction, providing core instrument support for closed pelvic fracture reduction. By achieving greater degrees of freedom and flexibility, the device can effectively adapt to various fracture positions in complex anatomical environments, ensuring efficient and safe surgical procedures and ultimately improving intraoperative reduction outcomes.

[0006] The invention discloses an affected-side pelvic holding device of a pelvic fracture reduction robot, comprising a reduction force detection unit and an affected-side screw holding branch chain.

[0007] The reset force detection unit includes a six-dimensional force sensor, a connecting shaft, and a connecting plate. The top of the six-dimensional force sensor is connected to the pelvic fracture reduction robot actuator, and the bottom is fixedly connected to the connecting shaft. The reset force detection unit is used to monitor and provide feedback on the reset force vector parameters in real time. Three through-holes are formed on the connecting plate to form a branch connection. The connecting line of the three branch connection axes forms an equilateral triangle. A locking nut is used to pre-tighten the branch chain held by the screw on the affected side, forming a three-point force distribution structure.

[0008] The affected-side screw holding branch chains are provided with three groups, each group including a universal ball joint assembly, a telescopic rod assembly and a rotation adjustment assembly.

[0009] The universal ball joint assembly is provided with an end cover, and the outer circumference of the end cover can be fixedly connected to the inner circumference of the branch joint.

[0010] The telescopic rod assembly includes an inner telescopic rod and an outer telescopic rod. The inner telescopic rod is connected to the universal ball joint assembly. The outer telescopic rod is wrapped around the outside of the inner telescopic rod and can be extended or shortened along the axis of the inner telescopic rod. The ratio of the length of the telescopic rod assembly when extended to the longest to the length of the axis connecting line of adjacent branch joints is (100-120):(65-90).

[0011] One end of the rotation adjustment component is connected to the telescopic rod component, and the other end is connected to the holding screw in a rotatable manner, and the holding screw is connected to the affected side pelvis.

[0012] The ipsilateral pelvic gripping device is arranged above the femur along the vertical axis of the human body, with its axis aligning with the traction direction of the pelvic fracture. The reduction force detection unit, integrated with a six-dimensional force sensor, is mounted on the end of the pelvic fracture reduction robot for real-time monitoring and feedback of the reduction force vector parameters. The ipsilateral screw gripping branch is mounted on the end of the reduction force detection unit. During the screw positioning and gripping phase, each ipsilateral screw gripping branch has multiple degrees of freedom adjustment capabilities, enabling rapid screw positioning. During the locking phase, it forms a rigid structure with the pelvis, significantly reducing the impact of screw deformation on reduction accuracy through spatial coupling constraints between the ipsilateral screw gripping branches.

[0013] Preferably, the ratio of the length of the telescopic rod assembly when it is retracted to the shortest length to the length of the axis connecting line of the adjacent branch interface is (42-60):(65-90).

[0014] Preferably, the reset force detection unit also includes a locking nut; the top end of the connecting shaft is a disc structure, and the bottom end is a screw with an external thread. The disc structure is fixedly connected to the bottom end of the six-dimensional force sensor through the top end, and a through hole is provided at the center of the connecting disk. The screw at the bottom end of the connecting shaft passes through the through hole and is tightened and unscrewed by a threaded connection with the locking nut provided at the bottom end of the connecting disk.

[0015] Preferably, the universal ball joint assembly is fixedly connected to the connecting plate, and the universal ball joint assembly is used to install the telescopic rod assembly and provide three degrees of rotational freedom. After the rotation adjustment assembly is fixed to the holding screw, the universal ball joint assembly can be locked and fixed; the telescopic rod assembly and the universal ball joint assembly are fixedly connected by a pin, and the telescopic rod assembly is used to provide telescopic displacement for the holding branch chain of the affected side screw; the rotation adjustment assembly is fixed to the end of the telescopic rod assembly, and is used to adjust the angle between the holding branch chain of the affected side screw and the holding screw.

[0016] The components of the affected-side screw holding branch chain cooperate to adjust the posture of the branch chain end so as to quickly and stably fix it to the affected-side holding screw.

[0017] Preferably, the universal ball joint assembly includes a ball joint seat, a locking ball bowl, an adjusting screw and a ball head in addition to the end cover. The ball joint seat is hollow, and the top end is fixedly connected to the end cover. A locking ball bowl and a ball head are provided inside the ball joint seat. The outer periphery of the locking ball bowl matches the inner wall of the ball joint seat. The lower part of the locking ball bowl is an inverted bowl-shaped structure. The inverted bowl-shaped structure is semi-enclosed on the upper part of the ball head. The ball head includes an upper spherical end and a lower straight rod end. The straight rod end passes through the bottom end of the ball joint seat. A screw thread is provided between the spherical end of the ball head and the bowl-shaped structure. There is a gap, and the spherical end of the ball head can form a three-degree-of-freedom ball pair under the covering of the bowl-shaped structure and the ball joint seat; a threaded through hole is opened at the top of the end cover, and the adjusting screw is threadedly connected with the internal thread of the threaded through hole through the external thread, and the bottom end of the adjusting screw can be abutted against the top of the locking ball bowl, and the locking ball bowl can be displaced downward by tightening the adjusting screw and the gap between the locking ball bowl and the spherical end of the ball head can be eliminated, and then the adjusting screw is continued to be tightened to press the locking ball bowl and the ball head, and the motion locking is achieved by the friction between the locking ball bowl and the ball head.

[0018] The ball head contacts the locking bowl to form a three-degree-of-freedom spherical pair, with the adjustment screw actively locking the degrees of freedom of the spherical pair. After being secured with the holding screw, rotating the adjustment screw inward compresses the locking bowl, and the friction between the locking bowl and the ball head achieves motion locking.

[0019] Preferably, the telescopic rod assembly also includes a threaded rod; the inner rod of the telescopic rod is a hollow structure, and an internal thread is provided on the circumference of the hollow inner wall, the threaded rod includes a threaded end and a clamping end, the threaded end is threadedly connected to the internal thread of the inner rod of the telescopic rod through an external thread to form a self-locking thread pair, the lead angle of the self-locking thread pair is smaller than the friction angle, so that the threaded connection between the inner rod of the telescopic rod and the threaded rod has a self-locking function (preventing unexpected displacement under axial load; the lead angle of the self-locking thread pair is smaller than the friction angle, and the axial-circumferential composite constraint is formed in combination with the limiting slide groove and the anti-rotation cylindrical surface).

[0020] The telescopic rod assembly uses a dual locking mechanism of axial self-locking and circumferential limiting to achieve seamless switching between "flexible adjustment-rigid fixation" during surgery, making the adjustment process convenient and efficient.

[0021] Preferably, the telescopic rod assembly further includes a limit screw, a threaded rod, a bearing, a retaining spring and an adjusting nut; the top end of the inner rod of the telescopic rod is fixedly connected to the straight rod end of the ball head (preferably fixedly connected by a pin), and the inner rod of the telescopic rod forms a ball pair connection with the universal ball joint assembly; a shoulder is provided on the clamping end of the threaded rod, the bearing is sleeved on the clamping end below the shoulder, and the retaining spring is provided on the clamping end below the bearing, and the retaining spring fixes the inner ring of the bearing to the clamping end of the threaded rod; the lowest end of the clamping end of the threaded rod is fixedly connected to the upper end of the adjusting nut, and an adjusting nut slot is provided in the center of the bottom end of the adjusting nut; The outer part of the rod and the threaded rod is sleeved with a telescopic rod outer rod, and the telescopic rod outer rod includes an outer rod body, a limiting groove and a rotating shaft; the outer rod body is a hollow structure, and the inner wall of the outer rod body is fixedly connected to the outer ring of the bearing, the groove center line of the limiting groove is parallel to the axial center line of the telescopic rod outer rod, and the limiting screw includes a screw part and a screw cover part, the width of the limiting groove is greater than the diameter of the screw part and smaller than the diameter of the screw cover part, the screw part passes through the limiting groove and is fixedly connected to the telescopic rod inner rod at the bottom, and the linear displacement of the telescopic rod inner rod relative to the telescopic rod outer rod along the axis of the telescopic rod assembly is realized by rotating the adjusting nut slot to form a moving pair.

[0022] Preferably, the telescopic rod assembly also includes a hexagonal boss, which is arranged at the top of the inner rod of the telescopic rod. The hexagonal boss is used to prevent the telescopic rod assembly from rotating along its own axis by holding the hexagonal boss when rotating the adjustment nut slot; the inner rod of the telescopic rod is fixedly connected to the ball head by a pin.

[0023] Preferably, a bearing groove is provided at the lower end of the inner wall of the outer rod body, and the outer rod of the telescopic rod is fixedly connected to the outer ring of the bearing through the bearing groove.

[0024] Preferably, the rotation adjustment assembly includes a rotation clamp, a first locking nut, a first elastic collet, a second locking nut and a second elastic collet; the rotation clamp is provided with a first through hole and a second through hole perpendicular to each other, and the ends of the first through hole and the second through hole both protrude from the rotation clamp to form a tube body, and are provided with an external thread, and the rotating shaft of the outer rod of the telescopic rod can pass through the first through hole and be socketed with the first elastic collet on the other side, and the first locking nut can be tightened to the outside of the first elastic collet to lock the first elastic collet and the end of the rotating shaft (when the nut is not tightened, the rotation clamp can rotate around the rotating shaft to form a rotating pair); the second through hole is used to insert one end of the holding screw on the affected side and sequentially sleeve the second elastic collet and the second locking nut on the outside of the holding screw on the affected side, and the second elastic collet is locked to the end of the holding screw on the affected side by tightening the second locking nut on the outside of the second elastic collet.

[0025] Preferably, the ipsilateral screw retaining chain is positioned above the operating table, close to the upper surface of the human body. This results in a short lever arm, minimizing the impact of deformation of the ipsilateral screw retaining chain and screw on the accuracy of pelvic fracture reduction. After the ipsilateral screw retaining chain is secured, the three ipsilateral screw retaining chains are mutually constrained. By tightening the first and second locking nuts, the ipsilateral screw retaining chain and the pelvis form a rigid structure, resulting in a simple structure, convenient operation, and stable pelvic fixation.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The device of the present invention provides three specifically designed ipsilateral screw-holding branches, and through the coordinated action of a specific universal ball joint assembly, telescopic rod assembly, and rotation adjustment assembly, achieves multi-degree-of-freedom flexible adjustment of the branch end position, adapting to the patient's complex fracture morphology and different holding screw positions, significantly improving operational flexibility. Furthermore, by specifically setting the length of the telescopic rod assembly and the adjustable distance between the three branches, a relatively appropriate relative lever arm (neither too short nor too long) is achieved. Due to the specific coordinated movement and locking structure of the locking ball bowl, adjustment screw, and ball head provided in the present invention, a relatively short relative lever arm will reduce the effectiveness of the coordination and lead to a decrease in the overall stiffness and stability of the device; while a relatively long relative lever arm will cause the telescopic rod assembly and the holding screw to be mutually constrained in their range of motion. This proportional setting can thus reduce the impact of deformation of the ipsilateral screw holding unit and screw on the accuracy of pelvic fracture reduction. Furthermore, this proportional setting enables the universal ball joint assembly, telescopic rod assembly, and rotation adjustment assembly to better achieve high-quality fixation of complex ipsilateral fracture morphology and different holding screw positions within their range of motion.

[0028] 2. The present invention forms a rigid connection structure with the pelvis after locking the three branches, and combines the self-locking thread design and high stability characteristics of the specially set telescopic rod assembly to provide a strong holding force, ensure the stable fixation of the affected pelvis during the reduction process, and reduce reduction deviation. At the same time, the three branches are coordinated with the six-dimensional force sensor to achieve the real-time monitoring of the dynamic reduction force during the reduction process under the specific rigid holding of the present invention, and the real-time feedback of the reduction force data to avoid secondary damage caused by uneven or excessive force during the operation. In addition, by setting the telescopic rod assembly and the rotation adjustment assembly of each screw holding branch on the affected side specifically for self-locking and locking, and coordinating the high rigidity angle setting formed between the three branches, the small dynamic reduction force required for this type of operation can be fed back under the high rigidity holding condition, thereby providing quantitative protection for surgical safety.

[0029] 3. The present invention specifically sets up each component according to the unique requirements of the ipsilateral pelvis, so that it meets the movement and strength requirements of the ipsilateral pelvis during the operation; by adopting a modular design for each component, the component is compact and detachably connected, avoiding interference with the intraoperative field of view and path planning due to excessive size; at the same time, by setting up the specific connection method and matching method of each component (such as the matching of the locking ball bowl with the spherical end of the ball head and the adjusting screw, etc.), it effectively solves the problems of poor clamping adaptability, insufficient dynamic stability and limited operational flexibility in the prior art, and provides an ipsilateral pelvic gripping device for robot-assisted pelvic fracture reduction with real-time feedback of the reduction force, compact structure, good stability, large gripping force, high flexibility and convenient operation, which has significant clinical practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a side structural schematic diagram of the affected-side pelvic gripping device of the pelvic fracture reduction robot of the present invention.

[0031] Figure 2 This is a schematic top view of the structure of the affected-side pelvic gripping device of the pelvic fracture reduction robot of the present invention.

[0032] Figure 3 The figure is a schematic diagram of the exploded structure of a reset force detection unit according to an embodiment of the present invention.

[0033] Figure 4 This is a schematic structural diagram of the screw holding branch chain on the affected side according to one embodiment of the present invention.

[0034] Figure 5 The following are structural diagrams and cross-sectional diagrams of a universal ball joint assembly according to one embodiment of the present invention.

[0035] Figure 6 This is a schematic structural diagram of a telescopic rod assembly according to an embodiment of the present invention.

[0036] Figure 7 The figure is a schematic cross-sectional structural diagram of a telescopic rod assembly according to one embodiment of the present invention.

[0037] Figure 8 This is a schematic diagram of the exploded structure of a rotary adjustment assembly according to one embodiment of the present invention.

[0038] Wherein: 1-reset force detection unit; 2-universal ball joint assembly; 3-telescopic rod assembly; 4-rotation adjustment assembly; 5-holding screw; 6-pelvic fracture reduction robot; 7-affected pelvis; 8-six-dimensional force sensor; 9-connecting shaft; 10-connecting plate; 101-branch interface; 11-locking nut; 12-adjusting screw; 13-end cover; 14-locking ball bowl; 15-ball joint seat; 16-ball head; 161-ball end; 162-straight rod End; 17-hexagonal boss; 18-telescopic rod inner rod; 19-telescopic rod outer rod; 20-rotating axis; 21-adjusting nut; 22-adjusting nut slot; 23-limiting screw; 24-pin; 25-threaded rod; 26-bearing; 27-circlip; 28-rotating clamp; 281-first through hole; 282-second through hole; 29-second elastic collet; 30-second locking nut; 31-first elastic collet; 32-first locking nut. DETAILED DESCRIPTION

[0039] The present invention is described in detail below with reference to the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in this field based on these embodiments are all within the scope of protection of the present invention.

[0040] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, for the purposes of describing the embodiments of the present application herein.

[0041] In this application, when the terms "comprise" and or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and or combinations thereof. In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", "far", "near" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only relational words determined for the convenience of describing the structural relationships of the various components or elements of the present disclosure. They do not specifically refer to any component or element in the present disclosure and cannot be understood as limitations on the present disclosure. In the present disclosure, terms such as "fixed", "connected", "connected", "provided with", "equipped with" and the like should be understood in a broad sense, indicating that they can be fixedly connected, integrally connected or detachably connected; they can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present disclosure can be determined according to specific circumstances, and they cannot be understood as limitations on the present disclosure.

[0042] This example provides a pelvic gripping device for the affected side of a pelvic fracture reduction robot. Figures 1 to 8 As shown, the device includes a reset force detection unit 1 and an affected-side screw holding branch chain, and the affected-side screw holding branch chain includes a universal ball joint assembly 2, a telescopic rod assembly 3, and a rotation adjustment assembly 4.

[0043] like Figure 1 and Figure 2 As shown, the ipsilateral pelvic gripping device is arranged above the femur along the vertical axis of the human body, with its axis conforming to the traction direction of the pelvic fracture. The reduction force detection unit 1 integrates a six-dimensional force sensor and is installed at the end of the pelvic fracture reduction robot 6 for real-time monitoring and feedback of the reduction force vector parameters. The ipsilateral screw gripping branch chain is installed at the end of the reduction force detection unit 1 and is provided with three sets of ipsilateral screw gripping branches arranged in a triangular pattern. During the screw positioning and gripping stage, each ipsilateral screw gripping branch chain has multiple degrees of freedom adjustment functions, allowing for rapid screw positioning. During the locking stage, it forms a rigid structure with the pelvis, and the spatial coupling constraint between the ipsilateral screw gripping branches significantly reduces the impact of screw deformation on reduction accuracy.

[0044] like Figure 1 、 Figure 2 and Figure 3 As shown, the reset force detection unit includes a six-dimensional force sensor 8, a connecting shaft 9, a connecting disk 10, and a locking nut 11. One end of the six-dimensional force sensor 8 is connected to the robot actuator, and the other end is fixed with the connecting shaft 9; the connecting disk 10 is provided with three groups of branch chain interfaces 101 distributed at equal angles, and the locking nut 11 is used to pre-tighten and fix the branch chain of the affected side screw, forming a three-point force sharing structure.

[0045] like Figure 1 and Figure 4 As shown, the ipsilateral screw holding chain consists of a universal ball joint assembly 2, a telescopic rod assembly 3, and a rotation adjustment assembly 4. The universal ball joint assembly is fixed to a connecting plate 10, used to mount the telescopic rod assembly 3 and provide three degrees of rotational freedom. After being secured to the holding screw 5, the universal ball joint assembly 2 can be locked and fixed. The telescopic rod assembly 3 and the universal ball joint assembly 2 are fixedly connected by a pin and provide telescopic function for the ipsilateral screw holding chain. The rotation adjustment assembly 4 is fixed to the end of the telescopic rod assembly 3 and is used to adjust the angle between the ipsilateral screw holding chain and the holding screw 5. The various components of the ipsilateral screw holding chain work together to adjust the position of the branch end, allowing for quick and stable fixation to the ipsilateral holding screw 5.

[0046] The telescopic rod assembly of this embodiment is 108mm long when extended to its maximum length, and the length of the axis connecting the adjacent branch joints is 68mm (meeting the ratio requirement of (100-120):(65-90)). The telescopic rod assembly of this embodiment is 52mm long when retracted to its minimum length. During the implementation of this embodiment, an attempt was made to set the maximum length of the telescopic rod assembly to 132mm, while keeping other settings unchanged. It was found that during adjustment and holding, two adjacent telescopic rod assemblies frequently restrained each other, hindering the movement of the other telescopic rod assembly, making it impossible to properly set the desired holding position. A comparative test was also conducted with the maximum length of the telescopic rod assembly set to 66mm. It was found that after this setting, the large lateral rotation of the telescopic rod assembly affected the locking of the ball head component. Even after the ball head was locked with the locking ball bowl and adjustment screw, there was still a slight wobble. This is because the short telescopic rod assembly causes its lateral angle to be too large during some use, resulting in a slight decrease in the ball head locking effect. This further proves that the ratio relationship between the two settings set by the present invention is closely coordinated with other settings of the present invention.

[0047] like Figure 1 and Figure 5 As shown, the universal ball joint assembly includes a ball joint seat 15, a locking ball bowl 14, an adjusting screw 12, an end cover 13, and a ball head 16. The locking ball bowl 14 and the ball head 16 are arranged inside the ball joint seat 15. Figure 5 As shown, the outer periphery of the locking ball bowl matches the inner wall of the ball joint seat, and the lower part of the locking ball bowl is an inverted bowl-shaped structure. The inverted bowl-shaped structure is semi-enclosed on the upper part of the ball head. The ball head includes an upper spherical end 161 and a lower straight rod end 162. The ratio of the area of ​​the outer surface of the spherical surface in the spherical end 161 to the area of ​​the cross section at the connection between the spherical end 161 and the straight rod end 162 is (4.5 to 21):1 (for example, the value can be 8:1 in this embodiment). The straight rod end passes through the bottom end of the ball joint seat, and a gap is provided between the spherical end of the ball head and the bowl-shaped structure. The spherical end 161 of the ball head can form a three-degree-of-freedom ball pair under the covering of the bowl-shaped structure of the locking ball bowl 14 and the ball joint seat 15.

[0048] Active locking of the ball joint's degrees of freedom is achieved through the adjusting screw 12. The end cap 13 is fixedly connected to the ball joint seat 15. The adjusting screw 12 and the end cap 13 are connected through a central threaded hole. After being fixed to the holding screw 5, the adjusting screw 12 is rotated inward to press the locking ball bowl 14. The friction between the locking ball bowl 14 and the ball head 16 achieves motion locking.

[0049] like Figure 1 、 Figure 6 and Figure 7 As shown, the telescopic rod assembly includes an inner rod 18, an outer rod 19, a stop screw 23, a threaded rod 25, a bearing 26, a retaining ring 27, and an adjusting nut 21. The inner rod 18 is fixedly connected to the ball head 16 via a pin 24 (a pin is used in this embodiment), forming a ball-joint connection with the universal ball joint assembly 2. The hollow inner rod 18 is connected to the threaded rod 25 via threads and is circumferentially fixed by the stop screw 23. The bearing 26 is mounted on the lower end of the threaded rod 25 and is secured by a shoulder at the lower end of the threaded rod and the retaining ring 27. The upper end of the adjusting nut 21 is fixedly connected to the threaded rod 25, and the bottom end is provided with an adjusting nut slot 22. By rotating the adjusting nut slot 22, the telescopic rod inner rod 18 can move up and down relative to the telescopic rod outer rod 19 along the axis of the telescopic rod assembly, forming a moving pair; the upper end of the telescopic rod inner rod 18 is provided with a hexagonal boss 17, which is used to prevent the telescopic rod assembly from rotating along its axis by holding the hexagonal boss 17 when rotating the adjusting nut 21 slot.

[0050] like Figure 1 、 Figure 6 and Figure 7 As shown, the lower end of the outer rod 19 of the telescopic rod is provided with a bearing groove, which is connected to the threaded rod 25 through a bearing 26. A limiting groove is provided on the outer rod, which cooperates with the limiting screw 23 to prevent the telescopic inner rod 18 and the outer rod 19 from rotating relative to each other. A threaded connection with a self-locking function is adopted between the inner rod 18 of the telescopic rod and the threaded rod 25 to prevent unexpected displacement under axial load. The lead angle of the self-locking thread pair is smaller than the friction angle, and an axial-circumferential composite constraint is formed in combination with the limiting groove and the anti-rotation cylindrical surface. The telescopic rod assembly realizes seamless switching of "flexible adjustment-rigid fixation" during surgery through the dual locking mechanism of axial self-locking and circumferential limiting, and the adjustment process is convenient and efficient.

[0051] like Figure 1 and Figure 8As shown, the rotation adjustment assembly includes a rotation clamp 28, a first locking nut 32, a first elastic collet 31, a second locking nut 30, and a second elastic collet 29; the end of the telescopic rod outer rod 19 is processed with a rotation axis 20, and the rotation clamp is provided with a first through hole 281 and a second through hole 282 perpendicular to each other, and the ends of the first through hole and the second through hole both protrude from the rotation clamp to form a tube body, and as shown Figure 8 As shown, an external thread is provided, and the rotating axis of the outer rod of the telescopic rod can pass through the first through hole and be connected with the first elastic clamp on the other side. The rotating clamp 28 is fixed to the rotating axis 20 by the cooperation of the first elastic clamp 31 and the first locking nut 32. When the first locking nut 32 is not tightened, the rotating clamp 28 can rotate around the rotating axis 20 to form a rotating pair; the rotating clamp 28 is fixed to the holding screw 5 on the affected side by the cooperation of the second elastic clamp 29 and the second locking nut 30.

[0052] like Figures 1 to 8 As shown, the ipsilateral screw holding chain is close to the upper surface of the human body. The lever arm is short, minimizing the impact of deformation of the ipsilateral screw holding chain and the screw on the accuracy of pelvic fracture reduction. After the ipsilateral screw holding chain is secured, the three ipsilateral screw holding chains are mutually constrained. By tightening the first and second locking nuts, the ipsilateral screw holding chain and the pelvis form a rigid structure, resulting in a simple structure, convenient operation, and stable pelvic fixation.

[0053] The specific implementation steps of the device of this embodiment are: first, the three affected-side screw holding branches consisting of the universal ball joint assembly 2, the telescopic rod assembly 3, and the rotation adjustment assembly 4 are fixed to the adapter plate 10 of the reset force detection unit by screws to complete the installation of the affected-side screw holding branch; then, before reduction, the end position of the pelvic fracture reduction robot 6 is freely moved and rotated by manual adjustment, and the end position of the pelvic fracture reduction robot 6 is adjusted according to the actual position of the holding screw to ensure that the end of each branch is close to the surface of the affected pelvis and can quickly complete the cooperation with the holding screw 5; then, the hexagonal boss 17 is held to prevent the telescopic rod assembly from rotating along its axis, and at the same time, the adjusting nut slot 22 is rotated to adjust the telescopic rod outer rod 19 relative to the telescopic rod The position of the inner rod 18 completes the position adjustment of the telescopic rod assembly so that its bottom end is close to the position of the fractured side; at the same time, the rotating clamp 28 in the rotation adjustment assembly 4 is assembled with the holding screw 5, and the first locking nut 32 and the second locking nut 30 are tightened respectively to complete the self-locking of the rotation adjustment assembly; then the rotation adjustment screw 12 moves inward to press the locking ball bowl 14, and the ball joint is locked and fixed by the friction between the locking ball bowl 14 and the ball head 16, so that the single screw holding branch chain on the affected side forms a rigid connection structure with the affected pelvis 7; finally, repeat the locking steps of the single screw holding branch chain on the affected side according to the position of the fracture of the affected pelvis, adjust while fixing and complete the locking of the remaining two branches to complete the fixed hold of the affected pelvis 7.

[0054] Through the description of the above embodiments, it can be further expressed that the present invention also has the following technical effects: real-time reset force monitoring and safety assurance, the reset force detection unit is equipped with a six-dimensional force sensor, which can monitor the dynamic reset force during the reset process, and provide real-time feedback of the reset force data to avoid secondary damage caused by uneven or excessive force during the operation, thereby providing protection for the safety of the operation. Adaptive adjustment capability, the ipsilateral screw holding branch chain realizes multi-degree-of-freedom flexible adjustment of the branch chain end posture through the coordinated action of the universal ball joint assembly, the telescopic rod assembly and the rotation adjustment assembly to adapt to the different postures of the holding screw. High holding force and stable rigidity, after the three branches are locked, they form a rigid connection structure with the ipsilateral pelvis, combined with the self-locking thread design and high rigidity characteristics of the telescopic rod assembly, to provide strong holding force. Compact structure, easy operation, the device adopts a modular design, small size and detachable connection, to avoid the interference of excessive structural size on the intraoperative field of view and path planning.

[0055] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A pelvic gripping device for the affected side of a pelvic fracture reduction robot, characterized by: The affected-side pelvic holding device includes a reset force detection unit and an affected-side screw holding branch chain; The reset force detection unit includes a six-dimensional force sensor, a connecting shaft, and a connecting disk. The top end of the six-dimensional force sensor is connected to the pelvic fracture reduction robot actuator, and the bottom end is fixedly connected to the connecting shaft. The reset force detection unit is used to monitor and feedback the reset force vector parameters in real time. Three through holes are opened on the connecting disk to form a branch interface. The connecting line of the axis centers of the three branch interfaces forms an equilateral triangle. The said affected side screw holding chain is provided with three groups, each group including a universal ball joint assembly, a telescopic rod assembly and a rotation adjustment assembly; The universal ball joint assembly is provided with an end cover, and the outer circumference of the end cover is capable of being fixedly connected to the inner circumference of the branch joint; The telescopic rod assembly includes an inner telescopic rod and an outer telescopic rod, the inner telescopic rod is connected to the universal ball joint assembly, the outer telescopic rod is disposed outside the inner telescopic rod and can be extended or shortened along the axis of the inner telescopic rod, and the ratio of the length of the telescopic rod assembly when extended to the longest to the length of the axis connecting the adjacent branch joints is (100-120): (65-90); One end of the rotation adjustment component is connected to the telescopic rod component, and the other end is connected to the holding screw in a rotatable manner, and the holding screw is connected to the affected side pelvis.

2. The ipsilateral pelvic gripping device of the pelvic fracture reduction robot according to claim 1, characterized in that: The reset force detection unit also includes a locking nut; the top end of the connecting shaft is a disc structure, and the bottom end is a screw with an external thread. The disc structure is fixedly connected to the bottom end of the six-dimensional force sensor through the top end, and a through hole is provided at the center of the connecting disk. The screw at the bottom end of the connecting shaft passes through the through hole and is tightened and unscrewed by a threaded connection with the locking nut provided at the bottom end of the connecting disk.

3. The affected-side pelvic gripping device of the pelvic fracture reduction robot according to claim 1 or 2, characterized in that: The universal ball joint assembly is fixedly connected to the connecting plate. The universal ball joint assembly is used to install the telescopic rod assembly and provide three degrees of rotational freedom. After the rotation adjustment assembly is fixed to the holding screw, the universal ball joint assembly can be locked and fixed; the telescopic rod assembly and the universal ball joint assembly are fixedly connected by a pin. The telescopic rod assembly is used to provide telescopic displacement for the holding branch chain of the affected side screw; the rotation adjustment assembly is fixed to the end of the telescopic rod assembly and is used to adjust the angle between the holding branch chain of the affected side screw and the holding screw.

4. The affected-side pelvic gripping device of the pelvic fracture reduction robot according to claim 1 or 3, characterized in that: In addition to the end cover, the universal ball joint assembly also includes a ball joint seat, a locking ball bowl, an adjusting screw and a ball head. The ball joint seat is hollow, and the top is fixedly connected to the end cover. A locking ball bowl and a ball head are provided inside the ball joint seat. The outer periphery of the locking ball bowl matches the inner wall of the ball joint seat. The lower part of the locking ball bowl is an inverted bowl-shaped structure, and the inverted bowl-shaped structure is semi-enclosed on the upper part of the ball head. The ball head includes an upper spherical end and a lower straight rod end. The straight rod end passes through the bottom end of the ball joint seat. A spacer is provided between the spherical end of the ball head and the bowl-shaped structure. The spherical end of the ball head can form a three-degree-of-freedom ball pair under the covering of the bowl-shaped structure and the ball joint seat; a threaded through hole is opened at the top of the end cover, and the adjusting screw is threadedly connected with the internal thread of the threaded through hole through the external thread, and the bottom end of the adjusting screw can be abutted against the top of the locking ball bowl, and the locking ball bowl can be displaced downward by tightening the adjusting screw and the gap between the locking ball bowl and the spherical end of the ball head can be eliminated, and then the adjusting screw is further tightened to press the locking ball bowl and the ball head, and the motion locking is achieved by the friction between the locking ball bowl and the ball head.

5. The affected-side pelvic gripping device of the pelvic fracture reduction robot according to claim 1 or 4, characterized in that: The telescopic rod assembly also includes a threaded rod; the inner rod of the telescopic rod is a hollow structure, and an internal thread is provided on the circumference of the hollow inner wall. The threaded rod includes a threaded end and a clamping end. The threaded end is threadedly connected with the internal thread of the inner rod of the telescopic rod through an external thread to form a self-locking thread pair. The lead angle of the self-locking thread pair is smaller than the friction angle, so that the threaded connection between the inner rod of the telescopic rod and the threaded rod has a self-locking function.

6. The ipsilateral pelvic gripping device of the pelvic fracture reduction robot according to claim 5, characterized in that: The telescopic rod assembly also includes a limit screw, a threaded rod, a bearing, a retaining spring and an adjusting nut; the top end of the inner rod of the telescopic rod is fixedly connected to the straight rod end of the ball head, and the inner rod of the telescopic rod is connected to the universal ball joint assembly to form a ball pair; a shoulder is provided on the clamping end of the threaded rod, and the bearing is sleeved on the clamping end below the shoulder, and the retaining spring is provided on the clamping end below the bearing, and the retaining spring fixes the inner ring of the bearing to the clamping end of the threaded rod; the lowest end of the clamping end of the threaded rod is fixedly connected to the upper end of the adjusting nut, and an adjusting nut slot is provided in the center of the bottom end of the adjusting nut; the outer ends of the inner rod and the threaded rod are fixedly connected. The sleeve is provided with a telescopic rod outer rod, and the telescopic rod outer rod includes an outer rod body, a limiting groove and a rotating shaft; the outer rod body is a hollow structure, and the inner wall of the outer rod body is fixedly connected to the outer ring of the bearing, the groove center line of the limiting groove is parallel to the axial center line of the telescopic rod outer rod, and the limiting screw includes a screw part and a screw cover part, the width of the limiting groove is greater than the diameter of the screw part and smaller than the diameter of the screw cover part, the screw part passes through the limiting groove and is fixedly connected to the telescopic rod inner rod at the bottom, and the linear displacement of the telescopic rod inner rod relative to the telescopic rod outer rod along the axis of the telescopic rod assembly is realized by rotating the adjusting nut slot to form a moving pair.

7. The ipsilateral pelvic gripping device of the pelvic fracture reduction robot according to claim 6, characterized in that: The telescopic rod assembly also includes a hexagonal boss, which is arranged at the top of the inner rod of the telescopic rod. The hexagonal boss is used to prevent the telescopic rod assembly from rotating along its own axis by holding the hexagonal boss when rotating the adjustment nut slot; the inner rod of the telescopic rod is fixedly connected to the ball head by a pin.

8. The affected-side pelvic gripping device of the pelvic fracture reduction robot according to claim 6 or 7, characterized in that: The lower end of the inner wall of the outer rod body is provided with a bearing groove, and the outer rod of the telescopic rod is fixedly connected to the outer ring of the bearing through the bearing groove.

9. The ipsilateral pelvic gripping device of the pelvic fracture reduction robot according to claim 6, characterized in that: The rotation adjustment assembly includes a rotation clamp, a first locking nut, a first elastic collet, a second locking nut and a second elastic collet; the rotation clamp is provided with a first through hole and a second through hole perpendicular to each other, the ends of the first through hole and the second through hole both protrude from the rotation clamp to form a tube body, and an external thread is provided on the outside of the tube body, the rotating shaft of the outer rod of the telescopic rod can pass through the first through hole and be socketed with the first elastic collet on the other side, and the first locking nut can lock the first elastic collet and the end of the rotating shaft by tightening the outside of the first elastic collet; the second through hole is used to insert one end of the holding screw on the affected side and sequentially sleeve the second elastic collet and the second locking nut on the outside of the holding screw on the affected side, and the second elastic collet is locked to the end of the holding screw on the affected side by tightening the second locking nut on the outside of the second elastic collet.

10. The affected-side pelvic gripping device of the pelvic fracture reduction robot according to claim 6 or 7, characterized in that: The screw holding branch chain on the affected side is arranged above the operating table and close to the upper surface of the human body.

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