Mechanical arm for minimally invasive orthopedic surgery

Abstract

The present application relates to the technical field of orthopedic minimally invasive surgery equipment, and discloses a mechanical arm for orthopedic minimally invasive surgery, which comprises a base module, a coarse positioning module connected with the base module, a fine attitude module connected with the coarse positioning module and an end execution module connected with the fine attitude module; the base module comprises a base, universal casters are arranged at the bottom of the base, and two mounting flanges for providing rigid support are fixedly arranged at the top of the base; the coarse positioning module comprises a vertical lifting assembly and a horizontal telescopic assembly, the vertical lifting assembly comprises lifting columns arranged on the two mounting flanges respectively and a planetary roller screw, straight line guides are arranged in parallel on the side surface of the lifting columns, and sliders are arranged on the straight line guides. Through the modular architecture, high-rigidity transmission, multi-degree-of-freedom accurate driving and fiber force sensing, the present application realizes high flexibility of the orthopedic minimally invasive surgery mechanical arm, sub-millimeter level stable positioning, multi-surgical mode universal adaptation and intraoperative force feedback safety protection.

Description

Technical Field

[0001] This invention relates to the field of orthopedic minimally invasive surgical equipment technology, specifically to a robotic arm for orthopedic minimally invasive surgery. Background Technology

[0002] Minimally invasive orthopedic surgery has the advantages of less trauma, less bleeding, and faster postoperative recovery. It is the mainstream method for treating orthopedic diseases such as spinal, joint, and trauma. Minimally invasive orthopedic surgery uses robotic arms as the core clinical surgical equipment, which can assist doctors in achieving precise positioning, stable control, and standardized operation of surgical instruments.

[0003] While current robotic arms used in minimally invasive orthopedic surgery can meet the needs of basic surgeries, they still have many technical shortcomings in practical use:

[0004] (1) The existing robotic arm joints have unreasonable design of freedom and limited range of motion. When facing surgical areas with narrow and complex anatomical structures such as the spinal canal and joint cavity, the robotic arm rods and joints are prone to motion interference with human tissues or their own parts, forming blind spots in the operation, greatly reducing the accessibility of complex areas, and even increasing the risk of surgical operation.

[0005] (2) Existing robotic arms have weak anti-disturbance capabilities and insufficient positioning stability. During the operation, they are easily affected by external and internal factors such as the doctor's operation force, the patient's bone micro-movement during the operation, and the transmission gap of the equipment itself. It is difficult to maintain a high-precision positioning state at the sub-millimeter level, which can easily lead to positioning deviation of surgical instruments and deviation of operation trajectory.

[0006] (3) Most existing robotic arms are designed for a single surgical procedure or are only suitable for local operation steps of a certain type of surgery. They have limited functions and poor adaptability to different scenarios. For example, some robotic arms can only perform pedicle screw implantation in the spine, and some are only suitable for joint grinding surgery. They cannot be compatible with various minimally invasive orthopedic operations such as spine, joint, and trauma, thus limiting their clinical application. Summary of the Invention

[0007] The purpose of this invention is to address the aforementioned shortcomings of existing technologies by proposing a robotic arm for minimally invasive orthopedic surgery, thereby resolving issues such as insufficient movement flexibility, poor positioning stability, and limited functional adaptability in existing robotic arms for minimally invasive orthopedic surgery.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0009] A robotic arm for minimally invasive orthopedic surgery includes a base module, a coarse adjustment positioning module connected to the base module, a fine posture module connected to the coarse adjustment positioning module, and an end effector module connected to the fine posture module.

[0010] The base module includes a base, with omnidirectional casters at the bottom and two mounting flanges fixed at the top of the base to provide rigid support;

[0011] The coarse adjustment positioning module includes a vertical lifting component and a horizontal telescopic component. The vertical lifting component includes a lifting column and a planetary roller screw respectively mounted on two mounting flanges. A linear guide rail is arranged parallel to the side of the lifting column, and a slider is mounted on the linear guide rail. A servo motor is mounted at the bottom of the planetary roller screw. The planetary roller screw includes a lead screw and a nut sleeved on the lead screw. The nut is connected to the slider through a fixed base plate.

[0012] The horizontal telescopic assembly is a double rhomboid telescopic linkage mechanism, including a first-stage rhomboid assembly and a second-stage rhomboid assembly. Both the first-stage and second-stage rhomboid assemblies include four connecting rods that are hinged to form a rhomboid closed-loop structure. The first-stage and second-stage rhomboid assemblies are connected in series through a spatial pitch hinge hub. A frameless direct-drive torque motor for driving is embedded at the hinge point of each connecting rod.

[0013] The fine attitude module includes interconnected yaw rotation joints, pitch oscillation joints, and rotation joints; the yaw rotation joint includes a yaw shaft connected to the horizontal telescopic component, first cross roller bearings disposed at both ends of the yaw shaft, and a first brushless DC motor driving the yaw shaft; the pitch oscillation joint is installed at the end of the yaw shaft away from the horizontal telescopic component, and includes a cross universal joint and a second brushless DC motor; the rotation joint is coaxially nested in the middle of the yaw shaft and the pitch joint, and is driven by a third brushless DC motor.

[0014] Furthermore, the aforementioned robotic arm for minimally invasive orthopedic surgery includes a quick-release interface assembly, a surgical instrument mounting base, and a fiber optic tactile sensing assembly in its end-effector module. The quick-release interface assembly includes a housing fixedly connected to a universal joint, a positioning groove located at the end of the housing away from the universal joint, and a magnetic ring at the bottom of the positioning groove. The surgical instrument mounting base includes a positioning cone surface that matches the positioning groove, and a permanent magnet is mounted on the positioning cone surface. The fiber optic tactile sensing assembly includes a flexible polymer fiber optic array arranged around the outer wall of the surgical instrument mounting base. The fiber optic array is connected to a photoelectric signal processor for real-time detection of multidimensional force feedback and bone tissue breakthrough signals when the surgical instrument drills or grinds bone.

[0015] Furthermore, the aforementioned orthopedic minimally invasive surgical robotic arm includes a first connecting plate and a second connecting plate, which are respectively fixedly connected to the end of the first-stage rhomboid assembly and the beginning of the second-stage rhomboid assembly. A horizontal hinge shaft is provided between the first connecting plate and the second connecting plate. The two ends of the horizontal hinge shaft are rotatably connected to the first connecting plate and the second connecting plate respectively through second crossed roller bearings. A fourth brushless DC motor is coaxially provided at one end of the horizontal hinge shaft for driving the second connecting plate to rotate vertically relative to the first connecting plate.

[0016] Furthermore, the aforementioned robotic arm for minimally invasive orthopedic surgery has a hollow shaft structure for its horizontal hinge axis. Inside the hollow shaft structure, there is a wiring channel, through which cables or optical fibers connecting to the precision posture module are threaded.

[0017] Furthermore, in the aforementioned orthopedic minimally invasive surgical robotic arm, at least three pneumatic top pins are provided in the positioning groove of the quick-release interface component. The pneumatic top pins include a telescopic end, which abuts against the positioning cone surface of the surgical instrument mounting base.

[0018] Furthermore, the aforementioned orthopedic minimally invasive surgical robotic arm has a surgical instrument mounting base that is detachably equipped with any one of a bone drill module, a grinding drill module, or a pedicle screw implantation guide module.

[0019] Furthermore, in the aforementioned orthopedic minimally invasive surgery robotic arm, the side wall of the surgical instrument mounting base is provided with a micro-strain elastomer, and a flexible polymer fiber array is attached to the surface of the micro-strain elastomer by medical polyurethane adhesive. The micro-strain elastomer is a silicone rubber layer with a honeycomb-shaped hollow structure inside. The photoelectric signal processor is built into the base and is connected to the fiber array through internal wiring that passes through the vertical lifting component, the horizontal telescopic component, and the fine attitude module in sequence.

[0020] Furthermore, the robotic arm used in the aforementioned minimally invasive orthopedic surgery has corrugated dust covers covering the lifting column, linear guide, and planetary roller screw, and the frameless direct-drive torque motor is encapsulated with a medical-grade silicone sealing film.

[0021] Furthermore, the connecting rods of the aforementioned orthopedic minimally invasive surgical robotic arm are all made of carbon fiber composite round tubes, and the two ends of the connecting rods are injection molded with engineering plastic hinge joints with built-in stainless steel metal inserts.

[0022] Furthermore, in the aforementioned robotic arm for minimally invasive orthopedic surgery, anti-slip micro-tooth patterns are provided on the end face where the magnetic ring and the permanent magnet attract each other, and the magnetic pole distribution of the magnetic ring is set opposite to that of the permanent magnet to form a closed magnetic attraction circuit.

[0023] By adopting the above technical solution, the present invention has the following beneficial effects:

[0024] 1. The orthopedic minimally invasive surgical robotic arm of the present invention integrates a base module, a coarse adjustment positioning module, a fine posture module, and an end effector module into one unit. Through the combined action of these modules, the robotic arm achieves highly flexible movement in confined and complex surgical spaces, sub-millimeter-level high-precision positioning, universal adaptability to multiple surgical procedures, and real-time multi-dimensional force sensing during surgery. This significantly improves the operational efficiency, treatment accuracy, and clinical safety of orthopedic minimally invasive surgery, reduces hospital equipment procurement and maintenance costs, and is adaptable to various orthopedic minimally invasive clinical scenarios such as spinal, joint, and trauma surgeries.

[0025] 2. This invention, by configuring omnidirectional casters and double mounting flanges on the base module, ensures both flexible movement and stable fixation of the equipment during surgery, while also providing a rigid support foundation for the entire machine, effectively improving the overall structural rigidity and anti-tipping ability of the robotic arm. By integrating a vertical lifting component and a double-diamond telescopic linkage type horizontal telescopic component into the coarse adjustment positioning module, the vertical lifting component adopts a transmission structure using planetary roller screws and linear guides, achieving high transmission accuracy and strong load capacity, and realizing stable vertical stroke adjustment. The double-diamond telescopic linkage mechanism directly drives the hinge point through a frameless direct-drive torque motor, and in conjunction with the spatial pitch hinge hub, achieves large-stroke horizontal extension and pitch attitude adjustment, significantly expanding the robotic arm's working space, effectively avoiding motion interference problems in confined surgical areas, and eliminating surgical blind spots.

[0026] 3. The precision posture module integrates yaw rotation joints, pitch swing joints, and rotation joints. Each joint is driven by a cross roller bearing and a brushless DC motor, resulting in small transmission backlash and high positioning accuracy. This enables multi-dimensional precision posture adjustment of the end effector, accurately matching the operating angle and movement trajectory of surgical instruments. This ensures the flexibility and accuracy of intraoperative posture adjustment, meeting the sub-millimeter positioning requirements of minimally invasive orthopedic surgery. The end effector module is equipped with a quick-release interface component, a replaceable surgical instrument mounting base, and a fiber optic tactile sensing component. The quick-release interface component uses a magnetic ring and permanent magnet for magnetic attraction and pneumatic locking, ensuring precise positioning and convenient assembly / disassembly. It allows for quick replacement of bone drill modules, grinding drill modules, or pedicle screw implantation guide modules, achieving multi-operative compatibility and effectively reducing equipment procurement and maintenance costs. The fiber optic tactile sensing component uses a flexible polymer fiber array bonded to a micro-strain elastomer to detect multi-dimensional force feedback and bone tissue breakthrough signals during drilling and grinding of bone in real time. It has high intraoperative force sensing sensitivity and fast response speed, effectively avoiding excessive feeding of surgical instruments and damage to normal bone tissue, significantly improving the safety of surgical procedures.

[0027] 4. The lifting assembly is covered with a corrugated dust cover and the drive motor is encapsulated with a medical-grade silicone sealing film. The connecting rod is made of carbon fiber composite round tube with an engineering plastic hinge joint with built-in stainless steel inserts. The hollow hinge shaft design has a cable routing channel, which not only ensures the dustproof and sealing performance of the equipment and is suitable for sterile surgical environments, but also reduces the weight of the robotic arm, improves the structural strength, and simplifies the internal cable layout. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the internal structure of the device;

[0029] Figure 2 This is a schematic diagram of the external structure of the device;

[0030] Figure 3 This is a structural diagram of the fine attitude module;

[0031] Figure 4A schematic diagram of the quick-release interface assembly and surgical instrument mounting base;

[0032] Figure 5 A schematic diagram of a guide module for pedicle screw implantation;

[0033] Figure 6 This is a structural diagram of the grinding and drilling module;

[0034] Figure 7 This is a structural diagram of the bone drill module;

[0035] The components include: 1. Base, 2. Universal casters, 3. Mounting flange, 4. Lifting column, 5. Linear guide rail, 6. Slider, 7. Servo motor, 8. Lead screw, 9. Nut, 10. Fixed base plate, 11. Connecting rod, 12. Yaw shaft, 13. First crossed roller bearing, 14. Universal joint, 15. Housing, 16. Positioning groove, 17. Magnetic ring, 18. Positioning cone surface, 19. Permanent magnet, 20. Fiber optic array, 21. First connecting plate, 22. Second connecting plate, 23. Horizontal hinge shaft, 24. Second crossed roller bearing, 25. Pneumatic top pin, 26. Bone drill module, 27. Grinding drill module, 28. Pedicle screw implantation guide module, 29. Corrugated dust cover, 30. Hinge joint. Detailed Implementation

[0036] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0037] like Figures 1 to 7 As shown in the figure, this embodiment provides a robotic arm for minimally invasive orthopedic surgery, including a base module, a coarse adjustment and positioning module connected to the base module, a fine posture module connected to the coarse adjustment and positioning module, and an end effector module connected to the fine posture module. The base module is used for overall support and movement fixation, the coarse adjustment and positioning module is used to achieve coarse adjustment of the robotic arm's spatial position over a wide range, the fine posture module is used to achieve sub-millimeter-level fine adjustment of the end effector's posture, and the end effector module is used to mount surgical instruments and sense multi-dimensional force signals during surgery in real time. The four modules work together to meet the precise operation requirements of minimally invasive orthopedic surgery.

[0038] The base module includes a base 1, with omnidirectional casters 2 at the bottom of the base 1. The omnidirectional casters 2 are silent medical casters that can rotate freely 360°, facilitating flexible movement of the entire machine in the operating room. The casters are equipped with a locking structure for stable fixation during surgery. Two mounting flanges 3 are fixedly installed on the top of the base 1 to provide rigid support. The two mounting flanges 3 are symmetrically arranged and made of high-strength aluminum alloy. They are rigidly connected to the base 1 by bolts, providing a stable installation foundation for the coarse adjustment positioning module and improving the overall structural rigidity and anti-overturning ability of the machine.

[0039] The coarse adjustment positioning module includes a vertical lifting assembly and a horizontal telescopic assembly. The vertical lifting assembly includes a lifting column 4 and a planetary roller screw, each mounted on one of the two mounting flanges 3. The lifting column 4 is a hollow square steel structure, vertically fixed to the mounting flange 3. A linear guide rail 5 is parallel to the side of the lifting column 4 and is bolted to the side wall of the lifting column 4. A slider 6 is mounted on the linear guide rail 5, and the slider 6 slides with the linear guide rail 5 to ensure the smoothness of the lifting movement. A servo motor 7 is mounted at the bottom of the planetary roller screw. The servo motor 7 is fixed to the mounting flange 3 via a motor mount. The planetary roller screw includes a lead screw 8 and a nut 9 sleeved on the lead screw 8. The lead screw 8 is arranged vertically, and its lower end is rigidly connected to the output shaft of the servo motor 7. The nut 9 is connected to the slider 6 via a fixed base plate 10. The servo motor 7 drives the lead screw 8 to rotate, which in turn drives the nut 9 to move along the axial direction of the lead screw 8. This, in turn, drives the slider 6 to slide along the linear guide rail 5 via the fixed base plate 10, thereby achieving precise vertical lifting and lowering adjustment. The stroke range is 0-800mm, and the positioning accuracy reaches ±0.1mm.

[0040] The horizontal telescopic assembly is a double-rhomboid telescopic linkage mechanism, including a first-stage rhomboid assembly and a second-stage rhomboid assembly. Both the first-stage and second-stage rhomboid assemblies consist of four connecting rods 11 hinged together to form a rhomboid closed-loop structure. The four connecting rods 11 of a single-stage rhomboid assembly are of the same length, and the hinge points form the four vertices of the rhombus, enabling telescopic and folding movements. The first-stage and second-stage rhomboid assemblies are connected in series via a spatial pitch hinge hub, allowing the two stages of the rhomboid assemblies to rotate relative to each other, expanding the attitude adjustment range of the horizontal telescopic movement. Each connecting rod 11 is equipped with a frameless direct-drive torque motor for driving. The frameless direct-drive torque motor is coaxially integrated at the hinge point, directly driving the relative rotation of the connecting rods 11 without intermediate transmission links, resulting in high transmission efficiency and fast response speed. The telescopic stroke of a single-stage rhomboid assembly is 0-600mm, and the total telescopic stroke after the two stages are connected in series can reach 0-1200mm, effectively expanding the horizontal working space of the robotic arm.

[0041] The fine attitude module includes interconnected yaw rotation joints, pitch oscillation joints, and rotation joints. The yaw rotation joint includes a yaw shaft 12 connected to the horizontal telescopic assembly, first crossed roller bearings 13 at both ends of the yaw shaft 12, and a first brushless DC motor driving the yaw shaft 12. The yaw shaft 12 is horizontally arranged, with one end rigidly connected to the end of the second-stage diamond-shaped assembly, and both ends rotated via the first crossed roller bearings 13. The first brushless DC motor is fixed to one side of the yaw shaft 12, and its output shaft is coaxially connected to the yaw shaft 12, driving the yaw shaft 12 to rotate around a horizontal axis with a rotation angle range of ±180° and a positioning accuracy of ±0.05°. The pitch oscillation joint is installed at the end of the yaw shaft 12 furthest from the horizontal telescopic assembly. The system includes a cross-shaped universal joint 14 and a second brushless DC motor. One end of the cross-shaped universal joint 14 is fixedly connected to the yaw axis 12, and the other end is connected to the end effector module. The second brushless DC motor drives the cross-shaped universal joint 14 to swing, with a pitch angle range of ±90°, which can flexibly adjust the pitch attitude of the end effector module. The rotation joint is coaxially nested between the yaw axis 12 and the pitch joint, and is driven by a third brushless DC motor. The output shaft of the third brushless DC motor is coaxially connected to the end effector module, driving the end effector module to rotate around its own axis with a rotation angle range of 0-360°. The three joints work together to achieve six degrees of freedom attitude adjustment of the end effector module, accurately matching the complex operating angle requirements of orthopedic minimally invasive surgery.

[0042] The spatial pitch hinge hub includes a first connecting plate 21 and a second connecting plate 22, which are respectively fixedly connected to the end of the first-stage rhomboid assembly and the beginning of the second-stage rhomboid assembly. The first connecting plate 21 is rigidly welded to the hinge point of the connecting rod 11 at the end of the first-stage rhomboid assembly, and the second connecting plate 22 is rigidly welded to the hinge point of the connecting rod 11 at the beginning of the second-stage rhomboid assembly. A horizontal hinge shaft 23 is provided between the first connecting plate 21 and the second connecting plate 22. The horizontal hinge shaft 23 is arranged laterally, with both ends extending to the outside of the first connecting plate 21 and the second connecting plate 22. The two ends of the horizontal hinge shaft 23 are connected by second crossed roller shafts. Bearing 24 is rotatably connected to the first connecting plate 21 and the second connecting plate 22 respectively, ensuring the smoothness and accuracy of the hinge shaft rotation; one end of the horizontal hinge shaft 23 is coaxially provided with a fourth brushless DC motor for driving the second connecting plate 22 to tilt vertically relative to the first connecting plate 21. The fourth brushless DC motor is fixed to the outside of the first connecting plate 21, and its output shaft is rigidly connected to the horizontal hinge shaft 23, driving the second connecting plate 22 to tilt around the horizontal hinge shaft 23. The tilt angle range is ±60°, realizing the attitude adjustment between the two-stage rhomboid components and avoiding motion interference in the narrow surgical space.

[0043] The horizontal hinge shaft 23 is a hollow shaft structure. A wiring channel with a diameter of 15mm is formed inside the hollow shaft structure. Cables or optical fibers connecting to the fine posture module are run through the wiring channel. The cables and optical fibers are arranged neatly inside the hollow shaft to avoid external wear, simplify the overall wiring structure, and improve the cleanliness and safety of the equipment.

[0044] The end effector module includes a quick-release interface assembly, a surgical instrument mounting base, and a fiber optic tactile sensing assembly. The quick-release interface assembly includes a housing 15 fixedly connected to a universal joint 14. The housing 15 is a cylindrical aluminum alloy structure, rigidly connected at one end to the cross-shaped universal joint 14. A positioning groove 16 is located at the end of the housing 15 furthest from the universal joint 14. The positioning groove 16 is a tapered groove with a taper of 1:5. A magnetic ring 17, which is a ring-shaped permanent magnet 19, is located at the bottom of the positioning groove 16 and is coaxially arranged with it. The surgical instrument mounting base includes a positioning conical surface 18 that matches the positioning groove 16, with the same taper as the positioning groove 16. It can be precisely embedded in the positioning groove 16. A permanent magnet 19 is set on the positioning cone surface 18. The permanent magnet 19 has a ring structure and is embedded in the middle of the positioning cone surface 18, coaxially corresponding to the magnetic guide ring 17. At least three pneumatic top pins 25 are set in the positioning groove 16 of the quick-release interface assembly. The three pneumatic top pins 25 are evenly arranged around the circumference of the positioning groove 16. The pneumatic top pin 25 includes a telescopic end, which is made of hard alloy material. The telescopic end abuts against the positioning cone surface 18 of the surgical instrument mounting seat. The pneumatic top pin 25 is driven to extend and retract by air pressure. When it extends, it presses against the positioning cone surface 18 to achieve rigid fixation of the surgical instrument mounting seat. When it retracts, it can be quickly disassembled. The disassembly and assembly time is less than 10 seconds, which is suitable for the need for quick instrument replacement during operation.

[0045] The surgical instrument mounting base is detachably equipped with any one of the following: a bone drill module 26, a grinding drill module 27, or a pedicle screw implantation guide module 28. The bone drill module 26 is used for bone drilling operations, the grinding drill module 27 is used for bone grinding and trimming operations, and the pedicle screw implantation guide module 28 is used for precise implantation guidance of pedicle screws in the spine. The three modules are detachably connected to the surgical instrument mounting base by bolts and can be quickly replaced according to different minimally invasive orthopedic procedures, achieving compatibility with multiple procedures.

[0046] The fiber optic tactile sensing component includes a flexible polymer fiber array 20 arranged around the outer wall of the surgical instrument mounting base. The flexible polymer fiber array 20 consists of eight flexible polymer fibers, evenly arranged around the circumference of the surgical instrument mounting base. The fiber array 20 is connected to a photoelectric signal processor for real-time detection of multidimensional force feedback and bone tissue breakthrough signals when the surgical instrument is drilling or grinding bone. A micro-strain elastomer is installed on the side wall of the surgical instrument mounting base. The micro-strain elastomer is a silicone rubber layer with an internal honeycomb-like perforation structure, 2 mm thick, with a honeycomb perforation diameter of 1 mm, enabling precise detection of minute deformations. The flexible polymer fiber array 20 is bonded with medical polyurethane adhesive. The adhesive is bonded to the surface of the micro-strain elastomer. The medical polyurethane adhesive has good biocompatibility and high bonding strength, ensuring a tight fit between the fiber optic array 20 and the micro-strain elastomer. The photoelectric signal processor is built into the base 1 and is connected to the fiber optic array 20 through internal wiring that passes through the vertical lifting component, the horizontal telescopic component, and the fine attitude module. The internal wiring is arranged along the hollow structure of each module to avoid signal interference. The photoelectric signal processor can collect the changes in the optical signal of the fiber optic array 20 in real time and convert them into multi-dimensional force data. The force detection range is 0-50N, and the detection accuracy is ±0.1N. It can accurately identify the force changes during bone tissue drilling and grinding and capture bone tissue breakthrough signals in a timely manner.

[0047] The lifting column 4, linear guide rail 5, and planetary roller screw are all fitted with corrugated dust covers 29. The corrugated dust covers 29 are made of medical-grade flexible rubber and can extend and retract with the lifting movement to prevent dust and body fluids from entering the transmission components during the operation, thus avoiding wear and contamination of the components. The frameless direct drive torque motor is encapsulated with a medical-grade silicone sealing film. The medical-grade silicone sealing film is waterproof, dustproof, and sterile, which meets the sterile environment requirements of the operating room, protects the internal structure of the motor, and extends the service life of the motor.

[0048] All connecting rods 11 are made of carbon fiber composite round tubes with an outer diameter of 20mm and a wall thickness of 2mm. They are lightweight and high-strength, which can reduce the overall weight of the robotic arm and improve its flexibility. Both ends of the connecting rods 11 are injection molded with engineering plastic hinge joints 30 with built-in stainless steel metal inserts. The stainless steel metal inserts ensure the strength and wear resistance of the hinge points, while the engineering plastic hinge joints 30 have good insulation and biocompatibility, making them suitable for use in surgical environments.

[0049] The magnetic guide ring 17 and the permanent magnet 19 are both provided with anti-slip micro-tooth patterns on their end faces where they are attracted to each other. The anti-slip micro-tooth patterns are fine triangular tooth structures, which can increase the friction between the magnetic guide ring 17 and the permanent magnet 19 and prevent loosening caused by vibration during the operation. In addition, the magnetic pole distribution of the magnetic guide ring 17 is set opposite to that of the permanent magnet 19 to form a closed magnetic attraction circuit. The magnetic guide ring 17 and the permanent magnet 19 generate a strong magnetic attraction force through the opposite magnetic pole setting. The magnetic attraction strength reaches 100N. With the mechanical locking of the pneumatic top pin 25, the double fixation ensures the stability of the surgical instrument mounting base and avoids loosening and displacement during the operation.

[0050] The orthopedic minimally invasive surgical robotic arm of this embodiment ensures flexible movement and stable fixation through a base module. A coarse adjustment positioning module enables large-scale spatial coarse adjustment, while a double-diamond telescopic linkage mechanism, combined with a frameless direct-drive torque motor, expands the workspace and avoids motion interference. A fine posture module with three joints working in tandem achieves sub-millimeter-level fine adjustment of the end effector posture. A quick-release interface on the end effector module adapts to various surgical instruments, and a fiber optic tactile sensing component detects multidimensional forces and bone tissue breakthrough signals in real time during surgery. The entire machine exhibits high structural rigidity, high mobility, and good positioning stability, making it suitable for various minimally invasive orthopedic procedures, including spinal, joint, and trauma surgeries. This effectively solves the problems of blind spots, positioning deviations, and limited surgical procedure compatibility found in existing robotic arms.

Claims

1. A robotic arm for minimally invasive orthopedic surgery, characterized in that, It includes a base module, a coarse adjustment positioning module connected to the base module, a fine attitude module connected to the coarse adjustment positioning module, and an end effector module connected to the fine attitude module; The base module includes a base (1), a universal caster (2) is provided at the bottom of the base (1), and two mounting flanges (3) are fixedly provided at the top of the base (1) to provide rigid support. The coarse adjustment positioning module includes a vertical lifting component and a horizontal telescopic component. The vertical lifting component includes a lifting column (4) and a planetary roller screw respectively set on two mounting flanges (3). A linear guide rail (5) is arranged parallel to the side of the lifting column (4), and a slider (6) is set on the linear guide rail (5). A servo motor (7) is set at the bottom of the planetary roller screw. The planetary roller screw includes a lead screw (8) and a nut (9) sleeved on the lead screw (8). The nut (9) is connected to the slider (6) through a fixed base plate (10). The horizontal telescopic component is a double-rhomboid telescopic linkage mechanism, including a first-stage rhomboid component and a second-stage rhomboid component. Both the first-stage and second-stage rhomboid components include four connecting rods (11) hinged to form a rhomboid closed-loop structure. The first-stage and second-stage rhomboid components are connected in series through a spatial pitch hinge hub. The connecting rods (11) are all carbon fiber composite round tubes, and both ends of the connecting rods (11) are injection molded with engineering plastic hinge joints (30) with built-in stainless steel metal inserts. The hinge points of the hinge joints (30) are all equipped with frameless direct-drive torque motors for driving. The double-rhomboid telescopic linkage mechanism directly drives the hinge points through frameless direct-drive torque motors. The combined space pitch hinge hub realizes large horizontal stroke extension and pitch attitude adjustment; the fine attitude module includes a yaw rotation joint, a pitch swing joint and a spin joint connected to each other; the yaw rotation joint includes a yaw shaft (12) connected to the horizontal extension component, a first cross roller bearing (13) set at both ends of the yaw shaft (12) and a first brushless DC motor driving the yaw shaft (12); the pitch swing joint is installed at the end of the yaw shaft (12) away from the horizontal extension component, including a cross universal joint (14) and a second brushless DC motor; the spin joint is coaxially nested in the middle of the yaw shaft (12) and the pitch joint, and is driven by a third brushless DC motor; The end effector module includes a quick-release interface assembly, a surgical instrument mounting base, and a fiber optic tactile sensing assembly. The quick-release interface assembly includes a housing (15) fixedly connected to a universal joint (14), a positioning groove (16) located at the end of the housing (15) away from the universal joint (14), a magnetic ring (17) located at the bottom of the positioning groove (16), and a positioning cone (18) matching the positioning groove (16). A permanent magnet (19) is located on the positioning cone (18). The fiber optic tactile sensing assembly includes a flexible polymer fiber array (20) arranged around the outer wall of the surgical instrument mounting base. The fiber array (20) is connected to a photoelectric signal processor for real-time detection of multidimensional force feedback and bone tissue breakthrough signals when the surgical instrument drills or grinds bone. The spatial pitch hinge hub includes a first connecting plate (21) and a second connecting plate (22) that are fixedly connected to the end of the first-stage rhomboid component and the beginning of the second-stage rhomboid component, respectively. A horizontal hinge shaft (23) is provided between the first connecting plate (21) and the second connecting plate (22). The two ends of the horizontal hinge shaft (23) are rotatably connected to the first connecting plate (21) and the second connecting plate (22) respectively through a second crossed roller bearing (24). A fourth brushless DC motor is coaxially provided at the end of the horizontal hinge shaft (23) for driving the second connecting plate (22) to pitch and rotate vertically relative to the first connecting plate (21). The fourth brushless DC motor is fixed to the outside of the first connecting plate (21), and its output shaft is rigidly connected to the horizontal hinge shaft (23) to drive the second connecting plate (22) to pitch and rotate around the horizontal hinge shaft (23).

2. The robotic arm for minimally invasive orthopedic surgery according to claim 1, characterized in that, The horizontal hinge shaft (23) is a hollow shaft structure, and a wiring channel is formed inside the hollow shaft structure. Cables or optical fibers for connecting the fine attitude module are threaded through the wiring channel.

3. The robotic arm for minimally invasive orthopedic surgery according to claim 1, characterized in that, At least three pneumatic top pins (25) are provided in the positioning groove (16) of the quick-release interface assembly. The pneumatic top pins (25) include telescopic ends, which abut against the positioning cone surface (18) of the surgical instrument mounting base.

4. The robotic arm for minimally invasive orthopedic surgery according to claim 3, characterized in that, The surgical instrument mounting base is detachably provided with any one of the following: a bone drill module (26), a grinding drill module (27), or a pedicle screw implantation guide module (28).

5. The robotic arm for minimally invasive orthopedic surgery according to claim 1, characterized in that, The side wall of the surgical instrument mounting base is provided with a micro-strain elastomer. The flexible polymer fiber array (20) is attached to the surface of the micro-strain elastomer by medical polyurethane adhesive. The micro-strain elastomer is a silicone rubber layer with a honeycomb hollow structure inside. The photoelectric signal processor is built into the base (1) and is connected to the fiber array (20) by passing through the vertical lifting component, the horizontal telescopic component and the fine attitude module in sequence through the internal wiring.

6. The robotic arm for minimally invasive orthopedic surgery according to claim 1, characterized in that, The lifting column (4), linear guide rail (5) and planetary roller screw are covered with corrugated dust covers (29), and the frameless direct drive torque motor is encapsulated with a medical-grade silicone sealing film.

7. The robotic arm for minimally invasive orthopedic surgery according to claim 1, characterized in that, The magnetic ring (17) and the permanent magnet (19) are provided with anti-slip micro-tooth patterns on their end faces where they attract each other. The magnetic pole distribution of the magnetic ring (17) is opposite to that of the permanent magnet (19) to form a closed magnetic attraction circuit.

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