Parallel mechanism for surgery, method of use, and bone surgery robot using the same

Abstract

The present invention belongs to the technical field of orthopedic surgical robots, and specifically relates to a parallel mechanism for surgery, a method of use, and a bone surgical robot using the same. A parallel mechanism for surgery of the present invention includes a static platform fixedly mounted on a surgical device, a dynamic platform connected to a surgical module for driving the surgical module to change its posture, and three sets of closed-loop branches rotatably arranged between the static platform and the dynamic platform; when the three sets of closed-loop branches are in their original state, the plane where the dynamic platform is located is perpendicular to the plane where the static platform is located. When the parallel mechanism of the present invention adopts the original state, the static platform and the dynamic platform, whose planes are perpendicular to each other, form a parallel mechanism of 3‑R(Pa)RS configuration through the three sets of closed-loop branches, thereby realizing the relative movement of the six degrees of freedom of the dynamic platform, ensuring the accuracy of the movement of the surgical module installed on the dynamic platform, and avoiding the problem of insufficient load-bearing capacity caused by the use of serial robotic arms in the prior art.

Description

Technical Field

[0001] The present invention belongs to the technical field of bone surgical robots, and in particular relates to a surgical parallel mechanism, a method of use, and a bone surgical robot using the same. Background Art

[0002] Orthopedic surgical robots adopt precise surgical concepts and technical means, combined with the latest biomedical engineering research results, to achieve precise surgical operations with minimal damage through accurate, safe and stable operations.

[0003] The robotic arms of existing orthopedic surgical robots mostly use serial robotic arms with a relatively low load-bearing capacity. For example, the orthopedic surgical robot described in patent CN114869474A achieves stable support through casters and support leg structures installed on the bottom plate of the trolley. However, it uses industrial collaborative serial robotic arms, and the load-bearing ratio of serial robotic arms is usually low. When a certain load is exceeded during the execution of the task, the end movement accuracy cannot be guaranteed. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defect of low load-bearing ratio of serial robotic arms used in orthopedic surgical robots in the prior art, and to provide a parallel mechanism that can improve the load-bearing ratio of the orthopedic surgical robot and a orthopedic surgical robot using the parallel mechanism.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a parallel mechanism for surgery, comprising a static platform fixedly mounted on the surgical equipment, a dynamic platform connected to the surgical module for driving the surgical module to change its posture, and three sets of closed-loop branches rotatably arranged between the static platform and the dynamic platform; when the three sets of closed-loop branches are in their original state, the plane where the dynamic platform is located is perpendicular to the plane where the static platform is located; wherein,

[0006] The closed-loop branched chain comprises:

[0007] A parallelogram sub-chain is rotatably connected to the static platform via a T-shaped connecting rod;

[0008] a first drive unit, rotatably mounted on the static platform, wherein an output shaft of the first drive unit is coaxially arranged with a vertical rod of the T-shaped connecting rod;

[0009] A second driving unit is fixedly mounted on the parallelogram sub-chain and drives the parallelogram sub-chain to rotate along the output shaft axis of the first driving unit through a transmission mechanism;

[0010] A driven connecting rod, one end of which is rotatably arranged on a parallelogram sub-chain away from the static platform, and the other end of which is rotatably connected to the dynamic platform;

[0011] The first driving unit and the second driving unit drive the movable platform to perform translation in the X-axis direction, the Y-axis direction, and the Z-axis direction and rotation along the X-axis, the Y-axis, and the Z-axis through the parallelogram sub-chain and the driven connecting rod.

[0012] Furthermore, the static platform and the dynamic platform are both equilateral triangle structures, and the three groups of closed-loop branch chains are all rotatably connected to the corresponding vertex angles of the static platform and the dynamic platform.

[0013] Furthermore, the parallelogram sub-chain includes a first link, a second link, a third link, and a fourth link that are sequentially connected end to end to form a parallelogram structure; wherein,

[0014] The second driving unit is installed on the first connecting rod; the two ends of the cross rod of the T-shaped connecting rod are respectively rotatably connected to the second connecting rod and the fourth connecting rod; the driven connecting rod is rotatably connected to the second connecting rod and the fourth connecting rod away from one end of the static platform.

[0015] Furthermore, the transmission mechanism includes:

[0016] a driving gear, coaxially arranged with the output shaft of the second driving unit;

[0017] The driven sector gear is meshed and connected with the driving gear and is installed on the vertical rod of the T-shaped connecting rod; the driven sector gear drives the parallelogram branch chain to rotate along the vertical rod of the T-shaped connecting rod.

[0018] Furthermore, the transmission ratio n of the driving gear and the driven sector gear, and the sector angle a of the driven sector gear, where n=5-10, a=90°-120°, can drive the dynamic platform to achieve translation and rotation at different speeds within a workspace that meets the requirements of the corresponding procedure.

[0019] Furthermore, the three driven connecting rods are all rotationally connected to the moving platform through a ball motion pair S.

[0020] Furthermore, lifting ears extend from the top corners on both sides and the bottom top corner of the static platform respectively, and the closed-loop branch chain is hinged to the static platform through the lifting ears, and the static platform and the closed-loop branch chain form a rotational motion pair R.

[0021] A method for using a parallel mechanism for surgery, including an X-axis translation method, a Y-axis translation method, a Z-axis translation method, an X-axis rotation method, a Y-axis rotation method, and a Z-axis rotation method of a moving platform, wherein:

[0022] X-axis translation method: simultaneously starting the first driving units on the left and right sides of the static platform to drive the parallelogram sub-chain to move, thereby driving the dynamic platform to translate along the X-axis direction through the driven connecting rod;

[0023] Y-axis translation method: activating the first driving unit on one side of the left and right positions of the static platform, and driving the dynamic platform to translate along the Y-axis direction by changing the posture of the closed-loop branch chain on one side of the static platform;

[0024] Z-axis translation method: simultaneously start the first drive unit at the bottom of the static platform and the second drive units on the left and right sides of the static platform, and drive the dynamic platform to translate along the Z-axis through the parallelogram sub-chain and the driven connecting rod;

[0025] X-axis rotation method: start the second driving unit on one of the left and right sides of the static platform, and drive the dynamic platform to rotate along the X-axis through the parallelogram sub-chain and the driven connecting rod;

[0026] Y-axis rotation method: start the first driving unit at the lower part of the static platform, and drive the dynamic platform to rotate along the Y-axis through the parallelogram sub-chain and the driven connecting rod;

[0027] Z-axis rotation method: start the second driving units on both sides of the static platform, and drive the dynamic platform to rotate along the Z-axis by changing the height h1 of the parallelogram sub-chain.

[0028] An orthopedic surgical robot comprises a trolley, an orthopedic surgical module for orthopedic surgery, and a surgical parallel mechanism as described above; wherein,

[0029] The static platform of the parallel mechanism is fixedly mounted on the orthopedic surgery trolley, and the orthopedic surgery module is fixedly mounted on the dynamic platform of the parallel mechanism.

[0030] Furthermore, it also includes a force sensing module installed on the dynamic platform for real-time data detection.

[0031] The beneficial effect of a surgical parallel mechanism of the present invention is that when the parallel mechanism of the present invention is in its original state, the static platform and the moving platform, whose planes are perpendicular to each other, form a parallel mechanism of 3-R(Pa)RS configuration through three sets of closed-loop branches, thereby realizing the relative movement of the six degrees of freedom of the moving platform, ensuring the accuracy of the movement of the surgical module installed on the moving platform, and avoiding the problem of insufficient load-bearing capacity caused by the use of serial robotic arms in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Figure 1 is a first-perspective stereogram of a parallel mechanism according to an embodiment of the present invention;

[0034] Figure 2is a first-perspective stereogram of a parallel mechanism according to an embodiment of the present invention;

[0035] Figure 3 1. It is a schematic structural diagram from a first perspective of a closed-loop branch chain in a parallel mechanism according to an embodiment of the present invention;

[0036] Figure 4 2. It is a schematic structural diagram from a second perspective of the closed-loop branch chain in the parallel mechanism according to an embodiment of the present invention;

[0037] Figure 5 1. This is a schematic structural diagram of a parallelogram sub-chain in a parallel mechanism according to an embodiment of the present invention from a first perspective;

[0038] Figure 6 2. It is a schematic structural diagram from a second perspective of the parallelogram sub-chain in the parallel mechanism according to an embodiment of the present invention.

[0039] In the figure: 1. static platform, 11. lifting eye, 2. dynamic platform, 3. closed-loop branch chain, 31. parallelogram sub-chain, 311. first connecting rod, 312. second connecting rod, 313. third connecting rod, 314. fourth connecting rod, 32. first driving unit, 33. T-type connecting rod, 34. second driving unit, 35. driven connecting rod, 36. transmission mechanism, 361. driving gear, 362. driven sector gear, 37. ball motion pair. DETAILED DESCRIPTION

[0040] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0041] like Figures 1-6 The specific embodiment of a surgical parallel mechanism of the present invention shown in the figure comprises a static platform 1 fixedly mounted on the surgical device, a dynamic platform 2 connected to the surgical module for driving the surgical module to change its posture, and three sets of closed-loop branch chains 3 rotatably arranged between the static platform 1 and the dynamic platform 2. When the three sets of closed-loop branch chains 3 are all in their original state, the plane where the dynamic platform 2 is located is perpendicular to the plane where the static platform 1 is located. The closed-loop branch chains 3 include a parallelogram sub-chain 31, a first drive unit 32, a second drive unit 34, and a driven connecting rod 35. The middle parallelogram sub-chain 31 is rotatably connected to the static platform 1 through a T-shaped connecting rod 33. The first drive unit 32 is rotatably installed with the static platform 1, and the output shaft of the first drive unit 32 is coaxially arranged with the vertical rod of the T-shaped connecting rod 33. The second drive unit 34 is fixedly installed on the parallelogram sub-chain 31, and the parallelogram sub-chain 31 is driven to rotate along the output shaft axis of the first drive unit 32 through the transmission mechanism 36. One end of the driven connecting rod 35 is rotatably set on the parallelogram sub-chain 31 away from the static platform 1, and the other end is rotatably connected to the dynamic platform 2.

[0042] like Figure 2 As shown, the first drive unit 32 and the second drive unit 34 drive the movable platform 2 through the parallelogram sub-chain 31 and the driven connecting rod 35 to perform translation in the X-axis, Y-axis, and Z-axis directions, as well as rotation along the X-axis, Y-axis, and Z-axis. In this embodiment, the static platform 1 and the movable platform 2 are both equilateral triangle structures, and the three sets of closed-loop branch chains 3 are all rotatably connected to the corresponding vertex angles of the static platform 1 and the movable platform 2.

[0043] The surgical parallel mechanism of the present invention includes a static platform 1, a closed-loop branch chain 3, and a dynamic platform 2. The static platform 1 is a fixed end, fixed to a surgical device, such as a trolley. Lifting ears 11 extend from the upper left and right sides and the lower middle position of the static platform 1, respectively, and are hinged to one side of the closed-loop branch chain 3 to form a rotational motion pair R. The dynamic platform 23 is an equilateral triangle with holes at its three apex corners, each of which is fixed with a ball motion pair 37S, and is hinged to the other side of the closed-loop branch chain 3. There are three closed-loop branch chains 3, and their structures are all the same. The static platform 1 and the dynamic platform 2 are connected by three closed-loop branch chains 3 to form a parallel mechanism of 3-R(Pa)RS configuration, which realizes the 6-degree-of-freedom center point movement of the dynamic platform 2 through relative motion. When the parallel mechanism of the present invention is in its original state, the static platform 1 and the moving platform 2, whose planes are perpendicular to each other, form a parallel mechanism of 3-R(Pa)RS configuration through three sets of closed-loop branches 3, thereby realizing the relative movement of the six degrees of freedom of the moving platform 2, ensuring the accuracy of the movement of the surgical module installed on the moving platform 2, and avoiding the problem of insufficient load-bearing capacity caused by the use of serial robotic arms in the prior art.

[0044] The parallelogram sub-chain 31 in this embodiment includes a first link 311, a second link 312, a third link 313 and a fourth link 314 which are connected end to end in sequence to form a parallelogram structure; wherein the second drive unit 34 is installed on the first link 311; the two ends of the cross bar of the T-shaped link 33 are respectively rotatably connected to the second link 312 and the fourth link 314; the driven connecting rod 35 is rotatably connected to the second link 312 and the fourth link 314 at one end away from the static platform 1.

[0045] The second driving unit 34 drives the first height h1 of the parallelogram sub-chain 31 to increase or decrease, thereby realizing the rotation or translation of the moving platform 2. Figure 4 As shown, the closed-loop branch chain 3 includes a first drive unit 32, a second drive unit 34, a T-shaped link 33, a parallelogram sub-chain 31, and a driven connecting rod 35. The first link 311 in the parallelogram sub-chain 31 is hinged to the static platform 1 and driven by the first drive unit 32. The parallelogram sub-chain 31 and the driven connecting rod 35 are connected in a rotational kinematic joint via the third link 313 of the parallelogram sub-chain 31. The other side of the driven connecting rod 35 is connected to the moving platform 2 via a ball kinematic joint 37.

[0046] like Figure 5 and Figure 6 As shown, the two ends of the first link 311 of the parallelogram sub-chain 31 are respectively connected to the second link 312 and the fourth link 314. In this embodiment, the length of the second link 312 is the same as the length of the fourth link 314, the length of the first link 311 is the same as the length of the third link 313, the length of the second link 312 is greater than the length of the first link 311, and the two ends of the first link 311 are respectively connected to the second link 312 and the fourth link 314. The column in the middle of the T-shaped link 33 is hinged to the static platform 1.

[0047] like Figure 2 、 Figure 3 as well as Figure 6 As shown, the transmission mechanism 36 in this embodiment includes a driving gear 361 and a driven sector gear 362. The driving gear 361 is coaxially arranged with the output shaft of the second drive unit 34. The driven sector gear 362 is meshed and connected to the driving gear 361 and is mounted on the vertical rod of the T-shaped connecting rod 33. The driven sector gear 362 drives the parallelogram branch chain to rotate along the vertical rod of the T-shaped connecting rod 33. The transmission ratio n between the driving gear 361 and the driven sector gear 362, and the sector angle a of the driven sector gear 362, where n = 5-10 and a = 90°-120°, can drive the dynamic platform to achieve translation and rotation at different speeds within the workspace that meets the requirements of the corresponding surgical procedure.

[0048] It should be further explained that in this embodiment, the transmission ratio n = 5 and the sector angle a = 90°. The transmission ratio and sector angle can be adjusted according to the range of movement of the parallelogram sub-chain 31 and are not absolutely limited here. The end of the power output shaft of the second drive unit 34 is fixedly connected to the driving gear 361 in the transmission mechanism 36, and the driven sector gear 362 is mounted in the middle of the T-shaped connecting rod 33. The driving gear 361 and the driven sector gear 362 are meshed with each other. When the second drive unit 34 is operating, the driving gear 361 drives the driven sector gear 362 to perform a certain range of circular motion around the center of the driven sector gear 362, thereby causing the first height of the parallelogram sub-chain 31 to increase or decrease, thereby outputting power.

[0049] Based on the above-mentioned method of using a surgical parallel mechanism, including the X-axis translation method, Y-axis translation method, Z-axis translation method, X-axis rotation method, Y-axis rotation method and Z-axis rotation method of the moving platform 2, wherein,

[0050] X-axis translation method: Simultaneously start the first drive units 32 on the left and right sides of the static platform 1 to drive the parallelogram sub-chain 31 to move, thereby driving the dynamic platform 2 to translate along the X-axis direction through the driven connecting rod 35;

[0051] Y-axis translation method: Start the first driving unit 32 on one side of the static platform 1, and drive the dynamic platform 2 to translate along the Y-axis direction by changing the posture of the closed-loop branch chain 3 on one side of the static platform 1;

[0052] Z-axis translation method: Simultaneously start the first drive unit 32 at the bottom of the static platform 1 and the second drive units 34 on the left and right sides of the static platform 1, and drive the dynamic platform 2 to translate along the Z-axis through the parallelogram sub-chain 31 and the driven connecting rod 35;

[0053] X-axis rotation method: start the second driving unit 34 on one side of the left and right sides of the static platform 1, and drive the dynamic platform 2 to rotate along the X-axis through the parallelogram sub-chain 31 and the driven connecting rod 35;

[0054] Y-axis rotation method: start the first driving unit 32 at the bottom of the static platform 1, and drive the dynamic platform 2 to rotate along the Y-axis through the parallelogram sub-chain 31 and the driven connecting rod 35;

[0055] Z-axis rotation method: start the second driving units 34 on both sides of the static platform 1, and drive the dynamic platform 2 to rotate along the Z-axis by changing the height h1 of the parallelogram sub-chain 31.

[0056] An orthopedic surgical robot employing the aforementioned parallel mechanism comprises a trolley, an orthopedic surgical module for orthopedic surgery, and the aforementioned surgical parallel mechanism. The parallel mechanism comprises a static platform 1 fixedly mounted on the trolley, and the orthopedic surgical module fixedly mounted on a dynamic platform 2 of the parallel mechanism. The robot also includes a force sensing module mounted on the dynamic platform 2 for real-time data detection.

[0057] The modular orthopedic surgical robot of the present invention has a parallel configuration and its two ends can be equipped with force sensors and modular end-tools for loading. The modular end-tools include, but are not limited to, bone grinding modules, bone saw modules, bone drill modules, bone milling modules, osteotomy guide modules, bone drilling catheter modules, and ultrasonic acquisition modules, etc., which are specialized instruments for orthopedic surgery. These tools can adapt to the operating space requirements of different orthopedic surgical procedures and can achieve minimally invasive and precise operations in the patient's surgical area through collaboration between the robot and the doctor. Simultaneously, it possesses the advantages of high rigidity and high precision of the parallel configuration. Lightweight materials (such as 7075 aluminum, etc.) are used extensively for its components, and its structural parameters are optimized to achieve high adaptability, load-to-weight ratio, and motion accuracy for the robot's main structure, allowing it to better adapt to orthopedic surgical environments with a smaller size.

[0058] It should be understood that the specific embodiments described above are only used to explain the present invention and are not intended to limit the present invention. Obvious changes or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A parallel mechanism for surgery, characterized in that: It comprises a static platform (1) fixedly mounted on a surgical device, a dynamic platform (2) connected to a surgical module for driving the surgical module to change its posture, and three groups of closed-loop branches (3) rotatably arranged between the static platform (1) and the dynamic platform (2); when the three groups of closed-loop branches (3) are all in their original state, the plane on which the dynamic platform (2) is located is perpendicular to the plane on which the static platform (1) is located; wherein, The closed-loop branched chain (3) comprises: A parallelogram sub-chain (31) is rotatably connected to the static platform (1) via a T-shaped connecting rod (33); A first drive unit (32) is rotatably mounted on the static platform (1), and an output shaft of the first drive unit (32) is coaxially arranged with a vertical rod of the T-shaped connecting rod (33); A second drive unit (34) is fixedly mounted on the parallelogram sub-chain (31) and drives the parallelogram sub-chain (31) to rotate along the output shaft axis of the first drive unit (32) via a transmission mechanism (36); A driven connecting rod (35), one end of which is rotatably mounted on a parallelogram sub-chain (31) away from the static platform (1), and the other end of which is rotatably connected to the dynamic platform (2); The first drive unit (32) and the second drive unit (34) drive the movable platform (2) to perform translation in the X-axis direction, the Y-axis direction, and the Z-axis direction and rotation along the X-axis, the Y-axis, and the Z-axis through the parallelogram sub-chain (31) and the driven connecting rod (35); The static platform (1) and the dynamic platform (2) are both equilateral triangle structures, and the three groups of closed-loop branch chains (3) are all rotatably connected to the corresponding vertex angles of the static platform (1) and the dynamic platform (2); The parallelogram sub-chain (31) comprises a first connecting rod (311), a second connecting rod (312), a third connecting rod (313) and a fourth connecting rod (314) which are sequentially connected end to end to form a parallelogram structure; wherein, The second driving unit (34) is mounted on the first connecting rod (311); the two ends of the crossbar of the T-shaped connecting rod (33) are rotatably connected to the second connecting rod (312) and the fourth connecting rod (314), respectively; and the driven connecting rod (35) is rotatably connected to the second connecting rod (312) and the fourth connecting rod (314) at one end away from the static platform (1).

2. A surgical parallel mechanism according to claim 1, characterized in that: The transmission mechanism (36) comprises: A driving gear (361) is coaxially arranged with the output shaft of the second driving unit (34); The driven sector gear (362) is meshed with the driving gear (361) for transmission connection and is mounted on the vertical rod of the T-shaped connecting rod (33); the driven sector gear (362) drives the parallelogram sub-chain (31) to rotate along the vertical rod of the T-shaped connecting rod (33).

3. A surgical parallel mechanism according to claim 2, characterized in that: The transmission ratio n of the driving gear (361) and the driven fan-shaped gear (362), and the fan-shaped angle a of the driven fan-shaped gear (362), wherein n=5-10, a=90°-120°, can drive the dynamic platform to achieve translation and rotation at different speeds within a workspace that meets the requirements of the corresponding surgical procedure.

4. The surgical parallel mechanism according to claim 1, characterized in that: The three driven connecting rods (35) are all rotationally connected to the moving platform (2) via a ball motion pair (37) S.

5. The surgical parallel mechanism according to claim 1, characterized in that: Lifting ears (11) extend from the top corners on both sides and the bottom top corner of the static platform (1), and the closed-loop branch chain (3) is hinged to the static platform (1) via the lifting ears (11). The static platform (1) and the closed-loop branch chain (3) form a rotational motion pair R.

6. A method for using the surgical parallel mechanism according to any one of claims 1 to 5, characterized in that: The method includes an X-axis translation method, a Y-axis translation method, a Z-axis translation method, an X-axis rotation method, a Y-axis rotation method, and a Z-axis rotation method of the moving platform (2), wherein: X-axis translation method: simultaneously starting the first driving units (32) on the left and right sides of the static platform (1) to drive the parallelogram sub-chain (31) to move, thereby driving the dynamic platform (2) to translate along the X-axis direction through the driven connecting rod (35); Y-axis translation method: starting the first driving unit (32) on one side of the left and right positions of the static platform (1), and driving the dynamic platform (2) to translate along the Y-axis direction by changing the posture of the closed-loop branch chain (3) on one side of the static platform (1); Z-axis translation method: simultaneously starting the first driving unit (32) at the bottom of the static platform (1) and the second driving units (34) on the left and right sides of the static platform (1), and driving the dynamic platform (2) to translate along the Z-axis direction through the parallelogram sub-chain (31) and the driven connecting rod (35); X-axis rotation method: start the second driving unit (34) on one of the left and right sides of the static platform (1), and drive the dynamic platform (2) to rotate along the X-axis through the parallelogram sub-chain (31) and the driven connecting rod (35); Y-axis rotation method: start the first driving unit (32) at the lower part of the static platform (1), and drive the dynamic platform (2) to rotate along the Y-axis through the parallelogram sub-chain (31) and the driven connecting rod (35); Z-axis rotation method: start the second driving units (34) on both sides of the static platform (1), and drive the dynamic platform (2) to rotate along the Z-axis by changing the height h1 of the parallelogram sub-chain (31).

7. An orthopedic surgical robot, characterized in that: It comprises a trolley, an orthopedic surgery module for orthopedic surgery, and a surgical parallel mechanism according to any one of claims 1 to 4; wherein, The static platform (1) of the parallel mechanism is fixedly mounted on an orthopedic surgery trolley, and the orthopedic surgery module is fixedly mounted on the dynamic platform (2) of the parallel mechanism.

8. The orthopedic surgical robot according to claim 7, characterized in that: It also includes a force sensing module installed on the moving platform (2) for detecting data in real time.

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