Instrument joint assembly and surgical instrument comprising same

Abstract

Disclosed in the present invention are an instrument joint assembly and a surgical instrument comprising same. The instrument joint assembly comprises an active-end component, a connecting component, and a passive-end component that are rotatably connected in sequence and all rotate on a plane in at least one projection direction of the instrument joint assembly. In each projection direction, the instrument joint assembly is provided with one pair of passive cables and one pair of driving cables. Each pair of passive cables separately passes through the active-end component, the connecting component, and the passive-end component along the axial direction and is distributed on two sides of a rotating part. The radius ratio between a first distribution radius of a first hole in the active-end component and a second distribution radius of a second hole in the passive-end component is greater than or less than 1. The instrument joint assembly and the surgical instrument comprising same can compensate for an angle deviation caused by a change in the length of the driving cables or the passive cables between joints during rotation, thereby improving the angular precision of an end joint; alternately, they enable the passive-end component to achieve a larger deviation angle under a smaller drive angle, thereby increasing the range of movement of the end joint.

Description

Instrument joint assembly and surgical instruments including it

[0001] This application claims priority to Chinese patent application 2024112247386, filed on September 2, 2024. The entire contents of the aforementioned Chinese patent application are incorporated herein by reference. Technical Field

[0002] This invention relates to the technical field of surgical robots, and particularly to an instrument joint assembly and a surgical instrument including the same. Background Technology

[0003] With advancements in technology, surgical robot technology has matured and is now widely used. A surgical robot typically includes a manipulator and surgical instruments connected to it. Specifically, the surgical instruments are connected to the manipulator's drive mechanism to perform surgical procedures. The surgical instruments include distal end-effectors that can perform surgical maneuvers at different angles and directions, simulating joint movement to execute the procedures.

[0004] As shown in Figures 1 and 2, to achieve a wider field of view for surgical robots, a larger operational space for end effectors, and more flexible degrees of freedom of movement, existing technologies often employ parallelogram structures for end effectors. This structure allows the parts on both sides of the parallelogram to maintain a near-parallel spatial geometric relationship during movement. Its main features and principles are as follows: the active end part 2, connecting part 3, and passive end part 4 are connected by hinges or other connection methods to achieve flexible rotational freedom. Two passive ropes 5 of equal length pass through the three parts, and their ends are fixedly connected to the active end part 2 and passive end part 4 by pressing or welding, respectively, ensuring that the two passive ropes 5 are parallel in their initial positions and maintain a certain preload. At this point, the two passive ropes 5, together with the active end part 2 and passive end part 4, form a parallelogram structure. One end of the drive rope 6 is fixedly connected to the connecting part 3 (or passive end part 4). When the connecting part 3 is driven by the drive rope 6 and rotates relative to the active end part 2, due to the geometric characteristics of the parallelogram, the active end part 2 and passive end part 4 always maintain a relatively parallel geometric relationship.

[0005] However, due to the change in the length of the rope between the joints during the movement, the passive end part 4 and the active end part 2 are not theoretically completely parallel, and their angular deviation will increase as the driving angle increases, which seriously affects the angular accuracy of the surgical robot's end joint (i.e., the passive end part 4).

[0006] Therefore, although existing technologies mostly employ parallel mechanisms based on parallelogram structures (as shown in Figures 3 and 4), in reality, the passive end part 4 and the active end part 2 are not completely parallel; the angle between them is a deviation angle. The reason is as follows: As shown in Figure 5, taking the upward movement of the passive end joint (corresponding to the passive end part 4) as an example, the exposed active end segment 521 of the second passive rope 52 reaches a certain position due to traction, lengthening to a certain dimension. However, since the elastic deformation of the rope is negligible, its length remains constant. Theoretical calculations show that the shortened dimension of the exposed passive end segment 522 is shorter than the lengthened dimension of the exposed active end segment 521. Therefore, the passive end part 4 cannot move to a parallel position, resulting in an angular deviation between it and the active end part 2. When the limiting angle (the limiting angle refers to the angle formed by the relative surfaces of the active end part 2 and the connecting part 3 at the connection point when the rotation angle of the connecting part 3 relative to the active end part 2 is zero) is a certain design value α, the theoretical deviation angle of the passive end part 4 varies with the driving angle as shown in Figure 6 (negative values ​​represent outward deviation). As can be seen from Figure 6, for the instrument joint assembly with a parallelogram structure, within the driving angle range of 0 to α°, the deviation angle gradually increases with the increase of the driving angle, and the growth rate (the growth rate refers to the rate at which the deviation angle increases with the driving angle, i.e., the rate at which the deviation angle increases) also gradually increases. When the driving angle continues to gradually increase to approach the limiting angle, the deviation angle even exceeds 15°. This problem seriously affects the rotation angle accuracy and movement flexibility of the instrument joint assembly, restricting and inconveniencing the operator's field of vision and operational freedom during surgery, affecting the safety and effectiveness of surgical instruments, and even affecting surgical efficiency and success rate. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the defects of poor angular accuracy and motion flexibility of the end joints of surgical robots in the prior art, and to provide an instrument joint assembly and a surgical instrument including the same.

[0008] The present invention solves the above-mentioned technical problems through the following technical solution:

[0009] A device joint assembly includes an active end part, a connecting part, and a passive end part that are rotatably connected in sequence, wherein the active end part, the connecting part, and the passive end part all rotate in a plane in at least one projection direction of the device joint assembly.

[0010] In each projection direction, the instrument joint assembly is provided with at least one pair of passive ropes and at least one pair of drive ropes; each pair of passive ropes includes two passive ropes, which pass through the active end part, the connecting part, and the passive end part axially, respectively, and both ends of each passive rope are fixed to the active end part and the passive end part, respectively, and the two passive ropes are distributed on both sides of the rotating part between the active end part, the connecting part, and the passive end part; each pair of drive ropes includes two drive ropes, which are distributed on both sides of the rotating part, and one end of each drive rope is fixed to the connecting part or the passive end part;

[0011] The active end component has at least one first hole for the passive rope to pass through axially, and the passive end component has at least one second hole for the passive rope to pass through axially. The vertical distance from the center of the first hole to the axis of the active end component is a first distribution radius, and the vertical distance from the center of the second hole to the axis of the passive end component is a second distribution radius. The ratio of the first distribution radius to the second distribution radius is greater than or less than 1.

[0012] In this design, the joint assembly of the surgical robot is driven by two drive ropes and pulled by a passive rope, causing the passive end component to rotate relative to the connecting component. Simultaneously, the connecting component rotates relative to the active end component, allowing the passive end component to rotate at different angles relative to the active end component to perform surgical operations. By using different distribution radii, the radius ratio can be greater than or less than 1. When the radius ratio is greater than 1, the two passive ropes, the active end component, and the passive end component form a trapezoidal structure, which can compensate for the angular deviation caused by changes in the length of the drive or passive ropes between the joints during rotation, bringing it close to or equal to the target angle, thereby improving the angular accuracy of the surgical robot's end joint. When the radius ratio is less than 1, the two passive ropes, the active end component, and the passive end component form an inverted trapezoidal structure, allowing the passive end component (representing the passive joint) to achieve a larger deviation angle at a smaller drive angle during rotation. This is beneficial for the connecting component to increase the activity angle of the passive end component even under specific constraints, thus improving the mobility of the end joint.

[0013] Preferably, the radius ratio is determined by the equation Sure;

[0014] Wherein, K is the radius ratio, α is the initial angle formed between the relative surfaces of the active end part and the connecting part at the connection point when the rotation angle of the connecting part relative to the active end part and the passive end part is zero, and the initial angle between the active end part and the connecting part is equal to the initial angle between the passive end part and the connecting part; β1 is the driving angle of the rotation of the connecting part relative to the active end part; Δβ is the deviation angle of the axis of the passive end part relative to the axis of the active end part when the passive end part is rotated.

[0015] In this scheme, the joint assembly of the device determines the radius ratio K using the aforementioned equation, ensuring that the angle of the passive end component is compensated to or close to the target angle, thus improving the accuracy of angle compensation. Specifically, the initial angle between the active end component and the connecting component is equal to the initial angle between the passive end component and the connecting component. This setting reduces the complexity of calculating and determining the K value, eliminating the need to consider the difference between the two initial angles and further supplement the angle deviation, thereby improving the accuracy of the K value. A suitable deviation angle Δβ is selected based on the target angle, thereby determining the K value. The sizes of the two distribution radii are then adjusted according to the K value, ensuring that the actual rotation angle generated by the passive end component is close to the target angle, further improving the accuracy of angle compensation.

[0016] Preferably, the connecting part has a third hole relative to the first hole and a fourth hole relative to the second hole at both ends. The perpendicular distance from the center of the third hole to the axis of the connecting part is a third distribution radius, and the perpendicular distance from the center of the fourth hole to the axis of the connecting part is a fourth distribution radius.

[0017] The third distribution radius is equal to the first distribution radius, and / or the fourth distribution radius is equal to the second distribution radius.

[0018] In this scheme, when the third distribution radius is equal to the first distribution radius, the first exposed segment of the passive rope between the connecting part and the active end part is horizontal, which facilitates the determination of the first exposed segment based on the first distribution radius and the initial angle α, and makes it easier to calculate the K value. When the fourth distribution radius is equal to the second distribution radius, the second exposed segment of the passive rope between the connecting part and the passive end part is horizontal, which facilitates the determination of the second exposed segment based on the second distribution radius and the initial angle α, and makes it easier to calculate the K value. This reduces the complexity of the equation for determining the K value and improves the accuracy of angle compensation.

[0019] Preferably, each pair of drive ropes is symmetrically distributed relative to the rotating part.

[0020] In this design, each pair of drive ropes is symmetrically distributed relative to the rotating part, which makes it easier to accurately control the drive angle of the connecting parts or the passive end parts compared to an asymmetrical distribution.

[0021] Preferably, each pair of passive ropes is symmetrically distributed relative to the rotating part. In this design, the symmetrical distribution of each pair of passive ropes relative to the rotating part eliminates the difference in radius ratio distribution compared to an asymmetrical distribution, which helps to reduce angular deviation and improve the accuracy of angle compensation. Preferably, the instrument joint assembly has a pair of passive ropes and a pair of drive ropes in at least two different projection directions, and the radius ratios in the two projection directions are equal or unequal.

[0022] In this design, the joint assembly of the device achieves angle compensation in different projection directions by setting a pair of passive ropes and a pair of drive ropes in two different projection directions. When the radius ratios in the two different projection directions are equal, angle compensation can be performed sequentially in the different projection directions; when the radius ratios in the two different projection directions are unequal, angle compensation in both directions can be combined to achieve adjustment within a larger angle range and improve the degree of freedom of rotation.

[0023] Preferably, the two projection directions are perpendicular to each other.

[0024] In this scheme, the two projection directions are perpendicular to each other, which facilitates the arrangement of rotating components in the two projection directions.

[0025] Preferably, the rotating part includes at least one first rotating part between the active end part and the connecting part, and at least one second rotating part between the passive end part and the connecting part;

[0026] The first rotating part has two first rotating shafts in the projection direction at both ends along the axial direction, and the body of the first rotating part is connected to the active end part and the connecting part respectively through the two first rotating shafts; and / or, the second rotating part has two second rotating shafts in the projection direction at both ends along the axial direction, and the body of the second rotating part is connected to the passive end part and the connecting part respectively through the two second rotating shafts.

[0027] In this design, the active end component and the connecting component can rotate in two different projection directions through a first rotating part. When the number of first rotating parts is greater than one, the active end component and the connecting component can also rotate in more projection directions, achieving more flexible rotational degrees of freedom. Similarly, the passive end component and the connecting component can rotate in two different projection directions through a second rotating part. When the number of second rotating parts is greater than one, the passive end component and the connecting component can also rotate in more projection directions, achieving even more flexible rotational degrees of freedom.

[0028] Preferably, the two first rotation axes in the two projection directions are perpendicular to each other, and the two second rotation axes in the two projection directions are perpendicular to each other.

[0029] In this design, the joint assembly of the device adopts the aforementioned rotating part with two rotating axes. The two first rotating axes and the two second rotating axes are perpendicular to each other, which facilitates the arrangement of the two rotating axes and makes the rotating part easy to process and manufacture.

[0030] A surgical instrument comprising the instrument joint assembly as described above.

[0031] In this design, the surgical instrument adjusts the ratio of the radii of the passive ropes distributed on the active and passive end parts through the aforementioned joint assembly. When the radius ratio is greater than 1, the two passive ropes, the active end part, and the passive end part form a trapezoidal structure, which can compensate for the angular deviation caused by the change in length of the drive rope or passive rope between the joints during rotation, making it close to or equal to the target angle, thereby improving the angular accuracy of the surgical robot's end joint. When the radius ratio is less than 1, the two passive ropes, the active end part, and the passive end part form an inverted trapezoidal structure, which allows the passive end part (representing the passive joint) to obtain a larger deviation angle at a smaller drive angle during rotation. This is beneficial for the connecting parts to increase the activity angle of the passive end part even under specific restrictive environments, thus improving the motion flexibility of the end joint.

[0032] The positive and progressive effects of this invention are as follows: the joint assembly of the device and the surgical instruments including it, by adjusting the ratio of the radii of the passive ropes distributed on the active end part and the passive end part, when the radius ratio is greater than 1, the two passive ropes, the active end part, and the passive end part form a trapezoidal structure, which can compensate for the angular deviation caused by the change in length of the drive rope or passive rope between the joints during rotation, making it close to or equal to the target angle, thereby improving the angular accuracy of the end joint of the surgical robot; when the radius ratio is less than 1, the two passive ropes, the active end part, and the passive end part form an inverted trapezoidal structure, which allows the passive end part (representing the passive joint) to obtain a larger deviation angle at a smaller drive angle during rotation, which is beneficial for the connecting parts to increase the activity angle of the passive end part even under specific restrictive environments, that is, to improve the motion flexibility of the end joint. Attached Figure Description

[0033] Figure 1 is a schematic diagram of the structure of the joint assembly of the prior art, which is a parallelogram structure and is located in the initial position.

[0034] Figure 2 is a schematic diagram of the structure of the joint assembly of the prior art, which is a parallelogram structure and rotates.

[0035] Figure 3 is a schematic diagram of the structure of the joint assembly of the prior art, which is a parallelogram structure and is located in the initial position.

[0036] Figure 4 is a schematic diagram of the ideal rotation angle of the joint assembly of the prior art, which is a parallelogram structure.

[0037] Figure 5 is a schematic diagram of the actual rotation angle of the joint assembly of the prior art, which is a parallelogram structure.

[0038] Figure 6 shows the curve of the theoretical deviation angle of the joint assembly of the device in the prior art as a function of the driving angle.

[0039] Figure 7 is a schematic diagram of the structure of the joint assembly of the instrument in the initial position in Embodiment 1 of the present invention.

[0040] Figure 8 is a schematic diagram of the structure of the joint assembly of the device in Embodiment 1 of the present invention when it rotates.

[0041] Figure 9 is a three-dimensional structural diagram of the joint assembly of the device in the initial position in Embodiment 1 of the present invention.

[0042] Figure 10 is a three-dimensional structural diagram of the joint assembly of the device in Embodiment 1 of the present invention in one projection direction.

[0043] Figure reference numerals: 1. Joint assembly; 2. Active end component; 3. First hole; 4. First distribution radius R1; 5. Connecting component; 6. Third hole; 7. Fourth hole; 8. Passive end component; 9. Second hole; 10. Second distribution radius R2; 11. Projection direction A, B; 11. Passive rope; 12. First passive rope; 13. Second passive rope; 14. Exposed active end segment; 15. Exposed passive end segment; 16. First exposed segment l1 in initial position; 17. Second exposed segment l2 in initial position; 18. First exposed segment l′1 during rotation; 19. Second exposed segment l′2 during rotation; 10. Drive rope; 11. First drive rope; 12. Second drive rope; 13. Rotating part; 14. First rotating part; 15. First rotating shaft; 16. Second rotating part; 17. Second rotating shaft; 18. Detailed Implementation

[0044] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0045] Example 1

[0046] This embodiment provides an instrument joint assembly 1 for use in a surgical robot, which is installed at the end of a surgical instrument, as shown in Figures 7-10. The instrument joint assembly 1 includes an active end part 2, a connecting part 3, and a passive end part 4 that are rotatably connected in sequence, and the active end part 2, the connecting part 3, and the passive end part 4 all rotate on a plane in at least one projection direction of the instrument joint assembly 1.

[0047] In each projection direction, the instrument joint assembly 1 is provided with at least one pair of passive ropes 5 and at least one pair of drive ropes 6; each pair of passive ropes 5 includes two passive ropes 5, which pass through the active end part 2, the connecting part 3 and the passive end part 4 respectively along the axial direction, and the two ends of each passive rope 5 are fixed to the active end part 2 and the passive end part 4 respectively, and the two passive ropes 5 are distributed on both sides of the rotating part 7 between the active end part 2, the connecting part 3 and the passive end part 4; each pair of drive ropes 6 includes two drive ropes 6, which are distributed on both sides of the rotating part 7, and one end of each drive rope 6 is fixed to the connecting part 3 or the passive end part 4.

[0048] The active end part 2 has at least one first hole 21 for the passive rope 5 to pass through along the axial direction, and the passive end part 4 has at least one second hole 41 for the passive rope 5 to pass through along the axial direction. The vertical distance from the center of the first hole 21 to the axis of the active end part 2 is the first distribution radius R1, and the vertical distance from the center of the second hole 41 to the axis of the passive end part 4 is the second distribution radius R2. The radius ratio K of the first distribution radius R1 to the second distribution radius R2 is greater than or less than 1.

[0049] Specifically, in this embodiment, the passive end component 4 corresponds to the distal joint during surgery. The active end component 2, the connecting component 3, and the passive end component 4 all rotate in the planes of the two projection directions A and B of the instrument joint assembly 1. That is, the trapezoidal structure of this embodiment is adopted in both projection directions A and B. The specific form of the trapezoidal structure is as follows: a pair of passive ropes 5 includes a first passive rope 51 located above and a second passive rope 52 located below, as shown in Figure 7. The two ends of the two passive ropes 5 are fixed to the active end component 2 and the passive end component 4 respectively by means of crimping or welding. Since the first distribution radius R1 of the first hole 21 on the active end component 2 and the second distribution radius R2 of the second hole 41 on the passive end component 4 are not equal, when the two passive ropes 5 pass through, the two passive ropes 5 form a trapezoidal structure with the active end component 2 and the passive end component 4, rather than a parallelogram structure. When the ratio K of the first distribution radius R1 to the second distribution radius R2 is greater than 1, it is a positive trapezoidal structure; when the ratio K of the first distribution radius R1 to the second distribution radius R2 is less than 1, it is an inverted trapezoidal structure. This embodiment uses a positive trapezoidal structure. In other embodiments, if it is desired that the passive end part (representing the passive joint) can obtain a larger deviation angle under a smaller angle of drive, an inverted trapezoidal structure can also be used. Furthermore, depending on the needs of the surgical operation, the three parts of the instrument joint assembly 1 can rotate only in one projection direction plane, or rotate in multiple projection direction planes, to achieve greater rotational freedom. The above-mentioned trapezoidal structure can be present in each projection direction.

[0050] In this embodiment, the two passive ropes 5 maintain a certain preload in their initial position (also known as the zero position, i.e., when the rotation angle of the connecting part 3 relative to both the active end part 2 and the passive end part 4 is zero). A pair of drive ropes 6 includes a first drive rope 61 located above and a second drive rope 62 located below (same as the drive rope 6 in the prior art shown in Figure 1). The two drive ropes 6 are distributed on both sides of the drive unit 7. One end of each drive rope 6 is fixed to the connecting part 3 by crimping or welding, and the other end is connected to the drive device of the surgical robot (not shown in the figure). In other embodiments, the end of the drive rope 6 used for fixed connection to the connecting part 3 can also be fixed to the passive end part 4.

[0051] The surgical robot's instrument joint assembly 1 is driven by two drive ropes 6 and pulled by passive ropes 5, causing the passive end part 4 to rotate relative to the connecting part 3. Simultaneously, the connecting part 3 rotates relative to the active end part 2, thus enabling the passive end part 4 to rotate at different angles relative to the active end part 2 to perform surgical operations. By employing different distribution radii, the radius ratio K is made greater than or less than 1. When the radius ratio is greater than 1, the two passive ropes 5, the active end part 2, and the passive end part 4 form a positive trapezoid, i.e., R1 is greater than R2. This positive trapezoidal structure can compensate for the angular deviation caused by the change in length of the drive ropes 6 or passive ropes 5 between the joints during rotation, making it close to or equal to the target angle, thereby improving the angular accuracy of the surgical robot's end joint. When the radius ratio is less than 1, the two passive ropes 5, the active end part 2, and the passive end part 4 form an inverted trapezoidal structure, that is, R1 is less than R2. This inverted trapezoidal structure allows the passive end part (representing the passive joint) to obtain a larger deviation angle at a smaller driving angle during rotation. This is beneficial for the connecting part 3 to increase the activity angle of the passive end part 4 even under specific restrictive environments (that is, the connecting part 3 can only rotate within a small angle range under certain specific restrictive environments), thus improving the motion flexibility of the end joint.

[0052] In this embodiment, the radius ratio K is given by the equation Sure.

[0053] Where K is the radius ratio, α is the initial angle formed between the relative surfaces of the active end part 2 and the connecting part 3 at the connection point when the rotation angle of the connecting part 3 relative to the active end part 2 and the passive end part 4 is zero, and the initial angle between the active end part 2 and the connecting part 3 is equal to the initial angle between the passive end part 4 and the connecting part 3; β1 is the driving angle of the rotation of the connecting part 3 relative to the active end part 2; Δβ is the deviation angle of the axis of the passive end part 4 relative to the axis of the active end part 2 when the passive end part 4 is rotated.

[0054] The principle behind the above equation is: K is the ratio of the first distribution radius R1 to the second distribution radius R2, i.e., K = R1 / R2; when the joint assembly is in the zero position, the hard limit angle of joint rotation is α (this hard limit angle is the initial included angle), since Therefore:

[0055] Similarly

[0056] The total length l0 of the line segments exposed at the joint is:

[0057] When the connecting part 3 of the joint assembly 1 of the device is driven to form an angle β1 with the active end part 2, the changed result can be obtained.

[0058] Since the length of the second passive rope 52 remains unchanged before and after the rotation, that is, the length of the line segment l0 exposed at the joint remains unchanged, therefore: l′2=l0-l′1;

[0059] From the geometric relationships after rotation, we obtain:

[0060] Therefore:

[0061] Furthermore, from the geometric relationship after rotation, the rotation angle β2 = α - γ relative to the connecting part 3 is obtained, where γ is the angle formed by the relative surfaces of the passive end part 4 and the connecting part 3 at the connection point when the passive end part 4 is rotated. Finally, the deviation angle Δβ = β2 - β1 of the passive end part 4 relative to the active end part 2 is...

[0062] Combining the above equations, we can finally obtain the relationship between the deviation angle Δβ and the hard limit angle (i.e., the initial angle) α of the part, the parameter K, and the driving angle β1:

[0063] Based on this equation for Δβ, the equation for the above K value can be obtained through transformation.

[0064] In other embodiments, the initial angle between the active end part 2 and the connecting part 3 is a1, and the initial angle between the passive end part 4 and the connecting part 3 is a2. a1 and a2 may differ slightly and are not necessarily exactly equal. However, this setting is less efficient than setting the two initial angles to be equal in this embodiment, as it reduces the complexity of the equation and makes it easier to calculate a K value close to the target angle. In other embodiments, the above equation can also be used to obtain the K value. A reasonable K value can be obtained by gradually adjusting the sizes of the first distribution radius R1 and the second distribution radius R2. However, this is less efficient than the embodiment where the joint assembly 1 determines the radius ratio K using the above equation, allowing the angle of the passive end part 4 to be compensated to or closer to the target angle, thus improving the accuracy of angle compensation. Specifically, the initial angle between the active end part 2 and the connecting part 3 is equal to the initial angle between the passive end part 4 and the connecting part 3. This setting reduces the complexity of calculating and determining the K value, eliminating the need to consider the difference between the two initial angles and further supplement the angle deviation, thereby improving the accuracy of the K value. Select a suitable deviation angle Δβ based on the target angle, thereby determining the K value. Adjust the size of the two distribution radii according to the K value so that the actual rotation angle generated by the passive end part 4 is close to the target angle, thus improving the accuracy of angle compensation.

[0065] The driving angle β1 ranges from 0° to 30°. By determining the K value using the driving angle within this range, the theoretical angle deviation can be reduced, further improving the accuracy of angle compensation.

[0066] The connecting part 3 has a third hole 31 at both ends relative to the first hole 21 and a fourth hole 32 relative to the second hole 41. The vertical distance from the center of the third hole 31 to the axis of the connecting part 3 is the third distribution radius, and the vertical distance from the center of the fourth hole 32 to the axis of the connecting part 3 is the fourth distribution radius. The third distribution radius is equal to the first distribution radius R1, and the fourth distribution radius is equal to the second distribution radius R2.

[0067] When the third distribution radius is equal to the first distribution radius R1, the first exposed segment l1 of the passive rope 5 between the connecting part 3 and the active end part 2 is horizontal, which facilitates the determination of the first exposed segment l1 based on the first distribution radius R1 and the initial angle α, and makes it easier to calculate the K value; when the fourth distribution radius is equal to the second distribution radius R2, the second exposed segment l2 of the passive rope 5 between the connecting part 3 and the passive end part 4 is horizontal, which facilitates the determination of the second exposed segment l2 based on the second distribution radius R2 and the initial angle α, and makes it easier to calculate the K value; thus reducing the complexity of the equation for determining the K value and improving the accuracy of angle compensation.

[0068] In other embodiments, the third distribution radius may not be equal to the first distribution radius R1, and the fourth distribution radius may not be equal to the second distribution radius R2. That is, the first exposed line segment l1 and the second exposed line segment l2 are not horizontal. In this case, when calculating l1 and l2, the equations for calculating l1 and l2 are not used as described above. Instead, conversion or other calculation methods are needed to compensate for the values ​​of l1 and l2. However, this method is not convenient for calculating the K value and is not conducive to the accuracy of angle compensation. Therefore, setting the third distribution radius to equal the first distribution radius R1 and the fourth distribution radius to equal the second distribution radius R2 facilitates the calculation of the K value, thereby reducing the complexity of the equation for determining the K value and improving the accuracy of angle compensation.

[0069] In this configuration, each pair of drive ropes 6 and / or each pair of driven ropes 5 are symmetrically distributed relative to the rotating part 7. This symmetrical distribution of each pair of drive ropes 6 and / or each pair of driven ropes 5, compared to an asymmetrical distribution, eliminates the difference in radius ratios, which helps reduce angular deviation and improve the accuracy of angular compensation.

[0070] In this embodiment, the two drive ropes 6 are located inside the two passive ropes 5. In other embodiments, the two drive ropes 6 can also be located outside the two passive ropes 5. Both arrangements allow the connecting part 3 and the passive end part 4 to rotate relative to the active end part 2 through the traction of the two drive ropes 6.

[0071] In this embodiment, the joint assembly 1 is equipped with a pair of passive ropes 5 and a pair of drive ropes 6 in two different projection directions A and B. The radius ratio K in the two projection directions A and B may be equal or unequal. By providing a pair of passive ropes 5 and a pair of drive ropes 6 in both different projection directions, the joint assembly 1 achieves angle compensation in different projection directions. When the radius ratio in the two different projection directions is equal, angle compensation can be performed sequentially in the different projection directions; when the radius ratio in the two different projection directions is unequal, angle compensation in both directions can be combined to achieve adjustment within a larger angle range and improve the degree of freedom of rotation.

[0072] The two projection directions are perpendicular to each other. This perpendicular relationship facilitates the arrangement of the seven rotating parts along the two projection directions.

[0073] As shown in Figures 9 and 10, the rotating part 7 includes at least one first rotating part 71 between the active end part 2 and the connecting part 3, and at least one second rotating part 72 between the passive end part 4 and the connecting part 3; the first rotating part 71 includes two first rotating shafts 711 in the projection direction at both ends along the axial direction, and the body of the first rotating part 71 is connected to the active end part 2 and the connecting part 3 respectively through the two first rotating shafts 711; the second rotating part 72 includes two second rotating shafts 721 in the projection direction at both ends along the axial direction, and the body of the second rotating part 72 is connected to the passive end part 4 and the connecting part 3 respectively through the two second rotating shafts 721.

[0074] The active end component 2 and the connecting component 3 can rotate in two different projection directions through a first rotating part 71. When the number of first rotating parts 71 is greater than one, the active end component 2 and the connecting component 3 can also rotate in more projection directions, achieving more flexible rotational degrees of freedom. The passive end component 4 and the connecting component 3 can rotate in two different projection directions through a second rotating part 72. When the number of second rotating parts 72 is greater than one, the passive end component 4 and the connecting component 3 can also rotate in more projection directions, achieving more flexible rotational degrees of freedom.

[0075] In this structure, the two first rotating shafts 711 are perpendicular to each other in the two projection directions A and B, and the two second rotating shafts 721 are also perpendicular to each other in the two projection directions A and B. This mutual perpendicular relationship makes it easy to arrange the two rotating shafts and also makes the rotating part easy to process and manufacture.

[0076] In other embodiments, if the two projection directions A and B are not perpendicular to each other, the two first rotation axes 711 and the two second rotation axes 721 may also not be perpendicular to each other, but may adopt other angular relationships according to the needs of rotation. Alternatively, when multiple first rotation parts are interconnected or multiple second rotation parts are interconnected, two or more first rotation axes 711 can achieve rotation at more angles, and two or more second rotation axes 721 can also achieve rotation at more angles, thereby increasing the degree of freedom of rotation. Alternatively, other rotation forms can be used to achieve rotation between various parts, for example, using ball bearings to achieve rotation at any angle, further improving the degree of freedom of rotation.

[0077] Example 2

[0078] This embodiment provides a surgical instrument for use in a surgical robot. The surgical instrument includes an instrument joint assembly 1 as described in Embodiment 1. Through the instrument joint assembly 1, the surgical instrument adjusts the ratio of the radii of the passive ropes 5 distributed on the active end part 2 and the passive end part 4. When the radius ratio is greater than 1, the two passive ropes 5, together with the active end part 2 and the passive end part 4, form a trapezoidal structure, which can compensate for the angular deviation caused by the change in length of the drive rope 6 or the passive rope 5 between the joints during rotation, making it close to or equal to the target angle, thereby improving the angular accuracy of the surgical robot's end joint. When the radius ratio is less than 1, the two passive ropes 5, together with the active end part 2 and the passive end part 4, form an inverted trapezoidal structure, which allows the passive end part 4 (representing the passive joint) to obtain a larger deviation angle at a smaller drive angle during rotation. This is beneficial for the connecting part 3 to increase the activity angle of the passive end part even under specific restrictive environments, i.e., increasing the activity angle of the end joint.

[0079] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A device joint assembly, comprising an active end part, a connecting part, and a passive end part rotatably connected in sequence, wherein the active end part, the connecting part, and the passive end part all rotate in a plane in at least one projection direction of the device joint assembly; In each projection direction, the instrument joint assembly is provided with at least one pair of passive ropes and at least one pair of drive ropes; each pair of passive ropes includes two passive ropes, which pass through the active end part, the connecting part, and the passive end part axially, respectively, and both ends of each passive rope are fixed to the active end part and the passive end part, respectively, and the two passive ropes are distributed on both sides of the rotating part between the active end part, the connecting part, and the passive end part; each pair of drive ropes includes two drive ropes, which are distributed on both sides of the rotating part, and one end of each drive rope is fixed to the connecting part or the passive end part; Its features are, The active end component has at least one first hole for the passive rope to pass through axially, and the passive end component has at least one second hole for the passive rope to pass through axially. The vertical distance from the center of the first hole to the axis of the active end component is a first distribution radius, and the vertical distance from the center of the second hole to the axis of the passive end component is a second distribution radius. The ratio of the first distribution radius to the second distribution radius is greater than or less than 1.

2. The joint assembly of the device as described in claim 1, characterized in that, The radius ratio is given by the equation Sure; Wherein, K is the radius ratio, α is the initial angle formed between the relative surfaces of the active end part and the connecting part at the connection point when the rotation angle of the connecting part relative to the active end part and the passive end part is zero, and the initial angle between the active end part and the connecting part is equal to the initial angle between the passive end part and the connecting part; β1 is the driving angle of the rotation of the connecting part relative to the active end part; Δβ is the deviation angle of the axis of the passive end part relative to the axis of the active end part when the passive end part is rotated.

3. The joint assembly of the device as described in claim 1 or 2, characterized in that, The connecting part has a third hole at both ends, corresponding to the first hole, and a fourth hole, corresponding to the second hole. The perpendicular distance from the center of the third hole to the axis of the connecting part is a third distribution radius, and the perpendicular distance from the center of the fourth hole to the axis of the connecting part is a fourth distribution radius. The third distribution radius is equal to the first distribution radius, and / or the fourth distribution radius is equal to the second distribution radius.

4. The joint assembly of the device as described in any one of claims 1-3, characterized in that, Each pair of drive ropes is symmetrically distributed relative to the rotating part.

5. The instrument joint assembly as described in any one of claims 1-4, characterized in that, Each pair of passive ropes is symmetrically distributed relative to the rotating part.

6. The instrument joint assembly as described in any one of claims 1-5, characterized in that, The joint assembly of the device is provided with a pair of passive ropes and a pair of drive ropes in at least two different projection directions, and the ratio of the radii in the two projection directions is equal or unequal.

7. The joint assembly of the device as described in claim 6, characterized in that, The two projection directions are perpendicular to each other.

8. The device joint assembly as described in claim 6 or 7, characterized in that, The rotating part includes at least one first rotating part between the active end part and the connecting part, and at least one second rotating part between the passive end part and the connecting part; The first rotating part has two first rotating shafts in the projection direction at both ends along the axial direction, and the body of the first rotating part is connected to the active end part and the connecting part respectively through the two first rotating shafts; and / or, the second rotating part has two second rotating shafts in the projection direction at both ends along the axial direction, and the body of the second rotating part is connected to the passive end part and the connecting part respectively through the two second rotating shafts.

9. The joint assembly of the device as described in claim 8, characterized in that, The two first rotation axes in the two projection directions are perpendicular to each other, and the two second rotation axes in the two projection directions are perpendicular to each other.

10. A surgical instrument, characterized in that, The surgical instrument includes the instrument joint assembly as described in any one of claims 1-9.

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