Decoupling type four-degree-of-freedom force feedback mechanism for laparoscopic surgery operation

Abstract

The invention relates to the field of force feedback mechanisms, in particular to a decoupling type four-degree-of-freedom force feedback mechanism for laparoscopic surgery operation, which comprises a static platform, a left side branch chain, a right side branch chain, a movable platform, a supporting square tube, a feeding torque motor, a rotating torque motor and an operating handle, the left side branch chain comprises a left branch chain crankshaft, a left branch chain torque motor and a first short shaft, the left branch chain torque motor is fixedly installed on the static platform, one side of the left branch chain crankshaft is rotationally connected to the static platform, and the left branch chain torque motor is in driving connection with the left branch chain crankshaft through a gear and / or a rope wheel mechanism. According to the invention, through detection and calculation of torque motor rotation angle and speed parameters corresponding to all four-degree-of-freedom motion parameters of the working rotating shaft, force feedback pose detection of large-range three-direction centering rotation motion and longitudinal sliding motion can be realized.

Description

Technical Field

[0001] The present invention relates to the field of force feedback mechanisms, and in particular to a decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery. Background Art

[0002] Laparoscopic surgery is gaining popularity among patients and medical institutions due to its advantages, such as minimal incision, short operating time, and rapid recovery. In recent years, laparoscopic surgical technology and related equipment have made significant progress, while the demand for laparoscopic surgical personnel has increased year by year. This has necessitated the training of more qualified laparoscopic surgical personnel in a short period of time. To meet this demand, laparoscopic surgery simulation systems have emerged. Typical laparoscopic surgery simulation systems require a force feedback system to create a virtual surgical environment as realistically as possible. This requires the mechanical structure of the force feedback system to be as simple as possible to facilitate software monitoring and control. Furthermore, the mechanical structure of the force feedback system must be as compact as possible, with sufficient flexibility and a large range of motion to meet actual operational requirements.

[0003] Currently, most manipulators in laparoscopic surgery simulation systems with force feedback on the market utilize a simple serial structure. Due to mechanical limitations, their practical range of motion is limited. For example, adding drive structures such as torque motors to each joint increases the size and weight of the force feedback mechanism. The increased mass of its moving parts further reduces the operator's force perception, thus compromising training effectiveness. The mechanical motion of a laparoscopic surgery simulation system must provide three-dimensional rotational capabilities with distal "centering" and a wide range of rotation. This wide range of motion is essential not only for the surgical field of view but also for the surgical procedure. Laparoscopic surgery is a minimally invasive procedure, requiring a compact, simple, and compact structure. Therefore, considering the typical motion patterns of laparoscopic surgery, there is an urgent need for a decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery that meets the requirements for distal "centering," a wide range of motion, and compact posture adjustment. This mechanism can achieve three-dimensional rotational movement with centering and longitudinal sliding motion through the centering point. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the shortcomings of the existing technology and provide a decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery, which can realize three-rotation centering and a large range of movement, while meeting the requirements of simple and compact structure and operational performance, and can be used in the field of robotic medical care to facilitate mass production, reduce production costs, and improve the work efficiency of medical workers.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solutions. The present invention discloses a decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery, comprising a static platform, a left branch chain, a right branch chain, a dynamic platform, a supporting square tube, a feed torque motor, a rotation torque motor and an operating handle. The static platform is equipped with a left branch chain and a right branch chain, the left branch chain comprises a left branch chain crankshaft, a left branch chain torque motor and a first short shaft, the left branch chain torque motor is fixedly mounted on the static platform, one side of the left branch chain crankshaft is rotationally connected to the static platform, the left branch chain torque motor is driven and connected to the left branch chain crankshaft through a gear and / or a pulley mechanism, the other side of the left branch chain crankshaft is rotationally connected to the first short shaft, and the axes of the two rotating shafts on both sides of the left branch chain crankshaft intersect at a point in space; the right branch chain It includes a right branch chain crankshaft, a right branch chain torque motor and a second short shaft, the right branch chain torque motor is fixedly installed on the static platform, one side of the right branch chain crankshaft is rotatably connected to the static platform, the right branch chain torque motor is driven and connected to the right branch chain crankshaft through a gear and / or a pulley mechanism, and the other side of the right branch chain crankshaft is rotatably connected to the short shaft b; the supporting square tube is slidingly connected to the moving platform, the feed torque motor is fixedly installed on the moving platform, the feed torque motor is driven and connected to the supporting square tube through a wheel rope and / or a gear rack mechanism to achieve longitudinal movement and provide driving force, the rotating torque motor is fixedly installed on the supporting square tube, the operating handle is rotatably connected to the supporting square tube, and the rotating torque motor is driven and connected to the operating handle through a pulley and / or gear mechanism to achieve rotation and provide driving torque.

[0006] Furthermore, the short shaft a is rotatably connected to the moving platform and the rotation axis passes through the intersection of the rotation shaft axes on both sides of the left branch crankshaft, and the short shaft b is fixedly connected to the moving platform.

[0007] Furthermore, the axes of the two rotating shafts on both sides of the right branch chain crankshaft intersect at one point and coincide with the intersection of the axes of the left branch chain. The dynamic platform can realize two-degree-of-freedom rotation around the intersection point under the drive of the left branch chain torque motor and the right branch chain torque motor.

[0008] Furthermore, the left chain torque motor, the right chain torque motor, the feed torque motor and the rotation torque motor are all provided with encoders for relative parameter detection, and the detection objects of the encoders include rotation angle, position and speed motion parameters.

[0009] Furthermore, the right torque motor, left torque motor, feed torque motor and rotation torque motor are provided with a torque instruction module, which is used to feedback an operation feedback force of a specific direction and a specific magnitude to the operator by sending a specific torque instruction.

[0010] Furthermore, one side of the left branch chain crankshaft is fixedly connected to a left branch chain semicircular rope pulley, and the left branch chain semicircular rope pulley is rotatably connected to the static platform. The left branch chain torque motor is connected to the left branch chain crankshaft through the left branch chain semicircular rope pulley to realize wheel rope torque drive; one side of the right branch chain crankshaft is fixedly connected to a right branch chain semicircular rope pulley, and the right branch chain semicircular rope pulley is rotatably connected to the static platform. The right branch chain torque motor is connected to the right branch chain crankshaft through the right branch chain semicircular rope pulley to realize wheel rope torque drive.

[0011] Furthermore, the movable platform includes a movable platform body and a square tube support frame. The movable platform body is fixedly installed with a feed friction wheel support frame. The feed friction wheel support frame is installed with a feed friction large wheel, a first feed friction small wheel and a second feed friction small wheel that are in contact with the supporting square tube. The feed friction large wheel is connected to the feed rope pulley, the square tube support frame and the feed friction wheel support frame, and the supporting square tube is slidably connected to the square tube support frame.

[0012] Furthermore, the feed torque motor is connected to a feed motor support frame, the feed motor support frame is rotatably connected to a third rotating shaft, and the third rotating shaft is connected to the feed rope pulley.

[0013] Furthermore, the rotating torque motor is provided with a rotating motor support frame, the rotating motor support frame is provided with a sleeve, the sleeve is rotatably connected to a rotating sheave, the rotating motor support frame is fixedly connected to the supporting square tube through the sleeve, the rotating motor support frame is installed with a fourth rotating shaft through a rotating pair, and the fourth rotating shaft is connected to the rotating sheave rope.

[0014] The working principle of the present invention is: after the operator manually drags the operating handle, on the one hand, the working shaft of the operating handle rotates, driving the rotating pulley to rotate, and finally mapping the rotational freedom of the operating handle to the rotation of the rotating torque motor; on the other hand, the operating handle longitudinally feeds and drives the supporting square tube to longitudinally feed, thereby driving the feed friction wheel to rotate, and then driving the feed pulley to rotate, and finally mapping the longitudinal feed freedom of the operating handle to the rotation of the feed torque motor; finally, the movement of the operating handle drives the moving platform to move, and then drives the two branch chain semicircular pulleys to rotate, and finally maps the two-degree-of-freedom posture motion of the moving platform to the rotation of the two torque motors fixed to the static platform.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The present invention detects and calculates the torque motor angle and speed parameters corresponding to the motion parameters of all four degrees of freedom of the working shaft, and can realize force feedback posture detection of a large range of three-way centering rotation motion and longitudinal sliding motion; the present invention adopts a parallel structure that integrates rotation, feed and posture detection. The movement form of the mechanism is simple and efficient, easy to feedback and control, and has good dynamic stability. At the same time, the structure is simple and compact, and is easy to manufacture and assemble; the present invention adopts a parallel structure, which makes the mechanism constraint stiffness high, the moving parts have a small mass, the force perception effect is good, and the reliability is high, which can effectively reduce the inertia of the end effector and improve the dynamic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of the present invention in a general posture;

[0018] Figure 2 This is a schematic structural diagram of the present invention;

[0019] Figure 3 This is a schematic diagram of the structure of the present invention in posture 2;

[0020] 1-second crankshaft, 2-left branch chain semicircular rope pulley, 3-first motor support frame, 4-first crankshaft, 5-first short shaft, 6-feed friction wheel support frame, 7-feed torque motor, 8-operating handle, 9-rotating motor support frame, 10-rotating torque motor, 11-feed friction large wheel, 12-second motor support frame, 13-right torque motor, 14-left torque motor, 15-first rotating shaft, 16-moving platform body, 17-first feed friction small wheel, 18-second feed friction small wheel, 19-sleeve, 20-rotating rope pulley, 21-feed motor support frame, 22-second short shaft, 23-second rotating shaft, 24-right branch chain semicircular rope pulley, 25-static platform, 26-support square tube, 27-third rotating shaft, 28-feed rope pulley, 29-square tube support frame, 30-fourth rotating shaft. DETAILED DESCRIPTION

[0021] like Figure 1-3 As shown, the present invention includes a second crankshaft 1, a left branch chain semicircular rope pulley 2, a first motor support frame 3, a first crankshaft 4, a first short shaft 5, a feed friction wheel support frame 6, a feed torque motor 7, an operating handle 8, a rotating motor support frame 9, a rotating torque motor 10, a feed friction large wheel 11, a second motor support frame 12, a right branch chain torque motor 13, a left branch chain torque motor 14, a first rotating shaft 15, a moving platform body 16, a first feed friction small wheel 17, a second feed friction small wheel 18, a sleeve 19, a rotating rope pulley 20, a feed motor support frame 21, a second short shaft 22, a second rotating shaft 23, a right branch chain semicircular rope pulley 24, a static platform 25, a supporting square tube 26, a third rotating shaft 27, a feed rope pulley 28, a square tube support frame 29, and a fourth rotating shaft 30.

[0022] The static platform 25 is fixedly installed, and the main parts of the mechanism are installed on the static platform 25. The first motor support frame 3 and the second motor support frame 12 are respectively installed on the static platform 25. The left branch chain torque motor 14 and the right branch chain torque motor 13 are respectively installed on the first motor support frame 3 and the second motor support frame 12. The first rotating shaft 15 and the second rotating shaft 23 are respectively connected to the first motor support frame 3 and the second motor support frame 12 through a rotating pair. The left branch chain semicircular rope pulley 2 and the right branch chain semicircular rope pulley 24 are respectively connected to the first rotating shaft 15 and the second rotating shaft 23 through a rope.

[0023] The shorter side of the first crankshaft 4 is fixedly connected to the left branch semicircular rope pulley 2, and the longer side is connected to the first short shaft 5 via a revolute pair. The shorter side of the second crankshaft 1 is fixedly connected to the right branch semicircular rope pulley 24, and the longer side is connected to the second short shaft 22 via a revolute pair. The axes of the left branch semicircular rope pulley 2, the right branch semicircular rope pulley 24, and the movable platform body 16 intersect at a point.

[0024] The first short shaft 5 is connected to the movable platform body 16b via a rotating pair, the second short shaft 22 is fixedly connected to the movable platform body 16b, and the axes of the first short shaft 5, the second short shaft 22 and the movable platform body 16 intersect at one point.

[0025] The feed friction wheel support frame 6 is fixedly connected to the movable platform body 16. The first feed friction wheel 17, the second feed friction wheel 18, and the feed friction wheel 11 are respectively connected to the feed friction wheel support frame 6 via a revolving pair. The axis connecting the first and second feed friction wheels 17, 18, and the centerline of the groove of the feed friction wheel 11 are coplanar with the axis of the supporting square tube 26. The grooves of the first, second, and feed friction wheels 17, 18, and 11 are fully aligned with the supporting square tube 26, and the friction force of the contact surface controls the longitudinal feed of the supporting square tube 26. The square tube support frame 29 is fixedly connected to the movable platform body 16 to limit the rotation of the supporting square tube 26.

[0026] The feed motor support frame 21 is fixedly connected to the moving platform body 16, and the feed torque motor 7 is fixedly connected to the feed motor support frame 21. The third rotating shaft 27 is connected to the feed motor support frame 21 via a revolute pair, and the third rotating shaft 27 is connected to the feed rope pulley 28 via a rope, mapping the longitudinal feed of the supporting square tube 26 to the rotation of the feed torque motor 7.

[0027] The rotating torque motor 10 is fixedly connected to the rotating motor support frame 9, the sleeve 19 is fixedly connected to the rotating motor support frame 9, and the supporting square tube 26 is fixedly connected to the sleeve 19. The fourth rotating shaft 30 is connected to the rotating motor support frame 9 via a revolute pair, the rotating rope pulley 20 is connected to the sleeve 19 via a revolute pair, and the fourth rotating shaft 30 is connected to the rotating rope pulley 20 via a rope, mapping the rotational freedom of the operating handle 8 to the rotation of the rotating torque motor 10. The working rotating shaft of the operating handle 8 is located inside the supporting square tube 26, and the axes of the two coincide.

[0028] The operating principle of the present invention is as follows: an operator manually pulls the operating handle 8, which contains a working shaft. On the one hand, the operating handle 8 rotates, driving the rotating sheave 20, which in turn drives the fourth rotating shaft 30, ultimately mapping the rotational degrees of freedom of the operating handle 8 to the rotation of the rotating torque motor 10. On the other hand, the longitudinal feed motion of the operating handle 8 drives the longitudinal feed motion of the supporting square tube 26, thereby driving the rotation of the large feed friction wheel 11, which in turn drives the rotation of the feed sheave 28, ultimately mapping the longitudinal feed degrees of freedom of the operating handle 8 to the rotation of the feed torque motor 7. Finally, the movement of the operating handle 8 drives the movement of the movable platform body 16, which in turn drives the rotation of the left and right semicircular chain pulleys 2 and 24, respectively, which are transmitted through the first rotating shaft 15 and the second rotating shaft 23, ultimately mapping the two-degree-of-freedom posture motion of the movable platform body 16 to the rotation of the left and right chain torque motors 14 and 13 fixed to the stationary platform 25. All four degrees of freedom of the operating handle 8 (containing the working shaft) can be reflected on the four torque motors. By reading the position of the motor encoder and combining it with the program, real-time force feedback and mechanism posture monitoring can be achieved to complete the work.

[0029] Compared with existing technologies, this invention achieves distal centering motion of the upper platform of the mechanism. Furthermore, it offers a large range of motion, thus broadening its application. Finally, its simple and compact structure facilitates manufacturing and assembly. Its simple motion form facilitates feedback and control, and offers excellent dynamic stability. Its parallel structure provides high constraint stiffness and reliability, effectively reducing the inertia of the end effector and improving dynamic performance.

[0030] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery, comprising a static platform, a left branch chain, a right branch chain, a dynamic platform, a supporting square tube, a feed torque motor, a rotation torque motor, and an operating handle, characterized by: The static platform is provided with a left branch chain and a right branch chain, the left branch chain includes a left branch chain crankshaft, a left branch chain torque motor and a first short shaft, the left branch chain torque motor is fixedly installed on the static platform, one side of the left branch chain crankshaft is rotatably connected to the static platform, the left branch chain torque motor is driven and connected to the left branch chain crankshaft through a gear and / or a pulley mechanism, the other side of the left branch chain crankshaft is rotatably connected to the first short shaft, and the axes of the two rotating shafts on both sides of the left branch chain crankshaft intersect at a point in space; the right side branch chain includes a right branch chain crankshaft, a right branch chain torque motor and a second short shaft, the right branch chain torque motor is fixedly installed on the static platform, and the right branch chain crankshaft is one side. The side is rotatably connected to the static platform, the right branch chain torque motor is driven and connected to the right branch chain crankshaft through a gear and / or a pulley mechanism, and the other side of the right branch chain crankshaft is rotatably connected to the short shaft b; the supporting square tube is slidably connected to the moving platform, and the feed torque motor is fixedly installed on the moving platform, and the feed torque motor is driven and connected to the supporting square tube through a wheel rope and / or a gear rack mechanism to achieve longitudinal movement and provide driving force, the rotation torque motor is fixedly installed on the supporting square tube, and the operating handle is rotatably connected to the supporting square tube, and the rotation torque motor is driven and connected to the operating handle through a pulley and / or gear mechanism to achieve rotation and provide driving torque.

2. The decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery according to claim 1, characterized in that: The short shaft a is rotatably connected to the moving platform, and the rotation axis passes through the intersection of the rotation shaft axes on both sides of the left branch crankshaft, and the short shaft b is fixedly connected to the moving platform.

3. The decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery according to claim 2, characterized in that: The two rotating shaft axes on both sides of the right branch chain crankshaft intersect at one point and coincide with the intersection of the axis of the left branch chain. The dynamic platform can realize two-degree-of-freedom rotation around the intersection point under the drive of the left branch chain torque motor and the right branch chain torque motor.

4. The decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery according to claim 1, characterized in that: The left-branch torque motor, the right-branch torque motor, the feed torque motor and the rotation torque motor are all provided with encoders for relative parameter detection, and the detection objects of the encoders include rotation angle, position and speed motion parameters.

5. The decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery according to claim 1, characterized in that: The right torque motor, left torque motor, feed torque motor and rotation torque motor are provided with a torque instruction module, which is used to feedback an operation feedback force of a specific direction and a specific size to the operator by sending a specific torque instruction.

6. The decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery according to claim 1, characterized in that: One side of the left branch chain crankshaft is fixedly connected to a left branch chain semicircular rope pulley, and the left branch chain semicircular rope pulley is rotatably connected to the static platform. The left branch chain torque motor is connected to the left branch chain crankshaft through the left branch chain semicircular rope pulley to realize wheel rope torque drive; one side of the right branch chain crankshaft is fixedly connected to a right branch chain semicircular rope pulley, and the right branch chain semicircular rope pulley is rotatably connected to the static platform. The right branch chain torque motor is connected to the right branch chain crankshaft through the right branch chain semicircular rope pulley to realize wheel rope torque drive.

7. The decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery according to claim 1, characterized in that: The movable platform includes a movable platform body and a square tube support frame. The movable platform body is fixedly installed with a feed friction wheel support frame. The feed friction wheel support frame is installed with a feed friction large wheel, a first feed friction small wheel and a second feed friction small wheel that are in contact with the supporting square tube. The feed friction large wheel is connected to the feed rope pulley, the square tube support frame and the feed friction wheel support frame, and the supporting square tube is slidably connected to the square tube support frame.

8. The decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery according to claim 7, characterized in that: The feed torque motor is connected to a feed motor support frame, the feed motor support frame is rotatably connected to a third rotating shaft, and the third rotating shaft is connected to the feed rope pulley.

9. The decoupled four-degree-of-freedom force feedback mechanism for laparoscopic surgery according to claim 1, characterized in that: The rotating torque motor is provided with a rotating motor support frame, the rotating motor support frame is provided with a sleeve, the sleeve is rotatably connected to a rotating sheave, the rotating motor support frame is fixedly connected to the supporting square tube through the sleeve, the rotating motor support frame is installed with a fourth rotating shaft through a rotating pair, and the fourth rotating shaft is connected to the rotating sheave rope.

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