JP2008212451A - Surgical manipulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manipulator having mechanisms for executing a parallel opening/closing operation similar to that of the distal ends of tweezers, executing a rotating operation at the distal end side of a bend shaft and preventing slack of wires. <P>SOLUTION: This manipulator 1 includes at least three degrees of freedom of the opening/closing of a pair of grip pieces 11a and 11b using a pantograph mechanism, the rotation around a first shaft positioned at the distal end side of a second shaft using a pulley 1 and a pulley 2, and the rotation around the second shaft. An actuation section moves a fourth shaft along a slit hole and, following thereto, moves a coupling 21 on a third shaft to prevent the slack of the wires. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

      The present invention relates to a surgical manipulator used for neurosurgery and the like.

            In neurosurgery, doctors need to work precisely to improve 5-year survival and prognosis. However, in neurosurgery, doctors need to perform extremely fine work within a very narrow work area. In addition, it is necessary to perform a long-time operation while being forced into a difficult posture. Therefore, in recent years, a surgical support robot in cooperation with diagnostic imaging equipment such as X-ray CT and MRI is desired.

            In neurosurgery, craniotomy is performed as a basic technique. Among surgical instruments used after craniotomy, tweezers are particularly frequently used and have a long use time. Therefore, the usefulness of the manipulator which has the function similar to the tweezers used during an operation is high.

For example, Non-Patent Documents 1 and 2 are cited as prior arts of this type of manipulator. As a product, “da Vinci surgical system” of Intuitive Surgical is known (see Non-Patent Document 3).
Tsuyoshi Ohura, 10 others, “Development of a laparoscopic surgical support bending long forceps manipulator”, Japan Society of Mechanical Engineers [No. 01-4] Robotics and Mechatronics Lecture '01 Proceedings, 2A1-D8, 2001 Koji Ikuta, 3 others, “Study on hyperfinger for remote abdominal surgery”, Japan Society of Mechanical Engineers [No. 00-2] Robotics and Mechatronics Lecture '00 Proceedings, 2P1-13-319, 2000 Gary S. Guthart and J. Kenneth Salisbury, Jr., “The Intuitive (TM) Telesurgery System: Overview and Application”, Proceedings of the 2000 IEEE International Conference on Robotics & Automation San Francisco, CA April 2000, pp. 618-621 , 2000

            First, in a conventional manipulator, when performing a rotating operation, rotational power is transmitted to the base of the manipulator shaft, and the entire manipulator rotates. Therefore, when the manipulator is rotated in a bent posture, the tip of the manipulator is displaced and is not suitable for use in an extremely narrow work area such as the deep brain. Therefore, a mechanism capable of rotating on the tip side with respect to the bending axis is useful.

            Secondly, in the conventional forceps and manipulator, the opening and closing operations are performed so that the tip portion draws an arcuate locus. However, since the opening width of the tweezers is small with respect to the length of the handle, the tweezers open and close in a substantially parallel state. Therefore, like the tweezers tip, a manipulator that opens and closes in parallel at the tip is superior in operability.

            Third, since the conventional manipulator uses a wire as a power transmission means, there are problems such as “elongation” and “sagging”.

            The present invention is directed to a manipulator that is driven by driving means, and more particularly to a manipulator used for neurosurgery or the like. Here, as the driving means, a driving device having an output shaft that reciprocates, for example, an actuator or the like can be used.

            The manipulator of the present invention has three degrees of freedom: opening and closing of a pair of gripping pieces, rotation of both gripping pieces around the first axis, and bending around the second axis. And the motive power from a drive means is converted into each motion of these degrees of freedom with a wire.

            One aspect of the manipulator of the present invention is composed of a pair of grip pieces and four link pieces (link piece a, link piece b, link piece c, link piece d) for opening and closing both grip pieces in parallel. A pantograph mechanism, a first shaft that rotatably couples both gripping pieces, a pulley 1 that rotates about the first shaft, a second shaft that is orthogonal to the first shaft, and the first and second shafts are fixed. A joint, a pulley 2 that rotates around a second axis installed on a side surface of the joint, and a pulley 3 are provided. The driving means is fixed to the driving section, and the driving section includes a third shaft rotated by the driving means, a coupling movable on the third axis, a bevel gear piece a fixed to the coupling, and a bulk. A bevel gear piece b meshing with the gear piece a, a pulley 4 fixed to the bevel gear piece b, and a fourth shaft movable in the third axial direction for rotating the bevel gear piece b and the pulley 4. .

            In this aspect, in order to open and close both gripping pieces in parallel, a pantograph mechanism is constituted by four link pieces (link piece a, link piece b, link piece c, link piece d). Each node is fixed with a pin so that it can rotate freely.

            In this aspect, one gripping piece is fixed to two end points so that one point can be rotated and the other point can be moved. Similarly, the other gripping piece is fixed to the other two end points, and one point is rotatable and the other point is movable.

            Also, the torsion spring is fixed to one point located in the center, both gripping pieces are opened by the restoring force of the torsion spring, the wire is fixed to the other point located in the center, and both gripping pieces are pulled by pulling the wire. close. Thereby, the parallel opening / closing operation | movement of both holding pieces is attained.

            In this aspect, by using the pulley 1 rotating around the first axis and the pulley 2 rotating around the second axis, it is possible to rotate around the first axis existing on the tip side from the second axis. Become. By causing the wires to cross once through both pulleys 1 and 2, it is possible to rotate around the first axis. Accordingly, even if the manipulator is rotated around the first axis in a bent posture, the manipulator can be rotated without displacement of the tip portion of the manipulator.

            The driving means is fixed to the rear surface of the driving portion, and the third shaft, the coupling, and one bevel gear piece are fixed to the driving means in order. In addition, a slit hole is provided in the upper surface of the drive unit and the bottom surface of the drive unit, and the fourth shaft is fixed to the slit hole so as to be movable in the third axis direction. The other bevel gear piece and the pulley 4 are fixed to the fourth shaft.

            In this aspect, when the fourth shaft is fixed to the forefront of the slit hole, the wire is wound up and fixed to the pulley 4, the fourth shaft to which the bevel gear piece and the pulley 4 are fixed is moved, and the wire is not loosened. To fix the fourth axis. Along with the movement of the fourth shaft, the bevel gear piece and the coupling are moved onto the third shaft and fixed to the third shaft. This makes it possible to eliminate the elongation / sagging of the wire.

          Exemplary embodiments of the present invention will be described in detail below with reference to the drawings.

          FIG. 1 shows a manipulation system including a manipulator according to an embodiment of the present invention.

          The system includes a manipulator 1 that is a manipulator body, a drive unit 2 that is a drive unit that drives the manipulator 1, and a control unit 3 that controls the drive unit 2. This manipulation system is used for neurosurgery and the like.

          The manipulator 1 includes an arm unit 10 attached to the driving unit 2 and a gripping unit 11 provided at the tip of the arm unit 10. The grip portion 11 is provided with a pair of grip pieces 11a and 11b that can be freely opened and closed. The grip portion 11 has one degree of freedom for opening and closing the grip pieces 11a and 11b in parallel. This one-degree-of-freedom motion is realized by transmitting the power of the drive unit 2 through a wire inserted into the arm unit 10.

          The drive unit 2 includes a DC motor 20, a coupling 21, bevel gear pieces 22a and 22b, and the like. The power (rotational motion) generated by the DC motor 20 is transmitted to the pulley 4 via the coupling 21 and the bevel gear pieces 22a and 22b to wind up the wire.

          The control unit 3 includes, for example, a computer and a master robot.

          When the operator (operator) operates the master robot, the movement information is input to the computer.

          The computer generates and outputs a control signal for the DC motor 20 based on the motion information. In accordance with this control signal, the DC motor 20 rotates, the rotation is transmitted to the pulley 4 through the coupling 21 and the bevel gear pieces 22a and 22b, and power in the pulling direction is applied to each wire wound up on the pulley 4. As a result, the gripping portion 11 of the manipulator 1 performs desired operations of gripping, rotation, and bending.

          Next, the configuration of the manipulator will be described in detail with reference to FIGS. 2 is a perspective view of the tip portion of the manipulator 1, FIG. 3 is a sectional view of the tip portion of the manipulator 1, FIG. 4 is a top view of the tip portion, FIG. 5 is a side view of the tip portion, and FIG.

As shown in these drawings, a pair of gripping pieces 11 a and 11 b are provided at the tip of the gripping portion 11 of the manipulator 1. The pantograph mechanism for opening and closing both gripping pieces in parallel is configured as follows. Rotatably pinned _{B 1} in the link pieces 12a and the link piece 12b and the side wall portion 13 of the node B _1, pin _{G 1} in each link piece 12c and the link piece 12d node _{G 1} and the node _{H 1} and pin _{H 1} in rotatably fixed, by fixing rotatable and slidable and so as to link piece 12c and the link piece 12d and the side wall portion 13 at the pin E ₁ in node E _1, constituting a pantograph mechanism.

The node A ₁ and gripping piece 11a, respectively pin A ₁ and pin D ₁ to node D ₁ is fixed, the node A ₁ is rotatably, node D ₁ is made to be slidable. Similarly, at the connection point C ₁ and the node F ₁ to secure the gripping piece 11b at pin C ₁ and pin F _1, node C ₁ is rotatably, node F ₁ is made to be slidable.

A torsion spring 14 is fixed to the pin B _1, and both the gripping pieces 11 are opened by the restoring force of the torsion spring 14, and the first wire 16 is fixed to the pin E ₁ , and the pin E is pulled by pulling the first wire 16. ₁ moves, and accordingly, the pin D ₁ and the pin F ₁ also move, and both gripping pieces 11 are closed. Thereby, the parallel opening / closing operation | movement of both the holding pieces 11 is attained.

          The rotating operation is performed by rotating the pulley 1 that rotates independently of the first shaft, the pulley 1 that rotates around the first shaft, the joint 15 that fixes the first shaft, and the joint 15 that rotates around the second shaft. By using it, it becomes possible to rotate around the first axis existing on the tip side from the second axis.

The second wire 17 is crossed once so as to pass through both pulleys 1 and 2, and the wire path is passed through point A ₂ , point B ₂ , point C ₂ , point D ₂ , point B ₂ , and point E ₂ in order. Thus, it becomes possible to rotate around the first axis. Accordingly, even if the manipulator is rotated around the first axis in a bent posture, the manipulator can be rotated without displacement of the tip portion of the manipulator.

The bending operation is performed by using the second axis, the joint 15 that rotates around the second axis, and the pulley 3 that rotates around the second axis fixed to the joint 15. The third wire 18 is routed around the pulley 3 in order of point A ₃ , point B ₃ , and point C _3, and bending is performed by pulling the third wire 18.

            The loosening of each wire is prevented as follows. The driving means is fixed to the rear surface of the driving portion, and the third shaft, the coupling 21 and the bevel gear piece 22a are fixed to the driving means in order. In addition, a slit hole 23 is provided on the top surface and bottom surface of the drive unit, and the fourth axis is fixed to the slit hole 23 so as to be movable in the third axis direction. The bevel gear piece 22b and the pulley 4 are fixed to the fourth shaft.

            In this embodiment, the fourth shaft is fixed at the forefront of the slit hole 23, and the screw 24 is left loose. The wire is wound around the pulley 4 and fixed, the fourth shaft to which the bevel gear piece 22b and the pulley 4 are fixed is moved along the slit hole 23, and the fourth shaft is fixed when the slack of the wire disappears. Along with the movement of the fourth axis, the bevel gear piece 22a and the coupling 21 are moved on the third axis, and the loosened screw 24 is tightened and fixed to the third axis. This makes it possible to eliminate the elongation / sagging of the wire.

            According to the configuration described above, it is possible to realize gripping by the parallel opening / closing operation mechanism in the gripping portion 11, rotation around the first axis, and bending motion around the second axis. Further, it is possible to prevent the slack of the wire in the driving unit 2.

The above embodiment is merely an example of the present invention. The scope of the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea.

It is a figure showing a manipulation system provided with a manipulator concerning one embodiment of the present invention. It is a perspective view of the tip part of a manipulator. It is sectional drawing of the front-end | tip part of a manipulator. It is a top view of the front-end | tip part of a manipulator. It is a side view of the front-end | tip part of a manipulator. It is a perspective view of the drive part of a manipulator. It is a figure which shows holding | grip operation | movement. It is a figure which shows rotation operation | movement. It is a figure which shows bending operation | movement. It is a figure which shows prevention of the slack of the wire of the drive part of a manipulator.

Explanation of symbols

1: Manipulator
2: Drive unit (drive means)
3: Control unit
10: Arm part
11: Grasping part 11a, 11b: Grasping piece
12: Link 12a, 12b, 12c, 12d: Link piece
13: Side wall
14: Torsion spring
15: Joint
16: First wire
17: Second wire
18: Third wire
20: DC motor
21: Coupling
22: Bevel gears 22a, 22b: Bevel gear pieces
23: slit hole
24: Screw
31: Pins 31A ₁ , 31B ₁ , 31C ₁ , 31D ₁ ,
31E ₁ , 31F ₁ , 31G ₁ , 31H ₁
32: Pulley 1
33: Pulley 2
34: Pulley 3
35: Pulley 4
36: 1st axis
37: Second axis
38: Third axis
39: Fourth axis

Claims (7)

          A surgical manipulator having a pair of grip pieces and performing a parallel opening and closing operation while the grip pieces maintain a relative angle.           2. The surgical manipulator according to claim 1, wherein the grasping piece opening / closing mechanism uses a pantograph mechanism composed of four links and a pin to realize a parallel opening / closing operation by moving the pin.           In the opening / closing mechanism, a first wire for driving is connected to the pin, and the gripping piece is closed by pulling the wire, and a torsion spring is arranged in the opening / closing mechanism to reduce the tension of the wire. The surgical manipulator according to claim 2, wherein the grasping piece is opened by a restoring force of the spring when the operation is performed.           In order from the manipulator tip side, at least 3 degrees of freedom of gripping by the opening / closing mechanism, rotational freedom around the long axis of the manipulator (first axis), and rotational freedom around the rotational axis perpendicular to the first axis (second axis) A surgical manipulator characterized by having a degree of freedom.           In the surgical manipulator, a pulley 1 that rotates about a first axis and rotates together with the opening / closing mechanism, a pulley 2 that is installed on a second axis and rotates freely, and a drive unit fixed to the pulley 1 via the pulley 2. 5. The surgical manipulator according to claim 1, further comprising: a second wire connected to the first wire, wherein the second wire is driven to operate a degree of freedom of rotation about the first axis. 6. In the drive section, the drive means, the rotation shaft (third axis) of the drive means, the coupling movable on the third axis, and the wire winding arranged perpendicular to the third axis by a pair of bevel gear pieces And a fourth shaft movable in the third axis direction. The fourth shaft, the pulley 4 and one of the bevel gear pieces move in the third axis direction, and on the third axis. A surgical manipulator characterized in that the tension of each wire can be adjusted by the movement of the coupling and the other bevel gear piece. A surgical manipulator having the features of claims 3, 5 and 6.