Surgical manipulator

• US 8,491,603 B2
• Filed: 06/14/2007
• Issued: 07/23/2013
• Est. Priority Date: 06/14/2006
• Status: Active Grant

• Current Assignee: Macdonald Dettwiler and Associates Limited
• Original Assignee: Macdonald Dettwiler and Associates Limited
• Inventors: Yeung, Benny Hon Bun, Gregoris, Dennis, Bednarz, Bronislaw, Gray, Michael A.
• Primary Examiner(s): HAND, MELANIE JO
• Application Number:
  US11/812,094
• Publication Number:
  US 20070299427A1
• Time in Patent Office: 2,231 Days
• Field of Search: 606/130, 606/1, 700/264, 414 5- 7, 600/101, 600/102, 600/114, 600/121, 600/130, 901 14- 16, 901/19, 901/21, 901/23, 901/28, 901/29
• US Class Current: 606/130
• CPC Class Codes: A61B 2034/305 Details of wrist mechanisms at distal ends of robotic arms
• CPC Class Codes: A61B 2034/715 Cable tensioning mechanisms for removing slack
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/37 Master-slave robots A61B34/35 takes precedence
• CPC Class Codes: A61B 34/71 Manipulators operated by drive cable mechanisms
• CPC Class Codes: A61B 34/77 Manipulators with motion or force scaling
• CPC Class Codes: A61B 46/10 specially adapted for instruments, e.g. microscopes
• CPC Class Codes: A61B 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: B25J 9/047 the pivoting axis of the first arm being offset to the vertical axis
• CPC Class Codes: B25J 9/104 with cables, chains or ribbons

Abstract

The present invention provides a surgical manipulator including a manipulator arm, an end-effector held by the robotic arm, surgical tools held by the end-effector and manipulator joints, particularly right-angle drive devices for transmitting rotational motion in one axis to a perpendicular axis.

Claims

1. A surgical end-effector, comprising:

a) an assembly including an interface configured to be attached to a robotic arm, a tool-yaw motor, a tool-actuation motor;

b) a magnetic tool holder mounted to said assembly and being detachable therefrom, said magnetic tool holder being configured to automatically engage and release a surgical tool;

c) a tool-actuation mechanism mounted to said assembly and being detachable therefrom, said tool-actuation mechanism being configured to automatically engage and release a piston on the surgical tool, said tool-actuation mechanism being coupled to said tool-actuation motor; and

d) a tool-yaw drive mechanism mounted to said assembly and being detachable therefrom, said tool-yaw drive mechanism being coupled to said tool-yaw motor, wherein upon activation of said tool-yaw drive mechanism the surgical tool engaged by said magnetic tool holder rotates about said tool-yaw axis and wherein upon activation of said tool-actuation mechanism the piston of the engaged surgical tool is linearly retracted or linearly extended with respect to said end-effector thereby activating a tool portion of the surgical tool.

2. The surgical end-effector according to claim 1 wherein said interface includes a base block which interfaces to a wrist of a robotic arm, including a motor-support bracket on which the tool-actuation motor and the tool-yaw motor are mounted, and wherein said assembly includes a tool-tip force-moment sensor which is a single mechanical linkage between said motor-support bracket and said base block.

3. The surgical end-effector according to claim 1 wherein said tool-actuation motor is a linear actuator having an output shaft which moves up and down along a major axis of said tool-actuation motor and, at a distal end portion of said output shaft, an actuator bar is connected at a first end portion thereof, said actuator bar having a second end portion supported by a vertical guide rod and including an interface which couples to said tool-actuation mechanism, wherein said actuator bar transmits vertical motion of said output shaft to said tool-actuation mechanism which is mounted at said second end of the bar such that said vertical motion provides a tool-actuation axis of motion for said end-effector.

4. The surgical end-effector according to claim 3 including a tool-actuation force sensor mounted on said actuation bar between a point where said actuation bar is supported by said vertical guide rod and said interface with the tool-actuation mechanism.

5. The surgical end-effector according to claim 4 wherein said tool-actuation force sensor is a strain gauge, at which point on the bar on which said force sensor is mounted, any elastic vertical deflection due to actuation of the surgical tool can be measured.

6. The surgical end-effector according to claim 1 wherein said tool-yaw mechanism includes a frame, on which is mounted a pair of idler pulleys, a middle idler pulley and a drive pulley, including a toothed belt being routed on said idler pulleys, said middle idler pulley and said drive pulley, said toothed belt being configured to engage a toothed pulley on the surgical tool, on two opposite ends of a diameter of said toothed pulley, and wherein bi-directional rotation of the toothed belt driven by said drive pulley converts tangential forces to rotary motion of the surgical tool.

7. The surgical end-effector according to claim 6 wherein said frame has an open front-framed architecture and a toothed belt routing configuration on said idler pulleys and said middle idler pulley configured to allow the surgical tool to be ejected/replaced from said end-effector.

8. The surgical end-effector according to claim 6 wherein said frame includes sheet metal flexures supporting said outer idler pulleys so that said outer idler pulleys can be passively spread out enough to completely disengage the surgical tool thereby eliminating any frictional effects, and wherein when engaged with the surgical tool, the metal flexures allow a constant preload to said toothed belt during tool yawing but can also manually collapse, when no surgical tool is present, for facilitating toothed belt replacement.

9. The surgical end-effector according to claim 6 wherein said tool-yaw motor includes a drive shaft having a shape complementary to a shape of a bore on said drive pulley for insertion into said bore for enabling torque to be transmitted to said tool-yaw mechanism, while allowing easy de-coupling of said shaft from said drive pulley.

10. The surgical end-effector according to claim 6 wherein said tool-yaw motor includes a servo motor integrated with an anti-backlash spur gearhead and an incremental encoder.

11. The surgical end-effector according to claim 1 wherein said magnetic tool holder, said tool-actuation mechanism, and said tool-yaw mechanism are sterile subassemblies, with quick release and attachment features for quickly attaching and detaching them to and from said assembly.

12. The surgical end-effector according to claim 1 wherein, when in operation, said surgical end-effector is coupled to a robotic wrist, which is connected to a robotic lower arm, which is connected to a robotic fore arm which, is connected to a surgical manipulator base, and wherein said assembly, said tool-yaw mechanism and said tool-actuation mechanism, are encapsulated in a protective drape bag which covers from the base of the surgical manipulator all the way through the entire length of the robotic fore arm, the robotic lower arm and the robotic wrist and up to a front face of said assembly.

13. The surgical end-effector according to claim 1 wherein said magnetic tool holder includes a support body having an elongate channel having a size suitable to receive therein a cylindrical tool body of the surgical tool, and wherein the cylindrical tool body is made of a magnetic material, and wherein said support body includes at least one magnet embedded therein adjacent to said elongate channel for magnetically restraining the magnetic cylindrical tool body.

14. The surgical end-effector according to claim 13 wherein said support body is made of a material which allows the surgical tool to rotate with minimal friction within said support body when rotated by said tool-yaw mechanism.

15. The surgical end-effector according to claim 13 wherein the surgical tool includes flanges on the cylindrical tool body for locating and constraining the surgical tool axially within said channel in said support body due to a close axial fit with said support body.

16. The surgical end-effector according to claim 13 wherein said magnetic tool holder includes a tool release mechanism including a pair of tool-ejection wings pivotally mounted on said support body with a portion of each wing located in said channel behind said cylindrical tool body and configured such that once said tool-ejection wings compressed on outer surfaces thereof, tool-ejection wings pivot in a scissor action, to strip the cylindrical tool body away from said at least one magnet responsively ejecting the surgical tool from said magnetic tool holder.

17. The surgical end-effector according to claim 16 wherein said tool-actuation mechanism includes a pair of pivoting fingers pivotally mounted to a support member with matched end portions configured to engage and hold a portion of a piston on the surgical tool.

18. The surgical end-effector according to claim 1 wherein said end-effector includes a tool-tip force-moment sensor mounted to said end-effector and configured to sense tool tip force and moment at a tip of a surgical tool engaged by said end-effector, and wherein said end-effector includes a tool-actuation force sensor mounted thereon configured to measure actuation forces on a tip of the surgical tool.

19. The surgical end-effector according to claim 1 wherein said surgical tool includes a stationary body and a piston configured to slide within said stationary body.

20. The surgical tool according to claim 19 wherein said piston has a narrow neck feature compatible for grasping by said surgical end-effector.