PULLEY ARRANGEMENT FOR ARTICULATING A SURGICAL INSTRUMENT

• US 20170172553A1
• Filed: 12/09/2016
• Published: 06/22/2017
• Est. Priority Date: 12/10/2015
• Status: Active Grant

• Current Assignee: CMR Surgical Ltd.
• Original Assignee: Cambridge Medical Robotics Limited
• Inventors: Chaplin, Ben Robert, Marshall, Keith, Hares, Luke David Ronald
• Granted Patent: US 10,499,891 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 17/00234 for minimally invasive surgery A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 17/2909 Handles
• CPC Class Codes: A61B 2017/00314 Separate linked members
• CPC Class Codes: A61B 2017/00323 Cables or rods
• CPC Class Codes: A61B 2017/00327 with actuating members moving in opposite directions
• CPC Class Codes: A61B 2017/2903 transferring rotary motion
• CPC Class Codes: A61B 2017/2908 Multiple segments connected by articulations
• CPC Class Codes: A61B 2017/292 connection of actuating rod to handle, e.g. ball end in recess
• CPC Class Codes: A61B 2017/2927 the angular position of the head being adjustable with respect to the shaft
• CPC Class Codes: A61B 2017/2929 with a head rotatable about the longitudinal axis of the shaft
• CPC Class Codes: A61B 2017/2932 Transmission of forces to jaw members
• CPC Class Codes: A61B 2017/2938 Independently actuatable jaw members, e.g. two actuating rods
• CPC Class Codes: A61B 2017/2944 Translation of jaw members
• CPC Class Codes: A61B 2017/2947 Pivots
• CPC Class Codes: A61B 2034/302 specifically adapted for manipulations within body cavities, e.g. within abdominal or thoracic cavities
• 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 34/71 Manipulators operated by drive cable mechanisms
• CPC Class Codes: B25J 9/1045 comprising tensioning means

Abstract

A robotic surgical instrument comprising a shaft and end effector element connected by an articulation. The articulation comprises a first joint driveable by a first pair of driving elements. The first joint permits the end effector element to rotate about a first axis transverse to a longitudinal axis of the shaft, the rotation of the end effector element about the first axis bounded by an extreme rotation angle relative to the longitudinal axis. A second joint is driveable by a second pair of driving elements. A pulley arrangement constrains the second pair of driving elements, and comprises a first set of pulleys rotatable about the first axis, and a second set of pulleys located relative to the first set of pulleys such that at the extreme rotation angle the second pair of driving elements is retained in contact with both the first and second sets of pulleys.

Claims

1. A robotic surgical instrument comprising:

a shaft;

an end effector element;

an articulation connecting the end effector element to the shaft, the articulation comprising;

a first joint driveable by a first pair of driving elements, the first joint permitting the end effector element to rotate about a first axis transverse to a longitudinal axis of the shaft, the rotation of the end effector element about the first axis bounded by an extreme rotation angle relative to the longitudinal axis, and

a second joint driveable by a second pair of driving elements; and

a pulley arrangement around which the second pair of driving elements is constrained to move, the pulley arrangement comprising;

a first set of pulleys rotatable about the first axis, and

a second set of pulleys located relative to the first set of pulleys such that at the extreme rotation angle the second pair of driving elements is retained in contact with both the first and second sets of pulleys.

2. A robotic surgical instrument as claimed in claim 1, wherein the second set of pulleys is located such that the second pair of driving elements is retained in contact with both the first and second sets of pulleys at any rotation angle of the end effector element relative to the longitudinal axis.

3. A robotic surgical instrument as claimed in claim 1, wherein the second joint permits the end effector element to rotate about a second axis transverse to the first axis.

4. A robotic surgical instrument as claimed in claim 1, wherein each pulley of the second set of pulleys is rotatable about an axis parallel to the first axis.

5. A robotic surgical instrument as claimed in claim 4, wherein each pulley of the second set of pulleys is rotatable about an axis offset from the first axis.

6. A robotic surgical instrument as claimed in claim 4, wherein the second set of pulleys comprises a first pulley rotatable about a third axis, and a second pulley rotatable about a fourth axis, the third axis being offset from the fourth axis.

7. A robotic surgical instrument as claimed in claim 1, wherein a distal end of the shaft is connected to the articulation, and a proximal end of the shaft is connected to a drive mechanism configured to drive the first and second pairs of driving elements, wherein the second set of pulleys is located between the first set of pulleys and the proximal end of the shaft.

8. A robotic surgical instrument as claimed in claim 7, wherein the second set of pulleys is located inside the shaft.

9. A robotic surgical instrument as claimed in claim 7, wherein the articulation comprises the second set of pulleys.

10. A robotic surgical instrument as claimed in claim 1, wherein:

the first set of pulleys comprises a first pulley and a second pulley located on opposing sides of the first joint; and

the second set of pulleys comprises a first pulley and a second pulley located on opposing sides of the first joint.

11. A robotic surgical instrument as claimed in claim 10, wherein the second pair of driving elements is constrained to move around opposing sides of the first and second pulley of the first set of pulleys.

12. A robotic surgical instrument as claimed in claim 10, wherein the second pair of driving elements is constrained to move around opposing sides of the first and second pulleys of the second set of pulleys.

13. A robotic surgical instrument as claimed in claim 1, further comprising a further end effector element, wherein the articulation further comprises a third joint driveable by a third pair of driving elements, the third pair of driving elements constrained to move around the pulley arrangement, the second set of pulleys being located relative to the first set of pulleys such that at the extreme rotation angle the third pair of driving elements is retained in contact with both the first and second sets of pulleys.

14. A robotic surgical instrument as claimed in claim 10, wherein the third joint permits the further end effector element to rotate about the second axis.

15. A robotic surgical instrument as claimed in claim 10, wherein each pulley of the first and second sets of pulleys comprises a pair of pulley elements, the pair of pulley elements comprising an inside pulley element and an outside pulley element, the inside pulley element located between the outside pulley element and the first joint, each pulley element comprising a groove configured to seat a driving element.

16. A robotic surgical instrument as claimed in claim 15, wherein:

the second pair of driving elements is constrained to move about the inside pulley element of the first pulley of the second set of pulleys and the outside pulley element of the second pulley of the second set of pulleys; and

the third pair of driving elements is constrained to move about the outside pulley element of the first pulley of the second set of pulleys and the inside pulley element of the second pulley of the second set of pulleys.

17. A robotic surgical instrument as claimed in claim 15, wherein:

the second pair of driving elements is constrained to move about the inside pulley element of the first pulley of the first set of pulleys and the outside pulley element of the second pulley of the first set of pulleys; and

the third pair of driving elements is constrained to move about the outside pulley element of the first pulley of the first set of pulleys and the inside pulley element of the second pulley of the first set of pulleys.

18. A robotic surgical instrument as claimed in claim 15, wherein for each pulley, one pulley element of the pair of pulley elements abuts the other pulley element of the pair of pulley elements.

19. A robotic surgical instrument as claimed in claim 13, wherein the second pair of driving elements and the third pair of driving elements have the same length for all rotation angles of the end effector element relative to the longitudinal axis.

20. A robotic surgical instrument as claimed in claim 13, wherein the first and second end effector elements are opposing first and second jaws of an end effector.