SYSTEM FOR CONTROLLING ARTICULATION FORCES

• US 20190000577A1
• Filed: 06/29/2017
• Published: 01/03/2019
• Est. Priority Date: 06/29/2017
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Ethicon, LLC (Johnson & Johnson)
• Inventors: Shelton, IV, Frederick E., Harris, Jason L., Yates, David C.
• Granted Patent: US 10,258,418 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2017/00876 magnetic
• CPC Class Codes: A61B 2018/00797 measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2034/305 Details of wrist mechanisms at distal ends of robotic arms
• CPC Class Codes: A61B 2090/035 preventing further rotation
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2090/066 for measuring torque
• 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: B25J 9/1682 Dual arm manipulator; Coordination of several manipulators
• CPC Class Codes: B25J 9/1689 Teleoperation
• CPC Class Codes: G05B 19/4015 going to a reference at the beginning of machine cycle, e.g. for calibration
• CPC Class Codes: G05B 19/41815 characterised by the cooperation between machine tools, manipulators and conveyor or other workpiece supply system, workcell
• CPC Class Codes: G05B 2219/39135 For multiple manipulators operating at same time, avoid collision
• CPC Class Codes: G05B 2219/39212 Select between autonomous or teleoperation control
• CPC Class Codes: G05B 2219/39322 Force and position control
• CPC Class Codes: G05B 2219/40184 Compliant teleoperation, operator controls motion, system controls contact, force
• CPC Class Codes: G05B 2219/45117 Medical, radio surgery manipulator

Abstract

In some aspects, a control algorithm is provided for manipulating a pair of articulation arms configured to control an articulation angle of an end effector of a robotic surgical instrument. Other aspects of the present disclosure focus on the robotic arm system, including the pair of articulation arms coupled to the end effector and guided by independent motors controlled by a control circuit. Each of the articulation arms are designed to exert antagonistic forces competing against each other that are apportioned according to a ratio specified in the control algorithm. The ratio of the antagonistic forces may be used to determine the articulation angle of the head or end effector of the robotic surgical arm.

Claims

1. A system for a robotic surgical instrument, the system comprising:

a control circuit;

a first motor and a second motor, both communicatively coupled to the control circuit;

a first articulation arm communicatively coupled to the first motor;

a second articulation arm communicatively coupled to the second motor; and

an end effector coupled to the first articulation arm via a first hinge and the second articulation arm via a second hinge;

wherein;

the control circuit is configured to cause the first motor to apply a first force to the first articulation arm;

the control circuit is configured to cause the second motor to apply a second force to the second articulation arm, wherein the second force is antagonistic to the first force such that the first and second forces apply counteracting forces at the end effector;

the first and second forces cause the end effector to articulate via the first and second hinges; and

the end effector is configured to articulate to a prescribed angle based on a ratio of magnitudes between the first force and the second force.

3. The system of claim 1, further comprising an articulation pivot coupled to the end effector, wherein the end effector is further configured to articulate about the articulation pivot.

4. The system of claim 3, wherein the articulation pivot is positioned off of a center axis running longitudinally in between and equidistant from at least a portion of the first and second articulation arms.

5. The system of claim 3, further comprising a shaft encapsulating the first and second articulation arms.

6. The system of claim 5, further comprising a pivot link coupled to the articulation pivot and stably positioned within the shaft, wherein the pivot link is configured to stabilize the end effector while the end effector articulates about the articulation pivot.

7. The system of claim 6, wherein the pivot link and the articulation pivot are positioned off of a center axis running longitudinally in between and equidistant from at least a portion of the first and second articulation arms.

8. The system of claim 7, wherein the first force is greater than the second force when the end effector is articulated to a zero degree angle from a center position.

9. The system of claim 1, wherein the control circuit is configured to operate the first motor independent of the second motor.

10. The system of claim 1, wherein the first and second forces are pulling forces applied to the first and second articulation arms, respectively.

11. The system of claim 1, wherein the first and second forces are pushing forces applied to the first and second articulation arms, respectively.

2. (canceled)

12. A method of a robotic surgical instrument comprising a control circuit, a first motor, a second motor, a first articulation arm, a second articulation arm, and an end effector, the method comprising:

instructing, by the control circuit, the first motor to apply a first force to the first articulation arm;

instructing, by the control circuit, the second motor to apply a second force to the second articulation arm, wherein the second force is antagonistic to the first force such that the first and second forces apply counteracting forces at the end effector; and

causing the end effector to articulate to a prescribed angle via first and second hinges based on the first and second forces applied to the first and second articulation arms, respectively, and based on a ratio of magnitudes between the first force and the second force.

14. The method of claim 12, wherein the robotic surgical instrument further comprises an articulation pivot coupled to the end effector, wherein the end effector further articulates about the articulation pivot.

15. The method of claim 14, wherein the articulation pivot is positioned off of a center axis running longitudinally in between and equidistant from at least a portion of the first and second articulation arms.

16. The method of claim 14, wherein the robotic surgical instrument further comprises a shaft encapsulating the first and second articulation arms.

17. The method of claim 15, wherein the first force is greater than the second force when the end effector is articulated to a zero degree angle from a center position.

18. The method of claim 12, wherein applying the first force from the first motor is independent of applying the second force from the second motor.

19. The method of claim 12, wherein the first and second forces are pulling forces applied to the first and second articulation arms, respectively.

20. The method of claim 12, wherein the first and second forces are pushing forces applied to the first and second articulation arms, respectively.

13. (canceled)