Teleoperation Grip Ratcheting for Master-Slave Alignment
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Solution Overview
Problem
Current minimally invasive surgical systems require powered master tool manipulators for aligning master and slave surgical instrument tips, which can slow down surgical procedures and necessitate costly, powered components, while also introducing delays before teleoperation can begin.
Innovation Solution
A ratcheting system within the teleoperation servo control system continuously improves the alignment between the master grip and the slave surgical instrument tip in a common coordinate frame, allowing intuitive alignment without autonomous motion of either the master or slave, and enabling the use of unpowered master grips and lower-cost components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If powered master tool manipulators are used to align master and slave surgical instrument tips, then alignment accuracy is improved, but system cost and complexity increase
Solution Approach 1:
The patent replaces the mechanical powered alignment system with a computational software solution. The ratcheting algorithm automatically calculates and applies wrist joint angle adjustments to achieve master-slave alignment, eliminating the need for powered master tool manipulators while maintaining alignment accuracy.
Solution Approach 2:
The system dynamically adjusts wrist joint angles as a parameter to achieve alignment. The ratcheting mechanism modifies the wrist configuration parameters automatically based on the calculated difference between master and slave instrument orientations, providing precise alignment without mechanical power systems.
2Measurement precision
If powered master tool manipulators are used for alignment, then alignment precision is improved, but surgical procedure time increases
Solution Approach 1:
The ratcheting alignment mechanism performs preliminary automatic adjustments of the master wrist joints before the surgeon begins the surgical procedure. This preliminary action ensures alignment is achieved quickly and accurately, eliminating delays during the actual surgery.
Solution Approach 2:
The system performs self-alignment through the ratcheting mechanism, which automatically detects misalignment and applies corrective wrist joint adjustments without requiring manual intervention or powered actuators. The alignment process serves itself through automated computational control.
3Ease of operation
If powered components are used in the master tool manipulator, then alignment capability is improved, but system cost increases
Solution Approach 1:
The patent extracts the alignment capability from the mechanical powered system and relocates it to the software control system. By taking out the alignment function from the physical master manipulator and implementing it through computational algorithms, the system eliminates expensive powered components while preserving alignment capability.
Solution Approach 2:
The system creates a virtual model of the alignment process through software simulation and calculation. The ratcheting mechanism uses computational copying of the desired alignment state to determine the necessary wrist joint adjustments, replacing physical powered components with a virtual control model.
Data Source
AI summary
A teleoperated system includes a robotic arm configured to support an instrument, a grip configured to be manipulated by an operator to command motion of the instrument, and a control system communicatively coupled to the robotic arm and the grip. To align the grip with the instrument by the grip, the control system is configured to determine grip rotation values describing an orientation of the grip, determine instrument rotation values describing an orientation of the instrument, determine an orientation error between the orientation of the grip and the orientation of the instrument based on the grip rotation values and the instrument rotation values, produce a motion command by selectively imposing, based on the orientation error, an artificial joint limit on a commanded movement of the instrument, and command the robotic arm to move in accordance with the motion command.