Master-Slave Orientation Mapping for Misaligned Surgical Instrument Tips
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surgical systems require precise alignment between the master tool grip and the slave surgical instrument tip, leading to delays and frustration due to repeated alignment processes, especially when there are swooping orientation misalignments, which result in unexpected motion of the slave surgical instrument tip during teleoperation.
Innovation Solution
The system relaxes the alignment criteria, allowing for a larger acceptable orientation misalignment between the master tool grip and the slave surgical instrument tip, using a controller that generates a desired orientation for the slave tip based on the master tool grip's orientation, ensuring intuitive motion following without unexpected rotations, by employing a relative rotation matrix and compensating for misalignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the system requires precise alignment between master tool grip and slave surgical instrument tip, then the motion accuracy and intuitive control are improved, but the alignment process time and user frustration increase due to repeated iterations
Solution Approach 1:
The system changes the parameter of acceptable orientation misalignment from a strict small angle to a larger swooping angle. The controller allows following mode to be entered even when orientation misalignment exceeds traditional thresholds, and compensates by generating desired slave orientations that account for the larger misalignment angle, thus reducing alignment iteration time while maintaining motion accuracy
Solution Approach 2:
The system replaces the mechanical alignment process (physically adjusting master tool to match slave instrument orientation) with a computational approach. The controller calculates and applies orientation compensation through rotation matrices, substituting mechanical adjustment with mathematical transformation to achieve accurate slave motion despite orientation misalignment
2Productivity
If the system allows larger orientation misalignment, then the alignment process is faster and less frustrating, but the slave surgical instrument tip may exhibit unexpected motion during teleoperation
Solution Approach 1:
The system uses feedback by continuously monitoring the actual orientation misalignment between master tool and slave instrument, comparing it against the desired relationship, and adjusting the slave orientation commands accordingly. The controller generates desired slave orientations based on the measured misalignment, ensuring predictable slave motion even with large initial orientation differences
Solution Approach 2:
The controller acts as an intermediary that mediates between the master tool input and slave instrument execution. It introduces a computational layer that calculates orientation compensation and transforms master tool motions into appropriate slave instrument commands, ensuring predictable and intuitive slave motion despite orientation misalignment
3Measurement precision
If the system uses motors in gimbal assembly to actively align orientations, then the orientation alignment accuracy is improved, but the device complexity and potential for displacement/orientation errors increase when surgeon grasps firmly
Solution Approach 1:
The system extracts the active motorized alignment mechanism from the master tool and relocates the alignment function to the controller software. Instead of using motors in the gimbal assembly to physically realign the master tool, the system calculates orientation compensation algorithms in the controller, eliminating complex mechanical alignment components while maintaining alignment accuracy
Data Source
AI summary
A system includes a master manipulator and a controller. The controller determines, before the system enters a following mode, a relative orientation between an orientations of an axis of the master manipulator in an eye frame and a corresponding axis of a slave instrument tip in a camera frame. After the system enters the following mode, the controller determines whether an orientation misalignment between the orientations of the axis of the master manipulator and the corresponding axis of the slave instrument tip is less than or equal to a maximum permitted orientation error. When the orientation misalignment is less than or equal to the maximum permitted orientation error, the controller receives a command indicating a desired orientation of the slave instrument tip from the master manipulator and commands the system to orient the slave instrument tip based on the desired orientation of the slave instrument tip and the relative orientation.