Sensor-Integrated Surgical Arm Control for Teleoperation and Manual Use
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Solution Overview
Problem
Existing surgical robotic systems face challenges in efficiently maneuvering medical instruments within the body without causing collisions and maintaining ergonomic positions for surgeons, particularly in minimally invasive procedures like laparoscopy and endoscopy.
Innovation Solution
The system incorporates a robotic arm with redundant degrees of freedom and a sensor system that allows for movement within a nullspace, enabling precise instrument positioning without moving the medical instrument, and includes a virtual rail mechanism for enhanced maneuverability and ergonomic control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the robotic arm uses redundant degrees of freedom to enable movement within nullspace, then the positioning precision of the medical instrument is improved, but the device complexity increases
Solution Approach 1:
The robotic arm incorporates redundant degrees of freedom by adding an additional joint that moves along a support rail, creating a new dimensional space (nullspace) for movement. This allows the system to adjust arm configuration without affecting instrument position, resolving the contradiction by separating positioning control from configuration adjustment.
Solution Approach 2:
The control system is segmented into independent components: one set of joints controls medical instrument position while another joint (with redundant degree of freedom) controls arm configuration along the support rail. This segmentation allows independent optimization of positioning precision and ergonomic adjustment without mutual interference.
2Ease of operation
If the robotic arm allows manual manipulation for ergonomic positioning, then the ease of operation is improved, but the stability of tele-operation control deteriorates
Solution Approach 1:
The robotic arm implements dynamic control mode switching between tele-operation and manual manipulation modes. During tele-operation, the system maintains stable automated control, while during manual manipulation, the redundant degree of freedom allows ergonomic adjustments. The system dynamically transitions between these states based on operational needs, resolving the contradiction between stability and ease of operation.
Solution Approach 2:
The support rail acts as an intermediary mechanism that decouples manual manipulation from the medical instrument position. When the surgeon manually adjusts the arm along the rail, the nullspace control ensures this movement does not displace the instrument, allowing ergonomic repositioning without compromising tele-operation stability.
3Adaptability or versatility
If the robotic arm moves linkages to adjust position, then the adaptability of positioning is improved, but the risk of collisions with adjacent structures increases
Solution Approach 1:
The redundant degree of freedom along the support rail provides an additional dimensional space for collision avoidance. When the robotic arm approaches adjacent structures, the system can adjust the arm configuration along the rail without moving the medical instrument, enabling the arm to navigate around obstacles while maintaining positioning adaptability.
Solution Approach 2:
The system uses a virtual model of the robotic arm to simulate and plan movements before execution. By copying the physical arm's configuration in a virtual environment, the system can predict potential collisions and adjust the path along the support rail to avoid adjacent structures, reducing collision risk while maintaining positioning flexibility.
4Reliability
If the system increases resistance to joint movement near adjacent structures, then the safety is improved, but the ease of operation deteriorates
Solution Approach 1:
The system applies differential resistance control to different joints based on their proximity to adjacent structures. Joints near obstacles experience increased resistance through impedance control, while joints in safe zones maintain normal operability. This localized quality adjustment ensures safety near critical structures without compromising overall ease of operation.
Solution Approach 2:
The system continuously monitors the position of the robotic arm relative to adjacent structures and dynamically adjusts joint resistance in real-time. When sensors detect proximity to obstacles, feedback signals increase resistance to prevent collision, while maintaining ease of operation when the arm is in safe positions. This feedback-based adaptive resistance resolves the contradiction between safety and operability.
Data Source
AI summary
Certain aspects relate to admittance control modes for a robotic surgery system. The admittance control modes can be based on detecting and/or measuring forces (rotational and/or nonrotational) on a robotic arm and moving the robotic arm in response to such interactions. The forces can include direct manual interaction with the robotic arm by a clinician. The movement of the robotic arm can be within a nullspace that maintains the positions of a medical instrument.