Medical Instrument Motion Control for DOF-Mismatched Robotic Input
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Solution Overview
Problem
Existing robotic systems for medical instruments face challenges in controlling the movement of end effectors due to mismatches between the degrees of freedom (DOFs) of the input device and the instrument, leading to inefficiencies and limitations in maneuverability during medical procedures.
Innovation Solution
The system employs a robotic arm with an input device that modifies the Jacobian matrix by discarding rows to align the DOFs of the input device with those of the end effector, allowing for precise control and maneuverability of medical instruments through techniques like telescopic extension and independent movement of instrument parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the input device has more degrees of freedom than the medical instrument, then the input device can provide more movement options, but the instrument cannot achieve all the commanded movements
Solution Approach 1:
The system extracts and removes the incompatible degrees of freedom from the control mapping. The Jacobian matrix modification process identifies and discards rows corresponding to instrument DOFs that cannot be achieved, effectively separating the controllable from the uncontrollable movement dimensions and preventing erroneous command transmission.
Solution Approach 2:
The system dynamically modifies the Jacobian matrix parameters based on the actual instrument capabilities. By adjusting the matrix structure to match the instrument's true degrees of freedom, the control system adapts its parameter set to ensure reliable command execution within the instrument's physical limitations.
2Measurement precision
If the Jacobian matrix is modified by discarding rows to match instrument DOFs, then control precision is improved, but information about unachievable movements is lost
Solution Approach 1:
The modified Jacobian matrix serves as an intermediary transformation that maps input device movements to achievable instrument movements. This intermediary structure preserves essential control information while filtering out unachievable movement components, maintaining the integrity of the control signal within the instrument's capabilities.
3Device complexity
If the robotic system uses a fixed Jacobian matrix, then the control algorithm is simpler, but it cannot adapt to instruments with varying degrees of freedom
Solution Approach 1:
The system transitions from a static Jacobian matrix to a dynamic one that adapts to the specific instrument configuration. The Jacobian matrix is modified in real-time based on the instrument's actual degrees of freedom, allowing the control algorithm to remain relatively simple while achieving high adaptability across different instrument types.
Data Source
AI summary
Systems and methods for constrained motion control of medical instruments are provided. In one aspect, a robotic system includes an instrument having an end effector, a robotic arm configured to control movement of the instrument and the end effector, and an input device configured to receive an input for controlling movement of the instrument and end effector. The instrument is capable of moving in a different number of degrees-of-freedom (DOFs) than the input device. The system is configured to determine a Jacobian matrix relating the input to the input device to robotic arm commands for achieving a motion of the end effector indicated by the input, modify the Jacobian matrix via discarding at least one row of the Jacobian matrix, and determine a robotic arm command for achieving the motion of the instrument indicated by the input based on the modified Jacobian matrix.