Surgical Robot Joint Force Estimation Without Direct Haptic Sensing
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Solution Overview
Problem
Existing surgical robots lack the ability to accurately determine and control the forces applied by their joints, especially when operating within a body cavity, which can lead to inefficiencies and potential harm to the patient.
Innovation Solution
A method and system for determining the output force applied by a cable-driven surgical robot's joint using a lumped-parameter model, involving kinematic parameters measured or estimated via sensors or dynamical simulation, and adjusting motor forces in real time to ensure precise control, with feedback provided through audiovisual representations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If force measurement sensors are added to the surgical robot, then force control precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces direct mechanical force measurement sensors with a computational model that calculates output joint forces based on motor forces and system dynamics. This substitution eliminates the need for additional force sensors while maintaining accurate force determination through mathematical modeling and control algorithms.
Solution Approach 2:
The system uses its existing sensors (motors, position sensors) to self-determine output forces through dynamic modeling. Rather than adding external measurement devices, the robot leverages its own operational data and mathematical models to compute forces, making the system self-sufficient for force measurement.
2Reliability
If real-time force adjustment is implemented, then surgical safety is improved, but computational requirements and processing time increase
Solution Approach 1:
The patent pre-computes system dynamic models and parameters during system setup and calibration phases. These pre-computed models are then used during real-time surgery to quickly determine forces without requiring complex real-time calculations, reducing computational burden while maintaining safety.
Solution Approach 2:
The system implements closed-loop feedback control where computed output forces are continuously monitored and used to adjust motor forces in real-time. This feedback mechanism ensures surgical safety by maintaining force within desired boundaries while using efficient computational algorithms to minimize processing requirements.
Data Source
AI summary
Described herein are methods and systems for determining force in a robotic surgical system. In some embodiments, a force applied by a robotic component (e.g. a robotic arm, a segment of a robotic arm, or a joint of a robotic arm) is determined. Also described herein are methods and systems for providing visual (e.g., direction and magnitude) feedback to a user without the need for direct haptic feedback. Such visual feedback may be presented to the user in conjunction with haptic feedback.