Trocar Pose Estimation Using Magnetic Sensing for Robotic Docking
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Solution Overview
Problem
Existing trocar docking techniques for surgical robotic arms face challenges such as interference from sterile barriers and reduced trocar lifespan due to electrically powered components, which can degrade over time and affect alignment accuracy.
Innovation Solution
Utilizing non-electrically powered permanent magnets in the trocar to generate magnetic fields detected by sensors on the robotic arm, coupled with a machine learning model to automatically align and dock the robotic arm, enabling precise alignment and mechanical coupling without line-of-sight requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrically powered components are used in the trocar to generate signals for guiding the robotic arm, then alignment accuracy can be achieved, but the trocar lifespan is reduced due to degradation from repeated use and sterilization procedures
Solution Approach 1:
The patent replaces electrically powered components with passive magnetic components. Specifically, permanent magnets are embedded in the trocar to generate magnetic fields for detection by sensors on the robotic arm, eliminating batteries, wires, and electronic circuits that would degrade during sterilization and repeated use. This substitution of electrical systems with magnetic field-based systems resolves the contradiction by maintaining measurement precision while dramatically extending trocar lifespan.
Solution Approach 2:
The patent makes the trocar a truly disposable, single-use instrument by removing all electronic components that would require maintenance or replacement. The passive magnetic components can withstand sterilization processes, allowing the trocar to be disposed of after one use without regret, thereby eliminating the lifespan issue entirely while maintaining alignment accuracy through the magnetic field detection system.
2Measurement precision
If visual imaging sensors are used to guide the robotic arm to the trocar, then alignment can be achieved, but sterile barriers block the sensors and interfere with docking procedures
Solution Approach 1:
The patent substitutes optical sensing systems with magnetic field sensing systems. Magnetic fields can penetrate sterile barriers, drapes, and other materials that block light, allowing the robotic arm to detect the trocar's position and orientation accurately without line-of-sight requirements. This substitution eliminates the harmful effect of sterile barriers blocking sensors while maintaining alignment precision.
3Ease of operation
If electrically powered components are used in the trocar for signal generation, then robotic arm guidance can be achieved, but the components degrade due to sterilization procedures and repeated use
Solution Approach 1:
The patent replaces electrical signal generation systems with passive magnetic field generation using permanent magnets. These magnetic components have no moving parts, no power requirements, and can withstand autoclaving and other sterilization processes without degradation. The robotic arm guidance functionality is maintained through magnetic field detection by sensors on the arm, while component reliability is dramatically improved by eliminating all electrical components from the disposable trocar.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances trocar docking robustness and versatility by maintaining the trocar's lifespan and accuracy, allowing for reliable alignment and coupling despite sterile barriers, and reducing reliance on electrically powered components.
Implementation Method 1
The use of magnets, for example, non-electrically powered magnets such as permanent magnets, in the trocar can provide magnetic fields for detection by a sensor system in a surgical robotic arm
Data Source
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AI summary
A surgical robotic system senses position or orientation of an object, which may be a trocar that has a magnetic field. Magnetic field sensors are coupled to a surgical robotic arm. A machine learning model coupled to the magnetic field sensors is trained to output three-dimensional position and/or three-dimensional orientation of the trocar or other object. Other aspects are also described.