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Equilibrium Conformations of Concentric-tube Continuum Robots
D Caleb Rucker1, Robert J Webster1, Gregory S Chirikjian2
1Department of Mechanical Engineering, Vanderbilt University, 2301 Vanderbilt Place, PMB 351592, Nashville, TN 37235-1592, USA.
The International Journal of Robotics Research
|August 16, 2014
Summary
This study introduces a new model for active cannula robots, improving dexterity in minimally invasive surgery. The enhanced model accurately predicts robot behavior by including tube bending and torsion, reducing prediction errors significantly.
Area of Science:
- Robotics
- Surgical Technology
- Mechanical Engineering
Background:
- Active cannulas, composed of concentric elastic tubes, offer dexterity in confined surgical spaces.
- Existing models simplify tube precurvature and neglect torsion, limiting accuracy.
Purpose of the Study:
- To develop a novel, coordinate-free energy formulation for active cannulas.
- To incorporate general tube preshaping, bending, and torsion into a unified model.
- To enhance the predictive accuracy of active cannula behavior.
Main Methods:
- Developed a new energy formulation accounting for arbitrary tube preshaping.
- Explicitly included bending and torsion effects throughout the device.
- Validated the model against physical prototypes and compared it to prior models.
Main Results:
- The new formulation encompasses previous models as special cases.
- Torsional flexibility implications were explored for a two-tube system.
- Model prediction error was reduced by 82% (vs. bending-only) and 17% (vs. transmissional torsion).
Conclusions:
- The developed framework provides a more accurate representation of active cannula behavior.
- Accounting for torsion significantly improves model fidelity.
- This enhanced modeling capability is crucial for advancing robotic minimally invasive surgery.
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