Low-Load endoluminal navigation with a magnetically actuated medical soft microrobot

Area of Science:

• Robotics
• Biomedical Engineering
• Control Systems

Background:

• Minimally invasive endoluminal interventions require precise navigation in confined spaces.
• Magnetic actuation is a key technology for steering soft microrobots within lumens.
• Limiting wall contact forces is crucial for patient safety during these procedures.

Purpose of the Study:

• To develop and evaluate a contact-aware control framework for magnetic soft microrobots.
• To improve steering accuracy and minimize wall loads during endoluminal navigation.
• To enhance the safety and efficacy of magnetic microrobotic interventions.

Main Methods:

• A dynamic model was developed, incorporating viscous drag, nonlinear friction, and viscoelastic wall contact.
• A closed-loop control architecture combined vision-based state estimation with model-based force inference.
• Magnet orientation was optimized to regulate the force vector and normal reaction force.

Main Results:

• Force-plus-angle control reduced root-mean-square tracking error by 56% and peak tracking error by 45%.
• Peak normal reaction force was attenuated by 60% compared to non-force-regulated control.
• Monte Carlo simulations confirmed the robustness and performance advantage of contact-aware control modes.

Conclusions:

• Force-aware magnet orientation is a critical control parameter for safe endoluminal navigation.
• The developed control methodology is transferable to future magnetic microrobotic platforms.
• Improved tracking performance does not necessitate increased peak contact forces.