Continuous Real-Time Inductive Tracking of Magnetic Microagents for Closed-Loop Control
Tim Grossrieder, Cameron Forbrigger, Myungjin Park, Michael Christiansen, Simone Schuerle
AI summary
Problem
Tracking magnetic microrobots currently relies on complex external imaging or secondary excitation hardware, which interrupts actuation and complicates clinical translation.
Approach
The method cancels the dominant driving magnetic field using compensation coils to isolate the microagent's induced voltage, extracting position and phase lag directly from the actuation signal.
Key results
- 3D localization of a 3 mm magnetic sphere via signal amplitude mapping
- Real-time phase lag estimation to quantify applied torque and predict step-out
- Closed-loop position control of a helical magnetic swimmer against fluid flow
- Continuous dynamic response tracking across multiple commercial actuation systems
Why it matters
Eliminates the need for secondary imaging hardware, paving the way for simpler, real-time controlled magnetic microrobotic interventions in medicine.
Abstract
Magnetic microrobots are on the rise, with many designs controlled via rotating magnetic fields (RMFs). Realizing their potential in medical treatments requires overcoming the difficulty of tracking them during navigation. We propose an inductive detection method leveraging RMFs simultaneously for sensing and control. By extracting inductive signals from the actuated agents, we achieve magnetic based tracking of position and phase lag without the need for secondary imaging modalities.