Localization accuracy of multiple magnets in a myokinetic control interface

Area of Science:

• Biomedical Engineering
• Robotics and Control Systems
• Magnetic Field Applications

Background:

• Magnetic localizers are crucial for intra-body applications due to their line-of-sight independence.
• Existing research has focused on specific aspects, lacking comprehensive design rules for multi-magnet localization.

Purpose of the Study:

• To systematically analyze factors influencing magnetic localizer accuracy, including magnetization, sensor count, and geometry.
• To establish general design principles for precise localization of multiple magnetic objectives in biomedical settings.

Main Methods:

• Conducted simulations to evaluate the impact of remanent magnetization, sensor number, and geometric configurations (L_inter-MM, L_MM-sensor).
• Validated simulation results with a physical system to ensure reliability.
• Identified a key geometric angle (θ = tan⁻¹(L_inter-MM / L_MM-sensor)) as a primary determinant of accuracy.

Main Results:

• Localization accuracy is predominantly governed by the system's geometric angle, θ.
• Achieved sub-millimeter accuracy (approx. 1 mm) and angular precision (approx. 9°) with nine magnets when θ ≥ 31°.
• This geometric rule remained consistent even when the number of magnets was doubled.

Conclusions:

• Established a general design rule for multi-magnet localization based on the geometric angle θ.
• The findings provide foundational principles for enhancing accuracy in various biomedical applications.
• Applicable to human-machine interfaces, capsule endoscopy, ventriculostomy interventions, and endovascular catheter navigation.