Time-Scale Separation Analysis for Surgical Needle Control in Electromagnetic Robotic Systems

Abstract

In this work, we use the theory of time-scale separation to analyze motion of magnetic needles powered by electromagnetic coils for surgical tasks. In developing model-based controllers for such systems, it is often assumed that the magnetic needle orientation is aligned with the magnetic field direction. This assumption has enabled use of open-loop control techniques for orientation control of the magnetic agent. We provide a framework to show how this assumption might be highly inaccurate for certain system parameters. We show numerical simulations to depict this and validate results with experiments on a real magnetic control system. The results of this work can help ascertain whether the orientation alignment assumption is valid for a given set of parameters, paving the way to enable safe and accurate implementation of surgical tasks using magnetic needles in clinical settings.