Modeling Electromagnetic Navigation Systems

Abstract

Remote magnetic navigation is used for the manipulation of untethered micro and nanorobots, as well as tethered magnetic surgical tools for minimally invasive medicine. Mathematical modeling of the magnetic fields generated by magnetic navigation systems is a fundamental task in the control of such tools for biomedical applications. We describe and compare several existing and newly developed methods for representations of continuous magnetic fields using interpolation in the context of remote magnetic navigation. Clinical-scale electromagnetic navigation systems feature nonlinear magnetization and magnetization interactions between electromagnets, which renders accurate magnetic field modeling challenging. We first introduce a method that can adapt existing linear models to correct for nonlinear magnetization, with similar performance to the current state-of-the-art nonlinear model. Furthermore, we present a method based on convolutional neural networks that is able to improve on the state-of-the-art method by a factor of 5.4.

Using Magnetic Fields to Navigate and Simultaneously Localize Catheters in Endoluminal Environments

“…In the future, we plan to expand our tests to 3D models. We also plan to test our localization algorithm with other field models such as the one described in Charreyron et al [1]. The use of a linear model is particularly limited when trying to set specific magnetic gradients which lead the core of the electromagnets to saturate under higher currents [1].…”

“…We also plan to test our localization algorithm with other field models such as the one described in Charreyron et al [1]. The use of a linear model is particularly limited when trying to set specific magnetic gradients which lead the core of the electromagnets to saturate under higher currents [1]. A field model that compensates for the saturation behavior is thus expected to yield better results.…”

“…Minimally invasive surgery is a primary application area of RMN. Medical tools containing magnetic material can be navigated through the human body using external magnetic fields produced by a magnetic navigation system (MNS) [1]. Magnetic actuation allows the catheters to be generally softer and more flexible than their manual counterparts thus reducing the risk of tissue damage during procedures.…”

“…This work was supported by the Swiss National Science Foundation through grant numbers 200020B 185039 and 20B2-1 180861, by the ITC-InnoHK funding, and the ERC Advanced Grant 743217 Soft Micro Robotics (SOMBOT). 1 Multi-Scale Robotics Lab, ETH Zurich, Switzerland {fischece,qboehler,bnelson}@ethz.ch…”

A Simulation Framework for Magnetic Continuum Robots

“…An m-CR is composed of permanent magnets [4] or magnetic particles [5], [6] embedded along a flexible body in which deflection is induced by the torques produced on the magnets by externally generated magnetic fields. These magnetic fields can be generated with an electromagnetic navigation system (eMNS) [7]. This distal actuation allows an m-CR to generate tip forces while having a soft body, making it safe for interactions with human tissue.…”