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

Abstract

Remote magnetic navigation offers an ideal platform for automated catheter navigation. Magnetically guided catheters show great dexterity and can reach locations that are otherwise challenging to access. By automating aspects of catheterization procedures, we can simplify and expedite the procedure to allow surgeons to focus on other critical tasks during the surgery. In this article, we describe an automation strategy that is based on the center line of extracted and registered vascular geometries. Position feedback is accomplished with a Hall-effect sensor embedded near the distal end of the catheter. Sensor measurements are compared to the magnetic field predicted by a linear model of the electromagnetic navigation system. By defining specific magnetic field gradients and applying the known vascular geometry, the magnetic fields can be utilized for the simultaneous navigation and localization of the catheter. This eliminates the need for other external, dedicated mapping systems, and the use of fluoroscopy imaging is minimized. The concept is tested in 2d vascular models and the accuracy of the localization is assessed with overhead camera tracking.

Gradiometer-Based Magnetic Localization for Medical Tools

“…Parameters calculated with this model are expressed in the world frame {w}, denoted with the left subscript " w ", in which the model is calibrated. The linear model has been used in earlier studies [11], [15].…”

“…In our previous work, we demonstrated the possibility of using a single Hall sensor embedded in the distal tip Manuscript received June 22, 2022, revised August 24, 2022; Corresponding author: C. Fischer (email: fischece@ethz.ch). of a magnetic catheter to localize its position in a known constrained environment and use this position feedback to automate the catheter navigation [11]. However, the information of a single Hall sensor is insufficient to determine the sensor pose completely without changing the magnetic field and incurring additional geometric constraints.…”

Six-Degree-of-Freedom Localization Under Multiple Permanent Magnets Actuation

“…It requires, however, on-board power and heterogeneous localization magnetic fields, with 6-DOF localization having been shown for systems with a single external permanent magnet (EPM). Internal sensing methods have been shown for endoscopic capsules, as well as magnetically guided catheters [2], [16], [18], [19].…”

Magnetic Ball Chain Robots for Endoluminal Interventions

“…While substantial research effort has been invested in how to generate the external magnetic field, e.g., with combinations of electromagnetic coils [4], [5], [6], [7] or robot-mounted permanent magnets [8], [9], [10], [11], the systematic design of the steerable tip is a topic of current and growing interest [12], [13]. The earliest magnetic steerable tip designs were comprised of a single permanent magnet Fig.…”