Electromagnets Under the Table: an Unobtrusive Magnetic Navigation System for Microsurgery

TL;DR

This paper presents a novel magnetic navigation system with eight electromagnets beneath the operating table, enabling minimally invasive microsurgical procedures with maximal workspace accessibility and sufficient magnetic field strength for brain microsurgery.

Contribution

The design of an unobtrusive electromagnet array under the operating table that maximizes workspace and magnetic field uniformity for microsurgical applications is introduced.

Findings

Achieves magnetic fields up to 38 mT (x,y) and 47 mT (z) at 120 mm distance.

Validates forces on millimeter-scale magnetic tools experimentally.

Enables control of micro-robots in surgical environments.

Abstract

Miniature magnetic tools have the potential to enable minimally invasive surgical techniques to be applied to space-restricted surgical procedures in areas such as neurosurgery. However, typical magnetic navigation systems, which create the magnetic fields to drive such tools, either cannot generate large enough fields, or surround the patient in a way that obstructs surgeon access to the patient. This paper introduces the design of a magnetic navigation system with eight electromagnets arranged completely under the operating table, to endow the system with maximal workspace accessibility, which allows the patient to lie down on the top surface of the system without any constraints. The found optimal geometric layout of the electromagnets maximizes the field strength and uniformity over a reasonable neurosurgical operating volume. The system can generate non-uniform magnetic fields up to 38 mT along the x and y axes and 47 mT along the z axis at a working distance of 120 mm away from the actuation system workbench, deep enough to deploy magnetic microsurgical tools in the brain. The forces which can be exerted on millimeter-scale magnets used in prototype neurosurgical tools are validated experimentally. Due to its large workspace, this system could be used to control milli-robots in a variety of surgical applications.