Four-degree-of-freedom Magnetic Control of a Miniature Magnetic Robot for Intravascular Navigation Using Hybrid Magnet Arrays

We propose a magnetic control system for four-degree-of-freedom (4-DOF) actuation of an untethered permanent magnet, aimed at minimally invasive applications such as intravascular navigation. The system utilizes a hybrid magnet array combining permanent magnets and electromagnets, optimized to generate a magnetic field that diverges solely along the z-axis while converging in the x, y, 𝜃 and ϕ directions. This hybrid magnet array not only enables full 4-DOF control using feedback solely along the z-axis, thereby simplifying control, but also enhances energy efficiency by reducing the current required from the electromagnets through magnets. Furthermore, the open structure design provides a larger workspace compared to conventional systems. Simulation results validate the feasibility and effectiveness of the proposed approach, highlighting its potential for future application in magnetically actuated intravascular robotic systems.