Kinetostatics of Magnetic Captained Elastica Driven by Revolutional and Rotational Magnet

Magnetic continuum robots (MCRs) hold considerable promise for medical applications, particularly in navigating the intricate and narrow lumens of the human body. However, accurately modeling their nonlinear large deformations, especially in nonuniform magnetic fields with bending angles exceeding 180°, poses a significant challenge. This research presents a theoretical framework for the magnetic captained elastica (MCE), which integrates magnetic dipole theory and the chained beam constraint model to effectively characterize the extreme deformations of permanent magnet-driven MCRs. The proposed kinetostatic model is rigorously validated through finite element simulations and experimental testing. Two permanent magnet actuation strategies, revolutional and rotational driving, are introduced to enhance precise deformation control, implemented via a specialized magnetic continuum robot navigation system. This system successfully demonstrates the MCE model's capability to transition between global large deformations and local small deformations, as evidenced by phantom experiments in gastric drug delivery and tracheal intubation. These findings underscore the model's accuracy and its significant potential for advancing clinical robotics.