A ferromagnetic notched soft guidewire for enhanced flexibility

Ferromagnetic soft guidewires (FSGs) capable of remote active steering and navigation offer substantial potential for biomedical applications. However, in practical applications, such as tasks requiring navigation through large-angle bends in narrow spaces and carrying loads, the performance of FSG is limited. This paper presents a design framework for ferromagnetic notched soft guidewires (FNSGs) that significantly enhances steering performance while maintaining sufficient stiffness. Then, an modified segmented Cosserat rod model is proposed and validated through finite element analysis and experiments, providing an effective tool for the analysis of FNSGs. Moreover, analysis of the workspace and the bending stiffness is conducted on FNSG design with different notch geometric parameters, revealing that the notches have a significant impact on the deflection of FNSG along different directions. Finally, the superior performance of the FNSG in navigation, maneuvering through large-angle bends, and bearing heavy loads was demonstrated through an integrated magnetic field system.