Magnetic Needle Steering in Soft Phantom Tissue.

Needle steering is a technology for guiding needles around sensitive internal obstacles in minimally invasive surgery. Traditional techniques apply rotation at the base of a needle with an asymmetric tip, enabling steering through the redirection of radial forces. Magnetic steering of catheters and continuum manipulators is another technology that allows steering of a shaft in the body. Both of these techniques rely on mechanical or manual shaft advancement methods. Needle steering has not achieved widespread clinical use due to several limitations: 1- buckling and compression effects in the shaft and needle rotation cause excessive tissue damage; 2- torsion effects on the shaft and needle deflection at tissue boundaries lead to difficulty in control; and 3- restricted radius of curvature results in limited workspace. Magnetically steered catheters and continuum manipulators also suffer from limited curvature and the possibility of buckling. This paper proposes a novel needle steering method empowered by electromagnetic actuation that overcomes all of the aforementioned limitations, making it a promising option for further study toward healthcare applications.