Magnetic Soft Continuum Robots With Braided Reinforcement

Abstract

Flexible catheters are used in a wide variety of surgical interventions including neurological, pancreatic and cardiovascular. In many cases a lack of dexterity and miniaturization along with excessive stiffness results in large regions of the anatomy being deemed inaccessible. Soft continuum robots have the potential to mitigate these issues. Due to its enormous potential for miniaturization, magnetic actuation is of particular interest in this field. Currently, flexible magnetic catheters often rely on interactive forces to generate large deformations during navigation and for soft anatomical structures this could be considered potentially damaging. In this study we demonstrate the insertion of a high aspect ratio, 50 mm long by 2 mm diameter, soft magnetic catheter capable of navigating up to a 180 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> bend without the aid of forces of anatomical interaction. This magnetic catheter is reinforced with a lengthwise braided structure and its magnetization allows it to shape form along tortuous paths. We demonstrate our innovation in a planar silicone pancreas phantom. We also compare our approach with a mechanically equivalent tip driven magnetic catheter and with an identically magnetized, unreinforced catheter.