Moving Beyond Compliance in Soft-Robotic Catheters Through Modularity for Precision Therapies

Abstract: Soft robotic instruments could navigate delicate, tortuous anatomy more safely than rigid tools, but clinical adoption is limited by insufficient tip functionalization and real-time feedback at the tissue interface. Few sensing and therapeutic modules are compact, robust, and adaptable enough to measure, and respond to, subtle physiological cues during intraluminal procedures. We present a 1.47 mm diameter modular soft robotic catheter that integrates sensing, actuation, and therapy while retaining the compliance needed for safe endoluminal navigation. Validated across multiple in vivo settings, we emphasize its utility in endoscopic retrograde cholangiopancreatography (ERCP), a highly technical procedure and a key access route to the pancreas, an organ that is fragile, difficult to instrument, and central to diseases such as pancreatic cancer. Our architecture supports up to four independently controlled functional units, allowing customizable combinations of anchoring, manipulation, sensing, and targeted drug delivery. In a live porcine model, we demonstrate semi-autonomous deployment into the pancreatic duct and 7.5 cm of endoscopic navigation within it, a region currently inaccessible with standard catheters. A closed-loop autonomous/shared-control system that combines a learned model, magnetic actuation, onboard shape sensing, and visual marker tracking further improves cannulation accuracy. Together, these results establish a scalable platform for multifunctional soft robotic catheters and a new paradigm for complex endoluminal interventions, with potential to reduce radiation exposure, shorten training, and accelerate clinical translation of soft robotic technologies.