A Magnetically-Actuated Flexible Capsule Robot for Untethered Cardiovascular Interventions

Robotic medical systems have been developed over the last few decades to reduce invasiveness and increase possibilities of minimally invasive surgery (MIS). This paper investigates a new, wireless, magnetically-actuated capsule robot as an untethered tool for cardiovascular surgery. The compliant magnetic capsule robot (CMCR) is designed to navigate larger blood vessels such as the abdominal aorta. Circular flexures provide the CMCR with radial adaptability, and the radial stiffness is analyzed using beam theory to calculate the actuation torque. Axial flexibility is also endowed onto the CMCR using a segmented structure and soft material core. Magnets are embedded on the CMCR to allow wireless actuation. Experiments are performed on prototypes of the CMCR to demonstrate its function as a proof-of-concept. Controlled actuation and adaptability of the CMCR are demonstrated in straight and curved tubes of varying diameters. Actuation of the CMCR in fluid flow and an approach for MIS insertion are also demonstrated to validate its potential for clinical application.