DEMA: Robotic dual-electromagnet actuation system integrated with localization for a magnetic capsule endoscope

This paper presents a novel robotic dual electromagnetic actuation (DEMA) system capable of simultaneous actuation and localization of a magnetic capsule endoscope (MCE). The DEMA device, designed to generate a sufficiently controllable magnetic field, is attached to a robotic arm for the five degrees-of-freedom (DOF) motion of a magnetic capsule in the required workspace under considering the articulated robot payload. The electromagnets in the DEMA are independently controlled to achieve rapid magnetic actuation and high-frequency rotating magnetic fields. A transmitter attached to the DEMA to form a compact device and a receiver embedded inside the MCE are used to track the MCE in 5-DOF based on robot kinematics. We derived the dynamic equation motion of the MCE and presented the stability of the system. Finally, we demonstrated closed-loop control using the localization data, the diagnostic motion of the capsule, and biopsy functionality using the rotating magnetic field, through in-vitro and pig cadaver experiments. This study may advance wireless robot development while maximizing the benefit of conventional robotic and electromagnetic actuation.