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 closedloop 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.