Endoscopic Capsule Robots Using Reconfigurable Modular Assembly: A Pilot Study

Abstract

Ingestible capsule endoscopy provides a method of imaging the gastrointestinal (GI) tract with increased patient comfort compared to traditional tube-based endoscopy. However, many capsule endoscopic platforms lack locomotion and inherent size-restrictions prohibit the implementation of high-order functionality other than image acquisition. To overcome these limitations, we proposed a modular system of robots containing steerable locomotive elements with unique functionalities that are capable of assembling into a larger and more complex robot via mutual docking. The prototype capsules were approximately the size of D-cell batteries. The three sets of radio-controlled modular robotic capsules were designed to move using a combination of continuous-rotational servos and angular servos for steering and locomotion. A docking mechanism was achieved by permanent magnets (attached to the linear servo installed in the capsule) while a structural slit allowed for correct docking orientation. Additional center capsules were capable of rotational locomotion or image transfer via a housed camera and three docking ports for the capsules to dock. When fully assembled, a four-capsule assembly exhibited controlled locomotion and wireless video transmission. With potential integration with wireless power transmission, as demonstrated by the acoustic power transmission via focused ultrasound, the proposed reconfigurable robotic capsule platform may provide unique opportunities in administering minimally invasive theragnostic applications.