An approach to capsular endoscopy with active motion

This paper describes a novel approach to capsular endoscopy that takes advantage of active legged locomotion in the gastrointestinal tract. The basic and essential functions that such a microdevice must possess are listed and discussed in details, as well as the specific features required in the different districts of the digestive path. Active legged locomotion was selected to achieve the adequate degree of flexibility and accuracy during the capsule journey. In addition, on-board locomotion mechanisms would allow to avoid bulky external driving systems that are typical of externally actuated devices. Two different prototypes, having 4 and 8 legs respectively, are presented, evaluated and tested. In particular, the 8-leg solution achieved a speed of 6 cm/min during in vitro tests. Moreover, it demonstrated capabilities of backward locomotion, vertical locomotion and locomotion around acute bends.