An internally-actuated mechanism for endoscopic capsules to reduce capsule retention: proof of concept

Endoscopic capsules are the only medical diagnosis devices that can examine the small intestine entirely. However, capsule retention is a critical side-effect of endoscopic capsules, which has remained unsolved. We aimed to reduce capsule retention probability by controlling the capsule’s orientation. In this research, a novel endoscopic capsule equipped with two internal electric motors is designed. This design concept is based on the capsule’s actuation using its motors’ reaction torques. The theoretical procedure and simulation show that the capsule could not reach every orientation using only one internal motor. It is shown that an orientation-controllable capsule needs two motors, which are necessary and sufficient for controlling the orientation of the active capsule in the intestine. Computer simulations and experiments have proven the desired performance and realization of the actuation mechanism. The developed actuation tool can align the capsule with the intestine; thus, the retained capsule can escape from where it is blocked.