Physiological Factors of the Small Intestine in Design of Active Capsule Endoscopy

Wireless capsule endoscope is a device used to examine the diseases in the small intestine. At present, the capsule endoscope moves through the gastrointestinal tract by natural propulsion of peristalsis. In order to achieve real-time diagnosis and treatment-related procedure, the capsule endoscope is required to be self-actuated and controlled. Different from soild environment, the small intestine is an extremely flexible tube. The unique structure and tissue cause many challenges for the capsule actuation. In this paper, the features, motility, and frictional force of the small intestine are analyzed for determining the design strategy. In-vitro experiment results show the power of magnetic force needed for driving the capsule and the factors that affect the magnitude of the driving force as well. Based on the analysis of the small intestime, a scheme of magnetically-actuated active endoscopy is proposed in the end.