Locomotion Analysis of an Inchworm-Like Capsule Robot in the Intestinal Tract.

Abstract

Inchworm-like locomotion is one of the most common and effective approaches for exploring the intestinal tract. Here, we present a locomotion analysis for a typical inchworm-like capsule robot, which is composed of a locomotion unit and some functional modules that are installed at both ends. The locomotion unit consists of two clampers at both ends and an extensor at midsection, and the functional modules include the camera, microtools for diagnosis or therapy, etc. By taking into account the intestinal deformation induced by the robot's action in every continuous locomotion step, a locomotion model correlating the locomotion efficiency with the design parameters (i.e., the periodic stroke, the lengths of the clampers, extensor, and functional modules) was built. Ex vivo experiments were conducted to validate the proposed model, and the experimental results basically agreed to the theoretical ones predicted by the model. The proposed locomotion model is effective in guiding the selection of the design parameters for improving the locomotion efficiency. The inchworm-like capsule robot with higher locomotion efficiency will enable a more efficient diagnosis and therapy process for the intestinal tract.