Integrated Design and Decoupled Control of Anchoring and Drug Release for Wireless Capsule Robots

Abstract

This article proposes a novel targeted-location drug delivery system for lower gastrointestinal (GI) tract (such as the small intestine) capsule robots. The proposed system takes a “2-in-1” approach that enables both the magnetically actuated anchoring and drug release by using only one internal magnet. The integrated design consists of a magnetically actuated decoupling module, an anchoring module, and a drug release module. The magnetically actuated decoupling module is equipped with two decoupling mechanisms at both ends, which can, respectively, provide one-way rotation for anchoring and drug release functions. The two functions can be decoupled controlled. The anchoring module can simultaneously extend two C-shaped anchoring legs, which can help the capsule anchor at a given position inside the GI tract without damaging it. The drug release module can load 1.6-mL liquid drug and quickly release all the drugs under the control of an external magnet. A capsule robot prototype of the proposed design has been built with 16-mm diameter and 50-mm length. Phantom and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vitro</i> experiments on anchoring and drug release modules have been conducted and have validated the effectiveness of the proposed design and control method.