Autonomous Magnetic Navigation Framework for Active Wireless Capsule Endoscopy Inspired by Conventional Colonoscopy Procedures

In recent years, simultaneous magnetic actuation and localization (SMAL) for active wireless capsule endoscopy (WCE) has been intensively studied to improve the efficiency and accuracy of gastrointestinal (GI) examination using WCE. In this letter, we draw inspiration from the conventional colonoscopy procedures and propose an autonomous navigation framework for active WCE based on SMAL technologies, in order to realize efficient and accurate navigation of a robotic capsule endoscope in unknown tubular environments (e.g., intestines) with minimal user effort. First, the capsule is actuated to explore the unknown tubular environment using an automatic propulsion algorithm, and a viable path to represent the environment is generated. Then, the capsule is navigated towards any user-selected point on the trajectory using a trajectory following algorithm, to allow accurate and repeated inspections of suspicious lesions. We implement the navigation framework on a robotic system incorporated with advanced SMAL algorithms, and validate it in the navigation experiments in various tubular environments including phantoms and ex-vivo pig colons. Our results demonstrate that the proposed framework can effectively navigate the capsule in unknown, complex tubular environments with a satisfactory accuracy, repeatability and efficiency.