Adaptive Simultaneous Magnetic Actuation and Localization for WCE in a Tubular Environment

TL;DR

This paper introduces an adaptive SMAL system for wireless capsule endoscopy that enhances propulsion and localization accuracy in complex tubular environments through sensor optimization and real-time pose estimation.

Contribution

It presents a novel adaptive mechanism for sensor activation and an improved real-time 6-D pose estimation method tailored for magnetic capsule navigation.

Findings

Achieves high localization accuracy and update frequency.

Demonstrates improved actuation efficiency and workspace size.

Validates system performance through extensive phantom and ex-vivo experiments.

Abstract

Simultaneous Magnetic Actuation and Localization (SMAL) is a promising technology for active wireless capsule endoscopy (WCE). In this paper, an adaptive SMAL system is presented to efficiently propel and precisely locate a capsule in a tubular environment with complex shapes. In order to track the capsule with high localization accuracy and update frequency in a large workspace, we propose a mechanism that can automatically activate a sub-array of sensors with the optimal layout during the capsule movement. The improved multiple objects tracking (IMOT) method is simplified and adapted to our system to estimate the 6-D pose of the capsule in real time. Also, we study the locomotion of a magnetically actuated capsule in a tubular environment, and formulate a method to adaptively adjust the pose of the actuator to improve the propulsion efficiency. Our presented methods are applicable to other permanent magnet-based SMAL systems, and help to improve the actuation efficiency of active WCE. We verify the effectiveness of our proposed system in extensive experiments on phantoms and ex-vivo animal organs. The results demonstrate that our system can achieve convincing performance compared with the state-of-the-art ones in terms of actuation efficiency, workspace size, robustness, localization accuracy and update frequency.