Wireless Localization for a Capsule Endoscopy: Techniques and Solutions

A wireless capsule endoscopy is a noninvasive medical device designed for human gastrointestinal tract diagnosis. The localization function of the capsule provides a real‐time monitoring on the capsule movement, which can detect the retention at an early stage. The static magnetic localization system requires little power consumption, and it is easy to transform the system structure into a wearable system for capsule endoscopy. This chapter discusses the challenges and possible solutions of the magnetic localization. The DC signal measured in the static magnetic localization suffers from the static noise interference in the environment. One of the methods to avoid DC interference is to modulate the information to a certain frequency, where the alternating magnetic field is adopted. The chapter also discusses the aspects of challenges and corresponding solutions, including the model of the target magnet, the adaptive noise cancellation, the calculation of the position retrieval algorithm, and the impact of the placement of sensors.