Design, Implementation, and Fundamental Limits of Image and RF Based Wireless Capsule Endoscopy Hybrid Localization.

Precise localization of Wireless Capsule Endoscopy (WCE) inside the curly, long, and compact small intestine remains a challenging problem facing researchers for more than a decade. Conventional Radio Frequency (RF) localization techniques, commonly used in outdoor and indoor area, have demonstrated a few centimeters accuracy when applying to the inside of human body. In this paper, using 3D Posterior Cramer-Rao Lower Bound (PCRLB) as a framework for performance evaluation, we demonstrated that millimetric accuracy can be achieved using hybrid RF and image processing localization technique. This level of accuracy enables precise simultaneous localization and mapping of the WCE movement path inside the small intestine. Using the PCRLB framework, we provided in-depth analysis on hybrid localization performance regarding the effects of WCE movement estimation, the effects of system bandwidth as well as the effects of on-body sensor numbers and placements.