On the accuracy of RF and image processing based hybrid localization for wireless capsule endoscopy

Abstract

RF based and image processing based hybrid localization for wireless capsule endoscopy (WCE) has been adopted as one of the leading in-body localization approach for its overwhelming advantage on the accuracy of location estimation. In this paper, in order to investigate the fundamental limits, we derived the 3-dimensional (3D) Posterior Cramer-Rao Lower Bound (PCRLB) for hybrid WCE localization with the knowledge of RF based range estimation and image processing based step length and heading measurements. In addition to the PCRLB derivation, numerical results of this work shows that when the accuracy of image processing based measurement is high enough or the number of on-body RF receiver is large enough, the root-mean-square error (RMSE) of hybrid WCE localization can be limited within 3cm.