Accuracy of endoscopic capsule localization using position bounds on smoothed path loss based WCL

Abstract

Accurate localization of Wireless video capsule endoscope (VCE) is a crucial requirement for proper diagnosis of intestinal abnormalities. A major challenge in RF based localization is the shadow fading and multi-path propagation effects of non-homogeneous medium of human body which causes high random deviations in the measured path loss resulting in high localization error. To address the randomness issue of the scattered path loss, we propose Savitzky-Golay filtering to estimate the smoothed path loss. Then we estimate the positions of the moving capsule using weighted centroid localization (WCL) algorithm by finding the weighted average of the sensor's position. We compute the weight of the sensor receivers position using degree based estimated smoothed path loss. Finally, we propose two position bounds on the estimated positions to improve the accuracy of localization and verify the accuracy using different performance metrics. To validate our proposed algorithm, we develop a simulation platform using MATLAB and observe significant improvement over the literature using our proposed position bounded smoothed path loss based WCL without any prior knowledge of channel parameters or distance.