Location Accuracy Estimates of an Ingested Wireless Endoscopy Capsule based on an RSSI Cost Function

The accurate location of an internal radio transmitter is important for long-term patient monitoring. An inverse solution for the surface field attenuation-based algorithm provides a simple position estimation but is degraded by noise and movement artefacts. Using the minimum cost function between the predicted and experimentally received signal strength indicators (RSSI) for four skin-surface receivers, the localization accuracy within 10 mm was achieved even with movement and external Gaussian noise. The relationship between RMSE value of each coordinate component in 3D under various noise levels provides a location accuracy estimate.