Adaptive Linearized Methods for Tracking a Moving Telemetry Capsule

In this paper, we discuss system and method of determining the real-time location of an omni-directional diagnostic radio frequency (RF) system while the object (transmitter) is moving freely inside an inaccessible organ. A specific application to the human gastrointestinal (GI) organ is presented, showing the importance of the method in accessing a specific site for drug administration or for extracting fluid or tissue samples for biopsy and similar medical investigations. For practical purposes, omnidirectional antenna on the transmitter at 433 MHz, normalized transmitter power 1 W was modeled for simplicity, and Es/No = 20 dB (corresponding to the linear region of the target transceiver). A brief discussion of how the original analogue signals, after conversion to voltage, was adapted for position tracking. In the tracking algorithm, we employed a path loss scenario based on the popular log-normal model to simulate the effects of organs on signal quality between transmitter and receiver at various distances.