Linearized Transformation of RF Data for Capsule Tracking in Wireless Telemetry

In this paper, we discuss system and method of determining the real-time location of an omnidirectional 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, we assume omnidirectional transmitter transmitting at 433 MHz, Input power 1 W, and Es/No = 20 dB (corresponding to the linear region of the target transceiver). We also discuss the method for using the original analogue signal, after conversion to voltage, for position tracking. In our 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.