RSSI based localization and tracking of medical diagnostic sensors.

摘要

We consider the problem of identifying the location of a diagnostic capsule in the gastrointestinal (GI) tract. We developed an estimation algorithm that utilizes radio frequency signals converted to voltage on the received signal strength indicator (RSSI) output of an array of transceivers. We employed a modified form of the traditional radio-map based deterministic model that requires an estimate of initial position vector. Trilateration was used to determine the 2-D coordinates of unknown locations by linearizing the resulting linear least squares equations. A final algorithm based on non linear least squares approximation and the Newton's iteration was used to generate a more accurate position coordinates. Results from our preliminary experiments shows that the method presented is accurate to determine the real-time position of a moving object by using RSSI signals to within 25percent.