Friday, February 1, 2013

Real Time Location System (RTLS)

I thought I write about the system which is really not a biomedical instrumentation but it helps to manage asset by tracking equipment location with ease by locating them during periodic maintenance or in times of clinical needs for the patients where equipment are needed from the various available locations. It can also manage equipment utilization by tracking their utilization time by areas where repurchasing of asset could be kept to a minimum through maximized use of the equipment, etc.


                                                             Figure by courtesy of Ekahau.

In this write-up, the standard wireless-based network 802.11 tracking technology is taken as a model for the function of real-time locating. Where the current hospital or institution wi-fi network already exists within the premises, it actually helps reduce the cost of implementation by piggy-back onto the existing wi-fi infrastructure. 

System Components

 Consisting of an positioning engine that runs on an application software to deliver the visibility of the assets and together with a web accessed Vision software and the required number of RFID active tags, the system with its multiple complex algorithms measures and verifies equipment location, location status over a single unified infrastructure. Active RFID tags wirelessly communicate with the positioning engine to determine the location, etc. 


Methodology


There are many methodology for performing range calculation and they include the following:
  • Angle of Arrival;
  • Time of Arrival;
  • Time Difference of Arrival (TDOA);
  • Received Signal Strength (RSS);
  • Time of Flight (ToF);
  • Symmetrical Double Sided Two Way Ranging (SDS-TWR).