An inventory management system is provided that includes an RFID interrogator and corresponding RFID tags that are placed on items to be monitored. The tags can be used to monitor the storage time of food items stored in a refrigerator or pantry, the time in use of replaceable items such as toilet bowl...http://www.google.de/patents/US7680691?utm_source=gb-gplus-sharePatent US7680691 - Inventory management system using RFID
