US 7,321,296 B2
Electronic locating systems
Thomas J. Engellenner, 11 Birch Hill Rd., Newton, Mass. 02465 (US)
Assigned to Thomas J. Engellenner, Newton, Mass. (US)
Filed on May 09, 2005, as Appl. No. 11/124,844.
Application 11/124844 is a continuation of application No. 10/145516, filed on May 14, 2002, granted, now 6,891,469.
Application 10/145516 is a continuation of application No. 09/562247, filed on May 02, 2000, granted, now 6,388,569.
Application 09/562247 is a continuation of application No. 09/134790, filed on Aug. 14, 1998, granted, now 6,057,756.
Application 09/134790 is a continuation of application No. 08/478866, filed on Jun. 07, 1995, granted, now 5,798,693.
Prior Publication US 2005/0206523 A1, Sep. 22, 2005
Int. Cl. G08B 26/00 (2006.01)
U.S. Cl. 340—505  [235/385; 340/10.31; 340/10.33; 340/825.49; 705/28] 7 Claims
OG exemplary drawing
 
1. A method of tracking the distribution of items comprising the steps of:
coding each item to be distributed with a tag responsive to a predetermined electromagnetic signal, said coded tag providing an identification of the item;
creating an initial interrogation region at an exit passageway from an initial location such that uncoded or improperly coded tags are detected before distribution;
interrogating a spatial region at a destination location with said electromagnetic signal to cause the tag to generate a responsive signal if present at the destination location;
detecting said responsive signal to confirm the tagged item's presence; and
updating an inventory of items at the destination location to include the responsive tagged item.