US Patent 7092789 Controlled inventory device and method using pressure transducer

A method and apparatus for controlled dispensing of consumable supply items, such as office supplies, wherein the quantity of items added or removed from the apparatus is determined by sensing a change in weight of items within the apparatus. The apparatus may be in the form of a cabinet having a plurality of doors, each door having a secured position preventing access to the items within the cabinet. The cabinet may be configured to unlock less than all of the doors to allow limited access to the items based on various factors, such as user identification and item cost.