Asset location system

DETAILED DESCRIPTION The present invention provides an asset location system in which the infrastructure costs are reduced compared to asset tracking systems.
In the present system, a location tag (a controlled-range transmitter) is located at pre-determined locations.
Each asset includes an asset tag affixed to it, the asset tag receiving location information from the location tag.
The asset tag stores this location information and occasionally transmits its location and a unique identifier.
Preferably, the asset tag transmits using radio frequency while the location tag transmits through a means that has properties that can be well controlled spatially such as infrared or low-frequency radio.
An asset location retrieval unit is periodically moved throughout the facility and includes a receiver for receiving signals from each of the asset tags.
This information is stored and, preferably, is downloaded to a server which includes a searchable database.
A user can then search for an asset and will know, from the database, the last location identified by the asset location retrieval unit.
In a hospital setting, the asset location retrieval unit can be affixed to a cart which would normally be transported around the facility.
This could include, for example, a food or medicine cart.
The asset location retrieval unit can alternatively be transported around the facility by a person, or other means.
Once this cart is brought back to its original station, the retrieval unit can be connected to a network and information received during the cart's movement throughout the facility can be downloaded to the server.
Alternatively, the asset location retrieval unit can download its collected data wirelessly when a wireless link is (or can be) established and location data needs to be reported.
The asset tag can include a clock (or timekeeping system) so that the duration can be measured and reported for any of a) the duration for which a location tag remains detected, b) the duration for which a location tag is the most-recently detected location tag, or c) the duration since a location tag was last detected