SYSTEM AND METHOD USING FREQUENCY HOPPING TO IDENTIFY ITEMS TAGGED WITH RFID TAGS IN AN ENCLOSED SPACE

摘要

A system and method comprises a plurality of RF antennas having beams directed to a storage space in which medical items having RFID tags are stored. Each antenna is controlled to inject energy at a different frequency in a frequency-hopping set of frequencies to activate the tags. The return signal strength is monitored and for each tag that responds, the antenna location, frequency of the injected energy, identification response, and signal strength are stored as identification data. If a tag fails to respond in new scans, the antenna at which the tag last responded receives all the frequency-hopping frequencies in an attempt to locate the tag. If new tags are found, they are compared to a list of expected new medical items.

主权项

1. A wireless automated reader system to identify medical items having a data carrier associated with them by reading the data carriers, the data carriers transmitting identification signals in response to being activated by electromagnetic energy (“EM energy”) of a predetermined range of frequencies, the medical items being stored in a storage space of an enclosure, the system comprising:
a plurality of reader antennas located at different positions, each of which has a beam directed into the storage space of the enclosure for activating data carriers of items residing in the storage space and receiving identification signals transmitted by the activated data carriers; a processor having a memory; an energy source having a plurality of different frequency-hopping frequencies each frequency of which is within the predetermined range of frequencies to which the data carriers respond with transmitted identification signals, the energy source being responsive to control signals to provide a set of a plurality of injection signals to selected reader antennas, the injection signals having different frequency-hopping frequencies; and; an antenna controller adapted to provide control signals to the energy source to cause the energy source to deliver the set of a plurality of injection signals having different frequency-hopping frequencies to the plurality of reader antennas and to cycle through the plurality of injection signals having different frequency-hopping frequencies; wherein, the processor is programmed to receive the identification signals received by the antennas and store in the memory the identification signals as a data scan associated with a particular time; and wherein the processor is further programmed to compare the identification signals generated in a present data scan to identification signals previously generated and stored in the memory of a prior data scan to determine if any medical items are missing or have been added between the prior data scan and the present data scan.