Patent ID: 8384545

Claim:
A medical article tracking system for reading a data carrier that is attached to a medical article, the data carrier being responsive to electromagnetic energy (EM) of a frequency f 1 in response to which the data carrier provides identification data, the system comprising: a metallic enclosure having an internal storage area, the metallic enclosure further having electrically conductive walls that completely surround the internal storage area and any medical article with associated data carrier placed therein, the enclosure having a natural frequency of resonance f 2 which is different from f 1 and to which a data carrier that is responsive to frequency f 1 is not responsive; a probe disposed at a metallic wall of the metallic enclosure within the metallic enclosure, the probe configured to inject electromagnetic energy of a frequency f 1 into the metallic enclosure, wherein the position of the probe in relation to the metallic walls of the metallic enclosure is selected so that reflected EM of frequency f 1 within the metallic enclosure is in phase at the probe position to thereby optimize power transfer at frequency f 1 into the enclosure; an active impedance matching circuit coupled to the probe and configured to actively more closely match impedance of the probe to impedance of the metallic enclosure at frequency f 1 ; a storage device located within the internal storage area of the metallic enclosure configured to receive a medical article with an associated data carrier that is responsive to EM at frequency f 1 ; and a receiving antenna disposed within the metallic enclosure and configured to receive the identification data provided by the data carrier.