Interrogator and interrogation system employing the same

• US 7,893,840 B2
• Filed: 08/13/2007
• Issued: 02/22/2011
• Est. Priority Date: 03/03/2003
• Status: Expired due to Term

• Current Assignee: Lone Star SCM Systems, LP (f/k/a Medical I.P. Holdings, LP) (Incucomm Holdings Management, LLC)
• Original Assignee: Veroscan, Inc. (Tenet Healthcare Corporation)
• Inventors: Volpi, John P., Scott, Logan, Hensley, David W.
• Primary Examiner(s): Trieu, Van T.
• Application Number:
  US11/838,082
• Publication Number:
  US 20080018468A1
• Time in Patent Office: 1,289 Days
• Field of Search: 340/572.1, 340/572.4, 340/573.1, 340/573.2, 340/568.1, 340/10.1, 340/10.2, 340/10.3, 187/391, 187/394, 455/106, 342/51, 342/44, 342/42
• US Class Current: 340/572.4
• CPC Class Codes: A61B 2090/0805 automatically, e.g. by means of magnetic, optical or photoelectric detectors
• CPC Class Codes: A61B 90/98 using electromagnetic means, e.g. transponders
• CPC Class Codes: G01S 13/66 Radar-tracking systems; Analogous systems
• CPC Class Codes: G01S 13/825 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G06K 17/00 Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: H04Q 2209/47 using RFID associated with sensors
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RFID object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Claims

1. An interrogator, comprising:

a radio frequency identification (RFID) sensing subsystem configured to detect an RFID object; and

a control and processing subsystem configured to control an interrogation sequence of said RFID sensing subsystem by extending a precharging of said RFID object to provide adequate energy to charge an RFID tag of an otherwise undetectable RFID object prior to detecting said RFID object.

2. The interrogator as recited in claim 1 wherein said control and processing subsystem is configured to extend a duration of a continuous wave message of said interrogation sequence in accordance with precharging said RFID object.

3. The interrogator as recited in claim 1 wherein said control and processing subsystem varies an amplitude of a portion of said interrogation sequence.

4. The interrogator as recited in claim 1 wherein said control and processing subsystem is configured to control said interrogation sequence by sending a sequence of messages followed immediately by an interrogation command by said RFID sensing subsystem to detect said RFID object.

5. The interrogator as recited in claim 1 wherein said interrogation sequence comprises a continuous wave message, a data modulation message, a setup phase message and an unmodulated continuous wave message.

6. The interrogator as recited in claim 1 wherein said interrogation sequence comprises a continuous wave message, a data modulation message and a setup phase message having a first amplitude and an unmodulated continuous wave message having a second amplitude.

7. The interrogator as recited in claim 1 wherein said RFID sensing subsystem is configured to transmit an unmodulated continuous wave message and detect a modulated version of said continuous wave message from said RFID object, said control and processing subsystem configured to discern a presence of said RFID object from said modulated version of said continuous wave message and decode information from said RFID object.

8. A method of operating an interrogator, comprising:

controlling an interrogation sequence of a radio frequency identification (RFID) sensing subsystem by extending a precharging of said RFID object to provide adequate energy to charge an RFID tag of an otherwise undetectable RFID object with a control and processing subsystem; and

detecting said RFID object.

9. The method as recited in claim 8 wherein said controlling includes extending a duration of a continuous wave message of said interrogation sequence.

10. The method as recited in claim 8 wherein said controlling includes varying an amplitude of a portion of said interrogation sequence.

11. The method as recited in claim 8 wherein said controlling includes sending a sequence of messages followed immediately by an interrogation command by said RFID sensing subsystem to detect said RFID object.

12. The method as recited in claim 8 wherein said interrogation sequence comprises a continuous wave message, a data modulation message, a setup phase message and an unmodulated continuous wave message.

13. The method as recited in claim 8 wherein said interrogation sequence comprises a continuous wave message, a data modulation message and a setup phase message having a first amplitude and an unmodulated continuous wave message having a second amplitude.

14. The method as recited in claim 8, further comprising:

transmitting an unmodulated continuous wave message and said detecting includes detecting a modulated version of said continuous wave message from said RFID object;

discerning a presence of said RFID object from said modulated version of said continuous wave message; and

decoding information from said RFID object.

15. An interrogation system, comprising:

a radio frequency identification (RFID) object; and

an interrogator configured to detect said RFID object and control an interrogation sequence of said interrogator by extending a precharging of said RFID object to provide adequate energy to charge an RFID tag of an otherwise undetectable RFID object prior to detecting said RFID object.

16. The interrogation system as recited in claim 15 wherein said interrogator is configured to extend a duration of a continuous wave message of said interrogation sequence in accordance with precharging said RFID object.

17. The interrogation system as recited in claim 15 wherein said interrogator varies an amplitude of a portion of said interrogation sequence.

18. The interrogation system as recited in claim 15 wherein said interrogator is configured to control said interrogation sequence by sending a sequence of messages followed immediately by an interrogation command by said interrogator to detect said RFID object.

19. The interrogation system as recited in claim 15 wherein said interrogation sequence comprises a continuous wave message, a data modulation message, a setup phase message and an unmodulated continuous wave message.

20. The interrogation system as recited in claim 15 wherein said interrogator is configured to transmit an unmodulated continuous wave message and detect a modulated version of said continuous wave message from said RFID object, said interrogator being configured to discern a presence of said RFID object from said modulated version of said continuous wave message and decode information from said RFID object.