Method and apparatus to detect transponder tagged objects, for example during medical procedures

• US 9,730,850 B2
• Filed: 11/03/2014
• Issued: 08/15/2017
• Est. Priority Date: 10/28/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Barnes, Bruce E., Poirier, David A., Blair, William A.
• Primary Examiner(s): Zimmerman, Brian
• Assistant Examiner(s): SAMSON, SARA B
• Application Number:
  US14/531,932
• Publication Number:
  US 20150054625A1
• Time in Patent Office: 1,016 Days
• CPC Class Codes: A61B 90/90 Identification means for patients or instruments, e.g. tags
• CPC Class Codes: A61B 90/98 using electromagnetic means, e.g. transponders
• CPC Class Codes: A61G 13/10 Parts, details or accessories surgical drape sheets A61B46/00
• CPC Class Codes: A61G 13/1265 having inflatable chambers
• CPC Class Codes: A61G 13/127 having chambers filled with liquid or gel
• 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: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10128 the step consisting of detection of the presence of one or more record carriers in the vicinity of the interrogation device
• CPC Class Codes: H01Q 21/00 Antenna arrays or systems arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system H01Q3/00
• CPC Class Codes: H01Q 5/00 Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements combinations of separate active antenna units operating in different wavebands and connected to a common feeder system H01Q21/30
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

The presence or absence of objects (e.g., medical implements, medical supplies) tagged with transponders may be determined in an environment in which medical procedures (e.g., surgery) are performed via an interrogation and detection system which includes a controller and a plurality of antennas positioned along a patient support structure. The antennas may, for example, be positioned along an operating table, bed, a mattress or pad or a sheet and may be radiolucent. Respective antennas may successively be activated to transmit interrogation signals. Multiple antennas may be monitored for responses from transponders to the interrogation signals. For example, all antennas other than the antenna that transmitted the most recent interrogation signal may be monitored.

Claims

1. An apparatus to detect transponder tagged objects which are used in performing medical procedures, the apparatus comprising:

a plurality of antennas spaced at fixed positions along at least a portion of a length of a patient support structure that is sized to support a patient, at least one of the antennas having a measurable physical characteristic that varies in response to a physical force applied to the at least one of the antennas; and

a control system communicatively coupled to the antennas to activate respective ones of at least two of the antennas to transmit respective interrogation signals, to detect a response signal generated by a transponder responsive to the interrogation signals, and to detect a value indicative of the measurable physical characteristic that varies in response to the physical force applied to the at least one of the antenna.

2. The apparatus of claim 1 wherein the measurable physical characteristic that varies in response to a physical force applied to the at least one of the antennas is a resistance of the antenna, which indicates an amount of strain at the position of the antenna on the patient support structure.

3. The apparatus of claim 1 wherein a number of the plurality of antennas are electrically coupled in at least one bridge configuration.

4. The apparatus of claim 3 wherein the at least one bridge configuration is a Wheatstone bridge configuration.

5. The apparatus of claim 1 wherein the control system further provides an alert in response to the measurable physical characteristic exceeding a threshold value.

6. The apparatus of claim 5 wherein the control system further provides an indication of a location on the patient support structure where the measurable physical characteristic has exceeded the threshold value.

7. The apparatus of claim 1 wherein the value indicative of the measurable physical characteristic is indicative of at least one of an amount of strain, an amount of force or an amount of pressure.

8. The apparatus of claim 1 wherein the patient support structure comprises a surgical table or a bed.

9. The apparatus of claim 1 wherein the control system sequentially activates respective ones of the antennas to transmit respective interrogation signals and detects via the antennas other than a most recently activated one of the antennas the response signal generated by the transponder responsive to a most recent one of the interrogation signals.

10. A method to detect transponder tagged objects which are used in performing medical procedures, the method comprising:

for a plurality of antennas spaced at fixed positions along at least a portion of a length of a patient support structure that is sized to support a patient,

activating respective ones of at least two of the antennas to transmit respective interrogation signals,

detecting through the antennas a response signal generated by a transponder responsive to the interrogation signals, and

detecting a measurable physical characteristic that varies in response to a physical force applied to at least one of the plurality of antennas.

11. The method of claim 10 wherein detecting a measurable physical characteristic that varies in response to a physical force applied to the at least one of the plurality of antennas comprises detecting a change in a resistance of each antenna.

12. The method of claim 10 further comprising providing an alert in response to a value of the detected measurable physical characteristic equaling or exceeding a threshold value.

13. The method of claim 12 further comprising providing an indication of a location on the patient support structure where the value of the detected measurable physical characteristic has equaled or exceeded the threshold value.

14. The method of claim 10 wherein detecting a measurable physical characteristic that varies in response to a physical force applied to the at least one of the plurality of antennas comprises detecting a physical characteristic indicative of at least one of a strain, a force or a pressure applied to the antenna.

15. The method of claim 10 wherein activating respective ones of at least two of the antennas to transmit respective interrogation signals and detecting through the antennas a response signal generated by a transponder responsive to the interrogation signals comprises sequentially activating respective ones of the antennas to transmit respective interrogation signals and detecting via the antennas other than a most recently activated one of the antennas the response signal generated by the transponder responsive to a most recent one of the interrogation signals.