RFID tag inlay for incontinence detection pad

• US 10,716,715 B2
• Filed: 08/23/2018
• Issued: 07/21/2020
• Est. Priority Date: 08/29/2017
• Status: Active Grant

• Current Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Original Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Inventors: Severns, Ryan S., Voll, James D., Knittle, Brett A., Monson, Gavin M., Harmeyer, John V., Lachenbruch, Charles A., Sauser, Frank E., Canter, Joseph T., Fu, Yongji, Emmons, Kirsten M., Ribble, David L., Wiggermann, Neal, Christie, John D., Tallent, Dan R., Nusair, Marwan, Koors, Edward J.
• Primary Examiner(s): Cyr, Daniel St
• Application Number:
  US16/110,603
• Publication Number:
  US 20190060137A1
• Time in Patent Office: 698 Days
• Field of Search: 235492, 235487
• CPC Class Codes: A61F 13/15203 Properties of the article, e.g. stiffness or absorbency chemical aspects A61L15/00
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm
• CPC Class Codes: A61F 2013/424 having an electronic device
• CPC Class Codes: G06K 19/0709 the source being an interrogation field
• CPC Class Codes: G06K 19/07745 Mounting details of integrated circuit chips
• CPC Class Codes: G06K 7/10158 methods and means used by the interrogation device for reliably powering the wireless record carriers using an electromagnetic interrogation field
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037

Abstract

An absorbent article has one or more fluid filter layers to inhibit electrode traces from being exposed to low volumes of fluid to reduce the number of false positives that are indicated by an RFID tag of the incontinence detection pad. An antenna inlay has a sacrificial trace portion to permit testing for proper operation of an RFID chip electrically coupled to the antenna inlay. After testing, the sacrificial trace portion is severed. A fluid barrier layer blocks fluid from reaching portions of electrode traces that are located on a backsheet outside a periphery of an absorbent core of an incontinence detection pad. The power at which an antenna transmits to wirelessly energize a passive RFID tag of an incontinence detection pad is controlled to reduce the number of false positives indicated by the RFID tag.

Claims

1. An antenna inlay of an RFID tag, the antenna inlay comprising

an antenna portion,

a first electrical contact portion,

a second electrical contact portion, the first electrical contact portion comprising a first electrical lead having a first gap formed therein to provide a first lead segment and a second lead segment, and

a first resistor placed across the gap to electrically interconnect the first and second lead segments,

wherein the antenna inlay is provided in an absorbent article comprising a topsheet made of a fluid permeable material, a backsheet comprising a first layer of fluid impermeable material, a conductive ink pattern provided above the first layer and configured to form a first electrode trace and a second electrode trace, a passive radio frequency identification (RFID) tag including the antenna inlay and attached to the first layer such that the first and second electrical contact portions couple to the first and second electrode traces, an absorbent core situated between the topsheet and the backsheet, and a fluid filter layer situated so as to inhibit a low volume of fluid from being able to reach the first and/or second electrode traces beneath the absorbent core, wherein after fluid of a sufficient volume greater than the low volume has passed through the topsheet, the absorbent core, and the fluid filter layer, an electrical pathway is formed between the first and second electrode traces by the fluid which enables the passive RFID tag to emit a signal indicating an incontinence event has occurred in response to the passive RFID tag being excited by external energy.

2. The antenna inlay of claim 1, wherein the second electrical contact portion comprises a second electrical lead having a second gap formed therein to provide a third lead segment and a fourth lead segment, and further comprising a second resistor placed across the second gap to electrically interconnect the third and fourth lead segments.

3. The antenna inlay of claim 2, wherein the second electrical contact portion is configured as a mirror image of the first electrical contact portion.

4. The antenna inlay of claim 2, wherein the antenna portion comprises a first antenna patch and a second antenna patch.

5. The antenna inlay of claim 4, wherein the second antenna patch is configured as a mirror image of the first antenna patch.

6. The antenna inlay of claim 2, wherein the antenna portion, first electrical contact portion, and the second electrical contact portion are coplanar.

7. The antenna inlay of claim 2, wherein the antenna portion, first electrical contact portion, and the second electrical contact portion comprise a metallic film.

8. The antenna inlay of claim 7, wherein the metallic film comprises aluminum.

9. The antenna inlay of claim 7, wherein a thickness of the metallic film is about 9 micrometers (μ

m).

10. The antenna inlay of claim 2, wherein the first resistor and the second resistor have substantially equivalent resistances or wherein the first resistor and the second resistor have different resistances.

11. The antenna inlay of claim 10, wherein the resistance of at least one of the first and second resistors comprises about 2.4 Mega Ohms (MΩ

).

12. The antenna inlay of claim 1, wherein the antenna portion comprises a first antenna patch and a second antenna patch.

13. The antenna inlay of claim 12, wherein the second antenna patch is configured as a mirror image of the first antenna patch.

14. The antenna inlay of claim 1, wherein the antenna portion, first electrical contact portion, and the second electrical contact portion are coplanar.

15. The antenna inlay of claim 1, wherein the antenna portion, first electrical contact portion, and the second electrical contact portion comprise a metallic film.

16. The antenna inlay of claim 15, wherein the metallic film comprises aluminum.

17. The antenna inlay of claim 15, wherein a thickness of the metallic film is about 9 micrometers (μ

m).

18. An antenna inlay of an RFID tag, the antenna inlay comprising

an antenna portion,

a first electrical contact portion,

a second electrical contact portion, the first electrical contact portion comprising a first electrical lead having a first gap formed therein to provide a first lead segment and a second lead segment, and

a first resistor placed across the gap to electrically interconnect the first and second lead segments,

wherein the antenna inlay is used in a method of controlling an incontinence detection system, the method comprising establishing a first reader antenna of a plurality of reader antennae as a transmit antenna that is used to wirelessly energize a passive RFID tag of an absorbent article at a first power level, the passive RFID tag including the antenna inlay of claim 1, wherein the plurality of reader antennae comprises N spaced apart reader antennae, wherein N is an integer equal to or greater than three, establishing each of the plurality of reader antennae, except for the first reader antenna, as receive reader antennae that each listen for backscattered data emitted from the passive RFID tag, and reducing the first power level to a second power level if the receive reader antennae that are able to read the backscattered data exceeds a predetermined number of receive reader antennae, the predetermined number being less than N−

1.

19. The antenna inlay of claim 18, wherein the method further comprises analyzing signal to noise ratio between the transmit antenna and each of the receive antenna before reducing the first power level to the second power level.

20. The antenna inlay of claim 18, wherein the method further comprises analyzing a receive signal level (RSL) figure of merit (FoM) of the backscattered data before reducing the first power level to the second power level.

21. The antenna inlay of claim 20, wherein the RSL FoM of multiple emissions of backscattered data are averaged before reducing the first power level to the second power level.

22. The antenna inlay of claim 18, wherein the method further comprises determining that an external power flag is set in the backscattered data before reducing the first power level to the second power level.

23. The antenna inlay of claim 18, wherein the predetermined number of receive antennae comprises two receive antennae.

24. The antenna inlay of claim 18, wherein the predetermined number of receive antennae comprises one receive antenna.

25. The antenna inlay of claim 18, wherein the first power level and the second power level lie within a range of about +20 decibel milliWatt (dBm) to about +33 dBm.

26. The antenna inlay of claim 18, wherein the method further comprises cycling through the plurality of antennae as being established as the transmit antenna with each of the remaining antennae of the plurality of antennae being established as the receive antenna for a period of time.

27. The antenna inlay of claim 26, wherein the plurality of antennae are coupled to a bistatic radio frequency (RF) switch matrix which is operable to establish which antenna of the plurality of antennae is the transmit antenna and to establish which antenna of the plurality of antennae is the receive antenna.

28. The antenna inlay of claim 27, wherein the method further comprises operating the bistatic RF switch matrix to cause the transmit antenna to transmit using a frequency hopping scheme.

29. The antenna inlay of claim 28, wherein the frequency hopping scheme uses 50 distinct frequencies, with each frequency being used only once in a pseudo-random order before any of the 50 frequencies are repeated.

30. The antenna inlay of claim 29, wherein the 50 frequencies lie within a range between about 902 MegaHertz (MHz) and 928 MHz.

31. An antenna inlay of an RFID tag, the antenna inlay comprising

an antenna portion,

a first electrical contact portion,

a second electrical contact portion, the first electrical contact portion comprising a first electrical lead having a first gap formed therein to provide a first lead segment and a second lead segment, and

a first resistor placed across the gap to electrically interconnect the first and second lead segments,

wherein the antenna inlay is provided in an absorbent article comprising a substrate, a first electrode on the substrate, a second electrode on the substrate, the second electrode being spaced from the first electrode, circuitry coupled to the first and second electrodes, the circuitry including the antenna inlay, the circuitry being operable to monitor whether a biofluid is present on the substrate by determining whether the first and second electrodes are in an open circuit configuration or a closed circuit configuration, the open circuit configuration being indicative of an absence of biofluid and a closed circuit configuration being indicative of a presence of biofluid, and a plurality of high wick bridges interconnecting the first and second electrodes.

32. The antenna inlay of claim 31, wherein the antenna portion comprises a first antenna patch and a second antenna patch.

33. The antenna inlay of claim 32, wherein the second antenna patch is configured as a mirror image of the first antenna patch.

34. The antenna inlay of claim 31, wherein the antenna portion, first electrical contact portion, and the second electrical contact portion are coplanar.

35. The antenna inlay of claim 31, wherein the antenna portion, first electrical contact portion, and the second electrical contact portion comprise a metallic film.

36. The antenna inlay of claim 35, wherein the metallic film comprises aluminum.

37. The antenna inlay of claim 35, wherein a thickness of the metallic film is about 9 micrometers (μ

m).

38. The antenna inlay of claim 31, wherein the first electrode includes a generally straight first segment, the second electrode includes a generally straight second segment, and at least some of the high wick bridges include a generally straight main segment that is substantially perpendicular to the first and second segments.

39. The antenna inlay of claim 31, wherein the at least some of the high wick bridges include a series of hash segments that are substantially perpendicular with the main segment.

40. The antenna inlay of claim 39, wherein the main segment bisects each of the hash segments.

41. The antenna inlay of claim 39, wherein the hash segments are of substantially equivalent lengths.

42. The antenna inlay of claim 41, further comprising a hydrophobic material situated within each of a plurality of zones bounded by respective portions of the first and second electrodes and by respective pairs of adjacent high wick bridges.

43. The antenna inlay of claim 42, wherein the hydrophobic material comprises a hydrophobic coating.

44. The antenna inlay of claim 42, wherein the hydrophobic material in at least some of the zones is quadrilateral in shape.

45. The antenna inlay of claim 42, wherein each of the high wick brides includes a main segment and a series of hash segments extending across the main segment, wherein ends of the hash segments terminate at or in close proximity to a respective boundary of the hydrophobic material in each zone.

46. The antenna inlay of claim 31, wherein the RFID tag comprises a passive RFID tag.