Rfid spoilage sensor for packaged food and drugs

• US 20070176773A1
• Filed: 11/15/2002
• Published: 08/02/2007
• Est. Priority Date: 11/19/2001
• Status: Abandoned Application

• Current Assignee: Valtion Teknillinen Tutkimuskeskus
• Original Assignee: Valtion Teknillinen Tutkimuskeskus
• Inventors: Hurme, Eero, Smolander, Maria, Seppa, Heikki, Sammi, Jorma, Saari, Juha-Maiti, Majander, Pani, Suni, Ilkka, Varpuna, Timo
• Application Number:
  US10/495,927
• Publication Number:
  US 20070176773A1
• Time in Patent Office: Days
• US Class Current: 340/539.260
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 33/0044 Sulphides, e.g. H2S
• CPC Class Codes: G01N 33/0062 concerning the measuring method or the display, e.g. intermittent measurement or digital display
• CPC Class Codes: G01N 33/12 Meat; Fish
• CPC Class Codes: G06K 19/0717 the sensor being capable of sensing environmental conditions such as temperature history or pressure

Abstract

The present invention relates to a remotely readable sensor (22) for indication of usability condition of perishable products such as foodstuffs and medical drugs. The sensor incorporates an element responsive to the condition of the perishable product. According to the invention, the sensor (22) is placed inside the foodstuff package.

Claims

1. A remotely by RF techniques readable sensor (22) for indication of usability condition of perishable products such as foodstuffs and medical drugs, comprising

a sensor circuit (22) of a resonant LC circuit type incorporating

an element (12) responsive to the condition of said perishable product such that

the properties of said element change in a cumulative fashion as a function of a selected measurement variable,

characterized in that

said element (12) is such in which its electrical properties change cumulatively as a direct function of the degree of product spoilage either due to a reaction related to product spoilage or under the effect of oxygen or other undesirable gas or liquid.

2. The sensor (22) of claim 1, characterized in that said cumulatively changing element (12) is a resistor having a resistance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

3. The sensor (22) of claim 1 or 2, characterized in that said cumulatively changing element (12) is a capacitor having a capacitance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

4. The sensor (22) of claim 1 or 2, characterized in that said cumulatively changing element (12) is an inductive element having an inductance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

5. The sensor (22) of claim 1 characterized in that the functional material of said cumulatively changing element (12) is silver.

6. The sensor (22) of claim 1 characterized in that the functional material of said cumulatively changing element (12) is iron.

7. The sensor (22) of claim 1 characterized in that the functional material of said cumulatively changing element (12) is aluminum.

8. The sensor (22) of claim 1 characterized in that the functional material of said cumulatively changing element (12) is a redox-type indicator dye.

9. The sensor (22) of claim 1 characterized in that the functional material of said cumulatively changing element (12) is a conductive polymer.

10. The sensor (22) of claim 1 characterized in that the functional material of said cumulatively changing element (12) is copper.

11. A method of indicating usability condition of perishable products such as foodstuffs and medical drugs, in which method a sensor (22) remotely readable by RF techniques and capable of indicating the product condition is used for condition indication,

characterized in that

a sensor (22) is placed inside a foodstuff package.

12. The method of claim 11, characterized in that said sensor (22) incorporates a resonant LC circuit.

13. The method of claim 11 or 12, characterized in that said resonant LC circuit incorporates an element (12) whose electrical properties change cumulatively as a direct function of product spoilage or ambient oxygen content.

14. The method of claim 11 or claim 12, characterized in that said cumulatively changing element (12) is a resistor having a resistance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

15. The method of claim 11 or claim 12, characterized in that said cumulatively changing element (12) is a capacitor having a capacitance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

16. The method of claim 11 or claim 12, characterized in that said cumulatively changing element (12) is an inductive element having an inductance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

17. The method of claim 11, characterized in that the functional material of said cumulatively changing element (12) is silver.

18. The method of claim 11, characterized in that the functional material of said cumulatively changing element (12) is iron.

19. The method of claim 11, characterized in that the functional material of said cumulatively changing element (12) is aluminum.

20. The method of claim 11, characterized in that the functional material of said cumulatively changing element (12) is a redox-type indicator dye.

21. The method of claim 11, characterized in that the functional material of said cumulatively changing element (12) is a conductive polymer.

22. The method of claim 11, characterized in that the functional material of said cumulatively changing element (12) is copper.

23. A system for indicating usability condition of perishable products such as foodstuffs and medical drugs, the system incorporating a sensor (22) capable of indicating the product condition is used for condition indication,

said sensor (22) is a resonant LC circuit with cumulative indicator properties and adapted remotely readable by RF techniques, and

said system further includes an apparatus (12) for remote read of the properties of said sensor (22) using RF techniques,

characterized in that

said sensor (22) is placed inside a foodstuff package.

24. The system of claim 23, characterized in that said resonant LC circuit incorporates an element (12) whose electrical properties change cumulatively as a function of product spoilage or ambient oxygen content.

25. The system of claim 23 or 24, characterized in that said cumulatively changing element (12) is a resistor having a resistance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

26. The system of claim 23 or 24, characterized in that said cumulatively changing element (12) is a capacitor having a capacitance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

27. The system of claim 23 or 24, characterized in that said cumulatively changing element (12) is an inductive element having an inductance adapted to change cumulatively as a function of product spoilage or ambient oxygen content.

28. The system of claim 23, characterized in that the functional material of said cumulatively changing element (12) is silver.

29. The system of claim 23, characterized in that the functional material of said cumulatively changing element (12) is iron.

30. The system of claim 23, characterized in that the functional material of said cumulatively changing element (12) is aluminum.

31. The system of claim 23, characterized in that the functional material of said cumulatively changing element (12) is copper.

32. Use of RF-type sensor (22) inside a foodstuff or medical drug package for direct indication of spoilage or ambient oxygen content.