Methods and Devices for Determining Sensing Device Usability

• US 20130002279A1
• Filed: 06/29/2012
• Published: 01/03/2013
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Abbott Point Of Care Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Point Of Care Incorporated (Abbott Laboratories)
• Inventors: Martin, Glenn, Zhao, Tian-Xian, Breeze, Steven, Jeffrey, Craig, Snyder, Stephen Lee
• Granted Patent: US 9,224,312 B2
• Time in Patent Office: Days
• US Class Current: 324/750.3
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771
• CPC Class Codes: G09F 3/0291 Labels or tickets undergoing a change under particular conditions, e.g. heat, radiation, passage of time

Abstract

Methods and devices for determining sensing device usability, e.g., for point of care immunoassay devices. In one embodiment, the invention is to a method of determining device usability, comprising the steps of providing a device comprising a first electrical pad; a second electrical pad; and a continuous polymer layer contacting at least a portion of the first and second electrical pads; applying a potential across the first and second electrical pads; measuring an electrical property associated with the continuous polymer layer; and determining whether the measured electrical property associated with the continuous polymer layer has exceeded a threshold level associated with the device usability.

Claims

1. A method of determining device usability, comprising the steps of:

providing a device comprising a first electrical pad;

a second electrical pad; and

a continuous polymer layer contacting at least a portion of the first and second electrical pads;

applying a potential across the first and second electrical pads;

measuring an electrical property associated with the continuous polymer layer; and

determining whether the measured electrical property associated with the continuous polymer layer has exceeded a threshold level associated with the device usability.

2. The method of claim 1, wherein the polymer layer comprises a polymer matrix, a plasticizer and an organic salt.

3. The method of claim 2, wherein the polymer layer comprises from 20 to 40 wt. % polymer matrix.

4. The method of claim 2, wherein the polymer matrix comprises a polymer selected from the group consisting of polyvinyl chloride, polyurethane, polyvinylacetate, carboxylated PVC, hydroxylated PVC and polydimethyl siloxane.

5. The method of claim 2, wherein the polymer layer comprises from 60 to 80% plasticizer.

6. The method of claim 2, wherein the plasticizer is selected from the group consisting of trioctyl phosphate (TOP), nitrophenyloctyl ether (NPOE), bisethylhexylsebacate (BEHS), trimethyl trimellitate (TMTT), dioctyl adipate (DOA) and diisobutyl phthalate (DIBP).

7. The method of claim 2, wherein the polymer layer comprises from 0.1 to 10 wt. % of an organic salt.

8. The method of claim 2, wherein the polymer layer comprises a salt selected from the group consisting of quaternary ammonium tetrakis phenylborate, dodecyl sulfosuccinate, lauryl sulfate, alkyl ether phosphates, benzylkonium, cetylpyridinium dodecyl sulfosuccinate, lauryl sulfate, alkyl ether phosphates, tetramethylammonium, benzylkonium, cetylpyridinium, an iodide, a bromide, a perchlorate, a zwitterionic compound, cocamidopropyl hydroxysultaine and quaternary ammonium borate.

9. The method of claim 2, wherein the continuous polymer layer is substantially circular and has a diameter of from about 20 μ

m to about 2 mm.

10. The method of claim 9, wherein the device further comprises a boundary structure for controlling the spreading of a dispensed polymer layer precursor to a predetermined region of the device.

11. The method of claim 9, wherein the device further comprises a boundary structure for controlling the spreading of a dispensed liquid to a predetermined region of the device, wherein the boundary structure comprises a ring intersecting said first and second contact pads.

12. The method of claim 2, wherein the first and second pads are separated by a distance of from about 10 μ

m to about 2 mm.

13. The method of claim 12, wherein the continuous polymer layer is domed.

14. The method of claim 1, wherein the electrical property comprises current, resistance, impedance, conductivity, or a combination thereof.

15. The method of claim 14, further comprising measuring an initial current value associated with the continuous polymer layer when the device is manufactured and wherein the threshold level is at least five times lower than the initial current value.

16. The method of claim 14, further comprising measuring an initial impedance value associated with the continuous polymer layer when the device is manufactured, wherein the threshold level is at least five times greater than the initial impedance.

17. The method of claim 1, wherein the distance between the first and second electrical pads is from 10 μ

m to 2 mm.

18. The method of claim 1, wherein the potential comprises a sigmoidal potential cycle, a fixed applied potential, a sequence of fixed applied potential steps, or a combination thereof.

19. The method of claim 1, wherein the potential comprises a potential cycle that is applied at a predetermined frequency in the range of about 1 Hz to about 100 Hz.

20. The method of claim 1, further comprising inserting the device into an analyzer configured to determine whether the measured electrical property associated with the continuous polymer layer has exceeded the threshold level associated with the device usability.

21. The method of claim 1, where the device further comprises a sensor selected from the group consisting of a pH sensor, oxygen sensor, carbon dioxide sensor, hematocrit sensor, glucose sensor, lactate sensor, creatinine sensor, sodium sensor, potassium sensor, magnesium sensor, calcium sensor, chloride sensor, phosphate sensor, liver enzyme sensor, BNP sensor, troponin sensor, BUN sensor, CKMB sensor, NGAL sensor, TSH sensor, D-dimer sensor, PSA sensor, PTH sensor, cholesterol sensor, ALT sensor, AST sensor, prothrombin sensor, APTT sensor, ACT sensor, galectin sensor, and combinations thereof.

22. A device having a usability threshold, comprising

a first electrical pad, a second electrical pad, and a continuous polymer layer contacting at least a portion of the first and second electrical pads,

wherein the continuous polymer layer has an electrical property associated with the device usability threshold.

23. The device of claim 22, wherein the polymer layer comprises a polymer matrix, a plasticizer and an organic salt.

24. The device of claim 23, wherein the polymer layer comprises from 20 to 40 wt. % polymer matrix.

25. The device of claim 23, wherein the polymer matrix comprises a polymer selected from the group consisting of polyvinyl chloride, polyurethane, polyvinylacetate, carboxylated PVC, hydroxylated PVC and polydimethyl siloxane.

26. The device of claim 23, wherein the polymer layer comprises from 60 to 80% plasticizer.

27. The device of claim 23, wherein the plasticizer is selected from the group consisting of trioctyl phosphate (TOP), nitrophenyloctyl ether (NPOE), bisethylhexylsebacate (BEHS), trimethyl trimellitate (TMTT), dioctyl adipate (DOA) and diisobutyl phthalate (DIBP).

28. The device of claim 23, wherein the polymer layer comprises from 0.1 to 10 wt. % of an organic salt.

29. The device of claim 23, wherein the polymer layer comprises a salt selected from the group consisting of quaternary ammonium tetrakis phenylborate, dodecyl sulfosuccinate, lauryl sulfate, alkyl ether phosphates, benzylkonium, cetylpyridinium dodecyl sulfosuccinate, lauryl sulfate, alkyl ether phosphates, tetramethylammonium, benzylkonium, cetylpyridinium, an iodide, a bromide, a perchlorate, a zwitterionic compound, cocamidopropyl hydroxysultaine and quaternary ammonium borate.

30. The device of claim 23, wherein the continuous polymer layer is substantially circular and has a diameter of from about 20 μ

m to about 2 mm.

31. The device of claim 30, further comprising a boundary structure for controlling the spreading of a dispensed polymer layer precursor to a predetermined region of the device.

32. The device of claim 30, further comprising a boundary structure for controlling the spreading of a dispensed liquid to a predetermined region of the device, wherein the boundary structure comprises a ring intersecting said first and second contact pads.

33. The device of claim 23, wherein the first and second pads are separated by a distance of from about 10 μ

m to about 2 mm.

34. The device of claim 23, wherein the continuous polymer layer is domed.

35. The device of claim 22, wherein the distance between the first and second electrical pads is from 10 μ

m to 2 mm.

36. The device of claim 22, further comprising a sensor selected from the group consisting of a pH sensor, oxygen sensor, carbon dioxide sensor, hematocrit sensor, glucose sensor, lactate sensor, creatinine sensor, sodium sensor, potassium sensor, magnesium sensor, calcium sensor, chloride sensor, phosphate sensor, liver enzyme sensor, BNP sensor, troponin sensor, BUN sensor, CKMB sensor, NGAL sensor, TSH sensor, D-dimer sensor, PSA sensor, PTH sensor, cholesterol sensor, ALT sensor, AST sensor, prothrombin sensor, APTT sensor, ACT sensor, galectin sensor, and combinations thereof.

37. A method of making a device having a usability threshold, comprising the steps of:

providing a substantially planar surface comprising a first electrical pad and a second electrical pad;

dispensing a polymer layer precursor onto the surface, and

forming from the polymer layer precursor a continuous polymer layer contacting at least a portion of the first and second electrical pads,

wherein the continuous polymer layer has an electrical property associated with the device usability threshold.

38. The method of claim 37, wherein the polymer layer precursor comprises an aqueous solution comprising polymer particles dispersed in water.

39. The method of claim 37, wherein the polymer layer comprises a polymer matrix, a plasticizer and an organic salt.

40. The method of claim 37, wherein the device further comprises a boundary structure that controls the region of the device where the liquid is dispensed.

41. The method of claim 40, wherein the boundary structure comprises a ring intersecting the first and second electrical pads.

42. A method of determining a threshold level associated with analytical device usability, comprising the steps of:

providing a plurality of devices, each of said devices comprising a sensor;

a first electrical pad;

a second electrical pad; and

a continuous polymer layer contacting at least a portion of the first and second electrical pads, wherein said devices have been exposed to different environmental conditions;

measuring an electrical property of the continuous polymer layer for each of the devices;

measuring a sensor signal for a control fluid for each of the devices;

identifying a subset of said plurality of devices that provide a signal having a predetermined acceptable precision level for said control fluid; and

determining the threshold level that corresponds to the electrical property of the continuous polymer layer for the subset of said plurality of devices.

43. The method of claim 42, wherein the environmental conditions include variations in at least one of time, temperature, or humidity.

44. A device comprising a continuous polymer layer formed on a substantially planar surface wherein the surface comprises two adjacent electrical contact pads having a space therebetween, said polymer layer covering at least a portion of the two electrical contact pads and a portion of the space therebetween, wherein when a preselected potential or potential cycle is applied to the pads and the impedance or current associated with said polymer layer is measured, said measured value determines whether or how the device is used.

45. A device comprising a sensor and a continuous polymer layer formed on a substantially planar surface wherein the surface comprises two adjacent electrical contact pads and a space therebetween, wherein said polymer layer covers at least a portion of the two electrical contact pads and a portion of said space therebetween, wherein a preselected potential or potential cycle is applied to the pads and the impedance or current associated with said polymer layer is measured, said measured value is converted to a value indicative of the average shelf life time remaining for other devices from the same manufacturing lot.