Microprocessors, devices, and methods for use in monitoring of physiological analytes

• US 20050069925A1
• Filed: 07/30/2004
• Published: 03/31/2005
• Est. Priority Date: 08/15/2003
• Status: Abandoned Application

• Current Assignee: Animas Technologies LLC (Johnson & Johnson)
• Original Assignee: Animas Technologies LLC (Johnson & Johnson)
• Inventors: Tamada, Janet A., Tierney, Michael J., Lesho, Matthew J., Ford, Russell
• Application Number:
  US10/903,672
• Publication Number:
  US 20050069925A1
• Time in Patent Office: Days
• US Class Current: 435/6
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/4266 sweat secretion
• CPC Class Codes: A61B 5/4283 gastrointestinal secretions, e.g. bile production
• CPC Class Codes: A61B 5/4881 Determining interstitial fluid distribution or content within body tissue measuring analytes in interstitial fluid in-vivo A61B5/1451
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: G16H 40/63 for local operation

Abstract

Described herein are microprocessors, devices, and methods useful for sweat and/or temperature detection that correlate more closely with changes in amperometric or charge signals related to analyte amount or concentration. The present invention provides methods for the establishment of more accurate sweat and/or temperature thresholds and new methods of compensation, such as correcting for the effects of sweat and rapidly changing temperature on measured analyte values. The present invention reduces the number of skipped or unuseable readings provided by analyte monitoring devices during periods of sweating or changing temperatures. Further, the present invention provides methods for improving the accuracy of reported readings of analyte amount or concentration. In one aspect, the present invention provides passive collection reservoir/sensing devices used in combination with active collection reservoir/sensing devices for detection of sweat and/or temperature related parameters.

Claims

1. One or more microprocessors comprising programming to control providing a first signal related to analyte amount or concentration in a subject from a first sample comprising an analyte, wherein said first sample is obtained by use of a method that enhances transport of the analyte across a skin or mucosal surface of said subject;

providing a second signal related to analyte amount or concentration from a second sample comprising said analyte, wherein said second sample is obtained substantially without use of a method that enhances transport of the analyte across the skin or mucosal surface of the subject, and said first signal and said second signal are obtained for substantially a same time period; and

qualifying said first signal by a method selected from the group consisting of (i) screening said first signal based on said second signal;

(ii) applying a correction algorithm to said first signal, wherein said first signal is adjusted by use of said second signal; and

(iii) combinations thereof.

2. The one or more microprocessors of claim 1, wherein said qualifying comprises screening said first signal based on said second signal, and said screening comprises (a) comparing said second signal to a predetermined high and/or low threshold value, (b) skipping an analyte measurement value associated with said first signal if said second signal is above said high threshold value or below said low threshold value, and (c) accepting said first signal for determination of an associated analyte measurement value if said second signal is between said high threshold value and said low threshold value.

3. The one or more microprocessors of claim 2, wherein said qualifying further comprises obtaining a skin conductance value for substantially the same time period as said first and second signals, comparing said skin conductance value to a predetermined skin conductance threshold value, and if said skin conductance value equals or exceeds said skin conductance threshold value, then said first signal is screened based on said second signal, wherein said screening comprises (a) comparing said second signal to a predetermined high and/or low threshold value, (b) skipping an analyte measurement value associated with said first signal if said second signal is above said high threshold value or below said low threshold value, and (c) accepting said first signal for determination of an associated analyte measurement value if said second signal is between said high threshold value and said low threshold value.

4. The one or more microprocessors of claim 2, wherein said qualifying further comprises obtaining a temperature value for substantially the same time period as said first and second signals, comparing said temperature value to a predetermined high and/or low temperature threshold value, and if said temperature value is above said high temperature threshold value or below said low temperature threshold value, then said first signal is screened based on said second signal, wherein said screening comprises (a) comparing said second signal to a predetermined high and/or low threshold value, (b) skipping an analyte measurement value associated with said first signal if said second signal is above said high threshold value or below said low threshold value, and (c) accepting said first signal for determination of an associated analyte measurement value if said second signal is between said high threshold value and said low threshold value.

5. The one or more microprocessors of claim 2 further comprising after accepting said first signal for determination of an associated analyte measurement value a correction algorithm is applied to said first signal, wherein said first signal is adjusted by use of said second signal.

6. The one or more microprocessors of claim 1, wherein said qualifying comprises applying a correction algorithm to said first signal, said correction algorithm comprises correcting said first signal by subtracting at least a portion of said second signal.

7. The one or more microprocessors of claim 6, wherein said first and second signal are amperometric or coulometric, and said correction algorithm comprises Q=Q_a−

kQ_p, where Q is a signal input for determination of an analyte measurement value, Q_a is said first signal, k is a proportionality factor that is a value between 0 and 1, and Q_p is said second signal.

8. The one or more microprocessors of claim 1, wherein said qualifying comprises applying a correction algorithm to said first signal, said correction algorithm comprises correcting said first signal by subtracting at least a portion of said second signal, further taking into account said second signal at a calibration time point.

9. The one or more microprocessors of claim 8, wherein said first and second signal are amperometric or coulometric, and said correction algorithm comprises Q=Q_a−

k(Q_p−

Q_pcal) where Q is a signal input for determination of an analyte measurement value, Q_a is said first signal, k is a proportionality factor that is a value between 0 and 1, Q_p is said second signal, and Q_pcal is said second signal at the calibration time point.

10. The one or more microprocessors of claim 1, wherein said method that enhances transport of the analyte across a skin or mucosal surface of said subject is selected from the group consisting of iontophoresis, sonophoresis, suction, electroporation, thermal poration, use of microporation, use of microneedles, use of microfine lances, skin permeabilization, chemical permeation enhancers, use of laser devices, and combinations thereof.

11. The one or more microprocessors of claim 10, wherein said method that enhances transport of the analyte across a skin or mucosal surface of said subject is iontophoresis, sonophoresis, or laser poration.

12. The one or more microprocessors of claim 1, wherein said signal is an electrochemical signal.

13. The one or more microprocessors of claim 12, wherein said electrochemical signal is an amperometric or coulometric signal.

14. The one or more microprocessors of claim 13, wherein said analyte is glucose and said electrochemical signal is obtained by contacting a sensing electrode and glucose oxidase with said samples.

15. The one or more microprocessors of claim 1, wherein said analyte is glucose.

16. The one or more microprocessors of claim 1, further comprising programming to control

operating a first sensing device that provides said first signal;

operating a second sensing device that provides said second signal.

17. The one or more microprocessors of claim 16, further comprising programming to control

operating a first sampling device that provides said first sample.

18. The one or more microprocessors of claim 17, wherein said sampling device employs iontophoresis to provide said first sample.

19. An analyte monitoring device comprising said one or more microprocessors of claim 1.

20. An analyte monitoring device comprising

said one or more microprocessors of claim 1, and

first and second electrochemical sensing devices.

21. An analyte monitoring device comprising

said one or more microprocessors of claim 18,

first and second electrochemical sensing devices, and

an iontophoretic sampling device.

22. An analyte monitoring device comprising,

(A) One or more collection reservoirs adapted for contact with a skin or mucosal surface of a subject, wherein (i) movement of said analyte into said collection reservoirs is enhanced by a transdermal or transmucosal sampling method, and (ii) during use of said device at least one collection device is placed in operative contact with an analyte sensing device;

and

(B) One or more collection reservoirs adapted for contact with a skin or mucosal surface of a subject, wherein (i) movement of said analyte into said collection reservoirs not enhanced by said transdermal or transmucosal sampling method, and (ii) during use of said device at least one collection device is placed in operative contact with an analyte sensing device.

23. The analyte monitoring device of claim 22, wherein during use of said device at least one collection reservoir of (B) is in contact with a thermistor.

24. The analyte monitoring device of claim 22, wherein the physical characteristics of at least one collection reservoir of (A) are substantially the same as the physical characteristics of at least one collection reservoir of (B).

25. The analyte monitoring device of claim 24, wherein the at least one collection reservoir of (A) comprises a hydrogel.

26. The analyte monitoring device of claim 22, wherein said analyte sensing device is a device that detects analyte electrochemically.

27. The analyte monitoring device of claim 26, wherein said analyte sensing device comprises a sensing electrode.

28. The analyte monitoring device of claim 27, wherein the physical characteristics of the sensing electrode in contact with at least one collection reservoir of (A) has substantially the same physical characteristics of the sensing electrode in contact with at least one collection reservoir of (B).

29. The analyte monitoring device of claim 27, wherein said analyte sensing device further comprises an enzyme to facilitate electrochemical detection of the analyte.

30. The analyte monitoring device of claim 29, wherein said analyte is glucose and said enzyme comprises glucose oxidase.

31. The analyte monitoring device of claim 27, further comprising iontophoretic electrodes in contact with said one or more collection reservoirs of (A).

32. The analyte monitoring device of claim 22, wherein a collection reservoir of (B) comprises first and second surfaces, said first surface is in contact with a sensing device and said second surface is in contact with a membrane substantially impermeable to analyte, and said membrane is adapted for contact with said skin or mucosal surface.

33. A method of qualifying a signal related to an analyte amount or concentration in samples obtained by use of a method that enhances transport of the analyte across a skin or mucosal surface of a subject, said method comprising

providing a first signal related to analyte amount or concentration in the subject from a first sample comprising said analyte, wherein said first sample is obtained by use of a method that enhances transport of the analyte across a skin or mucosal surface of said subject;

providing a second signal related to analyte amount or concentration from a second sample comprising said analyte, wherein said second sample is obtained substantially without use of a method that enhances transport of the analyte across the skin or mucosal surface of the subject, and said first signal and said second signal are obtained for substantially a same time period;

qualifying said first signal by a method selected from the group consisting of (i) screening said first signal based on said second signal;

(ii) applying a correction algorithm to said first signal, wherein said first signal is adjusted by use of said second signal; and

(iii) combinations thereof.

34. The method of claim 33, wherein said qualifying comprises screening said first signal based on said second signal, and said screening comprises (a) comparing said second signal to a predetermined high and/or low threshold value, (b) skipping an analyte measurement value associated with said first signal if said second signal is above said high threshold value or below said low threshold value, and (c) accepting said first signal for determination of an associated analyte measurement value if said second signal is between said high threshold value and said low threshold value.

35. The method of claim 34, wherein said qualifying further comprises obtaining a skin conductance value for substantially the same time period as said first and second signals, comparing said skin conductance value to a predetermined skin conductance threshold value, and if said skin conductance value equals or exceeds said skin conductance threshold value, then said first signal is screened based on said second signal, wherein said screening comprises (a) comparing said second signal to a predetermined high and/or low threshold value, (b) skipping an analyte measurement value associated with said first signal if said second signal is above said high threshold value or below said low threshold value, and (c) accepting said first signal for determination of an associated analyte measurement value if said second signal is between said high threshold value and said low threshold value.

36. The method of claim 34, wherein said qualifying further comprises obtaining a temperature value for substantially the same time period as said first and second signals, comparing said temperature value to a predetermined high and/or low temperature threshold value, and if said temperature value is above said high temperature threshold value or below said low temperature threshold value, then said first signal is screened based on said second signal, wherein said screening comprises (a) comparing said second signal to a predetermined high and/or low threshold value, (b) skipping an analyte measurement value associated with said first signal if said second signal is above said high threshold value or below said low threshold value, and (c) accepting said first signal for determination of an associated analyte measurement value if said second signal is between said high threshold value and said low threshold value.

37. The method of claim 35, further comprising after accepting said first signal for determination of an associated analyte measurement value a correction algorithm to said first signal, wherein said first signal is adjusted by use of said second signal.

38. The method of claim 33, wherein said qualifying comprises applying a correction algorithm to said first signal, said correction algorithm comprises correcting said first signal by subtracting at least a portion of said second signal.

39. The method of claim 38, wherein said first and second signal are amperometric or coulometric, and said correction algorithm comprises Q=Q_a−

kQ_p, where Q is a signal input for determination of an analyte measurement value, Q_a is said first signal, k is a proportionality factor that is a value between 0 and 1, and Q_p is said second signal.

40. The method of claim 33, wherein said qualifying comprises applying a correction algorithm to said first signal, said correction algorithm comprises correcting said first signal by subtracting at least a portion of said second signal, further taking into account said second signal at a calibration time point.

41. The method of claim 40, wherein said first and second signal are amperometric or coulometric, and said correction algorithm comprises Q=Q_a−

k(Q_p−

Q_pcal) where Q is a signal input for determination of an analyte measurement value, Q_a is said first signal, k is a proportionality factor that is a value between 0 and 1, Q_p is said second signal, and Q_pcal is said second signal at the calibration time point.

42. The method of claim 33, wherein said method that enhances transport of the analyte across a skin or mucosal surface of said subject is selected from the group consisting of iontophoresis, sonophoresis, suction, electroporation, thermal poration, use of microporation, use of microneedles, use of microfine lances, skin permeabilization, chemical permeation enhancers, use of laser devices, and combinations thereof.

43. The method of claim 42, wherein said method that enhances transport of the analyte across a skin or mucosal surface of said subject is iontophoresis, sonophoresis, or laser poration.

44. The method of claim 33, wherein said signal is an electrochemical signal.

45. The method of claim 44, wherein said electrochemical signal is an amperometric or coulometric signal.

46. The method of claim 45, wherein said analyte is glucose and said electrochemical signal is obtained by contacting a sensing electrode and glucose oxidase with said samples.

47. The method of claim 33, wherein said subject is a human.

48. The method of claim 33, wherein said analyte is glucose.