Analyte detection devices and methods with hematocrit/volume correction and feedback control

• US 20060281187A1
• Filed: 09/30/2005
• Published: 12/14/2006
• Est. Priority Date: 06/13/2005
• Status: Abandoned Application

• Current Assignee: Intuity Medical, Inc.
• Original Assignee: Rosedale Medical Inc. (Intuity Medical, Inc.)
• Inventors: Stivers, Carole R., Emery, Jeffrey L.
• Application Number:
  US11/239,122
• Publication Number:
  US 20060281187A1
• Time in Patent Office: Days
• US Class Current: 436/169
• CPC Class Codes: A61B 2562/0295 Strip shaped analyte sensors for apparatus classified in A61B5/145 or A61B5/157 disposable multilayered or laminated electrodes G01N27/307; details of handling chemical test elements G01N33/4875
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/150358 Strips for collecting blood, e.g. absorbent optical reagent test strips G01N21/8483; chemical reagent test strips G01N33/4875, G01N33/52
• CPC Class Codes: A61B 5/155 Devices specially adapted for continuous or multiple sampling, e.g. at predetermined intervals devices loaded with multiple lancets simultaneously A61B5/15146
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood
• CPC Class Codes: A61B 5/6802 Sensor mounted on worn items
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: G01N 2021/752 Devices comprising reaction zones
• CPC Class Codes: G01N 21/78 producing a change of colour
• CPC Class Codes: G01N 33/523 the element being adapted for a specific analyte
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose
• CPC Class Codes: Y10S 435/895 Streptomyces filipinensis

Abstract

Disclosed are devices, arrangements and methods for quantifying the concentration of an analyte present in bodily fluid, including: an assay pad having at least one chemical reagent capable of producing a detectable signal in the form of a reaction spot upon reaction with the analyte; a light source; a detector array; a processor; and a memory in communication with the processor, the memory comprising: (a) at least one value indicative of one or more of: (i) the level of hematocrit contained in the sample; (ii) the volume of the sample applied to the assay pad; or (iii) imperfections present in the reaction spot; and (b) at least one algorithm for calculating the concentration of the analyte contained in the sample.

Claims

1. An arrangement for measuring the concentration of an analyte contained in a sample of body fluid, the arrangement comprising:

an assay pad comprising at least one chemical reagent capable of producing a detectable signal in the form of a reaction spot formed upon reaction with the analyte;

a light source;

a detector array;

a processor; and

a memory in communication with the processor, the memory comprising;

(a) at least one value indicative of one or more of;

(i) the level of hematocrit contained in the sample;

(ii) the volume of the sample applied to the assay pad;

or

(iii) imperfections present in the reaction spot; and

(b) at least one algorithm for calculating the concentration of the analyte contained in the sample.

2. The arrangement of claim 1, wherein the analyte comprises glucose and the body fluid comprises blood.

3. The arrangement of claim 1, wherein the detector array is a linear array.

4. The arrangement of claim 1, wherein the detector array comprises at least one of a linear array, a polar array, and an area array.

5. The arrangement of claim 1, wherein the detector array comprises a plurality of detector elements, the detector elements comprising CMOS, CCD, photodiode, infrared, fluorescent, ultraviolet or electrochemical elements.

6. The arrangement of claim 1, further comprising at least one catalyst device.

8. The arrangement of claim 1, wherein the at least once catalyst device is constructed and arranged to be responsive to control signals, the control signals based on sample volume calculations.

9. The arrangement of claim 5, wherein at least a portion of the plurality of detector elements are not in optical registry with the reagent spot and are configured and arranged to analyze one or more of a control solution having a known concentration of analyte introduced onto an area of the assay pad that is different from the area of the reagent spot, a standard color producing a known signal, and calibration information specific to the lot of the assay pad.

10. The arrangement of claim 1, wherein the memory comprises at least one look-up table, and the at least one value is stored in the at least one look-up table.

11. The arrangement of claim 1, wherein the memory comprises a formula for deriving a corrected signal, the formula comprising:

12. The arrangement of claim 1, further comprising a needle having a first end configured to pierce the skin, and a second end in fluid communication with the assay pad.

13. An analyte monitoring device comprising the arrangement of claim 1.

14. The analyte monitoring device of claim 13, wherein the arrangement comprises a plurality of assay pads and a plurality of needles, thereby enabling the performance of a plurality of analyte concentration measurements.

15. The analyte monitoring device of claim 13, further comprising a band for attaching the device to the body of the user.

35. An integrated meter comprising:

at least one piercing element;

at least one actuation member; and

the arrangement of claim 1.

7. The arrangement of claim δ

, wherein the at least one catalyst device comprises at least one of a vacuum pump, a vibration motor and a heating element.

16. A method of measuring the content of analyte contained in a sample of body fluid, the method comprising:

providing an assay pad comprising at least one chemical reagent;

introducing a sample onto the assay pad;

producing a detectable signal in the form of a reaction spot formed upon reaction of the at least one chemical reagent with the analyte;

generating a signal based on light reflected off the assay pad;

calculating at least one value indicative to one or more of;

(i) the level of hematocrit contained in the sample;

(ii) the volume of the sample applied to the assay pad;

or

(iii) imperfections present in the reaction spot; and

calculating the concentration of analyte contained in the sample by factoring in the at least one value.

17. The method of claim 16, wherein the analyte comprises glucose and the body fluid comprises blood.

18. The method of claim 16, wherein the step of generating a signal based on light reflected off the assay pad comprises providing a detector array in optical registry with at least the reaction spot on the assay pad.

19. The method of claim 18, wherein the detector array comprises at least one of a linear array, a polar array, and an area array.

20. The method of claim 19, wherein the detector array comprises a plurality of detector elements, the detector elements comprising CMOS, CCD, photodiode, infrared, fluorescent, ultraviolet or electrochemical elements.

21. The method of claim 16, further comprising applying at least one catalyst to the surface of the skin of the user to facilitate sample acquisition.

22. The method of claim 21, wherein the at least one catalyst comprises at least one of a vacuum pressure, positive pressure, vibration, and heat.

23. The method of claim 21, wherein the step of applying at least once catalyst comprises controlling application of the catalyst with a control signal based on sample volume calculations.

24. The method of claim 20, further comprising using at least a portion of the plurality of detector elements not in optical registry with the reagent spot to analyze one or more of a control solution having a known concentration of analyte introduced onto an area of the assay pad that is different from the area of the reagent spot, reading a standard color producing a known signal, and reading calibration information specific to the lot of the assay pad.

25. The method of claim 16, wherein the step of calculating comprises acquiring the at least one value from at least one look-up table.

26. The method of claim 16, wherein the step of calculating the concentration of analyte comprises deriving a corrected signal from the formula comprising:

27. The method of claim 16, further comprising piercing the skin of the user with a first end of a needle, and transporting a sample of blood through a second end of the needle to the assay pad.

28. An arrangement for measuring the concentration of an analyte contained in a sample of body fluid, the arrangement comprising:

an assay pad comprising at least one chemical reagent capable of producing a detectable signal in the form of a reaction spot formed upon reaction with the analyte;

a light source;

a detector array;

a processor;

a memory in communication with the processor; and

at least one catalyst device constructed and arranged to be responsive to control signals.

29. The arrangement of claim 28, wherein the detector array comprises a linear array of detector elements, the detector elements comprising CMOS, CCD, photodiode, infrared, fluorescent, ultraviolet or electrochemical elements.

30. The arrangement of claim 28, wherein the at least one catalyst device comprises at least one of a vacuum pump, a vibration motor and a heating element.

31. The arrangement of claim 28, wherein the at least one catalyst device is constructed and arranged to be responsive to control signals derived from a signal based on light reflected off the assay pad and detected by the detector array.

32. The arrangement of claim 28, wherein a lease one catalyst device is constructed and arranged to be responsive to control signals derived from a signal based on imaging of a surface on the skin of the user.

33. The arrangement of claim 28, wherein the detector array, processor and memory are constructed and arranged to predict sample volume be delivered to the assay pad.

34. The arrangement of claim 33, wherein the sample volume to be delivered to the assay pad is predicted based at least in part on a signal generated by light reflected off the assay pad and detected by the detector array.

36. An integrated meter comprising:

at least one piercing element;

at least one actuation member; and

the arrangement of claim 28.