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

• US 9,366,636 B2
• Filed: 02/04/2015
• Issued: 06/14/2016
• Est. Priority Date: 06/13/2005
• Status: Active Grant

• Current Assignee: Intuity Medical, Inc.
• Original Assignee: Intuity Medical, Inc.
• Inventors: Emery, Jeffrey L., Stivers, Carole R.
• Primary Examiner(s): Fritchman, Rebecca M
• Application Number:
  US14/614,177
• Publication Number:
  US 20150212006A1
• Time in Patent Office: 496 Days
• Field of Search: 600/583, 422/420
• US Class Current: 1/1
• 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 color change at 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 derived from the color change at the reaction spot indicative of one or more of;

(i) the volume of the sample applied to the assay pad; and

(ii) imperfections present in the reaction spot; and

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

2. The arrangement of claim 1, wherein the assay pad comprises only a single chemical reagent.

3. The arrangement of claim 1, wherein the detector array comprises a plurality of pixels, and wherein the at least one value derived from the color change at the reaction spot indicative of the volume of the sample applied to the assay pad is based on the number of pixels in the detector array that have detected the color change.

4. The arrangement of claim 1, wherein the at least one value derived from the color change at the reaction spot indicative of imperfections present in the reaction spot is based on deviations from an expected color or an expected rate of color change.

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

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

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

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

9. The arrangement of claim 1, further comprising at least one body fluid sampling catalyst device.

10. The arrangement of claim 9, wherein the at least one catalyst device comprises at least one of a vacuum pump, a vibration motor, and a heating element.

11. The arrangement of claim 9, wherein the at least one catalyst device is configured to be responsive to control signals, the control signals based on sample volume calculations.

12. The arrangement of claim 8, wherein at least a portion of the plurality of detector elements are not in optical registry with the reagent spot and are configured 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.

13. 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.

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

R_c=F_x×

R

where R_c is the corrected signal, F_x is the at least one value indicative of the volume of the sample, and where R is measured reflectance.

15. 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.

16. An analyte monitoring device comprising the arrangement of claim 1, 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.

17. The analyte monitoring device of claim 16, further comprising a band for attaching the device to the body of the user.

18. An integrated meter comprising:

at least one piercing element;

at least one actuation member; and

the arrangement of claim 1.