Devices and methods for testing analytes

• US 10,605,758 B2
• Filed: 05/10/2016
• Issued: 03/31/2020
• Est. Priority Date: 05/07/2010
• Status: Active Grant

• Current Assignee: PA Knowledge Limited
• Original Assignee: PA Knowledge Limited
• Inventors: Noble, Michael, Nelson, Craig, Humphries, Mark, Lloyd, Carys, Edington, David, Rippeth, John
• Primary Examiner(s): Kaur, Gurpreet
• Assistant Examiner(s): Rosenwald, Steven E
• Application Number:
  US15/151,004
• Publication Number:
  US 20160252477A1
• Time in Patent Office: 1,421 Days
• Field of Search: None
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: C12Q 1/54 involving glucose or galactose
• CPC Class Codes: G01N 2496/00 Reference solutions for assays of biological material
• CPC Class Codes: G01N 27/3271 Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood amperometry per se G01N27/49; aspects concerning the enzyme reagent C12Q1/001
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• 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: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80
• CPC Class Codes: G01N 33/4915 using flow cells flow cytometry G01N15/14

Abstract

A method and device are provided for measuring a level of a clinically relevant analyte (such as glucose) in a fluid (such as blood). The device includes a flow path for conducting said fluid through the device; a detection chamber arranged on said flow path; and detector means arranged to detect analyte levels in the fluid in said chamber, wherein: said detection chamber contains a predetermined amount of an analyte such that that analyte mixes with fluid in the detection chamber to form, at the detector means, a calibration sample of the fluid at a time after the arrival of the fluid in said detection chamber, and said detector means is arranged to detect a first analyte level of an unadulterated sample of the fluid at a first time which is before the formation of said calibration sample and to detect a second analyte level of said calibration sample at a second time which is after the formation of said calibration sample.

Claims

1. A method for testing, in a portable device, a level of a clinically relevant analyte in a fluid, the method including the steps of:

guiding an unadulterated sample of the fluid to a detection chamber containing an electrode at a location in the detection chamber and a known amount of an analyte which is spatially removed from the electrode;

measuring at said location, using the electrode, the clinically relevant analyte level in said unadulterated sample of the fluid at a first predetermined time after the arrival of the fluid in said detection chamber;

measuring at said location, using the same electrode, an analyte level in a calibration sample of the fluid formed by mixing said unadulterated sample of the fluid with said known amount of said analyte at a second predetermined time after the arrival of the fluid in said detection chamber, the second predetermined time being later than said first predetermined time; and

adjusting the clinically relevant analyte level measured in said unadulterated sample using the analyte level measured in said calibration sample.

2. A method according to claim 1 wherein said analyte in said known amount of analyte is the same as said clinically relevant analyte.

3. A method according to claim 1 further including the step of generating the clinically relevant analyte level reading from said adjusted clinically relevant analyte level, wherein said step of adjusting is carried out on an unprocessed measurement of the clinically relevant analyte level in the unadulterated sample.

4. A method according to claim 1 further including the step of generating the clinically relevant analyte level reading from the measurement of the clinically relevant analyte level in the unadulterated sample, wherein said step of adjusting is carried out on the clinically relevant analyte level reading.

5. A method according to claim 1 wherein the step of adjusting is performed by comparison with an expected relationship.

6. A method according to claim 1 further including the step of measuring at said location, using the electrode, the analyte level in one or more further calibration samples of said fluid at further predetermined times after the arrival of the fluid in said detection chamber, wherein the further times are later than said second predetermined time, and wherein the step of adjusting uses all measured analyte levels.

7. A method according to claim 1 further including the step of releasing said predetermined amount of analyte into the detection chamber for mixing with said fluid in said chamber.

8. A method according to claim 1 wherein the sample of fluid which is guided to the detection chamber contains a known amount of said clinically relevant analyte, and further including the step of determining the condition of the portable device based on said measurements.

9. A method according to claim 1 further including a step of storing non-analyte specific information from the clinically relevant and calibration sample analyte levels measured.

10. A method according to claim 9 further including the steps of:

storing a record of said non-analyte specific information;

updating said record after subsequent measurements; and

determining a deviation from said record in a subsequent measurement.

11. A method according to claim 10 further including the step of, if said deviation is greater than a predetermined amount, alerting the user.

12. A method according to claim 1 further including the steps of:

recording said measured clinically relevant and calibration sample analyte levels for a predetermined length of time;

analysing the shape of the measured clinically relevant and calibration sample analyte levels over said predetermined length of time; and

selecting, based on said analysis, a correction algorithm from a plurality of such algorithms, to be used in said step of adjusting.

13. A method according to claim 12 wherein the step of analysing the shape of the measured clinically relevant and calibration sample analyte levels analyses one or more of the following features of the measured clinically relevant and calibration sample analyte levels:

absolute value of the measured parameter, peak height, time to peak height, and maximum gradient of transients for different error sources.