Automated system for continuously and automatically calibrating electrochemical sensors

• US 20030062262A1
• Filed: 08/22/2002
• Published: 04/03/2003
• Est. Priority Date: 08/22/2001
• Status: Active Grant

• Current Assignee: Instrumentation Lab Co (Instrumentation Lab)
• Original Assignee: Instrumentation Lab Co (Instrumentation Lab)
• Inventors: Fallon, Kevin, Mansouri, Sohrab, Eames, Patti
• Granted Patent: US 7,022,219 B2
• Time in Patent Office: Days
• US Class Current: 204/400
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1477 non-invasive
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: G01N 27/38 Cleaning of electrodes
• CPC Class Codes: G01N 33/492 Determining multiple analytes
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing

Abstract

An electrochemical sensor system that continuously monitors and calibrates the sensors included in the system. The invention also includes a method for determining failure patterns of a sensor and incorporating into an electrochemical sensor system the ability to recognize the failure pattern and initiate remedial action.

Claims

1. A method for automatic monitoring of an electrochemical sensor system comprising:

(i) providing an electrochemical sensor system comprising at least one electrochemical sensor;

(ii) analyzing an analyte comprising a known concentration in a first reference solution to determine a first measurement of said known concentration of said analyte in said first reference solution;

(iii) analyzing said analyte in said first reference solution to determine a second measurement of said known concentration of said analyte in said first reference solution;

(iv) comparing said known concentration, said first measurement of said known concentration and said second measurement of said known concentration of said analyte in said first reference solution; and

(v) automatically initiating corrective action if said first measurement of said analyte is substantially similar to said second measurement of said analyte and said first and said second measurements are substantially dissimilar to said known concentration of said analyte in said first reference solution.

2. The method of claim 1, wherein said corrective action comprises calibrating said electrochemical sensor according to said known concentration of said analyte of said reference solution.

3. The method of claim 1, wherein said corrective action comprises rinsing said electrochemical sensor.

4. The method of claim 1, wherein said electrochemical sensor system further comprises a sample flow channel disposed adjacent to said electrochemical sensor.

5. The method of claim 1 further comprising providing said first reference solution in a disposable cartridge.

6. The method of claim 5, wherein said sensor is provided in said cartridge.

7. The method of claim 1 further comprising determining a blood glucose level of a blood sample.

8. The method of claim 7 further comprising receiving the blood sample from a blood glucose test strip.

9. The method of claim 1 further comprising measuring blood urea nitrogen (BUN) of a blood sample.

10. A method for automatic monitoring of an electrochemical sensor system for measuring an analyte in a fluid sample comprising:

(i) providing an electrochemical sensor system comprising at least one electrochemical sensor;

(ii) analyzing an analyte comprising a known concentration in a first reference solution to determine a first measurement of said known concentration of said analyte;

(iii) analyzing said analyte in said first reference solution to determine a second measurement of said known concentration of said analyte;

(iv) comparing said known concentration, first measurement of said known concentration and second measurement of said known concentration; and

(v) measuring said analyte concentration in said fluid sample if said first measurement of said known concentration of said analyte in said first reference solution and said second measurement of said known concentration of said analyte in said first reference solution are sufficiently dissimilar and said second measurement of said known concentration of said first reference solution is sufficiently similar to said known concentration of said reference solution.

11. An electrochemical sensor system comprising:

(a) a first reference solution comprising a known concentration of at least one analyte;

(b) an electrochemical sensor analyzing said analyte to determine a first measurement and a second measurement of said known concentration of said analyte;

(c) a comparator comparing said known concentration, said first measurement of said known concentration, and said second measurement of said known concentration of said analyte; and

(d) a corrective action device initiating corrective action if said first measurement of said analyte in said first reference solution is substantially similar to said second measurement of said analyte in said first reference solution and said first and said second measurements are substantially dissimilar to said known concentration of said analyte in said first reference solution.

16. An electrochemical sensor system comprising:

(i) means for analyzing an analyte comprising a known concentration in a first reference solution to determine a first measurement of said known concentration of said analyte in said first reference solution;

(iii) means for analyzing said analyte in said first reference solution to determine a second measurement of said known concentration of said analyte in said first reference solution;

(iv) means for comparing said known concentration, said first measurement of said known concentration and said second measurement of said known concentration of said analyte in said first reference solution; and

(v) means for automatically initiating corrective action if said first measurement of said analyte is substantially similar to said second measurement of said analyte and said first and said second measurements are substantially dissimilar to said known concentration of said analyte in said first reference solution.

12. The electrochemical sensor system of claim 14 further comprising a cartridge for holding said first reference solution.

13. The electrochemical sensor system of claim 14 further comprising a microprocessor to perform at least one of measurement, calculation, storage, and control functions relating to at least one of said analyte and said measurements of said analyte.

14. The electrochemical sensor system of claim 16, wherein said microprocessor comprises said corrective action device.

15. The electrochemical sensor system of claim 14 further comprising a rinser to rinse said electrochemical sensor.