System and Method for Determining the Point of Hydration and Proper Time to Apply Potential to a Glucose Sensor

• US 20080156661A1
• Filed: 12/28/2007
• Published: 07/03/2008
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Vejella, Ratnakar, Shah, Rajiv, Soundararajan, Gopikrishnan, Choy, David Y., Cooper, Kenneth W.
• Granted Patent: US 8,114,269 B2
• Time in Patent Office: Days
• US Class Current: 205/775
• CPC Class Codes: A61B 17/3468 for implanting or removing devices, e.g. prostheses, implants, seeds, wires devices for implanting seeds A61M37/0069
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• 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

Abstract

According to an embodiment of the invention, a method of determining hydration of a sensor having a plurality of electrodes is disclosed. In particular embodiments, the method couples a sensor electronics device to the sensor and measures the open circuit potential between at least two of the plurality of electrodes. Then, the open circuit potential measurement is compared to a predetermined value. In some embodiments, the plurality of electrodes includes a working electrode, a reference electrode, and a counter electrode. In still further embodiments, the open circuit potential between the working electrode and the reference electrode is measured. In other embodiments, the open circuit potential between the working electrode and the counter electrode is measured. In still other embodiments, the open circuit potential between the counter electrode and the reference electrode is measured.

Claims

1. A method of determining hydration of a sensor having a plurality of electrodes, the method comprising the steps of:

coupling a sensor electronics device to the sensor;

measuring the open circuit potential between at least two of the plurality of electrodes; and

comparing the open circuit potential measurement to a predetermined value.

2. The method of claim 1, wherein the plurality of electrodes includes a working electrode, a reference electrode, and a counter electrode.

3. The method of claim 2, wherein the open circuit potential between the working electrode and the reference electrode is measured.

4. The method of claim 2, wherein the open circuit potential between the working electrode and the counter electrode is measured.

5. The method of claim 2, wherein the open circuit potential between the counter electrode and the reference electrode is measured.

6. The method of claim 2, wherein the open circuit potential between the working electrode and the reference electrode is measured, and wherein the open circuit potential between the working electrode and the counter electrode is measured.

7. The method of claim 2, wherein the open circuit potential between the working electrode and the reference electrode is measured, and wherein the open circuit potential between the counter electrode and the reference electrode is measured.

8. The method of claim 2, wherein the open circuit potential between the working electrode and the counter electrode is measured and wherein the open circuit potential between the counter electrode and the reference electrode is measured.

9. The method of claim 2, wherein the open circuit potential between the working electrode and the reference electrode is measured, and wherein the open circuit potential between the working electrode and the counter electrode is measured, and wherein the open circuit potential between the counter electrode and the reference electrode is measured.

10. The method of claim 1 further including the steps of:

calculating the rate of change of the open circuit potential measurement over a specified period of time, and

comparing the rate of change value to a predetermined value.

11. A system for determining the point of hydration of a sensor, the system comprising:

a sensor, the sensor including a plurality of electrodes; and

a sensor electronics device, the sensor electronics device including a hydration detection circuit,

wherein the hydration detection circuit measures the open circuit potential between at least two of the plurality of electrodes to determine the point of hydration of the sensor.

12. The system of claim 11, wherein the plurality of electrodes includes a working electrode, a reference electrode, and a counter electrode.

13. The system of claim 12, wherein the open circuit potential between the working electrode and the reference electrode is measured.

14. The system of claim 12, wherein the open circuit potential between the working electrode and the counter electrode is measured.

15. The system of claim 12, wherein the open circuit potential between the counter electrode and the reference electrode is measured.

16. The system of claim 12, wherein the open circuit potential between the working electrode and the reference electrode is measured, and wherein the open circuit potential between the working electrode and the counter electrode is measured.

17. The system of claim 12, wherein the open circuit potential between the working electrode and the reference electrode is measured, and wherein the open circuit potential between the counter electrode and the reference electrode is measured.

18. The system of claim 12, wherein the open circuit potential between the working electrode and the counter electrode is measured and wherein the open circuit potential between the counter electrode and the reference electrode is measured.

19. The system of claim 12, wherein the open circuit potential between the working electrode and the reference electrode is measured, and wherein the open circuit potential between the working electrode and the counter electrode is measured, and wherein the open circuit potential between the counter electrode and the reference electrode is measured.

20. The system of claim 11, wherein the hydration detection circuit also calculates a rate of change of the open circuit potential measurements over a specified period of time to determine the point of hydration of the sensor.