Method of and system for stabilization of sensors

• US 9,549,698 B2
• Filed: 01/11/2011
• Issued: 01/24/2017
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Shah, Rajiv, Reghabi, Bahar, Henke, James L., Morgan, Wayne A., Soundararajan, Gopikrishnan, Choy, David Y., Schultz, Peter, Hoss, Udo
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): TOTH, KAREN E
• Application Number:
  US13/004,646
• Publication Number:
  US 20110125446A1
• Time in Patent Office: 2,205 Days
• Field of Search: None
• US Class Current: 1/1
• 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 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: G01N 27/327 Biochemical electrodes , e.g. electrical or mechanical details for in vitro measurements
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771

Abstract

A blood glucose sensing system includes a sensor and a sensor electronics device. The sensor includes a plurality of electrodes. The sensor electronics device includes stabilization circuitry. The stabilization circuitry causes a first voltage to be applied to one of the electrodes for a first timeframe and causes a second voltage to be applied to one of the electrodes for a second timeframe. The stabilization circuitry repeats the application of the first voltage and the second voltage to continue the anodic-cathodic cycle. The sensor electronics device may include a power supply, a regulator, and a voltage application device, where the voltage application device receives a regulated voltage from the regulator, applies a first voltage to an electrode for the first timeframe, and applies a second voltage to an electrode for the second timeframe.

Claims

1. A method of stabilizing a glucose sensor having a plurality of electrodes for measuring a patient'"'"'s glucose level, the method comprising:

applying a first stabilization voltage to one of the plurality of electrodes to initiate an anodic cycle in the sensor, said first stabilization voltage being between 0.8 volts and 1.34 volts;

applying a second stabilization voltage to said one of the plurality of electrodes to initiate a cathodic cycle in the sensor, said second stabilization voltage being between 0.235 volts and 0.835 volts;

repeating, for one or more iterations, the application of the first stabilization voltage followed by the application of the second stabilization voltage until a measured electrical characteristic of the sensor meets a predetermined criterion which indicates sensor stabilization;

measuring the patient'"'"'s glucose level with the electrodes, and beginning to use said measured glucose levels of the patient'"'"'s glucose level after the sensor is stabilized.

2. The method of claim 1, wherein the first stabilization voltage has a negative value.

3. The method of claim 1, further including initiating a stabilization period when said first stabilization voltage is first applied, wherein the one or more iterations continue until said stabilization period has elapsed.

4. The method of claim 1, wherein the first stabilization voltage is a voltage waveform selected from the group consisting of a ramp waveform, a sinusoidal waveform, a stepped waveform, and a squarewave waveform.

5. The method of claim 4, wherein, in a first iteration, the first stabilization voltage waveform is a first type of waveform and, in a second iteration, the first stabilization voltage waveform is a second type of waveform.

6. The method of claim 1, wherein the second stabilization voltage is a second voltage waveform.

7. The method of claim 6, wherein the second stabilization voltage waveform is one of a ramp waveform, a sinusoid waveform, a stepped waveform, and a squarewave waveform.

8. The method of claim 1, wherein the first stabilization voltage is applied for a first timeframe and the second stabilization voltage is applied for a second timeframe, said first and second timeframes having different durations.

9. The method of claim 1, wherein the first stabilization voltage is applied for a first timeframe, and the duration of the first timeframe for a first iteration is different than the duration of the first timeframe for a subsequent iteration.

10. The method of claim 1, wherein said electrical characteristic is one of a current, a voltage, a resistance, and an impedance.

11. The method of claim 1 wherein said criterion is a lower threshold value.

12. The method of claim 1, wherein said criterion is an upper threshold value.

13. The method of claim 1, wherein said criterion is met if the electrical characteristic remains stable over a predefined timeframe.