Nonlinear mapping technique for a physiological characteristic sensor

• US 10,001,450 B2
• Filed: 04/18/2014
• Issued: 06/19/2018
• Est. Priority Date: 04/18/2014
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Grosman, Benyamin, Keenan, Desmond Barry, Mastrototaro, John J., Shah, Rajiv, Varsavsky, Andrea, Yang, Ning
• Primary Examiner(s): Warden, Jill A
• Assistant Examiner(s): Fisher, Brittany I
• Application Number:
  US14/256,229
• Publication Number:
  US 20150300969A1
• Time in Patent Office: 1,523 Days
• Field of Search: None
• CPC Class Codes: G01N 27/026 Dielectric impedance spectroscopy electrochemical impedance spectroscopy for measuring corrosion G01N17/02

Abstract

A method of measuring blood glucose of a patient is presented here. In accordance with certain embodiments, the method applies a constant voltage potential to a glucose sensor and obtains a constant potential sensor current from the glucose sensor, wherein the constant potential sensor current is generated in response to applying the constant voltage potential to the glucose sensor. The method continues by performing an electrochemical impedance spectroscopy (EIS) procedure for the glucose sensor to obtain EIS output measurements. The method also performs a nonlinear mapping operation on the constant potential sensor current and the EIS output measurements to generate a blood glucose value.

Claims

1. A method of measuring blood glucose of a patient, the method comprising:

applying a constant voltage potential to a glucose sensor;

obtaining a constant potential sensor current from the glucose sensor, wherein the constant potential sensor current is generated in response to applying the constant voltage potential to the glucose sensor;

performing an electrochemical impedance spectroscopy (EIS) procedure for the glucose sensor to obtain EIS output measurements; and

performing a nonlinear mapping operation on the constant potential sensor current and the EIS output measurements to generate a blood glucose value.

2. The method of claim 1, wherein the nonlinear mapping operation generates the blood glucose value in the absence of any calibration factor for the glucose sensor.

3. The method of claim 1, wherein applying the constant voltage potential and performing the EIS procedure occur at different times.

4. The method of claim 1, wherein performing the EIS procedure comprises:

applying an alternating current (AC) voltage signal to the glucose sensor.

5. The method of claim 1, wherein the EIS procedure is performed for a plurality of frequencies.

6. The method of claim 1, further comprising:

obtaining temperature measurement data, wherein the nonlinear mapping operation is performed on the constant potential sensor current, the EIS output measurements, and the temperature measurement data to generate the blood glucose value.

7. The method of claim 1, wherein the nonlinear mapping operation is associated with a sensor characterization model for the glucose sensor.

8. The method of claim 1, wherein the nonlinear mapping operation comprises:

combining the constant potential sensor current and at least some of the EIS output measurements.

9. A sensor system comprising:

A sensor electrode; and

Sensor electronics coupled to the sensor electrode, the sensor electronics including one or more processors having executable instructions stored thereon, the executable instructions executed by the processor to;

Apply a constant voltage potential to the sensor electrode;

Obtain a constant potential sensor current from the sensor electrode, wherein the constant potential sensor current is generated in response to applying the constant voltage potential to the sensor electrode;

Perform an electrochemical impedance spectroscopy (EIS) procedure for the sensor electrode to obtain EIS output measurements; and

Perform a nonlinear mapping operation on the constant potential sensor current and the EIS output measurements to generate a sensor output value.

10. The sensor system of claim 9, wherein:

the sensor electrode comprises a glucose sensor electrode; and

the sensor output value comprises a blood glucose value.

11. The sensor system of claim 9, wherein applying the constant voltage potential and performing the EIS procedure occur concurrently.

12. The sensor system of claim 9, wherein the sensor electronics obtains temperature measurement data, wherein the nonlinear mapping operation is performed on the constant potential sensor current, the EIS output measurements, and the temperature measurement data to generate the blood glucose value.

13. The sensor system of claim 9, wherein the nonlinear mapping operation is associated with a sensor characterization model for the glucose sensor.

14. The sensor system of claim 9, wherein the nonlinear mapping operation comprises:

combining the constant potential sensor current and at least some of the EIS output measurements.

15. A sensor system comprising a sensor electrode, one or more processors, and a processor-readable storage medium having executable instructions stored thereon, wherein the executable instructions implement a method comprising:

Obtaining a constant potential sensor current from a glucose sensor, wherein the constant potential current is obtained in response to application of a constant voltage potential to the glucose sensor;

Obtaining electrochemical impedance spectroscopy (EIS) output measurement from the glucose sensor, wherein the EIS output measurements are obtained in response to application of alternating current (AC) voltage signals to the glucose sensor; and

Performing a nonlinear mapping operation on the constant potential sensor current and the EIS output measurement to generate a blood glucose value.

16. The sensor system of claim 15, wherein the nonlinear mapping operation generates the blood glucose value in the absence of any calibration factor for the glucose sensor.

17. The sensor system of claim 15, wherein the method implemented by the executable instructions further comprises:

obtaining temperature measurement data, wherein the nonlinear mapping operation is performed on the constant potential sensor current, the EIS output measurements, and the temperature measurement data to generate the blood glucose value.

18. The sensor system of claim 15, wherein the executable instructions define a sensor characterization model for the glucose sensor.

19. The sensor system of claim 15, wherein the nonlinear mapping operation comprises:

combining the constant potential sensor current and at least some of the EIS output measurements.

20. The sensor system of claim 15, wherein the glucose sensor is integrated with the sensor system.