DEVICES, SYSTEMS, AND METHODS TO COMPENSATE FOR EFFECTS OF TEMPERATURE ON IMPLANTABLE SENSORS

• US 20150090589A1
• Filed: 12/11/2014
• Published: 04/02/2015
• Est. Priority Date: 06/29/2012
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Estes, Michael J., Blackwell, Jennifer, Bohm, Sebastian, Boock, Robert J., Simpson, Peter C., Wightlin, Matthew D., Pryor, Jack
• Granted Patent: US 10,908,114 B2
• Time in Patent Office: Days
• US Class Current: 204/403.1
• 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: G01N 27/403 Cells and electrode assemblies

Abstract

Systems and methods for compensating for effects of temperature on implantable sensors are provided. In some embodiments, systems and methods are provided for measuring a temperature to determine a change in temperature in a sensor environment. In certain embodiments, a temperature compensation factor is determined based on a change in temperature of the sensor environment. The temperature compensation factor can be used in processing raw data of an analyte signal to report a more accurate analyte concentration.

Claims

1. A device for continuous in vivo measurement of glucose concentrations in a host, comprising:

at least one electrode operatively connected to electronic circuitry configured to generate a signal representative of a concentration of glucose in a host;

at least one membrane located over at least a portion of the electrode, the at least one membrane comprising an enzyme configured to catalyze a reaction of glucose and oxygen from a biological fluid in contact with the membrane in vivo; and

a temperature sensor configured to measure at least one of an in vivo temperature or a change in temperature in vivo.

2. The device of claim 1, wherein the at least one electrode comprises a first electrode and a second electrode.

3. The device of claim 2, wherein the at least one membrane comprises a first membrane located over at least a portion of the first electrode and a second membrane located over at least a portion of the second electrode, and wherein the first membrane and the second membrane each have a different temperature coefficient.

4. The device of claim 3, wherein the first membrane and the second membrane each have a different composition.

5. The device of claim 3, wherein the first membrane and the second membrane are each configured to exhibit a different change in dimension in response to a change in temperature in vivo.

6. The device of claim 3, wherein the first membrane and the second membrane are each configured to exhibit a different change in electrical conductivity in response to a change in temperature in vivo.

7. The device of claim 3, further comprising sensor electronics configured to apply at least one potential to at least one of the first electrode or the second electrode.

8. The device of claim 7, wherein the at least one potential includes a first potential that is applied to the first electrode and a second potential that is applied to the second electrode.

9. The device of claim 8, wherein the first potential is different from the second potential.

10. The device of claim 7, further comprising a connector configured to connect the first electrode and the second electrode, wherein the connector comprises a thermistor.

11. The device of claim 10, wherein the connector further comprises a diode.

12. The device of claim 10, wherein the connector further comprises a capacitor.

13. The device of claim 7, further comprising a third electrode, wherein the first electrode and the second electrode are each working electrodes and the third electrode is a reference electrode.

14. The device of claim 13, further comprising a connector configured to connect the first electrode, the second electrode, and the third electrode, wherein the connector comprises a thermistor and a transistor.

15. The device of claim 2, wherein the temperature sensor is configured to measure a stimulus signal passed across the first electrode and the second electrode.

16. The device of claim 15, wherein the stimulus signal is an impedance measurement.

17. The device of claim 2, further comprising a first reference electrode or a first counter electrode, and a second reference electrode or a second counter electrode, wherein the temperature sensor is configured to measure a stimulus signal passed between the first electrode and the second electrode.

18. The device of claim 2, wherein the device is configured to apply a first bias potential to the first electrode and a second bias potential to the second electrode, wherein the second bias potential varies over time, and wherein the temperature sensor is configured to measure a change in a property of the device in response to a change in the second bias potential.

19. The device of claim 1, wherein the temperature sensor is configured to measure a change in sensitivity to glucose in response to a change in temperature in vivo.

20. The device of claim 1, wherein the at least one electrode comprises a thermally conductive core, and wherein the temperature sensor is configured to measure a change in temperature of the thermally conductive core.

21. The device of claim 1, wherein the at least one electrode comprises a portion comprising a shape memory material, and wherein the temperature sensor is configured to measure a pressure change of the shape memory material responsive to a temperature change in vivo.

22. The device of claim 1, wherein the temperature sensor comprises a fiber optic sensor configured to measure a temperature in vivo, and wherein the fiber optic sensor is embedded within the electrode or affixed to the electrode.

23. The device of claim 1, wherein the device comprises a processor configured to use a priori sensitivity information.