DEVICE AND METHOD FOR DETERMINING ANALYTE LEVELS

• US 20100099971A1
• Filed: 12/22/2009
• Published: 04/22/2010
• Est. Priority Date: 03/04/1997
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Shults, Mark C., Updike, Stuart J., Rhodes, Rathburn K.
• Granted Patent: US 7,835,777 B2
• Time in Patent Office: Days
• US Class Current: 600/347
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• 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: C12Q 1/006 for glucose

Abstract

Devices and methods for determining analyte levels are described. The devices and methods allow for the implantation of analyte-monitoring devices, such as glucose monitoring devices, that result in the delivery of a dependable flow of blood to deliver sample to the implanted device. The devices comprise a unique microarchitectural arrangement in the sensor region that allows accurate data to be obtained over long periods of time.

Claims

1. A system for processing sensor data from a continuous analyte sensor, comprising:

a sensing mechanism comprising one or more electrodes configured for implantation in a subcutaneous tissue of a host, wherein the sensing mechanism is configured to continuously measure an analyte concentration in the host for a period of time, whereby sensor data associated with the subcutaneous analyte concentration is obtained; and

electronic circuitry operably connected to the sensing mechanism and configured to calibrate the sensor data associated with the subcutaneous analyte concentration in real-time using one or more reference values determined by analysis of blood, wherein the electronic circuitry is configured to calibrate the sensor data by correlating a reference value with a time-spaced sensor data value.

2. The system of claim 1, wherein the electronic circuitry is configured to determine trends in analyte concentration.

3. The system of claim 1, wherein the system is configured to provide a substantially stable measurement of the analyte concentration in the host, wherein at least 95% of analyte concentration values measured by the signal are within 25% of one or more reference values over a useful life of the device.

4. The system of claim 1, wherein the analyte is glucose, and wherein the calibration is substantially linear at a glucose concentration of from about 40 mg/dL to about 500 mg/dL.

5. The system of claim 1, wherein the period of time is greater than about 3 days.

6. The system of claim 1, wherein the period of time is greater than about 5 days.

7. The system of claim 1, wherein the period of time is greater than about 7 days.

8. The system of claim 1, wherein the electronic circuitry is physically coupled to the sensing mechanism.

9. The system of claim 1, wherein the electronic circuitry is coupled via radio telemetry to the sensing mechanism.

10. The system of claim 1, wherein an offset current defined by a current at 0 mg/dL remains stable during a period of time of continuous measurement of an analyte concentration in the host.

11. The system of claim 1, wherein the analyte is glucose.

12. A method for processing real-time sensor data from a continuous analyte sensor, comprising:

calibrating, with an electronic device, data from a sensing mechanism configured to continuously measure a subcutaneous analyte concentration in a host for a period of time, wherein calibrating comprises using one or more reference values determined by analysis of blood by correlating a reference value with a time-spaced sensor data value, wherein the calibrating is performed during the period of time of continuous subcutaneous analyte concentration measurement.

13. The method of claim 12, wherein the electronic circuitry is configured to determine trends in analyte concentration.

14. The method of claim 12, wherein the method is configured to provide a substantially stable measurement of the analyte concentration in the host, wherein at least 95% of analyte concentration values measured by the signal are within 25% of one or more reference values over a useful life of the device.

15. The method of claim 12, wherein the analyte is glucose, and wherein the calibration is substantially linear at a glucose concentration of from about 40 mg/dL to about 500 mg/dL.

16. The method of claim 12, wherein the period of time is greater than about 3 days.

17. The method of claim 12, wherein the period of time is greater than about 5 days.

18. The method of claim 12, wherein the period of time is greater than about 7 days.

19. The method of claim 12, wherein the electronic circuitry is physically coupled to the sensing mechanism.

20. The method of claim 12, wherein the electronic circuitry is coupled via radio telemetry to the sensing mechanism.

21. The method of claim 12, wherein an offset current defined by a current at 0 mg/dL remains stable during a period of time of continuous measurement of an analyte concentration in the host.

22. The method of claim 12, wherein the analyte is glucose.