DEVICE AND METHOD FOR DETERMINING ANALYTE LEVELS

• US 20100204559A1
• Filed: 04/19/2010
• Published: 08/12/2010
• 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, Rathbun K.
• Granted Patent: US 7,970,448 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• 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 an electrode configured for implantation in a subcutaneous tissue of a host, wherein the sensing mechanism is configured to continuously measure an analyte concentration, whereby sensor data associated with the subcutaneous analyte concentration is generated; and

electronic circuitry operably connected to the sensing mechanism and configured to calibrate the sensor data during a useful life of the system using pre-implant calibration information and a reference analyte value obtained after implantation of the sensor, wherein the system is configured to provide a substantially accurate measurement of the analyte concentration in the host such that at least 95% of calibrated sensor analyte values are within 25% of actual analyte values during the useful life of the system.

2. The system of claim 1, wherein the pre-implant calibration information comprises a single point value obtained from an in vitro calibration.

3. The system of claim 2, wherein the in vitro calibration is obtained by measuring at least two different analyte concentrations.

4. The system of claim 2, wherein the in vitro calibration is obtained at about 37 degrees C.

5. The system of claim 1, wherein the reference analyte value is correlated with a sensor data value.

6. The system of claim 5, wherein the reference analyte value and the sensor data value are used to adjust the pre-implant calibration information during calibration.

7. The system of claim 5, wherein the reference analyte value is time shifted relative to the sensor data value.

8. The system of claim 1, wherein the analyte is glucose, and wherein the sensing mechanism is configured to respond substantially linearly to changes in glucose concentration at glucose concentrations ranging from about 40 mg/dL to about 500 mg/dL.

9. The system of claim 1, wherein the system is configured to provide a stable sensor offset during the useful life of the sensor.

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

11. The system of claim 1, wherein the electronic circuitry is configured to physically couple the sensing mechanism.

12. The system of claim 1, wherein the electronic circuitry is configured to couple, via radio telemetry, the sensing mechanism.

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

14. The system of claim 1, wherein the useful life of the system is more than about 3 days of implantation.

15. The system of claim 1, wherein the useful life of the system is more than about 5 days of implantation.

16. The system of claim 1, wherein the useful life of the system is more than about 7 days of implantation.

17. The system of claim 1, wherein the useful life of the system is more than about one month of implantation.

18. A method for processing sensor data from a continuous analyte sensor, comprising:

receiving sensor data from an analyte sensor, the sensor data indicative of an analyte concentration in a host;

calibrating the sensor data during a useful life of system using pre-implant calibration information and a reference analyte value obtained after implantation of the sensor; and

generating a substantially accurate measurement of the analyte concentration, such that at least 95% of calibrated sensor analyte values are within 25% of actual analyte values during the useful life of the system.

19. The method of claim 18, wherein the pre-implant calibration information comprises a single point value obtained from an in vitro calibration.

20. The method of claim 19, wherein the in vitro calibration is obtained by measuring at least two different analyte concentrations.

21. The method of claim 19, wherein the in vitro calibration is obtained at about 37 degrees C.

22. The method of claim 18, wherein the reference analyte value is correlated with a sensor data value during calibration.

23. The method of claim 22, further comprising using the reference analyte value and the sensor data value to adjust the pre-implant calibration information during calibration.

24. The method of claim 22, wherein the reference analyte value is time shifted relative to the sensor data value.

25. The method of claim 18, wherein the analyte is glucose, and wherein the sensing mechanism is configured to respond substantially linearly to changes in glucose concentration at glucose concentrations ranging from about 40 mg/dL to about 500 mg/dL.

26. The method of claim 18, further comprising maintaining a stable sensor offset during the useful life of the system.

27. The system of claim 18, further comprising determining trends in analyte concentration.

28. The method of claim 18, wherein the analyte is glucose.

29. The method of claim 18, wherein the useful life of the system is greater than about 3 days of implantation.

30. The method of claim 18, wherein the useful life of the system is greater than about 5 days of implantation.

31. The method of claim 18, wherein the useful life of the system is greater than about 7 days of implantation.

32. The method of claim 18, wherein the useful life of the system is about one month of implantation.