Device and method for determining analyte levels

• US 7,835,777 B2
• Filed: 12/22/2009
• Issued: 11/16/2010
• Est. Priority Date: 03/04/1997
• Status: Expired due to Fees

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Shults, Mark C., Updike, Stuart J., Rhodes, Rathbun K.
• Primary Examiner(s): Nasser; Robert L
• Application Number:
  US12/645,270
• Publication Number:
  US 20100099971A1
• Time in Patent Office: 329 Days
• Field of Search: None
• 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 sensor comprising one or more electrodes configured for implantation in a subcutaneous tissue of a host, wherein the sensor is configured to continuously measure an analyte concentration in the host, whereby sensor data indicative of the subcutaneous analyte concentration is obtained; and

an electronic system operably connected to the sensor and configured to calibrate the sensor data in real-time using a reference value determined by analysis of blood, wherein the electronic system is configured to calibrate the sensor data by correlating the reference value with a time-spaced sensor data value of the sensor data.

2. The system of claim 1, wherein the electronic system 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 calibrated sensor data values are within 25% of corresponding values determined by analysis of blood 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 sensor is configured to continuously measure the analyte concentration in the host for at least about 3 days.

6. The system of claim 1, wherein the sensor is configured to continuously measure the analyte concentration in the host for at least about 5 days.

7. The system of claim 1, wherein the sensor is configured to continuously measure the analyte concentration in the host for at least about 7 days.

8. The system of claim 1, wherein the electronic system is physically coupled to the sensor.

9. The system of claim 1, wherein the electronic system is operably connected via radio telemetry to the sensor.

10. The system of claim 1, wherein an offset current defined by a current at 0 mg/dL is configured to remain stable during a period of time of continuous measurement of the 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 system, data from a sensor configured to continuously measure a subcutaneous analyte concentration in a host, wherein calibrating comprises correlating a reference value determined by analysis of blood with a time-spaced sensor data value of the sensor data, and wherein the calibrating is performed during a period of time of continuous subcutaneous analyte concentration measurement.

13. The method of claim 12, wherein the electronic system 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 calibrated sensor data values are within 25% of corresponding values determined by analysis of blood 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 sensor is configured to continuously measure the analyte concentration in the host for at least about 3 days.

17. The method of claim 12, wherein the sensor is configured to continuously measure the analyte concentration in the host for at least about 5 days.

18. The method of claim 12, wherein the sensor is configured to continuously measure the analyte concentration in the host for at least about 7 days.

19. The method of claim 12, wherein the electronic system is configured to be physically coupled to the sensor.

20. The method of claim 12, further comprising receiving the sensor data via radio telemetry using a receiver of the electronic system.

21. The method of claim 12, wherein an offset current defined by a current at 0 mg/dL is configured to remain stable over the period of time.

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