TRANSCUTANEOUS ANALYTE SENSOR

• US 20110257895A1
• Filed: 06/29/2011
• Published: 10/20/2011
• Est. Priority Date: 08/01/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Brister, Mark, Brauker, James H., Goode, Paul
• Granted Patent: US 8,321,149 B2
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 2560/04 Constructional details of apparatus
• CPC Class Codes: A61B 2562/085 combined with means for recording calibration data
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• 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: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/6833 Adhesive patches
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots

Abstract

The present invention relates generally to systems and methods for measuring an analyte in a host. More particularly, the present invention relates to systems and methods for transcutaneous measurement of glucose in a host.

Claims

13. A system for monitoring a glucose concentration in a host, the system comprising:

a receiving module configured to receive sensor data indicative of a glucose concentration in a host over time generated by a substantially continuous glucose sensor and reference data from a reference analyte monitor; and

a processor module configured to;

determine a first rate of change of a glucose concentration of a host that is substantially time corresponding to a first reference data point of the reference data;

determine whether the first rate of change is within a range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans; and

calibrate the sensor data using the first reference data point only if the first rate of change is determined to be within the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans.

1. A method for monitoring a glucose concentration in a host, the method comprising:

receiving sensor data indicative of a glucose concentration in a host over a period of time, wherein the sensor data is generated by a substantially continuous glucose sensor;

receiving reference data from a reference analyte monitor; and

using a processor module to;

determine a first rate of change of a glucose concentration of a host that is substantially time corresponding to a first reference data point of the reference data;

determine whether the first rate of change is within a range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans; and

calibrate the sensor data using the first reference data point only if the first rate of change is determined to be within the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans.

2. The method of claim 1, wherein the maximum normally sustainable rates of change of glucose in humans is within of a range of about +/−

4 mg/dL/min.

3. The method of claim 1, wherein the reference data comprises a data point indicative of a glucose concentration measured by an in vitro single point glucose monitor.

4. The method of claim 1, wherein using the processor module to calibrate the sensor data comprises:

matching the first reference data point with a time-corresponding sensor data point of the sensor data;

forming or modifying a conversion function based at least in part of the matched data; and

converting the sensor data to glucose values using the formed or modified conversion function.

5. The method of claim 1, further comprising evaluating a concordance of the sensor data and the first reference data point of the reference data.

6. The method of claim 1, further comprising evaluating a clinical acceptability of a deviation of the first reference data point from a time-corresponding sensor data point of the sensor data and a risk of the deviation based on a glucose value indicated by at least one of the sensor data or the reference data.

7. The method of claim 1, further comprising using in vitro sensitivity information during the calibrating.

8. The method of claim 1, wherein using the processor module to determine the first rate of change is based on first sensor data of the sensor data generated during a first time period, the method further comprising determining a second rate of change based on second sensor data of the sensor generated during a second time period,

wherein the first rate of change is determined not to be within the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans, and

wherein the second rate of change is determined to be within the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans.

9. The method of claim 8, wherein using the processor module to calibrate comprises calibrating the at least some of the sensor data using a second reference data point of the reference data and not calibrating the sensor data using the first reference data point.

10. The method of claim 8, wherein the second reference data point time corresponds to the second rate of change.

11. The method of claim 1, wherein the first rate of change is determined using at least some of the sensor data.

12. The method of claim 11, wherein the at least some of the sensor data is calibrated sensor data.

14. The system of claim 13, wherein the maximum normally sustainable rates of change of glucose in humans is within of a range of about +/−

4 mg/dL/min.

15. The system of claim 13, wherein the reference data comprises a data point indicative of a glucose concentration measured by an in vitro single point glucose monitor.

16. The system of claim 13, wherein calibrating the sensor data comprises:

matching the first reference data point with a time-corresponding sensor data point of the sensor data;

forming or modifying a conversion function based at least in part of the matched data; and

converting the sensor data to glucose values using the formed or modified conversion function.

17. The system of claim 13, wherein the processor module is further configured to evaluate a concordance of the sensor data and the first reference data point of the reference data.

18. The system of claim 13, wherein the processor module is further configured to evaluate a clinical acceptability of a deviation of the first reference data point from a time-corresponding sensor data point of the sensor data and a risk of the deviation based on a glucose value indicated by the sensor data and/or the reference data.

19. The system of claim 13, wherein the processor module is further configured to use in vitro sensitivity information during the calibrating.

20. The system of claim 13, wherein determining the first rate of change is based on first sensor data of the sensor data generated during a first time period, and wherein the processor module is further configured to determine a second rate of change based on second sensor data of the sensor generated during a second time period.

21. The method of claim 13, wherein a second reference data point of the reference data substantially time corresponds to the second rate of change, and

22. The method of claim 21, wherein the calibrating comprises calibrating at least some of the sensor data using a second reference data point of the reference data and not calibrating the sensor data using the first reference data point when the first rate of change is determined to be outside the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans and the second reference data point is determined to be within the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans.

23. The method of claim 22, wherein the at least some of the sensor data is calibrated sensor data.

22-1. The system of claim 13, wherein the first rate of change is determined using at least some of the sensor data.