Transcutaneous analyte sensor

• US 8,311,749 B2
• Filed: 05/26/2011
• Issued: 11/13/2012
• Est. Priority Date: 08/01/2003
• Status: Expired due to Term

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Brauker, James H., Kamath, Apurv Ullas, Goode, Paul, Brister, Mark
• Primary Examiner(s): Lau, Tung S
• Application Number:
  US13/116,871
• Publication Number:
  US 20110231107A1
• Time in Patent Office: 537 Days
• Field of Search: 702/19
• 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

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

a substantially continuous glucose sensor configured to produce sensor data indicative of a glucose concentration in a host;

a sensor data receiving module configured to receive the sensor data from the substantially continuous glucose sensor;

a reference data receiving module configured to receive reference data from an in vitro single point glucose monitor, the in vitro single point glucose monitor configured to receive a biological sample from the host and to measure a glucose concentration in the sample;

a processor module in communication with the sensor data receiving module and the reference data receiving module; and

computer readable memory comprising;

instructions configured to cause the processor module to calibrate the sensor data received from the substantially continuous glucose sensor;

instructions configured to cause the processor module to determine a rate of change of the calibrated sensor data;

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

instructions configured to allow the processor module to calibrate the sensor data using the reference data when the rate of change is within the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans, but not allow the processor module to calibrate the sensor data using the reference data when the rate of change is outside the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans.

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

4 mg/dL/min.

3. The system of claim 1, wherein the substantially continuous glucose sensor is configured to be implanted in a subcutaneous space of the host.

4. The system of claim 1, wherein the sensor data is indicative of the concentration of glucose in a subcutaneous space of the host.

5. The system of claim 1, wherein instructions configured to cause the processor module to cailbrate the sensor data comprise calibrating the sensor data using the reference data comprises forming a matched data pair by matching a sensor data point of the sensor data with a time-corresponding reference data point of the reference data and calibrating the sensor data using the matched data pair.

6. The system of claim 5, wherein the instructions configured to allow the processor module to calibrate the sensor data comprise instructions configured to cause the processor module to compensate for a time lag between the reference glucose data and the sensor data.

7. The system of claim 1, wherein the instructions configured to allow the processor module to calibrate the sensor data comprise instructions configured to cause the processor module to evaluate the sensor data to determine a sensor break-in and to request the reference glucose measurement responsive to the sensor break-in determination.

8. The system of claim 1, further comprising a hand-held computing device, wherein the sensor data receiver module, the reference data receiver module, the processor module and the computer readable medium are housed within the hand-held computing device.

9. A non-transitory computer-readable storage medium including code which when executed by at least one processor causes operations comprising:

calibrating sensor data received from a substantially continuous glucose sensor;

determining a rate of change of the calibrated sensor data;

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

receiving reference data generated from an in vitro glucose monitor; and

calibrating sensor data using the reference data generated from an in vitro glucose monitor only when the rate of change is within the range of rates of change delimited by maximum normally sustainable rates of change of glucose in humans.

10. The non-transitory computer-readable storage medium of claim 9, wherein the maximum normally sustainable rates of change of glucose in humans is within a range of about +/−

4 mg/dL/min.

11. The non-transitory computer-readable storage medium of claim 9, wherein calibrating the sensor data using the time-corresponding reference data comprises forming a matched data pair by matching a sensor data point of the sensor data with a time-corresponding reference data point and calibrating the sensor data using the matched data pair.

12. The non-transitory computer-readable storage medium of claim 9, wherein calibrating the sensor data using the time-corresponding reference data further comprises compensating for a time lag between the reference glucose data and the sensor data.