ANALYTE SENSOR

• US 20140058235A1
• Filed: 11/05/2013
• Published: 02/27/2014
• Est. Priority Date: 08/01/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Li, Ying, Kamath, Apurv Ullas, Yang, Richard C., Brister, Mark C.
• Granted Patent: US 10,052,055 B2
• Time in Patent Office: Days
• US Class Current: 600/345
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• 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 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14735 comprising an immobilised reagent
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• 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 5/15003 for venous or arterial blood
• CPC Class Codes: A61B 5/150992 Blood sampling from a fluid line external to a patient, such as a catheter line, combined with an infusion line; blood sampling from indwelling needle sets, e.g. sealable ports, luer couplings, valves tubing connectors and couplings A61M39/00
• CPC Class Codes: A61B 5/155 Devices specially adapted for continuous or multiple sampling, e.g. at predetermined intervals devices loaded with multiple lancets simultaneously A61B5/15146
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/6849 : in combination with a needle set
• CPC Class Codes: A61B 5/7275 : Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/743 : Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: A61M 2005/14296 : Pharmacokinetic models
• CPC Class Codes: A61M 2230/201 : Glucose concentration
• CPC Class Codes: A61M 5/14 : Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61M 5/16804 : Flow controllers
• CPC Class Codes: A61M 5/1723 : using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: C12Q 1/001 : Enzyme electrodes
• CPC Class Codes: C12Q 1/006 : for glucose
• CPC Class Codes: G16H 10/40 : for data related to laboratory analysis, e.g. patient specimen analysis
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection
• CPC Class Codes: G16H 40/40 : for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades
• CPC Class Codes: G16H 40/63 : for local operation
• CPC Class Codes: Y02A 90/10 : Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Systems and methods of use for continuous analyte measurement of a host'"'"'s vascular system are provided. In some embodiments, a continuous glucose measurement system includes a vascular access device, a sensor and sensor electronics, the system being configured for insertion into communication with a host'"'"'s circulatory system.

Claims

1. A method for evaluating a change in a sensitivity of an implanted analyte sensor over a predetermined time period, comprising:

receiving sensor data from an analyte sensor implanted in a host, wherein the implanted sensor is configured to generate sensor data, wherein the sensor data comprises one or more sensor analyte values measured in a biological sample of a host;

intermittently calculating a sensitivity of the analyte sensor; and

evaluating, using an electronic device, a change in sensitivity by evaluating a plurality of time-spaced sensitivity calculations over a predetermined time period, wherein evaluating a change in sensitivity is based at least in part on using a priori sensitivity information throughout a sensor session, wherein the plurality of time spaced sensitivity calculations are not based on a blood-glucose measurement.

2. The method of claim 1, wherein the predetermined time period is less than or equal to about 30 minutes.

3. The method of claim 1, wherein the predetermined time period is less than or equal to about 20 minutes.

4. The method of claim 1, wherein the predetermined time period is less than or equal to about 10 minutes.

5. The method of claim 1, wherein evaluating a change in sensitivity comprises evaluating at least two sensitivity measurements during the predetermined time period.

6. The method of claim 5, further comprising averaging and/or filtering the at least two sensitivity measurements prior to evaluating the at least two sensitivity measurements.

7. The method of claim 1, wherein evaluating a change in sensitivity comprises comparing the change in sensitivity with one or more criteria.

8. The method of claim 7, further comprising using a most recent sensitivity calculation evaluated to calibrate the analyte sensor when the change in sensitivity meets one or more criteria.

9. The method of claim 7, further comprising not using a most recent sensitivity calculation evaluated to calibrate the analyte sensor when the change in sensitivity does not meet one or more criteria.

10. The method of claim 1, wherein evaluating a change in sensitivity is iteratively performed on the plurality of time-spaced sensitivity calculations over the predetermined time period.

11. The method of claim 1, wherein the predetermined time period is at least about 30 minutes.

12. The method of claim 1, wherein the predetermined time period is at least about 60 minutes.

13. The method of claim 1, wherein the predetermined time period is at least about 120 minutes.

14. The method of claim 1, wherein evaluating a change in sensitivity is iteratively performed on the plurality of time-spaced sensitivity calculations over the predetermined time period.

15. The method of claim 1, wherein evaluating a change in sensitivity comprises evaluating all sensitivity calculations over a sensor session.

16. The method of claim 1, wherein the a priori sensitivity information defines a range of acceptable change in sensitivity.

17. A method for evaluating a change in a sensitivity of an implanted analyte sensor over a predetermined time period, comprising:

receiving sensor data from an analyte sensor implanted in a host, wherein the implanted sensor is configured to generate sensor data, wherein the sensor data comprises one or more sensor analyte values measured in a biological sample of a host;

intermittently, using an electronic device, calculating a sensitivity of the analyte sensor;

measuring a change in sensitivity by evaluating a parameter indicative of a change in solute transport of a membrane of the analyte sensor; and

auto-calibrating the analyte sensor responsive to measurement of the change in sensitivity.

18. A method for evaluating a change in a sensitivity of an analyte sensor over a predetermined time period, the method comprising:

receiving sensor data from an analyte sensor, wherein the sensor data comprises one or more sensor analyte values measured in a biological sample of a host;

intermittently calculating a sensitivity of the analyte;

filtering at least two sensitivity values, whereby filtered sensitivity values are obtained; and

evaluating, using an electronic device, a change in sensitivity by evaluating the filtered sensitivity values over a predetermined time period, wherein evaluating a change in sensitivity is based at least in part on using a priori sensitivity information throughout a sensor session.