Device and method for determining analyte levels

• US 8,676,288 B2
• Filed: 06/22/2011
• Issued: 03/18/2014
• 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): Mallari, Patricia
• Assistant Examiner(s): D'ANGELO, MICHAEL J
• Application Number:
  US13/166,685
• Publication Number:
  US 20110253533A1
• Time in Patent Office: 1,000 Days
• Field of Search: 600/309, 600/316, 600345-347, 600/365, 435/4, 435/14, 436/68, 422/50, 422420-429, 20440301-40315, 702/23, 604 64- 66
• US Class Current: 600/345
• 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 device for measuring glucose in a bodily fluid, the device comprising:

a sensor operably connected to an electronic circuit and configured to continuously measure a signal associated with a glucose concentration in a host, the sensor comprising a working electrode and a reference electrode, wherein the working electrode and the reference electrode are configured for implantation in a subcutaneous tissue of the host; and

a membrane disposed on a portion of the sensor, configured to provide at least two phases of sensor function, wherein the at least two phases of sensor function comprise;

a first phase that occurs after implantation of the device in the subcutaneous tissue and during which the signal provides an unstable measurement of the glucose concentration in the host; and

a second phase that occurs after the first phase and during which the signal provides a stable measurement of the glucose concentration in the subcutaneous tissue of the host, wherein at least 95% of glucose concentration values measured by the signal are within 25% of one or reference glucose values over a period of time no less than 3 days in the subcutaneous tissue of the host, and wherein the one or more reference values are determined by analysis of the host'"'"'s blood glucose;

wherein the device is configured to respond substantially linearly to changes in glucose concentration at a glucose concentration of up to about 400 mg/dL.

2. The device of claim 1, wherein the membrane comprises an electrolyte layer, wherein the electrolyte layer comprises a flexible, hydrophilic material.

3. The device of claim 1, wherein the membrane comprises a resistance layer comprising a semipermeable membrane configured to control a flux of oxygen and glucose therethrough.

4. The device of claim 1, further comprising a housing filled with a material comprising a resin, wherein the resin secures the electronic circuit within the housing.

5. The device of claim 1, further comprising an apparatus operatively connected to the electronic circuit and configured for transmitting data to a location external to the device.

6. The device of claim 5, wherein the electronic circuit is configured to transmit data at intervals.

7. The device of claim 1 further comprising a housing comprising a cavity contained therewithin.

8. The device of claim 7, wherein the sensor is situated within the housing cavity.

9. The device of claim 1, wherein the membrane is configured to restrict passage of interfering species therethrough.

10. The device of claim 1, wherein the membrane comprises a cross-linked polymer and is configured to control a flux of oxygen and glucose therethrough.

11. The device of claim 1, wherein the sensor comprises an electrochemical mechanism.

12. The device of claim 1, wherein the sensor comprises a non-enzymatic mechanism.

13. The device of claim 1, wherein the sensor comprises a resonance mechanism.

14. The device of claim 1, wherein the sensor comprises an acoustic wave mechanism.

15. The device of claim 1, wherein the sensor comprises an optical mechanism.

16. The device of claim 1, wherein the device is configured to provide stabilization of the membrane to reduce motion artifact.

17. A device for measuring glucose in a bodily fluid, the device comprising:

a sensor configured to generate a signal associated with a concentration of glucose in a host, wherein the sensor comprises a working electrode and a reference electrode, and wherein the working electrode and the reference electrode are configured for implantation in a subcutaneous tissue of the host; and

a membrane disposed on a portion of the sensor, wherein the membrane is configured to control a flux of oxygen and glucose therethrough;

wherein the device is configured, while implanted in the subcutaneous tissue of the host, to respond substantially linearly to changes in glucose concentration at a glucose level up to 400 mg/dL, wherein the membrane provides for at least 95% of glucose concentration values measured by the signal being within 25% of one or more reference glucose values for a useful life of the device of no less than 3 days in the subcutaneous tissue of the host, and wherein the reference values are determined by analysis of the host'"'"'s blood glucose.

18. The device of claim 17, wherein the device further comprises an apparatus configured to transmit data to a location external to the device.

19. The device of claim 17, wherein the membrane comprises an electrolyte layer, wherein the electrolyte layer comprises a flexible, hydrophilic material.

20. The device of claim 17, wherein the membrane is configured to restrict passage of interfering species therethrough.

21. The device of claim 17, wherein the sensor comprises an electrochemical mechanism.

22. The device of claim 17, wherein the sensor comprises a non-enzymatic mechanism.

23. The device of claim 17, wherein the sensor comprises a resonance mechanism.

24. The device of claim 17, wherein the sensor comprises an acoustic wave mechanism.

25. The device of claim 17, wherein the sensor comprises an optical mechanism.

26. The device of claim 17, wherein the device is configured to provide stabilization of the membrane to reduce motion artifact.