Low oxygen in vivo analyte sensor

• US 10,265,000 B2
• Filed: 08/03/2017
• Issued: 04/23/2019
• Est. Priority Date: 01/17/2006
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Shults, Mark C., Rhodes, Rathbun K., Updike, Stuart J., Brauker, James H.
• Primary Examiner(s): Messersmith, Eric J
• Application Number:
  US15/668,541
• Publication Number:
  US 20170325726A1
• Time in Patent Office: 628 Days
• Field of Search: 600345, 600347, 600365
• 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 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• 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: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive

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 and subcutaneous measurement of glucose in a host.

Claims

1. An implantable glucose sensor system comprising:

a glucose sensor comprising;

an implantable body comprising an electrode configured to measure a glucose level in a host; and

a membrane disposed over the electrode, wherein the membrane comprises;

a first layer configured to limit transport of glucose to the electrode;

a second layer comprising an enzyme to catalyze a reaction of glucose and oxygen as a co-reactant, wherein the enzyme is configured to use oxygen from a biological fluid surrounding the membrane to catalyze the reaction; and

a third layer configured to reduce a flux of an interferent, wherein the third layer comprises polymers having ionic groups; and

a sensor electronics unit operably connected to the electrode and configured to measure a current produced by the electrode;

wherein the the glucose sensor is configured to measure glucose concentration with substantial linearity at glucose concentrations of up to 400 mg/dL at an oxygen concentration of 0.6 mg/L.

2. The implantable glucose sensor system of claim 1, wherein the sensor electronics unit is configured to directly measure the current produced by the electrode.

3. The implantable glucose sensor system of claim 1, wherein the glucose sensor further comprises a biointerface layer configured to support tissue ingrowth.

4. The implantable glucose sensor system of claim 1, further comprising an analog-to-digital converter configured to translate the current into a digital signal.

5. The implantable glucose sensor system of claim 1, wherein the electrode comprises an exposed electroactive working electrode surface with a surface area of from about 0.00002 in² to about 0.0079 in².

6. The implantable glucose sensor system of claim 1, wherein the first layer is configured to have a permeability ratio of at least about 50:

1 of oxygen to glucose.

7. The implantable glucose sensor system of claim 1, wherein the first layer is configured to have a permeability ratio of at least about 200:

1 of oxygen to glucose.

8. The implantable glucose sensor system of claim 1, wherein the sensor system is configured to have, in operation, a sensitivity of from about 1 pA/mg/dL to about 100 pA/mg/dL.

9. The implantable glucose sensor system of claim 1, wherein the sensor system is configured to have, in operation, a sensitivity of from about 5 pA/mg/dL to about 25 pA/mg/dL.

10. The implantable glucose sensor system of claim 1, wherein the sensor system is configured to have, in operation, a sensitivity of from about 3.5 to about 7.5 pA/mg/dL.