Electrochemical sensor including multiple work electrodes and common reference electrode

Patent metadata

Field	Value
Publication number	US-11744492-B2
Application number	US-201816116346-A
Country	US
Kind code	B2
Filing date	Aug 29, 2018
Priority date	Aug 29, 2018
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

A biocompatible medical device may include an electrochemical sensor including a common reference electrode; at least one counter electrode; and a work electrode platform comprising a plurality of respective work electrodes, each respective work electrode electrically coupled to the common reference electrode and comprising a respective reagent substrate configured to react with a respective analyte to produce a respective signal indicative of a concentration of the respective analyte; and processing circuitry operatively coupled to the electrochemical sensor, and configured to receive from the electrochemical sensor a plurality of signals from the plurality of respective work electrodes; identify the respective signal corresponding to a respective selected work electrode; and process the identified signal to determine the concentration of the respective analyte associated with the respective selected work electrode.

First claim

What is claimed is:

1. A biocompatible medical device comprising:
a biocompatible housing configured for insertion through skin and into interstitial fluid of a patient;
an electrochemical sensor at least one of within or affixed to the housing, the electrochemical sensor comprising:
a dielectric substrate defining a first major surface;
an interconnect layer on the first major surface and defining a second major surface opposing the first major surface;
a single common reference electrode;
a single common counter electrode;
a work electrode platform comprising a plurality of respective work electrodes, wherein each respective work electrode of the plurality of respective work electrodes is adjacent at least one other respective work electrode of the plurality of respective work electrodes; and
a plurality of dielectric barriers, wherein a dielectric barrier of the plurality of dielectric barriers is disposed between each pair of adjacent work electrodes,
wherein the plurality of respective work electrodes are disposed on the second major surface,
wherein the interconnect layer electrically couples the common reference electrode and the common counter electrode to each respective work electrode of the plurality of respective work electrodes, and
wherein each respective work electrode of the plurality of respective work electrodes comprises a respective reagent substrate configured to react with a respective analyte to produce a respective signal indicative of a concentration of the respective analyte; and

processing circuitry at least one of within or affixed to the housing and operatively coupled to the electrochemical sensor, wherein the processing circuitry is configured to:
receive from the electrochemical sensor a plurality of signals from the plurality of respective work electrodes;
identify the respective signal corresponding to a respective selected work electrode of the plurality of respective work electrodes; and
determine, based on the identified respective signal, the concentration of the respective analyte associated with the respective selected work electrode, wherein to determine the concentrations of the respective analytes associated with the respective selected work electrodes, the processing circuitry is further configured to selectively power a different respective work electrode of the plurality of respective work electrodes before receiving the respective signal corresponding to the respective selected work electrode of the plurality of respective work electrodes.

2. The biocompatible medical device of claim 1 , wherein at least a portion of the work electrode platform is configured to be fluidly coupled to an environment surrounding the biocompatible medical device.

3. The biocompatible medical device of claim 1 , wherein a height of the biocompatible medical device is approximately 2.35 millimeters, wherein a width of the biocompatible medical device is approximately 10.5 millimeters, and wherein a length of the biocompatible medical device is approximately 10.5 millimeters.

4. The biocompatible medical device of claim 1 , further comprising an antenna configured to transmit data representative of the concentration of the respective analyte to an external device.

5. The biocompatible medical device of claim 1 , wherein at least one work electrode of the plurality of respective work electrodes comprises a membrane disposed on the respective reagent substrate, and wherein the respective membrane is permeable to the respective analyte.

6. The biocompatible medical device of claim 5 , wherein the membrane comprises a limiting membrane, a selective ion transfer membrane, or a limiting membrane and a selective ion transfer membrane.

7. The biocompatible medical device of claim 5 , wherein the membrane comprises an ionophore.

8. The biocompatible medical device of claim 5 , wherein the at least one respective work electrode comprises a limiting membrane on the respective reagent substrate and a selective ion transfer membrane on the limiting membrane.

9. The biocompatible medical device of claim 5 , wherein the at least one respective work electrode comprises a selective ion transfer membrane on the respective reagent substrate and a limiting membrane on the selective ion transfer membrane.

10. The biocompatible medical device of claim 5 , wherein the membrane includes at least one ionophore selected from the group consisting of: amino methylated polystyrene salicylaldehyde, dibenzo-18-crown-6, cezomycin, enniatin, gramicidin A, lasalocid, macrolides, monensin, narasin, nigericin, nigericin sodium salt, nonactin, polyimide/lycra blend, salinomycin, valinomycin, or mixtures thereof.

11. The biocompatible medical device of claim 1 , wherein each respective work electrode of the plurality of respective work electrodes comprises a respective membrane disposed on the respective reagent substrate, and wherein the respective membrane is selectively permeable to the respective analyte.

12. The biocompatible medical device of claim 1 , wherein at least one of the respective reagent substrates comprises an oxidase enzyme.

13. The biocompatible medical device of claim 1 , wherein the respective reagent substrate includes at least one enzyme selected from the group consisting of: glucose oxidase, creatinine amidohydrolase, creatine amidinohydrolase, sarcosine oxidase, carbonic anhydrase, choline oxidase, horseradish peroxidase, thiamine oxidase, urease, glycerol-3-phosphate oxidase, L-amino acid oxidase, lactate oxidase, catalase alkaline phosphatase, alcohol oxidase, D-amino acid oxidase, cholesterol oxidase, pyridoxal oxidase, and NAD(P)H oxidase, and pyruvate oxidase, or mixtures thereof.

14. The biocompatible medical device of claim 1 , wherein a length of each respective work electrode of the plurality of respective work electrodes is between about 0.25 millimeters and about 0.75 millimeters, and wherein a width of each respective work electrode of the plurality of respective work electrodes is between about 0.25 millimeters and about 0.75 millimeters.

15. The biocompatible medical device of claim 1 , wherein a length of the common counter electrode is between about 7.5 millimeters and about 10 millimeters, and wherein a width of the common counter electrode is between about 7.5 millimeters and about 10 millimeters.

16. The biocompatible medical device of claim 1 , wherein the work electrode platform comprises the plurality of dielectric barriers disposed between the respective pairs of adjacent respective work electrodes of the plurality of respective work electrodes.

17. The biocompatible medical device of claim 1 , wherein the interconnect layer comprises at least one electrical interconnect comprising chromium, a gold chromium alloy, titanium, a titanium gold alloy, or platinum.

18. The biocompatible medical device of claim 1 , wherein the plurality of respective work electrodes comprises:
a first work electrode comprising a first reagent substrate configured to react with sodium ions;
a second work electrode comprising a second reagent substrate configured to react with chloride ions;
a third work electrode comprising a third reagent substrate configured to react with blood urea nitrogen;
a fourth work electrode comprising a fourth reagent substrate configured to react with glucose;
a fifth work electrode comprising a fifth reagent substrate configured to react with potassium;
a sixth work electrode comprising a sixth reagent substrate configured to react with bicarbonate or carbon dioxide; and
a seventh work electrode compr

Assignees

• Medtronic Inc

Inventors

• Hahn Daniel
• Askarinya Mohsen
• Carney James K
• Kinzie Patrick W
• Lorenz Marckmann Jennifer
• Schulhauser Randal C
• Vaddiraju Santhisagar
• Srinivasan Akhil
• Probst David
• Chavez Gaxiola Alejo

Classifications

• A61B5/1468 Primary

  using chemical or electrochemical methods, e.g. by polarographic means · CPC title

• A61B5/053

  Measuring electrical impedance or conductance of a portion of the body · CPC title

• A61B5/14532

  for measuring glucose, e.g. by tissue impedance measurement · CPC title

• A61B5/14546

  for measuring analytes not otherwise provided for, e.g. ions, cytochromes · CPC title

• A61B5/1486

  using enzyme electrodes, e.g. with immobilised oxidase · CPC title