SENSOR WITH LAYERED ELECTRODES

• US 20100191084A1
• Filed: 04/09/2010
• Published: 07/29/2010
• Est. Priority Date: 09/23/2005
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: SHAH, RAJIV, Gottlieb, Rebecca K.
• Granted Patent: US 9,364,177 B2
• Time in Patent Office: Days
• US Class Current: 600/347
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/0017 transmitting optical signals transmission by light H04B10/00
• 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 5/6848 Needles
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: C23C 14/20 on organic substrates
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: G01N 27/307 Disposable laminated or multilayered electrodes G01N27/3272 takes precedence
• CPC Class Codes: G01N 27/3273 Devices therefor, e.g. test element readers, circuitry details not specific to biochemical electrodes G01N33/4875
• CPC Class Codes: G01N 27/4166 measuring a particular property of an electrolyte
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A thin film sensor, such as a glucose sensor, is provided for transcutaneous placement at a selected site within the body of a patient. The sensor includes several sensor layers that include conductive layers and includes a proximal segment defining conductive contacts adapted for electrical connection to a suitable monitor, and a distal segment with sensor electrodes for transcutaneous placement. The sensor electrode layers are disposed generally above each other, for example with the reference electrode above the working electrode and the working electrode above the counter electrode. The electrode layers are separated by dielectric layer.

Claims

1. A flexible analyte sensor comprising:

a base layer;

a first electrode layer disposed on the base layer and including a first electrode;

a first insulative layer disposed on the first electrode layer, wherein said first insulative layer leaves at least a portion of the first electrode exposed;

a second electrode layer disposed on the first insulative layer and including a second electrode; and

a second insulative layer disposed on the second electrode layer, wherein said second insulative layer leaves at least a portion of the second electrode exposed,

wherein the maximum height of the sensor is about 25 microns.

2. The flexible analyte sensor of claim 1, further comprising a third electrode layer disposed on the second insulative layer and including a third electrode.

3. The flexible analyte sensor of claim 2, wherein the second electrode layer is laterally offset from the first electrode layer, and wherein the third electrode layer is laterally offset from the second electrode layer.

4. The flexible analyte sensor of claim 2, wherein the second electrode layer is directly above the first electrode layer, and wherein the third electrode layer is directly above the second electrode layer.

5. The flexible analyte sensor of claim 2, wherein the first, second, and third electrodes are in a staggered configuration.

6. The flexible analyte sensor of claim 2, wherein at least one of the first electrode, second electrode, and third electrode comprises chrome.

7. The flexible analyte sensor of claim 2, wherein one of the electrodes is a counter electrode, one of the electrodes is a reference electrode, and one of the electrodes is a working electrode.

8. The flexible analyte sensor of claim 7, wherein the reference electrode is plated with one or more compounds selected from the group consisting of silver and silver chloride.

9. The flexible analyte sensor of claim 7, wherein at least one of the counter electrode and the working electrode is plated with platinum black.

10. The flexible analyte sensor of claim 2, wherein the first electrode layer further includes a first conductive trace leading from the first electrode to a first conductive pad configured to electrically couple to sensor electronics, the second electrode layer further includes a second conductive trace leading from the second electrode to a second conductive pad configured to electrically couple to sensor electronics, and the third electrode layer further includes a third conductive trace leading from the third electrode to a third conductive pad configured to electrically couple to sensor electronics.

11. The flexible analyte sensor of claim 2, wherein at least one of the base layer, the first insulative layer, the second insulative layer, and the third insulative layer includes polyimide.

12. The flexible analyte sensor of claim 2, further comprising an enzyme layer including glucose oxidase disposed over the first, second, and third electrodes.

13. The flexible analyte sensor of claim 12, wherein the enzyme layer further includes albumin.

14. The flexible analyte sensor of claim 12, wherein the enzyme layer is disposed directly over the first, second, and third electrodes.

15. The flexible analyte sensor of claim 12, further comprising a glucose limiting membrane disposed over the enzyme layer.

16. The flexible analyte sensor of claim 15, wherein the glucose limiting membrane comprises at least one of a silane and polyamine.

17. The flexible analyte sensor of claim 16, wherein the silane is polydimethylsiloxane.

18. The flexible analyte sensor of claim 15, further comprising a hydrophilic membrane over the glucose limiting membrane.

19. The flexible analyte sensor of claim 2, further comprising a third insulative layer disposed on the third electrode layer, wherein said third insulative layer leaves at least a portion of the third electrode exposed.

20. The flexible analyte sensor of claim 19, wherein the first electrode layer is disposed directly on the base layer without any intervening layers, the first insulative layer is disposed directly on the first electrode layer without any intervening layers, the second electrode layer is disposed directly on the first insulative layer without any intervening layers, the second insulative layer is disposed directly on the second electrode layer without any intervening layers, the third electrode layer is disposed directly on the second insulative layer without any intervening layers, and the third insulative layer is disposed directly on the third electrode layer without any intervening layers.

21. The flexible analyte sensor of claim 20, wherein the second electrode layer is directly above the first electrode layer, the third electrode layer is directly above the second electrode layer, and the first, second and third electrodes are in a staggered configuration.

22. The flexible analyte sensor of claim 1, wherein the first electrode layer is disposed directly on the base layer without any intervening layers.

23. The flexible analyte sensor of claim 1, wherein the first insulative layer is disposed directly on the first electrode layer without any intervening layers.

24. The flexible analyte sensor of claim 1, wherein the second electrode layer is disposed directly on the first insulative layer without any intervening layers.

25. The flexible analyte sensor of claim 1, wherein the second insulative layer is disposed directly on the second electrode layer without any intervening layers.

26. The flexible analyte sensor of claim 1, wherein the height of each electrode layer is less than about 5000 angstroms and each insulative layer is about 5 microns.

27. The flexible analyte sensor of claim 1, wherein at least one of the first electrode and the second electrode comprises one or more compounds selected from the group consisting of gold and chrome.

28. The flexible analyte sensor of claim 1, wherein the flexible analyte sensor is configured to sense a current representative of the amount of glucose in the body of a patient.

29. An analyte monitoring system comprising:

(a) a flexible analyte sensor comprising;

a base layer;

a first electrode layer disposed on the base layer and including a first electrode;

a first insulative layer disposed on the first electrode layer, wherein said first insulative layer leaves at least a portion of the first electrode exposed;

a second electrode layer disposed on the first insulative layer and including a second electrode;

a second insulative layer disposed on the second electrode layer, wherein said second insulative layer leaves at least a portion of the second electrode exposed; and

a third electrode layer disposed on the second insulative layer and including a third electrode,

wherein the first electrode layer further includes a first conductive trace leading from the first electrode to a first conductive pad configured to electrically couple to sensor electronics, the second electrode layer further includes a second conductive trace leading from the second electrode to a second conductive pad configured to electrically couple to sensor electronics, the third electrode layer further includes a third conductive trace leading from the third electrode to a third conductive pad configured to electrically couple to sensor electronics, and the maximum height of the sensor is about 25 microns;

(b) sensor electronics electrically connected to the first, second, and third conductive pads; and

(c) an analyte monitor, wherein the sensor electronics and the analyte monitor are configured to communicate with one another.

30. The analyte monitoring system of claim 29, wherein the sensor electronics and the analyte monitor are configured to communicate wirelessly with one another.

31. The analyte monitoring system of claim 30, wherein the type of wireless communication is selected from the group consisting of radio frequency and infrared.

32. The analyte monitoring system of claim 30, wherein the type of wireless communication is selected from the group consisting of single frequency communication, spread spectrum communication, adaptive frequency selection, and frequency hopping communication.

33. An analyte monitoring system comprising:

(a) a flexible analyte sensor comprising;

a base layer;

a first electrode layer disposed on the base layer and including a first electrode;

a first insulative layer disposed on the first electrode layer, wherein said first insulative layer leaves at least a portion of the first electrode exposed;

a second electrode layer disposed on the first insulative layer and including a second electrode;

a second insulative layer disposed on the second electrode layer, wherein said second insulative layer leaves at least a portion of the second electrode exposed;

a third electrode layer disposed on the second insulative layer and including a third electrode;

an enzyme layer including glucose oxidase disposed over the first, second, and third electrodes; and

a glucose limiting membrane disposed over the enzyme layer,

wherein the maximum height of the sensor is about 25 microns;

(b) sensor electronics in electrical communication with the first, second and third electrodes; and

(c) an analyte monitor, wherein the sensor electronics and the analyte monitor are configured to communicate with one another.

34. The analyte monitoring system of claim 33, wherein the sensor electronics and the analyte monitor are configured to communicate wirelessly with one another.

35. The analyte monitoring system of claim 34, wherein the type of wireless communication is selected from the group consisting of radio frequency and infrared.

36. The analyte monitoring system of claim 34, wherein the type of wireless communication is selected from the group consisting of single frequency communication, spread spectrum communication, adaptive frequency selection, and frequency hopping communication.

37. An analyte monitoring system comprising:

(a) a flexible analyte sensor comprising;

a base layer;

a first electrode layer disposed on the base layer and including a first electrode;

a first insulative layer disposed on the first electrode layer, wherein said first insulative layer leaves at least a portion of the first electrode exposed;

a second electrode layer disposed on the first insulative layer and including a second electrode;

a second insulative layer disposed on the second electrode layer, wherein said second insulative layer leaves at least a portion of the second electrode exposed;

a third electrode layer disposed on the second insulative layer and including a third electrode; and

a third insulative layer disposed on the third electrode layer, wherein said third insulative layer leaves at least a portion of the third electrode exposed,

wherein the first electrode layer is disposed directly on the base layer without any intervening layers, the first insulative layer is disposed directly on the first electrode layer without any intervening layers, the second electrode layer is disposed directly on the first insulative layer without any intervening layers, the second insulative layer is disposed directly on the second electrode layer without any intervening layers, the third electrode layer is disposed directly on the second insulative layer without any intervening layers, and the third insulative layer is disposed directly on the third electrode layer without any intervening layers; and

wherein the second electrode layer is directly above the first electrode layer, the third electrode layer is directly above the second electrode layer, the first, second, and third electrodes are in a staggered configuration, and the maximum height of the sensor is about 25 microns;

(b) sensor electronics in electrical communication with the first, second, and third electrodes; and

(c) an analyte monitor, wherein the sensor electronics and the analyte monitor are configured to communicate with one another.

38. The analyte monitoring system of claim 37, wherein the sensor electronics and the analyte monitor are configured to communicate wirelessly with one another.

39. A flexible analyte sensor comprising:

a base layer;

a first electrode layer disposed on the base layer and including a first electrode;

a first insulative layer disposed on the first electrode layer, wherein said first insulative layer leaves at least a portion of the first electrode exposed;

a second electrode layer disposed on the first insulative layer and including a second electrode;

a second insulative layer disposed on the second electrode layer, wherein said second insulative layer leaves at least a portion of the second electrode exposed;

an enzyme layer disposed directly over said exposed portions of the electrodes;

a glucose limiting membrane disposed directly over said enzyme layer; and

a hydrophilic membrane disposed directly over the glucose limiting membrane,

wherein the maximum height of the sensor is about 25 microns.

40. The flexible analyte sensor of claim 39, wherein at least one of the first and second electrodes comprises chrome, and the glucose limiting membrane comprises polyamine.

41. The flexible analyte sensor of claim 39, wherein the second electrode layer is laterally offset from the first electrode layer.

42. The flexible analyte sensor of claim 39, further including:

a third electrode layer disposed on the second insulative layer and including a third electrode; and

a third insulative layer disposed on the third electrode layer, wherein said third insulative layer leaves at least a portion of the third electrode exposed.

43. An analyte monitoring system comprising:

(a) a flexible analyte sensor comprising;

a base layer;

a first electrode layer disposed on the base layer and including a first electrode;

a first insulative layer disposed on the first electrode layer, wherein said first insulative layer leaves at least a portion of the first electrode exposed;

a second electrode layer disposed on the first insulative layer and including a second electrode;

a second insulative layer disposed on the second electrode layer, wherein said second insulative layer leaves at least a portion of the second electrode exposed;

an enzyme layer disposed directly over said exposed portions of the electrodes;

a glucose limiting membrane disposed directly over said enzyme layer; and

a hydrophilic membrane disposed directly over the glucose limiting membrane,

wherein the second electrode layer is directly above the first electrode layer, the first and second electrodes are in a staggered configuration, and the maximum height of the sensor is about 25 microns;

(b) sensor electronics in electrical communication with the first and second electrodes; and

(c) an analyte monitor, wherein the sensor electronics and the analyte monitor are configured to communicate wirelessly with one another.

44. The analyte monitoring system of claim 43, wherein at least one of the first and second electrodes comprises chrome, and the glucose limiting membrane comprises polyamine.