ANALYTE SENSOR APPARATUSES HAVING IMPROVED ELECTRODE CONFIGURATIONS AND METHODS FOR MAKING AND USING THEM

• US 20110230735A1
• Filed: 03/14/2011
• Published: 09/22/2011
• Est. Priority Date: 03/16/2010
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Larson, Eric Allan, Kantak, Ameya S., Pesantez, Daniel E., Xi, Dongjuan, Wolfe, Katherine T., Shah, Rajiv, Chiu, Chia-Hung
• Granted Patent: US 10,448,872 B2
• Time in Patent Office: Days
• US Class Current: 600/309
• 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 5/14542 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 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/6848 Needles

Abstract

Embodiments of the invention provide analyte sensors having optimized elements and/or configurations of elements as well as methods for making and using such sensors. Typical embodiments of the invention include glucose sensors used in the management of diabetes.

Claims

1. An analyte sensor comprising:

a plurality of sensor wires having a first end and second end and each arranged in a substantially common orientation, the plurality of sensor wires being electrically conductive and including;

a first sensor wire substantially covered by a first electrically insulating cover, wherein an aperture in the first electrically insulating cover defines a working electrode area;

a second sensor wire substantially covered by a second electrically insulating cover, wherein an aperture in the second electrically insulating cover defines a reference electrode area; and

a third sensor wire substantially covered by a third electrically insulating cover, wherein an aperture in the third electrically insulating cover defines a counter electrode area.

2. The analyte sensor of claim 1 wherein the plurality of sensor wires further includes a fourth sensor wire substantially covered by a fourth electrically insulating cover, wherein an aperture in the fourth electrically insulating cover defines a second working electrode.

3. The analyte sensor of claim 1, wherein the plurality of sensor wires are arranged in a ribbon wire configuration.

4. The analyte sensor of claim 1, wherein the plurality of sensor wires are arranged in a bundled configuration.

5. The analyte sensor of claim 1, wherein the plurality of sensor wires are arranged in a stacked configuration.

6. The analyte sensor of claim 1, wherein the plurality of sensor wires coil around a core cylindrical material.

7. The analyte sensor of claim 6, wherein the core cylindrical material is a material selected from the group consisting of a coated polymer, a hydrogel and a shape memory alloy.

8. The analyte sensor of claim 1, wherein the first and third sensor wires each comprise a material independently selected from the group consisting of platinum, iridium, iridium oxide, and palladium.

9. The analyte sensor of claim 1, wherein the second sensor wire comprises a material selected from the group consisting of silver, silver chloride and a combination of silver and silver chloride.

10. The analyte sensor of claim 1 wherein the first electrically insulating cover, second electrically insulating cover, and third electrically insulating cover each comprise a material independently selected from the group consisting of PTFE (polytetrafluoroethylene), ETFE (ethylene tetrafluoroethylene), FEP (fluorinated ethylene propylene), and PFA (perfluoroalkoxy).

11. The analyte sensor of claim 1 wherein at least one of the plurality of sensor wires comprises a shape memory alloy.

12. The analyte sensor of claim 1, wherein the portion of the first sensor wire exposed at the working electrode area is coated with an electrode coating selected from the group consisting of platinum black, porous platinum, iridium, iridium oxide, and polypyrrole.

13. The analyte sensor of claim 1, wherein the portion of the first sensor wire exposed at the working electrode area has been modified to increase surface area.

14. The analyte sensor of claim 13, wherein the portion of the first sensor wire exposed at the working electrode area has been at least partially coated with one or more components selected from the group consisting of porous metals and porous polymers.

15. The analyte sensor of claim 1, wherein the portion of the first wire exposed at the working electrode area is coated with an analyte sensing layer comprising glucose oxidase.

16. The analyte sensor of claim 15, wherein the analyte sensing layer is coated with an analyte modulating layer comprising polydimethyl siloxane (PDMS).

17. The analyte sensor of claim 16, wherein the analyte sensing layer is coated with an adhesion promoting layer that is under the analyte modulating layer, wherein the adhesion promoting layer comprises a silane compound.

18. The analyte sensor of claim 1, wherein at least one of the plurality of sensor wires has a second aperture in its electrically insulating cover defining a second electrode area.

19. The analyte sensor of claim 1, wherein the plurality of sensor wires has a first side and a second side opposite to the first side, and wherein the working electrode area is on the first side and the counter electrode area and reference electrode areas are on the second side.

20. The analyte sensor of claim 1, wherein each of the plurality of sensor wires has a tip at the first end of the plurality of sensor wires, wherein the tips are not covered by the electrically insulating covers, and wherein the tips are coated by a tipping layer.

21. The analyte sensor of claim 20, wherein the tipping layer comprises a poly(p-xylylene) polymer.

22. The analyte sensor of claim 1, wherein each of the plurality of sensor wires is exposed from the electrically insulating cover at a portion defining a contact in electrical communication with the electrode area on that wire, wherein the contacts are substantially near or at the second end of the plurality of sensor wires and the electrode areas are substantially near or at the first end of the plurality of sensor wires.

23. A sensor set comprising:

a mounting base adapted to be placed on to the skin of a patient, the mounting base including an opening and a connector portion; and

the analyte sensor of claim 1, housed in the mounting base, wherein near or at its second end each of the plurality of sensor wires is exposed from its electrically insulating cover to define a contact in electrical communication with the connector portion of the mounting base;

wherein at least the first end of the analyte sensor extends out of the opening in the mounting base substantially at an angle of ninety degrees from the base.

24. The sensor set of claim 23 further comprising a cannula substantially covering the portion of the analyte sensor extending out of the mounting base.

25. The sensor set of claim 23 further comprising a transmitter connectable to the mounting base at the connector portion and adapted to receive signals from the analyte sensor.

26. The sensor set of claim 25, wherein the transmitter includes a transmitter recess and transmitter pins inside the recess to electrically connect the transmitter to the analyte sensor when the connecting portion of the mounting base is inserted into the transmitter recess.

27. The sensor set of claim 26, wherein the connector portion of the mounting base includes conductive pins in electric communication with the electrode areas on the analyte sensor, wherein the conductive pins adapted to connect to the transmitter pins.

28. The sensor set of claim 27, wherein each of the plurality of sensor wires is exposed from the electrically insulating cover at a portion defining a contact in electrical communication with the electrode area on that wire, wherein the contacts are substantially near or at the second end of the plurality of sensor wires and the electrode areas are substantially near or at the first end of the plurality of sensor wires, and wherein the contacts are adapted to electrically connect to the conductive pins.

29. The sensor set of claim 27, wherein the mounting base further includes a metal insert adapted to pierce the electrically insulating cover of each of the plurality of electrically conductive wires when the analyte sensor is housed in the mounting base such that the electrode areas are in electronic communication with the metal insert, wherein the metal insert is adapted to electrically connect to the conductive pins.

30. A method for avoiding tissue trauma at a sensor insertion site, comprising:

inserting an analyte sensor into the skin of a patient, wherein the analyte sensor includes;

a plurality of sensor wires having a first end and second end and each arranged in a substantially common orientation, the plurality of sensor wires being electrically conductive and including;

a first sensor wire substantially covered by a first electrically insulating cover, wherein an aperture in the first electrically insulating cover defines a working electrode area;

a second sensor wire substantially covered by a second electrically insulating cover, wherein an aperture in the second electrically insulating cover defines a reference electrode area; and

a third sensor wire substantially covered by a third electrically insulating cover, wherein an aperture in the third electrically insulating cover defines a counter electrode area.

31. The method of claim 30, wherein the inserting of the analyte sensor includes:

inserting a needle into the skin of the patient, wherein the needle is in contact with the analyte sensor; and

removing the needle from the skin of the patient such that the sensor remains in the skin of the patient.

32. The method of claim 30, wherein the inserting of the analyte sensor is accomplished without a needle.

33. The method of claim 30, further comprising:

placing a mounting base onto the skin of the patient, the mounting base including an opening and a connector portion, wherein the analyte sensor is housed in the mounting base, wherein at least the first end of the analyte sensor extends out of the opening in the mounting base into the skin of the patient substantially at an angle of ninety degrees from the base.