Fabrication of multi-sensor arrays

• US 20060076236A1
• Filed: 01/12/2005
• Published: 04/13/2006
• Est. Priority Date: 11/13/2003
• Status: Active Grant

• Current Assignee: DARE MB Incorporated, Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc), MicroCHIPS Inc.
• Inventors: Shah, Rajiv, Soundararajan, Gopikrishnan, Gottlieb, Rebecca K., Wolfe, Katherine T., Pendo, Shaun M., Bruso, Gil
• Granted Patent: US 8,414,489 B2
• Time in Patent Office: Days
• US Class Current: 204/403.10
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• 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 5/412 Detecting or monitoring sepsis
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

The disclosure provides methods for fabricating a long-term analyte sensor for measuring at least one analyte in the body of a user. The analyte sensors made by these methods include a plurality of analyte contacting sensor elements and at least one structure for relaying information to and from the sensor. The analyte sensor so fabricated further includes at least one sensor protection membrane that is controllable in a manner such that sensor elements may be activated (e.g. exposed to the external environment) at different times so as to extend the useful life of the sensor. In illustrative analyte sensors, the analyte is glucose.

Claims

1. A method of making an analyte sensor apparatus comprising the steps of:

providing a substrate layer;

forming a plurality of analyte sensing elements on the substrate layer, wherein the analyte sensor elements are adapted to contact and sense analyte;

forming a lid layer upon at least one of the plurality of analyte sensor elements,

forming at least one analyte sensor membrane over the lid layer, wherein the permeability of the analyte sensor membrane disposed over the lid layer can be controlled so that;

(a) analyte cannot contact at least one of the plurality of analyte sensor elements at a first time point in the use of the analyte sensor apparatus; and

(b) analyte can contact at least one of the plurality of analyte sensor elements at a second time point in the use of the analyte sensor apparatus; and

forming at least one structure operatively coupled to the analyte sensing apparatus for relaying information to and away from the analyte sensing apparatus,

so that an analyte sensor apparatus is made.

2. The method of claim 1, wherein the analyte sensor membrane comprises a metal foil whose permeability is controlled by applying an electric current or an electric potential to the analyte sensor membrane.

3. The method of claim 1, further comprising hermetically coupling the analyte sensor membrane to an aluminum oxide substrate.

4. The method of claim 1, further comprising disposing an analyte modulating layer on the plurality of analyte sensing elements, wherein the analyte modulating layer includes a composition that modulates the diffusion of the analyte therethrough.

5. The method of claim 1, wherein the analyte is glucose or lactate.

6. The method of claim 1, wherein at least one of the plurality of analyte sensor elements comprises an enzyme composition which includes glucose oxidase, glucose dehydrogenase, lactate oxidase, hexokinase or lactate dehydrogenase.

7. The method of claim 1, wherein the lid layer comprises a silicon composition, a ceramic composition, a metal composition, a polymeric composition or a hydro-gel composition.

8. The method of claim 1, further comprising forming an aperture on the lid layer, wherein the aperture so formed on the lid layer provides a passage that can allow analyte to contact at least one of the plurality of analyte sensor elements.

9. The method of claim 8, wherein the aperture is disposed over a cavity fabricated in the lid layer.

10. The method of claim 8, wherein the wherein the analyte sensor membrane comprises a metal foil whose dimensions are thinnest directly over the aperture.

11. The method of claim 1, wherein the lid is fabricated to include recesses and/or projections thereon.

12. The method of claim 1, wherein the lid is attached to the substrate by a solder connection, a infrared reflow connection, a laser reflow connection, an adhesive connection or a ultrasonic connection.

13. The method of claim 1, wherein the analyte sensing device is designed to be implantable in a mammal.

14. The method of 1, wherein the apparatus is made so that at least one of the at least one of the plurality of analyte sensor elements is not disposed in a reservoir or well.

15. A method of making an analyte sensor apparatus for implantation within a mammal comprising the steps of:

providing a substrate layer;

forming a plurality of analyte sensing elements on the substrate layer, wherein the analyte sensor elements are adapted to contact and sense analyte;

forming a lid layer upon at least one of the plurality of analyte sensor elements,

forming a sealed aperture on the lid layer;

forming at least one analyte sensor membrane disposed upon at least one of the plurality of analyte sensor elements in a manner that can reversibly prevent an analyte from contacting the at least one of the plurality of analyte sensor elements, wherein the permeability of the analyte sensor membrane can be controlled to allow an analyte to contact at least one of the plurality of analyte sensor elements; and

forming at least one structure operatively coupled to the analyte sensing apparatus for relaying information to and away from the analyte sensing apparatus,

so that an analyte sensor apparatus is made.

16. The analyte sensing device of claim 15, wherein the analyte sensor membrane comprises a rupturable metallic membrane.

17. The method of claim 15, wherein the lid comprises one or more three dimensional features made by a process which includes chemical etching, reactive ion etching, ion milling, sputtering, evaporation, ion beam assisted deposition, chemical vapor deposition, welding, soldering or brazing.

18. The method of claim 15, wherein the analyte sensor apparatus is made so that the plurality of analyte sensor elements have a plurality of different analyte sensor membranes disposed thereon.

19. The method of claim 18, wherein each of plurality of analyte sensor membranes disposed on the analyte sensor elements is separately controlled.

20. The method of claim 15, wherein the analyte sensing device is made to be a prolonged analyte sensor or a permanent analyte sensor.

21. The method of claim 15, wherein the analyte sensing device is made so that at least two of the analyte sensor elements in the analyte sensing device sense the same analyte.

22. The method of claim 15, wherein the analyte sensing device is made so that at least two of the analyte sensor elements in the analyte sensing device sense different analytes.

23. The method of claim 15, wherein the apparatus is made so that the application of a specific current or potential results in the initiation of reverse plating which removes the analyte sensor membrane so that the aperture in the lid is exposed and results in the exposure of sensing elements over which the aperture is positioned such that new sensing elements that have previously not been active are activated.

24. The method of claim 15, further comprising coupling the apparatus to a multi-lumen catheter in which a first lumen provides connectors for sensor power, data collection, and display, and a second lumen provides connectors which provide power used to change the permeability of the analyte sensor membrane.

25. The method of claim 15, wherein the analyte sensing element is formed to comprise:

a base layer;

a conductive layer disposed upon the base layer wherein the conductive layer includes a working electrode, a reference electrode and a counter electrode;

an analyte sensing layer disposed on the conductive layer, wherein the analyte sensing layer detectably alters the electrical current at the working electrode in the conductive layer in the presence of an analyte;

a protein layer disposed on the analyte sensing layer;

an adhesion promoting layer disposed on the analyte sensing layer or the protein layer, wherein the adhesion promoting layer promotes the adhesion between the analyte sensing layer and an analyte modulating layer disposed on the analyte sensing layer; and

an analyte modulating layer disposed on the analyte sensing layer, wherein the analyte modulating layer modulates the diffusion of the analyte therethrough.