LAYERED SENSOR FOR DETERMINING AN ANALYTE CONCENTRATION

• US 20090156920A1
• Filed: 06/19/2008
• Published: 06/18/2009
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Kotzan, Holger, Bainczyk, Gregor
• Granted Patent: US 8,326,393 B2
• Time in Patent Office: Days
• US Class Current: 600/347
• 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: C12Q 1/006 for glucose
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 29/49002 Electrical device making
• 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

An implantable sensor is provide which can be used for determining a concentration of at least one analyte in a medium, in particular a body tissue and/or a body fluid. The implantable sensor has a layered construction with at least one insulating carrier substrate and at least two electrodes which are arranged in at least two different layer planes of the implantable sensor and are electrically isolated from one another by the at least one insulating carrier substrate. The electrodes have electrode areas which face the medium when the sensor has been implanted, and are in contact with the medium over a large area and substantially uniformly, directly or via a generally analyte-permeable membrane layer.

Claims

1. An implantable sensor for determining a concentration of at least one analyte in a body tissue or a body fluid, the implantable sensor having a layered construction comprising at least one insulating carrier substrate and at least two electrodes which are arranged in at least two different layer planes of the implantable sensor, are electrically isolated from one another by the at least one insulating carrier substrate and have electrode areas, the electrode areas facing the medium when the sensor has been implanted, and being in contact directly or via a generally analyte-permeable membrane layer with the body tissue or body fluid over a large area and substantially uniformly, the implantable sensor further comprising at least two electrode contact layers in electrical contact respectively with the at least two electrodes, wherein the at least one insulating carrier substrate has a width, and the at least two electrodes or the at least two electrode contact layers extending over substantially the entire width of the at least one insulating carrier substrate.

2. The implantable sensor according to claim 1 wherein the at least two electrodes comprise at least one working electrode and at least one further electrode comprising at least one of a counter electrode and a reference electrode, the at least one working electrode and the at least one further electrode being arranged in different planes of the layered construction.

3. The implantable sensor according to claim 2 wherein the at least one further electrode comprises a common electrode comprising a counter electrode and a reference electrode.

4. The implantable sensor according to claim 1 wherein the at least two electrode contact layers are covered at least partly with respect to the body tissue or body fluid by at least one insulator layer.

5. The implantable sensor according to claim 4 wherein the at least one insulator layer comprises a self-adhesive film layer.

6. The implantable sensor according to claim 1 wherein the at least one membrane layer comprises a polyurethane.

7. The implantable sensor according to claim 1 wherein the at least one carrier substrate is generally analyte-impermeable.

8. The implantable sensor according to claim 1 wherein the at least one carrier substrate comprises an insulating polymer.

9. The implantable sensor according to claim 7 wherein the insulating polymer comprises a polyester.

10. The implantable sensor according to claim 1 further comprising an insertion tip configured for inserting the implantable sensor into the body tissue or body fluid.

11. The implantable sensor according to claim 10 wherein the at least one insulating carrier substrate and/or the implantable sensor has a width B and a height H, the ratio H/B or the reciprocal thereof defining an aspect ratio k, the aspect ratio k being at least about 0.3.

12. The implantable sensor according to claim 11 wherein aspect ratio k is at least about 0.5.

13. The implantable sensor according to claim 11 wherein aspect ratio k is at least about 0.9.

14. The implantable sensor according to claim 1 wherein the layered construction, comprises a stepped layer construction comprising at least two insulating carrier substrates forming at least one step.

15. The implantable sensor according to claim 14 wherein one of the at least two electrically isolated electrodes is arranged in the plane of the at least one step, and wherein said one electrode and another of the at least two electrically isolated electrodes comprise generally parallel, equidirectional electrode areas.

16. The implantable sensor according to claim 14, the stepped construction comprising two steps each comprising equidirectional electrodes arranged in the planes of the respective two steps.

17. The implantable sensor according to claim 14 wherein at least one further electrode is provided which is arranged on a side of the at least one carrier substrate that is remote from the at least one step, and is oriented with its electrode area opposite to the step.

18. The implantable sensor according to claim 1 wherein at least two electrodes are arranged on opposite sides of the at least one carrier substrate and have oppositely directed electrode areas facing the body tissue or body fluid.

19. The implantable sensor according to claim 1 wherein a back-to-back construction, having at least one carrier substrate provided between a first electrode contact layer and a second electrode contact layer, at least one first electrode being provided on that side of the first electrode contact layer which is remote from the at least one carrier substrate, and at least one second electrode being provided on that side of the second electrode contact layer which is remote from the carrier substrate.

20. A device for determining a concentration of at least one-analyte in a body tissue or a body fluid, comprising at least one implantable sensor according to claim 2, the further electrode comprising at least one counter electrode and at least one reference electrode, and further comprising at least one voltage measuring device for measuring a voltage between the at least one working electrode and the at least one reference electrode of the implantable sensor.

21. The device according, to claim 20, further comprising at least one current measuring device for measuring a current between the at least one counter electrode and the at least one working electrode of the implantable sensor.

22. The device according to claim 20 wherein the device is configured for continuously determining a concentration of at least one analyte in the body tissue or body fluid.

23. A method for producing an implantable sensor for determining an analyte concentration in a body tissue or a body fluid, the method comprising the steps of:

applying a first metal layer substantially over a first plane of a carrier film and a second metal layer substantially over a second plane of the carrier film, wherein the first and second metal layers comprise first and second electrode contact layers and the first and second planes are spaced apart on the carrier film, the carrier film comprising an insulating material;

providing first and second electrodes on the respective first and second electrode contact layers; and

cutting the carrier film into a plurality of strips, wherein each strip comprises an implantable sensor.

24. The method according to claim 23 wherein the first and second metal layers are applied according to a method selected from the group consisting of:

a lamination method, a reel-to-reel film method, a. PVD method, a CVD method, and a wet-chemical coating method.

25. The method according to claim 23, wherein at least one first carrier film is coated on both sides with electrode contact layers, at least one first electrode system being applied to one of the two electrode contact layers on the side remote from the carrier film, and at least one second electrode system being applied to the other of the two electrode contact layers on the side remote from the carrier film.

26. The method according to claim 25 wherein a second carrier film is coated on one side with a third electrode contact layer, a third electrode system being applied to the third electrode contact layer, the second carrier film being applied, with the side remote from the third electrode contact layer, to the first carrier film surrounded on both sides with electrode contact layers, in such a way that at least one step is formed.

27. The method according to claim 23 further comprising applying at least one insulator layer at least partially over each metal layer.