Methods and devices for controlling the impact of short circuit faults on co-planar electrochemical sensors

• US 20060278538A1
• Filed: 06/13/2006
• Published: 12/14/2006
• Est. Priority Date: 06/14/2005
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Groll, Henning, Burke, David W.
• Granted Patent: US 7,905,997 B2
• Time in Patent Office: Days
• US Class Current: 205/777.500
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52

Abstract

Methods and devices are provided for controlling the impact undesirable short circuits between non-adjacent but critically matched pairs of electrodes in a co-planar electrochemical sensor. In one embodiment, the size and/or shape of at least one electrode is configured to induce a short circuit between electrode pairs for which connectivity is pre-set to be measured by a meter in order to indicate a short circuit between a different pair for which such connectivity is not pre-set to be measured. In another embodiment, the surface area of one or more electrodes, other than the working electrode, which are designed to be exposed to a sample fluid is significantly limited in relation to the surface area of the working electrode that is exposed to the sample fluid.

Claims

1. An electrochemical sensor for measuring concentration of an analyte in a sample fluid, said sensor adapted for being received and electrically connected to a meter, said sensor comprising a co-planar electrode system having a working electrode, a plurality of other electrodes and a sample receiving area, first and second electrodes of said other electrodes being configured each to be electrically isolated from the other and from said working electrode, said first electrode comprising a distal end at least a portion of which is exposed within said sample receiving area, said second electrode comprising an extension at one end thereof, said extension interrupting a space or trail on said sensor between said first electrode and said working electrode proximate said one end, said extension being configured for electrical connectivity to an electrical short between said first electrode and said working electrode occurring in said space or trail, said electrical short comprising any electrical connectivity between said first electrode and said working electrode that occurs despite the desired isolated electrode configuration of said sensor.

2. The sensor of claim 1, wherein said meter is configured to verify the electrical isolation between said working electrode and said second electrode and between said first electrode and said electrode when said sensor is electrically connected to said meter, and is not configured to verify the electrical isolation between said working electrode and said first electrode.

3. The sensor of claim 1, wherein said meter is configured to verify the electrical isolation between said working electrode and said second electrode, or between said first electrode and said second electrode, when said sensor is electrically connected to said meter, and is not configured to verify the electrical isolation between said working electrode and said first electrode.

4. The sensor of claim 1, further comprising a third electrode of said plurality of electrodes having a second extension at an end thereof generally opposite on said sensor from said one end of said second electrode, said second extension interrupting a second space or trail between said working electrode and said first electrode proximate said one end of said third electrode, said second extension being configured for electrical connectivity to an electrical short between said first electrode and said working electrode occurring in said second space or trail, said electrical short comprising any electrical connectivity between said first electrode and said working electrode that occurs despite the desired isolated electrode configuration of said sensor.

5. A method for indirectly verifying electrical isolation between non-adjacent electrodes of an electrochemical sensor having a co-planar electrode system, the method comprising the steps of:

providing a working electrode and at leas first and second electrodes on said sensor, at least a portion of said working electrode and said first electrode being exposed in a sample receiving area of said sensor, said second electrode being provided having at least one end configured to extend substantially between said working electrode and said first electrode proximate said one end, each of said first electrode second electrode and working electrode being intended to be electrically isolated each from the other;

inserting said sensor into a meter configured to receive and electrically connect with said sensor;

using said meter to measure electrical connectivity between said working electrode and said second electrode;

using said meter to measure electrical connectivity between said first electrode and said second electrode; and

displaying an error message on said meter if electrical connectivity is measured between said working electrode and said second electrodes or between said first electrode and said second electrode;

wherein any electrical connectivity between said first electrode and said working electrode must also result in electrical connectivity between said first electrode and said second electrode proximate said one end.

6. An electrochemical sensor for measuring concentration of an analyte in a sample fluid, said sensor adapted for being received and electrically connected to a meter, said sensor comprising a co-planar electrode system having a sample receiving area, a working electrode at least a portion of which is exposed within said receiving area and at least one other electrode, said at least one other electrode being configured to be electrically isolated from said working electrode and comprising a distal end at least a portion of which is exposed within said sample receiving area the surface area of said portion of said at least one other electrode being no more than about 50% of the surface area of said portion said working electrodes.

7. The sensor of claim 6, the surface area of said portion of said at least one other electrode being no more than about 10% of the surface area of said portion of said working electrode.

8. A method for controlling the affect of a short circuit between critically matched electrodes in an electrochemical sensor having a co-planar electrode system the method comprising the steps of:

providing an electrochemical sensor having a sample receiving area, a working electrode having at least a portion exposed within said sample receiving area, and at least one other electrode intended to be electrically isolated from said working electrode and comprising a distal end having at least a portion thereof exposed within said sample receiving area;

providing said at least one other electrode with a surface area of said portion of said distal end thereof being no more than about 50% of the surface area of said portion of said working electrode.

9. The method of claim 8, wherein said portion of said distal end of said at least one other electrode is provided with a surface area being no more than about 10% of the surface area of said portion of said working electrode.