Methods and devices for controlling the impact of short circuit faults on co-planar electrochemical sensors
View Patent ↗Methods and devices are provided for controlling the impact of 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.
1. An electrochemical sensor for measuring concentration of an analyte in a sample fluid, comprising a co-planar electrode system and a sample receiving area, the electrode system comprising a plurality of electrodes each having a distal end at least partially exposed within the sample receiving area and a proximal end comprising a contact pad, each distal end being connected to a corresponding contact pad by a trace lead extending therebetween, each contact pad being configured for electrical connection to a meter configured for use with the electrochemical sensor; wherein first and second electrodes of the plurality of electrodes have respective contact pads laterally spaced apart with a space between them, a third electrode of the plurality of electrodes being located substantially entirely between the first and second electrodes, the contact pad of the third electrode being located entirely between the respective trace leads of the first and second electrodes, the third electrode further comprising a terminal extension extending from the contact pad thereof into the space between the contact pads of the first and second electrodes.
2. The electrochemical sensor of claim 1 , the sensor further comprising a trail located generally between the distal end of the first electrode and the second electrode, wherein a fourth electrode of the plurality of electrodes comprises a second terminal extension extending from the distal end thereof into the trail between the distal end of the first electrode and the second electrode, the second terminal extension extending away from the sample receiving area from a portion of the fourth electrode distal end which is not exposed within the sample receiving area.
3. The sensor of claim 2 wherein at least one of the plurality of electrodes other than the second and third electrodes is disposed substantially between the first electrode and the fourth electrode.