Test strip coding and quality measurement
View Patent ↗A test strip and analytical apparatus have pin connections permitting the definition of geographic regions or of particular customers. A test strip made for use in a particular region or for a particular customer will have pin connections matching features of the apparatus made for use in that region or by that customer. Insertion of the strip into the apparatus does not merely turn on the apparatus, but provides the regional or customer coding. Analog switches within the apparatus allow coding of a larger number of distinct regions or customers than would otherwise be possible, all without degrading the quality of the measurements made of the fluid being tested. Conductive paths in the strips permit testing the strips during manufacture so as to detect quality lapses regarding the printing or deposition of the paths.
1. A method for assessing the quality of a conductive layer formed during manufacture of an electrochemical test strip, wherein
the electrochemical test strip is a planar test strip formed from first and second facing substrates, and is elongated for a length in a first dimension parallel to a first axis and having a second dimension corresponding to the width of the strip,
the electrochemical test strip has an electrochemical analysis cell at one axial end and a connection region at the other axial end,
the electrochemical test strip has a patterned conductive layer deposited on the first substrate providing a plurality of conductive regions including
(a) a first conductive region providing a first conductive path from the connector region to the electrochemical analysis cell,
(b) a second conductive region providing a part of a second conductive path, different from the first conductive path, from the connector region to the electrochemical analysis cell,
(c) and a first conductive quality test region that is separate from the first and second conductive regions or coextensive with the one of the conductive regions, with the proviso that when the first conductive quality test region is coextensive with one of the conductive regions it is not a conductive path for analysis;
said method comprising during the manufacture of the test strip the steps of applying first and second probes to the first conductive quality test region; and measuring an electrical signal between the first and second probes to assess the quality of the conductive layer,
wherein the first and second probes are applied to the first conductive quality test region at points that are separated by at least one-fifth the length or width of the test strip.
2. The method of claim 1 , wherein the first conductive quality test region is separate from the first and second conductive regions.
3. The method of claim 2 , wherein the plurality of conductive regions further includes a second conductive quality test region which is separate the first and second conductive regions or coextensive with one of the conductive regions, with the proviso that when the second conductive quality test region is coextensive with one of the conductive regions it is not a conductive path for analysis, further comprising the steps of
applying third and fourth probes to the second conductive quality test region; and
measuring an electrical signal between the third and fourth probes to assess the quality of the conductive layer,
wherein the third and fourth probes are applied to the second conductive quality test region at points that are separated by at least one-fifth the length or width of the test strip.
4. The method of claim 3 , wherein a line between the applied first and second probes is perpendicular to a line between the third and fourth probes.
5. The method of claim 3 wherein a line between the applied first and second probes is parallel to a line between the third and fourth probes.
6. The method of claim 2 , wherein the first conductive quality test region extends across the width of the strip for at least one-fifth the width of the strip.
7. The method of claim 6 , wherein the first conductive quality test region extends along the length the axis for at least one-fifth the length of the strip.
8. The method of claim 2 , wherein the first conductive quality test region extends along the length the axis for at least one-fifth the length of the strip.
9. The method of claim 3 , wherein the second conductive quality test region extends along the length the axis for at least one-fifth the length of the strip.
10. The method of claim 1 , wherein the first conductive quality test region extends across the width of the strip for at least one-fifth the width of the strip.
11. The method of claim 10 , wherein the first conductive quality test region extends along the length the axis for at least one-fifth the length of the strip.
12. The method of claim 1 , wherein the first conductive quality test region extends along the length the axis for at least one-fifth the length of the strip.