Methods and devices for determining sensing device usability
Methods and devices for determining sensing device usability, e.g., for self-monitoring and point of care devices. In one embodiment, the invention is to a method of determining device usability, comprising the steps of providing a device comprising a first electrical pad; a second electrical pad; and a humidity-responsive polymer layer contacting at least a portion of the first and second electrical pads; applying a potential across the first and second electrical pads; measuring an electrical property associated with the humidity-responsive polymer layer; and determining whether the measured electrical property associated with the humidity-responsive polymer layer has exceeded a humidity threshold level associated with the device usability.
1. A method of determining exposure of a glucose test strip to humidity, the method comprising:
inserting said glucose test strip into a glucose meter, said glucose test strip comprising a glucose sensing electrode connected by a first conductive line to a first electrical contact pad and a reference electrode connected by a second conductive line to a second electrical contact pad, wherein a polymer layer responsive to humidity positioned on said glucose test strip contacts at least a portion of said first and said second conductive lines;
applying a potential across said polymer layer;
measuring an electrical property associated with said polymer layer; and
calculating a humidity exposure value from said electrical property,
wherein said polymer layer is selected from the group consisting of a crosslinked polyvinylpyrrolidone (PVP), a crosslinked polymer containing nitrogen heterocyclic groups, and combinations thereof.
2. The method of claim 1 , wherein said applying said potential across said polymer layer occurs prior to applying a blood sample to said glucose test strip.
3. The method of claim 1 , wherein said humidity exposure value is associated with a usability threshold of said glucose test strip.
4. The method of claim 1 , wherein said polymer layer comprises hydronium and hydroxyl ions derived from atmospheric moisture.
5. The method of claim 1 , wherein the electrical property is an open circuit resistance.
6. The method of claim 5 , wherein the humidity exposure value is a mean relative humidity.
7. The method of claim 6 , further comprising correcting a glucose test result using the open circuit resistance and the mean relative humidity.
8. A method of determining exposure of a glucose test strip to humidity, the method comprising:
inserting said glucose test strip into a glucose meter, said glucose test strip comprising a glucose sensing electrode connected by a first conductive line to a first electrical contact pad and a reference electrode connected by a second conductive line to a second electrical contact pad, wherein a polymer layer responsive to humidity positioned on said glucose test strip contacts at least a portion of said first and said second conductive lines;
applying a potential across said polymer layer;
measuring an open circuit resistance associated with said polymer layer;
calculating a mean relative humidity from said open circuit resistance; and
correcting a glucose test result using the open circuit resistance and the mean relative humidity.
9. The method of claim 8 , wherein said applying said potential across said polymer layer occurs prior to applying a blood sample to said glucose test strip.
10. The method of claim 8 , wherein said mean relative humidity is associated with a usability threshold of said glucose test strip.
11. The method of claim 8 , wherein said polymer layer comprises hydronium and hydroxyl ions derived from atmospheric moisture.