US Patent 9810623 Quantification of a change in assay

The present invention relates to portable devices for point-of-care diagnostics that can perform measurements on a sample (e.g., blood, serum, saliva, or urine) and relay data to an external device for, e.g., data analysis. The device can comprise a paper-based diagnostic substrate and a base substrate that include electronic circuitry and electronic elements necessary for performing the measurements. The device can also comprise an antenna for near field communication with an external device. Another aspect of the invention relates to methods of using these devices.