First Design of a Contact Lens for Diagnosis of Dehydration.

Dehydration is a serious medical problem for elderly patients and young children. The most widely used diagnostics are measurements of sodium ion (Na) and potassium ion (K) in blood serum. Dehydration is difficult to diagnose even by trained health care professionals because the body compensates to maintain the appearance of skin. These measurements required a blood draw because specific tests are generally not available for only Na and K. The blood samples are analyzed by an electrolyte panel (EP) or a basic metabolic panel (BMP). Most hospitals limit EP and BMP to one per day to control costs. More frequent measurements of Na and K are needed, especially during rehydration. We designed a dehydration contact lens that can provide the Na and K concentrations as needed or for continuous monitoring. The measurements are obtained from the fluorescent lifetime or wavelength-ratiometric intensities of the Na- and K-sensitive fluorophores. The dehydration contact lens does not contain electronic components and are inexpensive to prepare.