Remote exercise-induced sweat chloride measurements using a wearable microfluidic sticker in cystic fibrosis patients.

Sweat parameters such as volume and chloride concentration may offer invaluable clinical insights for people with CF (PwCF). Pilocarpine-induced sweat collection for chloridometry measurement is the gold-standard for sweat chloride, but this technique is cumbersome and not suitable for remote settings. We have previously reported the utility of a skin-interfaced microfluidic device (CF Patch) in conjunction with a smartphone image processing platform that enables real-time measurement of sweating rates and sodium chloride loss in laboratory and remote settings. Here we conducted clinical studies characterizing the accuracy of the CF Patch compared to pilocarpine-induced sweat measurements using chloridometry and tested the feasibility of exercise-induced sweat chloride measurements in PwCF. The CF Patch demonstrated strong correlations compared to sweat chloride measured by chloridometry across clinic and remote settings and detected greater day-to-day sweat chloride variability in PwCF on CFTR modulators than healthy volunteers. These findings demonstrate that the CF Patch is suitable as a remote management device capable of measuring chloride concentrations and offers the potential of monitoring the efficacy of CF medication regimens.