After an ICU stay and diagnosis of diabetes insipidus, John Stallings co-founded Natrium to develop a wearable biosensor that continuously monitors sodium. Its investigational Natrium ONE patch is designed to track sodium in interstitial fluid and show clinicians the current reading, trend, and rate of change rather than relying only on periodic lab draws. Founded in 2024, the founder-led company is developing the device for high-risk clinical settings with co-founder and CTO Andrew Mancini, PhD, the architecture’s lead inventor.