Just cleared by the FDA late last month, this new ingestible sensor from California-based Proteus Digital Health is about the size of a grain of sand and can be integrated into an inert pill or medicine. Once in the stomach, it is powered solely by contact with stomach fluid and communicates a unique signal that identifies the timing of ingestion. This information is transferred through the user’s body tissue to a battery-operated patch worn on the skin that detects the signal along with physiological and behavioral metrics such as heart rate, body position and activity. That data, in turn, gets relayed by the patch to a mobile application, where it can be made accessible by caregivers and clinicians.