BodiMetrics is an American health technology company that makes portable monitoring devices and the CIRCUL line of smart rings. The rings are worn on a finger and focus on continuous blood oxygen, heart rate, activity and sleep measurements for personal wellness and remote monitoring.

How it works
Red and infrared light pass into the finger, and a detector measures how much light returns as blood volume and oxygenation change. Motion and temperature sensors add context about activity and sleep. The app turns these signals into oxygen levels, pulse, sleep stages, exercise records and alerts when readings cross selected limits.

Key considerations
Ring fit and hand movement can affect optical readings, especially during activity. Some blood oxygen functions have regulatory clearance, but that does not make every score or insight a medical measurement. Features and claims also differ across CIRCUL models.