The SleepImage Ring is also a single-sensor wireless sleep test with FDA clearance. Designed with a rubbery material, the device is slipped on a finger before bed.

It contains a photoplethysmogram sensor that detects blood volume changes in vascular tissue, heart rate, and oxygen saturation. The SleepImage software uses its own sleep-disordered breathing measurement system, the “SleepImage Apnea Hypopnea Index” or “sAHI,” an automated scoring index that adheres to the American Academy of Sleep Medicine’s scoring guidelines.