Oura Ring 4

The Oura Ring 4 (Model OA11) represents a significant shift from general wellness toward clinical utility in the wearable space[cite: 1168]. While many rings offer lifestyle insights, the Oura system is uniquely integrated as a cleared data source for the Natural Cycles fertility application (K202897)[cite: 1039, 1083]. Clinical studies involving 40 women demonstrated that the ring's temperature sensors correlate strongly with oral thermometers, allowing it to function as a reliable source for basal body temperature (BBT) monitoring[cite: 1085, 1086]. Beyond fertility, the device employs red and green LEDs for continuous cardiac monitoring and sleep analysis, including heart rate and movement-based sleep staging[cite: 1167]. Its design prioritizes safety with ISO 10993 compliant skin-contact materials[cite: 1167]. Technical performance is robust, with memory capacity to store up to two weeks of data between syncs and a wide operating temperature range[cite: 1167]. However, it is strictly restricted to adult use (18+) and serves as a screening and management tool rather than a standalone diagnostic device[cite: 1167].