Coupled Events

A coupled event occurs when an oxygen desaturation (SpO2 drop of 3% or more) and a heart rate surge happen within 30 seconds of each other. This temporal coincidence strongly suggests that a single respiratory event triggered both responses, representing a combined cardio-respiratory impact.

Coupled events are clinically significant because they indicate that breathing disruptions are affecting both oxygen levels and the autonomic nervous system simultaneously. This dual impact is more disruptive to sleep quality than either a desaturation or a heart rate surge alone. A high coupled event rate suggests frequent, significant respiratory events that are triggering the full arousal cascade.

AirwayLab tracks coupled events by cross-referencing the timestamps of desaturation events with heart rate surges. The 30-second window accounts for the circulatory delay between a breathing event and its effects on peripheral oxygen and heart rate measurements. Coupled events provide a more specific indicator of respiratory arousals than either metric alone.