What is the term used for the interval from when oxygen supply is interrupted to when useful function is lost?

The correct term for the interval from when oxygen supply is interrupted to when useful function is lost is "Time of useful consciousness." This concept is vital in aerospace physiology, particularly concerning the effects of hypoxia, which can occur at high altitudes where the availability of oxygen is significantly reduced.

During this time, an individual is still capable of performing tasks but may begin to experience the early effects of hypoxia. The duration varies depending on several factors, including altitude, individual physiology, and acclimatization. It emphasizes the importance of recognizing the onset of hypoxia and the limited time available for corrective actions, such as using supplemental oxygen or descending to a lower altitude where oxygen levels are sufficient.

Understanding this interval allows pilots and personnel to make informed decisions and maintain operational safety under conditions of reduced oxygen availability.