The time factor in pressure injury prevention Why “Lower for Longer” is the driving principle behind the performance of an Alternating Pressure surface. When assessing the performance of an active alternating surface, the aim is to achieve lower pressures, for longer times. In independent third party tests, AtmosAir Velaris demonstrated full pressure offloading at the sacral and heel areas for significantly longer times than the other tested surfaces. Find out more on arjo.co