A CPAP device and method are provided. The CPAP device includes an inspiratory reservoir, a positive pressure air source, and a pressurizing device. The inspiratory reservoir is fluidically connectable with at least one breathing orifice of a user. The positive pressure air source is fluidically connectable to the inspiratory reservoir. The pressurizing device is movable from a first position to a second position by releasing stored potential energy. During movement to the second position the pressurizing device applies a generally constant pressure to gas contained in the inspiratory reservoir. The pressurizing device is both movable towards the first position and augmentable in stored potential energy by pressure from exhalation air from the user.