The flutter device and expiratory pressures.

Purpose: Flutter therapy uses a handheld instrument that consists of a pipe-like device with a ball in the central core that oscillates during exhalation, providing oscillating positive expiratory pressure. The purpose of this study was to determine the effect of airflow and the incline of the device at the mouth on expiratory pressure and oscillation frequency.

Methods: A Flutter device was attached to a circuit that consisted of a pneumotachograph and a ventilator.