Which of the following is a feature of the cough assist device?

The cough assist device is designed to help individuals who have difficulty clearing secretions from their airways, often due to conditions like neuromuscular diseases. The key feature of this device is that it utilizes alternating positive and negative pressure to effectively mimic the natural mechanics of a cough.

When the device applies positive pressure, it encourages airflow into the lungs, expanding them and allowing for air to be filled. Following this, it switches to negative pressure, which helps to create a forceful outflow of air that resembles a cough. This dual action effectively assists in expelling mucus and other secretions from the respiratory tract, making it beneficial for patients who otherwise struggle to generate an effective cough reflex.

Other options presented do not represent features of a cough assist device. The notion of inducing a strong voluntary cough is not applicable because the cough assist device works mechanically rather than relying on voluntary effort. High-frequency chest oscillation refers to a different therapeutic technique often used in airway clearance, not the mechanism of action in cough assist devices. Continuous positive airway pressure (CPAP) is a separate treatment modality used primarily to maintain open airways in conditions such as sleep apnea and does not involve the mechanism of alternating pressures used in cough assistance.