The Pneumatic Pulsed Oscillatory Phlegm expectoration device is a medical device that is used to help patients suffering from respiratory diseases to get rid of phlegm. It stimulates the patient's airway by generating pulsed oscillations of airflow, which loosens and expels phlegm from the body, thus improving airway patency. This device usually consists of a main unit and corresponding accessories such as an endotracheal tube, mask, etc. It is a medical tool rather than a medical device. It is a medical tool, not a book.