Method and apparatus for assisting expulsional movement of pulmonary secretions via supramaximal flows

An apparatus for assisting the movement of pulmonary secretions towards the outlet of a subject's respiratory tract by inducing supramaximal flows in a subject's respiratory tract during the subject's exhalation, the apparatus comprising means for moving the secretions toward the outlet of the subject's respiratory tract, said means including:

• a) a valve having an opening time to a fully opened condition of not more than 10 milliseconds against a unidirectional expiratory flow of the subject, the valve having an inlet and an outlet, the inlet being adapted to be connected to the outlet of the respiratory tract of the subject;
• b) pressure sensing means for generating a first signal indicative of a positive pressure in the upper part of the respiratory tract;
• c) means for generating a second signal corresponding to a substantial collapse or near-collapse of the respiratory tract;
• d) valve opening control means including means for establishing a predetermined pressure level and operative to open the valve in response to said first signal from said pressure sensing means indicating that the sensed pressure reaches or exceeds said predetermined level;
• and
• e) valve closing control means operative to close the valve in response to said second signal corresponding to a substantial collapse or near-collapse of the respiratory tract, said opening of said valve inducing a cycle of events in the respiratory tract including a supramaximal expiratory flow and a resulting near-collapse of said tract followed by a closing of said valve, said cycle having a duration considerably shorter than an exhalation time of the subject, said valve opening and valve closing control means being operative, synchronously with said cycle, to repetitively open and close said valve a plurality of times during a single exhalation of the subject, said repetitive opening and closing of said valve thus creating a series of said supramaximal flows which is effective to move secretions towards the outlet of the subject's respiratory tract.