Electronic breath actuated in-line droplet delivery device with small volume ampoule and methods of use

An electronically actuated droplet delivery device for delivering a fluid as an ejected stream of droplets to the pulmonary system of a subject, the device comprising:

• a housing;
• a mouthpiece positioned at an airflow exit of the device;
• an air inlet flow element positioned in the airflow at an airflow entrance of the device;
• a small volume drug ampoule disposed in or in fluid communication with the housing, wherein the small volume drug ampoule includes a drug reservoir including an internal flexible membrane separating a first background pressure fluid volume and a second drug volume received by the drug reservoir;
• an electronically actuated ejector mechanism in fluid communication with the drug reservoir and configured to generate the ejected stream of droplets;
• at least one differential pressure sensor positioned within the housing, the at least one differential pressure sensor configured to activate the ejector mechanism upon sensing a pre-determined pressure change within the mouthpiece to thereby generate the ejected stream of droplets;
• the ejector mechanism comprising a piezoelectric actuator and an aperture plate, the aperture plate having a plurality of openings formed through its thickness and the piezoelectric actuator operable to oscillate the aperture plate at a frequency to thereby generate the ejected stream of droplets;
• wherein the housing, air inlet flow element, and mouthpiece are configured to facilitate non-turbulent airflow across an exit side of the aperture plate and to provide sufficient airflow through the housing during use;
• and
• wherein the ejector mechanism is configured to generate the ejected stream of droplets wherein at least about 50% of the droplets have an average ejected droplet diameter of less than about 6 microns, such that at least about 50% of the mass of the ejected stream of droplets is delivered in a respirable range to the pulmonary system of the subject during use.