Ultrasonic breath actuated respiratory droplet delivery device and methods of use

A droplet delivery device comprising:

• a mouthpiece positioned at an airflow exit of the device, the mouthpiece comprising one or more air flow entrance ports, an airflow exit opening, an electronically actuated ejector, an ejection chamber, and a fluid transport mating extension;
• a fluid cartridge including a volume of fluid and at least one self-sealing stopper, the fluid cartridge disposed within or in fluid communication with the mouthpiece;
• a body housing comprising a power source and control board;
• and
• at least one pressure sensor positioned within the mouthpiece or positioned within the housing and in fluid communication with the mouthpiece, the at least one pressure sensor operably coupled to the ejector to generate an ejected stream of droplets upon sensing a pre-determined pressure change within the mouthpiece;
• wherein the electronically actuated ejector is in fluid communication with the volume of fluid at a fluid cartridge side of the ejector, the ejector 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 ejection chamber is located adjacent the ejector on the fluid cartridge side of the ejector;
• wherein the fluid transport mating extension interfaces with or extends through the self-sealing stopper to create fluid communication between the fluid cartridge and the ejector;
• wherein the fluid transport mating extension comprises a wicking element extending through the self-sealing stopper into the volume of fluid and configured to draw liquid from the fluid cartridge toward the ejector by capillary action;
• wherein the mouthpiece further comprises at least one vent opening positioned on a fluid side of the aperture plate adjacent the ejector;
• and
• wherein the at least one vent opening is configured to release air displaced by liquid transported by the wicking element to the ejector to reduce air bubble accumulation at the ejector and maintain substantially continuous droplet generation.