Patent US10525220

a housing comprising a mouthpiece located at an airflow exit of the housing, and an airflow inlet flow element positioned at an airflow entrance of the housing;

a multiple fluid ampoule disposed within or in fluid communication with the housing comprising a first fluid reservoir and at least a second fluid reservoir, the first fluid reservoir for receiving a first volume of fluid comprising the first agent, and the second fluid reservoir for receiving a second volume of fluid comprising the second agent;

at least one electronically actuated ejector mechanism in fluid communication with the multiple fluid ampoule and configured to generate the one or more 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 at least one ejector mechanism upon sensing a pre-determined pressure change within the housing to thereby generate the one or more ejected stream of droplets;

the at least one 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 one or more ejected stream of droplets; and

wherein the housing, airflow inlet flow element, and mouthpiece are configured to facilitate non-turbulent airflow across an exit side of the aperture plate and to provide sufficient non-turbulent airflow through the housing during use.