Inhalation Device For Delivering An Atomized Mixture Of Liquids With A Regulated Mixing Ratio

An inhalation device for delivering an atomized mixture of liquids with a regulated mixing ratio, comprising

• two reservoirs (102), each storing a respective liquid,
• for each reservoir (102) a respective piezoelectric actuator (10a, 10b, 100) for atomizing the respective liquid, and
• a pressure sensor (16a, 16b) for detecting a user inhalation,
• characterized in that
• the inhalation device further comprises a regulating electric circuit for regulating a flow rate of the atomized liquids by controlling the piezoelectric actuators (10a, 10b, 100), wherein the regulating electric circuit comprises a controller (18) and wherein the pressure sensor (16a) is connected to the controller (18) for enabling atomizing only during the user inhalation,
• the regulating electric circuit further comprises an output stage (20a, 20b) for each of the piezoelectric actuators (10a, 10b, 100), wherein each output stage (20a, 20b) comprises
• an inductor (12a, 12b) forming a resonant circuit with the respective piezoelectric actuator (10a, 10b, 100) having an inherent capacitance, and
• a switch (14a, 14b) for driving the output stage (20a, 20b) by a respective output PWM signal having a duty cycle, wherein the output PWM signal is generated by the controller (18),
• the mixing ratio and the flow rates of the atomized liquids are determined by the duty cycles of the output PWM signals, and
• for each reservoir (102) the inhalation device comprises a respective liquid transferring member (104) made of a capillary material and being in contact with the respective liquid in the reservoir (102) and with the respective piezoelectric actuator (10a, 10b, 100).