Method for releasing controlled amount of aerosol medication

A method for releasing a controlled amount of aerosol medication from a valved canister containing the medication for intrapulmonary delivery to a person during inhalation breath flow comprising the steps of:

• a) monitoring the inhalation breath flow through a flow path and determining the beginning and the end of the inhalation;
• b) measuring the flow rate of the sensed inhalation breath flow;
• c) determining the flow volume of the inhalation breath flow as a function of the measured flow rate;
• d) providing a flow rate minimum threshold and a flow rate maximum threshold and providing a minimum flow volume threshold and a maximum flow volume threshold;
• e) comparing the measured flow rate to the minimum flow rate threshold and the maximum flow rate threshold;
• f) comparing the determined flow volume to the minimum flow volume threshold and the maximum flow volume threshold, said comparing the determined flow volume being performed when the determined flow rate is between the minimum and maximum flow rate thresholds;
• g)
• i) releasing a controlled amount of medication when the determined flow volume is between the minimum and maximum flow volume thresholds,
• ii) declaring a failed breath event if the inhalation has ended and the determined flow volume is not between the minimum and maximum flow volume thresholds, or
• iii) returning to step (a) if the inhalation has not ended and the determined flow volume is not between the minimum and maximum flow volume thresholds.