Automation of an Atomized Meter Dose Inhaler for Lung Disease Patients
A reliable universal triggering system for atomized meter doseinhalers was built. Although the exact dosage into the airway system at different triggering delays was not possible to be determined by means of directly measuring its weight, the use of lasers reflection and high speed movie is an effective comparison method to determine the appropriate triggering moment. A set of transparent tubes was built to imitate the dimensions of a human trachea and bronchiole and two lasers were placed coaxially with such tubes. Light from the lasers was only reflected when the atomized medicine was passing through the tubes;so the longer the time the laser light could be seen, the more effective amount of dosage was being delivered to the lungs. From the experiment, it seems that the best delay time for triggering an inhaler is in the range between 0.7-1.s under the flow rate specified. Any time before that will result in medicine loss, and any time after that the patient might not be able to keep inhaling.