Abstract: A pressurized metered-dose inhaler requires good synchronization between the activation of the inhaler and the inspiration by the patient. Processing is carried out on the video frames filming the patient to qualify the actuation of the pressurized metered-dose inhaler according to two criteria: regarding the pressing by the patient's actuating fingers on a trigger member of the inhaler and regarding the actual compression of the inhaler. Processing of an audio signal recording the patient at the same time is also carried out to detect an inhalation by the patient. A temporal correlation of the probabilities obtained as results then makes it possible to qualify the synchronization between the actuation of the inhaler by the patient and the latter's inspiration, and thereby indicate a proper use or improper use of the inhaler.