Oscillation spirometry and variability of airway resistance

The goal of this proposal is to develop a novel device for assessing lung function suitable for both children and adults. In order to measure a person's lung function, a physician will ask a patient to inhale deeply and exhale as hard and as fast as possible through a tube. The amount of air the person gets through the tube determines how healthy the airways are. Unfortunately this measurement requires significant effort and training and thus children under the age of 6 where asthma is usually first diagnosed cannot reliably do the measure. Currently there is no recommended objective measurement for lung function in children. We are developing a new device known as an oscillation spirometer that may help fill that gap. It moves small amounts of air that puff into and out of a patient's mouth and airways. The more pressure required to get that air in and out, the more narrow the device determines the airway must be. By tracking how this changes for about 3 minutes, we get another measure of how much airway diameters are changing. This measure is interesting, because we have found that the airway diameters in asthmatics are changing much more than in people without asthma. Also we have found that when an asthmatic takes a puffer, it not only dilates narrowed airways, but it also reduces their variation¬ - or in other words, it calms them down. The new device we are developing will perform standard spirometry and will also measure how difficult it is to puff air into a patient's lungs, and it will finally also measure how that changes over time. As well as building a new device, we are exploring how sensitive this new measurement is to changes in an asthmatic's airways, and how this measurement relates to the severity of asthma.