Abstract: Objective We evaluated the utility of vibration response imaging in differentiating between asthma and COPD. Methods One hundred and twenty-four subjects with asthma or COPD were recorded, before and after the administration of a short-acting bronchodilator, using a computerized lung sound analysis device. Imaging data were compared with the clinical diagnosis, made by the standard Methods(medical history, physical examination, and spirometric indices). Results Blinded evaluation of images demonstrated a significantly higher rate of improvement in image dynamics, MEF, respiratory curve, shape and overall improvement following bronchodilator in subjects with asthma compared with those with COPD. EVP curve showed distinct patterns in timing and amplitude for asthma(accuracy 75%) and COPD(accuracy 79.6%). Combined analyses based on EVP curve evaluation and VRI imaging data demonstrated an overall 83.87% accuracy(78.33% for asthma, 89.06% for COPD) in differentiating between asthma and COPD. Conclusion Combined EVP curve and VRI imaging data evaluations of lung sounds are quite sensitive in distin-guishing between lung sound recordings of COPD and asthma individuals. Lung sound features of synchronization in timing and intensity provide Objective data that may further differentiate these two airway disorders.

Key words: vibration response imaging(VRI), asthma, COPD