We are dealing with Chronic Obstructive Pulmonary Disease (COPD), using a new methodology based on Passive Time Delay Technique (PTDT). Lung sounds were recorded using a multichannel stethoscope on 28 healthy subjects and 20 COPD patients. The sensors were distributed on the posterior and anterior chest wall. During recordings, all participants were breathing at matching airflow rates. Calculated time delay (TD) was identified for inspiration phase and an average TD value was provided after three repetitive measurements for each inspiration phase. TD computed in COPD patients: 440 ± 87 % (P < 0.05) was remarkably greater than time delay computed with normal subjects: 160 ± 10 % (P < 0.05). Results were presented as mean ± SD, standard deviation of time delay in ms. Significant P values (P < 0.05) were indicated using Wilcoxon test. Preliminary results are very encouraging to develop this technique and enhance COPD monitoring.
['Fatma Ayari', 'A.T. Alouani', 'Mekki Ksouri']
A Time Delay based approach to enhance lung diseases diagnostic