Towards instantaneous phase difference on the COPD pre-discrimination

Chronic Obstructive Pulmonary Disease (COPD) is a common lung disease in Taiwan. People with COPD usually accompany dyspnea. When taking a spirometry test, they feel tired with measuring the tidal volume (VT). Some research estimated the VT by using respiratory inductive plethysmography (RIP), however, the movement between thoracic wall (TWM) and abdominal wall (AWM) might be distinct due to the different symptoms of COPD. Instantaneous phase difference (IPD) method was proposed for synchrony estimation between TWM and AWM continuity for healthy people. In this study, 26 subjects with COPD were recruited. The IPD was applied as a pre-discrimination of COPD symptoms and the prediction model for each type was further constructed. The error between real VT value and prediction VT value is calculated for validation. The results showed that three classes are classified and the errors are 20% 34% and 25% for each class in comparison with 36% for all. Based on this achievement, the IPD would be a useful index for assessing the progressive condition of COPD patient.