1. Calibration phase: to determine the degree of coughs' homogeneity between patients. The control source of data will be an audio-video (AV) system consisting in a microphone and a polygraph to record cough events along with an infrared webcam to register patient's movements. At the end of the calibration period, the data generated by the device will be analysed to determine if the coughs are homogeneous or heterogeneous, according to patient follow-up and AV outcomes. The degree of homogeneity will allow establishing the correct number of patients to be followed in the interventional phase (estimated 20 patients) and to set a threshold to define when there is an exacerbation.