Time and frequency analysis of signals from sternomastoid muscle in COPD patients and control group

Analysis of sternomastoid muscle (SMM) could become a non-invasive method for diagnosis of chronic obstructive pulmonary disease (COPD). This work studies electromyographic (EMG) and vibromyographic (VMG) signals from SMM during respiratory load tests, in six COPD patients and six normal subjects. These signals are related to electrical and mechanical activity of this muscle that could be different in patients and normal subjects. Time and frequency analysis are performed by means of root-mean-square (RMS) values, cross-correlation of EMG and VMG (EVC), mean and median frequency, and ratio of high and low frequency components (H/L). RMS values and H/L ratio show different behaviour at the end of respiratory tests between groups. Parameters calculated from EVC during tests are different in patient and control group.