Readability Of Reassigned Scalograms And Extraction Of Spectra Features For Signal Analysis
Free (open access)
S. Mekaoui, A. Houacine & T. Gharbi
In this paper, wavelet scalogram is being used. The wavelet scalogram presents some disadvantages. This is particularly true for time-frequency analysis and representation which present inconvenient cross-terms. MMG signals (Mechanomyograms) are acquired via a home probe high sensitive optical sensor. The data obtained from 2 healthy subjects and 2 patients sat and tested under drastic conditions are analyzed to characterize the dynamic properties of the MMG and to determine their frequency contents as well. We developed the reassignment form of the scalogram which improves its resolution and readability. A plot of the scalogram contours is also presented to test the direct readability of the scalogram representations. Spectra features are extracted and relevant parameters are assessed such as the power spectral density, the mean frequency, the average frequency and the well known ratio HF% that characterizes the dynamic characteristics of the tested muscles. For that purpose, the number of subjects had been increased to 24 healthy subjects and up to 18 patients affected by different specific muscular diseases.
MMG Signals (Mechano-myograms), Reassigned Wavelet Scalogram, power spectral density, mean and average frequencies, MMG rms value, MMG average value, HF % ratio value