Multifractal characteristics of external anal sphincter based on sEMG signals

This work presents the application of Multifractal Detrended Fluctuation Analysis for the surface electromyography signals obtained from the patients suffering from rectal cancer. The electrical activity of an external anal sphincter at different levels of medical treatment is considered. The results from standard MFDFA and the EMD--based MFDFA method are compared. Two distinct scaling regions were identified. Within the region of short time scales the calculated spectra exhibit the shift towards higher values of the singularity exponent for both methods. In addition obtained spectra are shifted towards the lower values of singularity exponent for the EMD--based MFDFA.Comment: 10 pages, 6 figures, 2 table

The distribution of information for sEMG signals in the rectal cancer treatment process

The electrical activity of external anal sphincter can be registered with surface electromyography. This signals are known to be highly complex and nonlinear. This work aims in characterisation of the information carried in the signals by harvesting the concept of information entropy. We will focus of two classical measures of the complexity. Firstly the Shannon entropy is addressed. It is related to the probability spectrum of the possible states. Secondly the Spectral entropy is described, as a simple frequency-domain analog of the time-domain Shannon characteristics. We discuss the power spectra for separate time scales and present the characteristics which can represent the dynamics of electrical activity of this specific muscle group. We find that the rest and maximum contraction states represent rather different spectral characteristic of entropy, with close-to-normal contraction and negatively skewed rest state.Comment: 6 pages, 5 figures, 1 tabl