Study of myographic signals from sternomastoid muscle in patients with chronic obstructive pulmonary disease

Abstract

Analysis of the respiratory muscle activity is a promising technique for diagnosis of respiratory diseases, such as chronic obstructive pulmonary disease (COPD). The sternomastoid muscle (SMM) was selected to study the activity of respiratory muscles due to its accessibility in order to define a noninvasive analysis. The aims of this work are two: analyze the relationship between the SMM function and pulmonary obstruction, and study the influence of spectral estimator on frequency parameters related with the muscle activity. For the first goal, we propose the analysis of vibromyographic and electromyographic signals from the SMM to study the muscle function during two ventilatory tests. Activity of SMM was found by means of several indexes: root-mean-square (rms) values, mean and median frequencies, and ratio between high and low-frequency components. For the second goal, spectral analysis was performed by means of nonparametric methods: Correlogram and Welch periodogram, and parametric methods: autoregressive (AR), moving average (MA), and ARMA models. It is deduced that these indexes show muscle activity and certain fatigue of the SMM, whose muscle function depends on the level of pulmonary obstruction, and they depend a lot of spectral estimator being the more suitable an AR model with high order.

Evaluation of Respiratory Muscles Activity by Means of Cross Mutual Information Function at Different Levels of Ventilatory Effort

“…In the model of normal upper airway function, subatmospheric pharyngeal pressures generated by the contraction of the diaphragm must be balanced by opposing forces generated by upper airway dilator muscles such as the genioglossus, in order to prevent a collapse of the upper airways [3]. Sternomastoid is an accessory respiratory muscle activated at high levels of ventilatory effort associated with exercise or with chronic obstructive pulmonary disease [4]. Individuals with OSAS experience intermittent collapse of the upper airways during sleep [3].…”

Influence of estimators of spectral density on the analysis of electromyographic and vibromyographic signals

“…1. This is in agreement with other studies where segments of this duration have been considered locally stationary (BALESTRA et al, 1988;MANANAS et al, 1996MANANAS et al, , 2000POPIVANOV and TODOROV, 1986). Furthermore, ergodicity is assumed to permit signal analysis based on a single observation because only one respiratory cycle is considered in the estimation of PSD (TAVATHIA and RANGAYYAN, 1992).…”

“…Furthermore, they permit differentiation of respiratory muscle function between normal subjects and patients with chronic obstructive pulmonary disease (COPD) (MANANAS et al, 2000).…”

Electromyographic activity of sternocleidomastoid muscle in patients with Parkinson’s disease

“…Among the respiratory muscles evaluated with EMG, the sternocleidomastoid muscle (SCM), a superficial muscle, has been extensively studied in the literature through surface EMG (Estenne et al, 1984;Troyer et al, 1994;Ribeiro et al, 2002). The SCM is the main breathing accessory muscle (Troyer et al, 1994), becoming active only in high levels of ventilation in healthy subjects (Mañ anas et al, 2000).…”

“…Respiratory muscle evaluation on patients with respiratory disorders can be done using different methods, including surface electromyography (EMG) (Mañ anas et al, 2000;Troyer et al, 1994). Duiverman et al (2004) showed the reproducibility and the sensibility of electromyography in detecting the electrical activity of respiratory muscles in healthy subjects and patients with chronic obstructive pulmonary disease.…”