Authors:
Eleonora Sulas
;
Luigi Raffo
;
Marco Monticone
and
Danilo Pani
Affiliation:
University of Cagliari, Italy
Keyword(s):
Scoliosis, EMG, Adaptive Filters, RLS, ECG.
Abstract:
Adolescent idiopathic scoliosis is defined as a three-dimensional deformity of the spine and trunk occurring
in about 2.5% of most populations. It is usually analyzed radiographically, but electromyography (EMG)
can be also used, since muscles activity is correlated to deformity progression. EMG ratio is a numerical
index used in the literature to provide information about scoliosis progression. Trunk EMG recordings are
strongly affected by the electrocardiogram (ECG) of the subject. Previous studies removed this interference
from the EMG signal by blanking the QRS complexes of the ECG but, as a consequence, several segments
of the signal are removed. Furthermore, the other relevant ECG waves such as P and T are not cancelled and
can invalidate the computation of parameters such as the EMG ratio. The aim of this study is to evaluate the
possibility, by means of a modified recording protocol including further electrodes, to completely remove the
ECG interference by adopting a multi-re
ference recursive least square (RLS) adaptive filter. The results of
the study reveal how the complete clearing of the ECG from the EMG channels leads to different numerical
values of the index, compared to the QRS blanking, more reliable and meaningful for the clinicians.
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