Abstract
A new method of computer analysis of the interference myoelectric activity is presented. The technique focuses on the time sequence of turning points of the e.m.g. Preliminary analysis shows that biphasic potentials produce a normalised spectral density of the e.m.g. turning points which is very close to 1·0 except for the low frequencies, whereas the occurrence of polyphasic action potentials is reflected by significant deviations from 1·0 for a wide range of frequencies. Experimental results obtained under sustained voluntary contraction in the human brachii biceps are presented. The observed alterations of the e.m.g. turning points spectral density were found to be in agreement with other independent reports which point to an increase of the number of polyphasic potentials in the e.m.g. with increasing contraction time. It is concluded that e.m.g. turning points spectral analysis is sufficiently selective and that it looks to be a sensible technique for the detection and quantification of the incidence of polyphasic potentials in the interference myoelectric activity.
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Lago, P.J.A., Jones, N.B. Turning points spectral analysis of the interference myoelectric activity. Med. Biol. Eng. Comput. 21, 333–342 (1983). https://doi.org/10.1007/BF02478503
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DOI: https://doi.org/10.1007/BF02478503