Control Myoelectric: Evaluation of temporal and Parametric Patterns in deltoids medium.

FARFÁN, FERNANDO; POLITTI, JULIO CESAR; FELICE, CARMELO JOSÉ

Mundo Electrónico

Grupo TecniPublicaciones

Lugar: Barcelona; Año: 2007

0300-3787

Different digital processing methods in EMG signals recorded during static and dynamic contractions have been analyzed to use them as a control input to a dynamic assistance device. EMG signals registered in deltoids medium were analyzed using absolute mean value (AMV), RMS values, variance values (VAR), difference absolute mean value (DAMV), autoregressive (AR) and cepstral (CEP) coefficients. The differences between the abduction and adduction movements, and the influence of the inter-electrode distances on the EMG results were analyzed and quantified. The values AMV, RMS and DAMV showed a linear behavior with the arm position while the VAR values showed an exponential behavior during static and dynamic contractions. An increment in the dispersions of the temporal parameters was observed as the muscular contraction levels increased. The inter-electrode variation influences the values and dispersions of the temporal parameters. Significant differences between abduction and adduction have been observed in static and dynamics contractions from 20º to 70º and from 8º at 70º respectively. Conclusions. The following points must be considered in the implementation of a myoelectric control: a) The MAV, RMS and DAMV values present a poor sensitivity between 70º and 90º. b) The AR and CEP coefficients show no significant differences or a defined behavior related to the contraction level. c) The dispersions increase considerably with the arm position. d) The inter-electrode distance should be constant. e) Quantifiable differences have been detected in the amplitudes of the EMG, recorded during the abduction-adduction movements.