Abstract

Surface potentials on rectangular solid and half cylinder regions were calculated by the finite element method (FEM) and were compared with those calculated by the method of image in order to clarify applicability of the method of image to forward and inverse analyses of surface myoelectric potentials from the point of view of boundary effects. The estimation error in the inverse analysis by the method of image, which used the surface potentials calculated by FEM as the measured data, was also investigated. The results showed that the error of the surface potentials calculated by the method of image was less than 15% in the averaged amplitude and the estimation error of depth in the inverse analysis was less than 2mm, when the depth of current source was smaller than 10mm. The method of image is applicable to calculate surface potentials, because the effects of boundary is small when the depth of active muscle fibers is in this range.