Ca. Sinderby et al., INFLUENCE OF THE BIPOLAR ELECTRODE TRANSFER-FUNCTION ON THE ELECTROMYOGRAM POWER SPECTRUM, Muscle & nerve, 19(3), 1996, pp. 290-301
This study demonstrates the impact of the bipolar electrode transfer f
unction on the canine diaphragm electromyogram (EMG) power spectrum, a
s evaluated with a new electrode design and implantation technique, Th
e results show that: (a) changes in interelectrode distance transforme
d single-peaked power spectrums into double-peaked spectrums; (b) the
mean action potential conduction velocity (<(APCV)over bar>), and powe
r spectrum center frequency (CF) and median frequency (MF), are relate
d for interelectrode distances of 5 and 10 mm, but not for 15 and 20 m
m; and (c) CF, MF, - 3-dB, and - 6-dB bandwidth values depend on inter
electrode distance. We conclude that bipolar electrodes, with a nonfix
ed interelectrode distance, cannot be used for physiological interpret
ations of the EMG power spectrum. Nonetheless, power spectrums obtaine
d with fixed and appropriate interelectrode distances can be trusted,
if the electrodes are positioned in the direction of the muscle fibers
and in regions with low densities of motor endplates. (C) 1996 John W
iley & Sons, Inc.