A Lead Field Two-Domain Model for Longitudinal Neural Tracts—Analytical Framework and Implications for Signal Bandwidth

Figure 2

(a) Geometry of the model. The axon is located at a distance from the body surface. The observation electrode is placed at the origin. (b) Membrane potential along the axon. At the peak of is located at . The membrane potential propagates with a velocity in the direction. Membrane potential gradients generate distributed moving dipole sources . They are shown in (b) and (a). Due to the opposite orientation of de- and repolarization, a quadrupole source pattern is obtained. (c) The lead field is an odd function with a single oscillation. The distance between the two extrema is .