  This paper studies the phenomenon of conduction block in model neurons using
high-frequency biphasic stimulation (HFBS). The focus is investigating the
triggering of undesired onset action potentials when the HFBS is turned on. The
approach analyzes the transient behavior of an averaged system corresponding to
the FitzHugh-Nagumo neuron model using Lyapunov and quasi-static methods. The
first result provides a more comprehensive understanding of the onset
activation through a mathematical proof of how to avoid it using a ramp in the
amplitude of the oscillatory source. The second result tests the response of
the blocked system to a piecewise linear stimulus, providing a quantitative
description of how the HFBS strength translates into conduction block
robustness. The results of this work can provide insights for the design of
electrical neurostimulation therapies.
