Functional electrical stimulation is a powerful
tool for restoration of function after nerve injury. However
selectivity of stimulation remains an issue. This paper presents
an alternative stimulation technique to obtain fiber size-selective
stimulation of nerves using FDA-approved electrode implants.
The technique was simulated for the ventral roots of
Xenopus Laevis, motivated by an application in bladder control. The
technique relies on applying a high frequency alternating
current to filter out action potentials in larger fibers, resulting
in selective stimulation of the smaller fibers. Results predict that
the technique can distinguish fibers with only a 2 µm difference
in diameter (for nerves not exceeding 2 mm in diameter). The
study investigates the behaviour of electrically blocked nerves
in detail. Model imperfections and simplifications yielded some
artefacts in the results, as well as unexpected nerve behaviour
which is tentatively explained.