Selective stimulation of nerve fascicles in neuroprosthetic systems

We address the problem of excitation current design for position-selective stimulation of nerve fascicles in neuroprosthetics devices. We show that a set of point electrodes arranged around a nerve trunk can be used to approximate any arbritary activation pattern, and provide a non ad hoc method to determine the appropriate excitation current profile and fiber excitations. The proposed method is investigated through extensive computer simulations, taking into consideration issues such as fascicle geometry, fiber diameter distribution and the complete ignorance in the relative positions of the Nodes-of-Ranvier.