High spatial resolution, focused electrical stimulation of electrically-excitable tissue

A theoretical method is presented which uses wave-guiding principles to construct a focused point of stimulation at any location within a region of electrically-excitable tissue. The excitation is formed through the constructive interference of different frequency wave energies, traveling at frequency-dependent velocities, which coalesce at the stimulation point. Further energy is brought to the stimulation point through reflection(s) at the boundaries of the wave-guiding structure. The resulting excitation signal depends upon several factors, including pulse envelope and duration, allowable frequency range, and stimulation time. A necessary trade-off exists amongst stimulation time, pulse duration, and the degree of focus.