A tissue stimulation method which uses wave-guiding principles to
construct a focused point of stimulation at any location within a region
of electrically excitable living 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.