Devices, systems and methods for applying electrical impulse(s) to one or more selected nerves are described. An electrical stimulator is introduced through a to a target location within, adjacent to, or in close proximity with, the carotid sheath. The stimulator has an antenna that allows it to be powered solely by far-field or approximately plane wave electromagnetic radiation, having frequencies in the range of 0.3 to 10 GHz. Electrical impulses are applied through the stimulator to a vagus nerve to stimulate, block or otherwise modulate activity of the nerve and treat the patient's condition. The stimulator uses an adjustable number of fixed voltage (or fixed current) pulses with fixed duration to elicit desired changes in nerve response, the timing of which are controlled by an external power transmitter and controller.
