A device according to some embodiments of the present disclosure includes a housing configured to retain a battery, a primary antenna associated with the housing, and at least one processor in electrical communication with the battery and the primary antenna. In some embodiments, the at least one processor may be configured to cause transmission of a primary signal from the primary antenna to an implantable device during a treatment session of at least three hours in duration, wherein the primary signal is generated using power supplied by the battery and includes a pulse train, the pulse train including a plurality of modulation pulses.