A device for controlling operation of a nerve-modulating implant unit from a location external to the body of the subject is provided. The device may include a flexible substrate configured for removable attachment to a subject's skin, a primary antenna disposed on the flexible substrate, and at least one processing device. The processing device may be configured to cause generation of a modulation control signal and application of the modulation control signal to the primary antenna in order to wirelessly transmit the modulation control signal to a secondary antenna on the implant unit to cause modulation of at least one nerve using energy transmitted wirelessly from the primary antenna to the secondary antenna, and cause a plurality of predetermined alterations of at least one characteristic of the modulation control signal over successive applications of the modulation control signal during a therapy period.
