A device according to some embodiments may include a primary antenna configured to be located external to a subject. The device may also include at least one processor in electrical communication with the primary antenna and configured to receive a condition signal from an implantable device, the condition signal indicative of a precursor to sleep disordered breathing, and cause transmission of a primary signal from the primary antenna to the implantable device, in response to the condition signal, to stimulate at least one nerve in response to the precursor to sleep disordered breathing.