A device for delivering energy as a function of degree coupling may include an external unit configured for location external to a body of a subject and at least one processor associated with the implant unit and configured for electrical communication with a power source. The device may further include a primary antenna associated with the at least one processor. The processor may be configured to determine a degree of coupling between the primary antenna and a secondary antenna associated with the implant unit, and regulate delivery of power to the implant unit based on the degree of coupling between the primary antenna and the secondary antenna.