The generator of AM EMFs consists of a battery-driven radiofrequency (RF) EMF generator connected to a 1.5 m long 50 ? coaxial cable, to the other end of which a stainless-steel spoon-shaped mouthpiece is connected via an impedance transformer. The RF source of the device corresponds to a class C amplifier operating at 27.12 MHz. The carrier frequency is AM with a modulation depth of 85±5%, whereas the modulation frequency is generated by a digital direct synthesiser with a resolution of 10-7. The treatment sequence is controlled by a microcontroller (Atmel AT89S8252, Fribourg, Switzerland), that is, duration of session, sequence of modulation frequencies and duration of each sequence can be programmed via PC over a RS232 interface. The RF output is adjusted to 100 mW into a 50 ? load, which results in an emitting power identical to that of the device used for the treatment of insomnia.