A system for tissue-impedance matched pulsed radio frequency (PRF) electrotherapy includes a power supply, an excitation board for generating PRF signals of a selectable frequency, the board having an input from the power supply. The system also includes a power amplifier for signals from the excitation...http://www.google.es/patents/US5584863?utm_source=gb-gplus-sharePatente US5584863 - Pulsed radio frequency electrotherapeutic system
