ThermoTK -Deep Heating through high-frequency electrotherapy A high-frequency current is applied to the patient. It enters the tissue almost not perceptible and is converted into heat in the target tissue. In contrast to direct or lowfrequency currents, the high frequency currents have the ability to penetrate superficial skin layers without energy loss. The energy is thus released only in the deeper tissue layers and converted into heat. The following pages provide background information, details on therapy form and characteristics of the device and the application.