What's the Radio Frequency(RF)?
Radio frequency (RF) refers to oscillatory change in voltage or current in a circuit, waveguide or transmission line in the range extending from around twenty thousand times per second (20 kHz) to around three hundred billion times per second (300 GHz), roughly between the upper limit of audio and the lower limit of infrared. The term does not have an official definition, and different sources specify slightly different upper and lower bounds for the frequency range. RF usually refers to electrical rather than mechanical oscillations. However, mechanical RF systems do exist (see mechanical filter and RF MEMS).
RF in Medicine
Radio frequency (RF) energy, in the form of radiating waves or electrical currents, has been used in medical treatments for over 75 years, generally for minimally invasive surgeries using radiofrequency ablation including the treatment of sleep apnea. Magnetic resonance imaging (MRI) uses radio frequency waves to generate images of the human body.
Radio frequencies at non-ablation energy levels are sometimes used as a form of cosmetic treatment that can tighten skin, reduce fat (lipolysis), or promote healing.