Principles of radiofrequency needle ablation therapy

Radio frequency (rf)

Radio frequency is a type of high-frequency vibration with a frequency of 150,000 times per second. The human body is a complex structure composed of many organic and inorganic substances. Body fluids contain a large number of dielectric, such as ions, water, colloidal particles, etc. The human body mainly relies on the movement of ions to conduct current. Under the action of high frequency alternating current, the direction of ion concentration changes with the direction of current positive or negative half cycle. Under high frequency oscillation, the ions between the two electrodes move rapidly along the direction of the power line and gradually change from a moving state to a vibrating state. Due to the different size, mass, charge and moving speed of ions, ions rub against each other and collide with other particles, resulting in biothermal interaction. Due to the poor heat dissipation of the tumor, the temperature of the tumor tissue is higher than that of the adjacent normal tissue. In addition, cancer cells are sensitive to high heat, which kills cancer cells without side effects.

Effect of heat

The mechanism of radiofrequency therapy apparatus with ablation and cutting function is mainly thermal effect. Radiofrequency waves are essentially electromagnetic waves within a specific range. At present, most medical radio frequencies are 200KHz~750KHz. (Endoscopic) radiofrequency therapy instrument operating frequency of 400KHz. When radiofrequency current flows through human tissues, the rapid change of electromagnetic field makes the positive and negative ions in cells move rapidly, so that the friction between them and other molecules and ions in cells heats up the pathological site, resulting in the evaporation, drying, shrinkage and shedding of water inside and outside cells, resulting in aseptic necrosis, so as to achieve the purpose of treatment.