Monopolar vs. Bipolar RF
RF devices tend to market themselves as monopolar, bipolar or multipolar RF devices. Monopolar energy travels from the handpiece to a distant pole and requires a large ground electrode that is applied to the body. It penetrates up to 20mm, affecting both skin and subcutaneous fat. Bipolar energy travels from one pole on a handpiece to another, penetrating only 2mm to 4mm into the skin.
“Both work by causing bulk heating of the deep dermis,” says James Muze, vice president of development at Syneron Candela. “Bipolar uses symmetrical electrodes that can control the distribution of energy between the two and, more specifically, confine it to dermal structures when appropriate. Tripolar is a marketing term, not a scientific term. Devices with three or more poles use bipolar electrodes that switch between active pairs and inactive pairs.”
“There is only monopolar or bipolar current delivery,” says Inna Belenky, PhD, clinical director at Viora. “A multipolar system is actually a derivative of a bipolar system or a combination of two systems: bipolar and monopolar. For example, the octipolar system is an applicator that comprises four pairs of bipolar electrodes. The tripolar system has three electrodes: one acts as a positive electrode while the other two act as negative electrodes creating two pairs of a bipolar system.” Whether monopolar, biopolar or some combination of the two provides the best option for skin tightening has not been established by scientific studies.