The effect of bipolar radiofrequency electrode diameters and spacing on subcutaneous temperature distribution based on finite element analysis

Bipolar radiofrequency (RF) cosmetology technology has the advantages of safety and painlessness, long duration, high patient tolerance, easy operation, etc., and has a wide range of applications. Electrode diameters and spacing significantly affect subcutaneous temperature distribution, and a systematic study of this is necessary. In this paper, the effect of different electrode diameters and spacing on the subcutaneous temperature distribution of bipolar radiofrequency aesthetics was investigated based on simulation analysis using COMSOL Multiphysics. The finite element skin model of bipolar radiofrequency was first established, and then the subcutaneous temperature distribution of bipolar radiofrequency with different electrode diameters and spacing was simulated by finite element analysis. The results showed that when the electrode diameters were gradually increased, the location of the hottest temperature target was basically unchanged, but the heating area was enlarged and the temperature rise was significant; On the other hand, when the electrode spacing was increased, the location of the hottest temperature target was gradually deepened, and the heating area was enlarged, but the rate of temperature rise was reduced. In particular, when the electrode diameters are in the range of 4-6 mm, the spacing is in the range of 2.37-4.25 mm, after being heated for 20 s, the depth of the hottest temperature target is about half of the electrode spacing, and the area of the 41-43 °C temperature range is the largest, which shows that it is suitable for household cosmetology device of bipolar RF.