Sequential activation of multiple grounding pads reduces skin heating

Area of Science:

• Medical Devices
• Oncology
• Biomedical Engineering

Background:

• Radiofrequency (RF) tumor ablation is a standard treatment for unresectable tumors.
• Increased RF generator power is needed for larger ablation zones.
• Skin burns from ground pad heating are a major complication, limiting power and ablation size.

Purpose of the Study:

• To evaluate a sequential activation method for RF ground pads.
• To determine if sequential activation reduces skin temperature compared to conventional simultaneous activation.
• To assess the potential for reducing ground pad burns and enabling higher RF power.

Main Methods:

• Ex vivo experiments using a tissue phantom and three 5x5 cm ground pads.
• Application of 100 W RF power for 12 minutes between pads and an RF electrode.
• Measurement of leading edge temperature below pads and pad surface temperature profiles.
• Comparison of conventional (simultaneous) pad activation versus sequential activation (0.5s intervals).

Main Results:

• Sequential activation significantly reduced maximum leading edge temperature rise (p<0.001).
• Temperature rise below the leading edge was substantially lower with sequential activation (4.4-4.8°C) versus conventional (0.3-10.7°C).
• Sequential activation allowed for equalized leading edge temperatures across all pads.

Conclusions:

• Sequential activation of multiple RF ground pads effectively reduces maximum skin temperature.
• This technique may decrease the incidence of ground pad burns during RF tumor ablation.
• The findings suggest potential for using higher power RF generators safely.