Cutting mechanism analysis of sharp-cutting-edge surgical electrodes on liver tissue

Surgical electrodes (SE) are widely used for soft tissues cutting while simultaneously providing haemostasis through energy applied. However, this energy application often leads to severe tissue adhesion and thermal damage, highlighting the need for a deeper understanding of cutting mechanisms and performance enhancements. To address these challenges, this study proposes replacing the traditional-rounded-edge surgical electrode (R-SE) with sharp-cutting-edge surgical electrode (C-SE) to improve cutting performance. Analysis of cutting force and temperature signals, along with assessments of tissue adhesion and thermal damage, reveals distinct thermal effects and electric field behaviours between the R-SE and C-SE, providing a more comprehensive understanding of the cutting mechanisms. The sharp edge leverages the tip effect to modify the energy field, altering the electric field and concentrating the current. This significantly optimizes the thermal effects and the interaction between the SE and the tissue. As a result, the C-SE reduces mechanical resistance during tissue penetration and cutting compared to the R-SE, leading to lower cutting forces across all tested power levels. Although the peak temperatures of the C-SE were similar to those of the R-SE, the C-SE consistently produced a thinner thermal damage zone and significantly reduced tissue adhesion. Furthermore, the C-SE demonstrated efficient cutting at lower power levels where the R-SE was ineffective. Overall, this study demonstrated that the C-SE exhibited significantly enhanced performance and provided a deeper understanding of the cutting process. These advancements contribute to more efficient and safer electrosurgery, which is crucial for a broader range of applications, especially in precision minimally invasive surgery.