Structural design and experimental verification of single-wire low-temperature plasma ablation electrode
10.3760/cma.j.cn121382-20240112-00201
- VernacularTitle:单线型低温等离子消融电极的结构设计与实验验证
- Author:
Qun XU
1
;
Chengli SONG
;
Lin MAO
;
Liuxiao CHEN
;
Tong WU
;
Yangzhi LIU
;
Lin XIN
Author Information
1. 上海理工大学健康科学与工程学院，教育部微创医疗器械工程研究中心，上海 200093
- Keywords:
Electrode;
Low temperature plasma;
Tissue ablation;
Microbubbles;
Thermal damage
- From:
International Journal of Biomedical Engineering
2024;47(2):101-107
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To design a single-line low-temperature plasma ablation electrode, aiming to solve the problem of uniform, continuous and stable microbubbles generated by conventional electrodes, and improve the ablation and cutting effect of low-temperature plasma.Methods:The structures of low temperature plasma three-wire electrode and single-line electrode were modeled in SolidWorks 2021 3D modeling software, and the prototype was made by 3D printing. The finite element analysis of electric field and temperature field of the two kinds of electrode ablation process was carried out by COMSOL Multiphysics 6.1 software, and the validity and correctness of the finite element simulation model were verified by temperature test experiment, and the ablation effect and plasma excitation process of the two kinds of electrode were compared by tissue ablation experiment and low temperature plasma excitation experiment.Results:The results of finite element analysis showed that the maximum surface temperature of three-wire electrode and single-wire electrode were 70.2 and 63.3 ℃, respectively, and the surface temperature of single-wire electrode was more ideal, and the maximum electric field intensity of the two electrodes was more than 1.0 × 10 7 V/m, which met the electric field condition of microbubble breakdown. The electric field intensity of the two ends of the three-wire electrode was much higher than that of the other regions, while the electric field intensity of the single-wire electrode had no obvious sudden change and fluctuation. The experimental values of the temperature at the electrode surface and a distance of 1 cm on the electrode surface were basically consistent with the simulation values, the degree of fit was good, and the relative error was 3.2%. The highest ablation temperature of single linear electrode on pig fat was 46.8 ℃. After ablation, there was no coking area in morphology, and the tissue cutting depth of 0.5 mm could be reached in 1 s. When connected to the energy platform, microbubbles would occur on the working electrode surface of the single-wire electrode; when 6 ms was electrified, the working electrode surface was completely covered by microbubbles; when 9 ms was energized, the low-temperature plasma was excited and the blue-purple plasma could be seen; when 25 ms was energized, the microbubbles were still regular and stable. Conclusions:A kind of single-line low-temperature plasma ablation electrode is designed, which can produce uniform, continuous and stable microbubbles and achieve better ablation and cutting effect than the traditional electrode.
