基于数值仿真方法的体外除颤电极配置分析与优化

Optimization and Analysis of Electrode Configurations for Transthoracic Electrical Defibrillator Based on Numerical Simulation Method

体外电除颤器的电极配置(位置、大小、形状)直接影响着除颤效果的好坏,合理的配置模式能降低高压电刺激对皮肤和心肌的损伤、减轻患者的痛苦、提高除颤急救的成功率。运用数值仿真方法,初步研究了多种电极配置模式下(24种电极对位置、4种电极面积及3种电极形状)体外电刺激在心脏区域的电场分布情况,获得了电场分布均匀度(UNIF)、除颤电压阈值(DFT)、能量效率(EFF)等统计分析结果。结果比较显示,右上前胸-左下侧胸电极对位置、大小133cm2、形状为椭圆的电极配置方式的除颤效果最佳,优于先前报道的左前胸-右后背式圆形电极对配置模式,更适合体外电除颤的临床应用。

The efficacy of transthoracic electrical defibrillator is highly dependent on the configurations（placement,size,and shape） of surface electrodes,which can be optimized further to improve the success rate of defibrillation while minimize myocardial damage and decrease patient＇s pain during defibrillation. Using numerical simulation method,24 different electrode-pair placements,4 different electrode sizes,and 3 different electrode shapes were modeled and simulated with the detailed Utah torso model under an applied electrical stimulation, respectively.Furthermore,the myocardial electric-field distribution resulting from a defibrillation shock were determined and compared quantitatively with three different defibrillation criteria including the defibrillation threshold voltage（DFT）,the efficiency fraction of delivered current reaching the heart（EFF）,and the uniformity of current density distributions in the heart（UNIT）.Our results indicated that the optimal electrode configuration（two elliptical-shape electrodes with the size of 133 cm^2 located respectively at the right-up-anterior-thorax and left-down-lateral-thorax） was more efficient than that reported in previous literature（two circular-shape electrodes located respectively at left-anterior-thorax and right-posterior-back）.The electrode configuration reported in this paper is better in design for clinical application of external defibrillation.