Ablation pathway currents of a linear phased multi-electrode system

Multi-electrode catheter ablation has been used for treatment of drug refractory atrial fibrillation in humans. With a multi-electrode system, RF energy can be delivered to each electrode with a different voltage and phase angle, resulting in many current pathways, and more effective therapeutic lesion generation. Thus, the lesion dimension and uniformity can be shaped by controlling the current distribution among different pathways. This paper analyzes the influence of ablation electrode size, position and RF phase angle on the current pathways of a three-band electrode system. The analysis is based on a homogeneous integral equation model. When the RF energy is delivered asynchronously, both bipolar and unipolar currents contribute to ablation heating and lesion creation. The phase angle between adjacent electrode pairs has paramount impact on the current distribution among bipolar and unipolar pathways and thus renders an efficient control over lesion depth and uniformity