In this work, we present a compact surrogate circuit for electro-quasi-static (EQS) head modeling. A three-shell geometry (brain, skull, scalp) is considered, and each layer is modeled through radial and tangential pathways, implemented as RC branches. Frequency-dependent tissue conductivity and permittivity are mapped into dispersive resistive and capacitive elements. The model is validated against a semi-analytical spherical-harmonics reference solution over multiple geometrical configurations and operating frequencies, demonstrating good agreement. Neglecting dispersion and capacitive pathways can lead to an overestimation of scalp potentials over the considered frequency range, highlighting the need for dispersive RC circuit modeling.

翻译：本文提出了一种用于电准静态头部建模的紧凑型等效电路。考虑三层球壳几何结构（脑组织、颅骨、头皮），通过径向和切向路径对各层进行建模，并实现为RC支路。频率相关的组织电导率和介电常数被映射为色散电阻和电容元件。该模型在多种几何构型和操作频率下，与半解析球谐参考解进行验证，展现出良好的一致性。忽略色散和电容路径会导致在所考虑频率范围内头皮电位的过高估计，突显了色散RC电路建模的必要性。