Design and Evaluation of Multi-Electrode Configurations for Transcutaneous Frontal Nerve Activation

Conventional migraine treatments often come with undesirable side effects. One alternative approach uses a wearable neuromodulation device that stimulates nerves in the forehead. However, clinical studies have reported modest effectiveness, and some users experience discomfort or pain. These issues may be associated with electrode design, which can require higher stimulation currents to achieve activation. This study aims to evaluate the stimulation currents required by the migraine neuromodulator device and to explore whether modifying electrode arrangement can lower these current levels, which may potentially improve patient comfort and treatment compliance. To accomplish this, a hybrid computational framework combining a 3D volume conductor model with biophysical nerve dynamics was deployed. To capture population diversity, forty distinct nerve models were generated based on statistical variations in trajectory paths and evaluated across five electrode array configurations. The findings show that the proposed electrode array (EA) and neuroanatomical variability significantly influence stimulation thresholds. Simulations of the Cefaly electrode produced current thresholds ranging from 9 mA to 30 mA across the models. When the proposed EA was applied by aligning with nerve pathways, the required currents dropped substantially, ranging from 0.5 mA to 9 mA. Additionally, this design reduced calculated peak spatial current density across superficial tissue layers-a factor associated with cutaneous discomfort-which may support improved tolerance and long-term treatment adherence in clinical practice.