AC and DC Excitation for Electrodermal Activity Measurement to Assess Sweat Gland Sensitivity and Activity for...

Peripheral neuropathy (PN), especially diabetic neuropathy, affects the peripheral nerves and deteriorates quality of life, increasing the risk of severe complications. Electrodermal activity (EDA) measurement, is a key for diagnosing these conditions, and is affected by sweat gland dysfunction. While EDA using direct current (DC) excitation has limitations due to polarization at the electrode-skin interface, the use of alternating current (AC) overcomes these limitations, providing a more accurate assessment of conductance and susceptance and a better understanding of the bioelectrical behavior of the skin.This study evaluates sweat activity in the plantar surface of the foot through EDA measurements using DC and AC excitation at different frequencies. Measurements were performed on six healthy subjects and conductance and susceptance were analyzed as a function of frequency. The results indicate that as frequency increases, conductance decreases and susceptance increases, reflecting increased penetration into the inner layers of the skin. AC measurements showed higher sensitivity, and less influence of polarization compared to DC measurements.This study suggests that AC excitation at frequencies close to 50 Hz could be an effective option for assessing sweat activity in patients with peripheral neuropathy, opening new possibilities for more accurate diagnosis and monitoring of the evolution of this condition.