Electrolytic Cell Design to Simulate the Electrochemical Skin Response

Small fiber peripheral neuropathy is an early complication of diabetes. Electric skin response to some stimulus, as electrochemical skin conductance ECS, is a promising route in the early follow-up of such diseases. It is related to sweat gland innervations and their permeability to chlorides and protons; it is non-invasive, quantitative and reproducible. In routine clinical use, it could allow to better adapt the treatments and improve the adhesion for preventing pathological progress, thus reducing colossal healthcare costs. To optimize the measurements and understand the electrochemical behavior of electrodes, an original electrolytic cell was designed in lab scale. Thereby, an electrolyte is chosen to mimic sweat composition. For achieving currents range of ESC in vivo measurements, the original idea was to play on electrolyte viscosity by adding sucrose. In this paper, the novel electrolytic lab cell is presented with its limiting kinetics processes. A model of chloride migration to the anode and global electric model dedicated to the cell are proposed. Cell parameters are thoroughly studied, e. g. the resistance, which is equivalent to the inverse of ESC, by exploiting the models and through in vitro experiments, with protocols focusing on reproducibility. This original approach establishes, inter alia, an important result: the resistance is accurately retrieved using linear voltammetry, whereas single voltage measurement fails notably and is, therefore, unsatisfactory.