Biomedical Electrodes: Interface and Impedance

This lecture covers the general context of sensors, transducers, and electrodes, focusing on biomedical electrodes. It discusses the importance of electrode design for detecting bioelectric events, applying therapeutic impulses, and minimizing artifacts. Issues related to electrode impedance, interface characteristics, and polarization are explored. The lecture also delves into the modeling of electrode-electrolyte interfaces, equivalent circuit models, and impedance spectroscopy. Strategies to avoid tissue damage, such as using biphasic pulses and noble metal electrodes, are presented. The impact of motion artifacts, electrode materials, and electrode design on signal quality is discussed, along with practical considerations for body surface recording electrodes.