When electodes are used to record the electrocardigram, an electrolyte gel is usually put between them and the surface of the skin. this makes it possible for the metal of the electrode to form metallic ions that move into the electrolyte gel. often, after prolonged use, this electrolyte gel begins to dry out and change the characteristics of the electrodes. draw an equivalent circuit for the electrode while the electrolyte gel is fresh. then discuss and illusttrate the way you expect this equivalent circuit to change as the electrolyte gel dries out. in the extreme case where there is no electrolyte gel left, what does the equivalent circuit of the electrode look like? how can this affect the quality of the recorded electrcardiogram?