Electrode with charge-operated indicator

An electrode, comprising:

• a support having a subject side and a non-subject side opposite the subject side, wherein when the electrode is removably attached to a skin surface of a subject, the subject side is oriented generally facing the subject;
• first and second electrical contacts adapted to contact the skin surface of the subject, wherein at least a portion of the support spaces the first and second electrical contacts apart from the non-subject side;
• a charge-holding structure of the electrode electrically connected, in series, between the first and second electrical contacts and configured to store a charge, wherein:
• the charge-holding structure is at least partly (1) embedded in the support, (2) disposed on the subject side of the support, or (3) disposed on the non-subject side of the support;
• and
• the charge-holding structure is configured to, in response to an electrical connection between the first electrical contact and the second electrical contact through the subject, dissipate at least some of the stored charge in the charge-holding structure through the subject;
• and
• an indicator arranged so that at least a portion of the support spaces the indicator away from the subject side of the support, wherein the indicator is:
• electrically connected to the charge-holding structure;
• controlled by a charge between the first and second electrical contacts;
• configured to visibly change state in response to a change in the charge stored in the charge-holding structure;
• and
• positioned with respect to the support to be at least partly visible from the non-subject side of the support.