Patent ID: 8755873

Claim:
An electrode contact quality evaluation device configured to evaluate a connection between at least one electrode and a skin surface, the electrode contact quality evaluation device comprising: a current source that generates a test current; an injection electrode selection circuit that supplies the test current to a selected injection electrode through a selected injection lead; a driven return circuit that generates a return current having opposite polarity to the test current; a return electrode selection circuit that supplies the return current to a selected return electrode through a selected return lead; a sense electrode selection circuit that supplies a signal obtained from one or more selected sense electrodes through one or more selected sense leads, to the driven return circuit; differential measurement circuitry that measures differences between signals present at the injection lead and the one or more sense leads and between signals present at the one or more sense leads and the return lead; and a processing device that evaluates the differences and generates an output representing a quality of at least one connection between at least one of the electrodes and the skin surface.