Patent attributes
An electronic sensor is configured to be carried by a person and to be used by the person to detect a cleanliness state of the person's hands. A single unit includes the electronic sensor and (a) a device to provide an indication of the cleanliness state of the person's hands and/or (b) a device to identify the person. A circuit that is configured to control how long after a cleanliness state of a person's hands has been determined to be clean, the state is presumed no longer to be clean. A badge that includes indicia identifying a person who carries the badge, a sensor to be used to detect a cleanliness state of the person's hands, and a visible indicator to indicate to other people the cleanliness state of the person's hands can be used in combination.