Abstract: Among other things, systems to encourage compliance with hand washing procedures can include: an infrared emitter that projects a first infrared beam with a transverse cross-section having a first axis and a second axis that is shorter than the first axis, the transverse cross-section having a maximum length along the first axis, the infrared emitter modulating the first infrared beam to transmit a first identification signal; wherein the infrared emitter projecting the first infrared beam is placed such that the first axis of the transverse cross-section of the first infrared beam is substantially parallel to a boundary.

Abstract: Among other things, systems to encourage compliance with hand washing procedures can include: an infrared emitter that projects a first infrared beam with a transverse cross-section having a first axis and a second axis that is shorter than the first axis, the transverse cross-section having a maximum length along the first axis, the infrared emitter modulating the first infrared beam to transmit a first identification signal; wherein the infrared emitter projecting the first infrared beam is placed such that the first axis of the transverse cross-section of the first infrared beam is substantially parallel to a boundary.

Abstract: Among other things, an entry monitor has circuitry to detect when a person enters a monitored space and an indicator perceptible to other people in the space to indicate a cleanliness state of the hands of the person who has entered the space.

Abstract: Among other things, from a wireless device, a command is transmitted to wearable monitors within range of the wireless device to update their states to a non disinfected state of the hands of users of the wearable monitors.

Abstract: Among other things, an entry monitor has circuitry to detect when a person enters a monitored space and an indicator perceptible to other people in the space to indicate a cleanliness state of the hands of the person who has entered the space.

Abstract: 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.

Abstract: 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.