I’ve always been a fan of shame and blame, humility and hubris, carrots and sticks.

People can be complicated.

According to The Atlantic, a number of companies have designed systems that aim to nudge doctors and nurses into washing their hands regularly. One of these devices, a badge made by Biovigil, aims to exploit a very powerful emotion: shame.

When a doctor enters an exam room, the badge chirps and a light on it turns yellow—a reminder to the doctor as well as an alert to the patient that he is about to be touched by someone with unclean hands. If the doctor doesn’t wash her hands, the light flashes red and the badge makes a disapproving noise. After the doctor waves a freshly sanitized hand in front of the badge, alcohol vapors trigger a sensor that changes the light from red to green. Other systems include HyGreen, which also uses badges; Hyginex, a wristband that can tell when a user dispenses hand sanitizer (and vibrates if he or she doesn’t); and SwipeSense, which includes a hand-sanitizer dispenser that clips onto scrubs.

Each of these devices generates a log that’s uploaded to a database of what HyGreen calls “all hand hygiene events in the hospital”—a rundown of who’s washing up, and who isn’t. The data could help hospitals engage in after-the-fact analysis of how an outbreak occurred, and, with any luck, might help them to prevent the next one.