Wee problem solved by Japanese diaper-duty sensor - Channel NewsAsia
In a nutshell, a Japanese firm has found a way to mass produce cheap, one-time use wetness indicators. These sensors are very thin and are placed inside a diaper, and will detect any moisture produced. A caregiver who has a 'receiver' will then be notified that the diaper needs changing.
This might make for some interesting scenarios if adopted into the ABDL world. If you get the chance to experience this, what would you use it for?