A research laboratory at Japan’s Ritsumeikan University has developed a monitoring system for wet diapers that consists of a self-powered sensor/transmitter and a receiver and is supposed to assist staff in hospitals and nursing homes in performing diaper checks with elderly patients. The sensor kit has to be placed inside the diaper and sends signals to the receiver unit, which was co-developed in collaboration with Seiko Epson.
Both the sensor and the accompanying wireless transmitter are powered by a built-in battery that can generate electricity following a chemical reaction in the presence of urine. Once this happens, the sensor kit can transmit signals to a receiver located as far as 3 meters away.
The university lab says their wet diaper monitoring system is still in prototype mode. One possible area for improvement is to add circuitry to the sensor system so that a single system can monitor a group of people, for example in a nursing home.