Low Cost Wet Diaper Detector System

Abstract

The role of smart wet diaper detectors to health caregivers cannot be over-emphasized. Prolong wetness in patients and babies is one of the major causes of rashes especially when the wetness is not detected on time. Monitoring patients in real-time is essential for their well-being to know when to change a wet diaper and thus prevent serious skin problems. Although there are many smart diapers in the market, the high cost is a big challenge to prospective users. The design and implementation of a low-cost wet diaper detector have been presented in this thesis. The use of advanced technologies such as Bluetooth and wireless connectivity has helped in the development of smart solutions to enable caregivers to detect the wetness of diapers by sending notifications of wetness to their mobile phones. This thesis focused on providing a proof-of-concept prototype to implement a low-cost battery-free wetness detector unit. The prototype was designed to transmit a signal to the caregiver’s phone once wetness is detected. The wetness detector unit consists of the wet detector and the embedded In-play Nano-beacon Bluetooth Low Energy (BLE). Results show that the BLE operated at a very low voltage range of 1.1V to 3.6V and transmitted a wet signal to a phone up to 100m. The threshold voltage range (0.7V to 1V), at which the wet detector senses wetness was achieved using a voltage divider at the input of the wet detector. The prototype was designed using the Altium software environment and fabricated on a printed circuit board (PCB) using standard off-the-shelf components from the datasheet. Compared to other wet diaper detectors it has very low power consumption, is simple in design, and consumes a lesser amount of power. Hence it is relatively cheaper.