Monitoring Diaper Condition Using the Impedance Variation of a Dipole Antenna

摘要

To prevent skin rashes and skin eruption in babies, timely detection of urine and feces on a diaper is important. Currently, several smart diaper systems are being developed as a means of sensing excretion and alerting the caretaker to change the diaper. We propose to use the input impedance variation of a single on-diaper antenna to sense the urine and feces of a baby. By using an antenna as a sensor, there is no need to use other sensors, although an RF transmitter is necessary by default. We will locate a microstrip dipole patch antenna at the bottom of a diaper. The antenna is designed to resonate at 5.7 GHz. It senses urine and feces, for which we rely on the change to input impedance of an on-diaper antenna that results when a baby excretes urine or feces. The diaper is modeled with three layers, and the EM simulation is performed by FEKO. We observe the antenna impedance change with diverse diaper conditions and compare the results.