A Robust Wearable Pre-Voiding Alarm System with High Tolerance to Sensor Placement Errors

Pre-voiding alarm systems have been shown to significantly reduce the incidence of nocturnal enuresis in children and can support the development of a normal urination routing for affected children. However, existing ultrasound-based alarm systems rely on the precise placement of the transducer at the optimal location and the system’s classification accuracy on a bladder’s filling status degrades significantly if the placement of the transducer deviates from the optimal spot. In this paper, we propose a custom-made ultrasound system which has two novel features: a pubis-bladder co-location and a multi-position training. The former guides a user to place an ultrasound transducer within an optimal range, while the latter enables the sensor system to offer high classification accuracy as long as the transducer is within the optimal range. Our simulation results suggest there is a significant improvement in terms of the system’s precision and recall indicators when both the pubis-bladder co-location and multi-position training are applied.