SleepPoseNet: Multi-View Multi-Task Learning for Sleep Postural Transition Recognition Using UWB

Recognizing the movements during sleep is crucial for monitoring of patients with sleep disorders. However, the utilization of the deep learning approaches ultra-wideband (UWB)-based indoor applications for the classification of human sleeping postures has not been explored widely. This study investigates the performance of the off-the-shelf single antenna UWB in a novel application of sleep postural transition (SPT) recognition. The proposed Multi-View Multi-Task Learning, entitled SleepPoseNet or SPN, with time series data augmentation aims to classify four standard SPTs. SPN exhibits an ability to capture both time and frequency features, including the movement and direction of sleeping positions. Three cost functions for multi-views, multi-tasks, and classification are proposed to optimize SPN. The data recorded from 26 volunteers displayed that SPN with mean accuracy of $79.7 \pm 0.5 \%$ significantly outperformed the mean accuracy of $73.5 \pm 0.7 \%$ obtained from deep convolution neural network (DCNN) in a recent state-of-the-art work on human activity recognition using UWB. Apart from UWB system, SPN with the data augmentation can ultimately be adopted to learn and classify time series data in various applications. \end{abstract}