DSleepNet: Disentanglement Learning for Personal Attribute-Agnostic Three-Stage Sleep Classification Using Wearable Sensing Data

Long-term non-invasive sleep stage monitoring is instrumental in comprehending the progression of sleep disorders, cardiovascular diseases, and the interplay between sleep, type 2 diabetes, and neurodegenerative diseases. However, the conventional deep learning approach is susceptible to personal attributes (PAs) such as age, Body Mass Index, and severity of sleep apnea existing in the training dataset, potentially hindering its generalisation capacity to unseen cohorts. This paper introduces DSleepNet, a novel approach that disentangles the feature space into PA-specific and PA-agnostic components using two probabilistic encoders. The PA-agnostic features, designed to remain unaffected by personal attributes, outperformed the baseline CNN, improving the mean F1 score by up to 8.7% (baseline: 60.3) and Cohen's Kappa by 4.7% (baseline: 55.5), especially in reducing the impact of sleep apnea. DSleepNet functions without the need for target cohort data during training. It operates without the need to acquire PA data during inference, nor does it require fine-tuning. A novel Independent Excitation mechanism is incorporated into the latent feature space to remove correlations between the two types of features. Comprehensive testing in various PA settings has demonstrated its efficacy in improving the model's robustness.