2020

Yan, Rui

Over the past decades, probably due to our hectic lifestyle in modern society, complaints about sleep problems have increased dramatically, affecting a large part of the world’s population. The polysomnography (PSG) test is a common tool for diagnosing sleep problems, but the scoring of PSG recordings is an essential but time-consuming process. Therefore, automatic sleep scoring becomes crucial and urgent to settle the growing unmet needs in sleep research. This thesis extends the previous research on automatic sleep scoring from two aspects. One is to extensively explore signal modalities and feature types related to automatic sleep scoring. This exploratory work obtains the optimal signal fusion and feature set for automatic sleep scoring, and further clarifies the contribution of signals and features to the discrimination of sleep stages. Our results demonstrate that diverse features and signal modalities are coordinative and complementary, which benefits the improvement of classification accuracy. The other one is to develop automatic sleep scoring tools that can accommodate different datasets and sample populations without adjusting model structure and parameters across tasks. Experimental results show that the joint analysis of multiple signals can improve the stability, robustness and generalizability of the proposed models. Model performance has been verified on multiple public datasets, demonstrating good model transferability between different datasets and diverse disease populations. In summary, this research finding will advance the understanding of underlying mechanism during automatic sleep scoring and clarify the association between manual scoring criteria and automatic scoring methods. The joint analysis of multiple signals enhances model versatility, which inspires the construction of cross-model in the field of automatic sleep scoring. Moreover, the proposed automatic sleep scoring methods can be integrated with diverse PSG systems, thereby facilitating sleep monitoring in clinical or routine care.