| 研究生: |
郭至恩 Kuo, Chih-En |
|---|---|
| 論文名稱: |
開發一套基於單通道睡眠生理訊號的自動睡眠判讀系統與其在睡眠環境控制上之應用 Development of Automatic Sleep Staging Methods for Single-channel Sleep Recordings and Their Related Applications in Sleep Environmental Control |
| 指導教授: |
梁勝富
Liang, Sheng-Fu |
| 學位類別: |
博士 Doctor |
| 系所名稱: |
電機資訊學院 - 資訊工程學系 Department of Computer Science and Information Engineering |
| 論文出版年: | 2013 |
| 畢業學年度: | 101 |
| 語文別: | 英文 |
| 論文頁數: | 85 |
| 中文關鍵詞: | 睡眠自動判讀 、腦電訊號 、眼動電訊號 、睡眠監測 、睡眠環境控制 |
| 外文關鍵詞: | Automatic sleep staging, electroencephalogram (EEG), electrooculogram (EOG), sleep monitoring, sleep environmental corntrol |
| 相關次數: | 點閱:175 下載:6 |
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許多人被睡眠疾病與相關問題所困擾。目前臨床睡眠診斷上主要使用PSG所收錄的電生理訊號作為專家來判讀睡眠階段的依據。然而,專家判讀需要耗費許多人力與時間且受專家個人主觀上的影響,所以很多基於多通道睡眠生理訊號的自動睡眠判讀系統已被開發。可是收錄多重生理訊號有很多缺點,如大量的電極線對於使用者造成睡眠干擾與無法獨立使用等問題。腦電訊號是臨床的睡眠判讀法則中主要的判讀依據。因此我們先開發了一套基於單通道腦電訊號的自動睡眠判讀系統。我們使用多尺度熵與自迴歸模型參數來分析32位健康的成年人的整夜睡眠時的腦電訊號,並運用線性分類器進行睡眠階段分類。我們也針對睡眠週期的連續性和睡眠階段的限制,考慮前後週期所擁有的資訊,將線性分類器判斷後的結果再做平滑化處理以得到最後自動睡眠判讀的結果。本系統的判讀結果與專家判讀結果相比,整體一致性與kappa係數可以達到87.15%和0.81,這效能亦優於目前臨床判讀的標準。
相較於腦電訊號,眼動訊號只需在眼部周圍黏貼電極,並且也能擷取到某些睡眠腦電訊號的特徵。因此眼動訊號兼具居家使用的便利性與可應用於睡眠階段判讀的優點。為了適用於居家照顧,我們再開發出一個基於單通道睡眠眼動訊號的自動睡眠判讀系統。除了多尺度熵與自迴歸模型參數,我們也提出了一個新的特徵-多尺度線段長度,來提升快速眼動期的準確率。經過同樣32位受試者的整晚眼動訊號的分析與測試,本系統的判讀結果與專家判讀結果相比,整體一致性與kappa係數可以達到83.33%和0.75。這效能是目前只使用睡眠眼動訊號的自動判讀方法中最好的。因此我們把這套自動判讀方法再延伸到居家睡眠環境控制的應用上。
在本論文的附錄中,我們亦展示了我們的自動睡眠判讀方法的可應用性。近年來,有很多評估使用者睡眠品質或監測睡眠環境的系統被開發。然而,目前依據使用者的睡眠期來主動改變睡眠環境,以幫助使用者擁有更好的睡眠品質之產品與方法非常稀少。燈光是睡眠環境中的主要因素,因此我們結合單通道眼動電訊號的自動睡眠判讀方法以及根據使用者的睡眠期來調整燈光強度的演算法來開發一套閉迴路人機界面系統。經由3位受測者的測試結果,證實以我們的系統來控制睡眠環境燈光的可行性。我們未來將會考慮更多睡眠環境的因素來幫助使用者擁有健康、舒適與安全的睡眠品質與環境。
此外,許多研究指出睡眠與記憶鞏固或學習效益提升非常的相關。但是這些相關實驗的步驟往往需要專家與實驗人員整晚長時間的監控,造成許多的人力與時間的耗費。未來我們也會把我們的方法應用於睡眠與記憶鞏固或學習效益提升等相關實驗的自動化上,以節省更多的人力與時間成本。
Sleep diseases, such as insomnia and obstructive sleep apnea, seriously affect patients’ quality of life. For diagnosis, polysomnographic (PSG) recordings are most usually taken for sleep stage scoring. However, manual scored by well-trained expert which is a time-consuming and subjective process. Many multi-channel-based automatic sleep staging methods have been developed. These approaches have many drawbacks. For example, the large amount of wires connections for conventional PSG often cause sleep interference and not self-applicable. Sleep EEG signals is the main basis of the manual sleep scoring rules in clinical diagnosis. Therefore, we develop an automatic sleep staging method based on single-channel sleep EEG signals. We utilize multiscale entropy and autoregressive model coefficients to analyze the 32 all-night sleep EEG recordings from 32 healthy adult and the linear discriminant analysis (LDA) was utilized to classify each epoch into five sleep stages. After classifying the sleep stage by LDA, some misclassified epochs can be corrected according to the temporal contextual information. We utilize the smoothing process to smooth and fine-tune the results of the classifier. The average accuracy and kappa coefficient of the proposed method applied to 16 all-night (PSG) recordings compared with the manual scorings can reach 87.15 % and 0.81, respectively. The results are also better than the range in the inter-score agreement.
Compared to EEG, electrodes placement of EOG recording is around the eyes, and EOG signals are also coupling some of sleep characteristics of EEG signals. Therefore, EOG has the ease of use in the home and can be applied to sleep scoring. For the applicability of home care, we also develop an automatic sleep staging method based on single-channel sleep EOG signals. In addition to multiscale entropy and autoregressive model coefficients, we also propose a new feature, multiscale line length, to enhance the sensitivity of rapid eye movement (REM) stage. The average accuracy and kappa coefficient of the proposed method compared with the manual scorings can reach 83.33 % and 0.75, respectively. The performance of our proposed method is the best in currently automatic sleep staging methods based on single-channel sleep EOG signals. So we extend the automatic sleep staging method to the application of sleep environmental control at home.
In the appendix, we also show the applicability of our automatic sleep scoring method. Recently, many systems or products to support healthy sleep by monitoring the sleep environment or users’ activities and sleep quality have been developed. However, actively on-line adjusting conditions of the sleep environment according to sleep stages of the user are rare. Light is the main factor in sleep environment. We use our proposed sleep scoring method combined with a light-control algorithm based on sleep stage to develop a closed-loop human–computer interaction (HCI) system. With the experimental results of three subjects, the feasibility of controlling the light in sleep environments is demonstrated. In the future, we will consider more sleep environmental factors for the healthy, comfortable and safe sleep quality and environment.
In addition, many previous studies had pointed out that sleep and memory consolidation, learning, or performance improvement is very relevant. However, these related experiments often require experts and laboratory personnel to monitor all night, it takes a lot of manpower and time-consuming. To save more time and manpower costs, we will apply our method to related studies and experiments for automation in the future.
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