Sleep quality is closely related to human health. It is very important to correctly discriminate the sleep stages for evaluating sleep quality, diagnosing and analyzing the sleep-related disorders. Polysomnography (PSG) signals are commonly used to record and analyze sleep stages. Effective feature extraction and representation is one of the most important steps to improve the performance of sleep stage classification. In this work, a collaborative representation (CR) algorithm was adopted to re-represent the original extracted features from electroencephalogram sig- nal, and then the kernel entropy component analysis (KECA) algorithm was further used to reduce the feature dimension of CR-feature. To evaluate the performance of CR-KECA, we compared the original feature, CR feature and readied CR feature (CR-PCA) after principal component analysis (PCA). The experimental results of sleep stage classification indicated that the CR-KECA method achieved the best performance compared with the original feature, CR feature, and CR-PCA feature with the classification accuracy of 68.74 +/- 0.46%, sensitivity of 68.76 +/- 0.43% and specificity of 92.19 +/- 0.11%. Moreover, CR algorithm had low computational complexity, and the feature dimension after KECA was much smaller, which made CR-KECA algorithm suitable for the analysis of large-scale sleep data.
Algorithms ; Electroencephalography ; Entropy ; Humans ; Polysomnography ; Principal Component Analysis ; Sleep Stages ; Sleep Wake Disorders ; diagnosis ; Software

Objective:To summarize the thinking and compatibility law of TCM in the treatment of stable angina pectoris (SAP) based on syndrome differentiation using data mining technology.Methods:The clinical studies of TCM treatment for SAP in databases of CNKI, Wanfang Data, VIP and SinoMed China Biomedical Literature Service System were retrieved from the establishment of the databases to February 28, 2022. The frequency statistic, clustering analysis and association rule analysis of TCM data were conducted using Clementine 12.0, Excel 2016, SPSS Statistics 22.0 software, and core prescriptions were summarized.Results:Totally 289 prescriptions were included, involving 185 kinds of Chinese materia medica, including 38 TCM syndrome types. Based on the overall study of SAP "disease", the clinical treatment of SAP was mainly based on the drugs for activating blood circulation and removing blood stasis, tonifying deficiency and strengthening healthy qi, and regulating qi and resolving phlegm. The single Chinese materia medica with high frequency of use were Chuanxiaong Rhizoma, Salviea Miltiorrhizae Radix et Rhizoma, Glycyrrhizae Radix et Rhizoma, Angelicae Sinensis Radix, Angelicae Sinensis Radix, etc. The commonly used drug pairs included Chuanxiaong Rhizoma-Angelicae Sinensis Radix, Chuanxiaong Rhizoma-Carthami Flos, Chuanxiaong Rhizoma-Aurantii Fructus Immaturus, etc. The drug complex network diagram and clustering analysis showed that the prescription of Buyang Huanwu Decoction was the basic prescription for the treatment of SAP; based on the specific research of SAP "syndrome", the most common TCM syndromes of SAP were qi deficiency and blood stasis, phlegm and blood stasis, and qi stagnation and blood stasis. The drug properties of the three drugs were mainly warm and mild; the tastes were mainly sweet, pungent and bitter, and most of them belong to the liver, spleen, lung and heart meridian; in terms of specific medication, the basic prescription of qi deficiency and blood stasis syndrome was Buyang Huanwu Decoction, which was composed of high-frequency drugs such as Angelicae Sinensis Radix, Chuanxiaong Rhizoma, Salviea Miltiorrhizae Radix et Rhizoma, etc; The phlegm and blood stasis syndrome was often based on the Gualou Xiebai Banxia Decoction and Taohong Siwu Decoction, which were composed of high frequency drugs such as Pinelliae Rhizoma, Chuanxiaong Rhizoma, Allii Macrostemonis Bulbus, etc; the basic prescription of qi stagnation and blood stasis syndrome was Xuefu Zhuyu Decoction, which was composed of high frequency drugs such as Chuanxiaong Rhizoma, Angelicae Sinensis Radix, Aurantii Fructus. Drug clustering analysis showed that both qi deficiency and blood stasis syndrome and qi stagnation and blood stasis syndrome were divided into 3 categories, and phlegm and blood stasis syndrome were divided into 4 categories.Conclusions:Deficiency, blood stasis, phlegm and stagnation are important pathological factors of SAP, in which qi deficiency is the basis of SAP, blood stasis runs through the disease, or both phlegm and qi stagnation. Focusing on the pathogenesis of deficiency in root and excess in superficiality, drugs with the efficacy of tonifying the deficiency and promoting blood circulation and removing blood stasis are used in clinical treatment, according to different syndrome differentiation of prescription selection.