Inter-patient arrhythmia ECG signal classification based on SVM+XGBoost ensemble classifier / 国际生物医学工程杂志

Objective:To study a classifier used to classify arrhythmia electrocardiogram (ECG) signals under the inter-patient paradigm to improve the accuracy of automatic classification and solve the limitations of manual diagnosis of arrhythmia.Methods:A SVM+XGBoost ensemble classifier with four modules including preprocessing, feature extraction, support vector machine (SVM) training and ensemble classification was constructed. ECG signal was preprocessed, and R-R interval, high-order statistics, local binary patterns and wavelet components were used as features to train independent SVM classifiers. Then, XGboost algorithm was used to integrate independent SVM classifiers and output arrhythmia classification results. The integrated classifiers were trained and tested on MIT-BIH database.Results:The overall classification accuracy of the ensemble classifier for arrhythmia was 0.867 and the average sensitivity was 0.782.Conclusions:The proposed ensemble classifier can realize automatic and accurate classification of arrhythmia ECG signals under the inter-patient paradigm, and can be used for clinical auxiliary diagnosis.

Effects of valsartan on nuclear factor-?B protein expression in the kidney of spontaneously hypertensive rats / 中国临床药理学与治疗学

AIM: To observe the local expression of nuclear factor-?B(NF-?B) in spontaneously hypertensive rat(SHR) kidney and effects of AT1 receptor contagonist valsartan.METHODS: 16 SHRs were randomly divided into two groups: SHR control group and valsartan group.Another 8 WKY rats act as normal control group.Systolic blood pressure(SBP) of SHR was measured at the beginning and the end of 2,4,6 and 8 weeks of intervention treatment.Radioimmunoassay was used to determine the activities of rennin and angiotensin II(AngII).The renal tissue NF-?B protein expression was detected by immunobiochemistry.RESULTS: SBP of SHR was remarkably decreased after valsartan intervention.However,the rennin activities and AngII level in plasma increased in valsartan group.In the renal tissue of SHR,there was remarkably increased in expression of NF-?B protein.Valsartan could significantly reduced NF-?B expression.CONCLUSION: Valsartan can depress NF-?B renal expression in protein level and might benefit hypotension renal function.