Research progress on pretreatment technology for the analysis of amphetamine biological samples.

Sample pretreatment technology is crucial for drug analysis and detection, because the effect of sample pretreatment directly determinates the final analysis results. In recent years, with the continuous innovation of microextraction and other technologies like material preparation technologies and assistant technologies for extraction, the sample pretreatment techniques in the process of drug analysis have become more and more mature and diverse. This article takes amphetamine (AM) or methamphetamine as an example to review the recent development of pretreatment methods for AM-containing biological samples from the perspectives of extraction techniques, extraction media and auxiliary technologies.

[An algorithm study on telecardiogram diagnosis based on multivariate autoregressive model and two-lead ECG signals].

Objective: In view of the time delay caused by reconstruction of signals at remote sites, a direct classification method with high accuracy suitable for telediagnosis of electrocardiogram (ECG) signals is studied.

Method: The data for analysis and classification was obtained from MIT-BIH database, including 300 samples each of normal sinus rhythm (NSR), atria premature contraction (APC), premature ventricular contraction (PVC), ventricular tachycardia (VT), ventricular fibrillation (VF) and superventricular tachycardia (SVT). An multivariate autoregressive (MAR) model based technique that could combine the signals of two ECG leads was presented to classify the ECGs directly, including MAR modeling performed on ECGs, and quadratic discrimination function (QDF) based classification by using MAR coefficients and K-L MAR coefficients.