Visual and automatic classification of the cyclic alternating pattern in electroencephalography during sleep

Cyclic alternating pattern (CAP) is a neurophysiological pattern that can be visually scored by international criteria. The aim of this study was to verify the feasibility of visual CAP scoring using only one channel of sleep electroencephalogram (EEG) to evaluate the inter-scorer agreement in a variety of recordings, and to compare agreement between visual scoring and automatic scoring systems. Sixteen hours of single-channel European data format recordings from four different sleep laboratories with either C4-A1 or C3-A2 channels and with different sampling frequencies were used in this study. Seven independent scorers applied visual scoring according to international criteria. Two automatic blind scorings were also evaluated. Event-based inter-scorer agreement analysis was performed. The pairwise inter-scorer agreement (PWISA) was between 55.5 and 84.3%. The average PWISA was above 60% for all scorers and the global average was 69.9%. Automatic scoring systems showed similar results to those of visual scoring. The study showed that CAP could be scored using only one EEG channel. Therefore, CAP scoring might also be integrated in sleep scoring features and automatic scoring systems having similar performances to visual sleep scoring systems.

Study on the automatic analysis of dicentric chromosome biodosimetry / 中华放射医学与防护杂志

Objective To investigate a dose response curve based on a genetic workstation with automatic analysis system of dicentric chromosome assay (DCA) for establishing a high speed dose estimation method.Methods Peripheral blood from three healthy volunteers was irradiated in vitro using 60Co γ-rays,and then lymphocytes were cultured and fixed on slides using the standard protocol for DCA.Dicentric chromosome in metaphase cells was analyzed automatically with the genetic workstation and confirmed manually,and the dose response curve of automated dicentric chromosome was fitted.Dicentric chromosome of another peripheral blood sample irradiated with different doses was manually analyzed to verify the accuracy of the above automated DCA.Results The yield of automated DCA was well fitted by an equation Y =0.018 06D2 + 0.012 79D + 0.000 489 1 with a correlation coefficient R2 =0.961.The biological dose of radiation could be accurately estimated by this dose response curve within a few minutes.Conclusions We had successfully established a new dosimetry method by analyzing dicentric chromesome automatically,which can save a lot of manual analysis time and hence has important significance for emergency rescue in nuclear accidents.