RESUMEN
As an important promising biomarker, high frequency oscillations (HFOs) can be used to track epileptic activity and localize epileptogenic zones. However, visual marking of HFOs from a large amount of intracranial electroencephalogram (iEEG) data requires a great deal of time and effort from researchers, and is also very dependent on visual features and easily influenced by subjective factors. Therefore, we proposed an automatic epileptic HFO detection method based on visual features and non-intuitive multi-domain features. To eliminate the interference of continuous oscillatory activity in detected sporadic short HFO events, the iEEG signals adjacent to the detected events were set as the neighboring environmental range while the number of oscillations and the peak–valley differences were calculated as the environmental reference features. The proposed method was developed as a MatLab-based HFO detector to automatically detect HFOs in multi-channel, long-distance iEEG signals. The performance of our detector was evaluated on iEEG recordings from epileptic mice and patients with intractable epilepsy. More than 90% of the HFO events detected by this method were confirmed by experts, while the average missed-detection rate was < 10%. Compared with recent related research, the proposed method achieved a synchronous improvement of sensitivity and specificity, and a balance between low false-alarm rate and high detection rate. Detection results demonstrated that the proposed method performs well in sensitivity, specificity, and precision. As an auxiliary tool, our detector can greatly improve the efficiency of clinical experts in inspecting HFO events during the diagnosis and treatment of epilepsy.
RESUMEN
Objective To explore a separation and culture method of human adipose-derived stem cells(ADSCs) suitable for the clinical application .Methods The non-enzymatic method and the collagenase digestion method were adopted to isolate and culture the cells from the human adipose tissue in the individuals with liposuction .The characteristics of isolated mesenchymal stem cells were comparatively analyzed .Results The required time in the non-enzymatic method was one third of that in the collagenase di-gestion method and the cellular morphology ,reproductive capacity ,immunophenotype and differentiation potential of the isolated cells were consistent to those isolated by the collagenase digestion method .Conclusion The no-enzymatic method may isolate and culture ADSCs from the adipose tissue in the individual with liposuction ,which is a safety and reliable isolation and culture method of human adipose tissue-derived stem cells suitable for clinical application .