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find Author "ZHANG Junpeng" 3 results
  • Research on cortical cross-modal reorganization of children with congenital severe deafness after cochlear implant

    Cochlear implant (CI) is the only method for efficacious treatment of congenital severe deafness at present. However, for children with congenital severe deafness after CI, the mechanism of the structural and functional changes of their cerebral cortex is not clear. This study was based on the cross-modal reorganization of deaf patients. Event related potential (ERP) and source localization technique were used to visualize the change of cortical activity in children with congenital severe deafness during 1-year period (0, 1, 3, 6, 9 and 12 months after CI). We aimed to investigate the association between hearing restoration and cross-modal reorganization in children with congenital severe deafness after CI. The results showed that the cross-modal reorganization exists in children with congenital severe deafness. During hearing restoration, the function of the cross-modal reorganization reversed to the normal state. The method and conclusions of this study may be of significance in guiding the training and evaluation of hearing rehabilitation after CI in patients.

    Release date:2017-10-23 02:15 Export PDF Favorites Scan
  • Magnitude image-guided phase unwrapping algorithm of susceptibility weighted images

    To better use the phase information to compensate the influence of blood flow, the phase unwrapping problem in susceptibility weighted imaging (SWI) is studied in this paper. In order to improve the accuracy of unwrapping, this paper proposes a magnitude image-guided phase unwrapping algorithm of SWI. The basic idea is as follows: (1) reduce the influence of noise by improving the rotational invariant non-local principal component analysis method (PRI-NL-PCA); (2) extract the corresponding solid region in the phase image to avoid the influence of the background noise on the phase unwrapping method; (3) use the phase compensation method to constrain the phase image reconstructed by the K-space. Finally, the reliability of the unwrapping method is evaluated by using four kinds of statistics as quantification index: the number, mean (M), variance (Var), and positive percentage (Pos) and negative percentage (Neg) of phasic error points. By comparing the simulated data with 226 sets of true head SWI data, the results show that the proposed algorithm has high accuracy compared with the classical branch cut method and the least squares method.

    Release date:2017-10-23 02:15 Export PDF Favorites Scan
  • Resting-state electroencephalogram classification of patients with schizophrenia or depression

    The clinical manifestations of patients with schizophrenia and patients with depression not only have a certain similarity, but also change with the patient's mood, and thus lead to misdiagnosis in clinical diagnosis. Electroencephalogram (EEG) analysis provides an important reference and objective basis for accurate differentiation and diagnosis between patients with schizophrenia and patients with depression. In order to solve the problem of misdiagnosis between patients with schizophrenia and patients with depression, and to improve the accuracy of the classification and diagnosis of these two diseases, in this study we extracted the resting-state EEG features from 100 patients with depression and 100 patients with schizophrenia, including information entropy, sample entropy and approximate entropy, statistical properties feature and relative power spectral density (rPSD) of each EEG rhythm (δ, θ, α, β). Then feature vectors were formed to classify these two types of patients using the support vector machine (SVM) and the naive Bayes (NB) classifier. Experimental results indicate that: ① The rPSD feature vector P performs the best in classification, achieving an average accuracy of 84.2% and a highest accuracy of 86.3%; ② The accuracy of SVM is obviously better than that of NB; ③ For the rPSD of each rhythm, the β rhythm performs the best with the highest accuracy of 76%; ④ Electrodes with large feature weight are mainly concentrated in the frontal lobe and parietal lobe. The results of this study indicate that the rPSD feature vector P in conjunction with SVM can effectively distinguish depression and schizophrenia, and can also play an auxiliary role in the relevant clinical diagnosis.

    Release date:2020-02-18 09:21 Export PDF Favorites Scan
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