1.Application of pulse-coupled neural network combined with genetic algorithm on MR images of hypoxic-ischemic encephalopathy.
Li LIU ; Haiying SHI ; Liqin HUO ; Feng ZHANG ; Chongxun ZHENG ; Jia YOU ; Xining HE ; Jie ZHANG
Journal of Biomedical Engineering 2011;28(5):1019-1024
This paper is to provide a basis for the establishment of an early diagnostic system for hypoxic-ischemic encephalopathy (HIE) by performing segmentation and feature extraction of lesions on the MR images of neonatal babies with HIE. The segmentation on MR images of HIE based on the genetic algorithm (GA) combined with a pulse-coupled neural network (PCNN) were carried out. There were better segmentation results by using PCNN segmentation based on GA than PCNN segmentation with fixed parameters. The data suggested that a PCNN based on GA could provide effective assistance for diagnosis and research.
Algorithms
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Female
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Humans
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Hypoxia-Ischemia, Brain
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diagnosis
;
physiopathology
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Image Processing, Computer-Assisted
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Infant, Newborn
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Magnetic Resonance Imaging
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methods
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Male
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Neural Networks (Computer)
2.The study on the early diagnosis of hypoxic ischemic encephalopathy (HIE) in the newborns by fuzzy BP neural networks.
Li LIU ; Liqin HUO ; Feng ZHANG ; Chongxun ZHENG ; Jia YOU ; Xining HE ; Jie ZHANG
Journal of Biomedical Engineering 2011;28(4):814-829
This paper is aimed to study a method and feasibility of early diagnostic system using hypoxic ischemic encephalopathy (HIE) in the newborns. Fifteen non-invasive indicators with high sensitivity and specificity were selected for the early diagnosis of HIE on the basis of related researches from the literature and the researches in our laboratory. The diagnostic test was done with 140 cases with the HIE, using the fussy BP neural network experiment system. The initial results showed that the accuracy rate was 100% for the training set and 95% for the testing set, and the error rate was 5%. The data suggested that the fuzzy back-propagation neural networks, with the clinical comprehensive indicators, exhibited a high accuracy for the early diagnosis of HIE. This method provides an objective and convenient new way for the early clinical diagnosis of the HIE.
Algorithms
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Diagnosis, Computer-Assisted
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methods
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Early Diagnosis
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Female
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Fuzzy Logic
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Humans
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Hypoxia-Ischemia, Brain
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diagnosis
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Infant, Newborn
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Male
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Neural Networks (Computer)
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Pattern Recognition, Automated
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methods
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Reproducibility of Results
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Sensitivity and Specificity
3.Identification of mentality facticity based on multi-channel event-related potentials.
Min ZHAO ; Chongxun ZHENG ; Chunlin ZHAO ; Jianping LIN
Journal of Biomedical Engineering 2010;27(3):641-646
This paper explores the use of multi-channel event-related potentials (ERP) to identify mentality facticity or detect lie. Some identifiably meaning information, such as subjects' name and birthday, were selected as concealed information to be identified, 15 subjects were tested by concealed information test (CIT) paradigm and their electroencephalographs (EEG) were recorded from 30 electrodes. In virtue of analysis on the statistically significant difference between multi-channel ERPs evoked by probe information and that evoked by irrelevant information, the P300 amplitudes of 15 electrodes were selected as F-test samples. The significant difference of feature sample values between probe and irrelevant information was applied to identify mentality facticity. The results indicate that P300 amplitudes evoked in many electrodes are significantly different between probe and irrelevant information (P < 0.01). According to the significant difference of space sample values between probe and irrelevant information, the detection correctness to probe information reaches to 93.3% and is better than that of methods based single-channel ERP. The method proposed has the advantages of non-invasion and better accuracy, which could be used to identify mentality facticity effectively.
Adult
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Electroencephalography
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methods
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Event-Related Potentials, P300
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physiology
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Female
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Humans
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Lie Detection
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psychology
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Male
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Neuropsychological Tests
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Young Adult
4.Power spectrum analysis on the multiparameter electroencephalogram features of physiological mental fatigue.
Chong ZHANG ; Chongxun ZHENG ; Xiaomei PEI ; Yi OUYANG
Journal of Biomedical Engineering 2009;26(1):162-172
The aim of this experiment is to find a feasible impersonal index for analyzing the physiological mental fatigue level. Three characteristic parameters, relative power in different rhythm, barycenter frequency and power spectral entropy, are extracted from two channels' electroencephalogram (EEG) under two physiological mental fatigue states. Then relationships between such three parameters and physiological mental fatigue are analyzed to explore whether they can be of use for detecting (or monitoring) the mental fatigue level. The experiment results show that the relative power, barycenter frequency and power spectral entropy of EEG exhibit strong correlation with physiological mental fatigue level. While physiological mental fatigue level increases, the relative power in theta, alpha and beta rhythms, barycenter frequency and power spectral entropy of EEG decrease, but the relative power in delta rhythm of EEG increases. The relative power in four rhythms, barycenter frequency and power spectral entropy of EEG reflect the change of physiological mental fatigue level sensitively, and may hopefully be used as indexes for detecting physiological mental fatigue level.
Adult
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Electroencephalography
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Entropy
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Humans
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Male
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Mental Fatigue
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physiopathology
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Signal Processing, Computer-Assisted
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Young Adult
5.A water-fat separation imaging method for the brain on low field magnetic resonance imaging
Hongjun TIAN ; Siping CHEN ; Tianfu WANG ; Xianfen DIAO ; Chongxun ZHENG
Journal of Pharmaceutical Analysis 2009;21(4):272-276
Water-fat separation is a particularly important problem for magnetic resonance imaging. Although many methods have been proposed, the reliability is still challenging. In this work, we have presented a method based on the combination of the branch-cut method and multigrid algorithm to get a more robust performance of water-fat separation. First, the branch-cut method is applied to identify residues, which violates the requirement that the interacting phase gradient around a closed path be zero. Residues and branches are marked to be zeros and filled to the weighting factor array. Then, the unwrapped phase array can be given by the multigrid algorithm. Finally, the Dixon method for water-fat separation is applied to the unwrapped phase array. Experiments for brain scanning on the 0.3T low field MRI system demonstrate the successful application of the proposed method.
6.Study of dopamine transporter imaging on the brain of children with autism.
Xiaomian SUN ; Jing YUE ; Chongxun ZHENG
Journal of Biomedical Engineering 2008;25(2):327-330
This study was conducted to evaluate the applicability of 99mTc-2beta-[ N, N'-bis (2-mercaptoethyl) ethylenediamino]methyl,3beta(4-chlorophenyl)tropane(TRODAT-1) dopamine transporter(DAT) SPECT imaging in children with autism, and thus to provide an academic basis for the etiology, mechanism and clinical therapy of autism. Ten autistic children and ten healthy controls were examined with 99mTc-TRODAT-1 DAT SPECT imaging. Striatal specific uptake of 99mTc-TRODAT-1 was calculated with region of interest analysis according to the ratics between striatum and cerebellum [(STR-BKG)/BKG]. There was no statistically significant difference in semiquantitative dopamine transporter between the bilateral striata of autistic children (P=0.562), and between those of normal controls (p=0.573); Dopamine transporter in the brain of patients with autism increased significantly as compared with that in the brain of normal controls (P=0.017). Dopaminergic nervous system is dysfunctioning in the brain of children with autism, and DAT 99mTc-TRODAT-1 SPECT imaging on the brain will help the imaging diagnosis of childhcod autism.
Autistic Disorder
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diagnostic imaging
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metabolism
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Brain
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diagnostic imaging
;
metabolism
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Child
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Child, Preschool
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Dopamine Plasma Membrane Transport Proteins
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metabolism
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Humans
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Male
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Organotechnetium Compounds
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Tomography, Emission-Computed, Single-Photon
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Tropanes
7.Spectral entropy analysis of different alpha band rhythms in relation to hand motor imagery
Xiaomei PEI ; Chongxun ZHENG ; Renhou LI
Journal of Pharmaceutical Analysis 2008;20(3):202-205
The event-related desynchronization/synchronization(ERD/ERS) time courses of lower and upper alpha band rhythms during hand motor imagery are investigated respectively by Fourier Sectral Entropy (FSE) in this paper. By analyzing one group of BCI competition data, it was found that FSE within upper alpha band displays a pronounced increase and decrease over contralateral and ipsilaterai brain areas respectively at the onset of hand motor imagery, which is corresponding to the antagonistic ERD/ERS patterns in previous studies. Different from the upper alpha activity pattern, FSE within lower alpha band displays a consistent increase over both two hemispheres hand representative areas. The preliminary results show that FSE could disclose the different behaviors of the upper and lower alpha band rhythms so that a new idea with the complexity measure is provided to characterize functional dissociation of lower and upper frequency alpha rhythms in relation to hand motor imagery.
8.Multiple mental tasks classification based on nonlinear parameter of mean period using support vector machines
Hailong LIU ; Jue WANG ; Chongxun ZHENG
Journal of Pharmaceutical Analysis 2007;19(1):70-72
Mental task classification is one of the most important problems in Brain-computer interface. This paper studies the classification of five-class mental tasks. The nonlinear parameter of mean period obtained from frequency domain information was used as features for classification implemented by using the method of SVM (support vector machines). The averaged classification accuracy of 85.6% over 7 subjects was achieved for 2-second EEG segments. And the results for EEG segments of 0.5s and 5.0s compared favorably to those of Garrett's. The results indicate that the parameter of mean period represents mental tasks well for classification. Furthermore, the method of mean period is less computationally demanding, which indicates its potential use for online BCI systems.
9.Effects of rhubarb extracts on hyperexcitability of hippocampal CA1 neurons after fluid percussion injury
Aihua ZHANG ; Jianwen GU ; Chongxun ZHENG ; Xiaomei PEI
Journal of Pharmaceutical Analysis 2007;19(1):73-76,100
Objective To investigate the effects of rhubarb extracts, i.e. rhein and emodin, on the neuronal hyperexcitability and synaptic transmission, and to further reveal the mechanism of the secondary brain damage. Methods The fluid percussion injury (FPI) rat model and extracellular recording method were used. The evoked field potentials by stimulating Schaffer collaterals were collected from the ipsilateral (impact side) and the contralateral hippocampal CA1 areas of rat in vitro. And the field potentials, including the field excitatory postsynaptic potential and the population spike, were analyzed. Results After the impact was performed on the rat parietal cortex, the evoked field potentials in the ipsilateral hippocampus CA1 area were enhanced obviously. Rhubarb extracts reduced the slope of the field excitatory postsynaptic potential and the number of the population spike significantly while rhein and emodin increased the latency of the population spike obviously. Conclusion Rhubarb extracts, i.e. rhein and emodin, can depress the neuronal hyperexcitability, which suggests that rhein and emodin play an important role in protecting the central nervous system from neuronal damage after traumatic brain injury. FPI produces hyperexcitability of hippocampal CA1 neurons, probably by enhancing excitatory synaptic transmission.
10.Monitoring on Depth of Anesthesia Basing on ? Rhythm Autocorrelation of EEG Signals
Space Medicine & Medical Engineering 2006;0(04):-
Objective To explore the relationship between the depth of anesthesia and the autocorrelation of spontaneous EEG signals,and to find a new indicator which is easily calculated and involves fewer channels of ECG.Methods Eighteen patients with a surgical operation on chest or abdomen under general anesthesia served as the subjects.EEG signals of the patients were recorded.Change of ? rhythm of the EEG signal during general anesthesia was investigated by autocorrelation.Results The changes of autocorrelation indicator in channels Fp1-Cz and Fp2-Cz were obvious and consistent with the process of anesthesia;The changes of autocorrelation kcr in the two observed channels were almost synchronous.Conclusion The autocorrelation indicator kcr may be a new idea and a new tool for monitoring depth of anesthesia with fewer channels and the method will find wide prospect of application in clinic and in related scientific research work.
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