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2014 Vol. 33, No. 5
Published: 2014-10-20
 
513
Image Edge Detection Based on Spike Coding of Multilayer Neuronal Population with Inhibitory Synapse
Image Edge Detection Based on Spike Coding of Multilayer Neuronal Population with Inhibitory Synapse[J]. journal1, 2014,33(5): 513-524')" href="#"> LIAO Jin Wen  FAN Ying Le*WU Wei  Gao Yun Yuan  LI Yi
DOI: 10.3969/j.issn.0258-8021.2014.05.01
Details of objects’ contour can be acquired from the edge detection, which are considered important for image analysis and understanding correctly. In this paper, a new method for image edge detection was proposed based on vision mechanism. Multilayer neuronal population with inhibitory synapse was constructed to receive the stimuli from an awaited image, and the process of pulse spiking from connected neurons in the 7×7 window of visual receptive field was analyzed, spiking times were recorded for rank coding.Considering the effect of lateral inhibition between neurons, images with the mechanism of selective attention were enhanced; then LogGabor filter was adopted to stimulate the orientation selectivity of visual system for obtaining the filtering results of 8 orientations, the edge map could be acquired through integration processing of the output neuron layer and gray mapping to the range between 0 and 255. Taken the colony images with abundant edge details for processing, the mean value of ROC index for the results was 0698 4, better than that of PCNN, which was 0659 3; the results of the new method were better in the view of consistency in terms of the mean square deviation. Additionally, the new method also owning certain advantages in terms of information entropy, indicating the method proposed could extract edge information effectively and reflect image details in more levels. The method of edge detection proposed in the paper provides a new and effective idea for the image processing based on visual physiological characteristics.
2014 Vol. 33 (5): 513-524 [Abstract] ( 245 ) HTML (1 KB)  PDF (2871 KB)  ( 632 )
525 Automatic Brain Extraction Method from Cerebral MRI Image Based on GraphCuts
YANG Su Hua*   CHEN Qiong   LUO Yan Fen
DOI: 10.3969/j.issn.0258-8021.2014.05.02
The brain extraction from cerebral T1 weighted MRI volume is an important preprocedure for neuroimage analysis. To improve the precision of extraction, an automatic brain extraction method based on a graphcuts model was proposed. The method uses the brain extraction tool (BET) to obtain the region of interest (ROI) and only performs graphcuts model in the ROI. A velocity factor was added in the graphcuts model to eliminate the boundary leakage and local convergence. A slice by slice contour initial method was also used to initialize the 3D brain boundary. The method was applied to 18 cerebral MRI volumes provided by the Internet Brain Segmentation Repository (IBSR). In testing, the mean Dice similarity coefficient was 095 and the results obtained by our method were very similar to those produced by manual segmentation and achieved the best results on many of the evaluation metrics (false positives rate 32% and Hausdorff distance 96) for the IBSR data in comparison of our method with existing brain extraction methods including brain extraction tool (BET), brain surface extraction (BSE), watershed algorithm (WAT), hybrid watershed algorithm (HWAT), graphcuts (GCUT) and robust brain extraction (ROBEX). The experiment showed the proposed method was precise and robust.
2014 Vol. 33 (5): 525-531 [Abstract] ( 276 ) HTML (1 KB)  PDF (1074 KB)  ( 533 )
532 A 3D MATMI Reconstruction Algorithm Based on  Characteristics of Acoustic Transducer#br#
MA Ren   ZHANG Shun Qi  YIN Tao   LIU Zhi Peng#*
DOI: 10.3969/j.issn.0258-8021.2014.05.03
Aim to apply MATMI reconstruction algorithm to general sound detection systems, the influence of acoustic transducers on MATMI image reconstruction were investigated in this paper. The acoustic intensity measurement system was used to measure the acoustic field, and then the data was used to build the acoustic transducer model by a interpolation method. The model was applied to forward and inverse problems of MATMI based on Green’s function and discretization method. In order to verify the algorithm, a simulation was carried out using sphere scan schema and cylinder scan schema. A 3D phantom model was set up based on SL model in CT, with the help of finite element analysis method and the distribution of the transient electromagnetic field and the eddy current were calculated. Simulation and reconstruction results through numerical calculation using Matlab were obtained. Results show that the algorithm can reconstruct the distribution of acoustic source vector; the correlation coefficients are 9849% and 9496%, which can be applied to the general transducer. This study provided a basis for the experimental study of MATMI and a precise reconstruction of conductivity distribution.
2014 Vol. 33 (5): 532-538 [Abstract] ( 225 ) HTML (1 KB)  PDF (2232 KB)  ( 440 )
539 Detection and Assessment of Body Balance Function Based on Static Posturography
HAN Jun  LUO Zhi Zeng*ZHANG Qi Zhong
DOI: 10.3969/j.issn.0258-8021.2014.05.04
In this paper, a new method is proposed aiming to effectively detect and assess the balance dysfunction of elderly and hemiplegic patients. First, five indicators were selected under conditions of eye open or eye closed for quantitative detection of the balance function, including track length of center of gravity, track length per unit area, kurtosis, distribution ratio of center of gravity between left and right, distribution ratio of center of gravity between front and rear. Then the indicators were fused together using principal component analysis (PCA). Next, weights of principal component factors were determined by their variance contribution rate. Finally, the balance function assessment of subjects was completed by computing a comprehensive evaluation based on PCA. Thirty subjects with balance dysfunction (case group) and thirty sex-, age-, height and weightmatched healthy subjects (control group) were recruited in the experiment. Their balance function were detected and assessed twice within two weeks using an independently research system. The statistical value of comprehensive evaluation index is 4.067±0.540
(n=30,mean±SD) in the control group, while it is 2.054±0.685 (n=30,mean±SD) in the case group. Results show that the method for balance function detection and assessment is reasonable and practical.
2014 Vol. 33 (5): 539-545 [Abstract] ( 615 ) HTML (1 KB)  PDF (1280 KB)  ( 773 )
546 Assessment of Facial Growth for Children Based on ThreeDimensional Face Database
LIN Sheng Liang   JI Chai   XU Lin   ZHAO Zheng Yan*
DOI: 10.3969/j.issn.0258-8021.2014.05.05
It is acepted that people with inherited diseases,  such as WS and DS, have features of facial abnormalities. This work was undertaken to establish 3D face database from birth to 18 years old and the facial growth norms of children of the Chinese Han population using 3D stereophotogrammetric devices. In this study, 5600 neutral expression subjects were collected including 2803 males and 2797 females. To build 3D face database,  original 3D data were preprocessed, and the input faces were required to be well aligned to a reference face. In the first step, the face region was separated from 3D data based on the theory of the largest connectivity. Secondly, the coarse alignment was achieved by approximating a 3D affine transformation between the input face and the reference face. At last, the ICP algorithm was used to align the face more precisely. The database was applied to access the children facial growth by measuring 18 craniofacial indices of 55 DS faces and 30 WS faces, which came from Zhejiang province. Results show that the distribution of 763% intercanthal breadth is above the 90th percentile, the distribution of 618% nose length is under the 10th percentile, the distribution of 872% ear length is under the 10th percentile,and the distribution of 89% upper face depth is under the 10th percentile. The CVI is 1630～2117 in DS. For WS, the distribution of 50% nose breadth is above the 75th percentile, the distribution of 667% mouth breadth is above the 75th percentile, the distribution of 633% bitragal breadth is under the 25th percentile and CVI is 1714～2365. These results illustrate that the assessment system can reflect the feature of the special face, therefore the 3D face database provides a dependable 3D facial data for the research of children face. The research of facial growth assessment using the method of anthropometry has a wide range of applications, including children growth, evaluation of the abnormal face.
2014 Vol. 33 (5): 546-555 [Abstract] ( 281 ) HTML (1 KB)  PDF (1558 KB)  ( 433 )
556 Brain Functional Network of Depression during  Facial Emotional Processing#br#
GAO Yun  CAO Dan  LI Ying Jie #*
DOI: 10.3969/j.issn.0258-8021.2014.05.06
The present study investigated whether functional brain networks are abnormally organized in the depression under the emotional stimuli. We applied phase synchronization to construct the connectivity and global and local efficiency to explore the smallworld topology of the brain networks. Sixteen depressed patients and fourteen healthy subjects participated in the study, with the continuous scalp electroencephalography (EEG) collected. We constructed the phase synchronization matrices using the EEG in low gamma (30～50 Hz) and high gamma (50～80 Hz) bands. We found the global phase synchronization values of depressed group are significantly higher than healthy controls. When costs were between 025 and 050 in low gamma band and between 025 and 055 in high gamma band, global and local efficiency of brain networks were between random graph and lattice, indicating the smallworld networks. When costefficiency reached maximum (cost equaled to 03) in high gamma band, global efficiency had significant differences between groups, without findings on local efficiency. When cost equaled to 05, abnormal activities were found in the left temporalparietal and occipital region. Results reflected the abnormal network features in depression under emotional processing by the measures of global and local efficiency and provided a reference for researches on neural networks in depression.
2014 Vol. 33 (5): 556-563 [Abstract] ( 384 ) HTML (1 KB)  PDF (1765 KB)  ( 511 )
564 A Diagnosis Model for Amnestic Mild Cognitive Impairment Based on Structural Network Characteristics of the Brain#br#
YUN Rui Juan1   WU Shui Cai1*LIN Chung Chin2,3HUANG Chu Chung4   LIN Ching Po4WANG Pei Ning5   CHAO Y
DOI: 10.3969/j.issn.0258.8021-2014.05.07
The aim of this work is to select topological characteristics of structural network which were higher correlated with cognitive performance and estimate the classification models to classify normal aging and amenstic mild cognitive impairment (aMCI) patients. In two groups of diffusion tensor image (DTI) dataset, a group has 52 normal aging subjects and another group has 39 aMCI patients. We employed the diffusion tensor image to construct the structural network in each group and used the method of graph theory to extract the characteristics of structural network. We selected significant features by the correlation analysis between the characteristics of brain network and subject’s
minimental state examination (MMSE) score. These features were used to establish five kinds of classification model for evaluating the classification efficiency of the models. For normal aging dataset and aMCI dataset, 18 characteristics of the structural network were selected as features, which are significantly associated with cognitive ability and locate in 9 brain areas according to the automated anatomical labeling (AAL) template in each group. However, the features and the related regions are different for the two datasets. Among 5 algorithms, sequential minimal optimization learning algorithm for support vector machine regression model was more accurate due to the higher specificity of 8846%, the higher sensitivity of 8305% and the higher accuracy of 8571%. Brain structural network metrics which were correlated greatly with the cognitive performance could be taken as biological marker pointers to establish the classification model to classify normal aging subjects and aMCI patients. Furthermore, these structural network features can provide the information of connection changes between corresponding brain regions.
2014 Vol. 33 (5): 564-573 [Abstract] ( 281 ) HTML (1 KB)  PDF (2196 KB)  ( 483 )
574 Effects of the Extracellular Electrical Stimulation on the Excitability of Optic Nerve Fibers by Mathematical Modeling
GUO Hong1  SUI Xiao Hong1   LI Meng Hui2   LI Li Ming1*
DOI: 10.3969/j.issn.0258-8021.2014.05.08
A visual prosthesis based on penetrating electrode stimulation within the optic nerve (ON) is a potential way to restore partial functional vision for the blind patients. In order to provide theoretical basis for electrical stimulation strategies and the electrode design of abovementioned visual prosthesis, a finiteelement model of the electric field generated by an actual penetrating microelectrode was constructed in COMSOL, and then coupled to the multicompartment cable model of the optic nerve fiber implemented using NEURON. With this method, we evaluated the effects of stimulating electrode location, pulse duration of electrical stimulus and electrode structure on the excitation thresholds of optic nerve fibers. Simulation results showed that the impact of the former two factors on the fiber thresholds agreed with that reported in previous animal and simulation studies, which demonstrated the effectiveness of our models. The following suggestions about the design of stimulus pulse duration and electrode structure of the penetrative ON prosthesis were also obtained according to our simulation work. Stimulus with narrow pulse width helps reduce energy consumption. The electrode taper should be designed as small as possible to lower the threshold but should not disturb the electrode insertion. Decreasing the electrode exposed area helps lower the current threshold and therefore reduces the power consumption, but it also increases the charge density threshold, which eases to result in electrochemical damage to ON. Thus, the electrode exposed area should be designed appropriately to avoid excessive power consumption and tissue damage. Changing the coating thickness of the electrode has no significant effect on the fiber threshold, but a electrode with thin coating is recommended to decrease the insertion difficulty. These results are also of valuable reference to the electrical stimulation of other nerve fibers of human body.
2014 Vol. 33 (5): 574-584 [Abstract] ( 304 ) HTML (1 KB)  PDF (3974 KB)  ( 388 )
585 Preclinical Study of Anticoagulation Regimens in Animals after Implantation of CHVAD
XU Chuang Ye1,2LIU Xiu Jian1,2WU Guang Hui1,2HOU Xiao Tong1  LI Hai Yang1YANG Peng3   LIN Chang Yan1,2#*
DOI: 10.3969/j.issn.0258-8021.2014.05.09
Sheep models are often used to verify the blood compatibility, biological safety and reliability of VADs as well as the impact on physiological conditions of animals. Effective and safe anticoagulation regimens are strongly needed to reduce risks of thrombosis and bleeding. This study is to evaluate the effect of anticoagulation for animals after implantation of CHVAD with heparin and warfarin, aiming to offer anticoagulation data for longterm survival experiments and clinical applications. CHVAD models were established in six healthy sheep by constructing blood bypass of left ventricular →VAD →descending aorta. Heparin of 250 U/kg was injected through jugular vein during operation. Continuous heparin infusion was used in the prior four days after implantation to keep ACT and aPTT values as 15 to 20 times as the baseline. From the third day, proper dosage of warfarin was used orally to make INR in the target range of 12～20. Bleeding complications were closely monitored through the experiment. At the termination point, we examined whether there was thrombosis in the blood pump, grafts and anastomotic stoma. Macroscopical examinations were performed in major organs to check congestion and infarction. Tissues of the organs were collected to make HE staining to evaluate histopathological changes. Bleeding complications were not found in all animals throughout the experiments. Intraoperative ACT values were (326 ± 33) s. ACT values were（157±28）s in the prior four days, reaching the target range. The aPTT increased slowly and reached the lower limit of the target range at the fourth day. No thrombosis and fibrosis tissue were found in blood flow channel except for Sheep4. Pathological images showed no thrombosis, necrosis and microembolus in endstage organs under the anticoagulation regimen. Under the anticoagulation regimen of continuous intravenous heparin maintaining ACT 15～20 times the baseline and  later oral warfarin maintaining INR values within the range of 12～20, thrombosis and bleeding complications could be well controlled in sheep models for CHVAD, providing reference for later animal experiments.
2014 Vol. 33 (5): 585-592 [Abstract] ( 287 ) HTML (1 KB)  PDF (2831 KB)  ( 443 )
593 Fabrication and Evaluation of Polyurethane Scaffolds with HoneycombLike Structure
XU Wei Jun  QIAN Jun Min*  JIN Xin Xia
DOI: 10.3969/j.issn.0258-8021.2014.05.010
In this study, poly (εcaprolactone) diol was synthesized via ringopening polymerization of εcaprolactone using 2,2′dithiodiethanol as an initiator, and then polyurethane was synthesized through addition polymerization of poly (εcaprolactone) and hexamethylene diisocyanate. Polyurethane was characterized by FTIR, XRD and DSC. Polyurethane scaffolds were fabricated by biotemplating technique, and their porous structure, porosity and mechanical properties were characterized by SEM, archimedes principle based method and mechanical test, respectively. MC3T3E1 cells were cultured on polyurethane scaffolds to evaluate their cytocompatibility. The results indicated that polyurethane scaffolds had a honeycomblike channels with a diameter range of 100 μm to 140 μm, and their porosity and compressive modulus were 772%±41% and 29902 kPa, respectively. Immunofluorescence staining and live/dead staining results indicated that MC3T3E1 cells could adhere and proliferate on the scaffolds. The results suggested that the honeycomblike polyurethane scaffolds were a promising candidate for bone tissue engineering.
2014 Vol. 33 (5): 593-599 [Abstract] ( 330 ) HTML (1 KB)  PDF (2472 KB)  ( 368 )
600 Preparation and Characterization of C6Oxidated Bacterial Cellulose/Chitosan Composite
LIAO ShiBo1,2HUANG Shu Yu2   LAI Chen1   XI TingFei1#*WU Min2LIU Yu Ping2  YAN Yi Min2 
DOI: 10.3969/j.issn.0258-8021.2014.05.011
Bacterial cellulose (BC) is a natural scaffold for bone tissue engineering. To improve its degradability and microstructural controllability, C6oxidated bacterial cellulose/chitosan (OBC/CH) composite scaffolds were prepared by lyophilization of a mixture of OBC suspension and CH solution in a cylindrical mold. The original BC was subjected to 2,2,6,6tetramethylpyperidine1oxyl radical (TEMPO)/NaBr/NaClOmediated oxidation to introduce surface carboxyl groups before mixing. The integration of CH within OBC was performed by 1ethyl3(3dimethylaminopropyl) carbodiimide/Nhydroxysuccinimide (EDC/NHS)mediated crosslinking. The products were characterized by FTIR, solidstate 13CNMR, XRD, in vitro degradation, porosity and FESEM. The FTIR and 13CNMR results show that OBC and CH were crosslinked successfully; XRD result shows that the crystallinity of the products was slightly decreased with the increase of CH content, the difference was less than 31%; the degradability of OBC and OBCCH in vitro was increased significantly, and the degradation rate within 8 weeks was 402% when ((OBCCOOH)/(CHNH2))/(n/n)＝1/45; FESEM and porosity results show that the pore size and porosity of OBCCH scaffolds were greater than that of BC and OBC scaffolds, and the maximum porosity was reached 97% when ((OBCCOOH)/(CH0NH2))/(n/n)＝1/45. In conclusion, OBCCH is an ideal scaffold for bone tissue engineering, with good degradability and microstructural controllability.
2014 Vol. 33 (5): 600-608 [Abstract] ( 294 ) HTML (1 KB)  PDF (2835 KB)  ( 513 )
609 Recent Advances in Bioinspired Olfaction/Gustation Sensors and their Applications#br#
QIN Zhen1   DONG Qi   HU Liang   HUANG LiQuan 2  HSIA Jimmy3   WANG Ping1#*
DOI: 10.3969/j.issn.0258-8021.2014.05.012
The biological chemical sensory system has the ability to discriminate and identify thousands of chemical compounds at very low concentrations with extremely higher sensitivity and specificity than current artificial sensing devices. Recently, many researchers are trying to develop novel chemical detecting systems called as bioinspired olfaction/gustation sensors which take advantages of optimized natural molecular recognition. Bioinspired olfaction/gustation sensors consist of a primary transducer and a secondary transducer. The primary transducer is the biological recognition element of molecules such as biological tissues, cells and proteins. The second ary transducers such as optical devices, electrochemistry devices and acousticwave devices are the biochips for the detection of binding of chemical compounds to the primary transducers. In this article, we introduced the mechanism of biological sense of smell and taste, and outlined the latest advances of bioinspired olfaction/gustation sensors.  Current research trends and future challenges in this field will be discussed.
〖KH2D〗
〖WTHZ〗Key words：〖WTBZ〗〖BP(〗┣┣（英）关键词┫┫〖BP)〗
2014 Vol. 33 (5): 609-619 [Abstract] ( 382 ) HTML (1 KB)  PDF (3067 KB)  ( 1011 )
620 Research Advances in the Tumor Ablation Induced by Nanosecond Pulse
REN Zhi Gang    CHEN Xin Hua   ZHOU Lin   ZHENG ShuSen*
DOI: 10.3969/j.issn.0258-8021.2014.05.013
Cancer remains a leading cause of human death worldwide and the total number of cases globally is increasing constantly, thus it is urgent to explore new and effective therapies for the cancer treatment. This paper reviewed 10 primary biological hallmarks of the cancer, introduced the distinguished advantages of tumor ablation induced by nanosecond pulse targeting tumor biological hallmarks, such as inducing cell apoptosis, inhibiting angiogenesis, destroying tumor microenvironment. We also elaborated the research progress of tumor ablation induced by nanosecond pulse employed in the treatment of cutaneous melanoma, basal cell carcinoma, squamous cell carcinoma, hepatocellular carcinoma and other tumors, showing an attractive application prospect.
2014 Vol. 33 (5): 620-624 [Abstract] ( 568 ) HTML (1 KB)  PDF (1437 KB)  ( 799 )
625 Study on Ventilator Weaning for Pediatric Patients Based on Fuzzy C Means Clustering Algorithm
YU Gang1   ZHENG Kun1*YE Sheng2
DOI: 10.3969/j.issn.0258-8021.2014.05.014
2014 Vol. 33 (5): 625-629 [Abstract] ( 181 ) HTML (1 KB)  PDF (1809 KB)  ( 509 )
630 Structure Design and Implementation on a LightWeight Exoskeleton Training Device for Hand Rehabilitation
YI JinHua1   LI Ji Cai1   HU Xin1   YU Hong Liu1*
DOI: 10.3969/j.issn.0258-8021.2014.05.015
2014 Vol. 33 (5): 630-634 [Abstract] ( 241 ) HTML (1 KB)  PDF (1901 KB)  ( 558 )
635 Medical Evaluation and Application of a Fast Automatic Airway Tree Segmentation Algorithm#br#
QI ShouLiang1〓LI ZhengHua1〓YUE Yong2〓XU MingJie1〓HAN JW van Triest1〓KANG Yan1#*
DOI: 10.3969/j.issn.0258-8021.2014.05.016
2014 Vol. 33 (5): 635-640 [Abstract] ( 216 ) HTML (1 KB)  PDF (2254 KB)  ( 487 )
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