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2014 Vol. 33, No. 6 Published: 2014-12-20 641 Brain Computer Interface: Translation from Miracle to Reality YAO De Zhong#* DOI: 10.69/j.issn.0258-8021.2014.06.01 Braincomputer interface (BCI) is the technique which uses online brainsignal processing to enhance the interactions between human and environments. This article summarizes the main aspects of BCI, and the challenges for BCI from miracle to reality    2014 Vol. 33 (6): 641-643 [Abstract] ( 543 ) HTML (1 KB)  PDF (489 KB)  ( 1102 ) 644 Key Techniques in Motor Imagery Based BrainComputer Interface LIU Tie Jun＃ ZHANG Rui XU Peng＃* DOI: 10.3969/j.issn.0258-8021.2014.06.02 Motor imagery based braincomputer interface (MI BCI) has been considered as the most promising BCI in practical application. However, several urgent problems need to be solved for MI BCI. Based on our research experience in past several years, this paper discusses the developed methods in our group for signal acquisition, feature extraction, pattern recognition and online BCI system. As for the acquisition aspect, we designed an amplifier that can remove the DC offset effectively. Several improved algorithms based on common spatial pattern (CSP) are developed to increase the immunity to noises. As for pattern recognition, several variants of linear discriminative analysis are developed to improve the recognition rates. Based on those methods, we built a hybrid online BCI system that combined motor imagery and motion onset visual evoked potential (MOVEP). 2014 Vol. 33 (6): 644-651 [Abstract] ( 766 ) HTML (1 KB)  PDF (1061 KB)  ( 1491 ) 652 The CrossBrain Neurofeedback Platform with High Ecological Validity#br# LIU Wei Jie1 DUAN Lian1 DAI Rui Na1 XIAO Xiang1 LI Zheng1 DOI: 10.3969/j.issn.0258-8021.2014.06.03 In this work we proposed a novel concept of crossbrain neurofeedback, extending neurofeedback research from regulation of neural activities of a single brain to that of neural synchronization of two interacting brains. This article describes the design and implementation of two sets of functional nearinfrared spectroscopy (fNIRS) based twoperson neurofeedback platforms with high ecological validity: 1) platform based on a single fNIRS recording system at one location and 2) an internetbased platform connecting two fNIRS recording systems at different locations. Each platform simultaneously records two participants’ neural signals, calculates the neural synchronization index in realtime, and feeds back the index to the participants through a visualization. The feedback information enables participants to try different regulation strategies to voluntarily control their neural synchronization, which may lead to changes in social cognition and behavior. In an application of single fNIRS based platform, HbO signals in the specific brain regions of two subjects were so much alike, indicating that their neuro activities were synchronized. Moreover, in preliminary experiment for the internetbased platform, two subjects performed collaboration task. The ball in the most of the time is maintained between two dotted lines, which implied two subjects were in synchronization. Preliminary experiments demonstrating that both participants successfully regulated and synchronized their brain activities in a social interaction situation validate our fNIRSbased crossbrain neurofeedback platform.  2014 Vol. 33 (6): 652-658 [Abstract] ( 481 ) HTML (1 KB)  PDF (1975 KB)  ( 754 ) 659 A Review on Invasive Brain Machine Interface CAO Yan1,2 ZHENG XiaoXiang1,2,3#* DOI: 10.3969/j.issn.0258-8021.2014.06.04 The brain machine interface establishes a new communication and control pathway between the brain and external devices. It provides a new approach to understand more about the structure and function of brain. On the other hand, it is a possible treatment to restore the movement functions for patients. Invasive brain machine interface can realize elaborate motion control with the high spatial and temporal resolution of tremendous information embedded in the neural firings. Therefore it emerges as an interdisciplinary research area and attracts more attention. The paper reviews the development of invasive brain machine interface, especially on neural acquisition, movement decoding and artificial sensory feedback. 2014 Vol. 33 (6): 659-665 [Abstract] ( 537 ) HTML (1 KB)  PDF (814 KB)  ( 1084 ) 666 Motor Imagery Signal Classification Based on HDP AR HMM WU Jun1 YANG Ya2 YU ZhuLiang1#* GU Zheng Hui1 LI YuanQing1# DOI: 10.3969/j.issn.0258-8021.2014.06.05 Hidden Markov model (HMM) is well applied in brain computer interface, especially in the classification of motor imagery(MI) electroencephalogram (EEG) signal. Conventional methods  use HMM to model EEG signal, then use the observed signal under controlled state to estimate the HMM parameters and finally classify the EEG signal through the trained HMMs. However, due to the characteristics of low signaltonoise ratio(SNR), high dimensionality and complexity of motor imagery EEG signal, HMM cannot fully describe the dynamic property of motor imagery EEG signal. In this paper, we use hierarchical Dirichlet process (HDP) with selfclustering ability to describe MI signals and then use AR/VAR model to highlight the time property of MI signal. Finally we combine them with Markov switching processing (MSP) so that we can get more information of MI signal. In order to verify this method, we tested the algorithm on our inhouse data and some of the 2003 BCI international competition data sets. High accuracy on classification of MI is obtained. 2014 Vol. 33 (6): 666-672 [Abstract] ( 390 ) HTML (1 KB)  PDF (2214 KB)  ( 565 ) 673 Neural Substrates of  Music Investigated by EEG and fMRI YAO De Zhong#* WU Dan LAI Yong Xiu GONG Dian Kun LUO Cheng LU Jing MA Wei Yi YANG Hua XU Peng DOI: 10.3969/j.issn.0258-8021.2014.06.06 Music is a special crosscultural artistic style that appeared and evolved along with the development of the human being. The exploration of the mystery in music and the relation between music and brain is a way to understand humanity itself, thus it is a very charming area for science and society. In this paper, based on our experiences, examples are presented on studies of music note attribute cognition, brain network of musician and brain wave music. We hope that these primary results are helpful for the readers in their future efforts. 2014 Vol. 33 (6): 673-676 [Abstract] ( 503 ) HTML (1 KB)  PDF (780 KB)  ( 575 ) 677 Multiintensity Edge Detection for Colony Images Based on the Function of Photoreceptor in Visual System #br# LUO Jia Jun WU Wei* FAN Ying Le GAO Yun Yuan DOI: 10.3969/j.issn.0258-8021.2014.06.07 Considering the superiority of visual nervous system in contour perception, a new method of image edge detection based on the function of photoreceptor in visual system was proposed in this paper. Firstly, the neural network was constructed with leaky integrateandfire (LIF) neuronal electrophysiological model. Secondly, each neuron would be classified as excitation (ON) type or inhibition (OFF) type according to the neural firing pattern. And then the weak edges were highlighted by using centersurround antagonistic receptive field feature and feedback enhancing mode of neuronal excitation. Meanwhile the image movement in multidirection and multiscale was applied to overcome the adaptability of photoreceptor and highlight the contrast of weak details. Finally the edge image was acquired by fusing the variance information, such as photosensitive neural network’s firing rates. In this paper, twenty colony images having rich details in the edge were selected as experimental samples. The results of multiintensity edge detection were assessed by the confidence of edge and reconstruction similarity. It was proved that the new method can effectively detect the intact multiintensity edge image, especially the means of reconstruction similarity in the weak edge detection is improved significantly, which is higher than 08 (P<005). The method of edge detection discussed in this paper provides a brandnew idea for multiintensity edge details image processing based on the feature of physiological visual. 2014 Vol. 33 (6): 677-686 [Abstract] ( 312 ) HTML (1 KB)  PDF (2179 KB)  ( 375 ) 687 Automatic Analysis Method of Macular Edema Classification for Diabetic Retinopathy Images#br# ZHENG Shao Hua* CHEN Jian PAN Lin YU Lun DOI: 10.3969/j.issn.0258-8021.2014.06.08 Diabetic macular edema (DME) can appear in any stage of the diabetic retinopathy (DR) and is the leading cause of vision impairment in people with diabetes. Therefore, the automatic analysis of DME plays a key role in the DR screening program. According to the DME international clinical classification standard, detecting and judging the presence of hard exudates (HEs) close or relate to macula fovea (MF) is a standard method to assess DME in the fundus images. A synthetic improvement method based on existing mathematical morphology technique is selected for HEs detection. A novel method of macular fovea center location is proposed based on the directional local contrast filter and the local vessel density. Then the optic disk region can be easily located and removed for reducing the impact to the HEs detection. Only the large vessel segmentations were used for the vessel density calculation. From the testing results on the 169 images from HEIMED public dataset, the sensitivity and specificity of HEs detection on image level are 100% and 922%, respectively. The accuracy of macular fovea center location reaches 982%. And the accuracy for each DME classification is more than 88%. The proposed method would have important clinical application potentials. 2014 Vol. 33 (6): 687-695 [Abstract] ( 453 ) HTML (1 KB)  PDF (2389 KB)  ( 577 ) 696 Corticomuscular Synchronization Analysis Based on Granger Causality during Walking#br# NIU Xiao Chen1  CHEN Xiao Ling1  CHEN Ying Ya1  WU Xiao Guang1  DU Yi Hao2  XIE Ping1* DOI: 10.3969/j.issn.0258-8021.2014.06.09 The aim of this study is to investigate functional relationship between brain cortex and muscles during walking and explore the differences of the functional relationships between forward and backward walking. This article collects the EEG and EMG datasets which acquired simultaneously from 10 healthy subjects during forward and backward walking. Granger causality (GC) method, which can reveal the coupling connection and information flow direction among two signals, was applied to analyze the EEG and surface EMG data. Further, the EEGEMG significant  GC area was defined to quantitatively describe the corticomuscular function coupling and information flow direction of different muscles at different frequencies. Then the EEG spectral power was calculated to analyze the relationship with corticomuscular function coupling. The results of Wilcoxon test show that during backward walking, the EEG→EMG and EMG→EEG significant GC area indexes of rectus femoris and tibialis anterior muscle were lower compared with forward walking(α=005, P<005), and a linear relationship exists between EEG spectral power peak and GC peak at EEG→EMG based on linear regression analysis(α=005, P<005). These illustrate that there exists directed coupling between EEG and EMG during walking, and alpha and beta rhythm involve the control and feedback process of walking. It verifies that the proposed methods can further describe the synchronization feature and functional connection between cortex and muscles. 2014 Vol. 33 (6): 696-706 [Abstract] ( 304 ) HTML (1 KB)  PDF (3860 KB)  ( 606 ) 707 Sample Entropy Evaluation of EEG complexity Based on Low Frequency Photon Stimulation in Light Sleep ZHOU Hui  TAO Ling*  QIAN Zhi Yu  ZHAO Cui Hua DOI: 10.3969/j.issn.0258-8021.2014.06.010 Patients with sleep disorders have difficulties entering deep sleep from light sleep. It is important to research the changes of EEG during the light sleep for sleep efficiency and quality. In this paper, the EEG response during the light sleep under photon stimulation was studied by analyzing the EEG complexity changes, and the impact of photon stimulation on sleep EEG was studied as well. Ten volunteers’ EEG data during photon stimulation and normal sleep were gained by Neuroscan. Firstly, the EEG data of light sleep were obtained by using timefrequency analysis. Secondly, the theta waves, delta waves, alpha waves and the spindles were extracted from the EEG by using wavelet packet decomposition. Thirdly, the complexity of EEG and its components with different frequencies during the light sleep were calculated by using sample entropy. Lastly, the light sleep EEG complexity between normal sleep and photon stimulation（5 Hz）sleep was compared to research the impact of photon stimulation. We found the average value of EEG complexity under photon stimulation is 0514 15，significantly less than the average value of normal sleep, 0589 23, especially in central and parietal region（P<005）. The conclusion is that photon stimulation（5Hz）can induce the synchronous response of EEG, and strengthen the EEG rhythm, which helps the brain enter deep sleep. 2014 Vol. 33 (6): 707-714 [Abstract] ( 383 ) HTML (1 KB)  PDF (2322 KB)  ( 851 ) 715 A Human Body Modeling for Risk Factors of Chronic Disease with an  Artificial Neural Network BAO Jia Ming1   WANG Shun2   ZHU Chao Yang2  WANG Yi Qing1  XU Ya Shi1  WANG Qiang2 DOI: 10.3969/j.issn.0258-8021.2014.06.011 The aim of this study is to set up an individualized modeling method, based on the back propagation (BP) learning algorithm on an artificial neural network (ANN), for a risk factor control of chronic disease. The inputs of the model include the parameters about physical activity, food intake (salt, grains, vegetables, fruits, meat and poultry, eggs, fish, legumes, milk, oil, animal internal organs), drinking and smoking. And the outputs are systolic pressure, diastolic pressure, glucose, heart rate and BMI. The reliability of the model was test by residual analysis. The result showed that coincidence rates of measured outputs with the estimated ones of 9 models were over 80% among 13 volunteers. So it is concluded that the proposed method is generally practical, providing a basis for the design of individualized state control of chronic disease risk factor. 2014 Vol. 33 (6): 715-721 [Abstract] ( 297 ) HTML (1 KB)  PDF (1686 KB)  ( 414 ) 722 Depthcontrolled and Automated Piezoelectric Micro issection System ZHU Jun Hui1  WANG Yong1  ZHU Meng1  CHEN Rui Hua2*  RU Chang Hai1* DOI: 10.969/j.issn.0258-021.2014.6.12 In order to obtain a specific population of cells or a single cell from different tissue slice for the research, a depthcontrolled and automated piezoelectric microdissection system was developed to solve problems of time consuming, easy fatigue, and low accuracy in the manualdissection. On the basis of different gray values of foreground and background to detect and track the tip of the dissection needle〖DK〗’s position in rea ltime, and according to the change of the X axis to judge whether the dissection needle contact the target surface, the depth information was acquired. By analyzing the dissection experiments conducted in different conditions, it is shown that this proposed system can place the needle in any positions of the tissues, quickly scan the whole samples to determine the target area and realize the dissection in specify position with arbitrary shape of biological samples. The fineness of cutting line is 15 μm, the resolution of cutting is 50 nm，and cutting error is 05 μm, reaching the unicellular cut level. In addition, the separation of target tissue sections can be realized automatically. The method provides the improvement of the precision and efficiency of dissections, showing its superiority. 2014 Vol. 33 (6): 722-728 [Abstract] ( 367 ) HTML (1 KB)  PDF (2783 KB)  ( 370 ) 729 Biomechanical Effect of an Interspinous Process Spacer for L4/5 of Lower Lumbar: a Finite Element Analysis#br# CAI Fang Zhou1,2  GU Xue Lian1*  HAN Shou Peng2  SONG Cheng Li1  Chen Bo3 DOI: 10.3969/j.issn.0258-8021.2014.06.013 To analyze the effect of the stability of an implanted homologous XSTOP device in the injury segment L4/5 and the biomechanical behavior of adjacent segments. A CTscanner was used to acquire normal lumbar images. With the help of Mimics14, Geomagic Studio2012, Hypermesh12 and Abaqus612-1, the finite element (FE) model (the lower lumbar L2～L5 segments) with or without interspinous spacer XSTOP was constructed. Upon validation, a finite element model of L2～L5 was developed to simulate and analyze the biomechanics of the intact and XSTOP dynamic fixation states by simulating flexion, extension, lateral bending and axial rotation. The comparison of degree of freedom (DOF) and intradiscal pressure of two set models predicted that the levels adjacent to the implanted level were not significantly affected by the implanted XSTOP. There was a distinct restriction in the range of extension and intradiscal pressure at the implanted segment, and DOF decrease to 7483%. Furthermore, the largest von Mises stress showed on the interface between the spinous process and the implant at the position of extension. Respectively, the largest stress value is 333 MPa and 1356 MPa. In conclusion, the XSTOP can effectively restrict the DOF of extension and unloading disc pressure, without affect adjacent segment. Moreover, this study also provides theoretical and biomechanical analysis to support the clinical performance of the XSTOP and its further improvement of the device design. 2014 Vol. 33 (6): 729-736 [Abstract] ( 274 ) HTML (1 KB)  PDF (4275 KB)  ( 613 ) 737 Research on a Novel Sodium AlginateDexamethasone Composite Coating with MultiAldehyde Groups Applied to Extracoporeal Circuits#br# GAO Wen Qing1  LI Tong1*  YU Mei Li2  HU Xiao Min1  DUAN Da Wei1 DOI: 10.3969/j.issn.0258-8021.2014.06.014 The aim of this work is to prepare a novel composite coating of sodium alginate and dexamethasone. By optimizing the coating mode and conditions,  the properties of stability, anticoagulation and controlled release were evaluated. Polyethyleneimine (PEI) was coated on PVC pipelines surface pretreated with acidification, dexamethasone sodium phosphate (DSP) was coated on PEIcoated pipelines (PP) with ionic bond, DSP coated pipelines were created (Group PPD). Pipelines coated OSADXM composite were created by ionic bond (Group PPI) or covalent bond (Group PPC). The control group (Group C) was set as well. The optimum coating condition was obtained by the orthogonal test. By evaluating the properties of different coated pipelines including anticoagulation, platelet adhesion, protein adhesion and release in vitro, the optimum coating mode was determined. DSP can be bound to PVC surface in Group PPD, PPI and PPC. The optimum immobilization quantity of DSP on different groups are (333±075)，(163±076)，(206±068) μg/cm2. The platelet adhesion (109/L) of Group PPI and PPC (1388±189 and 1913±340) was significantly reduced than that of Group C (4138±320). The protein adhesion (mg/cm2) of  Group PPI and PPC (HAS: 2986±1357 and 4667±320, HPF: 3499±352 and 4567±379) was significantly decreased than that of Group PPD (Has: 6873±426, HPF: 7254±790). The release property of Group PPC is superior to that of Group PPI. The coating of OSADXM composite exhibited improved hemocompatibility. Covalently bound DSP can be controlled released.  2014 Vol. 33 (6): 737-745 [Abstract] ( 390 ) HTML (1 KB)  PDF (2275 KB)  ( 490 ) 746 Biodegradation of Electrospun Poly (Llactic acidcoεcaprolactone)/Collagen Composite Vascular Grafts WANG Tao1  CHEN Jian Feng2  ZHAO Jun1*  WU Tong2  MO Xiu Mei2  MEI Jia Cai1 DOI: 10.3969/j.issn.0258-8021.2014.06.015 To evaluate the biodegradation and biocompatibility of poly (Llactic acidcoεcaprolactone) (P(LLACL))/collagen graft, P (LLACL) collagen graft scaffolds were made through electrospinning. The prepared scaffolds were set as experimental group (n=40) and the commercial artificial vessel made of ePTFE was set as control group (n=40). The scaffold samples were implanted in the left dorsal muscle of rabbits, while ePTFE graft materials were implanted in the opposite side. On day 10, 30, 90 and 180 after the implantation, the samples were harvested. The histological staining was applied to observe the degradation of the material and tissue reaction. The number of neutrophils, macrophages and lymphocytes were counted at the high magnification (400×) using the optical microscope. Under the microscope, slight tissue reaction was revealed in the area of P (LLACL)/collagen material. On day 90, the material broken was observed. Some connective fibrous tissue was revealed in the material, a capsulelike membrane was established over the area. During the process of degradation, most of the materials were absorbed within 180 days. The structure and distribution of the tissue cells was highly similar to that of the surrounding area, indicating that the remodeling of the embedded tissue was almost finished. The ePTFE materials were revealed still maintaining the structure encompassed in a thin layer of fibrous connective tissue. The result of cell count showed that the type and trend of cell reaction had no difference after the different stages of postoperation. However, the count of neutrophile granulocyte in experimental group was more than that in the control group on day 10 (2244±372 vs 1922±181 /025 mm2, P<005), while no difference of various types of cells was observed between the two groups post operation. The degeneration of P (LLACL)/collagen material was 90-180 days, which is a satisfying biological performance in the degradation and biocompatibility. 2014 Vol. 33 (6): 746-752 [Abstract] ( 525 ) HTML (1 KB)  PDF (1920 KB)  ( 447 ) 753 Motor Imagery EEG Analysis of the Spinocerebellar Ataxia Patients ZHANG Ting1  WANG Yong Xuan2  LIU Rong 1* DOI: 10.3969/j.issn.0258-8021.2014.06.016 2014 Vol. 33 (6): 753-758 [Abstract] ( 470 ) HTML (1 KB)  PDF (2045 KB)  ( 527 ) 758 The Behavior Analysis of the Upper Limb Based on Laparoscopic Training YE Sha Sha  WANG Shu Yi*  BI Dong Dong DOI: 10.3969/j.issn.0258-8021.2014.06.017 2014 Vol. 33 (6): 758-763 [Abstract] ( 256 ) HTML (1 KB)  PDF (1909 KB)  ( 400 ) 764 Investigation and Evaluation on Method of Transparency Measurement of Tissue Engineered Cornea TAO Meng1  LI Wen Kang1  LI Gang2  LI Hong1* DOI: 10.3969/j.issn.0258-8021.2014.06.018 2014 Vol. 33 (6): 764-768 [Abstract] ( 427 ) HTML (1 KB)  PDF (2139 KB)  ( 490 )

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