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2014 Vol. 33, No. 2 Published: 2014-04-20 129 Mechanistic Study of Multichannel Impedance Method for Gastric Motility Measurement ZHAO Shu    SHA Hong* REN Chao Shi DOI: 10.3969/j.issn.0258-8021.2014.02.001 The aim of this work is to investigate the relationship between multichannel electrical bioimpedance signals and propagation of gastric peristalsis wave, and obtain the measurement mechanism of the electrical impedance method for gastric motility. A cylindrical volume conductor model was built using COMSOL software. The contraction of gastric circular muscle and its propagation were simulated in this model. The voltage measured from boundary of the region was obtained by solving the forward problem of electromagnetic field. An experimental device including mechanical drive unit and threelayer agar models with different conductivity was made to simulate the stomach and its contraction, and the dynamic test was performed in a salt water tank. Under the axial and radial direction current excitation pattern, the waveform of boundary voltage shows the position of circular muscle contraction and the process of peristalsis propagation. The phase difference between voltage waveform of adjacent channel exists. In experiment result, the phase differences respectively are 9 s and 6 s under axial and radial direction current excitation pattern for the agar model with conductivity of 1.35 S/m. It is correlated with the position and spacing of the measurement electrodes. The boundary voltage variations follow the same trends but in opposite direction when the electrical conductivity of gastric content is higher or lower than that of the background. The voltage sensitivity and mean value of the channels close to excitation electrodes are relatively high when using parameter δ，〖AKU-〗 and Umax/Umin for quantitative evaluation. The multichannel electrical bioimpedance signals can reflect the conductivity changes of gastric content, the contracts in different region and the peristaltic wave propagation time effectively. 2014 Vol. 33 (2): 129-138 [Abstract] ( 210 ) HTML (1 KB)  PDF (3121 KB)  ( 325 ) 139 A Knowledge Representation and Translation Method for Clinical Protocols ZHANG Yin Sheng1# LI Zhen Ye2# LI HaoMin1* ZHENG Xiang1        LU Xu Dong1     DUAN Hu DOI: 10.3969/j.issn.0258-8021.2014.02.002 Standard care based on the best clinical evidence is an effective way to enhance medical care quality and safety. However, various evidence based clinical protocols, such as standard order set and clinical pathway, are not widely accepted and used. One reason is that standard care protocols are represented as simplified medical order suites in the clinical information settings, which are not flexible enough to support personalized care and lack the capability to translate complex knowledge into actionable interventions. Thus, these standard care protocols are criticized as “cookbook medicine”. This study proposed a knowledge representation and translation method for clinical protocols. The method not only supports formally represented knowledge, but can also manage, invoke and integrate various personalized clinical decision support applications. Based on this method, a clinical knowledge translation platform is developed. The platform is integrated with clinical information system, and can recommend clinical protocols to physicians. An extensible personalized execution runtime is provided in the platform where complex knowledge is implemented as a plugin. This provides a technical solution for personalized and finegrained clinical protocols. 2014 Vol. 33 (2): 139-147 [Abstract] ( 217 ) HTML (1 KB)  PDF (2668 KB)  ( 382 ) 148 The Study on Predicting Respiratory Motion via MemoryBased Learning in Radiotherapy WAN WeiQuan1     ZHANG HuiLian2      XU ZiHai3        HE ZhiQiang1    DOI: 10.3969/j.issn.0258-8021.2014.02.003 Prediction is necessary to compensate the system latency in the realtime tracking radiation therapy for thoracic and abdominal cancers. However, because of the complexity of the breathing motion, conventional methods are far from clinical requirements. This paper proposed a memorybased learning method to predict respiratory motion. The method stores the training data in memory, then finds relevant data to answer a particular query. Furthermore, the paper adopts dynamic update the training data method and ridge regression aimed at “illcondition matrix” to greatly improve the accuracy and robustness of the algorithm. Our experiment collected ten respiratory motion data with average amplitude of 20 mm (9.2～37.8 mm) from humans’ body surface using POLARIS infrared positioning system. Using our methods (prediction horizon is 1s), mean absolute error (MAE) was reduced to 0.3 mm (0.08～0.8 mm), per estimate takes 1 ms. The results confirm that the proposed method is able to capture highly complex breathing movement accurately in real time. 2014 Vol. 33 (2): 148-154 [Abstract] ( 312 ) HTML (1 KB)  PDF (1871 KB)  ( 482 ) 155 Electrode Optimization Design of 3D Electrical Impedance Tomography System CHEN Xiao Yan1*LI HongYing1ZHAO QiuHong1    FAN WenRu 2    DOI: 10.3969/j.issn.0258-8021.2014.02.004 The aim of this work is to explore influences of electrode structure parameters on data measurement and the image reconstruction of 3D medical electrical impedance tomography (EIT) system. Considering the influences of the shape and distribution of electrodes on image reconstruction, four kinds of electrode structure are designed: square (I), round (II), concentric cylindrical combination electrode (III), and squareround combination electrode (IV). Based on QBD (quasiopposite drive between two layers) working pattern, eight different duty ratios between 0.2 and 0.7 were studied comparatively. By studying the targets as correlation coefficient of the images R, the uniformity of sensitivity field distribution P and the voltage dynamic range D, the measured data and reconstructed images are evaluated under the four electrode structures. Results showed that the four types achieved satisfied R between 0.4～0.5 exceed other DR, among them type IV gets better R and P than others types. But when DR 0.3 and 0.35, the compound electrodes (Type III and IV) were unstable with higher D than others. Images were reconstructed after regularization for five different layers from the bottom to the top including two electrodes layers, internal layer and external layers. The five targets with same conductivity but in different height (from 7.5 cm to 30 cm with equal intervals) were placed inside the tank. The images are coincident with the real distribution. The images by type IV appear less artifacts and higher imaging quality which is fitted with the targets analysis results. This research gives a light in considering the electrode configuration in three dimensional EIT with QBD working pattern and makes a foundation for 3DEIT further research. 2014 Vol. 33 (2): 155-160 [Abstract] ( 313 ) HTML (1 KB)  PDF (1719 KB)  ( 475 ) 161 Research of AntiTumor Drug Screening Cell Chip Based on 3D Cell Printing Technique ZHAO Zhan Ying    XU MingEn* SHI Ran    GUO Miao YAN Ming    XU Ying      WANG Ling DOI: 10.3969/j.issn.0258-8021.2014.02.005 There are some crucial problems in conventional drug screening systems. For example, animal models have shortcomings of species differences and long test periods; in addition, poor mimics of in vivo microenvironment results in the low accuracy of cellbased highthroughput drug screening assays. The 3D cell printing technology may provide solutions of establishing biomimetic tissue models in vitro. Moreover, the combination of 3D cell printing and cell chip provides a highly valuable tool for the efficient and accurate drug screening in vitro. In this study, a cell chip integrating several groups of IDEs, was designed and manufactured. Then, the HMSCH and HO-8910 cell lines were assembled within the gelatin/alginate mixture on the manufactured chip using 3D cell printing. The IDEs was used to detect changes in the cell impedance which reflects the cell growth, adhesion, proliferation, apoptosis and effects of drugs on the viability. Based on this cellsloaded chip, the antitumor effect or hepatoxicity of both CTX and DDP were measured respectively. Our results showed that the 3D structure could suppot the growth of HMSC-H or HO-8910 cells. The scaffold possessed pores with diameter of 200-300 μm. The change of impedance caused by the cell proliferation was precisely detected by the chip at 10.4 Hz using DMEM as electrolyte solution, 20 h later, the cell impedance increased by 69.6%. Using this chipbased in vitro drug screening model, we simultaneously detected the antitumor effect and hepatotoxicity of the drugs. Meanwhile, the efficacy of these drugs, which require hepatic metabolism for activation such as CTX, was also evaluated in the same chip. 2014 Vol. 33 (2): 161-169 [Abstract] ( 415 ) HTML (1 KB)  PDF (3133 KB)  ( 883 ) 170 SuperResolution Reconstruction for Lung 4D-CT Coronal and Sagittal Image Based on Motion Estimation XIAO Shan   WANG Ting Ting     ZHANG Yu* DOI: 10.3969/j.issn.0258-8021.2014.02.006 Lung 4D-CT plays an important role in the lung cancer radiotherapy. However, due to the great interslice thickness, the coronal and sagittal images of each 3D phase data are with low resolution. In this paper, we proposed a superresolution reconstruction method based on motion estimation to improve the image resolution of lung coronal and sagittal images. First, we analyzed the basic model of image degradation. Then, we employed motion estimation method based on full search block matching algorithm to estimate images motion vector field of different “frames”. At last, based on the motion vector field, we employed the iterative back projection (IBP) algorithm to reconstruct highresolution lung coronal and sagittal images. We used a public available dataset to evaluate the proposed algorithm, the dataset consists of 10 groups of lung 4D-CT data, each group contains 10 phases. We selected sagittal images of different phases to perform above procedure for experiments. Experimental results showed that the proposed algorithm significantly decreases edge widths（5.41±0.60, P<0.001）compared with the conventional methods, for instance, the nearest interpolation is 9.93±0.59 and bilinear interpolation is 8.04SymbolqB@069, which significantly increases image average gradient value compared with bilinear interpolation (7.49±0.75 vs 5.41±0.59, P<0.001）. Our method yields superior performance both qualitatively and quantitatively. 2014 Vol. 33 (2): 170-177 [Abstract] ( 193 ) HTML (1 KB)  PDF  (0 KB)  ( 210 ) 178 An Automatic Method for Ultrasound Probe Calibration Based on NPhantom LI WenJun       DING Hui   WANG GuangZhi* DOI: 10.3969/j.issn.0258-8021.2014.02.007 In the ultrasound guided intervention, the imaging plane is tracked using a 3D spatial tracking device, hence it is necessary to determine the transform between the ultrasound probe and the attached position sensor by calibration. The accuracy of calibration has significant impacts on the overall accuracy of ultrasound guidance. The widely used calibration method based on Nphantom requires extracting fiducial points manually in ultrasound images. The conventional manual approach is prone to subjective pickup errors and mistakes in labeling as well as timeconsuming. In this paper, an automatic method, which searches and identifies Nfiducials based on position prediction, is presented. Experimental results showed that the proposed method improves calibration precision to 0.63 mm and accuracy to 1.80 mm, compared to 1.57 mm and 2.66 mm of the conventional method, respectively. The average processing time on each frame is 0.067 s, which is much less than that of manual processing. 2014 Vol. 33 (2): 178-185 [Abstract] ( 324 ) HTML (1 KB)  PDF (1731 KB)  ( 460 ) 186 Response of Neuronal Population to High Frequency Electrical Stimulation in Rat Hippocampus FENG Zhou Yan*   YU Ying   CAO Jia Yue      GUO Zhe Shan DOI: 10.3969/j.issn.0258-8021.2014.02.008 Deep brain stimulations (DBS) have been developed for treating brain diseases such as Parkinson’s disease and epilepsy. But the mechanisms underlying DBS are not clear yet. In order to study the effects of DBS on the neural networks of brain, both orthodromic and antidromichigh frequency stimulation (HFS) were respectively applied on afferent fibers and efferent fibers of the hippocampal CA1 region in anaesthetized rats. Synchronized firings of neuronal action potential (i.e., population spike, PS) of CA1 pyramidal cells were examined. Results showed that 50 Hz orthodromicHFS induced persistent PS firings, while 100 and 200 Hz orthodromicHFS induced much less PS firings. During antidromicHFS with different frequencies, every stimulation pulse evoked a PS. However, the PS amplitude decreased gradually. The decrease of PS amplitude was more rapid with higher stimulation frequency. Taken together, the HFS of axons has excitatory effects on the neuronal populations both upstream and downstream. But the higher the stimulation frequency is, the less the excitatory effect is. These results are important for the further understanding of DBS mechanisms and for the safe and effective application of DBS in clinic. 2014 Vol. 33 (2): 186-193 [Abstract] ( 336 ) HTML (1 KB)  PDF (2526 KB)  ( 514 ) 194 Application of fMRI Activation Area Adaptive Extraction Based on Temporal SelfCorrelation Method of ICA BAI Bao Dong* LIU Jian    GUO Hong Yu DOI: 10.3969/j.issn.0258-8021.2014.02.009 The traditional ICA based activation zone detection is to analyze the correlation between the separated independent component and the reference signal. However, in practical problems, since the differences among the hemodynamic responses of the cerebral regions, the standard reference signal is often not available. Aiming at such problems, in this paper, the method of temporal selfcorrelation (TSC) combined with infomaxICA was proposed. This method processed fMRI data point by point with 5adjacent voxels based ICA, then detected the correlation between each time series period with temporal selfcorrelation algorithm and selected the maximum autocorrelation coefficient as the signal value of the voxel. After that we conversed correlation coefficient distribution to Z distribution which obey N (0, 1) by Ztransform, extracted the active regions with significant difference (a=0.05) in the statistical parametric mapping. The algorithm was applied to deal with simulation data and 12 set of real fMRI data of fist movement with both hands. Results: The method can accurately extract the active region of the simulation data. For real data processing, results of this method have a high similarity with GLM method in the spatial domain (0.465 3±0.136 8 vs 0.490 5±0.134 1) and better than GLM method in the temporal domain (0.636 4±0.011 1 vs 0.369 2±0.010 9). These results have statistical significant. Experimental results showed that, this method has good capacities of detection of functional brain activation areas and spatial orientation. 2014 Vol. 33 (2): 194-201 [Abstract] ( 237 ) HTML (1 KB)  PDF (2246 KB)  ( 423 ) 202 3D Segmentation of Breast DCE-MRI Sequence Using Spatial FCM-MRF Method ZHANG ChengJie     LiHua* DOI: 10.3969/j.issn.0258-821.2014.02.010 Breast MRI image segmentation is a challenging issue. This paper presents a 3D segmentation method, which is based on spatial FCM clustering and Markov random field. First, the MRI image was coarse segmented by spatial FCM to extract lesion contours. And then MRF segmentation was conducted to refine the result. We combined the 3D information of lesion in the MRF process by using segmentation result of contiguous slices to constraint the slice segmentation. At the same time, a membership matrix of FCM segmentation result is used for adaptive adjustment of Markov parameters in MRF segmentation process. The segmentation performance of this method was compared with that of spatial FCM, level set and fuzzy MRF on a database including 50 breast DCE-MRI examinations. Results show that average overlap rate for benign and malignant of our method is 76.4% and 75.5% respectively, compared with 68.7% and 69.5% for spatial FCM, 70.8% and 72.6% for level set method,and 72.9% and 73.6% for fuzzy MRF. It is demonstrated that our method has a better performance in accuracy. In addition, we used unsupervised evaluation method to evaluate the segmentation result of all the 175 breast DCE-MRI image sequences in the database, The uniformities of intra region (URs) for both benign and malignant lesion was more than 0.92. The differences within region (DRs) of 92% of the benign lesions and 98% of the malignant lesions were less than 150,  the differences of the inter region (DIR) of 87% of benign lesion were more than 0.25, while those of 90% of malignant lesion were over 0.3. The results demonstrated the proposed method has a good performance in segmentation accuracy. 2014 Vol. 33 (2): 202-211 [Abstract] ( 312 ) HTML (1 KB)  PDF (2748 KB)  ( 528 ) 212 Evaluating the Histocompatibility of Fishskin Collagen Sponges as Biomaterial in vivo FANG Cheng 1*WANG HaiBo2    MEI ZhiQiang1     XIAO XianJie1LIU Li1      WANG Jia DOI: 10.3969/j.issn.0258-8021.2014.01.011 This study investigated the cellular permeability, immunogenicity, inflammatory inductivity, biodegradation and deformation of grass carp skin collagen sponge  in vivo to evaluate the histocompatibility and compared with pigskin collagen sponge. Fishskin acidsoluble collagen (FA), fishskin pepsinsoluble collagen (FP) and pigskin pepsinsoluble collagen (PP) sponges were prepared by selfassembly and had highly open porous structure with microfibrous. The collage sponges with 2×2×8 mm rod shape were implanted in the adductor longus muscles (n=6 each group) of SD rats. After 1 week, three kinds of materials were penetrated by nucleated cells. There was not significant difference of the inflammatory areas between group FP (7.93±0.77 mm2) and PP (7.49±1.03 mm2), but the area of group FA (9.81±1.42 mm2) was significantly greater. The cross sections of FP pallets were deformed but the borders were clear and the fibrous networks were complete. The fibrous networks of FA pallets were disrupted and the PP pallets’ were disappeared. Assessing the amount of specific IgG antibodies in sera of KM mice (n=5 each group) immunized with collagen solution by ELISA, the OD values of group FA, FP, and PP were (0.602±0.036), (0.518±0.019) and (0.390 ± 0.085). There was only significant difference of the amount of specific IgG between group FA and PP. These results indicated that the three kinds of materials are suitable for cellular immigration. The immune and inflammatory responses to FP sponge are similar to PP sponge. The biological stability of FP sponge is superior to that of FA and PP sponges. Experimental results suggest that fishskin pepsinsoluble collagen sponge has histocompatible advantages among the three kinds of materials. 2014 Vol. 33 (2): 212-217 [Abstract] ( 213 ) HTML (1 KB)  PDF (2357 KB)  ( 433 ) 218 Development of Small Animal PET Detector YANG Kun1*LI Zhen1     YANG YongXin1    WANG WenLi1    REN QiuShi2 DOI: 10.3969/j.issn.0258-8021.2014.02.012 The performance of PET for small animal examination is largely dependent on the performance of the detector. Therefore, the designing for detector units with high resolution and high sensitivity becomes one of crucial issues in the investigation of small animal PET. This paper reviews the characteristics and performance of ring or flat panel detectors and a number of commercial PET for small animal examination. We made analysis with and summarized the development of the PET detector technology from components of a detector unit such as crystal and PMT. The development directions of determining new DOI, exploring new semiconductor detectors and designing for universal electronics are discussed as well. 2014 Vol. 33 (2): 218-226 [Abstract] ( 263 ) HTML (1 KB)  PDF (2066 KB)  ( 254 ) 227 Remodeling Models and Numerical Simulation of Bone Functional Adaptation LEI ZhouJiXin1      WANG DongMei1* WANG ChunHui2     CHEN ShanGuang2 DOI: 10.3969/j.issn.0258-8021.2014.02.013 Functional adaptation of bone occurs due to the influence and regulation of mechanical factors. Establishment of numerical model and quantitative analysis for bone remodeling process has significant clinical value. Nowadays, models developed in the literature to simulate the functional adaptation of bone fall into two classes: mechanical models and physiological models. This paper reviews bone remodeling models from several aspects, including theories, algorithms and applications. Mechanical models are able to predict bone remodeling through direct relationships between mechanical stimulus and bone structures, but no actual biological processes are considered. According to different remodeling stimuli, mechanical models mainly include mechanostat models and maintenance models. Physiological models try to unravel the role of the mechanical environment in the biological mechanisms involved in bone remodeling. Different types of cells are involved in bone remodeling process: osteoclasts, which resorb bone, and osteoblasts, which deposit bone. Based on different hypotheses, these cells are thought to work separately or as basic multicellular units. Remodeling models are normally implemented in finite element programs to enable numerical solution of problems related to bone remodeling. Based on several application examples, parametric investigation of remodeling equations is discussed as well 2014 Vol. 33 (2): 227-232 [Abstract] ( 1267 ) HTML (1 KB)  PDF (1211 KB)  ( 543 ) 233 Review of Normal Tissues Complication Probability Models ZHU Jian1,2LI BaoSheng1,2SHU HuaZhong3*BAI Tong1,2YIN Yong1,2LUO LiMin3    DE CREVOISIER Renaud4 DOI: 10.3969/j.issn.0258-8021.2014.02.014 To predict the probability of radiotherapy complications, optimize radiotherapy plans and reveal the radiobiological characteristics by normal tissue complication probability (NTCP) models are becoming important issues in the radiation oncology field recently. All of them can be achieved by identifying the NTCP model parameters with clinical and followup data. In this work, six NTCP models from literatures, model identification and comparison methods were summarized; three improved NTCP models and some other complication predictive methods were introduced as well. Issues of NTCP in individual radiotherapy were discussed and proposed from the clinical application point of view. 2014 Vol. 33 (2): 233-240 [Abstract] ( 437 ) HTML (1 KB)  PDF (1661 KB)  ( 693 ) 241 Research on Reconstruction and FEM Analysis of Laryngeal Joints ZHANG Yi    SHI TingChun*    ZHENG WenXiang DOI: 10.3969/j.issn.0258-8021.2014.02.015 2014 Vol. 33 (2): 241-245 [Abstract] ( 202 ) HTML (1 KB)  PDF (2192 KB)  ( 350 ) 246 Experimental and Simulation Study on the Effects of Enhanced External Counterpulsation on Local Stress Environment in Carotid Artery with Early Atherosclerotic Plaque DU JianHang1,3  Wu GuiFu2,3*ZHENG ZhenSheng3    DAI Gang3       FENG MingZhe3 DOI: 10.3969/j.issn.0258-8021.2014.02.016 2014 Vol. 33 (2): 246-251 [Abstract] ( 405 ) HTML (1 KB)  PDF (3025 KB)  ( 426 ) 252 The Usefulness of Individualized Spinal CT Imaging in Operation of Orthopedic Fixation Screws’ Insertion in Vertebral Pedicle CHEN DeLu DOI: 10.3969/j.issn.0258-8021.2014.02.017 2014 Vol. 33 (2): 252-256 [Abstract] ( 206 ) HTML (1 KB)  PDF (2027 KB)  ( 406 )

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