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An Experimental System Development for Head Posture Estimation Based on 3-D Images Measurement
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作者 Chen Xu Cunwei Lu 《Journal of Computer and Communications》 2014年第2期57-63,共7页
Although automobile is an indispensable vehicle to modern life, it also serves as a social problem with a big traffic accident. Among the reasons of traffic accidents, careless driving accounts for the largest part. S... Although automobile is an indispensable vehicle to modern life, it also serves as a social problem with a big traffic accident. Among the reasons of traffic accidents, careless driving accounts for the largest part. So in order to avoid the careless driving, a system which can measure the posture of a driver and warns driver to drive carefully in the case of looking aside is necessary. Although the image measurement method is used broadly, there is a problem on which measurement accuracy is influenced by environment light, makeup of the driver, etc. in the general method based on the two-dimensional image. Therefore, in this study, we propose an image measurement method to obtain the head posture of driver. First we use three-dimensional measurement method which based on the infrared pattern projection to get 3-D information of head, and then we calculate the angle for faces. In this paper, we explain the composition method of an experiment system, and the results of head posture measurement experiment. 展开更多
关键词 Careless Driving 3-d Image measurement INFRARED Pattern PROJECTION Head POSTURE ESTIMATION
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Automated Phase-measuring Profilometry of 3-D Diffuse Objects Using a Single Phase Step Method 被引量:2
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作者 ZHAO Hong,SONG Yuanhe,CHEN Wenyi,TAN Yushan (Research Institute for Laser & Infrared Application, Xi’an Jiaotong University,Xi’an 710049,CHN) 《Semiconductor Photonics and Technology》 CAS 1998年第1期25-30,35,共7页
The technique of phase measuring profilometry using a single phase step method is proposed.This method can automatically obtain phase value at each pixel by using a discret cosine transform algorithm.The method is abl... The technique of phase measuring profilometry using a single phase step method is proposed.This method can automatically obtain phase value at each pixel by using a discret cosine transform algorithm.The method is able to automatically recognize any position between depression and elevation on an object surface.Theoretical analysis and experimental verification are presented. 展开更多
关键词 Discret Cosine Transform Noncontact Optical measurement One Step Phase-shifting Phase-measuring 3-d Profilometry
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Part-level 3-D object classification with improved interpretation tree
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作者 邢薇薇 刘渭滨 袁保宗 《Journal of Southeast University(English Edition)》 EI CAS 2007年第2期221-225,共5页
For classifying unknown 3-D objects into a set of predetermined object classes, a part-level object classification method based on the improved interpretation tree is presented. The part-level representation is implem... For classifying unknown 3-D objects into a set of predetermined object classes, a part-level object classification method based on the improved interpretation tree is presented. The part-level representation is implemented, which enables a more compact shape description of 3-D objects. The proposed classification method consists of two key processing stages: the improved constrained search on an interpretation tree and the following shape similarity measure computation. By the classification method, both whole match and partial match with shape similarity ranks are achieved; especially, focus match can be accomplished, where different key parts may be labeled and all the matched models containing corresponding key parts may be obtained. A series of experiments show the effectiveness of the presented 3-D object classification method. 展开更多
关键词 3-d object classification shape match similarity measure interpretation tree
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Measurement and Compensation of Deviations of Real Tooth Surface of Spiral Bevel Gear 被引量:8
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作者 王军 王小椿 +1 位作者 姜虹 冯文军 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2003年第3期182-186,共5页
This paper presents a method for measurement of deviation of the real gear tooth surface from the theoretical one with a coordinate measurement machine and compensation of repeatable parts. By investigation of charact... This paper presents a method for measurement of deviation of the real gear tooth surface from the theoretical one with a coordinate measurement machine and compensation of repeatable parts. By investigation of characteristics of distortion of the gear tooth surface along the circle direction, the deviation is derived from distortion, and the definition of deviation with the geometrical invariability is proposed. Then the approach for determination of the location and orientation of the gear with respect to the coordinate measurement machine and the measurement way are developed. The deviation is represented with a difference surface, and an algorithm for derivation of parameters of global form deviations from the discrete points has been provided. Finally, the compensation approach is discussed. 展开更多
关键词 machine manufacture automation COMPENSATION spiral bevel gear 3-d measurement
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Field-Based Automated Survey for Extracting Tree Inventory Attributes and 3-D Models in a Forested Area
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作者 Jasmee Jaafar Juazer Rizal Abdul Hamid Roslina ldris Azman All M. Habib 《Journal of Earth Science and Engineering》 2012年第9期561-570,共10页
Acquisition of tree inventory parameters such as tree position with respect to a local reference coordinate system, tree height, dbh (diameter breast height) and other associated tree attributes is a tedious process... Acquisition of tree inventory parameters such as tree position with respect to a local reference coordinate system, tree height, dbh (diameter breast height) and other associated tree attributes is a tedious process, time consuming, costly and labour intensive. An automatic collection and processing in the field could expedite the process of tree inventory survey and data management. The advent of handheld laser equipments such as the MDL LaserAce 300, should allow rapid acquisition of tree attributes. The instrument measures distances, differences in height and horizontal bearing automatically. This paper describes a study about the automated process of retrieving tree positions, their respective attributes and the creation of 3-D model (three-dimensional model). A software developed in-house known as ASSIST (automated spatial survey information system) was utilized together with the MI)I, LaserAce 300, being the hardware component of the automated system. The capability of MDL LaserAce 9300 in extracting information regarding tree inventory attributes and the 3-D model encompassing the study area was investigated. The results were checked against the data sets acquired by a total station traversing and tacheometric survey respectively. The accuracy of the horizontal and vertical position of points gathered was critically assessed. The accuracy of the MDL LaserAce 300 was found to be less than ±2 m for both planimetric (horizontal) and vertical (height) in the construction of the 3-D model. The study demonstrates the effectiveness of a field-based automation system as a viable option to support forest application requirement. 展开更多
关键词 measuring laser tree inventory 3-d model.
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Investigation of Key Parameters for 3-D Dredging Plume Model Validation
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作者 Junsheng Jiang 《Journal of Shipping and Ocean Engineering》 2014年第5期129-139,共11页
Dredging plume dispersion studies, use dredging plume models to predict the fate of sediment plumes resulting from dredging activities and dredge spoil disposal. The model results are applied as input to environmental... Dredging plume dispersion studies, use dredging plume models to predict the fate of sediment plumes resulting from dredging activities and dredge spoil disposal. The model results are applied as input to environmental impact assessment of the proposed dredging, particularly those associated with suspended sediments and sedimentation. Model validation and performance are still not resolved because of the difficulty of site measurements and the understanding of the parameters used in the model. This paper presents a 3-D dredging plume model based on the MIKE3 software package to investigate parameters which affect the model performances. As a result of lack of site data for the public domain uses, the model scenarios are designed artificially for sensitive runs to identify the key parameters affecting plume behaviours. The factors include dredging spill rates using different dredging methods, equipment and sediment settling velocities. The influence of wave and wind effects combined with tidal forces on the sediment re-suspended rates and the advection/dispersion scales are also assessed. 展开更多
关键词 3-d dredging plume model settling velocity sediment measurement.
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3-D Shape Measurement of Complex Objects by Combining Color-Coded Fringe and Neural Networks 被引量:1
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作者 秦大辉 李中伟 +1 位作者 王从军 史玉升 《Tsinghua Science and Technology》 SCIE EI CAS 2009年第S1期66-70,共5页
A new approach for three dimensional (3-D) shape measurement was proposed based on colorcoded fringe and neural networks. By applying the phase-shift technique to fringe projection, point clouds were generated with hi... A new approach for three dimensional (3-D) shape measurement was proposed based on colorcoded fringe and neural networks. By applying the phase-shift technique to fringe projection, point clouds were generated with high spatial resolution and limited accuracy. The picture element correspondence problem was solved by using projected color-coded fringes with different orientations. Once the high accurate corresponding points were decided, high precision dense 3-D points cloud was calculated by the well trained net. High spatial resolution can be obtained by the phase-shift technique and high accuracy 3-D object point coordinates are achieved by the well trained net, which is not dependent on the camera model and will work for any type of camera. Some experiments verify the performance of this method. 展开更多
关键词 three dimensional (3-d) shape measurement color-coded fringe neural networks correspondence problem
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The Intelligent Measuring Sub-system in the Computer Integrated and Flexible Laser Processing System
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作者 LIU He-hui, YU Gang (Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期173-,共1页
Based on the computer integrated and flexible laser p rocessing system, we developed an intelligent measuring sub-system. A novel mod el has been built to compensate the deviations of the main frame-structure, and a l... Based on the computer integrated and flexible laser p rocessing system, we developed an intelligent measuring sub-system. A novel mod el has been built to compensate the deviations of the main frame-structure, and a laser tracker system is applied to calibrate the accuracy of the system. Anal yzing the characteristics of all kind surfaces of automobile outer penal moulds and dies, the surface and border to be measured and processed are classified int o four types. A 2-D adaptive measuring method based on Bzier curve and a 3 -D adaptive measuring method based on Spline curve are developed for different types of surface. During the data processing, a 3-D probe compensation method i s described in details. The control software of the sub-measuring system is des cribed. Some measuring experiments are carried out to testify the methods. 展开更多
关键词 adaptive measuring 3-d probe compensation CIMS
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High-accuracy 3-D deformation measurement method with an improved structured-light principle
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作者 GUO QinFeng WANG JinJun 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2023年第12期3450-3461,共12页
In this paper,a high-accuracy 3-D deformation measurement(HADM)method with structured light is proposed and applied to wing deformation measurement in wind tunnel experiments.The present method employs an arbitrarily ... In this paper,a high-accuracy 3-D deformation measurement(HADM)method with structured light is proposed and applied to wing deformation measurement in wind tunnel experiments.The present method employs an arbitrarily arranged fringe projector and a perpendicularly placed camera.The exact phase-height mapping using the phase differences of the projected sinusoidal fringe patterns,as well as the spatial distribution of the fringe,is accurately derived.It not only presents high feasibility but also reduces systemic uncertainties arising from deviations between the ideal model and the real-world conditions.Meanwhile,a dynamic boundary process algorithm is proposed to reduce the measurement uncertainty caused by fringe fracture near the object boundary.It is calibrated that a high accuracy with the average measurement uncertainty of 0.0237 mm is achieved,which is less than 0.01%of the side length of 25 cm of the field of view.In the wind tunnel experiments,the 3-D deformations of the elastic wing,particularly the key geometric parameters such as wing tip position,angle of attack,and dihedral angle,are well reconstructed to provide an in-depth explanation for the aerodynamic characteristics. 展开更多
关键词 3-d deformation measurement wing deformation high accuracy structured light wind tunnel tests
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Three-dimensional finite-time cooperative guidance for multiple missiles without radial velocity measurements 被引量:22
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作者 Teng LYU Chuanjiang LI +1 位作者 Yanning GUO Guangfu MA 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2019年第5期1294-1304,共11页
In order to simultaneously attack a target with impact angle constraint in threedimensional(3-D) space, a novel distributed cooperative guidance law for multiple missiles under directed communication topologies is pro... In order to simultaneously attack a target with impact angle constraint in threedimensional(3-D) space, a novel distributed cooperative guidance law for multiple missiles under directed communication topologies is proposed without radial velocity measurements. First, based on missiles-target 3-D relative motion equations, the multiple missiles cooperative guidance model with impact angle constraint is constructed. Then, in Line-of-Sight(LOS) direction, based on multiagent system cooperative control theory, one guidance law with directed topologies is designed with strict proof, which can guarantee finite time consensus of multiple missiles' impact times. Next, in elevation direction and azimuth direction of LOS, based on homogeneous system stability theory and integral sliding mode control theory, two guidance laws are proposed respectively with strict proof, which can guarantee LOS angles converge to desired values and LOS angular rates converge to zero in finite time. Finally, the effectiveness of the designed cooperative guidance law is demonstrated through simulation results. 展开更多
关键词 3-d cooperative guidance Directed communication TOPOLOGIES FINITE time Impact angle CONSTRAINT RADIAL velocity measurementS
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STM式三维nm级轮廓仪的研究 被引量:1
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作者 李文菊 张鸿海 +1 位作者 师汉民 陈日曜 《华中理工大学学报》 CSCD 北大核心 1996年第7期34-36,共3页
基于STM式三维nm级轮廓仪的检测原理、检测系统,研究了与其相关的检测技术.该轮廓仪可直接测量较大工件,扫描范围为140μm×140μm,分辨率达nm级.最后对工作台扫描非线性及扫描控制技术进行讨论,并利用多项式... 基于STM式三维nm级轮廓仪的检测原理、检测系统,研究了与其相关的检测技术.该轮廓仪可直接测量较大工件,扫描范围为140μm×140μm,分辨率达nm级.最后对工作台扫描非线性及扫描控制技术进行讨论,并利用多项式拟合法补偿工作台扫描的非线性误差,进而提出了一种平滑反馈扫描技术. 展开更多
关键词 检测 扫描隧道显微镜 轮廓仪
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微型牙齿三维测量技术与系统 被引量:3
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作者 马超 李中伟 +2 位作者 王从军 钟凯 史玉升 《装备制造技术》 2012年第2期30-34,共5页
为方便扫描牙齿等微小物体的三维形貌,设计了一套专门用于口腔内部直接测量的牙齿三维扫描系统,该系统利用数字光栅投影仪投射结构光,通过远心成像镜头将光栅图像缩小,经光纤传像束传输投射到待测微小物体上,同时采用电子内窥镜获取图像... 为方便扫描牙齿等微小物体的三维形貌,设计了一套专门用于口腔内部直接测量的牙齿三维扫描系统,该系统利用数字光栅投影仪投射结构光,通过远心成像镜头将光栅图像缩小,经光纤传像束传输投射到待测微小物体上,同时采用电子内窥镜获取图像,最后重构出物体的三维形貌。实验证明,该系统切实可行,满足牙齿扫描的微型化、直接化、灵活性的需求,拓展了结构光微测量三维形貌的适用范围。 展开更多
关键词 结构光 远心成像镜头 光纤传像束 电子内窥镜 微测量 三维形貌
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Principle of Coordinates Acquisition Based on Single Camera 被引量:5
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作者 黄桂平 叶声华 《Transactions of Tianjin University》 EI CAS 2005年第1期49-52,共4页
The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets ... The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets and one tip with known coordinates, the single camera′s orientation and location can be calculated. After orientation, the global coordinate system is obtained. During measurement, the camera is fixed firstly, then the AMP is held and the feature point is touched.The camera is triggered lastly. The position and orientation of the AMP are therefore calculated from the size and position of its image on the sensor. Since the tip point of AMP has known relation with the embedded targets, the feature point can be measured. Tests show that the accuracy of length measurement is 0.2 mm and accuracy for flatness measurement in XSY-plane is 0.1 mm. 展开更多
关键词 3-d coordinates acquisition single camera collinear equation spatial resection aided measuring probe
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计算机微视觉的三维显微测试及构形系统的研究
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作者 刘鹏飞 俞必强 翁海珊 《机械》 2008年第1期11-13,共3页
微结构三维显微测量是研究微加工工艺和微尺度结构特性的主要测试手段。一种基于计算机微视觉的方法被提出用来对三维微结构进行显微测量。对微结构测试及构形系统的基本原理进行了研究,构建了微结构测试及构形系统的硬件和软件平台。... 微结构三维显微测量是研究微加工工艺和微尺度结构特性的主要测试手段。一种基于计算机微视觉的方法被提出用来对三维微结构进行显微测量。对微结构测试及构形系统的基本原理进行了研究,构建了微结构测试及构形系统的硬件和软件平台。从而实现了在光学显微镜下对微结构的三维观测[0]。通过运用微结构测试及构形系统的硬件平台实现了对微结构高分辨率的观察测量、三维精确运动控制以及水平与竖直方向的精确制动。通过软件平台完成了对微结构的三维重构。课题利用微结构测试及构形系统对微结构进行了测试及重构。通过实验,证明了理论研究和系统的可行性,该研究在微结构的测试方面具有较大的理论意义和实用价值。 展开更多
关键词 计算机微视觉 微结构 三维显微测量
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Quality measure of color images based on properties ofvision psychology and color distortion in MPEG-21 被引量:2
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作者 CHEN Qiang CHEN He-xin SANG Ai-jun 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2007年第2期112-119,共8页
In this article, a new way to evaluate the quality of color images is proposed, in which the properties of human vision psychology, objective fidelity, edge information, and color distortion will be combined through u... In this article, a new way to evaluate the quality of color images is proposed, in which the properties of human vision psychology, objective fidelity, edge information, and color distortion will be combined through utilizing 3-D matrix transform. There exists color redundancy and structural similarity between three different frames of a color image, the definition of vision properties will be measured by 3-D submatrix integration transform (SIT), in which three color components are integrated into one model and color redundancy can be exploited fully. The simulation results show that the measure index is very effective and objective in accord with vision properties. 展开更多
关键词 color image quality measure vision property 3-d submatrix integration transform PSNR MPEG-21
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复杂微结构三维形貌测量方法的研究 被引量:9
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作者 胡春光 胡晓东 +2 位作者 徐临燕 郭彤 胡小唐 《光电子.激光》 EI CAS CSCD 北大核心 2006年第1期98-101,共4页
微结构三维形貌测量是研究微加工工艺和微尺寸特性的重要测试内容。本文提出一种基于相移显微干涉术、利用干涉图建立二维结构模板指导相位展开的新方法,它不仅适用于静态测量,而且能应用于在动态测量中,特别是微机电系统(MEMS)器件的... 微结构三维形貌测量是研究微加工工艺和微尺寸特性的重要测试内容。本文提出一种基于相移显微干涉术、利用干涉图建立二维结构模板指导相位展开的新方法,它不仅适用于静态测量,而且能应用于在动态测量中,特别是微机电系统(MEMS)器件的运动测量。以微谐振器为测试器件,对其运动梳齿结构进行了静态三维形貌测量,实验的离面理论测量精度优于0.5 nm,测试结构内部的面内理论测量精度优于0.5μm,而边缘尺寸因受到边缘提取方法的影响,其测量精度仅在μm量级。对该方法的缺点和发展方向做了探讨。 展开更多
关键词 微结构 三维形貌测量 相移显微干涉术 二维结构模板 生长算法
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Applications of Digital Correlation Method to Structure Inspection 被引量:4
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作者 陈俊达 金观昌 孟利波 《Tsinghua Science and Technology》 SCIE EI CAS 2007年第3期237-243,共7页
In structure inspections, applications of optical techniques are rare, but the advantages of a noncontact, full field technique using a simple apparatus are attractive. The main requirements for structure inspection a... In structure inspections, applications of optical techniques are rare, but the advantages of a noncontact, full field technique using a simple apparatus are attractive. The main requirements for structure inspection are the full-field strain measurement with the required precision and on-site measurement ability. The digital correlation method (DCM), a new optical deformation measurement tool, can satisfy all of the requirements for structure inspection. A smoothing algorithm which can greatly improve the strain measurement precision, and a 3-D DCM have been developed in this paper. For verifying this improvement, a comparison of strain measurements by computer-simulated speckle images has been carried out. Additionally, three structure inspection examples that cover typical materials and structure styles are presented: the interface shear stress distribution for reinforced concrete piles bedded on rock, the 3-D strain distribution of a composite vessel structure, and stresses in a hookup that connects two steel bridge structures. All the examples show that the new structural inspection tool is exemplary and illustrates the obvious advantages of this optical non-destructive technique. 展开更多
关键词 structure inspection optical non-destructive technique digital correlation method (DCM) 3-d strain measurements
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电针足三里对严重烫伤致大鼠急性肺损伤的影响 被引量:11
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作者 宋学敏 王焱林 +5 位作者 李建国 梁辉 李兰芳 周青 张宗泽 王成夭 《中华麻醉学杂志》 CAS CSCD 北大核心 2010年第4期469-472,共4页
目的 探讨电针足三里对严重烫伤致大鼠急性肺损伤的影响.方法 雄性SD大鼠40只,体重200~250 g,随机分为5组(n=8):对照组、烫伤组、足三里组、非经非穴组和α-银环蛇毒素组(α-BGT组).对照组尾静脉注射生理盐水1 ml.烫伤组、足三里... 目的 探讨电针足三里对严重烫伤致大鼠急性肺损伤的影响.方法 雄性SD大鼠40只,体重200~250 g,随机分为5组(n=8):对照组、烫伤组、足三里组、非经非穴组和α-银环蛇毒素组(α-BGT组).对照组尾静脉注射生理盐水1 ml.烫伤组、足三里组、非经非穴组和α-BGT组先制备30%总体表面积Ⅲ度烫伤模型,然后烫伤组尾静脉注射生理盐水1 ml;足三里组于双侧足三里穴垂直进针7 mm,给予脉冲电流(电压3V,电流2ms,频率3 Hz)持续刺激12 mim,间隔8 h刺激1次,持续2 d;非经非穴组于双侧足三里穴旁5mm处给予脉冲刺激,方法同足三里组;α-BGT组尾静脉注射α-BGT 1.0 μg/kg,再于双侧足三里穴给予脉冲刺激,方法同足三里组.各组处理结束后,处死大鼠,取肺组织,光镜下观察病理学结果,电镜下观察超微结构,采用ELISA法测定肺组织高迁移率族蛋白B1(HMGBl)含量,采用免疫组化法测定HMGBl蛋白表达,采用RT-PCR法测定HMGBl mRNA表达.结果 烫伤组肺组织光镜下可见肺泡壁崩解,泡内大量渗出液,间质水肿、肥厚和增生,伴大量炎性细胞浸润;电镜下可见细胞核形态不规则,核膜僵硬,部分凸凹不平和核溶解,胞质内板层小体明显减少,肺组织病理损伤程度较对照组减轻.与对照组比较,烫伤组、非经非穴组和α-BGT组肺组织HMGBl含量升高,HMGBl蛋白及其mRNA的表达上调(P〈0.05),足三里组各指标差异无统计学意义(P〉0.05);与烫伤组比较,足三里组肺组织HMGBl含量降低,HMGBl蛋白及其mRNA的表达下调,非经非穴组和α-BGT组肺组织HMGBl mRNA表达下调(P〈0.05);与足三里组比较,非经非穴组和α-BGT组肺组织HMGBl含量升高,HMGBl蛋白及其mRNA的表达上调(P〈0.05).结论 电针足三里可减轻严重烫伤致大鼠急性肺损伤,其机制与激活含α7亚基N型胆碱能受体介导的胆碱能抗炎通路,抑制肺组织HMGBl的表达有关. 展开更多
关键词 足三里 烧伤 呼吸窘迫综合征 成人
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