Reversibility of visual field defects through induction of brain plasticity: vision restoration, recovery and rehabilitation using alternating current stimulation

For decades visual field defects were considered irreversible because it was thought that in the visual system the regeneration potential of the neuronal tissues is low.Nevertheless,there is always some potential for partial recovery of the visual field defect that can be achieved through induction of neuroplasticity.Neuroplasticity refers to the ability of the brain to change its own functional architecture by modulating synaptic efficacy.It is maintained throughout life and just as neurological rehabilitation can improve motor coordination,visual field defects in glaucoma,diabetic retinopathy or optic neuropathy can be improved by inducing neuroplasticity.In ophthalmology many new treatment paradigms have been tested that can induce neuroplastic changes,including non-invasive alternating current stimulation.Treatment with alternating current stimulation(e.g.,30 minutes,daily for 10 days using transorbital electrodes and^10 Hz)activates the entire retina and parts of the brain.Electroencephalography and functional magnetic resonance imaging studies revealed local activation of the visual cortex,global reorganization of functional brain networks,and enhanced blood flow,which together activate neurons and their networks.The future of low vision is optimistic because vision loss is indeed,partially reversible.

VISUAL REHABILITATION IN LOW VISION PATIENTS WITH AGE-RELATED MACULAR DEGENERATION

Using optical visual aids, visual rehabilitation was performed in 14 low vision patients(25 eyes) with age-related macular degeneration. With distance aids, visual acuity improvement appeared in 24 eyes(95%) out of the 25 eyes. Twelve eyes(48%) obtained a visual acuity equal to or better than 0.4. With near visual aids, near acuity of all eyes(100%) was improved. Thirteen eyes(52%) got the near vision equal to or better than 0.5. Ten patients could read No.5 Chinese Reading Card. The reading success rat...

Early outcomes of vision and objective visual quality analysis after cataract surgery with trifocal intraocular lens implantation

AIM: To investigate the early outcomes of vision, objective visual quality and their correlation after cataract surgery with trifocal intraocular lens implantation.METHODS: The visual examination and objective visual quality analysis using Optical Quality Analysis System(OQAS) at 1 mo and 3 mo, and defocus curve examination at 3 mo were performed in 20 patients(27 eyes) after phacoemulsification combined with trifocal intraocular lens implantation surgery.RESULTS: The uncorrected distant(UD), intermediate and near visual acuity(VA) were significantly improved after surgery(P<0.001). UDVA at 1 mo after the surgery was slightly better than that after 3 mo(P=0.026). The defocus curve after 3 mo indicated that the peak of distant vision was close to 0 logMAR, and UDVA was lower than 0.3 logMAR in the range of-1.5 D to-3.0 D. The modulation transfer function(MTF) cutoff frequency, strehl ratio(SR), Optical Quality Analysis System values(OVs), includes OV100, OV20 and OV9 after the surgery were significantly better than before surgery(P<0.001), but the objective scattering index(OSI) was significantly decreased(P<0.001). UDVA at 3 mo after the surgery had correlations with MTF cutoff, OSI, OV100 and OV20(r=-0.400, 0.431,-0.437,-0.411, P=0.039, 0.025, 0.023, 0.033). The uncorrected intermediate VA after 3 mo of the surgery had correlations with OSI and OV100(r=0.478,-0.411, P=0.012, 0.033). CONCLUSION: Trifocal intraocular lens implantation can provide good distant, intermediate and near VA, and the vision shows a well correlation with objective visual quality during early surgery.

Functional outcome of the low vision aids for visual impairment secondary to central nervous system tumors in children

To assess functional outcomes of optical low vision aids(LVAs) for pediatric visual impairment due to central nervous system(CNS) tumors. A prospective case study was conducted on 15 children with history of CNS tumors with mean age of 10.47±1.85 y. Lighthouse distance, near visual acuity tests, cycloplegic refraction, reading speed measurement and visual field examination were done. Prescription of far and near LVAs followed by training sessions. LVPrasad-functional vision questionnaire was done to evaluate performance. Visual impairment was moderate(13.3%), severe(73.3%), profound(6.7%) and near blindness in 6.7%. Telescopes prescribed in 33.4%, video magnifier in 46.7%. Questionnaire scores were significantly improved for distant rather than near tasks(P≤0.05) after training. LVAs rehabilitation is an effective method of improving vision in pediatric visual defects secondary to CNS tumors.

Hybrid Visual Servoing Control for Robotic Arc Welding Based on Structured Light Vision

A novel hybrid visual servoing control method based on structured light vision is pro-posed for robotic arc welding with a general six degrees of freedom robot. It consists of a positioncontrol inner-loop in Cartesian space and two outer-loops. One is position-based visual control inCartesian space for moving in the direction of weld seam, i.e., weld seam tracking, another is image-based visual control in image space for adjustment to eliminate the errors in the process of tracking.A new Jacobian matrix from image space of the feature point on structured light stripe to Cartesianspace is provided for dierential movement of the end-e?ector. The control system model is simplifiedand its stability is discussed. An experiment of arc welding protected by gas CO2 for verifying iswell conducted.

Seam Tracking and Visual Control for Robotic Arc Welding Based on Structured Light Stereovision

A real-time arc welding robot visual control system based on a local network with a multi-level hierarchy is developed in this paper. It consists of an intelligence and human-machine interface level, a motion planning level, a motion control level and a servo control level. The last three levels form a local real-time open robot controller, which realizes motion planning and motion control of a robot. A camera calibration method based on the relative movement of the end-effector connected to a robot is proposed and a method for tracking weld seam based on the structured light stereovision is provided. Combining the parameters of the cameras and laser plane, three groups of position values in Cartesian space are obtained for each feature point in a stripe projected on the weld seam. The accurate three-dimensional position of the edge points in the weld seam can be calculated from the obtained parameters with an information fusion algorithm. By calculating the weld seam parameter from position and image data, the movement parameters of the robot used for tracking can be determined. A swing welding experiment of type V groove weld is successfully conducted, the results of which show that the system has high resolution seam tracking in real-time, and works stably and efficiently.

基于计算机视觉的采摘机器人作业优化研究

为进一步提高我国采摘机器人智能化作业水平及采摘效率,基于计算机视觉应用技术展开优化研究。以采摘机器人结构组成为设计基点,运用视觉控制核心理念建立采摘机器人视觉识别处理与控制数学模型,实施相适应的采摘路径规划和系统采摘状态输出设计。同时,进行视觉采摘验证试验,结果表明:基于计算机视觉的采摘机器人系统优化正确可行,整机综合采摘效率可达94.61%,系统识别准确率与控制精度分别相对提升了6.12%和5.25%,机器人采摘成功率可提升至95.98%。因此,将计算机视觉处理技术有效应用至采摘机器人设计改进,对于类似农业采摘与收获装备开发研究可提供创新及借鉴思路,推广价值良好。

可视化金属丝弹性模量测量平台设计

设计的可视化金属丝弹性模量测量平台,利用干涉法测量光程差原理,开发了一套干涉光斑测量装置,准确地测量出了金属材料拉伸过程中的微小形变量。引入机器视觉方法,实现了金属材料截面积的可视化测量。所搭建的传动结构可连续、稳定地施加拉力,为平台所开发的图形化操作界面,使测量过程可视化,通过观察材料表面形貌特征位移来验证拉伸变化。平台提高了实验测量精度,测量结果相对误差为3.3%。该测量平台可作为综合性实验仪器应用于大学物理实验教学当中。

基于单激光束信息的掘锚装备视觉定位方法研究

煤矿井下掘锚装备智能化是改善行业采掘失衡问题的关键,而掘锚装备的精确定位是实现其智能化的前提。与其他传统定位方法相比,基于视觉的位姿测量方法以其无接触、无累计误差的优势在煤矿井下得到了初步的应用。针对目前煤矿井下掘进工作面掘锚装备视觉定位方法存在的合作标靶结构复杂、标定繁琐的问题,结合掘进工作面原有激光指向仪特征,提出一种基于单激光束信息的掘锚装备视觉定位方法。该方法通过分析激光指向仪光斑及光束图像特征,提出了一种基于二维反正切函数拟合的激光光斑中心提取方法和基于Hough直线检测的激光束中心线提取方法,构建了基于点线特征的双目视觉位姿解算模型,得出了掘锚装备在巷道中的实时位姿。最后,为了验证提出的特征提取方法和视觉定位方法的可行性和准确性,在实验室模拟掘进工作面工况环境搭建平台进行了试验。结果表明:基于矿用激光指向仪信息的掘锚装备视觉定位方法具有较高的位姿测量精度。在50 m的测试范围内,机身位置在巷道坐标系下沿X轴、Y轴和Z轴的平均测量误差分别为25.44、58.64、31.08 mm,其最大误差分别为55.16、127.39、63.57 mm;机身姿态在巷道坐标系下的俯仰角、偏航角和横滚角的平均测量误差分别为0.22°、0.22°、0.41°,其最大误差分别为0.29°、0.37°、0.58°。满足煤矿井下巷道施工的定位精度要求。

基于改进YOLOv8和GMM图像点集匹配的双目测距方法

针对无人塔吊系统的研究需求,提出一种基于改进YOLOv8和GMM图像点集匹配的双目测距方法,对驾驶室外环境中的塔吊吊钩进行检测识别并测距。通过双目摄像头进行图像采集,引入FasterNet骨干网络和Slim-neck颈部连接层,对YOLOv8目标检测算法进行改进,有效检测画面中的塔吊吊钩并获取检测框的二维坐标信息;采用局部敏感哈希方法,并融合分阶段匹配策略,提升GMM图像点集匹配模型的匹配效率,针对检测框中的塔吊吊钩,进行特征点匹配;最后通过双目相机三角测量原理计算得出塔吊吊钩的深度信息。实验结果表明,改进后的YOLOv8算法与原算法相比,精确率P提高了2.9%,平均精度AP50提高了2.2%,模型复杂度降低了10.01 GFLops,参数量减少了3.37 M,在提升检测精度的同时实现了模型的轻量化。改进后的图像点集匹配算法与原算法相比,各个指标表现出更加良好的鲁棒性。最后在工程现场对塔吊吊钩进行识别与测距,误差可接受范围内有效完成了塔吊吊钩的检测识别与测距任务,验证了本方法的可行性。

水下航行器视觉控制技术综述

视觉控制是通过视觉信息进行环境和自身状态感知的一种控制方式,文中将该技术应用于水下航行器控制,并对不同应用场景下的相关研究进展、难点与趋势进行分析。首先介绍水下航行器视觉控制技术发展现状与任务场景,然后对水下图像增强、目标识别与位姿估计技术进行介绍,并从水下视觉动力定位与目标跟踪、水下航行器对接及水下目标抓取作业等3个任务场景,对水下航行器视觉控制技术发展现状进行总结和分析,最后梳理了水下航行器视觉控制技术的难点与发展趋势。

基于区域路标引导的月面大范围高效行驶导航技术

载人月球探测任务中,受月面环境的复杂性和车载系统配置的限制,仅依靠车载导航系统难以全自主实现精确导航,需要遥操作中心对载人车大范围移动进行智能化支持。针对载人车在复杂月面环境中进行远距离探测时的高效导航问题,提出了基于区域路标引导的月面大范围高效行驶导航方法,通过分析载人车导航相机成像区域,将全路线可视区域中的月坑构建为月面路标图;并利用载人车导航相机图像中的月坑构建导航相机路标图,使用子图匹配的方法确定载人车可视区域内的月坑和环月卫星影像中月坑的对应关系,从而完成载人车位姿的解算。仿真试验结果表明:提出方法可以实现大范围移动过程中的高效导航。

基于机器视觉的异形零件尺寸精密测量方法

针对目前异形零件尺寸测量中存在的精度低、成本高、难以实现在线测量等问题,提出一种基于Halcon的异形零件尺寸精密测量方案,包括硬件和软件算法两部分。硬件部分主要对工业相机、工业镜头和光源进行选型,并设计了测量装置。软件算法部分,首先利用Halcon对相机进行标定获得其内外参数,然后通过灰度处理、阈值分割等算子得到零件区域,接着通过区域特征筛选、最小二乘算法拟合区域最大内接圆和最小外接圆、计算两线段距离、计算两直线夹角、计算区域个数等方法实现对异形零件的齿高、外槽宽度、外槽角度、圆孔角度、外槽深度、齿数等参数的测量。最后,与高精度三坐标测量机的测量结果对比,结果表明采用本方法测量异形零件的齿高、外槽宽度和外槽深度的精度达到0.04mm,测量外槽角度和圆孔角度的精度达到0.03°。

基于虚拟现实全视野刺激下便携式眼震视图仪所测视动性眼震参数的可信度研究

目的探究便携式眼震视图仪基于虚拟现实全视野刺激下测得的视动性眼震(optokinetic nystagmus,OKN)参数的可信度。方法单纯随机选取2022年7月—2023年6月兰州大学第二医院纳入的60例健康受试者为研究对象,按照随机数表法分为两组,每组30例,对照组采用传统全视野刺激眼震视图仪,观察组采用便携式虚拟现实全视野刺激眼震视图仪,对比两组设备的OKN参数数值。结果观察组左眼眼震次数、慢相速度、快相速度、慢相时间、快相时间、增益、慢相速度/快相速度、慢相时间/快相时间为(21.26±4.26)次、(51.23±4.45)°/s、(304.52±12.26)°/s、(280.52±24.26)ms、(50.52±12.26)ms、0.74±0.26、0.18±0.04、6.05±1.26,与对照组对比,差异无统计学意义(t=0.332、0.196、0.545、0.479、0.019、0.310、0.968、0.186,P均>0.05)。两组自发性眼动试验结果对比,差异无统计学意义(P>0.05)。结论虚拟现实全视野刺激下便携式眼震视图仪用于测定OKN参数的可信度较高,与传统全视野刺激眼震视图仪所测得的OKN参数比值差异较小,并且二者所测得的自发性眼震试验结果亦无明显差异,表明便携式眼震视图仪在眼震检查方面具有较高的准确性。

民族图腾文化与现代视觉传达设计的融合

黎族图腾文化作为我国独特的非物质文化遗产,其深厚的历史底蕴和独特的艺术魅力,为现代视觉传达设计提供了丰富的灵感源泉。本文以黎族图腾文化与现代视觉传达设计的融合为切入点,明确了黎族图腾文化与现代视觉传达设计融合的具体策略,希望能够为设计师将传统文化融入现代设计之中提供一些借鉴和参考。

AI+BCI硅基碳基融合新智能的开始

我们正迎来人类发展的第四次浪潮,正处于从信息社会向人类社会-物理世界-信息空间融合的智能社会的关键转型期。近年来,计算和信息技术飞速发展,深度学习的空前普及和成功将人工智能(AI)确立为人类探索机器智能的前沿领域。与此同时,得益于器件的革命性进展和人工智能(AI)的发展,脑机接口(BCI)植入技术同样快速落地,这意味着BCI+AI碳基硅基融合的开始,然而,硅基和碳基运算的底层逻辑存在根本差异,脑的智能机制仍有待进一步探索。本研究提出的视觉认知引导的孪生AI深度网络,是由个人意识驱动的深度网络技术,通过捕捉并解析个体的思维模式和创意灵感,为每个用户量身打造独特的视觉世界。在这样的环境中,每个人都成为自己创造世界的视觉主导者,打破物质和意识的壁垒,得以展现丰富的个性和创造力。

二维主动位姿引导的单目空间姿态测量方法

针对空间物体姿态快速测量问题,以构建视觉最小系统需求为依据,研究了一种基于二维主动位姿引导的单目视觉空间姿态测量方法,建立了单目相机、二维载台与倾角仪之间的姿态测量模型,实现了空间物体的姿态角的测量。该方法以大地倾角仪坐标系统一测量系统的测量基准,由精密二维载台引导单目相机覆盖地空大视野三维空间,通过前期标定设计完成了单目相机与二维载台之间的工装校准;建立了载台坐标系、摄像机坐标系以及大地倾角仪坐标系之间的姿态测量传递模型,实现了定轴旋转双视角拍照下的空间物体的姿态解算和角度测量。构建了实验验证环境,测角实验结果表明:在系统测量基准坐标系下,其俯仰角的测量误差≤0.82°,测量相对误差≤6.1%;其横滚角的测量误差≤0.43°,测量相对误差≤3.4%。

微波视觉与SAR图像智能解译

高分辨率雷达成像技术和人工智能、大数据技术的快速发展,有力促进了雷达图像智能解译技术的进步。由于雷达传感器本身的特殊性和电磁散射成像物理的复杂性,雷达图像的解译缺乏光学图像的直观性,准确迅速识别分类的需求对雷达图像解译提出了迫切的挑战。在借鉴人脑光视觉感知机理和计算机视觉图像处理相关技术基础上,进一步融合电磁散射物理规律及其雷达成像机理,我们提出发展微波域雷达图像解译的“微波视觉”的新交叉领域研究。该文介绍微波视觉的概念与内涵,提出微波视觉认知模型,阐述其基础理论问题与技术路线,最后介绍了作者团队在相关问题上的初步研究进展。

三种不同IOL植入术后短期的视力和视觉干扰现象及脱镜率的对比

目的:对比分析单眼植入三焦点、多焦点及连续视程人工晶状体(IOL)术后短期的视力、视觉干扰现象及脱镜率。方法:回顾性分析2019-03/2022-12行超声乳化白内障吸除联合IOL植入术的白内障患者67例67眼。35例35眼植入Symfony连续视程IOL;21例21眼植入AcrySof IQ ReSTOR+3D多焦点IOL;11例11眼植入AcrySof IQ PanOptix三焦点IOL。记录术前及术后3 mo裸眼远视力(UDVA)、中视力(UIVA)、近视力(UNVA),术后3 mo离焦曲线、视觉干扰现象及脱镜率。结果:术后3 mo,三组间UDVA无差异(P>0.05);Symfony组及PanOptix组UIVA优于ReSTOR组(均P<0.01);ReSTOR组及PanOptix组UNVA优于Symfony组(均P<0.01)。离焦曲线显示,在中视力区间(-1.00--1.50 D),Symfony组视力优于ReSTOR组(P<0.05);在近视力区间(-2.50--3.50 D),ReSTOR组视力优于Symfony组(P<0.05);PanOptix组在近视力区间(-2.00--3.50 D)的视力优于Symfony组(P<0.05),同时在中视力区间(-1.00--2.00 D)的视力优于ReSTOR组(P<0.05)。三组间眩光或光晕的发生率及双眼相互干扰现象发生率均无差异(P>0.05)。PanOptix组和ReSTOR组脱镜率比Symfony组高(P<0.0167)。结论:与Symfony连续视程IOL和ReSTOR多焦点IOL相比,PanOptix三焦点IOL能够兼顾远中近视力,眩光和光晕发生率不高,脱镜率较高;单眼植入老视矫正型IOL仍需慎重。

社会科学视域下的计算机视觉研究:历史、理论与方法

计算机视觉技术发展迅速,为社会科学研究者挖掘视觉数据、研究人类行为、发现新的理论“绿洲”提供了新的路径。通过系统梳理当前与计算机视觉技术相关的社会科学文献,分析总结该领域的发轫历史、发展趋势、关注议题、相关理论概念以及研究方法,发现计算机视觉研究主要涉及的理论包括视觉效果相关理论、自我认知相关理论、社会交往相关理论和心理学相关理论四类;研究议题包括政治学、媒体传播、群体行为、区域与人口研究四大方向。在方法上,社交媒体是构成计算机视觉研究最主要的数据来源,主要分析工具包括开源工具、商业平台应用程序接口(API)和研究者自己开发的工具,涵盖12种视觉分析技术。在此基础上,从计算机视觉研究为中国社会科学跨学科研究带来的新契机、计算机视觉研究的理论困境、视觉变量的测量信度与效度以及视频数据获取和使用的伦理问题四个层面,对社会科学视域下的计算机视觉研究进行了反思。