机械臂遥操作任务难度对工作负荷的影响

目的研究机械臂遥操作任务中任务难度对绩效指标、生理指标和主观工作负荷指标的影响,判断各个指标评价工作负荷的敏感性和有效性。方法招募64名受试者开展遥操作任务模拟实验,抽象化3种不同难度的机械臂任务,分别为"点对准"、"避障"、"线对准"任务,采集操作者的绩效指标、生理指标以及主观工作负荷值。结果在不同难度的机械臂遥操作任务之间,任务完成时间、操作失误次数、平移偏差、碰撞次数、扫视频率、绩效满意度和NASA-TLX量表的总负荷值存在显著性差异(P0.05)。结论机械臂遥操作任务中,绩效指标中的任务完成时间、操作失误次数、平移偏差、碰撞次数和主观工作负荷指标能够敏感地反映工作负荷的变化,可用于综合评价模型的建立。     

机械臂遥操作任务中操作者的情境意识分析

目的面向各类机械臂遥操作任务,测量并分析操作中人的情境意识(situation awareness,SA),以指导未来机械臂遥操作系统的界面设计和人员训练评价。方法在6自由度机械臂仿真操作平台上,根据有无数值信息和3种不同数量摄像机图像设置,设计两因素的2×3实验,用冻结法采集操作者SA水平、眼动数据、绩效数据。结果在提供数值辅助信息和4摄像机图像界面的组合下,操作者情境意识水平最优;通过分析SA水平与绩效数据的相关性,表明对相关情境要素的正确认知能够保证更优秀的操作绩效。结论可从提高操作者SA水平的角度来指导机械臂遥操作任务的界面设计和人员训练。     

不同立体信息水平下机械臂遥操作过程往复操作与事故的原因分析

目的基于空间站机械臂遥对接任务,从认知层面揭示其事故原因以及影响因素,为加强遥操作失误的预测、完善信息显示以及开展航天员训练提供参考依据。方法通过对24名志愿者进行基本认知能力测试以及机械臂遥对接模拟任务实验,研究不同空间立体信息水平下遥操作过程往复操作和事故的认知失误原因、失误概率以及各项认知能力与失误的关系。结果感知觉、记忆、空间关系理解和注意资源分配4种失误类型是诱发往复操作和事故的主要因素;局部信息和全局信息在遥操作中的作用不同,对减少认知失误效果明显;操作员的注意能力、运动控制能力、心理旋转能力和记忆能力越强,由于认知失误引发的往复操作以及事故越少。结论完善局部和全局信息的显示,针对性地提高航天员的认知能力,有利于保障在轨机械臂遥操作任务的安全、顺利完成。     

控制域大小及障碍对遥操作者认知和操作的影响

目的探究虚拟机械臂遥操作实验环境中控制域大小和障碍对空间站遥操作中的人因的影响。方法构建了虚拟机械臂遥操作实验环境,首先对40名受试者进行认知能力测试,综合安排实验顺序以减少个体因素的影响,然后实验设置了不同的机械臂长(1.5 m,3.0 m,6.0 m,12.0 m)和有无障碍的环境,记录对接时间、修正距离和碰撞次数3项绩效指标,使用列联表进行处理和分析。结果控制域增加对于碰撞次数减少的效果在有障碍的情况下更显著,障碍对碰撞次数的影响随臂长增加而越来越小。此外,控制域大小对对接时间的影响对于空间认知能力低者比较敏感,有无障碍对修正距离的影响对于空间认知能力低者更敏感。结论增加控制域大小可以放大操作员对有无障碍物之间的认知差异,但可以减少障碍物环境中的碰撞。具有良好空间认知能力的操作人员更易受到控制域变化的影响,空间认知能力较差的操作人员更容易受到障碍的影响。     

空间站机械臂操作绩效评价方法分析研究

掌握空间站机械臂操作,对于未来我国空间站建设等载人航天任务具有重大的意义。而科学全面的绩效评价模型有助于提高航天员机械臂操作水平和训练效果。本文通过分析当前国际空间站机械臂任务应用和操作特点,归纳和总结了包括美国航空航天局(National Aeronautics and Space Administration,NASA),麻省理工学院(Massachusetts Institute of Technology,MIT)在内的空间机械臂操作绩效的评价方法,并讨论了空间站机械臂操作绩效评价方法的利弊。机械臂操作绩效可以结合教员主观评价与客观数据,并从生理、认知等多个层面、全面科学地进行评价。     

航天员空间操作人因分析一体化仿真平台

目的为支持航天任务中航天员作业能力变化规律方面的研究,建立航天员空间操作人因分析一体化仿真平台。方法分析了该平台的系统结构,给出了控制流程及软件各部分的详细实现方法,包括认知和生物力学仿真,作业可视化,负荷预测与绩效分析等软件。结果通过手控交会对接任务作为用例,对平台功能进行了实验验证,实验结果证实了平台的可行性、有效性和实用性。结论平台的认知和生物力学模型可实现人在回路外的仿真,可对负荷与绩效进行预测及可视化显示,为进一步分析航天员在太空操作能力的变化奠定了技术基础。     

机械臂遥操作过程的视觉信息呈现方式

视觉信息作为人获取信息的主要部分,对空间遥操作任务能否顺利完成扮演极其重要的角色。对空间遥操作过程的视觉信息呈现方式进行研究梳理以及优缺点分析,对于设计符合人类操作习惯、减少操作失误以及事故发生的视觉信息呈现方式有重要意义。目前,空间遥操作中主要的信息呈现方式有摄像头视频反馈信息(人为现场监控辅助信息)、虚拟现实界面信息等。本文结合国内外研究文献,对这几种信息呈现方式进行梳理、分析和总结,并对空间遥操作过程的视觉信息呈现方式的发展前景进行了展望。     

基于ACT-R认知结构的人控交会对接任务认知集成模型

目的应用认知建模方法模拟人控交会对接任务中的人的绩效。方法采用ACT-R认知结构,模拟了感知、决策和控制三个主要的认知过程,并集成任务仿真平台,比较验证了模型的绩效和人的绩效。结果模型可以很好地预测人的过程绩效数据,但其对接精度比人的低,燃料消耗比人的少。结论认知集成模型可以模拟人的认知过程,预测任务绩效,评估任务风险,从而指导人机交互设计。     

基于运动想象脑机接口的外骨骼控制系统研究

目的为提高人机系统作业绩效,降低操作者的体力、脑力负荷,设计基于运动想象脑机接口的外骨骼控制系统。方法外骨骼控制系统采用舱外航天服上肢作为受力外骨骼,开源脑电采集板卡OpenBCI Cyton Borad充当操作者与外骨骼的控制链接,信号处理与控制软件在笔记本电脑上完成。设计想象左手、想象右手两指令的运动想象脑机接口范式,并招募5名受试者参加实验,对系统有效性进行验证。结果5名受试者同步模式识别正确率为82.5%,选取表现最佳的受试者进行异步模式测试,基于40个刺激的空白数据中检测想象状态识别正确率达到100%,指令输出延时2s左右,想象左、右手识别正确率为70%。结论实验结果验证了设计的外骨骼控制系统的有效性,并可为舱外服外骨骼控制和后续空间遥操作类任务的人机交互方式提供新的思路。     

语音技术用于提高人—机系统工效的可行性研究

本研究将汉语语音输入与输出技术应用于计算机模拟的控制任务之中,其目的是考察在人-机系统中利用语音技术来提高操作控制工效的可行性。首先我们以微型计算机为基础,利用语音输入(识别)输出(合成)装置,操纵杆和模数转换器,采用汇编和C 语言混合编程,建立了一个多功能参数可拟式人-机交互控制的实验系统。然后,利用该系统进行双自由度目标控制以及在控制过程中进行数据输入的双重作业实验。根据目标提示和数字输入的不同方式,实验设计了语显键入(SK)、字显键入(CK)、语显语入(SS)和字显语入(CS)等四种作业。实验中,作业安排的次序完全随机化,避免了因实验设计造成的“非对称转移”效应。实验结果表明,作业SK 的平均操作反应时间(ORT)比作业CK 快6.3%, 作业SS 平均ORT 比作业CS 快5.8%;四种作业中,作业SS 的平均ORT 最短,个体差异最小,作业CK 的平均ORT 最长,个体差异最大。从对被试者总体操作反应错误的统计来看,被试者对语音显示的操作反应错误率(ORER)(2.75%)比对屏幕字符显示的ORER(5.38%)要低得多,但被试者用语音输入时的ORER(2.98%)却高于键盘输入方式(其ORER 为1.13%),此系由语音识别系统的性能限制及个别被试者语音变异性所致。这些结果说明,人们对语音显示信息的反应比字符屏显的反应明显的快且对接收语音命令更习惯自然、反应更准确,在多重作业中合适地加入语音输入方式能减轻操作员的工作负荷,从而比单纯的键控方式能获得更高的效率。我们认为,语音技术在人-机系统中的应用潜力很大,对于操作员视觉、手控和认知负荷较重的任务,合理地利用语音输入输出方式替代部分视觉和手控的功能,可望减轻操作人员的工作负荷,提高操作控制工效。同时,我们还需认识到语音装置应用不利的一面,那就是语音信号本身占时长,尤其对语音识别而言,其识别时间可能比手控方式长,出错率较高,抗噪性较差。因此,其应用场合必须谨慎选择,比如,对于需快速反应或应急的场合,便不宜使用语音装置。总之,语音输入输出技术提供了视觉和手控的一种替代方式,符合人的特点,将其用于提高人-机系统工效是可行的,但尚需对人、机、环境以及作业因素的相互作用作充分考虑。     

Speech technology: present and future applications in the airborne environment

Advanced speech technology systems, specifically voice recognition and voice synthesis systems are being considered as viable solutions to the problem of distributing pilot workload in today's increasingly complex airborne environment. The U.S. Air Force has funded various projects in this area over the past few years including studies defining and establishing priorities for candidate tasks to be accomplished by voice control, as well as a developmental hardware program which entered a flight test phase in December 1982. The applications of this technology are constrained only by the rate of its evolution. Certain tasks have already been identified as excellent candidates for control by a voice system and the present hardware is capable of being configured to perform these tasks. Other tasks have been identified as potential candidates. Although these candidates are tasks which would impact pilot workload, present technology is incapable fo supporting them.     

Real‐time noise cancellation for speech acquired in interactive functional magnetic resonance imaging studies

Purpose:

To present online scanner noise cancellation for speech acquired in functional magnetic resonance imaging (fMRI) studies.

Materials and Methods:

An online active noise cancellation method for speech acquired in fMRI studies was developed. The approach consists of two automated steps: 1) creation of an MR noise template in a short “test” fMRI scan; 2) application of the template for automatic recognition and subtraction of the MR noise from the acquired microphone signal during an fMRI study. The method was applied in an experimental paradigm where a subject and an investigator communicated in an interactive verbal generation task during fMRI.

Results:

By applying online active noise cancellation, the quality of the subject's speech was substantially improved. The present approach was found to be flexible, reliable, and easy to implement, providing a method for fMRI studies that investigate the neural correlates of interactive speech communication.

Conclusion:

Using online noise cancellation it is possible to improve the quality of acquired speech in fMRI. This approach may be recommended for interactive fMRI studies. J. Magn. Reson. Imaging 2010;32:705–713. © 2010 Wiley‐Liss, Inc.     

Age-related changes of visual contribution in posture control

INTRODUCTION: Numerous studies highlighted that the role of vision in posture control increased with aging. However, these previous works only considered simple tasks consisting in "stand as still as possible" and people aged over 65 years. The present study aimed to determine changes in the role of vision in posture control during two different visual tasks for people aged between 40 and 60 years. METHOD: A stabilometric platform was used to register the effect of a modification of the visual environment on the postural behaviour. Subjects stood upright on thick foam and their attention was focused on the visual task. Two visual tasks were considered: a recognition task and a Rapid Serial Visual Presentation task. Seventy-four subjects (44 between 21 and 31 years and 31 between 44 and 60 years) took part in the study, performing both visual tasks one after the other. RESULTS: Results showed that 44-60 years old subjects were more unstable than young subjects, especially in the dark. The postural behaviour of the former was also more dependent on the properties of the visual environment. Visual contribution in postural control did not only depend on age but also on task constraints. DISCUSSION: The present study showed that the increased role of vision with age in posture control, classically investigated for people aged over 60 years, could also be highlighted in a 44-60 years old population. Furthermore, the study showed that 44-60 years old subjects' posture was more sensitive to the attentional constraints of the task than young subjects.     

举宫杯腹腔镜全子宫切除术的临床研究

目的：探讨用举宫杯行腹腔镜全子宫切除术的临床效果。方法：收集2010-03-2012-10我院收治有手术指佂的子宫肌瘤、子宫肌腺症、功能性子宫出血、CIN3患者100例（实验组50例,对照组50例）。实验组采用举宫杯行腹腔镜全子宫切除术,对照组行腹腔镜辅助阴式全子宫切除术。比较两种术式的手术时间、出血量及住院时间、并发症等情况。结果：实验组术中出血量为（50±12）ml。术后肛门排气时间为（18.0±2.0）h。术后住院时间为5d,均优于对照组（P〈0.05）。结论：举宫杯腹腔镜全子宫切除术具有创伤小、术后并发症少、恢复快及住院时间短等优点,优于腹腔镜辅助阴式全子宫切除术,值得临床推广应用。     

A manipulator system for 14-gauge large core breast biopsies inside a high-field whole-body MR scanner

PURPOSE: To investigate a robotic manipulator system for MR-guided breast biopsies inside a 1.5 T whole-body magnet. MATERIALS AND METHODS: Fourteen patients with suspicious breast lesions (diameter 18.6 +/- 12 mm) underwent biopsy. Patients with malignant findings underwent surgery afterwards and the histologic findings between biopsy and surgery were correlated. RESULTS: In five patients biopsy findings were histopathologically confirmed following open surgery. One tubular carcinoma was missed; one invasive cancer was underestimated. Seven patients with benign findings are still in the follow-up period. CONCLUSION: The study demonstrates the feasibility to perform breast biopsies inside the magnet of a whole-body MR scanner by using a manipulator system.     

成人烟雾病脑血流重建手术中不同亚型患者皮层脑电信号特征差异分析

目的 研究不同类型、不同难度的认知任务组合情况下,脑力负荷变化情况的精细表征。方法 设计一种基于逻辑运算、工作记忆和运动执行的脑力负荷诱发范式,利用该范式开展24名男性参试者参与的实验,采集参试者主观量表评分、任务绩效和脑电图（EEG）信号,并计算EEG信号多个频带的功率特征。结果 主观量表和任务绩效分析表明,计算难度、N-back 等级均能诱发出不同等级的脑力负荷;EEG信号分析表明,脑力负荷的增加伴随着前额叶theta 波增强和 alpha 波的减弱;利用支持向量机（SVM）构建脑力负荷分类模型,能实现平均75%单因素三分类正确率和81.7%的脑力负荷三分类正确率;利用逐步回归模型可实现对脑力负荷的预测。结论 EEG信号的频域特征能够反映多因素认知任务的脑力负荷变化情况,可以对认知因素水平和脑力负荷进行分类和连续预测。     

基于ARM9的舱外航天服腕部显示器的设计与实现

目的 设计基于ARM9( advanced RISC machines)的舱外航天服腕部显示器,提升舱外服信息显示能力.方法 系统采用基于ARM9核心的S3C2440A处理器作为主控芯片,同时选用液晶显示屏、电阻式触摸屏、摄像头分别作为信息显示装置、控制装置和视频采集装置.通过编写设备驱动程序和应用程序,在显示器上输出视频图像、文本信息并由触摸屏控制信息的显示.结果 根据功能要求设计了系统总体方案,完成了系统软件和显示界面的设计,液晶屏可清晰稳定地显示视频图像和文本信息,触摸屏可灵敏准确地控制信息的显示.结论 腕部显示器可以作为改进舱外航天服信息显示系统的一种可行方案.     

The effects of visual cognitive tasks on landing stability and lower extremity injury risk in high-level soccer players

BackgroundVisual cognition plays a pivotal role in sports. It is widely recognized that there is an intriguing coupling that they could affect each other through interaction between visual cognition and motor control, but few studies linked the effects of visual cognitive tasks on landing stability to postural control and injury risk.Research questionWhether visual cognitive tasks affect the landing stability and lower limb injury risk of professional soccer players?MethodsThe current study used a three-dimensional Multiple Object Tracking (MOT) task to simulate visual cognitive difficulties experienced in soccer matches. Fifteen male high-level soccer athletes (height: 181.43 ± 7.36 cm, weight: 75.37 ± 10.67 kg, training years: 10.07 ± 2.98 yr) from our school team were recruited and completed a landing action from a high platform with and without MOT tasks. Vicon infrared high-speed motion capture system and three-dimensional force measuring platform were used to collect various outcomes simultaneously.ResultsThe Time to Stabilization (TTS) during landing was significantly prolonged, while the Medial-Lateral Stability Index (MLSI), Anterior-Posterior Stability (APSI), Dynamic Postural Index Stability Index (DPSI), the trajectory lengths, and envelope area of COP during landing were also increased during MOT dual-task.DiscussionThe decline of these indicators reflected the deterioration in postural stability and greater requirements for maintaining balance which could increase the risk of injury in soccer athletes. We advocate that adequate visual attention and visual information processing might play critical roles in maintaining dynamic balance through the supraspinal neural network.     

Functional MRI of the supplementary motor area: comparison of motor and sensory tasks

PURPOSE: The purpose of this work was to assess the activation of the supplementary motor area (SMA) during simple motor, complex motor, hot sensory, and touch sensory tasks. METHOD: Functional MRI (fMRI) was performed in eight right-handed healthy volunteers. There were four tasks: simple motor, complex motor, hot sensory, and touch sensory. The number of pixels and the average percentage change of signal intensity in the activated SMA were obtained during the four tasks and then compared. RESULTS: The SMA was consistently activated on fMRI during both motor and sensory tasks. The average number of activated pixels during the complex motor task was more than the number during the hot sensory task, but the difference was not statistically significant. The average number of activated pixels during the complex motor task was greater than during the simple motor task. The average number of activated pixels during the hot sensory task was greater than during the touch sensory task. The average percentage change of signal intensity was statistically significant between the simple motor and the complex motor task. The average percentage change of signal intensity was not statistically significant between the complex motor and the hot sensory task. Conclusion: The SMA is activated in both motor and sensory tasks. The degree of activation of the SMA differs according to the type of task.