Name: force and position control in humans - the role of augmented feedback
Uploaded: 2016-06-19T13:00:00.000+00:00
Duration: 6 min 31 s
Description: Watch this Scientific Journal Video about Force and Position Control in Humans - The Role of Augmented Feedback at JoVE.com

The authors have no acknowledgements.

这里描述的协议，随后弗赖堡大学伦理委员会的指导方针，是符合赫尔辛基宣言（1964）。 1.伦理批准 - 学科教学<ol><li>实际的实验前，指导有关研究和潜在的风险因素的目的，所有科目。当施加经颅磁刺激（TMS）外，还有一些医疗风险，包括癫痫发作，在眼睛和/或头部的金属植入物，心血管系统和妊娠疾病的任何历史。排除任何受到肯定，从研究这些危险因素之一。 </li><li>仅包含在研究健康人。排除任何神经，精神和/或矫形疾病患者。 </li></ol> 2.除准备<ol><li>主题布局<ol><li>纵观整个实验中，受试者座椅在舒适的椅子。固定头采用铸造拥抱脖子，确保稳定的头部位置，避免头部相对于TMS线圈的任何运动的参与者。 </li><li>放置受试者的右臂的定制扶手，以尽量减少手腕的运动。固定被检者的右手食指来安装到机器人的臂上的夹板。对准机器人手臂用右手的metacarpophangeal关节的旋转轴线，以使接头中心的机器人的旋转中心相匹配。 </li></ol></li><li>强制录音<ol><li>由安装在机器人臂上的扭矩测量由受试者所施加的力和测量所述机器人臂（对应于食指的位置）由连接到机器人22的旋转轴线的电位器的位置。 </li></ol></li><li>肌电图（EMG） <ol><li>使用表面电极的双极配置，以测量由TMS诱发电生理反应以及muscula- [R活化受试者产生的。 <ol><li>右手在第一背鳍间肌（FDI）的电极连接到皮肤和拇短展肌（APB）之前，刮胡子受试者的皮肤，然后轻轻用砂纸或打磨胶打磨它，并丙醇消毒吗。 </li><li>在此之后，附加自粘肌电电极在皮肤上过外国直接投资和APB的肌腹。将一个额外的参比电极在同一手臂的尺骨鹰嘴。 </li><li>所有电极电缆连接到EMG放大器和一个模拟 - 数字转换器。放大肌电信号（×1,000），带通滤波器（10 - 1000赫兹），并在4 kHz采样。存储离线分析的肌电信号。 </li></ol></li></ol></li><li> TMS <ol><li>使用连接到TMS刺激8线圈的数字刺激对侧运动皮层手区。 </li><li>发现线圈相对的最佳位置到头皮用于引发运动诱发的FDI肌肉电位（MEPS）由映射过程: <ol><li>线圈放置约0.5厘米前方顶点并用与在相对于矢形面45°逆时针指向，诱导的电流在线圈的中心的后前流手柄中线。 </li><li>在开始的时候，选择一个小的刺激（ 如低于30％的最大刺激输出，MSO）强度才能适应磁脉冲的主题。 </li><li>随后，增加在小步骤的刺激强度，例如2 - 3％最大刺激输出（MSO）和，以便找到用于刺激FDI最佳站点（热点）移动线圈在额叶-喙和内 - 外方向肌肉。热点被定义为能在给定的刺激强度来观察的最大的MEP的地方。 </li></ol></li><li>找到FDI热点后，决定休息运动阈值（MT）作为minimu需要米力度，以唤起MEP的峰-峰值幅度在EMG大于50μV的五分之三的连续试验18。检查电脑屏幕上显示在线的欧洲议会议员的大小。 </li><li>用1.0 * MT引发的MEP后，在不断减少的TMS机的刺激强度在2％的MSO的步骤，直到该MEP不再能观察到正在进行的肌肉活动的肌抑制变得明显。 注:为了描绘TMS诱发EMG抑制有必要采用大量的刺激（见第5章"数据处理"）的</li></ol></li></ol> 3.反馈法<ol><li>把参与者分成三组（PF，FF，CON）。 </li><li>在试验中有一半来自指示位置反馈组（PF）的主题，通过按压机器人装置移动食指当收到有关食指（位置反馈）的位置反馈。&lt;/ LI&gt; <li>在试验中的另一半，指导科目收到反馈关于作用力而移动机械手设备（力反馈）。 注:在现实中，然而，他们总能收到同样的反馈（位置反馈）。 </li><li>从指导力反馈组（FF）患者接受力反馈在试验的一半，另一半接受位置反馈。 注:事实上，这组只提供力反馈。 </li><li>不要指示有关的反馈源对照组（CON）。注:对照组接受另一半迫使他们的审判的一半和位置反馈意见。 </li><li>随机改变会议的顺序，也就是试验是否符合力或位置反馈开始，在所有群体。 </li><li>可视地显示的力和一个计算机屏幕上的位置反馈中的受试者前放置1μm以下。 </li><li>在每种条件下，呈现对应于目标行被检者的个体最大随意力的30％，或30％的最大自主收缩力（MVC）的食指的手指的角度，在计算机屏幕上，并指示受试者对所述目标线紧密地匹配越好。 </li></ol> 4.最大等长收缩力<ol><li>主题准备（EMG）后，执行三个等距最大随意收缩（MVC），由在长力最大超过3秒的时间跨度逐渐增加，从零2秒20,21举行的最大力量。 </li><li>口头鼓励的主题，以达到最大的力量。每次试验后，让受试者休息90秒钟，以避免疲劳。 </li></ol> 5.实验步骤<ol><li>疲劳电机任务 - 持续收缩。 注:疲劳的任务包括在不同天执行了两个持续收缩。 <ol><li>指导受试者匹配30％MVC的目标线尽可能长的时间与对应于所施加的力或他们的手指的相应于30％的MVC的力水平的位置的线。 注:因此，位置反馈情况（PF-组）在目标线对应手指的角度当受试者匹配30％MVC的动力水平。 </li><li>要求受试者保持收缩，直到任务失败，它被定义为主体不再能够在一段5秒（FF-组）持有目标力的5％，窗口内的目标力点。对于PF基团，定义任务失败当参与者无法维持所需的目标角的5％以内的手指的角度为5秒12,23。 </li><li>确保这两个持续收缩是由至少48小时分离。 </li></ol></li><li> TMS协议 注:亚阈值TMS实验在不同天进行到了疲劳的收缩。这是重要的，因为疲劳具有影响在EMG镇压subTMS 24,25这样的力量和位置之间的差异引起的无法明确。从TMS测量分离疲劳收缩具有的优点是在肌电抑制差异现在可以清楚地归因于反馈的不同的解释，但具有这样的结果不能直接被链接到在时间疲劳的差异的限制的持续收缩。 <ol><li>使用进行TMS实验的一部分（见第3章"反馈法"），在除疲劳实验单独的场合。最初，遵循完全相同的程序作为疲劳收缩（如 MVC收缩），但是这一次，要求被试只要只能作为TMS刺激持续保持收缩。因此，宫缩不是易疲劳，只在TMS试验期间保持约100秒。 </li><li>提供的三间3分钟休息ALS减少疲劳任何偏见。 </li></ol></li></ol> 6.数据处理<ol><li> TMS <ol><li>应用共100次扫描，50扫描与和50扫描的无刺激，具有刺激间间隔范围从0.8到1.1小号20,21,25,26。此短刺激间隔可确保受试者不需要持有宫缩太久所以疲劳影响可以被最小化。 </li><li>要分析如果TMS刺激引起了便利（MEP）或EMG抑制，减去50扫描的整流，然后平均50扫描与刺激（刺激EMG）无刺激（对照EMG）20,21,25-27。 注意:肌电抑制的发作被定义为时间点，其中用于与刺激扫描平均EMG小于在TMS脉冲之后的20至50毫秒的时间帧的至少4毫秒的控制肌电图。抑制的结束被定义为t他时瞬间刺激EMG大于至少1毫秒控制肌电图和抑制的程度计算百分比变化（控制刺激/平均值控制 * 100）。 </li><li>使用未经TMS刺激扫描为背景肌电活化的计算和平均它们在相同时间窗与刺激20,21,25,26的试验。 </li></ol></li><li> 肌电图 <ol><li>通过计算记录在0.5秒的时间窗口围绕在MVC测试20,21测得的峰值力的根均方值确定最大EMG活动。 </li><li>对于持续收缩，通过构建其中整流肌电的根均方计算并归一化到MVC试验20,21期间获得的EMG活动8秒长箱分析EMG。 </li></ol></li></ol>

The authors have nothing to disclose.

如果追加反馈的解释影响时间持续次最大收缩疲劳和初级运动皮层的神经处理本研究探讨。结果表明，只要参与者解释反馈位置反馈（相对于力反馈），时间疲劳是显著较短，运动皮层（所引起的subTMS肌电抑制量来衡量）的抑制活性越大。作为任务没有条件之间变化，目前的研究结果表明在根据反馈的源的解释力和位置的控制策略的差异。如定时28或反馈而本研究的频率29,30集中?...

感官反馈是执行动作的关键。日常活动在没有本体1的几乎不可能的。此外，运动学习是由本体集成2个或皮肤感觉3的影响。健康人与完整感觉能够加权从各种感觉源所产生的感觉输入，以满足具体情况的需要4。这种感觉使称重人类具有精度高，即使感官信息的某些方面是不可靠的，甚至没有执行艰难的任务（ 例如 ，在黑暗中行走或闭眼）。 此外，各种证据表明，可增强（或附加的）反馈进一步提高电动机控制和/或运动学习。增强反馈提供通过其可以添加到任务固有（感觉）从感官产生的反馈外部源的其他信息系统5,6。特别是增强反馈的电机控制和学习内容的影响是极大的兴趣，在最近几年。其中一个问题解决了人类如何控制力量和位置7,8。警方初步调查认定使用任一位置或强制加载符合反馈和分歧，持续次最大收缩疲劳时间差异（ 例如，9-12）。当受试者提供力反馈，时间持续收缩乏力比较时提供位置反馈给显著更长的时间。观察到各种不同的肌肉和肢体位置和若干神经肌肉机制同样的现象，包括马达单元招募更大的速率和位置控制的收缩（综述13）中在H反射面积更大的减少。然而，在这些研究中，不仅在视觉反馈，而且物理Ç肌肉收缩的特性（ 即 ，测量装置的合规性）的改变。因此，我们最近进行的一项研究不改变规定，但只增加反馈，并提供了证据的持续收缩亚最大过程中提供武力和单独位置反馈可能会导致初级运动皮层（M1）内的抑制活性的差异。这是使用已知在皮质水平14，即低于阈值的经颅磁刺激（subTMS）纯粹充当刺激技术所示。不像阈上TMS，由subTMS诱发的反应，不会被脊柱α-运动神经元和兴奋性兴奋性神经元和/或皮质细胞15-17的兴奋性，但仅通过抑制皮质内神经元的兴奋调制。这种刺激技术背后的假设机理是，它是在强度施加低于阈值，以唤起一个运动诱发电位（MEP）。它表明在具有这种类型的刺激不产生任何下行活动宫颈水平植入电极的患者，但是它主要激活初级运动皮质14,18,19内抑制性。抑制性的本激活导致正在进行的EMG活动的降低，并且可以通过相对于无刺激在试验中获得的EMG活动肌电抑制量进行定量。在这方面，我们发现，受试者在他们与试验中，力反馈提供了20相比接收到的位置反馈试验显示显著更大的抑制活性。此外，我们还发现，不仅不同的反馈方式（力与位置控制），而且反馈的诠释呈现会 ​​对行为和神经生理学数据非常类似的效果。更具体地，当我们让参与者接收position反馈（即使它是力反馈），他们也不仅表现更短的时间疲劳，也抑制M1活动21的水平提高。使用其中总是提供相同的反馈，但用约其内容不同的信息的方法具有的优点是，任务的限制， 即，反馈的介绍，反馈的增益，或负载的顺应性是条件，以便之间相同在性能和神经活动的差异是清楚的相关中的反馈的不同解释，并且不通过不同的测试条件下偏置。因此，目前的研究调查一个的不同的解释，并且在同一反馈是否影响持续次最大收缩的持续时间，进而对主运动皮层的抑制活性的激活产生影响。

<table><tbody><tr><td>torquemeter</td><td>LCB 130, ME-Mebsysteme, Neuendorf, Germany</td><td></td><td>Part of robotic device built for force and position recordings</td></tr><tr><td>potentiometer</td><td>type 120574, Megatron, Putzbrunn, Germany</td><td></td><td>Part of robotic device built for force and position recordings</td></tr><tr><td>EMG electrodes</td><td>Blue sensor P, Ambu, Bad Nauheim, Germany</td><td></td><td></td></tr><tr><td>TMS coil</td><td>Magstim</td><td></td><td></td></tr><tr><td>TMS machine</td><td>Magstim Company Ltd., Whitland, UK</td><td></td><td></td></tr><tr><td>Recording software</td><td>Labview-Based</td><td></td><td>custom written software</td></tr></tbody></table>

force and position control in humans - the role of augmented feedback

During motor behaviour, humans interact with the environment by for example manipulating objects and this is only possible because sensory feedback is constantly integrated into the central nervous system and these sensory inputs need to be weighted in order meet the task specific goals. Additional feedback presented as augmented feedback was shown to have an impact on motor control and motor learning. A number of studies investigated whether force or position feedback has an influence on motor control and neural activation. However, as in the previous studies the presentation of the force and position feedback was always identical, a recent study assessed whether not only the content but also the interpretation of the feedback has an influence on the time to fatigue of a sustained submaximal contraction and the (inhibitory) activity of the primary motor cortex using subthreshold transcranial magnetic stimulation. This paper describes one possible way to investigate the influence of the interpretation of feedback on motor behaviour by investigating the time to fatigue of submaximal sustained contractions together with the neuromuscular adaptations that can be investigated using surface EMG. Furthermore, the current protocol also describes how motor cortical (inhibitory) activity can be investigated using subthreshold TMS, a method known to act solely on the cortical level. The results show that when participants interpret the feedback as position feedback, they display a significantly shorter time to fatigue of a submaximal sustained contraction. Furthermore, subjects also displayed an increased inhibitory activity of the primary cortex when they believed to receive position feedback compared when they believed to receive force feedback. Accordingly, the results show that interpretation of feedback results in differences on a behavioural level (time to fatigue) that is also reflected in interpretation-specific differences in the amount of inhibitory M1 activity.

反馈解读 在此处描述的过程中，受试者中的方式，他们在他们的试验中一半认为已经接收到的位置反馈被指示，并在试验中的另一半已收到的力反馈。事实上，他们在试验中，因为他们的PF-集团始终获得位置反馈和FF-集团始终接受力反馈的一半被欺骗。 使用这种方法具有?...

Watch this Scientific Journal Video about Force and Position Control in Humans - The Role of Augmented Feedback at JoVE.com

Force and Position Control in Humans - The Role of Augmented Feedback

Controlling an identical movement with position or force feedback results in different neural activation and motor behavior. This protocol describes how to investigate behavioral changes by looking at neuromuscular fatigue and how to evaluate motor cortical (inhibitory) activity using subthreshold TMS with respect to the interpretation of augmented feedback.

力和位置控制人类 - 增强反馈的作用

During motor behaviour, humans interact with the environment by for example manipulating objects and this is only possible because sensory feedback is ...

force-and-position-control-in-humans-the-role-of-augmented-feedback

Research

JoVE Journal

Behavior

7.8K 次观看.  University of Freiburg. Controlling an identical movement with position or force feedback results in different neural activation and motor behavior. This protocol describes how to investigate behavioral changes by looking at neuromuscular fatigue and how to evaluate motor cortical (inhibitory) activity using subthreshold TMS with respect to the interpretation of augmented feedback. 

视频: Force and Position Control in Humans - The Role of Augmented Feedback

Haptic/Graphic Rehabilitation: Integrating a Robot into a Virtual Environment Library and Applying it to Stroke Therapy

Recent research that tests interactive devices for prolonged therapy practice has revealed new prospects for robotics combined with graphical and other forms of biofeedback. Previous human-robot interactive systems have required different software commands to be implemented for each robot leading to unnecessary developmental overhead time each time a new system becomes available. For example, when a haptic/graphic virtual reality environment has been coded for one specific robot to provide haptic feedback, that specific robot would not be able to be traded for another robot without recoding the program. However, recent efforts in the open source community have proposed a wrapper class approach that can elicit nearly identical responses regardless of the robot used. The result can lead researchers across the globe to perform similar experiments using shared code. Therefore modular "switching out"of one robot for another would not affect development time. In this paper, we outline the successful creation and implementation of a wrapper class for one robot into the open-source H3DAPI, which integrates the software commands most commonly used by all robots.

Recently, a vast amount of prospects have come available for human-robot interactive systems. In this paper we outline the integration of a new robotic device with open source software that can rapidly make possible a library of interactive functionality. We then outline a clinical application for a neurorehabilitation application.

触觉/图形康复：整合成一个虚拟的环境下图书馆的机器人，它应用于中风治疗

Recent research that tests interactive devices for prolonged therapy practice has revealed new prospects for robotics combined with graphical and other ...

科研

生物工程

A Structured Rehabilitation Protocol for Improved Multifunctional Prosthetic Control: A Case Study

Advances in robotic systems have resulted in prostheses for the upper limb that can produce multifunctional movements. However, these sophisticated systems require upper limb amputees to learn complex control schemes. Humans have the ability to learn new movements through imitation and other learning strategies. This protocol describes a structured rehabilitation method, which includes imitation, repetition, and reinforcement learning, and aims to assess if this method can improve multifunctional prosthetic control. A left below elbow amputee, with 4 years of experience in prosthetic use, took part in this case study. The prosthesis used was a Michelangelo hand with wrist rotation, and the added features of wrist flexion and extension, which allowed more combinations of hand movements. The participant&#8217;s Southampton Hand Assessment Procedure score improved from 58 to 71 following structured training. This suggests that a structured training protocol of imitation, repetition and reinforcement may have a role in learning to control a new prosthetic hand. A larger clinical study is however required to support these findings.

As prosthetic development moves towards the goal of natural control, harnessing amputees&#8217; inherent ability to learn new motor skills may enable proficiency. This manuscript describes a structured rehabilitation protocol, which includes imitation, repetition, and reinforcement learning strategies, for improved multifunctional prosthetic control.

结构化的康复协议改进的多功能假肢控制:一个案例研究

Advances in robotic systems have resulted in prostheses for the upper limb that can produce multifunctional movements. However, these sophisticated ...

行为学

Movement Retraining using Real-time Feedback of Performance

Any modification of movement - especially movement patterns that have been honed over a number of years - requires re-organization of the neuromuscular patterns responsible for governing the movement performance. This motor learning can be enhanced through a number of methods that are utilized in research and clinical settings alike. In general, verbal feedback of performance in real-time or knowledge of results following movement is commonly used clinically as a preliminary means of instilling motor learning. Depending on patient preference and learning style, visual feedback (e.g. through use of a mirror or different types of video) or proprioceptive guidance utilizing therapist touch, are used to supplement verbal instructions from the therapist. Indeed, a combination of these forms of feedback is commonplace in the clinical setting to facilitate motor learning and optimize outcomes.
Laboratory-based, quantitative motion analysis has been a mainstay in research settings to provide accurate and objective analysis of a variety of movements in healthy and injured populations. While the actual mechanisms of capturing the movements may differ, all current motion analysis systems rely on the ability to track the movement of body segments and joints and to use established equations of motion to quantify key movement patterns. Due to limitations in acquisition and processing speed, analysis and description of the movements has traditionally occurred offline after completion of a given testing session.
This paper will highlight a new supplement to standard motion analysis techniques that relies on the near instantaneous assessment and quantification of movement patterns and the display of specific movement characteristics to the patient during a movement analysis session. As a result, this novel technique can provide a new method of feedback delivery that has advantages over currently used feedback methods.

Retraining abnormal movement patterns following injury or disease is a key component of physical rehabilitation. Recent advances in technology have permitted accurate assessment of movement during a variety of tasks, with near instantaneous quantification of results. This provides new opportunities for modification of faulty movement patterns in real time.

的运动再培训采用实时反馈的性能

Any modification of movement - especially movement patterns that have been honed over a number of years - requires re-organization of the neuromuscular ...

医学

Characterization of the Sense of Agency over the Actions of Neural-machine Interface-operated Prostheses

This work describes a methodological framework that can be used to explicitly and implicitly characterize the sense of agency developed over the neural-machine interface (NMI) control of sensate virtual or robotic prosthetic hands. The formation of agency is fundamental in distinguishing the actions that we perform with our limbs as being our own. By striving to incorporate advanced upper-limb prostheses into these same perceptual mechanisms, we can begin to integrate an artificial limb more closely into the user&#39;s existing cognitive framework for limb control. This has important implications in promoting user acceptance, use, and effective control of advanced upper-limb prostheses. In this protocol, participants control a virtual prosthetic hand and receive kinesthetic sensory feedback through their preexisting NMIs. A series of virtual grasping tasks are performed and perturbations are systematically introduced to the kinesthetic feedback and virtual hand movements. Two separate measures of agency are employed: established psychophysical questionnaires (to capture the explicit experience of agency) and a time interval estimate task to capture the implicit sense of agency (intentional binding). Results of this protocol (questionnaire scores and time interval estimates) can be analyzed to quantify the extent of agency formation.

Here we present a protocol which characterizes the sense of agency developed over the control of sensate virtual or robotic prosthetic hands. Psychophysical questionnaires are employed to capture the explicit experience of agency, and time interval estimates (intentional binding) are employed to implicitly measure the sense of agency.

神经机台面假体作用的代理感特征

This work describes a methodological framework that can be used to explicitly and implicitly characterize the sense of agency developed over the ...

Applying Incongruent Visual-Tactile Stimuli during Object Transfer with Vibro-Tactile Feedback

The application of incongruent sensory signals that involves disrupted tactile feedback is rarely explored, specifically with the presence of vibrotactile feedback (VTF). This protocol aims to test the effect of VTF on the response to incongruent visual-tactile stimuli. The tactile feedback is acquired by grasping a block and moving it across a partition. The visual feedback is a real-time virtual presentation of the moving block, acquired using a motion capture system. The congruent feedback is the reliable presentation of the movement of the block, so that the subject feels that the block is grasped and see it move along with the path of the hand. The incongruent feedback appears as the movement of the block diverts from the actual movement path, so that it seems to drop from the hand when it is actually still held by the subject, thereby contradicting the tactile feedback. Twenty subjects (age 30.2 &#177; 16.3) repeated 16 block transfers, while their hand was hidden. These were repeated with VTF and without VTF (total of 32 block transfers). Incongruent stimuli were presented randomly twice within the 16 repetitions in each condition (with and without VTF). Each subject was asked to rate the difficulty level of performing the task with and without the VTF. There were no statistically significant differences in the length of the hand paths and durations between transfers recorded with congruent and incongruent visual-tactile signals &#8211; with and without the VTF. The perceived difficulty level of performing the task with the VTF significantly correlated with the normalized path length of the block with VTF (r = 0.675, p = 0.002). This setup is used to quantify the additive or reductive value of VTF during motor function that involves incongruent visual-tactile stimuli. Possible applications are prosthetics design, smart sport-wear, or any other garments that incorporate VTF.

We present a protocol to apply incongruent visual-tactile stimuli during an object transfer task. Specifically, during block transfers, performed while the hand is hidden, a virtual presentation of the block shows random occurrences of false block drops. The protocol also describes adding vibrotactile feedback while performing the motor task.

在振动触觉反馈的对象传递过程中应用不一致的视觉触觉刺激

The application of incongruent sensory signals that involves disrupted tactile feedback is rarely explored, specifically with the presence of vibrotactile ...

Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface

The fields that develop methods for sensory substitution and sensory augmentation have aimed to control external goals using signals from the central nervous systems (CNS). Less frequent however, are protocols that update external signals self-generated by interactive bodies in motion. There is a paucity of methods that combine the body-heart-brain biorhythms of one moving agent to steer those of another moving agent during dyadic exchange. Part of the challenge to accomplish such a feat has been the complexity of the setup using multimodal bio-signals with different physical units, disparate time scales and variable sampling frequencies.
In recent years, the advent of wearable bio-sensors that can non-invasively harness multiple signals in tandem, has opened the possibility to re-parameterize and update the peripheral signals of interacting dyads, in addition to improving brain- and/or body-machine interfaces. Here we present a co-adaptive interface that updates efferent somatic-motor output (including kinematics and heart rate) using biosensors; parameterizes the stochastic bio-signals, sonifies this output, and feeds it back in re-parameterized form as visuo/audio-kinesthetic reafferent input. We illustrate the methods using two types of interactions, one involving two humans and another involving a human and its avatar interacting in near real time. We discuss the new methods in the context of possible new ways to measure the influences of external input on internal somatic-sensory-motor control.

We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change.

使用闭环接口实时代理控制重新参数化的外围信号

The fields that develop methods for sensory substitution and sensory augmentation have aimed to control external goals using signals from the central ...

A Method for Evaluating Timeliness and Accuracy of Volitional Motor Responses to Vibrotactile Stimuli

Artificial sensory feedback (ASF) systems can be used to compensate for lost proprioception in individuals with lower-limb impairments. Effective design of these ASF systems requires an in-depth understanding of how the parameters of specific feedback mechanism affect user perception and reaction to stimuli. This article presents a method for applying vibrotactile stimuli to human participants and measuring their response. Rotating mass vibratory motors are placed at pre-defined locations on the participant's thigh, and controlled through custom hardware and software. The speed and accuracy of participants' volitional responses to vibrotactile stimuli are measured for researcher-specified combinations of motor placement and vibration frequency. While the protocol described here uses push-buttons to collect a simple binary response to the vibrotactile stimuli, the technique can be extended to other response mechanisms using inertial measurement units or pressure sensors to measure joint angle and weight bearing ratios, respectively. Similarly, the application of vibrotactile stimuli can be explored for body segments other than the thigh.

This article describes a technique for applying vibrotactile stimuli to the thigh of a human participant, and measuring the accuracy and reaction time of the participant&#39;s volitional response for various combinations of stimulation location and frequency.

一种意志的运动反应的及时性和准确性，以振动触觉刺激评价方法

Artificial sensory feedback (ASF) systems can be used to compensate for lost proprioception in individuals with lower-limb impairments.  Effective design ...

Experimental Methods to Study Human Postural Control

Many components of the nervous and musculoskeletal systems act in concert to achieve the stable, upright human posture. Controlled experiments accompanied by appropriate mathematical methods are needed to understand the role of the different sub-systems involved in human postural control. This article describes a protocol for performing perturbed standing experiments, acquiring experimental data, and carrying out the subsequent mathematical analysis, with the aim of understanding the role of musculoskeletal system and central control in human upright posture. The results generated by these methods are important, because they provide insight into the healthy balance control, form the basis for understanding the etiology of impaired balance in patients and the elderly, and aid in the design of interventions to improve postural control and stability. These methods can be used to study the role of somatosensory system, intrinsic stiffness of ankle joint, and visual system in postural control, and may also be extended to investigate the role of vestibular system. The methods are to be used in the case of an ankle strategy, where the body moves primarily about the ankle joint and is considered a single-link inverted pendulum.

This article presents an experimental/analytic framework to study human postural control. The protocol provides step-by-step procedures for performing standing experiments, measuring body kinematics and kinetics signals, and analyzing the results to provide insight into the mechanisms underlying human postural control.

研究人体姿势控制的实验方法

Many components of the nervous and musculoskeletal systems act in concert to achieve the stable, upright human posture. Controlled experiments accompanied ...

WheelCon: A Wheel Control-Based Gaming Platform for Studying Human Sensorimotor Control

Feedback control theory has been extensively implemented to theoretically model human sensorimotor control. However, experimental platforms capable of manipulating important components of multiple feedback loops lack development. This paper describes WheelCon, an open-source platform aimed at resolving such insufficiencies. Using only a computer, a standard display, and inexpensive gaming steering wheel equipped with a force feedback motor, WheelCon safely simulates the canonical sensorimotor task of riding a mountain bike down a steep, twisting, bumpy trail. The platform provides flexibility, as will be demonstrated in the demos provided, so that researchers may manipulate the disturbances, delay, and quantization (data rate) in the layered feedback loops, including a high-level advanced plan layer and a low-level delayed reflex layer. In this paper, we illustrate WheelCon&#39;s graphical user interface (GUI), the input and output of existing demos, and how to design new games. In addition, we present the basic feedback model and the experimental results from the demo games, which align well with the model&#39;s prediction. The WheelCon platform can be downloaded at https://github.com/Doyle-Lab/WheelCon. In short, the platform is featured to be cheap, simple to use, and flexible to program for effective sensorimotor neuroscience research and control engineering education.

WheelCon is a novel, free and open-source platform to design video games that noninvasively simulates mountain biking down a steep, twisting, bumpy trail. It contains components presenting in human sensorimotor control (delay, quantization, noise, disturbance, and multiple feedback loops) and allows researchers to study the layered architecture in sensorimotor control.

轮式康:一个基于车轮控制的游戏平台，用于研究人类传感器运动控制

Feedback control theory has been extensively implemented to theoretically model human sensorimotor control. However, experimental platforms capable of ...

神经科学

Effects of feedback

Feedback in control systems plays a critical role in shaping various operational parameters, extending beyond simple error reduction to influence stability, bandwidth, gain, impedance, and sensitivity. Understanding these effects requires examining a basic feedback system characterized by defined input, output, error, and feedback signals.
Feedback significantly modifies the gain of a control system. The gain of a system without feedback is altered by a factor of one plus GH, where G represents the open-loop gain and H is the feedback factor. This alteration means feedback can amplify or attenuate the gain depending on the frequency range, thus influencing the overall system performance.
Stability is another crucial aspect affected by feedback. Stability refers to the system&#39;s ability to accurately follow an input command and maintain a controllable output. An unstable system cannot reliably track input commands, resulting in erratic and uncontrollable outputs. Feedback can impact stability in two opposing ways: it can either destabilize an initially stable system or stabilize an unstable one. If the product GH equals negative one, the system becomes unstable, as any finite input results in an infinite output. Conversely, incorporating a negative feedback loop can stabilize an otherwise unstable system by adjusting the feedback gain appropriately.
In addition to gain and stability, feedback also affects a system&#39;s response to extraneous signals and noise. In the presence of disturbances, feedback helps minimize the impact of these unwanted signals. If the factor in the feedback loop&#39;s denominator is greater than unity and the system remains stable, the noise component is effectively reduced. This reduction is crucial in maintaining the integrity of the desired signal and ensuring the system&#39;s robustness against external interferences.
Overall, feedback mechanisms are indispensable in refining the performance of control systems. By carefully designing and implementing feedback loops, engineers can enhance stability, control gain, minimize noise, and improve the system&#39;s responsiveness and accuracy. The strategic use of feedback thus plays a pivotal role in advancing the efficacy and reliability of modern control systems across various applications.

反馈的影响

Feedback in control systems extends beyond error reduction, impacting aspects like stability, bandwidth, gain, impedance, and sensitivity.
The significant ...