The Functional Importance of Powered Wrist Flexion/Extension and Simultaneous Control for Upper Limb Prostheses

项目摘要 人类的手腕定位手来完成日常生活中的许多基本任务，它提供了三种 自由度(DOF)：旋转、屈曲/伸展和尺骨/桡骨偏斜。现代动力假体 手腕只提供手腕旋转；没有可用的电动设备提供手腕伸展/屈曲，这很可能 降低了经桡骨截肢患者的功能。我们已经开发出一种健壮的两自由度 手腕提供独立控制的旋转和伸展/屈曲；我们建议进行阶段1 临床试验，以确定该手腕是否提供了比1自由度手腕更好的功能表现(旋转 仅限)。此外，我们还开发了一种基于模式识别(PR)的控制系统，目前已投入商业使用 可用，它将在本试验中用于控制设备。肌电(EMG)信号的PR 残肢提供对手臂自由度的无缝顺序控制，使控制比 传统的肌电控制系统需要用户将假体切换到不同的模式以 控制不同的自由度。然而，当前的PR系统不允许同时控制所提供的自由度 一只完好无损的手臂。我们开发了一种新的PR算法，该算法基于一种称为概率的新控制方法 加权回归，在初步研究中，已经展示了对多自由度假体的稳健控制。 因此，我们还将评估与顺序PR控制相比，同时PR控制的功能优势。 我们将招募最多20名中长型、单侧经桡动脉截肢的患者参与试验， 预计至少有14名受试者将完成所有三个目标。对于目标1，我们将为参与者安装假肢 包括1自由度手腕和单自由度或多自由度终端设备。对于每个测试条件，我们将 培训学员使用顺序公关控制，并使用全面的 结果测量工具箱，基于假体学会的建议和 矫形学和我们之前的研究经验。参与者随后将把假体带回家并用于 六个星期的日常任务，允许广泛的练习来优化他们对设备的功能控制。在 在主场试验结束后，参与者将执行相同的结果测量以评估功能。我们会重复一遍 Aim 2的这一序列，参与者将评估相同的两个假体，除了2-DOF手腕。 最后，对于目标3，我们将遵循相同的协议来比较顺序和同时PR控制 使用1自由度的手和2自由度的手腕的假体。我们预计两个自由度的手腕和同时的 PR控制系统将分别提供比单自由度手腕和顺序控制更好的功能。这 这项研究将对两自由度腕关节和同时进行PR控制的好处进行定量评估， 这对于商业化和进一步开发这些技术以改进假肢是必要的 选择，和功能能力，为个人经桡骨截肢。

Project Abstract The human wrist, which positions the hand to accomplish many essential tasks of daily living, provides three degrees of freedom (DOFs): rotation, flexion/extension, and ulnar/radial deviation. Current powered prosthetic wrists provide only wrist rotation; no available powered device provides wrist extension/flexion, which likely reduces the functional ability of individuals with transradial amputations. We have developed a robust 2-DOF wrist that provides independently controlled rotation and extension/flexion; we proposed to conduct a phase 1 clinical trial to determine whether this wrist provides better functional performance than a 1-DOF wrist (rotation only). In addition, we have developed a pattern recognition (PR)-based control system, now commercially available, which will be used to control devices in this trial. PR of electromyographic (EMG) signals from the residual limb provides seamless sequential control of arm DOFs, making control easier and more intuitive than conventional myoelectric control systems that require the user to switch the prosthesis into different modes to control different DOFs. However, current PR systems do not allow the simultaneous control of DOFs provided by an intact arm. We have developed a new PR algorithm, based on a novel control method called probabilistic weighted regression that, in preliminary studies, has demonstrated robust control of a multi-DOF prosthesis. Thus we will also evaluate the functional benefits of simultaneous PR control compared to sequential PR control. We will recruit up to 20 individuals with mid-length, unilateral transradial amputations to participate in the trial, anticipating that at least 14 subjects will complete all three aims. For Aim 1 we will fit participants with a prosthesis comprising a 1-DOF wrist and either a single- or a multi-DOF terminal device. For each test condition, we will train participants to use sequential PR control and perform initial functional testing using a comprehensive toolbox of outcome measures, compiled based on recommendations from the Academy of Prosthetics and Orthotics and our prior research experience. Participants will then take the prosthesis home and use it for everyday tasks for six weeks, allowing extensive practice to optimize their functional control of the device. At the end of the home trial, participants will perform the same outcome measures to assess function. We will repeat this sequence for Aim 2, where participants will evaluate the same two prostheses except with the 2-DOF wrist. Finally, for Aim 3, we will follow the same protocol to compare sequential and simultaneous PR control of a prosthesis with a 1-DOF hand and a 2-DOF wrist. We expect that both the 2-DOF wrist and the simultaneous PR control system will provide improved function over the 1-DOF wrist and sequential control, respectively. This study will provide a quantitative assessment of the benefits of a 2-DOF wrist and of simultaneous PR control, which is necessary for commercialization and further development of these technologies to improve prosthetic options, and functional ability, for individuals with transradial amputations.