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

项目摘要 人类的手腕，它的位置手完成许多基本的日常生活任务，提供了三个 自由度（DOF）：旋转、屈曲/伸展和尺/桡偏。电流驱动假肢 腕部仅提供腕部旋转;没有可用的动力装置提供腕部伸展/弯曲，这可能 降低了经桡动脉截肢患者的功能能力。我们已经开发了一个强大的2自由度 提供独立控制的旋转和伸展/屈曲的手腕;我们建议进行第1阶段 临床试验，以确定该腕部是否提供比1-DOF腕部更好的功能性能（旋转 仅）。此外，我们还开发了一种基于模式识别（PR）的控制系统，现已商业化 可用，将用于控制本试验中的器械。肌电信号的PR 残肢提供了手臂自由度的无缝顺序控制，使控制更容易，更直观， 传统的肌电控制系统需要使用者将假体切换到不同的模式， 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。 我们开发了一种新的PR算法，基于一种称为概率的新型控制方法， 加权回归，在初步研究中，已经证明了多自由度假体的鲁棒控制。 因此，我们还将评估与序贯PR控制相比，同时PR控制的功能益处。 我们将招募最多20名中等长度、单侧经桡动脉截肢的患者参加试验， 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 包括单自由度腕部和单自由度或多自由度终端装置。对于每个测试条件，我们将 培训参与者使用顺序PR控制，并使用全面的 结果测量工具箱，根据修复学会的建议编制， 矫正术和我们之前的研究经验。参与者将把假肢带回家， 六周的日常任务，允许广泛的实践，以优化他们对设备的功能控制。在 家庭试验结束后，参与者将进行相同的结果测量以评估功能。我们会重复 该序列用于目标2，其中参与者将评估除2-DOF腕部之外的相同的两个假体。 最后，对于目标3，我们将遵循相同的方案，比较连续和同时PR控制的一个 具有1-DOF手和2-DOF腕的假肢。我们预计，两个自由度的手腕和同时 PR控制系统将分别提供比1-DOF腕部和顺序控制更好的功能。这 研究将提供2-DOF腕关节和同时PR控制的益处的定量评估， 这对于这些技术的商业化和进一步发展是必要的， 选择，和功能能力，为经桡截肢的个人。

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.