CAREER: Biologically-Inspired Actuation and Control of Robotic Above-Knee Prostheses

概述：本CAREER提案的研究解决了新兴动力膝盖以上（AK）假肢领域的两个基本问题——驱动和控制——采用创新的生物启发机器人方法。目标是为动力AK假肢提供足够的功率输出，长时间的操作和可靠的意志控制能力，使其能够在截肢者的日常生活中使用。通过解决这些基本问题，该项目将为PI的长期研究目标奠定坚实的基础，即创造具有与生物肢体相当的功能和外观的动力假肢装置，使截肢患者能够像健康人一样享受生活。这项建议的教育活动旨在与一系列以“用机器人帮助残障人士！”为主题的活动产生协同效应。这些活动将为PI的长期教育目标奠定基础，该目标是创建一个综合的机器人教育计划，该计划将多个层次（研究生，本科生和K-12）的教育和研究结合起来，重点是招募，保留和指导残疾学生。智力优势：尽管最近的技术进步，大多数最先进的AK假肢仍然没有动力。生物力学研究表明，这些装置无法恢复正常的运动功能。本项目的研究旨在通过一种新型的化学流体袖肌肉驱动系统将动力AK假肢变为现实，该系统相对于传统的电池-直流电机系统具有显著的优势。这个新系统中的致动器，袖肌致动器，与直流电动机相比提供了优越的功率密度（至少高10倍）。它还可以使用创新的设计理念-将关节执行器与承重结构集成在一起-因此可以潜在地生成适合日常使用的高度紧凑的AK假体。新系统还采用了一种新的能量储存介质，即单推进剂，为AK假体提供充足的能量供应。作为一类独特的液体燃料，单体推进剂通过催化反应（而不是燃烧）释放能量。安全反应产物氧和水蒸气可直接作为高压工作流体驱动袖肌作动器。因此，单推进剂可以形成高度紧凑的气动供应的基础，以支持动力AK假体所需的长时间操作。新的驱动系统将与一种新的假肢控制方法相辅相成，即容错肌电图直接控制。这种新方法通过肌电图（EMG）提供的神经接口实现了对假肢的意志（即根据意图）控制。此外，为了解决肌电图接口的可靠性问题，将创建一个容错控制结构，在肌电图故障时重新配置控制器。因此，这种新颖的方法有望允许用户根据他或她的意图控制假体，同时避免控制器完全失效的危险，例如跌倒和由此造成的伤害。更广泛的影响：目前，美国有超过40万AK截肢者，预计到2050年这一数字将翻一番。这项提议的研究有可能通过显著改善这些截肢者的行动能力和生活质量来造福社会。此外，根据PI正在进行的教育工作，本项目将通过将研究与教育相结合来开展新的教育活动。这些活动包括：(1)为招收、保留和指导残疾学生建立一个全面的计划；(2)促进工程和修复矫形学的研究生教育，努力弥合生物医学工程研究与临床实践之间的差距；(3)以科学博物馆机械臂展为目标，开展多年期科研项目，促进本科生科研工作；(4)与全球第一所获得steam认证的小学合作，深入K-12教育体系，开展以机器人为主题的科学与工程活动。

Shen1351520Overview: The research in this CAREER proposal addresses two fundamental issues in the emerging powered above-knee (AK) prosthetics area -- Actuation and Control -- with innovative biologically-inspired robotic approaches. The objective is to provide sufficient power output, long duration of operation, and reliable volitional control capability for powered AK prostheses to enable their use in the amputee users- daily life. By addressing these fundamental issues, this project will lay a solid foundation for the PI's long-term research goal of creating powered prosthetic devices with comparable functionality and appearance as biological limbs, so that amputee patients can enjoy life like healthy persons. The educational activities in this proposal aim to generate a synergistic impact with a series of activities under a common theme of "Using Robotics to Help Persons with Disabilities!" These activities will build a basis for the PI's long-term education goal of creating a comprehensive robotics education program that integrates education and research on multiple levels (graduate, undergraduate, and K-12), with the emphasis on recruiting, retaining, and mentoring students with disabilities.Intellectual Merit: Despite recent technological advances, the majority of state-of-the-art AK prostheses are still unpowered. Biomechanical studies show that these devices are unable to restore the normal locomotive functions. The research in this project aims at bringing powered AK prostheses to reality with a novel chemo-fluidic sleeve muscle actuation system, which provides a significant advantage relative to the traditional battery-DC motor system. The actuator in this new system, sleeve muscle actuator, provides a superior power density compared with DC motor (at least 10 times higher). It also enables the use of an innovative design philosophy - integrating joint actuator with load bearing structure -- and thus can potentially generate a highly compact AK prosthesis suitable for daily use. The new system also incorporates a new energy-storing medium, namely monopropellant, to provide ample energy supply for the AK prosthesis. As a unique class of liquid fuel, monopropellant releases energy through catalytic reaction (instead of combustion). The safe reaction products, oxygen and water steam, can be used directly as the high-pressure working fluid to drive the sleeve muscle actuator. As such, monopropellant can form the basis of a highly compact pneumatic supply to support the desired long duration of operation for powered AK prostheses. The new actuation system will be complemented with a novel prosthesis control approach, namely fault-tolerant EMG direct control. This new approach enables volitional (i.e., according-to-the-intent) control of the prosthesis through the neural interface provided by electromyography (EMG). Furthermore, to address the reliability issue of EMG interface, a fault-tolerant control structure will be created, which reconfigures the controller in the event of EMG failure. As such, this novel approach is anticipated to allow the user to control the prosthesis according to his or her intention while avoiding the hazards from a complete controller failure, such as falling and the resulting injuries.Broader Impacts: Currently, there are more than 400,000 AK amputees in the U.S., and this number is expected to double by 2050. The proposed research has the potential to benefit society by significantly improving these amputees' mobility and quality of life. Furthermore, based on the PI's ongoing educational efforts, new education activities will be conducted in this project by integrating research into education. These activities include: (1) Establish a comprehensive plan for the recruitment, retention, and mentoring of students with disabilities; (2) Contribute to graduate education in both engineering and prosthetics & orthotics with the efforts towards bridging the gap between biomedical engineering research and clinical practice; (3) Promote undergraduate research with a multi-year research project aiming at developing a robotic arm exhibit for a science museum; (4) Outreach into K-12 education system to promote science and engineering with robotics-themed activities, collaborating with the first STEAM-accredited elementary school in the world.