Lightweight Powered Prosthesis for above-knee amputees

项目摘要 在40万膝上截肢的美国人中，大多数人不能以可变的速度行走， 用规定的假体安全地克服环境障碍[4]。这种有限的功能活动性 严重影响他们的独立性，并导致继发性健康问题，如背痛，骨关节炎， 抑郁症[5]。动力假体有可能通过提供能量来解决这些问题， 爬上坡道或楼梯或从坐姿站起来，并通过改善行走稳定性和脚 间隙然而，现有的动力装置的设计，以适应需要的年轻，强壮， 绝大多数人由于创伤而失去肢体， 使用被动假肢。 本提案的目的是确定提高活动水平所需的关键假肢技术 膝上截肢者从有限（K2）到社区（K3）的步行者。我们的中心假设是， 轻型动力假肢可以促进向变速假肢的过渡， 环境障碍（K3级），适用于目前功能处于K2上端的截肢患者 水平我们之前的工作已经生产出了第一个动力膝关节和踝关节假体[11]-[15]，将联合收割机 无源器械的重量（~5.5 lbs）与动力假体的发电能力（~400 W） [16]-[18]。此外，我们还开发了一个创新的控制框架， 动力假肢关节的运动与残肢的运动，同时调节能量 基于步行速度的注射[19]。这些新的轻质假肢技术已经初步 在身体健全的受试者和年轻创伤性膝上截肢者（K3-K4级）水平行走中进行了验证 [20]和倾斜的地面在可变的速度，爬上爬下楼梯[12]。此外，我们的初步 三个K2以上的膝盖科目的实验证明了所提出的方法的可行性。 提出这项研究的理由是，了解轻型机器人技术如何有助于 功能性活动将使创新的设计和处方的假肢，以解决特定的需求， 为血管障碍和老年截肢者提供更好的医疗保健、活动能力和生活质量。 这一贡献是重要的，因为轻质动力假体具有延长寿命的潜力 并大大提高多达100万下肢截肢者的生活质量，预计这些人将 到2050年翻一番我们的方法是创新的，因为它利用了一种新的假肢技术， 现有被动假体的重量轻，而不牺牲功率和扭矩产生能力， 第一次解决了血管障碍患者的特殊需求。这项工作预计将累计提供 全面了解工程，生物力学和临床因素，有助于 截肢患者功能性步行能力从受限到社区步行能力提高。

Project summary Most of the 400,000 Americans living with an above-knee amputation [3] cannot walk at variable speeds and safely negotiate environmental barriers with their prescribed prostheses [4]. This limited functional mobility severely affects their independence and results in secondary health problems, such as back pain, osteoarthritis, and depression [5]. Powered prostheses have the potential to address these problems by providing energy for climbing on ramps or stairs or standing up from a seated position, and by improving walking stability and foot clearance. However, available powered devices are designed to accommodate the needs of young, strong people, who overwhelmingly lose their limb due to trauma and can already achieve full community ambulation with available passive prostheses. The objective of this proposal is to identify key prosthesis technologies required to improve the mobility level of above-knee amputees form limited (K2) to community (K3) ambulators. Our central hypothesis is that a lightweight powered prosthesis can facilitate a transition into variable-speed ambulation and the negotiation of environmental barriers (K3 level) for those amputee patients who currently function at the upper end of the K2 level. Our previous work has produced the first powered knee and ankle prosthesis [11]–[15] to combine the lightness of a passive device (~5.5 lbs) with the power generation capability of a powered prosthesis (~400 W) [16]–[18]. In addition, we have developed an innovative control framework that automatically synchronizes the movement of the powered prosthesis joints with the movement of the residual leg, while modulating energy injection based on walking speed [19]. These novel lightweight prosthesis technologies have been preliminary validated with able-bodied subjects and young traumatic above-knee amputees (K3-K4 level) walking on level [20] and inclined ground at variable speeds, and climbing up and down stairs [12]. Moreover, our preliminary experiments with three K2 above-knee subjects demonstrate the feasibility of the proposed approach. The rationale for the proposed research is that understanding how lightweight robotic technologies contribute to functional mobility will enable innovative design and prescription of prostheses that address the specific needs of dysvascular and geriatric amputees, resulting in better healthcare, mobility, and quality of life. This contribution is significant because lightweight powered prostheses have the potential to extend longevity and to dramatically improve quality of life for up to a million lower-limb amputees—a population expected to double by 2050. Our approach is innovative because It leverages on a novel prosthesis technology that matches the lightness of available passive prostheses without sacrificing power and torque generation capability to address the specific needs of dysvascular patients for the first time. Cumulatively, this work is expected to provide a comprehensive understanding of the engineering, biomechanical, and clinical factors that contribute to the improvement of functional gait ability of amputee patients from limited to community ambulators.