发表机构
University of Michigan（密歇根大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究设计并验证了一款2.6kg、24.5cm高的轻量化低轮廓QDD动力膝关节假肢，其性能达到商用水平，证实了QDD假肢的临床可行性。
AI 中文摘要
与传统被动膝关节不同，全动力膝关节假肢可执行受控正功，减少使用者在高能耗活动中代偿行为的需求。虽然准直接驱动（QDD）执行器相比传统高减速比执行器具备更优异的扭矩控制、背驱动性及声学噪声特性，但此前的QDD原型机因过重、体积过大而难以商业化转化。本研究设计并验证了一款新型轻量化QDD膝关节假肢，其重量为2.6kg，轮廓低矮，尖端至尖端的结构高度为24.5cm。通过优化18:1的两级传动机构，并结合热分析与结构有限元分析，我们显著降低了装置质量，同时实现了145Nm的峰值扭矩。通过台架测试，我们验证了该装置的高输出扭矩、低背驱动扭矩（1Nm）以及精准的位置与扭矩控制能力。我们还对3名不同K级水平的大腿截肢受试者进行了平地行走和坐站转移测试，结果显示该假肢具备仿生运动学特性，且膝关节峰值伸展扭矩与健全受试者的参考值相差在一个标准差范围内。该装置在重量、结构高度、峰值扭矩及声学噪声等方面达到或优于主流商用动力膝关节的指标，证明了新兴QDD假肢的临床可行性，有望为使用者带来更优的动态性能。
英文摘要
Fully-powered knee prostheses, unlike traditional passive knees, can perform controlled positive work, reducing the need for compensatory behaviors by users during energy-intensive activities. While quasi-direct drive (QDD) actuators provide superior torque control, backdrivability, and acoustic noise properties compared to traditional highly-geared actuators, prior QDD prototypes have been too heavy and bulky for commercial translation. In this work, we present the design and validation of a new lightweight (2.6 kg) and low-profile (24.5 cm tip-to-tip build height) QDD knee prosthesis. By optimizing an 18 to 1 two-stage transmission alongside thermal and structural finite-element analyses, we significantly reduce device mass while enabling a peak torque of 145 Nm. Through benchtop tests, we validate the device's high output torque, low backdrive torque (1 Nm), and its precision position and torque control capabilities. We also demonstrate biomimetic kinematics and peak knee extension torques (within one standard deviation of able-bodied references) during both level-ground walking and sit-stand transitions performed by three participants with transfemoral amputation and varying K-levels. By meeting or improving upon the mass, build height, peak torque, and acoustic noise of a leading commercial powered knee, this work establishes the clinical viability of emerging QDD prostheses that promise improved dynamic performance for their users.
Comments11 pages, 8 figures, Under Review
