Abstract
Despite advances in upper-limb (UL) prosthetic design, achieving intuitive control of intermediate joints - such as the wrist and elbow - remains challenging, particularly for continuous and velocity-modulated movements. We introduce a novel movement-based control paradigm entitled Compensation Effect Amplification Control (CEAC) that leverages users' trunk flexion and extension as input for controlling prosthetic elbow velocity. Considering that the trunk can be both a functional and compensatory joint when performing upper-limb actions, CEAC amplifies the natural coupling between trunk and prosthesis while introducing a controlled delay that allows users to modulate both the position and velocity of the prosthetic joint. We evaluated CEAC in a generic drawing task performed by twelve able-bodied participants using a supernumerary prosthesis with an active elbow. Additionally a multiple-target-reaching task was performed by a subset of ten participants. Results demonstrate task performances comparable to those obtained with natural arm movements, even when gesture velocity or drawing size were varied, while maintaining ergonomic trunk postures. Analysis revealed that CEAC effectively restores joint coordinated action, distributes movement effort between trunk and elbow, enabling intuitive trajectory control without requiring extreme compensatory movements. Overall, CEAC offers a promising control strategy for intermediate joints of UL prostheses, particularly in tasks requiring continuous and precise coordination.
Abstract (translated)
尽管上肢（UL）假体设计取得了进展，但实现中间关节（如手腕和肘部）的直观控制仍然颇具挑战性，尤其是在连续运动和速度调节方面。我们引入了一种新的基于动作的控制范式——补偿效应放大控制（CEAC），该范式利用用户的躯干屈曲和伸展作为控制假肢肘部速度的输入。考虑到在执行上肢动作时，躯干可以是一个功能关节或代偿关节，CEAC 放大了躯干与假肢之间的自然耦合，并引入了一个可控延迟，使用户能够调节假肢关节的位置和速度。我们使用一个具有活动肘部的超数假肢，让十二名健全参与者在通用绘图任务中评估了 CEAC 的效果；此外，十个参与者的子集还执行了多目标到达任务。 结果表明，即使是在变化手势速度或绘制大小的情况下，CEAC 仍能实现与自然手臂运动相当的任务表现，并且保持了符合人体工程学的躯干姿势。分析显示，CEAC 有效地恢复了关节协调动作，在躯干和肘部之间分配了运动努力，使得用户可以直观地控制轨迹而无需进行极端代偿性动作。 总的来说，CEAC 为 UL 假肢中间关节提供了一种有前景的控制策略，尤其是在需要连续且精确协调的任务中。
URL
https://arxiv.org/abs/2601.05074
