An exploration of grip force regulation with a low-impedance myoelectric prosthesis featuring referred haptic feedback.
An exploration of grip force regulation with a low-impedance myoelectric prosthesis featuring referred haptic feedback.
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DOI：
10.1186/s12984-015-0098-1
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发表时间：
2015-11-25
影响因子：
5.1
通讯作者：
Gillespie RB
中科院分区：
文献类型：
--
作者：
Brown JD;Paek A;Syed M;O'Malley MK;Shewokis PA;Contreras-Vidal JL;Davis AJ;Gillespie RB
触觉显示技术非常适合于将本体感受、力和接触线索从假肢终端设备中继回残肢，从而减少对视觉反馈的依赖。然而，截肢者解释这些触觉提示的难易程度可能取决于他们的动态信号行为是否与预期行为相对应-与自然肢体耦合到环境的行为一致。终端设备中的高度齿轮传动的电机沿着相关联的高反向驱动阻抗影响与环境的动态相互作用，从而产生自然肢体不会遇到的效果。在这里，我们探讨把握和升降机性能与backdrivable（低反向驱动阻抗）终端设备下放置成比例的肌电位置控制，功能涉及触觉反馈。我们制造了一个背部驱动的终端设备，截肢者和非截肢者都可以使用，并驱动孔径（或握力，当一个坚硬的物体在其掌握）成比例的肌电信号从前臂的一个单一的肌肉部位。在随机排序的试验中，我们评估了N=10名参与者（7名非截肢者，3名截肢者）在三种反馈条件下（无反馈，振动触觉反馈和关节扭矩反馈）尝试使用终端设备抓握和举起物体的性能，以及两个视觉无法辨别的物体重量。非截肢者和截肢者参与者都根据物体重量缩放他们的握力。我们的研究结果表明，只有轻微的差异，在握力，抓地力/负载力协调，并作为一个功能的感觉反馈条件下，滑，虽然在提离点的较重的物体的握力显着更大的截肢参与者在关节扭矩反馈的存在。对抓握/负载力相位图的检查显示，我们的截肢参与者使用了更大的安全裕度，并且表现出比我们的非截肢参与者更少的协调性。我们的研究结果表明，一个backdrivable终端设备可能持有的优势，通过允许抓地力/负载力协调与自然肢体中观察到的行为相一致的非backdrivable设备。同样，指触觉反馈对抓握和提升性能的不确定影响表明需要进行额外的测试，包括对参与者进行充分的培训。
Haptic display technologies are well suited to relay proprioceptive, force, and contact cues from a prosthetic terminal device back to the residual limb and thereby reduce reliance on visual feedback. The ease with which an amputee interprets these haptic cues, however, likely depends on whether their dynamic signal behavior corresponds to expected behaviors—behaviors consonant with a natural limb coupled to the environment. A highly geared motor in a terminal device along with the associated high back-drive impedance influences dynamic interactions with the environment, creating effects not encountered with a natural limb. Here we explore grasp and lift performance with a backdrivable (low backdrive impedance) terminal device placed under proportional myoelectric position control that features referred haptic feedback. We fabricated a back-drivable terminal device that could be used by amputees and non-amputees alike and drove aperture (or grip force, when a stiff object was in its grasp) in proportion to a myoelectric signal drawn from a single muscle site in the forearm. In randomly ordered trials, we assessed the performance of N=10 participants (7 non-amputee, 3 amputee) attempting to grasp and lift an object using the terminal device under three feedback conditions (no feedback, vibrotactile feedback, and joint torque feedback), and two object weights that were indiscernible by vision. Both non-amputee and amputee participants scaled their grip force according to the object weight. Our results showed only minor differences in grip force, grip/load force coordination, and slip as a function of sensory feedback condition, though the grip force at the point of lift-off for the heavier object was significantly greater for amputee participants in the presence of joint torque feedback. An examination of grip/load force phase plots revealed that our amputee participants used larger safety margins and demonstrated less coordination than our non-amputee participants. Our results suggest that a backdrivable terminal device may hold advantages over non-backdrivable devices by allowing grip/load force coordination consistent with behaviors observed in the natural limb. Likewise, the inconclusive effect of referred haptic feedback on grasp and lift performance suggests the need for additional testing that includes adequate training for participants.