Witteveen Heidi J B, Luft Frauke, Rietman Johan S, Veltink Peter H
IEEE Trans Neural Syst Rehabil Eng. 2014 Jan;22(1):53-61. doi: 10.1109/TNSRE.2013.2267394. Epub 2013 Jun 20.
The ability to distinguish object stiffness is a very important aspect in object handling, but completely lacking in current myoelectric prostheses. In human hands both tactile and proprioceptive sensory information are required for stiffness determination. Therefore, it was investigated whether it is possible to distinguish object stiffness with vibrotactile feedback of hand opening and grasping force. Three configurations consisting of an array of coin motors and a single miniature vibrotactile transducer were investigated. Ten healthy subjects and seven subjects with upper limb loss due to amputation or congenital defects performed virtual grasping tasks, in which they controlled hand opening and grasping force. They were asked to determine the stiffness of a grasped virtual object from four options. With hand opening feedback alone or in combination with grasping force feedback, correct stiffness determination was achieved in around 60% of the cases and significantly higher than the 25% achieved without feedback or grasping force feedback alone. Despite the equal performance results, the combination of hand opening and grasping force feedback was preferred by the subjects over the hand opening feedback alone. No differences between feedback configurations and between subjects with upper limb loss and healthy subjects were found.
区分物体硬度的能力是物体操作中非常重要的一个方面，但目前的肌电假肢完全缺乏这种能力。在人类手中，确定硬度需要触觉和本体感觉信息。因此，研究了是否可以通过手张开和抓握力的振动触觉反馈来区分物体硬度。研究了由一系列硬币电机和单个微型振动触觉换能器组成的三种配置。10名健康受试者和7名因截肢或先天性缺陷而上肢缺失的受试者进行了虚拟抓握任务，他们在任务中控制手的张开和抓握力。要求他们从四个选项中确定所抓握虚拟物体的硬度。仅通过手张开反馈或与抓握力反馈相结合，约60%的情况下能正确确定硬度，显著高于无反馈或仅抓握力反馈时达到的25%。尽管性能结果相同，但受试者更喜欢手张开和抓握力反馈的组合，而不是仅手张开反馈。未发现反馈配置之间以及上肢缺失受试者与健康受试者之间存在差异。
