BACKGROUND Vibrotactile stimulation is a promising venue in the field of prosthetics to retrain sensory feedback deficits following amputation. Discrimination is well established at the forearm level but not at the upper arm level. Moreover, the effects of combining vibration characteristics such as duration and intensity has never been investigated. METHOD We conducted experiments on spatial discrimination (experiment 1) and tactile intensity perception (experiment 2), using 9 combinations of 3 intensities and 3 durations of vibror stimulations device. Those combinations were tested under 4 arrangements with an array of 6 vibrors. In both experiments, linear orientation aligned with the upper arm longitudinal axis were compared to circular orientation on the upper arm circumference. For both orientations, vibrors were placed either with 3cm space between the center of 2 vibrors or proportionally to the length or the circumference of the subject upper arm. Eleven heathy subjects underwent the 2 experiments and 7 amputees (humeral level) participated in the spatial discrimination task with the best arrangement found. RESULTS Experiment 1 revealed that circular arrangements elicited better scores than the linear ones. Arrangements with vibrors spaced proportionally elicited better scores (up to 75% correct) than those with 3 cm spacing. Experiment 2, showed that the perceived intensity of the vibration increases with the intensity of the vibrors' activation, but also with their duration of activation. The 7 patients obtained high scores (up to 91.67% correct) with the circular proportional (CP) arrangement. DISCUSSION These results highlight that discrete and short vibrations can be well discriminated by healthy subjects and people with an upper limb amputation. These new characteristics of vibrations have great potential for future sensory substitution application in closed-loop prosthetic control.

中文翻译：

---

振动特征和振动器排列对健康受试者和上肢截肢者上臂的触觉的影响。

背景技术触觉刺激是假肢领域中在截肢后重新训练感觉反馈缺陷的有前途的场所。在前臂水平已经建立了很好的歧视，但在上臂水平却没有。而且，从未研究结合诸如持续时间和强度的振动特性的效果。方法我们使用3种强度和3种持续时间的振动刺激装置的9种组合，进行了空间辨别力（实验1）和触觉强度感知（实验2）的实验。在具有6个振动器阵列的4种布置下测试了这些组合。在两个实验中，将与上臂纵轴对齐的线性方向与在上臂圆周上的圆形方向进行了比较。对于两个方向，将振动器放置在两个振动器中心之间的距离为3cm的位置，或者与对象上臂的长度或周长成比例地放置。11名健康受试者进行了2次实验，有7名截肢者（肱骨水平）以最佳布置参加了空间辨别任务。结果实验1表明，与线性排列相比，圆形排列的得分更高。与按3厘米间距的振动器相比，按比例隔开振动器的布置产生的得分更高（正确率高达75％）。实验2表明，振动的感知强度随振动器激活强度的增加而增加，也随其激活持续时间的增加而增加。7名患者采用圆形比例（CP）布置获得了高分（正确率高达91.67％）。讨论这些结果表明，健康受试者和上肢截肢患者可以很好地区分离散振动和短暂振动。这些新的振动特性为闭环假体控制中未来的感官替代应用提供了巨大的潜力。