The use of vibrotactile feedback is of growing interest in the field of prosthetics, but few devices fully integrate this technology in the prosthesis to transmit high-frequency contact information (such as surface roughness and first contact) arising from the interaction of the prosthetic device with external items. This study describes a wearable vibrotactile system for high-frequency tactile information embedded in the prosthetic socket. The device consists of two compact planar vibrotactile actuators in direct contact with the user's skin to transmit tactile cues. These stimuli are directly related to the acceleration profiles recorded with two IMUS placed on the distal phalanx of a soft under-actuated robotic prosthesis (SoftHand Pro). We characterized the system from a psychophysical point of view with fifteen able-bodied participants by computing participants' Just Noticeable Difference (JND) related to the discrimination of vibrotactile cues delivered on the index finger, which are associated with the exploration of different sandpapers. Moreover, we performed a pilot experiment with one SoftHand Pro prosthesis user by designing a task, i.e. Active Texture Identification, to investigate if our feedback could enhance users' roughness discrimination. Results indicate that the device can effectively convey contact and texture cues, which users can readily detect and distinguish.

翻译：摘要：振动触觉反馈在假肢领域的应用日益受到关注，但很少有设备能将该技术完全集成于假肢中以传递由假肢装置与外部物体交互产生的高频接触信息（如表面粗糙度和初始接触）。本研究描述了一种嵌入假肢接受腔的可穿戴振动触觉系统，用于传输高频触觉信息。该装置包含两个紧凑型平面振动触觉执行器，直接与用户皮肤接触以传递触觉信号。这些刺激与安装在软体欠驱动假肢（SoftHand Pro）远端指骨上的两个惯性测量单元记录的加速度曲线直接相关。我们从心理物理学角度对系统进行表征，通过计算15名健全参与者在区分传递至食指的振动触觉信号时的最小可觉差，这些信号与探索不同砂纸表面相关。此外，我们与一名SoftHand Pro假肢使用者开展先导实验，通过设计“主动纹理识别”任务探究反馈能否提升用户粗糙度辨别能力。结果表明，该装置能有效传递用户可即时检测并区分的接触与纹理信号。