Multichannel Electrotactile Feedback With Spatial and Mixed Coding for Closed-Loop Control of Grasping Force in Hand Prostheses
Multichannel Electrotactile Feedback With Spatial and Mixed Coding for Closed-Loop Control of Grasping Force in Hand Prostheses
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DOI：
10.1109/tnsre.2016.2550864
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发表时间：
2017-03-01
影响因子：
4.9
通讯作者：
Farina, Dario
中科院分区：
文献类型：
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作者：
Dosen, Strahinja;Markovic, Marko;Farina, Dario
为肌电义肢使用者提供体感反馈是一个重要的目标，因为它可以提高辅助系统的实用性，并促进其实施。通常，抓握力被选为反馈变量，并通过一个或多个单独的单通道刺激单元（如电极、振动电机）进行交流。在本研究中，提出了一种集成的、紧凑的、多通道的解决方案，包括阵列电极和可编程刺激器。两种编码方案（15级），空间和混合（空间和频率）调制，在健全的受试者，心理测量和力控制常规抓取和力跟踪使用真实和模拟假体。结果表明，混合编码和空间编码虽然在心理测试中有很大不同，但在两种力控制任务中产生了相似的表现。在常规抓握中，理想的视觉反馈并不优于触觉反馈。为了解释观察到的结果，提出了一个概念模型，强调性能取决于多个因素，包括反馈的不确定性，任务的性质和前馈控制的可靠性。研究结果、具体结论和一般模型对利用触觉反馈的闭环肌电义肢的设计具有一定的指导意义。
Providing somatosensory feedback to the user of a myoelectric prosthesis is an important goal since it can improve the utility as well as facilitate the embodiment of the assistive system. Most often, the grasping force was selected as the feedback variable and communicated through one or more individual single channel stimulation units (e.g., electrodes, vibration motors). In the present study, an integrated, compact, multichannel solution comprising an array electrode and a programmable stimulator was presented. Two coding schemes (15 levels), spatial and mixed (spatial and frequency) modulation, were tested in able-bodied subjects, psychometrically and in force control with routine grasping and force tracking using real and simulated prosthesis. The results demonstrated thatmixed and spatial coding, although substantially different in psychometric tests, resulted in a similar performance during both force control tasks. Furthermore, the ideal, visual feedback was not better than the tactile feedback in routine grasping. To explain the observed results, a conceptual model was proposed emphasizing that the performance depends on multiple factors, including feedback uncertainty, nature of the task and the reliability of the feedforward control. The study outcomes, specific conclusions and the general model, are relevant for the design of closed-loopmyoelectric prostheses utilizing tactile feedback.