NRI: Towards Restoring Natural Sensation of Hand Amputees via Wearable Surface Grid Electrodes

手部截肢会严重限制生活质量，例如，使其无法感知和操纵物体，或表达手势。到目前为止，已经开发出了许多机械假肢，其中一些假肢的灵巧性接近人手，但限制人们接受这些设备的一个关键因素是缺乏对用户的自然可靠的感官反馈；替代非自然刺激，如皮肤振动、视觉或音频提示，并不能真正解决问题。PI在这项研究中的目标是探索使用非侵入性网格电极电刺激周围感觉神经，使它们将自然的（高分辨率）触觉传递到中枢神经系统。该项目的成功将彻底改变人类与机器人假肢交流的方式，并改变闭环假肢控制的研究，将截肢者的触觉反馈从侵入性植入技术转移到非侵入性表面探测技术。新技术的非侵入性表现出具有高功能效率和用户接受度的快速临床转化的潜力。因此，这项研究将极大地改善手部截肢者的生活质量。此外，这项工作将被整合到PI所在机构的研究生和本科生教育中，面向K-12学生（尤其是代表性不足的STEM学生）的外展项目将使他们接触到这一创新科学。这个极具创意的项目采用了一种与现有的感官恢复/增强技术完全不同的方法，并得到了团队初步研究的支持。首先，研究人员将设计一种新颖的、非侵入性的纳米线传感器阵列，它将提供对缺失的手的自然感觉。薄膜电极网格将具有自粘性和高度可拉伸性。多功能电极不仅可以提供有针对性的神经刺激，还可以记录施加在假手上的压力，因此它们既可以获得丰富的触觉信息，也可以准确无误地将这些信息传递给用户，同时产生最小的干扰，如皮肤不适、设备增加的重量和控制信号干扰。其次，该团队将通过开发一种动态刺激方案来创造一种提供感官恢复的新方法，该方案可以对手指和手掌的空间不同的触觉进行编码。这将通过选择性地招募支配手部不同区域的各种传入纤维来实现。研究人员认为，基于手部区域映射的高空间分辨率，触觉反馈可以首次使用户通过“使用”他们失去的手来真正感知环境，从而将化身感推向一个新的水平。最后，通过量化感觉运动整合过程对截肢者灵巧假手闭环控制的影响，将获得新的知识。

Hand amputation can severely limit the quality of life, for example by making it impossible to sense and manipulate objects, or to express gestures. Many robotic prosthetic hands have been developed to date, some of which have dexterity approaching that of a human hand, but a key factor limiting acceptance of these devices is the lack of natural and reliable sensory feedback to the user; the substitution of un-natural stimuli such as skin vibration, visual or audio cues doesn't really cut it. The PI's goal in this research is to explore the use of non-invasive grid electrodes for electrically stimulating the peripheral sensory nerves so they transmit natural (high resolution) haptic sensations to the central nervous system. Success of this project will revolutionize the way in which human beings communicate with robotic prostheses and transform research in close-loop prosthesis control, shifting amputee haptic sensation feedback from invasive implant techniques to non-invasive surface probing techniques. The non-invasive nature of the new technology presents the potential for rapid clinical translations with high functional efficiency and user acceptance. Thus, the research will lead to dramatic improvements in hand amputees' quality of life. In addition, the work will be integrated into graduate and undergraduate student education at the PI's institution, and outreach programs for K-12 students (especially underrepresented STEM students) will expose them to this innovative science.This highly creative project adopts an approach that is completely different from the existing techniques for providing sensory restoration/augmentation, and which is supported by the team's preliminary studies. First, the investigators will design a novel, non-invasive nanowire sensor array that will provide natural sensation of the missing hand. The thin-film electrode grid will be self-adhesive and highly stretchable. The multifunctional electrodes will be able not only to provide targeted nerve stimulation but also to record pressures applied on the prosthetic hand, so they can both obtain a rich set of haptic information and also deliver this information to the user accurately and precisely, while inducing minimal interference such as skin discomfort, added weight due to the device, and control signal interference. Second, the team will create a new way of affording sensory restoration by developing a dynamic stimulation scheme that encodes spatially distinct haptic sensations in the digits and palm. This will be achieved by selectively recruiting the various afferent fibers innervating different regions of the hand. The investigators believe that with high spatial resolution based on hand region mapping, the haptic feedback could for the first time enable users to truly perceive the environment by "using" their lost hand, and thereby push the sense of embodiment to a new level. Lastly, new knowledge will be obtained by quantifying the effect of the sensorimotor integration process on closed-loop control of a dexterous prosthetic hand in amputees.