Motor-parietal cortical neuroprosthesis with somatosensory feedback for restoring hand and arm functions in tetraplegic patients.

神经假体是一种系统，它允许严重残疾的人用他或她的思想控制一个体外机器人装置。神经义肢的最新发展在提高瘫痪患者的生活质量和自主性方面具有巨大的潜力。尽管在美国已经开始了一些上肢皮质假肢的临床研究，但神经假肢系统的许多方面仍有待研究。例如，目前还不清楚大脑的哪个区域提供了最好的控制信号。到目前为止，大多数研究都集中在运动皮层及其低级运动命令上。在最近的一项人类研究中，我和我在加州理工学院的同事可以证明，我们从后顶叶皮层（PPC）获得的高级认知信号也可以用来驱动神经假体。该计划打算结合来自两个皮层区域的信号——运动皮层和PPC——以提高性能。此外，通过在体感觉皮层中使用皮层内微刺激，它旨在激发四肢瘫痪患者完全失去的触觉。实施有效的体感反馈也可能提高表现，特别是在精细运动任务中，并有可能大幅提高生活质量。该项目的另一个重要部分将是在过渡到物理机器人肢体之前，使用沉浸式虚拟现实来研究视角、视觉呈现和多种控制场景的影响。虚拟现实为我们提供了以节省和快速的方式尝试多种视角，控制方案和场景的机会。最后，它打算使用混合控制系统，其中计算机辅助与皮质控制信号相结合。这种组合系统对长期信号退化的抵抗力更强，可以为四肢瘫痪患者的日常生活活动提供最佳的帮助。

A neuroprosthesis is a system which allows a severely disabled person to control an extracorporeal robotic device with his or her thoughts. Recent developments in neuroprosthetics have great potential to increase the quality of life and autonomy for paralyzed patients. Although a couple of clinical studies for upper limb cortical prostheses have been started in the USA many aspects of neuroprosthetic systems remain open to research. It is not clear, for example, which areas of the brain are providing the best control signals. Most studies so far focused on the motor cortex and its low-level motor commands. In a recent human study my colleagues and I at Caltech could demonstrate that high-level cognitive signals which we derived from the posterior parietal cortex (PPC) can be used to drive a neuroprosthesis as well. The proposed project intends to combine the signals from both cortical areas - the motor cortex and PPC - to provide improved performance. Furthermore by utilizing intracortical microstimulation in the somatosensory cortex it is intended to elicit tactile sensations which are completely lost to tetraplegics who are paralyzed from the neck down. The implementation of effective somatosensory feedback is also likely to improve performance especially in fine motor tasks and has the potential to substantially improve quality of life. Another essential part of the project will be to use immersive virtual reality to study the influence of perspective, visual presentation and multiple control scenarios before transitioning to a physical robotic limb. Virtual reality provides us with the opportunity to experiment with multiple perspectives, control schemes and scenarios in a save and rapid way. Finally, it is intended to use a hybrid control system in which computer assistance is combined with cortical control signals. This combined system would be more robust against long-term signal degradation and could provide optimal assistance in activities of daily living for tetraplegic patients.