Sensory Feedback for upper limb neuroprosthetics

描述(申请人提供)：在这项申请中，我们研究如何提供真实的感觉反馈给使用上肢假肢的受试者。数以千计的士兵从战争中归来，他们需要假肢，这些假肢不仅可以移动，还可以与物体无缝互动。提供反馈的最佳方法是直接利用构成触觉的神经回路。最近的研究表明，SI皮质的3b、1和2区在处理皮肤信息方面起着不同的作用，3b区的神经元负责编码方向，1区负责运动，2区负责曲率。在这项应用中，我们将研究如何通过直接刺激动物大脑皮层这些区域的神经元来提供感觉反馈，这些神经元被训练来执行触觉匹配对样本辨别任务。有两个具体目标。第一个是研究如何在单个指垫上提供强度、方向、运动和曲率的感觉反馈。在训练非人类灵长类动物(猕猴)执行特征辨别任务后，将在体感皮层植入一个慢性记录阵列。录音的目标是同时记录多个神经元，这些神经元与正在研究的特征相适应。然后，这只动物将在三种情况下执行任务。1)将机械刺激与机械刺激相匹配(这是动物被训练执行的条件)；2)将机械刺激与机械和电刺激相匹配；以及3)将机械刺激与电刺激相匹配。电刺激将被给予功能调谐的细胞群体 目的是改变神经元的群体反应。该刺激将以几种方式进行修改，1)改变电流强度，2)改变脉冲的频率，3)改变放电的统计特性(即，仿生的、均匀的、泊松的)，并改变被调制的细胞之间的相关放电的程度。我们将开发系统地改变动物行为的方法，并确定我们是否能够产生模仿触觉刺激反应的群体反应。第二个目标是训练动物执行触觉单人背部任务。这项任务将决定如何刺激大脑皮层，以便刺激 在手指上对电信号进行最小的空间和时间涂抹。这两个目标的结果将提供和理解如何向手提供复杂特征的感觉反馈。

DESCRIPTION (provided by applicant): In this application we investigate how to provide realistic sensory feedback to subjects with upper limb prosthetics. Thousands of soldiers are returning from the war in need of prosthetic limbs that not only can move but also allows them to seamlessly interact with objects. The optimal approach for providing feedback is to tap directly into the neural circuits that underlie tactile perception. Recent studies have shown that areas 3b, 1 and 2 of SI cortex play different roles in processing cutaneous information, with neurons in area 3b responsible for coding orientation, area 1 for motion and area 2 for curvature. In this application we will investigate how to provide sensory feedback by directly stimulation neurons in these cortical areas in animals trained to perform tactile match-to-sample discrimination tasks. There are two specific aims. The first is to investigate how to provide sensory feedback of intensity, orientation, motion and curvature on a single finger pad. After training non-human primates (macaca mulatta) to perform the feature discrimination task, a chronic recording array will be implanted into somatosensory cortex. The goal of the recordings is to simultaneously record from many neurons that are tuned to the feature being studied. The animal will then perform the task under three conditions. 1) Matching a mechanical stimulus with a mechanical stimulus (this is the condition that the animal was trained to perform) 2) Matching a mechanical stimulus with a mechanical and electrical stimulus and 3) Matching a mechanical stimulus with an electrical stimulus. The electrical stimuli will be given to populations of feature tuned cells with the aim of changing the population response of the neurons. This stimulus will be modified in several ways 1) change in current intensity, 2) change in frequency of pulses 3) change in statistical properties of the firing (i.e., biomimetic, uniform, Poisson) and change the degree of correlated firing between cells being modulated. We will develop method to systematically alter the animal's behavior and to determine whether we can produce a population response that mimics the response of the tactile stimulation. The second aim is to train animals to perform a tactile one-back task. This task will determine how to stimulate cortex so that the stimuli can be delivered with minimal spatial and temporal smearing of the electrical signals across fingers. The results from the two aims will provide and understanding of how to provide sensory feedback of complex features to the hand.