Capacitive carbon-nanotube composite eye tracking sensor for non-human primate oculomotor research

项目摘要/摘要 眼球快速跳动的准确性和及时性对有效视力至关重要。 因此，准确测量眼睛瞄准的位置不仅需要了解对眼睛的影响 视觉处理，也包括产生眼球运动的神经机制 他们自己。40多年来，我们对眼球运动系统的大部分了解都依赖于 巩膜探查线圈系统。该系统具有实时运行、噪声低、成本低等优点 精确度高。然而，它需要一个侵入性手术来植入眼圈和笨重的大功率交流 电磁场线圈。不幸的是，据我们所知，不再有制造商 提供巩膜探查线圈系统。电子行业的重心转向数字交换 技术淘汰了制造功率振荡器所需的大多数线性部件，该振荡器为磁场线圈和 探测器。不需要连接到眼睛上的光学眼动换能器受到以下限制 他们视频处理的长等待时间。此外，快速高端设备还会受到 可能会误导对眼跳运动学的解释的眼跳结束。这些问题可能是 一个新的动眼神经生理学实验室的障碍。 随着光遗传学的最新发展，一种允许光操纵细胞活动的技术 具有高时间精度的特定神经元，然后检查对眼球运动的影响，可用 需要一种具有实时特性的眼动跟踪装置。这种实时、低延迟的要求 在触发和调制激光脉冲的闭环光遗传学实验中是必需的 通过眼球运动的运动学，当眼跳展开时。 为了满足对具有高时空特性的非接触式眼动换能器的需求 分辨率，我们建议开发一种能够感知眼睛的不对称几何形状的眼睛跟踪设备 环球网。该装置将基于电容式传感器，测量地球和地球之间的接近程度 传感器。电容式接近传感器具有超过1 mhz的带宽和信号处理。 级可以使用允许实时操作的小信号模拟/数字电路来设计。这个 电容传感器是由断裂的碳纳米管-纸复合材料(CPC)组成的。与其他平面不同 电容式传感器，断裂的CPC依赖于由大量拉伸产生的总表面积 多壁碳纳米管(MWCNTs)MWCNT网络的表面积可以大到足以 提供比平面电容器灵敏数量级的测量结果。这个 所提出的传感器的性能将在非人灵长类动物中进行评估，并与 巩膜探查线圈系统。

Project Summary/Abstract The accuracy and timely execution of rapid saccadic eye movements are crucial for effective vision. Therefore, an accurate measure of where the eye is aimed is required to understand not only the effect on visual processing but also the neuronal mechanisms that underlie the generation of the eye movements themselves. For more than 40 years, much of our understanding of the oculomotor system has relied on the scleral search coil system. This system has the advantages of operating in real time and having low noise and high accuracy. However, it requires an invasive surgery to implant the eye coil and bulky high power AC electromagnetic field coils. Unfortunately, as far as we are aware, there are no longer manufacturers that supply the scleral search coil system. The shifting focus of the electronics industry toward digital switching technology obsoletes most linear parts required to build the power oscillator that feeds the field coils and the detector. The optical eye movement transducers, which do not require attachment to the eye, are limited by the long latency of their video processing. Also, the fast high-end devices suffer from ringing artifacts at the end of a saccade that may mislead the interpretation of saccade kinematics. These problems could be a barrier for a new oculomotor neurophysiology lab. With the recent development of optogenetics, a technique that allows light to manipulate the activity of specific neurons with high temporal precision and then examine the effects on eye movements, the availability of an eye tracking device with a real-time characteristics is necessary. This real-time, low latency requirement is necessary in a closed-loop optogenetics experiment in which the laser light pulse is triggered and modulated by the kinematics of the eye movement while a saccade is unfolding. To address the need for a non-contact eye movement transducer with high spatial and temporal resolution, we propose to develop an eye tracking device that senses the asymmetric geometry of the ocular globe. The device will be based on a capacitive sensor that measures the proximity between the globe and the sensor. A capacitive proximity sensor has a wide bandwidth in excess of 1MHz and the signal processing stage can be designed using small-signal analog/digital circuits that allow for real-time operation. The capacitance sensor is composed of a fractured carbon nanotube-paper composite (CPC). Unlike other planar capacitive sensors, the fractured CPC relies on the total surface area resulting from the stretching of numerous multi-walled carbon nanotubes (MWCNTs). The surface area of MWCNT networks can be large enough to provide measurements that are orders of magnitude more sensitive than that of planar capacitors. The performance of the proposed sensor will be evaluated in a non-human primate and compared to that of a scleral search coil system.