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

项目概要/摘要 快速扫视眼球运动的准确性和及时执行对于有效的视觉至关重要。 因此，需要对眼睛瞄准的位置进行准确测量，不仅要了解对眼睛的影响， 视觉处理，而且也是眼动产生的神经机制 自己40多年来，我们对眼神经系统的理解主要依赖于 巩膜探测线圈系统该系统具有真实的实时性和低噪声的优点， 精度高。然而，它需要侵入性手术来植入眼线圈和大功率AC 电磁场线圈不幸的是，据我们所知，不再有制造商， 供应巩膜探测线圈系统。电子行业的重点转向数字交换 技术淘汰了大多数线性部件，这些部件是构建向场线圈和 检测器不需要附接到眼睛的光学眼动换能器受到以下限制： 视频处理的长延迟。此外，快速高端设备在传输过程中遭受振铃伪像。 这可能会误导扫视运动学的解释。这些问题可能是 一个新的眼神经生理学实验室的屏障。 随着光遗传学的发展，一种允许光操纵细胞活性的技术， 特定的神经元与高时间精度，然后检查对眼球运动的影响，可用性 具有实时特性的眼动跟踪设备是必要的。这种实时、低延迟的要求 在激光脉冲被触发和调制的闭环光遗传学实验中， 由眼球运动的运动学决定。 为了解决对具有高空间和时间分辨率的非接触式眼动传感器的需求， 分辨率，我们建议开发一种眼动跟踪设备，感测眼的非对称几何形状 地球仪。该设备将基于电容传感器，该电容传感器测量地球仪与 传感器.电容式接近传感器具有超过1MHz的宽带宽，并且信号处理 可以使用允许实时操作小信号模拟/数字电路来设计级。的 电容传感器由断裂的碳纳米管-纸复合材料（CPC）组成。不同于其他平面 在电容传感器中，断裂的CPC依赖于由许多CPC的拉伸产生的总表面积。 多壁碳纳米管（MWCNTs）。MWCNT网络的表面积可以足够大， 提供比平面电容器灵敏几个数量级的测量。的 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 巩膜探测线圈系统

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.