Mechanical Engineering, University of Washington, Seattle, WA 98195, USA.
Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA; Washington National Primate Research Center, University of Washington, Seattle, WA 98195, USA.
J Neurosci Methods. 2024 Oct;410:110249. doi: 10.1016/j.jneumeth.2024.110249. Epub 2024 Aug 14.
Accurate real-time eye tracking is crucial in oculomotor system research. While the scleral search coil system is the gold standard, its implantation procedure and bulkiness pose challenges. Camera-based systems are affected by ambient lighting and require high computational and electric power.
This study presents a novel eye tracker using proximity capacitive sensors made of carbon-nanotube-paper-composite (CPC). These sensors detect femtofarad-level capacitance changes caused by primate corneal movement during horizontal and vertical eye rotations. Data processing and machine learning algorithms are evaluated to enhance the accuracy of gaze angle prediction.
The system performance is benchmarked against the scleral coil during smooth pursuits, saccades tracking, and fixations. The eye tracker demonstrates up to 0.97 correlation with the coil in eye tracking and is capable of estimating gaze angle with a median absolute error as low as 0.30°.
The capacitive eye tracker demonstrates good consistency and accuracy in comparison to the gold-standard scleral search coil method.
This lightweight, non-invasive capacitive eye tracker offers potential as an alternative to traditional coil and camera-based systems in oculomotor research and vision science.
精确的实时眼球追踪在眼动系统研究中至关重要。虽然巩膜搜索线圈系统是金标准，但它的植入程序和体积庞大。基于相机的系统受到环境照明的影响，并且需要高计算和电力。
本研究提出了一种使用由碳纳米管纸复合材料 (CPC) 制成的近场电容传感器的新型眼球追踪器。这些传感器检测灵长类动物角膜在水平和垂直眼球转动期间产生的微微法拉级别的电容变化。评估数据处理和机器学习算法以提高注视角度预测的准确性。
该系统的性能在平稳追踪、扫视跟踪和注视期间与巩膜线圈进行了基准测试。眼球追踪器在眼球追踪方面与线圈的相关性高达 0.97，并且能够以低至 0.30°的中位数绝对误差估计注视角度。
与金标准的巩膜搜索线圈方法相比，电容式眼球追踪器在一致性和准确性方面表现良好。
这种轻便、非侵入性的电容式眼球追踪器有望替代传统的线圈和基于相机的系统，用于眼动研究和视觉科学。
