Bartuzel Maciej M, Wróbel Krystian, Tamborski Szymon, Meina Michał, Nowakowski Maciej, Dalasiński Krzysztof, Szkulmowska Anna, Szkulmowski Maciej
Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, Toruń 87-100, Poland.
Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wyb. Wyspiańskiego 27, Wrocław 50-370, Poland.
Biomed Opt Express. 2020 May 19;11(6):3164-3180. doi: 10.1364/BOE.392849. eCollection 2020 Jun 1.
We introduce a novel, noninvasive retinal eye-tracking system capable of detecting eye displacements with an angular resolution of 0.039 arcmin and a maximum velocity of 300°/s across an 8° span. Our system is designed based on a confocal retinal imaging module similar to a scanning laser ophthalmoscope. It utilizes a 2D MEMS scanner ensuring high image frame acquisition frequencies up to 1.24 kHz. In contrast with leading eye-tracking technology, we measure the eye displacements via the collection of the observed spatial excursions for all the times corresponding a full acquisition cycle, thus obviating the need for both a baseline reference frame and absolute spatial calibration. Using this approach, we demonstrate the precise measurement of eye movements with magnitudes exceeding the spatial extent of a single frame, which is not possible using existing image-based retinal trackers. We describe our retinal tracker, tracking algorithms and assess the performance of our system by using programmed artificial eye movements. We also demonstrate the clinical capabilities of our system with subjects by detecting microsaccades with angular extents as small as 0.028°. The rich kinematic ocular data provided by our system with its exquisite degree of accuracy and extended dynamic range opens new and exciting avenues in retinal imaging and clinical neuroscience. Several subtle features of ocular motion such as saccadic dysfunction, fixation instability and abnormal smooth pursuit can be readily extracted and inferred from the measured retinal trajectories thus offering a promising tool for identifying biomarkers of neurodegenerative diseases associated with these ocular symptoms.
我们介绍了一种新型的非侵入性视网膜眼动追踪系统，该系统能够检测眼睛位移，角分辨率为0.039角分，在8°跨度内的最大速度为300°/秒。我们的系统基于一个类似于扫描激光检眼镜的共焦视网膜成像模块设计。它利用二维微机电系统（MEMS）扫描仪，确保高达1.24kHz的高图像帧采集频率。与领先的眼动追踪技术相比，我们通过收集与一个完整采集周期对应的所有时刻观察到的空间偏移来测量眼睛位移，从而无需基线参考帧和绝对空间校准。使用这种方法，我们展示了对幅度超过单帧空间范围的眼睛运动的精确测量，这是现有基于图像的视网膜追踪器无法做到的。我们描述了我们的视网膜追踪器、追踪算法，并通过使用编程的人工眼动来评估我们系统的性能。我们还通过检测角幅度小至0.028°的微扫视，展示了我们系统在受试者身上的临床能力。我们的系统提供的丰富的运动学眼部数据及其极高的精度和扩展的动态范围，为视网膜成像和临床神经科学开辟了新的、令人兴奋的途径。眼部运动的几个微妙特征，如扫视功能障碍、注视不稳定和异常平稳追踪，可以很容易地从测量的视网膜轨迹中提取和推断出来，从而为识别与这些眼部症状相关的神经退行性疾病的生物标志物提供了一个有前景的工具。
