Department of Mechanical Engineering, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Department of Psychology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Sensors (Basel). 2024 Jan 15;24(2):0. doi: 10.3390/s24020540.
Electrooculography (EOG) serves as a widely employed technique for tracking saccadic eye movements in a diverse array of applications. These encompass the identification of various medical conditions and the development of interfaces facilitating human-computer interaction. Nonetheless, EOG signals are often met with skepticism due to the presence of multiple sources of noise interference. These sources include electroencephalography, electromyography linked to facial and extraocular muscle activity, electrical noise, signal artifacts, skin-electrode drifts, impedance fluctuations over time, and a host of associated challenges. Traditional methods of addressing these issues, such as bandpass filtering, have been frequently utilized to overcome these challenges but have the associated drawback of altering the inherent characteristics of EOG signals, encompassing their shape, magnitude, peak velocity, and duration, all of which are pivotal parameters in research studies. In prior work, several model-based adaptive denoising strategies have been introduced, incorporating mechanical and electrical model-based state estimators. However, these approaches are really complex and rely on brain and neural control models that have difficulty processing EOG signals in real time. In this present investigation, we introduce a real-time denoising method grounded in a constant velocity model, adopting a physics-based model-oriented approach. This approach is underpinned by the assumption that there exists a consistent rate of change in the cornea-retinal potential during saccadic movements. Empirical findings reveal that this approach remarkably preserves EOG saccade signals, resulting in a substantial enhancement of up to 29% in signal preservation during the denoising process when compared to alternative techniques, such as bandpass filters, constant acceleration models, and model-based fusion methods.
眼动电图(EOG)是一种广泛应用的技术,用于跟踪各种应用中的眼球扫视运动。这些应用包括识别各种医疗状况和开发促进人机交互的接口。然而,EOG 信号常常因存在多种噪声干扰源而受到质疑。这些来源包括脑电图、与面部和眼外肌活动相关的肌电图、电噪声、信号伪影、皮肤电极漂移、随时间的阻抗波动,以及许多相关挑战。解决这些问题的传统方法,如带通滤波,经常被用来克服这些挑战,但也有改变 EOG 信号固有特征的缺点,包括它们的形状、幅度、峰值速度和持续时间,所有这些都是研究中的关键参数。在以前的工作中,已经引入了几种基于模型的自适应去噪策略,包括基于机械和电气模型的状态估计器。然而,这些方法非常复杂,依赖于大脑和神经控制模型,这些模型很难实时处理 EOG 信号。在本研究中,我们提出了一种基于恒定速度模型的实时去噪方法,采用基于物理模型的方法。这种方法的假设是在眼球扫视运动期间,角膜视网膜电位存在一致的变化率。实证研究发现,与带通滤波器、恒定加速度模型和基于模型的融合方法等替代技术相比,这种方法显著地保留了 EOG 扫视信号,在去噪过程中信号的保留率提高了 29%。