Wyckoff Sarah N, Sherlin Leslie H, Ford Noel Larson, Dalke Dale
SenseLabs, Mesa, Arizona, Atascadero, CA, USA.
Department of Psychology, Northern Arizona University, Flagstaff, AZ, USA.
J Neuroeng Rehabil. 2015 Oct 31;12:95. doi: 10.1186/s12984-015-0089-2.
Electroencephalography (EEG) is a widely used neuroimaging technique with applications in healthcare, research, assessment, treatment, and neurorehabilitation. Conventional EEG systems require extensive setup time, expensive equipment, and expertise to utilize and therefore are often limited to clinical or laboratory settings. Technological advancements have made it possible to develop wireless EEG systems with dry electrodes to reduce many of these barriers. However, due to the lack of homogeneity in hardware, electrode evaluation, and methodological procedures the clinical acceptance of these systems has been limited.
In this investigation the validity of a wireless dry electrode system compared to a conventional wet electrode system was assessed, while addressing methodological limitations. In Experiment 1, the signal output of both EEG systems was examined at Fz, C3, Cz, C4, and Pz using a conductive head model and generated test signals at 2.5 Hz, 10 Hz, and 39 Hz. In Experiment 2, two-minutes of eyes-closed and eyes-open EEG data was recorded simultaneously with both devices from the adjacent electrode sites in a sample of healthy adults.
Between group effects and frequencydevice and electrodedevice interactions were assessed using a mixed ANOVA for the simulated and in vivo signal output, producing no significant effects . Bivariate correlation coefficients were calculated to assess the relationship between electrode pairs during the simultaneous in vivo recordings, indicating a significant positive relationship (all p's < .05) and larger correlation coefficients (r > ± 0.5) between the dry and wet electrode signal amplitude were observed for theta, alpha, beta 1, beta 2, beta 3, and gamma in both the eyes-closed and eyes-open conditions.
This report demonstrates preliminary but compelling evidence that EEG data recorded from the wireless dry electrode system is comparable to data recorded from a conventional system. Small correlation values in delta activity were discussed in relation to minor differences in hardware filter settings, variation in electrode placement, and participant artifacts observer during the simultaneous EEG recordings. Study limitations and impact of this research on neurorehabilitation were discussed.
脑电图（EEG）是一种广泛应用的神经成像技术，在医疗保健、研究、评估、治疗和神经康复等领域均有应用。传统的脑电图系统需要大量的设置时间、昂贵的设备以及专业知识来操作，因此通常仅限于临床或实验室环境使用。技术的进步使得开发带有干电极的无线脑电图系统成为可能，从而减少了许多此类障碍。然而，由于硬件、电极评估和方法程序缺乏同质性，这些系统在临床上的接受度一直有限。
在本研究中，在解决方法学局限性的同时，评估了一种无线干电极系统与传统湿电极系统相比的有效性。在实验1中，使用导电头部模型并在2.5赫兹、10赫兹和39赫兹产生测试信号，在Fz、C3、Cz、C4和Pz处检查了两种脑电图系统的信号输出。在实验2中，使用这两种设备同时从健康成年人样本的相邻电极部位记录了两分钟闭眼和睁眼的脑电图数据。
对于模拟和体内信号输出，使用混合方差分析评估组间效应以及频率设备和电极设备的相互作用，未产生显著影响。计算双变量相关系数以评估同步体内记录期间电极对之间的关系，结果表明存在显著正相关关系（所有p值均<0.05），并且在闭眼和睁眼条件下，对于θ波、α波、β1波、β2波、β3波和γ波，观察到干电极和湿电极信号幅度之间的相关系数更大（r>±0.5）。
本报告展示了初步但令人信服的证据，即从无线干电极系统记录的脑电图数据与从传统系统记录的数据具有可比性。讨论了δ活动中较小的相关值与硬件滤波器设置的微小差异、电极放置的变化以及同步脑电图记录期间参与者伪迹观察者之间的关系。讨论了研究局限性以及本研究对神经康复的影响。
