Noise Evaluation System for Biosignal Sensors Using Pseudo-Skin and Helmholtz Coil
Noise Evaluation System for Biosignal Sensors Using Pseudo-Skin and Helmholtz Coil
复制标题
使用伪皮肤和亥姆霍兹线圈的生物信号传感器噪声评估系统
DOI：
10.1109/ismict.2019.8743712
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Sekitani Tsuyoshi
中科院分区：
文献类型：
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作者：
Inaoka Misaki;Izumi Shintaro;Yoshimoto Shusuke;Nezu Toshikazu;Noda Yuki;Araki Teppei;Uemura Takafumi;Sekitani Tsuyoshi
本研究提出一种可评估生物信号感测器接触电阻与杂讯量之测试装置。由于脑电信号等生物信号的微弱性，很容易被接触电阻产生的噪声所掩盖。为了实现低噪声测量，需要在测量生物信号之前精确地研究生物信号传感器的接触电阻和噪声量。采用导电橡胶制成的伪皮肤模拟传感器的工作环境，客观、有效地评价传感器的性能。该设备由伪皮肤、信号发生电路和线圈组成，信号发生电路用于模拟分钟级的脑电信号和伪嗡嗡声，线圈用于将伪嗡嗡声发射到测试空间中。伪皮肤的接触电阻可以与人类前额的接触电阻相比较。实验结果表明，人造皮肤的接触电阻的标准差为1.70，小于人额头的接触电阻的标准差6.64。这一结果表明，伪皮肤适合于生物信号传感器的接触电阻评估。此外，接触电阻和噪声量之间的相关性进行了评估，以评估系统的有效性。对于接触电阻为32.65 kΩ、85.17 kΩ和405 kΩ的导电凝胶，获得的噪声量分别为597.37 μVrms、1063.09 μVrms和1694.04 μVrms。从结果中观察到噪声量随着接触电阻的增加而增加。为了建立一种有效的生物信号传感器的评价方法，今后需要对该装置进行进一步的改进，并对噪声的评价方法进行深入的研究。
A test equipment that can evaluate the contact resistance and amount of noise of biosignal sensors is proposed in this study. Biosignals such as EEG are easily masked by the noise derived from contact resistance, because of their feebleness. To realize a low-noise measurement, the contact resistance and the amount of noise of biosignal sensors need to be investigated accurately prior to measuring the biosignal. A pseudo-skin made of conductive rubber was employed in this study to evaluate the performance of the sensors objectively and efficiently, similar to actual working conditions. The proposed device is composed of the pseudo-skin, signal-generating circuits to imitate EEG signals and pseudo hum noise on a minute scale, and a coil to emit the pseudo hum noise into the test space. The contact resistance of the pseudo-skin can be compared to that of human foreheads. The experimental results indicated that the standard deviation of the contact resistance of the pseudo-skin is 1.70, which is smaller than that of the human foreheads, which is 6.64. This result demonstrated that the pseudo-skin is suitable for contact resistance evaluation of the biosignal sensors. In addition, the correlation between contact resistance and the amount of noise was evaluated to assess the validity of the system. The amount of noise obtained was 597.37 μVrms, 1063.09 μVrms, and 1694.04 μVrms for the conductive gels with contact resistances of 32.65 kΩ, 85.17 kΩ, and 405 kΩ, respectively. An increase in the amount of noise with the increasing contact resistance was observed from the results. Further improvement of the device and an intensive study of the evaluation method of noise are required in future, in order to establish an efficient evaluation method for biosignal sensors.