Abstract For achieving the room temperature magnetoencephalography (MEG) and magnetocardiography (MCG) measurements in an unshielded environment, we have developed a high performance, pico-tesla resolution magnetoimpedance (MI) sensor system with the peak-to-peak voltage detector, by synchronized switching. We have achieved a high field detection sensitivity with good linearity, and a noise level lower than 1 pT/Hz1/2, by utilizing the time-differential measurement in each MI element for suppressing the low frequency noise components and increasing the stability of sensor system. We have successfully developed a Pk–pk VD-type MI sensor system aiming to measure the room-temperature real-time alpha rhythm signals, and demonstrated a clear sensitivity for spontaneous brain activity with SNR of about 8. The considerable enhancement of alpha rhythm measured by new MI sensor system in each eyes-closed condition is further evidence that these recorded signals are emanating from spontaneous brain activity. Meanwhile, we have also achieved the real time MCG measurements via pk-pk VD-type MI sensor system, with a high real time SNR of about 14 dB, and successfully measured the T wave and R wave of MCG signals, in averaging over 10 cycles, with a high SNR of more than 20 dB. Index Terms— Magneto-impedance (MI) sensor, Magnetoencephalogram (MEG), Magnetocardiography (MCG), Amorphous wire.

中文翻译：

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用于生物磁场测量的皮特斯拉分辨率非晶线磁阻抗传感器的开发

摘要 为了在非屏蔽环境中实现室温脑磁图 (MEG) 和心磁图 (MCG) 测量，我们开发了一种高性能、皮特斯拉分辨率的磁阻抗 (MI) 传感器系统，该系统具有峰峰值电压检测器，通过同步交换。我们通过在每个 MI 元件中利用时差测量来抑制低频噪声分量并增加传感器系统的稳定性，实现了高场检测灵敏度和良好的线性度，以及低于 1 pT/Hz1/2 的噪声水平. 我们已经成功开发了一种旨在测量室温实时 alpha 节律信号的 Pk-pk VD 型 MI 传感器系统，并展示了对自发大脑活动的明确敏感性，信噪比约为 8。在每个闭眼条件下，新的 MI 传感器系统测量的 alpha 节律的显着增强进一步证明这些记录的信号来自自发的大脑活动。同时，我们还通过pk-pk VD型MI传感器系统实现了实时MCG测量，实时信噪比高达14dB左右，成功测量了MCG信号的T波和R波，平均超过10周期，具有超过 20 dB 的高 SNR。索引词——磁阻抗 (MI) 传感器、脑磁图 (MEG)、心磁图 (MCG)、非晶线。具有14dB左右的高实时信噪比，并成功测量了MCG信号的T波和R波，平均超过10个周期，具有超过20dB的高信噪比。索引词——磁阻抗 (MI) 传感器、脑磁图 (MEG)、心磁图 (MCG)、非晶线。具有14dB左右的高实时信噪比，并成功测量了MCG信号的T波和R波，平均超过10个周期，具有超过20dB的高信噪比。索引词——磁阻抗 (MI) 传感器、脑磁图 (MEG)、心磁图 (MCG)、非晶线。